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Impedance or current regulator in the supply circuit

Subclass of:

315 - Electric lamp and discharge devices: systems

315209000 - PERIODIC SWITCH IN THE SUPPLY CIRCUIT

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DocumentTitleDate
20110175538LAMP DRIVING APPARATUS AND LEVEL SHIFT DRIVING CIRCUIT - A lamp driving apparatus includes a switch module, a controller, a resonant module, and a level shift circuit. The switch module includes a high side transistor switch and a low side transistor switch connected in series between an input power source and a common level. The controller controls the high side and the low side transistor switches to control the power from the input power source transmitted through the switch module. The resonant module coupled to the switch module converts the power into an AC output signal to drive a lamp. The level shift circuit generates a high side control signal based on an voltage level of a connecting node of the high side and the low side transistor switches, the level shift voltage, and a control signal generated by the controller so as to control the high transistor switch.07-21-2011
20130026941SINGLE WAVELENGTH LIGHT SOURCE FOR USE IN LIGHT BASED POSITIONING SYSTEM - In one aspect, the present disclosure relates to a self identifying single wavelength light source including an emitter that produces a single wavelength of visible light; and an autonomous modulator in electrical communication with the emitter that automatically and continually modulates the single wavelength of visible light produced by the emitter, wherein the modulated single wavelength of visible light represents an identification code of the light source. In some embodiments, the emitter is a light emitting diode (LED) and further includes an LED driver that provides a specified voltage and current to each LED in the light source. In some embodiments, the emitter can be a blue light emitting diode (LED).01-31-2013
20130026940SELF IDENTIFYING MODULATED LIGHT SOURCE - In one aspect, the present disclosure relates to a self identifying light source including an emitter that produces visible light; and an autonomous modulator in electrical communication with the emitter that automatically and continually modulates the visible light produced by the emitter, wherein the modulated visible light represents an identification code of the light source. In some embodiments, the emitter is a light emitting diode (LED) and further comprising an LED driver that provides a specified voltage and current to each LED in the light source.01-31-2013
20130026939PULSE WIDTH MODULATION CIRCUIT AND ILLUMINATION APPARATUS - An illumination apparatus includes a power supply, a pulse width modulation (PWM) circuit, a switching unit, and an illuminating unit. The power supply supplies a supply voltage to the PWM circuit and the illuminating unit. The PWM circuit outputs a first level voltage by being fully charged by the voltage of the power supply and outputs a second level voltage by being fully discharged. The switching unit is turned off according to the first level voltage and controls the illuminating unit to stop emitting light. The switching unit is turned on according to the second level voltage and controls the illuminating unit to emit light.01-31-2013
20130026938DISCHARGE LAMP SYSTEM AND METHOD FOR CONTROLLING DISCHARGE LAMP - A discharge lamp system includes a discharge lamp, a power source, a converter, a lamp state signal detection module and a controller. The power source provides a DC power. The converter converts the DC power into a current required by the discharge lamp. The lamp state signal detection module receives a lamp state signal and outputs a lamp state detection signal. The controller processes the lamp state detection signal and a given synchronization signal to generate an average lamp current signal and a pulse current signal, and then processes the average lamp current signal and the pulse current signal to generate a control signal. The controller performs current control of the discharge lamp through the converter according to the control signal. Furthermore, a method for controlling a discharge lamp is also disclosed herein.01-31-2013
20100060180CIRCUIT ARRANGEMENT FOR IGNITING AND OPERATING A DISCHARGE LAMP - A circuit arrangement for igniting and operating a gas discharge lamp having a half-bridge arrangement, which acts as a step-down inverter in quasi-resonant mode, a lamp inductor and a resonance capacitor that form a resonant circuit, and having an ignition transformer whose secondary winding is connected on the one hand to a lamp electrode and is connected on the other hand to the tie point between the lamp inductor and resonance capacitor, wherein the primary winding of the ignition transformer is connected with its first end to the tie point between the lamp inductor and resonance capacitor, and with its second end to the tie point of two series connected diodes, the first diode being connected to the power supply unit, and the second diode being connected to circuit ground.03-11-2010
20100019682LED driver and controller thereof - A LED driver is disclosed for providing a current for LED lighting. The LED driver includes an inductor and a controller having a power switch, and the inductor, the power switch and a LED to be driven are configured to be an asynchronous boost converter. Because the driven LED serves as a rectifier diode of the asynchronous boost converter, the controller may have fewer components and requires smaller die area.01-28-2010
20100013399LIGHTING METHOD FOR A HIGH-PRESSURE DISCHARGE LAMP, LIGHTING CIRCUIT FOR A HIGH-PRESSURE DISCHARGE LAMP, HIGH-PRESSURE DISCHARGE LAMP APPARATUS, AND PROJECTOR-TYPE IMAGE DISPLAY APPARATUS - After startup, a lighting method for a high-pressure discharge lamp is to light the lamp at a rated frequency without switching the frequency for 120 seconds (S01-21-2010
20100084987DISCHARGE LAMP DRIVING DEVICE AND METHOD, LIGHT SOURCE DEVICE, AND IMAGE DISPLAYING APPARATUS - In at least one embodiment of the disclosure, a discharge lamp driving device includes a discharge lamp lighting unit configured to supply power to a discharge lamp while alternately switching a polarity of a voltage applied across two electrodes of the discharge lamp. A controller performs a modulation control of the power in accordance with a power ratio characterized by the power supplied in a polarity switching period. The controller starts the modulation control at a predetermined time after the power supplied to the discharge lamp reaches a predetermined power value.04-08-2010
20100164390LIGHT SOURCE AND METHOD FOR PRODUCING LIGHT MODIFIABLE IN COLOUR AND/OR LUMINOSITY - The present invention relates to a light source, which produces light leaving the light source with modifiable colour and luminosity, with at least one light emitting diode for emitting primary radiation, comprising a layer connected with said diode, wherein said layer includes at least one luminescent material for converting the primary radiation into a secondary radiation.07-01-2010
20100164391POWER SUPPLY APPARATUS AND METHOD FOR AMOLED - A power supply apparatus and method for an active matrix organic light emitting diode (AMOLED) is disclosed. The power supply apparatus supplies power to the AMOLED while using a switching frequency varied in accordance with a clock signal, and includes a load checker for comparing a load current of the AMOLED with a first reference voltage, and outputs a result of the comparison as a load check signal, and a frequency oscillator for generating the clock signal which has a variable frequency in response to the load check signal. The power supply apparatus is switched in accordance with a clock signal having a frequency modulated based on a load condition of the AMOLED, for example, a load current. Accordingly, it is possible to reduce switching power loss caused by unnecessary power consumption under the condition that a small load current is generated, thereby achieving an enhancement in efficiency.07-01-2010
20080258640Discharge lamp lighting apparatus - A discharge lamp lighting apparatus includes: an inverter circuit; a lamp current detecting portion; and a burst mode control circuit which includes a noise reduction circuit including: an error amplification circuit to receive a feedback signal from the lamp current detecting portion; and a frequency response reduction circuit connected to the error amplification circuit, wherein the frequency response reduction circuit receives a dimming pulse signal for the burst mode dimming control, and the response characteristic of the noise reduction circuit is lowered while the dimming pulse signal is outputted, whereby the lamp current waveforms is suppressed from making a sharp change at the time of burst dimming control.10-23-2008
20130038233LED DRIVER - A light-emitting diode (LED) driver is provided. The LED driver, providing a drive voltage for driving an LED circuit according to an input voltage, includes a current regulator, a dimming signal generator, and a boost converter. In response to a pulse width modulation (PWM) dimming signal, the current regulator enables the LED circuit in a first PWM period and disables the LED circuit outside the first PWM period. The dimming generator generates a prolonged PWM dimming signal according to the PWM dimming signal. The prolonged PWM dimming signal has a prolonged period, a length of which is associated with a level of an input voltage. In response to the prolonged PWM dimming signal, the boost converter is enabled in a second PWM period and maintains a level of the drive voltage according to the input voltage.02-14-2013
20130033192BACKLIGHT UNIT AND APPARATUS AND METHOD FOR CONTROLLING LED DRIVING CIRCUIT - A backlight unit is provided. The backlight unit includes an LED; an LED driving unit which drives the LED in accordance with a switching operation of a transistor; and a control unit which adds an additional signal to an output current of the LED to obtain a combined current, compares the combined current with the reference current, and controls the switching operation of the transistor based on the results of the comparison, wherein the additional signal is a current signal whose level increases over time in each period and is then reset to a predefined value in each period in accordance with an operation cycle of the transistor.02-07-2013
20130033191LIGHT EMITTING DIODE DRIVING DEVICE AND METHOD THEREOF - There are provided a light emitting diode (LED) driving device allowing for an increase in an LED driving rate by discharging a charge stored in a capacitor during a certain period of time and a method thereof. The LED driving device includes: a driving unit detecting a current, as a voltage, the current flowing across an LED unit having at least one LED, controlling the current flowing across the LED unit according to a comparison result between the detected voltage and a reference voltage having a pre-set voltage level, and having a capacitor stabilizing an operation of the LED unit when the LED unit is driven; and a discharging unit discharging a charge stored in the capacitor during a pre-set discharge time when the LED unit is initially driven.02-07-2013
20100039038Electronic ballast with high power factor - This invention provides an electronic ballast for a fluorescent lamp, including a rectifier for converting an alternating current input voltage into a direct current output voltage, and a circuit including a combined power factor correction (PFC) stage and an inverter, wherein the PFC stage and the inverter share a switch. Also provided is a controller for an electronic ballast, including a duty ratio controller that controls a duty ratio of a switch of the ballast, and means for adjusting the duty ratio according to a nonlinear function, so that an arc is sustained across the lamp. The controller and the ballast allow dimming of the fluorescent lamp while maintaining a high power factor.02-18-2010
20130033193METHOD AND APPARATUS FOR ADJUSTING LIGHT OUTPUT RANGE OF SOLID STATE LIGHTING LOAD BASED ON MAXIMUM AND MINIMUM DIMMER SETTINGS - A method is provided for controlling a power converter (02-07-2013
20100045196CIRCUIT ARRANGEMENT FOR FIRING A DISCHARGE LAMP - A circuit arrangement for starting a discharge lamp, comprising: a first and a second input terminal for connecting an input voltage; an inverter, which has an input and an output, the input being coupled to the first and the second input terminal; a first and a second output terminal for connecting the discharge lamp; a resonant inductor, which is coupled between the output of the inverter and the first output terminal; a resonant circuit, which comprises the resonant inductor; a regulating apparatus for regulating the frequency of the signal provided at the inverter output; and a current measuring apparatus, which is arranged so as to measure a current which is correlated with the current in the resonant circuit, wherein the regulating apparatus is adapted to regulate the frequency at the output of the inverter as a function of the measured current.02-25-2010
20130038232LIGHT UNIT AND DRIVING METHOD THEREOF - A light unit includes: an integrated power (“IP”) board which receives power supply and converts the power supply into a high voltage and a supply voltage; a lamp; and a terminal board (“T board”) which receives the high voltage from the IP board to turn on the lamp, receives the supply voltage from the IP board to transfer the supply voltage to the IP board, in which the IP board transfers the high voltage to the T board after the IP board receives the supply voltage from the T board.02-14-2013
20100102739CIRCUIT FOR CONTROLLING A FLUORESCENT LAMP, METHOD FOR OPERATING THE CIRCUIT, AND SYSTEM COMPRISING THE CIRCUIT - In various embodiments, a circuit for driving a fluorescent lamp is provided. The circuit may include a half bridge including a first switch and a second switch; a drive unit for driving the first switch and the second switch, it being possible for a predetermined state to be established using the drive unit, and it being possible for the driving of the first and the second switch to be modulated as a result of the predetermined state using the drive unit.04-29-2010
20100097003HIGH-VOLTAGE DISCHARGE LAMP LIGHTING APPARATUS - In a high-voltage discharge lamp lighting apparatus for lighting a high-voltage discharge lamp, a digital control circuit synchronizes an ON/OFF state of a semiconductor switching element included in a step-down chopper circuit with an ON/OFF state of semiconductor switching elements included in an inverter circuit, and controls an ON time of the semiconductor switching element included in the step-down chopper circuit at the same or substantially the same time as a polarity reversal time in an alternating current waveform of the inverter circuit. As a result, in the high-voltage discharge lamp lighting apparatus in which rapid polarity reversal is required, the occurrence of overshoot and undershoot in the waveform of an alternating current passing through a high-voltage discharge lamp is reliably prevented.04-22-2010
20130038234DIMMING REGULATOR INCLUDING PROGRAMMABLE HYSTERETIC DOWN-CONVERTER FOR INCREASING DIMMING RESOLUTION OF SOLID STATE LIGHTING LOADS - A system providing deep dimming of a solid state lighting (SSL) load includes a hysteretic down-converter, a shunt switch, a controller and a comparator. The down-converter controls average current value and amplitude of ripple of SSL current using amplitude modulation (AM) dimming control. The shunt switch controls magnitude of the SSL current using pulse width modulation (PWM) dimming control. The controller generates first and second PWM signals for controlling upper and lower current levels at which the down-converter operates based on the SSL current and voltage across the SSL load, and generates a third PWM signal for controlling the shunt switch based on a dimming level load set by a dimmer. The comparator circuit compares first and second analog signals corresponding to the first and second PWM signals with the SSL current, and drives the down-converter in response to the comparison. The SSL current is based on both the AM dimming control and the PWM dimming control.02-14-2013
20130038231METHOD AND APPARATUS OF CONTROLLING DISCHARGE LAMP AND DISCHARGE LAMP SYSTEM - A method and a device for controlling a discharge Lamp, and a discharge lamp system are disclosed herein. The method includes the operations of: when the lamp current changes, determining a percentage of change of the lamp current according to a synchronous signal and obtaining a second lamp current after a discharge lamp current changes according to the percentage of change of the lamp current and a first lamp current; obtaining a modulating signal according to a current difference between the first lamp current and the second lamp current; and generating a pulse voltage signal according to the modulating signal. The pulse voltage signal transits from a first voltage to a second voltage during the time period when the lamp current is transited from a first lamp current to a second lamp current during a transition time.02-14-2013
20100109543HIGH-PRESSURE DISCHARGE LAMP BALLAST WITH MULTI-MODE LAMP STARTING CIRCUIT - An electronic ballast is provided for powering a high-pressure discharge lamp. A power supply circuit receives an AC input and provides a DC output in response to the AC input. An inverter circuit having a plurality of switching elements converts the DC output into an AC signal for the lamp. An LC resonant circuit is coupled between the inverter circuit and the lamp. A control circuit controls the switching operation of the switching elements, with the switching control associated with various operating modes. In an electrical breakdown mode the switching elements are controlled at a first switching frequency effective to provide a first resonant voltage and produce electrical breakdown of the lamp from an unlit state. In a high frequency preheat mode the switching elements after startup of the lamp are controlled at a second switching frequency lower than the first switching frequency to provide a current for preheating lamp electrodes. In a rectangular wave lighting mode the switching elements after preheating of the lamp electrodes is controlled to supply a rectangular wave AC signal to the lamp and maintain steady state lighting.05-06-2010
20100109541COLOR CONTROL OF LIGHT SOURCES EMPLOYING PHOSPHORS - An illuminating device includes a light source including a lighting device, such as a solid state lighting device, which emits light, a phosphor material which converts at least a portion of the light emitted by the lighting device to light of a different wavelength. A controller adjusts a ratio of on time to off time of a current waveform supplied to the lighting device. This enables the color of light emitted by the light source to be controlled.05-06-2010
20100109542ELECTRONIC BALLAST WITH CONTROLLED LAMP PREHEATING - An electronic ballast provides controlled preheating for a discharge lamp. A power converting circuit receives a DC power input and converts it into an AC power output. A starting circuit coupled to the power converting circuit generates a high voltage for starting the lamp. A control circuit controls the power converting circuit to generate AC power output to the lamp dependent on a mode of operation. A symmetry detecting circuit determines a positive-negative symmetrical state of the output power provided to the discharge lamp with respect to ground. The control circuit has a starting mode wherein the discharge lamp is triggered to start with a high voltage generated by the starting circuit, an electrode heating mode wherein the AC power output of the power converting circuit is controlled to a first frequency for heating each lamp electrode, and a steady-state mode wherein the AC power output of the power converting circuit is controlled to a second frequency for maintaining lighting of the discharge lamp. The control circuit shifts from the electrode heating mode to the steady-state mode when the symmetry detecting circuit determines that the AC power output is in a positive-negative symmetrical state in the electrode heating operation.05-06-2010
20130026942DEVICE FOR DIMMING A BEACON LIGHT SOURCE USED IN A LIGHT BASED POSITIONING SYSTEM - In one aspect, the present disclosure relates to a dimmable beacon light source for a light based positioning system. In some embodiments, the light source includes a dimmer control switch configured to generate a dimmer signal having a desired light output level, a dimmable driver for controlling the light output of the light source, and a modulator for receiving the dimmer signal from the dimmer control switch, generating a digital pulse recognition signal by controlling the frequency of the dimmer signal to a desired frequency value, and transmitting the digital pulse recognition signal to the dimmable driver to drive the light output of the light source. In some embodiments, the digital pulse recognition signal is a pulse width modulated signal. In some embodiments, the digital pulse recognition signal has a duty cycle based on the dimmer signal.01-31-2013
20130082619CURRENT GENERATING CIRCUIT AND LED DRIVING CIRCUIT - A current generating circuit, for generating an output current to a target device, comprising: a current generating module; a grad power detecting circuit, for receiving a grad power signal and for generating a grad power detecting signal according to a voltage of the grad power signal; a feedback circuit, for generating a first feedback signal and a second feedback signal according to the output current; and a voltage converting controller, comprising a first input terminal and a second input terminal, wherein the first input terminal receives a grad power coupling signal generated by coupling the first feedback signal and the grad power detecting signal, and the second input terminal receives the second feedback signal, where the voltage converting controller controls the current generating module to generate the output current according to the grad power coupling signal and the second feedback signal.04-04-2013
20100026197DRIVING REGULATION METHOD FOR BIPOLAR TRANSISTORS IN ELECTRONIC BALLAST AND THE DEVICE THEREOF - A method of driving regulation for bipolar transistors in electronic ballast is provided. The method may include: sensing voltage at midpoint of half bridge of the transistors; producing a reference time signal according to a sync signal from a timer; producing actual time interval in this cycle by comparing rising edge of the voltage at midpoint of the half bridge of the transistors with rising edge of a driving signal for the transistors in upper bridge arm in each switching cycle; comparing the actual time interval with the reference time signal to determine pulse width of the driving signal; regulating, in which the driving signal in this switching cycle is prolonged relative to the driving signal in previous switching cycle if the actual time interval is larger than the reference time signal, while the driving signal in this switching cycle is shortened relative to the driving signal in previous switching cycle if the actual time interval is smaller than the reference time signal.02-04-2010
20090045756Cold Cathode Tube Drive Device - A cold-cathode tube drive device includes an inverter circuit (02-19-2009
20120181945ELECTRONIC BALLAST AND METHOD FOR OPERATING AT LEAST ONE DISCHARGE LAMP - In various embodiments, ballast for a discharge lamp includes input and output connections; inverter with bridge circuit with electronic switches and control device for controlling electronic switches, wherein switches are connected in series between input connections, wherein one electronic switch is coupled to first input connection and second electronic switch to second input connection, wherein a bridge midpoint is between electronic switches; including a current measuring device for measuring second electronic switch current; lamp choke series-connected between bridge midpoint and first output connection; capacitor parallel-connected with one of electronic switches; and coupling capacitor; wherein control device is coupled to current measuring device and renders an electronic switch conducting, if negative threshold value is exceeded when electronic switch is rendered nonconducting; or if negative threshold value of current through electronic switch is not exceeded after another electronic switch is rendered nonconducting, wherein control device increases first frequency in second case.07-19-2012
20120181944METHOD AND APPARATUS PROVIDING DEEP DIMMING OF SOLID STATE LIGHTING SYSTEMS - Disclosed are devices and related methods for optimally extending the range of light output of solid-state light sources, particularly at minimum light levels, through a power converter that includes a phase detector, a processing unit and a switch. The phase detector is configured to receive a voltage signal and to detect rising edges of waveforms of the voltage signal. The processing unit is configured to initiate a predetermined shutdown period in response to each detected rising edge. The switch is configured to provide a control signal that deactivates the power converter during the shutdown period, preventing the power converter from providing power to the solid state light unit during the shutdown period.07-19-2012
20130049623LED DRIVE CIRCUIT AND LED DRIVING METHOD - An LED drive circuit of the present invention carries out, by use of a DC-to-DC converter, light control of an LED. The light control is carried out, in a region where a light control level is equal to or greater than a certain light control level, by a DC light control method for adjusting a pulse height of an LED drive current. The light control is carried out, in a region where a light control level is equal to or less than the certain light control level, by a PDM light control method for adjusting an off period of oscillation of the DC-to-DC converter.02-28-2013
20130049625Discharge-Lamp Lighting Device - A lighting device has a direct-current power generation circuit, a rectangular-wave generation circuit, a pulse generating circuit, lamp-voltage detection means, and pulse-generation command means. The direct-current power generation circuit generates direct-current power from external power. The rectangular-wave generation circuit converts the direct-current power to rectangular-wave alternating-current power. The pulse generating circuit superposes high-voltage pulses on the rectangular-wave power output from the rectangular-wave generation circuit and starts a discharge lamp. The lamp-voltage detection means detects, in digital form, a lamp voltage supplied to the discharge lamp. The pulse-generation command means issues a pulse generation command to the pulse generating circuit when the value detected by the lamp-voltage detection means reaches a predetermined no-load-voltage determination level.02-28-2013
20130049624Lighting Device - A lighting device has a power-factor correction circuit 02-28-2013
20100134029METHOD OF IGNITION REGULATION OF DISCHARGE LAMP AND THE CORRESPONDING ELECTRONIC BALLAST CIRCUIT - A method and corresponding electronic ballast circuit for regulating the ignition voltage of a discharge lamp is described. The circuit includes a discharge lamp with an AC operating voltage supplied by a half-bridge inverter circuit comprising two transistors. The method includes detecting the current flowing through one transistor of the two transistors, and comparing the detected current with a predetermined reference value. When the detected current exceeds a predetermined reference value, a driving period of the one transistor is terminated and the driving period of the other transistor of said two transistors is started, and the driving period of said other transistor is made to be the same as the terminated driving period of the one transistor.06-03-2010
20130069555DIMMER-DISABLED LED DRIVER - An integrated circuit controller for use in a light emitting diode (LED) driver includes a comparator, an input signal absence timer and a regulator circuit. The comparator receives a first voltage representative of an ac input signal and compares the first voltage with a reference voltage. The input signal absence timer determines whether the first voltage is less than the reference voltage for a threshold duration and in response thereto generates a detect signal indicating that a portion of an ac half cycle is absent from the ac input signal. The regulator circuit controls switching of a switch to regulate a transfer of energy from the ac input signal to an LED load. The regulator circuit is disabled from switching the switch in response to the detect signal indicating the absence of the portion of the ac half cycle from the ac input signal.03-21-2013
20130069552ORGANIC ELECTROLUMINESCENT DEVICE WITH SPACE CHARGE/VOLTAGE INSTABILITY STABILIZATION DRIVE - An organic light emitting electrical device containing an organic light emitting diode (OLED) and a power supply adapted to reduce space charge buildup in the OLED. An organic electroluminescent device has an organic light emitting diode with a first electrode and a second electrode. A power supply is electrically coupled to the first electrode and the second electrode. The power supply is configured to generate a forward bias voltage and a reverse bias voltage pulse and alternately connect the forward bias voltage to the first electrode and the second electrode, and the reverse bias voltage pulse to the second electrode and the first electrode.03-21-2013
20130069554DRIVING DEVICE - A driving device comprises a first transistor (B03-21-2013
20130069553LED DIMMING DRIVE DEVICE, METHOD AND LCD - A light emitting diode (LED) dimming drive device, an LED dimming drive method and a liquid crystal display (LCD) are disclosed. The LED dimming drive device comprises a plurality of dimming control circuits each comprising one dimmer switch and a delay setting circuit for setting a different delay time for each dimming control circuits. Each of the dimming control circuits further comprises a clock delay circuit for receiving a pulse width modulation (PWM) signal, timing according to the delay time, and outputting the PWM signal to the dimmer switch when the delay time expires. Different delay times can be used to control the output of PWM signals and further control the on or off of the dimmer switches. This can avoid the noises or electromagnetic (EM) interferences occurred by a large amount of energy transmitted into the LED paths when the dimmer switches is turned on.03-21-2013
20120217890DRIVING CIRCUIT FOR LED - A driving circuit for driving a load is provided. The driving circuit includes a control module providing a control signal to adjust a load current flowing through the load; and a voltage clamping module providing a power voltage to the control module.08-30-2012
20110006696MULTIFUNCTIONAL OUTPUT STAGE FOR DRIVING DIMMED LIGHT SOURCES AND RELATED METHOD - A drive arrangement for light sources may include: a connection line to feed a light source, a switch element coupled to said line to apply on/off signals to said line, and a controller to control operation of said switch, said controller being sensitive to at least one of a dimming signal representative of a desired dimming level for said light source and an information-carrying digital signal, wherein said controller is configured to control operation of said switch to: a) PWM modulate an on/off signal applied to said line as a function of said dimming signal, whereby the average current conveyed towards said light source and determined by said PWM modulated on/off signal controls the brightness of said light source, b) transmit said information-carrying digital signal as an on/off information signal applied to said line, whereby the information carried by said information-carrying digital signal is transmitted over said line.01-13-2011
20130057174LIGHT-EMITTING DEVICE AND DRIVING METHOD THEREOF - In a light emitting device, luminance irregularities caused by fluctuation in threshold of TFTs for supplying a current to EL elements among pixels hinder the light emitting device from improving the image quality. A voltage equal to the threshold of a TFT 03-07-2013
20120223651ILLUMINATION SYSTEM - An illumination system includes a lighting apparatus having a solid-state light emitting element as a light source; and a dimmer including a bidirectional switching element having a self-sustaining function and connected to a serial circuit of the lighting apparatus and an external power source. The dimmer varies a conduction angle of the bidirectional switching element by controlling a phase of an AC voltage of the external power source, wherein the lighting apparatus performs dimming of the light source based on the conduction angle of the bidirectional switching element, and the dimmer continues to apply driving current to the bidirectional switching element during a first period, which is a part of a second period, the bidirectional switching element being allowed to conduct throughout the second period.09-06-2012
20110012522FIXED FREQUENCY DIMMING METHOD AND FIXED FREQUENCY DIMMING CIRCUIT FOR LIGHT EMITTING MODULE - A fixed frequency dimming method and fixed frequency dimming circuit for a light emitting module can control light emitting brightness of the light emitting module through a hysteresis control circuit. A voltage difference between an upper limit voltage and a lower limit voltage of a hysteresis width of the hysteresis control circuit is maintained at a fixed value, and a driving current flowing through the light emitting module is changed by changing the upper limit voltage or the lower limit voltage.01-20-2011
20090302775MULTI-LAMPS INSTANT START ELECTRONIC BALLAST - The electronic ballast comprises a series half bridge resonant inverter and a control circuit for the inverter with dimming capability. The inverter includes a first and a second voltage feedback circuits including first and a second charge pumps coupled in between inverter output and the dimming input of the control circuit. The feedback circuits generate a reference control signal to control operation after starting and an error control signals when the inverter output voltage exceeds a predetermined value.12-10-2009
20120229045CONTROL CIRCUIT OF SWITCHING POWER SUPPLY FOR DRIVING LIGHT EMITTING ELEMENTS, AND LIGHT EMITTING DEVICE AND ELECTRONIC APPARATUS USING THE SAME - A control circuit of a switching power supply for supplying a drive voltage to a light emitting element is provided. The control circuit includes a pulse width modulator which generates a pulse signal whose duty ratio is adjusted such that a detection voltage corresponding to an output voltage of the switching power supply is equal to a predetermined reference voltage, a driver which drives a switching element of the switching power supply based on the pulse signal, and a standby control unit which stops driving of the switching element once a predetermined time has passed after a standby signal steps down to a level indicating a standby state, and to shut down the control circuit and a current source.09-13-2012
20120235591Dimmer Switch With Adjustable High-End Trim - A dimmer switch has a user adjustable high-end trim. The dimmer switch includes a bidirectional semiconductor switch, such as a triac, for controlling the amount of power delivered from a source of alternating current power to a lighting load, such as an electric lamp. A user-adjustable timing circuit controls the conduction time of the triac from a minimum time to a maximum time. The maximum possible conduction time of the triac is the high-end trim. The minimum possible conduction time of the triac is the low-end trim. The timing circuit includes a user-accessible switch that allows a user to reduce the high-end trim from a first nominal level to a second reduced level, lower than the first level, without substantially affecting the low-end trim. The switch allows a user to switch a transient voltage suppressor into and out of parallel connection with a resistor that is part of an RC timing circuit for the triac. The dimmer switch advantageously uses less energy and the lifetime of the lamp is extended when the second reduced level of the high-end trim is selected.09-20-2012
20130162162LED LIGHT SOURCE WITH MULTIPLE INDEPENDENT CONTROL INPUTS AND INTEROPERABILITY - An LED lighting control system incorporating a control IC for fast control of LED current in a switching Buck-type power supply through dedicated power supply control hardware with slow changing signals of temperature and input under control of firmware. The control IC optimizes the use of power from the source and optimizes the operating efficiency of the LED output while providing for a plurality of LED devices to be powered in parallel by a single controller.06-27-2013
20130162163ELECTRICAL POWER CONVERSION DEVICE AND LIGHTING DEVICE - According to one embodiment, a power conversion device includes a DC conversion circuit, an output conversion circuit, and a control circuit. The DC conversion circuit converts an external power supply voltage to a DC voltage. The output conversion circuit includes a switching element which converts a DC voltage which is converted in the DC conversion circuit to an output voltage corresponding to a load, and supplies the output voltage to the load. The control circuit controls an ON time of the switching element to be constant, regardless of a value of the output voltage corresponding to the load, which is output from the output conversion circuit.06-27-2013
20130162164PWM DRIVING CIRCUIT AND PWM DRIVING METHOD - Provided is a PWM driving circuit and a PWM driving method. The PWM driving circuit includes a dimmer switching unit turning on a first switch to apply a first reference signal varied according to an input voltage of a system when an output voltage level of a dimmer is a reference level or less, and turning on a second switch to apply a second reference signal, unrelated to the input voltage of the system, when the output voltage level of the dimmer is more than the reference level, an error amplification unit comparing the first reference signal or the second reference signal with an output detection signal to amplify an error and outputting an error amplification signal, and a PWM control signal generating unit comparing the error amplification signal of the error amplification unit with a predetermined reference waveform to output a PWM control signal.06-27-2013
20130162165LED DRIVER AND METHOD OF CONTROLLING AN LED ASSEMBLY - An LED driver for powering an LED fixture is described, the LED driver including a switched mode power supply for providing a current to the LED fixture, and a control unit for controlling a switch of the switched mode power supply. The control unit includes an input terminal for receiving a set point representing a desired output characteristic of the LED fixture. The control unit is further configured to periodically determine an opening instance of the switch and a closing instance of the switch, determining an average current estimate based on at least one measurement of the current to the LED fixture at least one measurement instance determined on the basis of at least one of the opening instance or the closing instance of the switch, and applying the average current estimate as a feedback signal representing the average current for controlling the LED current.06-27-2013
20100134030DRIVER APPARATUS FOR A GAS DISCHARGE LAMP - A driver apparatus (06-03-2010
20110095693FLUORESCENT LAMP BALLAST WITH ELECTRONIC PREHEAT CIRCUIT - Fluorescent lamp ballasts and methods are disclosed in which a resonant impedance of a self-oscillating inverter is modified to control the inverter frequency to selectively preheat lamp cathodes using power from the inverter output during a preheating period after power is applied and to change the inverter frequency to a different range following ignition of the lamp.04-28-2011
20100213859Adaptive Current Regulation for Solid State Lighting - Exemplary embodiments provide an apparatus, system and method for power conversion to provide power to solid state lighting, and which may be coupled to a first switch, such as a dimmer switch. An exemplary system for power conversion comprises: a switching power supply comprising a second, power switch; solid state lighting coupled to the switching power supply; a voltage sensor; a current sensor; a memory; a first adaptive interface circuit to provide a resistive impedance to the first switch and conduct current from the first switch in a default mode; a second adaptive interface circuit to create a resonant process when the first switch turns on; and a controller to modulate the second adaptive interface circuit when the first switch turns on to provide a current path during the resonant process of the switching power supply.08-26-2010
20110298386LED LIGHTING FIXTURE WITH ONE SET OF INTENSITY OF LIGHT - A LED lighting apparatus includes at least one LED lighting element, a control unit and a switching converter, for supplying the LED lighting element. A feedback circuit is connected between the LED lighting element and a ground line and co-operates with the switching converter for determining a LED current through LED lighting element. The feedback circuit has a first impedance in a first state, to which a non-zero first regulation value of the LED current corresponds, and a second impedance in a second state, to which a non-zero second regulation value of the LED current corresponds. The control unit is configured to cyclically switch the feedback circuit between the first state and the second state with a controllable duty-cycle.12-08-2011
20110291578TEMPERATURE COMPENSATED DRIVER FOR PULSED DIODE LIGHT SOURCE - A pulsed diode light source driver includes a variable output power supply, an output capacitor, a switchable linear current driver, a temperature sensor, a conditioning circuit, and a voltage monitor. The temperature sensor monitors the temperature of the capacitor while the voltage monitor circuit monitors the output voltage level. The conditioning circuit and the voltage monitor cooperatively control the output voltage of the variable output power supply, so that temperature-related changes in the characteristics of the capacitor are compensated for, and a constant current is maintained through the diode load over a desired range of temperature. The driver is suitable for laser diodes and light emitting diodes.12-01-2011
20110291577Dimmer Conduction Angle Detection Circuit and System Incorporating the Same - A dimmer conduction angle detection circuit, and systems and methods incorporating the same, is disclosed. The circuit receives a gate drive signal from a PFC circuit and provides a dimmer reference level signal representative of a dimmer circuit's dimmer setting in response. The circuit includes a comparator with first and second inputs that provides a pulse-width modulated output in response to comparing signals received at the inputs. The pulse-width modulated output has a pulse width representative of the dimmer circuit's dimmer setting. The circuit also includes an input network, coupled to the comparator, to receive the gate drive signal and to provide an output, in response, to the comparator's first input. The circuit also includes a threshold supply circuit to provide a threshold voltage to the comparator's second input, and a filter, coupled to the comparator, to convert the comparator's pulse-width modulated output to the dimmer reference level signal.12-01-2011
20100033101Electronic Ballast with Multimode Lamp Power Control - A control means has an adjustment function in a microprocessor to adjust variations in an output to a discharge lamp due to variations in components by correcting a duty ratio of a PWM signal for varying an operating frequency of an inverter circuit so that a detected value of a second detection circuit falls within a target range. The microprocessor switches paths to transmit the PWM signal between a path passing through a feedback circuit and a path passing through a voltage follower circuit by switches a switch circuit to supply the signal through the path passing through the voltage follower circuit in adjusting output variations in the preheating mode and the starting mode.02-11-2010
20110215729METHOD FOR OPERATING A FLUORESCENT LAMP - A method for operating a fluorescent lamp which is connected to a series resonant circuit with a resonant circuit inductance and a resonant circuit capacitance. The method includes applying an excitation AC voltage at an excitation frequency to the series resonant circuit using a half bridge circuit, which has an output to which the series resonant circuit is coupled, and which has a first and a second switch which are alternately switched on and off on the basis of a frequency signal. A current flowing through the resonant circuit is monitored for the presence of a critical operating state. The switched-on times of the first and second switches are shortened in comparison to switched-on times which are predetermined by the frequency signal, upon detection of a critical operating state.09-08-2011
20120187858LOAD DRIVING DEVICE AND ELECTRONIC DEVICE USING THE SAME - A load driving device includes a switch element configured to generate an output voltage to a load from an input voltage depending on an ON/OFF operation thereof, a switch controller configured to control the ON/OFF operation of the switch element such that a feedback voltage obtained by subtracting a dropped voltage of the load from the output voltage and a predetermined reference voltage are maintained to be consistent, and a variable current source configured to perform ON/OFF controlling of a driving current flowing to the load in response to a driving current control signal. When the switch element is in an ON state at an OFF timing of the driving current, the switch controller maintains the switch element in the ON state thereafter, and turns off the switch element when the ON period of the switch element reaches a predetermined period.07-26-2012
20120187857LIGHTING SYSTEM, ELECTRONIC DEVICE FOR A LIGHTING SYSTEM AND METHOD FOR OPERATING THE ELECTRONIC DEVICE - An electronic device for a lighting system, comprising a TRIAC dimmer configured to receive a mains supply voltage and provide a phase cut voltage to the electronic device and having a control loop configured to control a duty cycle of a switched voltage converter that receives the rectified input voltage and provides drive current to a light emitting semiconductor device. The control loop has an error amplifier that is coupled to receive a sense voltage that is indicative of a current through the light emitting semiconductor device, the error amplifier is configured to provide a feedback signal to a pulse width modulation logic configured to control the duty cycle of the switched voltage converter to provide a constant drive current to the light emitting semiconductor device in response to the sense voltage, the error amplifier being coupled to receive a reference voltage that is a function of the input voltage.07-26-2012
20090146574Safety circuit for electro-luminescent lamp ballast - A safety circuit is provided for a ballast of an electro-luminescent (EL) lamp. The EL lamp had an electrical ground shield on at least a portion thereof and has a separate ground lead. The ballast is an isolated ballast with a line input being isolated from an output. The ballast is constructed and arranged to be electrically connected with the separate ground lead. The circuit includes a current sensing structure constructed and arranged to connect between the separate ground lead and a potential ground of the ballast. In the event a user contacts the EL lamp to replace the EL lamp or contacts a defective EL lamp, the ballast is shut down based on a value of current sensed by the current sensing structure.06-11-2009
20100264839LOAD CONTROL DEVICE, AND LIGHTING DEVICE - Provided is a discharge lamp lighting device, which can control a load precisely while improving the practicability. When the difference of a count number (Nn) becomes a predetermined threshold value or less, a predictor circuit (10-21-2010
20080265791BACKLIGHT MODULE AND CURRENT PROVIDING CIRCUIT THEREOF - A backlight module and a current providing circuit thereof are provided. The current providing circuit includes a signal generating unit, a switching unit, a first capacitor, a transformer and an output node. The signal generating unit generates a PWM signal according to a level of a power source. The switching unit determines whether a first signal end and a second signal end of the switching unit are conducted according to the PWM signal received by a control end of the switching unit. Following a switch performed by the switching unit, the first capacitor charges and discharges through a current path provided by a primary coil of the transformer. Thereby, a secondary coil of the transformer generates a corresponding AC voltage by sensing a current change in the primary coil and outputs the AC voltage through the output node.10-30-2008
20080265792Constant Brightness Control For Electro-Luminescent Lamp - A ballast (10-30-2008
20100084986CIRCUIT ARRANGEMENT AND METHOD FOR PROGRESSIVELY DIMMING ONE OR MORE LIGHTING MEANS - Various embodiments provide a circuit arrangement with two or more switching inputs for progressively dimming one or more lighting means, the switching inputs being capable of being current-conducting or non-current-conducting, wherein the circuit arrangement is configured such that it, owing to the switching combination of the switching inputs, provides a dimming signal at the output, which dimming signal can be processed by the operating devices connected thereto and dims the lighting means to corresponding light levels.04-08-2010
20100079077AC Delay Angle Control for Energizing a Lamp - A control circuit for a lamp. The control circuit is used in conjunction with an alternating current (AC) variable voltage power source to energize the lamp. The control circuit includes a voltage sensing component for sensing the voltage of an voltage input signal from the power source for energizing the lamp. The control circuit includes a controller configured to estimate a delay angle as a linear function of the sensed voltage. The control circuit includes an AC converter for modifying the voltage input signal according to the estimated delay angle to generate an AC voltage output signal having a constant root mean square voltage for energizing the lamp.04-01-2010
20090206763METHOD AND APPARATUS FOR CONTROLLING A DISCHARGE LAMP IN A BACKLIGHTED DISPLAY - The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.08-20-2009
20100123405FEEDBACK CIRCUIT FOR DC/AC INVERTER - A feedback circuit is utilized in a DC/AC inverter having a first power switch and a second power switch for driving a fluorescent lamp. The feedback circuit includes a protection circuit for disabling the first power switch and the second power switch when no fluorescent lamp is electrically connected, a first capacitor having a first terminal electrically connected to an output of the DC/AC inverter, a second capacitor having a first terminal electrically connected to a ground, and a second terminal electrically connected to a second terminal of the first capacitor, a diode having an anode electrically connected to the second terminals of the first and second capacitors, and a cathode electrically connected to the protection circuit, and a first resistor having a first terminal electrically connected to the cathode of the diode, and a second terminal electrically connected to the ground.05-20-2010
20080211419Method and apparatus for driving a light emitting diode - An apparatus includes circuitry that responds to application to its input of an alternating current input signal by producing at its output an output signal suitable for driving an electronic light generating element. The circuitry includes a regulating section that has a magnetic switch and that causes a current flowing through the output to be maintained substantially at a selected value. A different aspect relates to a method for operating circuitry having an input, an output and a magnetic switch. The method includes causing the circuitry to respond to application to its input of an alternating current input signal by producing at its output an output signal suitable for driving an electronic light generating element, where the magnetic switch is used in regulating a current flowing through the output so as to maintain the current substantially at a selected value.09-04-2008
20090289563Circuit Arrangement and Method for Operating At Least One Dielectric Barrier Discharge Lamp - The invention relates to a circuit assembly for operating at least one dielectrically impeded discharge lamp (La11-26-2009
20080315782Discharge lamp lighting apparatus and projector - A discharge lamp lighting apparatus for turning on a discharge lamp has a lighting condition in which a projection is formed at a tip of an electrode for electric discharge. In the discharge lamp lighting apparatus, when the polarity-reversal mode is the second mode, the inverter control circuit operates to generate the inverter control signal so that a DC component contained in the output current increases more than that in the first mode, when the polarity-reversal mode is the first mode, and it is detected that the lamp voltage is lower than a predetermined first voltage, the polarity-reversal mode control circuit changes the polarity-reversal mode into the second mode, and when the polarity-reversal mode is the second mode, and it is detected that the lamp voltage is higher than a predetermined second voltage, the polarity-reversal mode control circuit changes the polarity-reversal mode into the first mode.12-25-2008
20090289565AGGREGATE IGNITION METHOD IN HIGH FREQUENCY METAL HALIDE LAMPS - A high frequency ballast for a metal halide lamp comprises a controller, a switch, and an oscillator. The controller selectively enables and disables the oscillator via the switch to ignite the lamp. The ignition method includes enabling the oscillator such that the oscillator provides the lamp with a pulse train comprising a rapid series of short ignition pulses, cools for a period of time, and provides an addition pulse train to the lamp if necessary to ignite the lamp. When the lamp ignites, the ballast maintains enablement of the oscillator.11-26-2009
20090289564CERAMIC METAL HALIDE LAMP BI-MODAL POWER REGULATION CONTROL - A high frequency ballast for a metal halide lamp comprises a controller, a switch, and an oscillator. The controller selectively enables and disables the oscillator via the switch to ignite the lamp. The switch selectively alters an inductance of the inductor to switch between a first frequency of the oscillator and a second frequency of the oscillator different than the first. The controller monitors a current of a power supply loop of the oscillator and a voltage of the oscillator and determines a duty cycle as a function of the monitored voltage and current. The duty cycle is indicative of the percentage of time that the oscillator is to operate at the first frequency versus the second frequency.11-26-2009
20090295301Self-exciting step-up converter - An electronic ballast includes a step-up converter, which includes a storage inductor, a diode, an intermediate circuit condenser and a switch element. According to the invention, a current passing through the storage inductor is used in the form of an indicator of turnon and turnoff times of the step-up converter oscillates in a self-exciting manner.12-03-2009
20130099693CIRCUIT FOR FLASH LAMP - A circuit for a gas discharge system includes a pulse forming circuit, a discharge lamp, a circuit for recovering energy from the discharge lamp when a trigger to the lamp is turned off, a high voltage switch between the lamp and ground, and a two-part dissipating circuit across the switch. The system can provide a flat response with highly controllable pulse width.04-25-2013
20130099694LIGHTING DEVICE AND LIGHTING FIXTURE USING THE SAME - The lighting device in accordance with the present invention includes: a switching regulator including a switching element and an inductor and configured to supply a direct current to a DC light source; a control circuit unit for controlling the switching element in accordance with a dimming signal for determining an on period in which the DC light source is kept turned on and an off period in which the DC light source is kept turned off to adjust luminance of the DC light source; a current detection unit configured to output a detection value indicative of a current flowing through the inductor; and a superimposing circuit unit. The circuit control unit, in the on period, turns off the switching element when an input value received via the input terminal for receiving the detection value exceeds a first threshold, and turns on the switching element when the input value falls below a second threshold, and keeps turning off the switching element in the off period. The superimposing circuit unit is configured to keep the input value not less than the second threshold in the off period.04-25-2013
20080278086Electronic ballast having a boost converter with an improved range of output power - A boost converter for an electronic dimming ballast for driving a gas discharge lamp has an increased output power range. The boost converter operates in discontinuous conduction mode when a desired intensity of the lamp is below a first threshold intensity, and operates in critical conduction mode when the desired intensity is above a second threshold intensity. The boost converter comprises a delay circuit for introducing an amount of delay into the conduction of current through the boost converter. A control circuit of the ballast is operable to drive the delay circuit and thus control the operation of the boost converter in response to the desired intensity of the lamp. The control circuit is further operable to drive the delay circuit with a pulse-width modulated signal to provide multiple amounts of delay into the operation of the boost converter.11-13-2008
20080284346LIGHT EMITTING DIODE ARRAY DRIVING APPARATUS - There is provided a LED array driving apparatus for driving a light emitting array having a plurality of LEDs connected to one another, including: a DC-DC converting part; a current/voltage detecting part detecting a magnitude of a first current flowing through a switching transistor of the DC-DC current converting part to correspondingly output a first current detection voltage, detecting a magnitude of a both-end voltage of the LED array to correspondingly output a LED array detection voltage, and detecting a magnitude of a current flowing through the LED array to correspondingly output a second current detection voltage; and a constant current controlling part controlling an on/off duty of the switching transistor according to the magnitude of the first current detection voltage, the second current detection voltage and the LED array detection voltage detected by the current/voltage detecting part.11-20-2008
20080303449COLD CATHODE FLUORESCENT LIGHTING DISCHARGE TUBE DEVICE - A cold cathode fluorescent lighting discharge tube device is provided which comprises a first ballast element 12-11-2008
20120293089DEVICE FOR IGNITION AND OPERATING DISCHARGE TUBES BY USING ENERGY IMPULSE AND RESONANCE CIRCUIT - The invention relates to a device for ignition and operation of discharge tubes in an energy saving mode and using a bridge-coupled DC/AC converter. The discharge tube is connected to the AC output of the bridge-coupled device. The essence of the invention lies in that the condenser (11-22-2012
20080309246Projector Device Employing Ballast with Flyback Converter - A projector device employing ballast with a flyback converter is disclosed. For example, one embodiment comprises a lamp driver circuit including a power stage circuit including a flyback converter to output a direct current signal to a bridge circuit, the bridge circuit to reconstruct the direct current signal to an alternating current signal, a control circuit coupled with the power stage circuit and the bridge circuit, the control circuit to receive the direct current signal from the power stage circuit and to provide a frequency control signal to the bridge circuit, and a lamp igniter circuit comprising at least one charge pump and being coupled with the bridge circuit, wherein in response to the frequency control signal being provided to the bridge circuit, the bridge circuit is configured to increase the voltage of the alternating current signal provided to the lamp igniter circuit to power the lamp igniter circuit.12-18-2008
20090033236Programmed ballast with resonant inverter and method for discharge lamps - A ballast having a rapid inverter frequency control circuit that is used for programmed operation during lamps starting, during normal operation of all lamps and during no lamp(s) operation. A method and circuit controls frequency shift via a combination of different feedback circuits. A control signal for the inverter controller is synthesized as a sum of phase shifted inverter output voltage feedback signal and lamp current sense signal indicating status of each lamp connected to the ballast output.02-05-2009
20110204806CIRCUIT ARRANGEMENT FOR OPERATING A DISCHARGE LAMP - An apparatus for operating a gas discharge lamp. The apparatus includes an electronic ballast and a controller. The electronic ballast includes a half bridge configuration, a full bridge configuration, a first network, and a second network. The electronic ballast is controlled by a controller that causes the half bridge configuration to ignite an arc between electrodes of the gas discharge lamp in an igniter function that uses the first network, to switch the electronic ballast from the half bridge configuration to the full bridge configuration after the arc is ignited so that a buck inverter function using the second network sustains the arc between the electrodes of the gas discharge lamp, and to provide a transient operation function to the buck inverter function to produce a spike voltage that is used to re-ignite the arc between the electrodes of the gas discharge lamp when the arc extinguishes.08-25-2011
20100127630LAMP LIGHTING DEVICE AND PROJECTOR TYPE PICTURE DISPLAY DEVICE USING SAME - Lamp lighting device serves to light up a selected one of two high pressure mercury lamps, and includes a starting pulse generating circuit for outputting a starting pulse voltage; two step-up transformers having secondary windings connected to trigger windings of the lamps respectively; an inverter for outputting an alternating-current voltage; and relays each for providing the starting pulse voltage to a primary winding of a step-up transformer corresponding to the selected lamp, and each for providing the alternating-current voltage to main electrodes of the selected lamp. Since the step-up transformers are provided at stages coming after the relays as such, relays with low breakdown voltage can be used.05-27-2010
20080278085Program Start Ballast - A ballast (11-13-2008
20080309245SYSTEM AND METHOD FOR ANALOG VOLTAGE PROCESSING IN WIDE RANGE FOR COLD-CATHODE FLUORESCENT LAMP - System and method for processing analog voltage for cold-cathode fluorescent lamp. The system includes a voltage-to-current converter configured to receive an input analog voltage signal and generate a first current signal, and a current processing component configured to receive the first current signal and a predetermined current and generate a second current signal. Additionally, the system includes a current-to-voltage converter configured to receive the second current signal and generate an output analog voltage signal, and a dimming controller configured to receive the output analog voltage signal and generate a control signal for driving at least a cold-cathode fluorescent lamp. The voltage-to-current converter, the current processing component, and the current-to-voltage converter are configured to be biased between a first power supply voltage level and a second power supply voltage level.12-18-2008
20080272709THREE-WAY DIMMING BALLAST CIRCUIT - A three-way dimming ballast circuit for driving a ballast power switching circuit powering a gas discharge lamp such as a CFL. The circuit includes a driver circuit for driving high and low side switches of the ballast power switching circuit; a control circuit for driving the driver circuit including an oscillator circuit for providing an oscillating signal to control the frequency of operation of the ballast power switching circuit, the ballast power switching circuit outputting lamp-powering pulsed signals; and a dimming control circuit having an input, the dimming control circuit receiving an AC lamp current feedback signal at the input, the dimming control circuit further receiving a DC input voltage reference at the input, whereby the DC input voltage reference determines a desired dimming level of the lamp and the AC lamp current feedback signal maintains the lamp brightness at the desired dimming level. The DC input voltage reference is provided by one or both of a setting circuit comprising forward-biased diodes and/or an override circuit comprising transistors that are switched on to apply a maximum DC voltage.11-06-2008
20080290810DISCHARGE LAMP CONTROLS - At least one electric discharge lamp capable of generating a broadband output pulse of a range of wavelengths in the visible spectrum, the output pulse having a predetermined time interval and a predetermined total electrical energy input for the pulse, has a drive circuit for delivering energy pulses to the electrical discharge lamp, as well as a sensor for sensing an optical output from the discharge lamp; and a control mechanism for operating the drive circuit in response to variations in optical output detected by the sensor.11-27-2008
20080278087Pulse Width Modulation Apparatus and Apparatus for Driving Light Source Having the Same - Provided are a pulse width modulation (PWM) apparatus and a light source-driving apparatus including the PWM apparatus. The PWM apparatus includes a voltage division part, a capacitor part, a first operational amplifier, a first noise reduction part, and a second operational amplifier. The voltage division part divides and outputs an input voltage. The capacitor part charged by an input current or discharged for provides a charge voltage. The first operational amplifier operates according to a result of comparing a divided voltage output from the voltage division part with the charge voltage output from the capacitor part. The first noise reduction part removes a high frequency noise of the divided voltage. The second operational amplifier converts a signal generated from the capacitor part into a pulse width modulation signal by a dimming control signal.11-13-2008
20080272708Driving circuit for and semiconductor device for driving laser diode - A driving circuit supplies a suppression current (I11-06-2008
20080272707Lamp ballast circuit - In one embodiment, a power switch driving circuit is provided for a fluorescent lamp ballast. The circuit includes a first power switch driven by a first driver. A controller has a first output terminal for outputting a control signal for controlling the first driver. The first driver includes a first capacitor having a first terminal electrically connected to a control electrode of the first power switch and a second terminal electrically connected to the first output terminal.11-06-2008
20110006697LOW PIN COUNT LED DRIVER INTEGRATED CIRCUIT - A LED driver integrated circuit has a voltage input pin, a voltage output pin, a capacitor pin, and a switching circuit connected to the capacitor pin and the voltage output pin. The capacitor pin and the voltage output pin are for a flying capacitor to be connected therebetween, and thus the switching circuit and the flying capacitor establish a charge pump to convert an input voltage received by the voltage input pin into an output voltage at the voltage output pin.01-13-2011
20100270937CIRCUIT AND METHOD FOR STRIKING CCFL - A circuit for controlling the switch frequency of an inverter that strikes and drives fluorescent lamps is disclosed. The circuit comprises a frequency generator and an offset circuit. The offset circuit provides a current signal in response to the lamp status. The frequency generator provides a frequency control signal in respond to the current signal so as to control the switch frequency of the inverter. When the lamp is open, the switch frequency of the inverter is higher; when the lamp is lighted, the switch frequency of the inverter is lower.10-28-2010
20130214694METHOD AND CONTROL CIRCUIT FOR STARTING A GAS-DISCHARGE LAMP - A method operates a gas-discharge lamp (08-22-2013
20090160348Discharge lamp lighting device and projector - A method of generating a driving current supplied to a high pressure discharge lamp, including outputting a DC current, converting the DC current to an AC current having a predetermined frequency, generating a reference pulse which is asynchronous with the AC current, and superposing the first pulse and the second pulse to the AC current for producing the driving current.06-25-2009
20110221354Method and Circuit Arrangement for Making a Lamp Wattage Available for Operating at Least one Gas Discharge Lamp - A method for making a lamp wattage available for operating at least one gas discharge lamp depending on a dimming signal which is input into a wattage factor correction circuit, having a switch element that is switched on clocked by a switch-on time, wherein the wattage factor correction circuit emits an intermediate circuit voltage which in turn is input into a converter that makes the lamp wattage available, comprising the steps of: in an operating phase in which the dimming signal has no phase leading edge and no phase trailing edge, the wattage factor correction circuit and the converter are regulated independently of each other using a separate regulating circuit in each case; and in an operating phase in which the dimming signal has a phase leading edge or a phase trailing edge, the two independent regulating circuits are coupled to each other via a higher-order third regulating circuit such that the lamp wattage of the converter is adjusted such that the switch-on time of the switch element in the wattage factor correction circuit corresponds to a predetermined time.09-15-2011
20120104961LIGHTING DEVICE OF DISCHARGE LAMP AND METHOD OF CONTROLLING LIGHTING OF DISCHARGE LAMP - A lighting device of a discharge lamp, the lighting device includes: a DC voltage generating circuit including: a switching element that is controlled by a first controlling signal; and a coil that has one end portion, to which a first DC voltage is input, and the other end portion of the coil outputs a second DC voltage, and an AC voltage generating circuit that converts into an AC voltage and supplies to the discharge lamp; and a control circuit unit, which receives a polarity-inversion instructing signal, which generates a second controlling signal to determine a timing of polarity-inversion after a predetermined first period is elapsed, which sets a latest ON period, wherein the latest ON period is set based on both an elapsed time and the duty ratio, and which generates the first controlling signal to restart the ON/OFF control at a timing after a second period is elapsed.05-03-2012
20080315781DISCHARGE LAMP LIGHT-UP CONTROL APPARATUS AND POWER CIRCUIT - The present invention is directed to realize an optimum lamp control with an inexpensive configuration in a discharge lamp light-up control apparatus. A constant current control unit controls light-up of a discharge lamp by transmitting a control signal to an inverter and includes: a storage for storing lamp characteristics of the discharge lamp; and a CPU for obtaining information indicative of a type of the discharge lamp attached, reading the lamp characteristics from the storage based on the obtained type information, and transmitting a control signal to the inverter so that an output corresponding to the read lamp characteristics are obtained.12-25-2008
20110227497POWER SYSTEMS FOR DRIVING LIGHT EMITTING DIODES AND ASSOCIATED METHODS OF CONTROL - Embodiments of LED driver circuits and the associated methods are disclosed herein. In one embodiment, the LED driver circuit comprises a switch-mode converter, a controller, a feedback circuit, and a gating circuit. The feedback circuit includes a current balance circuit. The gating circuit is responsive to both a current feedback signal and a voltage feedback signal and is configured to select one of them as the feedback signal.09-22-2011
20090108765TWO-WIRE DIMMER CIRCUIT FOR A SCREW-IN COMPACT FLUORESCENT LAMP - A dimmer switch for controlling the intensity of a dimmable screw-in compact fluorescent lamp provides smooth dimming of the fluorescent lamp and prevents flickering of the lamp due to multiple re-strikes. The dimmer switch prevents multiple re-strikes by avoiding multiple firings of a controllably conductive switching device of the dimmer circuit by limiting the high-end light intensity of the fluorescent lamp. Specifically, the dimmer switch limits the length of a conduction interval of the controllably conductive switching device to less than approximately 75% of each half-cycle. The dimmer switch may include a user-accessible adjustment actuator for changing the dimmer switch between an incandescent operating mode and a screw-in compact fluorescent mode. The dimmer switch may also be operable to automatically change the dimmer switch between the incandescent operating mode and the screw-in compact fluorescent mode by detecting the occurrence of the multiple firings of the controllably conductive switching device.04-30-2009
20090315470HIGH-PRESSURE DISCHARGE LAMP LIGHTING DEVICE AND LIGHTING FIXTURE USING THE SAME - A high-pressure discharge lamp lighting device includes: a power converter circuit which includes a plurality of switching elements and an inductance element, converts an input from a DC power supply, and supplies a rectangular wave AC output to a high-pressure discharge lamp; and a control circuit which controls the switching elements of the power converter circuit. The control circuit performs first lighting control in which the switching elements of the power converter circuit are controlled in order to supply a current to a peak value for each switching cycle, and performs second lighting control in which desired power is supplied during steadily lighting state of the high-pressure discharge lamp; and the first lighting control and the second lighting control are switched over in response to a lighting state of the high-pressure discharge lamp.12-24-2009
20110140621CIRCUITS AND METHODS FOR CONTROLLING A LIGHT SOURCE - A driving circuit for controlling a light source includes a frequency controller and a switch module. The frequency controller is operable for receiving a first dimming signal for controlling the light source to achieve a predetermined brightness, and for generating a second dimming signal having a frequency out of one or more predetermined ranges according to the first dimming signal when the frequency of the first dimming signal is within the predetermined ranges. The switch module coupled to the frequency controller is operable for switching on and off alternately to achieve the predetermined brightness of the light source according to the second dimming signal when the frequency of the first dimming signal is within the predetermined ranges and according to the first dimming signal when the frequency of the first dimming signal is out of the predetermined ranges.06-16-2011
20110140622LED DRIVING CIRCUIT - An LED driving circuit includes a dimming circuit that controls a conducting angle of an alternating current supplied from a power supply to phase-control a current to be supplied to an LED, a rectifier circuit that rectifies an alternating-current voltage output from the dimming circuit, a smoothing circuit that smoothes a direct current voltage output from the rectifier circuit, a switching device that is connected with the LED in series; a constant current control circuit that outputs a high frequency pulse signal to the switching device to control the switching device, and a bleeder circuit that is provided between an output terminal of the rectifier circuit and a ground and that has a bleeder resistance and a bleeder switch connected in series. The high frequency pulse signal is input to the bleeder switch so that a bleeder current having a high frequency pulse form flows in the bleeder resistance.06-16-2011
20100156308ADJUSTABLE OUTPUT BALLAST FOR POWERING BOTH FLUORESCENT LAMPS AND LED LAMPS - A ballast is provided for powering either of a fluorescent lamp or an LED lamp. The ballast includes a power supply and a pair of switching elements connected in series and coupled across an output end of the power supply. A voltage is provided across a pair of lamp output terminals coupled to the switching elements during a predetermined time period after startup of the ballast. A current condition is detected across the pair of lamp output terminals during the predetermined time period. Based on the detected current condition, the presence of a fluorescent lamp or an LED lamp connected to the ballast may be determined, and either of a first or second voltage output is provided across the lamp output terminals suitable for powering the appropriate lamp after lapsing of the predetermined time period.06-24-2010
20110140620CIRCUITS AND METHODS FOR CONTROLLING DIMMING OF A LIGHT SOURCE - A controller for controlling dimming of a light source includes a detection pin, an input signal pin, and a monitoring pin. The detection pin is operable for monitoring a rectified voltage and for detecting whether the rectified voltage comes from a TRIAC dimmer or an on/off switch dimmer. The input signal pin is operable for receiving an input signal indicative of the rectified voltage and the controller controls dimming of the light source according to the input signal if the rectified voltage comes from a TRIAC dimmer. The monitoring pin is operable for receiving a monitoring signal indicating an operation of the on/off switch dimmer and the controller controls dimming of the light source according to the monitoring signal if the rectified voltage comes from an on/off switch dimmer.06-16-2011
20100148684SUPPLY DEVICE OF CIRCUIT BRANCHES WITH LED DIODES - A device includes at least two circuit branches, each of said at least two circuit branches comprising at least one LED diode. The device comprises a supply circuit that provides an electric supply of said at least two circuit branches and includes a variable resistance. The device comprises a controller coupled to said at least two circuit branches and suitable for varying said resistance in reply to a variation of the current that flows in one of said at least two circuit branches to vary the electric supply of said at least two circuit branches.06-17-2010
20100188008Lighting Controllers - This invention generally relates to lighting controller, more particularly to electronic ballast circuits, sometimes referred to as electronic control gears (ECG) or gas discharge lamps.07-29-2010
20100194303ELECTRONIC BALLAST FOR CORRECTING ASYMMETRICAL CURRENT FLOW ACROSS A GAS DISCHARGE LAMP - An electronic ballast for powering a discharge lamp includes an asymmetry determination circuit functional to determine whether positive and negative polarities of an AC output current to the lamp are symmetrical. An inverter having a plurality of switching elements is coupled to a DC power source and converts the DC power to the AC output current. A control circuit is functional to control the plurality of switching elements dependent upon an operating mode and an output from the asymmetry determination circuit. The control circuit controls the switching elements in a normal mode upon receiving a determination of symmetrical current from the asymmetry determination circuit, and controls the switching elements in a restart mode for a predetermined period of time upon receiving a determination of asymmetrical current from the asymmetry determination circuit.08-05-2010
20100188006Dimming alternating current light emitting diodes - The disclosed invention directs the current path of the light source through a signal rectifier and series switch, which is controlled by the pulse width modulation (PWM) generator based on the input intensity level. The direct current series switch (i.e. MOSFET) does not require a minimum current level, or “holding current”, to respond correctly to the control signal. The modulated control signal continues over the entire cycle period, which ensures accurate duty cycle control regardless of the minimum forward voltage bias, or “turn on voltage”, of the light source. In addition, accurate duty cycle control allows the possibility of non-linear dimming curves to compensate for human factors or characteristics of the light source. The high frequency (i.e. >2 kHz) of the modulation results in the users perception of consistent intensity and smooth transitions. The disclosed invention addresses the principle issues associated with dimming AC LED technology, while maintaining compatibility with traditional incandescent sources, by providing accurate duty cycle control independent of I-V characteristics of the light source and not requiring a “holding current”. The disclosed invention can adjust the intensity of any LED device that reacts to a significant portion of the ON and OFF time periods created by the modulation of the input power.07-29-2010
20100259180LED CIRCUIT AND METHOD FOR CONTROLLING THE AVERAGE CURRENT OF THE LED - An LED circuit is disclosed. The circuit senses the average current flowing through the LED. The sensed signal is compensated and modulated. The modulated signal is then used to control the ON/OFF state of a switch that supplies power to the LED.10-14-2010
20130214695Dimming Driver With Stealer Switch - A dimming driver with stealer switch.08-22-2013
20100225239METHODS AND APPARATUS FOR A HIGH POWER FACTOR, HIGH EFFICIENCY, DIMMABLE, RAPID STARTING COLD CATHODE LIGHTING BALLAST - Methods and apparatus for powering a dimmable ballast operating a gas-discharge bulb in a cold cathode mode of operation, that is, without requiring heating of filaments. The ballast circuit includes a rectifier, bypass capacitor, driver circuit, and a tank circuit that includes a resonant circuit that are configured to ionize a light source, such as a fluorescent lamp, every half cycle of the input voltage. The bypass capacitor supplies energy to produce a high frequency current introduced into the resonant circuit to continually recycle energy in the resonant circuit, resulting in a ballast with a high power factor. A tank circuit comprising a tapped inductor operating in a non-saturated or limited saturated mode provides additional voltage to the bulb to ionize the bulb. The ballast may be dimmed and combined with other energy savings circuitry.09-09-2010
20100207536HIGH EFFICIENCY LIGHT SOURCE WITH INTEGRATED BALLAST - The present invention relates to regulated power supplies or ballasts integrated with an LED light source. The invention provides a power factor correction scheme producing a greater circuit power factor and improved frequency spectrum characteristics, in which a voltage corresponding to the instantaneous inductor current is sampled and compared to a scaled sample of the rectified input AC line voltage. The line voltage sample modulates the inductor peak charge current in the envelope of the rectified AC voltage waveform. This drives the LED output voltage at a frequency of twice the input line voltage frequency, such that no flicker is perceived in the light output because the persistence in LED phosphor assists in averaging the flux output.08-19-2010
20100156307POWER SUPPLY FOR LIGHT EMITTING DIODE DISPLAY - There is provided a power supply for a light emitting diode display using a light emitting diode as a backlight unit that unites a DC power supply provided from outside the light emitting diode display and a driving power supply provided inside the light emitting diode display. A power supply of a light emitting diode display according to an aspect of the invention may include: a power conversion unit converting commercial AC power into at least one driving power having a predetermined voltage level; and a backlight driving unit generating a backlight driving signal using the driving power from the power conversion unit, wherein the power conversion unit and the backlight driving unit are mounted onto one printed circuit board.06-24-2010
20100237794DISCHARGE LAMP BALLAST WITH FEEDBACK CURRENT CONTROL DURING AN ELECTRODE HEATING OPERATION - A discharge lamp ballast is provided with a feedback control operation to provide optimal lamp current flow during an electrode heating operation. A startup circuit coupled together with a discharge lamp between output terminals of a DC-AC power converter having a plurality of switches. The startup circuit generates a high voltage to ignite the lamp. A lamp current sensor detects an amplitude of an output current to the lamp. A control circuit controls the switches in accordance with each of a plurality of control operations including a startup operation to ignite the lamp using the high voltage generated by the startup circuit, an electrode heating operation wherein an operating frequency of the switches is controlled to set the amplitude of the detected output current to a predetermined target current amplitude, and a normal operation wherein the operating frequency is reduced to maintain stable lighting of the lamp.09-23-2010
20120139435Method for Controlling a Voltage Transformer for Overvoltage Protection, Voltage Transformer and Operating Device having a Voltage Transformer - A method for controlling a voltage transformer for operating a switchable load having at least one inductance and a switch, which is activated by a digital control device. When the switch is closed, a magnetizing current flows through the inductance. When the switch is open, a demagnetizing current flows through the inductance. The method comprises the steps of measuring the demagnetizing time of the inductance and, when a maximum value of the demagnetizing time of the inductance is exceeded, storing such an ocurrence as a fault. The load is disconnected by the control device when a predetermined maximum frequency of faults is exceeded.06-07-2012
20100219765LIGHTING APPARATUS FOR HIGH-VOLTAGE DISCHARGE LAMP - In a lighting apparatus for a high-voltage discharge lamp, a control circuit controls a switching element of a step-down chopper circuit and that of an igniter circuit such that the switching elements are synchronously turned on/off, and controls the switching of the switching element of the step-down chopper circuit in accordance with an amount of a drop in the output voltage of the step-down chopper circuit when lighting of a high-voltage discharge lamp is started such that inrush current flowing when the high-voltage discharge lamp breaks down is suppressed. With this, when a lighting apparatus starts lighting the high-voltage discharge lamp, the inrush current flowing when the lamp breaks down can be minimized in response to variations in the load of the high-voltage discharge lamp. In addition, the lifetime of the high-voltage discharge lamp can be increased since inrush current during glow discharge can be suppressed.09-02-2010
20100219766CIRCUITS AND METHODS FOR DRIVING LIGHT SOURCES - A dimming controller for controlling power of a light source has a monitoring terminal, a dimming terminal, and a control terminal. The monitoring terminal is operable for receiving a current monitoring signal indicating a current flowing through the light source. The dimming terminal is operable for receiving a ramp signal. The voltage of the ramp signal increases if a power switch coupled between a power source and the light source is turned on. The control terminal is operable for providing a control signal to control a control switch coupled in series with the light source based on the current monitoring signal and the ramp signal. An average current of the light source increases as the ramp signal increases until the average current reaches a predetermined level.09-02-2010
20110115391LED LAMP AND LED LAMP MODULE - A light emitting diode (LED) lamp. Brightness of the LED lamp is controlled by a dimmer and an external alternating current (AC) source is received via the dimmer. The LED lamp includes at least one LED, a rectifying-modulating-driving apparatus and a current holding compensator. The rectifying-modulating-driving apparatus is coupled between the LED and the dimmer for bridge-rectifying and modulating an AC source with a conducting angle from the dimmer to drive the LED. The current holding compensator is coupled to the rectifying-modulating-driving apparatus to provide a compensation current when the AC source with the conducting angle is lower than a voltage after being bridge-rectified.05-19-2011
20090256487Method for detection of non-zero-voltage switching operation of a ballast of fluorescent lamps, and ballast - A method detects a non-zero-voltage switching operation of a lamp ballast, the lamp ballast including a half-bridge circuit with a first and a second semiconductor switching element, a resonant circuit connected to the half-bridge circuit, and a snubber capacitance connected in parallel with one of the semiconductor switching elements. The method includes obtaining a voltage measurement signal representative of a voltage at an output of the half-bridge circuit. The method also includes providing a comparison signal representative of a comparison of the voltage measurement signal with a reference value. The method further includes evaluating the comparison signal in each case before the first semiconductor element is switched on and in each case before the second semiconductor element is switched on, and detecting one of a first and second non-zero-switching operations based on these evaluations.10-15-2009
20100253234POWER SUPPLY HAVING AN AUXILIARY POWER STAGE FOR SUSTAINING SUFFICIENT POST IGNITION CURRENT IN A DC LAMP - The current invention provides a power supply that includes an igniter that generates an ignition voltage for igniting a DC lamp; an auxiliary power stage that outputs an auxiliary voltage for sustaining sufficient current in the DC lamp after the DC lamp is ignited; a voltage conversion stage coupled to the auxiliary power stage and generating a voltage at a level that is higher than the auxiliary voltage; and a switch that couples the auxiliary voltage to the DC lamp and the voltage conversion stage for a predefined period of time.10-07-2010
20090322237APPARATUS AND METHOD ENABLING FULLY DIMMABLE OPERATION OF A COMPACT FLUORESCENT LAMP - An electronic ballast circuit and related method for enabling full range dimming of a gas discharge load such as a compact fluorescent lamp.12-31-2009
20090009099Lamp ballast circuit and driving method thereof - The present invention relates to a lamp ballast circuit and a driving method. The lamp ballast circuit includes a voltage detector for detecting the level of a first voltage corresponding to an input voltage, a controller including an oscillator for changing the oscillation frequency according to the level of the first voltage, and an output unit for changing the frequency of the output voltage in correspondence to the oscillation frequency. Therefore, a lamp ballast circuit having less power consumption and that is operable by a lesser input current with less THD and a driving method thereof are realized.01-08-2009
20100219763DEVICE AND METHOD FOR DIMMING LIGHT SOURCES - In various embodiments, a device for dimming a light source is provided. The device may include a two-wire power supply line having interposed therein a switch for controlling transfer of said power supply towards said light source; a capacitance located downstream of said switch being traversed by a charge current as said switch is switched on; and a pre-charge stage interposed between said switch and said capacitance; said pre-charge stage being configured to limit to a given value said charge current.09-02-2010
20100295461DRIVING CIRCUIT FOR AND SEMICONDUCTOR DEVICE FOR DRIVING LASER DIODE - A driving circuit supplies a suppression current (I11-25-2010
20100308741ELECTRONIC BALLAST FOR A DISCHARGE LAMP - An electronic ballast arrangement for a discharge lamp is provided. the electronic ballast arrangement may include an electronic ballast for a discharge lamp with a control application specific integrated circuit, the control application specific integrated circuit having a control input, which is characterized by the fact that the potential present across it sets the operating frequency of the control ASIC when driving the discharge lamp; and a switch; wherein the electronic ballast is connected to the switch, with different switching positions of the switch determining different potentials which are present at the control input, in order to thus set the operating frequency of the control application specific integrated circuit via the switch.12-09-2010
20130134893Led Controller Comprising a Clocked Current Source - The invention relates to an LED driver circuit comprising: a circuit block for providing an adjustable DC voltage and a clocked constant current source, e.g. a DC/DC converter that is supplied with the DC voltage, comprising a switch that is clocked by a control circuit in such a way that a reduction of the activation period ton of the switch leads to a reduction in the provision of power. One or more LEDs can be supplied from the constant current source and in addition to reducing the activation period t0N, the control unit is designed to change at least one other control variable of the constant current source or the circuit block in order to provide the direct current.05-30-2013
20130134895LED DRIVE CIRCUIT AND LED ILLUMINATION UNIT - There is provided an LED drive circuit that can be connected to an alternating-current power supply through a phase control dimmer and that drives an LED load, the LED drive circuit including: an LED current control circuit; a capacitance component and a resistance component that are connected in series between an input of the LED current control circuit and a reference potential; a switch element that is connected to both ends of the resistance component; and a switch control portion that turns off the switch element for a given period of time after a timing when the phase control dimmer is turned on and that turns on the switch element after the given period of time elapses.05-30-2013
20090167200SWITCHING POWER CONVERTER WITH CONTROLLED STARTUP MECHANISM - A switching power converter with a controlled startup mechanism includes a switching stage which provides a voltage V07-02-2009
20110018453HID LAMP BALLAST WITH MULTI-PHASE OPERATION BASED ON A DETECTED LAMP ILLUMINATION STATE - An electronic ballast is provided for improved startup and powering of a high pressure discharge lamp. The ballast includes an inverter, a starting circuit for generating a high voltage to ignite the lamp, a controller for controlling an operating frequency of the inverter from startup to steady-state lamp operation, and a lamp output detection circuit. The controller controls the inverter in association with one or more of a first phase in which the starting circuit generates the high voltage and causes dielectric breakdown between the lamp electrodes, a second phase in which an electrode heating operation is performed after dielectric breakdown and a third phase in which steady-state operation of the lamp is performed. A lamp output determination is performed at a predetermined time before shifting to the third phase, and upon determining that the lamp is ignited the second phase is inserted.01-27-2011
20110018454IMPROVEMENTS IN AND RELATING TO LOW POWER LIGHTING - Circuitry for driving an LED light source (01-27-2011
20120176059STROBE DEVICE AND MOBILE DEVICE - A strobe device of the present invention includes a flash discharge tube; a plurality of external triggering electrodes formed on an outer surface of the flash discharge tube; a trigger circuit that outputs a trigger signal to the external triggering electrodes causing the flash discharge tube to emit light at predetermined timing; and a control unit that controls and directs the trigger circuit to switch between a first mode in which a voltage is applied to any of the plurality of external triggering electrodes having a predetermined attachment area to the flash discharge tube, and a second mode in which a voltage is applied to another of the external triggering electrodes having an area larger than the predetermined area.07-12-2012
20110043120LAMP ASSEMBLY - A lamp assembly including one or more light emitting diode (LED) arrays and a controller circuit to output a current to the one or more LED arrays. Each LED array includes at least one LED and defines a spatial radiation pattern having a first central axis. The lamp assembly also includes a lens array to redirect light received from the one or more LED arrays, a base and a light-transmissive cover. For each one of the one or more LED arrays, the lens array includes a total internal reflection (TIR) lens defining a second central axis aligned with the first central axis of the corresponding LED array. The TIR lens is configured to distribute light received from the LED array from an output face of the TIR lens such that the distributed light defines optical paths that are convergent, divergent or collimated with respect to the second central axis. The base includes a first surface to receive the one or more LED arrays, the controller circuit and the lens array. The base also includes a second surface structured to be removably received by a lamp holder. The light-transmissive cover is attached to the base and disposed over the first surface thereof such that the one or more LED arrays, the controller circuit and the lens array are contained between the cover and the base.02-24-2011
20110043121LIGHTING CIRCUIT AND ILLUMINATION DEVICE - A lighting circuit according to embodiments includes: a self-hold element connected in series to an AC power source that generates power for lighting an illumination load, together with the illumination load, the self-hold element being configured to control supply of the power provided by the AC power source to the illumination load by the self-hold element being turned on/off; a noise prevention circuit connected in parallel to the self-hold element; and a damping circuit configured to connect a damping resistance to the noise prevention circuit parallely only for a predetermined period from turning-on of the self-hold element, thereby preventing the self-hold element from being repeatedly turned on/off during a period in which the self-hold element is on under normal conditions, due to a transient during power supply.02-24-2011
20100171434CIRCUIT ARRANGEMENT FOR OPERATING DISCHARGE LAMPS AND METHOD FOR OPERATING DISCHARGE LAMPS - A circuit arrangement for operating a discharge lamp is provided. The circuit arrangement may include a commutating device, which is configured to exhibit an input which is coupled to a direct-current source and has an output which can be coupled to a discharge lamp; the commutating device being configured in such a manner that it couples the direct-current source to the output and the polarity with which the direct-current source is coupled to the output can be commutated by a control device; the control device including a measurement input which is coupled to a measuring device which is configured to deliver a measurement value which is a measure of the magnitude of a lamp voltage; wherein the control device is configured to control the commutating device in such a manner that the polarity at which a higher lamp voltage prevails is coupled longer to the output.07-08-2010
20090033237FLUORESCENT TUBE POWER SUPPLY AND BACKLIGHT - A fluorescent tube power supply including a rectification circuit, a smoothing circuit, an inverter, and a control circuit for controlling the inverter, further includes a current detecting unit for detecting an input current of the inverter. The control circuit is stopped based on an output signal of the current detecting unit when the input current increases.02-05-2009
20100148683CIRCUIT FOR OPERATING LIGHT EMITTING DIODES (LEDS) - The present invention relates to a circuit arrangement for supplying power to, and for controlling, light-emitting diodes for illuminating, and to a method therefor. The invention provides a driver circuit for providing an operating current for operating at least one light-emitting diode, wherein the operating current has different positive intensities.06-17-2010
20110121743LIGHT EMITTING DIODE DRIVING CIRCUIT - A LED driving circuit includes a bridge rectifier, a high-bias-voltage diode, a balancing capacitor, a driving chip, and a switch. The bridge rectifier receives external AC power and outputs a full-wave or half-wave AC power. One terminal of the high-bias-voltage diode and one terminal of the balancing capacitor are electrically coupled to a balancing node. The other terminals of the high-bias-voltage diode and the balancing capacitor are electrically coupled to the bridge rectifier and grounded respectively. The driving chip receives operating power from the balancing node, and outputs driving signals to operate the switch, so as to drive an LED. Through the arrangement of the forward bias voltage direction of the high-bias-voltage diode, the balancing capacitor is only discharged to the driving chip. Therefore, the capacitance value and the volume of the balancing capacitor, the space occupied by the driving circuit, and the cost of the driving circuit are reduced.05-26-2011
20090315471METHOD AND DEVICE FOR DRIVING A CIRCUIT ELEMENT - Light emitting diodes (LEDs) are commonly used to backlight liquid crystal display screens for mobile telephones and other display devices. It may be desirable for the LEDs to be gradually dimmed and this can result in noise being emitted by the components of the driving circuit, along with other undesirable effects. A device for driving a circuit element is provided, comprising a voltage source (12-24-2009
20100253233DISCHARGE LAMP LIGHTING DEVICE AND LIGHT FIXTURE - In order to suppress cost of an initial investment by a user and running cost to the user to a low extent while substantially constantly maintaining an apparent illuminance, and further, to realize resource saving, in a case of using a fluorescent lamp FHF 10-07-2010
20100052556Digital Control Circuit of an Operating Device for Lamps - The invention relates to an integrated digital control circuit for an operating device for lamps, comprising: an output for the pulsing of switches of a half-bridge circuit having an adjustable frequency, wherein a load circuit comprising the lighting devices may be connected to the half-bridge circuit, an input, to which a signal may be selectively supplied, said signal reflecting the current through the half-bridge or the current through the lamp. The input is internally branched into two analysis branches, the outputs of which are combined using a logic member, the output of which is connected in turn to a controller for adjusting the frequency of the half-bridge actuating signal.03-04-2010
20100072907Power Line Preconditioner for Improved LED Intensity Control - A switched preconditioner circuit is provided at the power input end of a light source to effectively drop the voltage of the light source to zero volts whenever the light source is required to be in an OFF state thereby eliminating the problem of unwanted current through the light source. The preconditioner circuit may include a terminal connected to a first power potential, a terminal connected to a power node at the power input end of the light source, and an input to receive a preconditioner control signal to place the preconditioner circuit in one of an ON state and an OFF state. The preconditioner circuit supplies the voltage to the power node in its ON state and effectively eliminates the voltage to the power node in its OFF state. The preconditioner circuit also may include a bleed path connected between the power node and a second or ground potential to shunt all power supplied to the power node when the preconditioner circuit input receives a signal to place the preconditioner circuit in the OFF state.03-25-2010
20110101878DRIVING CIRCUIT FOR DRIVING A LOAD - A driving circuit comprises a first and a second switching circuit coupled in parallel to a node which is adapted to be coupled to a load, a first and a second detecting circuit, and a synchronizing circuit having an input coupled to the first and second detecting circuits and having an output coupled to the first and second switching circuits. The first detecting circuit detects a current associated with the first switching circuit and the second detecting circuit detects a current associated with the second switching circuit. The synchronizing circuit operates the first and second switching circuits to switch synchronously to a conducting state, and operates the first and second switching circuits to switch synchronously to a non-conducting state in the event that one of the first and second detecting circuits detects a current equal to or higher than a threshold value.05-05-2011
20100244716HIGH PRESSURE DISCHARGE LAMP BALLAST WITH ADAPTIVE FILAMENT HEATING CONTROL BASED ON LAMP AGE - A high pressure discharge lamp ballast is provided with adaptive power control during a filament heating period. A starting circuit is coupled along with a high pressure discharge lamp to output terminals of a DC-AC power converter and generates a high voltage for dielectric breakdown in the lamp. A control circuit controls output power from the power converter to the lamp during the filament heating period after dielectric breakdown of the lamp. The output power is controlled in accordance with a power output parameter which is further determined by the control circuit in accordance with one or more lamp parameters detected by a lamp status detection circuit. The lamp parameters may be cumulative lamp parameters or electrical characteristics associated with the lamp.09-30-2010
20100244715SELF-OSCILLATING TRANSFORMERLESS ELECTRONIC BALLAST - An electronic ballast includes a rectifier circuit having a first output terminal for coupling with a lamp; a first inductor coupled with a first node; a resonant network coupled with the first node; a first capacitor coupled with the first node; a first resistor coupled with a second node; a second resistor coupled with a second output terminal of the rectifier circuit; a power switch having an output end, a ground end and a control end, wherein the output end is coupled with the first node and the ground end is coupled with the second resistor; a voltage divider for driving the power switch; and a second inductor coupled between the second node and the control end of the power switch.09-30-2010
20100259181CONTROL CIRCUIT FOR LIGHT EMITTING DEVICE - A control circuit comprises a rectifier unit for performing full wave rectification on an AC power source, a switching element for switching a current flowing through a light emitting device which emits light in response to a voltage having been full wave rectified in the rectifier unit, a voltage dividing circuit for dividing the voltage having been full wave rectified in the rectifier unit to obtain a reference voltage Vref, a comparator for comparing a comparison voltage Vcmp corresponding to the current flowing through the light emitting device with the reference voltage Vref, and a control unit for controlling switching of the switching element based on a comparison result obtained in the comparator.10-14-2010
20110254458OUTPUT CONTROLLABLE FREQUENCY MODULATION ELECTRONIC BALLAST - An output controllable frequency modulation electronic ballast includes a first stage for converting AC current into DC current and boosting of voltage; a buck DC-DC converter; a transistor of the buck DC-DC converter having an input end which is selected from a gate for MOSFET and a base for a bipolar transistor; and a PWM controller connected between the input end of the buck DC-DC converter and an output end of the lamp body; a frequency controllable oscillator being connected to the PWM controller for providing variable frequency to the PWM controller as a base band signals of the PWM controller; and an oscillation controlling processor being connected to the frequency controller oscillator for generating instructions to change the oscillation frequency of the frequency controller oscillator and thus to adjust the modulation frequency of the output of the PWM controller.10-20-2011
20080284345Circuit Arrangement and Method for the Operation of High-Pressure Gas Discharge Lamps - Disclosed is a circuit arrangement for supplying a lamp wattage to a high-pressure discharge lamp (Lp) in the form of an alternating current having an operating frequency. The alternating current is generated by a full bridge that is composed of two half-bridge branches. The lamp wattage can be adjusted via the phase which the two half-bridge branches have relative to each other. The lamp wattage is modulated by means of the transmission function of an interface if the operating frequency is frequency-modulated. Said modulation of the lamp wattage can be compensated by adequately correcting the phase.11-20-2008
20080252227Method and Circuit for Driving Gas Discharge Lamps Using a Single Inverter - For driving one or more gas discharge lamps (10-16-2008
20080203935Limited current circuit for electro-luminescent lamp inverter - A current limiting device includes a constant current source circuit constructed and arranged to be connected to a direct current input voltage source and to regulate electrical current and a resonance source circuit receiving current from the constant current source circuit. The resonance source circuit is constructed and arranged to be electrically connected with an electro-luminescent (EL) lamp so that the EL lamp receives alternating current. The constant current source circuit and the resonance source circuit are constructed and arranged such that when current flows from the constant current source circuit to the resonance source circuit and to the EL lamp, a maximum peak current received by a user contacting an output of the device or contacting the EL lamp is less than about 0.7 mA.08-28-2008
20100320924DEVICE FOR CONTROLLING A DISCHARGE LAMP - An electro magnetic ballast (12-23-2010
20110133662CIRCUITS AND METHODS FOR DRIVING LIGHT SOURCES - A driving circuit includes a first inductor coupled in series with a light source for providing power to the light source. A controller coupled to the first inductor can control a switch coupled to the first inductor, thereby controlling a current flowing through the first inductor. A current sensor coupled to the first inductor can provide a first signal indicative of the current flowing through the first inductor, regardless of whether the switch is on or off. The switch is controlled according to the first signal. A second inductor magnetically coupled to the first inductor is also electrically coupled to the first inductor via a common node between the switch and the first inductor for providing a reference ground for the controller. The reference ground is different from the ground of the driving circuit.06-09-2011
20100188007SUPPLYING A SIGNAL TO A LIGHT SOURCE - Supply circuits for supplying voltage and current signals to light sources (07-29-2010
20100117548CIRCUIT ARRANGEMENT FOR IGNITING AND OPERATING A DISCHARGE LAMP - A circuit arrangement for starting and for operating a gas discharge lamp with an AC step-down converter or a half-bridge arrangement, which functions as a step-down inverter during quasi-resonant operation, a lamp inductor and a resonant capacitor, which form a resonant circuit, and a smoothing inductor, wherein the resonant capacitor is dimensioned in terms of its value such that, during normal operation of the lamp, a voltage ripple of over 100 V from maximum to maximum is present across said resonant capacitor, the smoothing inductor being dimensioned in such a way that it can filter the majority of the voltage ripple, and the switching frequency at the same time being between 200 kHz and 500 kHz.05-13-2010
20120146534DC/AC Inverter - A fluorescent lamp device includes a frequency generator for generating a pulse signal, a driver circuit coupled to said frequency generator for generating at least one driving signal according to said pulse signal, a half bridge power switch unit coupled to the driver circuit, a resonant tank coupled to the half bridge power switch unit, and a fluorescent lamp coupled to the resonant tank.06-14-2012
20120146533LIGHT-EMITTING DIODE DRIVING CIRCUIT CAPABLE OF CONTROLLING THE CURRENT OF A CONSTANT LIGHT-EMITTING DIODE - Disclosed is a light-emitting diode (LED) driving circuit. The LED driving circuit includes a switching element configured to provide or interrupt input power to an LED, a first sensing element connected to the LED and configured to generate a feedback voltage corresponding to a current flowing through the LED, a controller having the same reference voltage as the first sensing element and configured to control an on/off operation of the switching element on the basis of the feedback voltage, and a first inductor and a diode connected to the LED and configured to provide the LED with a current induced during the on operation if the switching element is turned off.06-14-2012
20120146531DRIVING CIRCUIT OF LIGHT EMITTING ELEMENT, LIGHT EMITTING DEVICE USING THE SAME, AND ELECTRONIC DEVICE - The present disclosure provides a driving circuit of a light emitting element including a switching power source for supplying a driving voltage to a first terminal of the light emitting element to be driven and a current driver connected to a second terminal of the light emitting element for supplying a driving current to the light emitting element while a burst dimming pulse is being asserted.06-14-2012
20110074302Phase Control Dimming Compatible Lighting Systems - A power control/lighting system includes a controller to provide compatibility between a lamp ballast configured to receive a dedicated dimmer signal and a phase control dimmer. In at least one embodiment, the controller converts a phase control dimming signal into dimming information useable by a lamp ballast of a gas discharge lamp based lighting system. Additionally, in at least one embodiment, the controller also controls power factor correction of the power control/lighting system. In at least one embodiment, the controller provides dimming information based on the phase control dimming signal that allows the lamp ballast to be used in conjunction with a phase control dimmer.03-31-2011
20100237793ELECTRONIC BALLAST WITH FEEDBACK CURRENT CONTROL FOR PREHEATING OF LAMP FILAMENTS - A discharge lamp ballast is provided for powering a discharge lamp with feedback filament heating control. A startup circuit is coupled between output terminals of a DC-AC power converter together with a discharge lamp. A lamp current detection circuit and a lamp voltage detection circuit detect output signals to the lamp. A control circuit controls the switching elements and generates an operating frequency in accordance with a startup operation to generate a high voltage output from the startup circuit and ignite the discharge lamp, a filament heating operation wherein the operating frequency is controlled so as to set the amplitude of the output current detected by the lamp current detection circuit to a target current amplitude based on the amplitude of the output voltage detected by the lamp voltage detection circuit, and a steady-state operation wherein the operating frequency is decreased to maintain a stable light output from the discharge lamp.09-23-2010
20100219764LED DIMMING APPARATUS - An LED dimming includes: current adjusting means (constant current circuit) for variably controlling a magnitude of a current flowing through an LED load; switching means (transistor) for intermittently controlling the current flowing through the LED load; and dimming controlling means (microcomputer) for controlling the current adjusting means and the switching means upon receiving a dimming signal outputted from a dimmer. In a case where the dimming signal outputted from the dimmer is on a higher brightness side than a predetermined level, the dimming controlling means flows a continuous current though the LED load, and dims the LED load based on a magnitude of the flowing current, and in a case where the dimming signal outputted from the dimmer is on a lower brightness side than the predetermined level, the dimming controlling means flows a pulse current through the LED load, and changes a mean value of waveforms of the pulse current, thereby dims the LED load. In this LED dimming apparatus, noise is less likely to occur even in a case where such an LED current is large, and brightness is less likely to vary even in a case where a dimming degree is increased.09-02-2010
20080218094Discharge Lamp Ballast, Lighting System and Projector - A discharge lamp ballast. Its starting means comprises a second inductor connected between a first end of a discharge lamp and the positive voltage side of a first capacitor; a second capacitor forming a resonance circuit together with the second inductor; a second switching element connected between the positive terminal of a DC power source and the second end of the lamp; a third switching element connected between the second end of the lamp and the negative voltage side of the first capacitor; and a starting control means that controls both switching elements. The starting control means alternately turns both switching elements on and off so as to contribute resonance voltage of the resonance circuit for starting of the lamp in case of the starting mode. According to the invention, noise from the starting means can be reduced.09-11-2008
20100194302STARTUP CONTROL FOR A HIGH PRESSURE DISCHARGE LAMP BALLAST - A high pressure discharge lamp ballast is provided with a control operation for stable transition from a lamp ignition mode into a preheating mode. An inverter is coupled across a DC source and has a plurality of switching elements coupled to the high pressure discharge lamp. A series resonant LC circuit is coupled to the inverter outputs and to the high pressure discharge lamp. A control circuit is coupled to the switching elements and configured to control switching operation. An ignition mode has one or more time periods during each of which a driving frequency of the switching elements is swept through a predetermined range of frequencies and then controlled at a first driving frequency less than the predetermined range of frequencies. A preheating mode follows wherein the switching elements are controlled at a second driving frequency less than the predetermined range of frequencies.08-05-2010
20100019684CURRENT REGULATOR APPARATUS AND METHODS - An apparatus according to the present invention provides regulated pulsed current to an LED from a voltage source such as a rectified AC voltage. The present inventions provide methods for delivering regulated pulsed current to an LED from the voltage source.01-28-2010
20100019683METHOD AND DEVICE FOR DRIVING A GAS DISCHARGE LAMP - A method is described for driving a gas discharge lamp (01-28-2010
20120146532CURRENT REGULATOR CIRCUIT FOR LED LIGHT - A regulator scheme for an LED light wherein the peak input current to the regulator and the regulator duty cycle produce a feedback signal which infers the average regulator output current. Both buck-boost and flyback type output circuits are disclosed.06-14-2012
20080218096Parasitic Capacitance Compensation System and Method - A parasitic capacitance compensation system and method, with a parasitic capacitance compensation circuit for an electronic ballast including a phase detector 09-11-2008
20100141164IGNITER CIRCUIT FOR AN HID LAMP - An igniter circuit (06-10-2010
20100259179HIGH RESOLUTION PULSE WIDTH MODULATION (PWM) FREQUENCY CONTROL USING A TUNABLE OSCILLATOR - A fluorescent lamp light intensity dimming control generates a pulse width modulation (PWM) signal at about a fifty percent duty cycle and has very fine frequency change granularity to allow precise and smooth light dimming capabilities. Intermediate PWM signal frequencies between the frequencies that are normally generated from values in a period register of the PWM generator are provided with a variable frequency clock source to the PWM generator. Selection of each frequency from the plurality of frequencies available from the variable frequency clock source may be determined from a value stored in a variable frequency clock register. A microcontroller may be used to select appropriate frequencies for dimming control of the fluorescent lamp from the variable frequency clock source, and the period and duty cycle values used in generating the PWM signal at about a fifty percent duty cycle.10-14-2010
20080203934Method and Circuit for Enabling Dimming Using Triac Dimmer - To enable dimming of an energy-saving lamp, in particular a gas discharge lamp, using a standard TRIAC dimmer circuit, a large additional current is drawn when the TRIAC is in a non-conductive state, and a small additional current is drawn when the TRIAC is in a conductive state. A current control circuit may be connected between the supply voltage and the ballast circuit of the lamp for drawing said additional currents. The current control circuit comprises two switches and a number of resistors for providing a large or a small resistance. In an embodiment, the amount of current drawn is controlled instead of the resistance using additional circuitry in the current control circuit.08-28-2008
20100320923DISCHARGE LAMP LIGHTING APPARATUS - In a discharge-lamp lighting apparatus, a switching frequency of an AC voltage applied to an LC series circuit including an inductor and a capacitor is swept near a frequency having a value provided by dividing the resonant frequency of the LC series circuit by an odd number at startup of a discharge lamp and is set to a frequency near or greater than the frequency after the sweeping after the switching frequency is swept to control the on-off duty ratio of switching elements in a DC-AC inverter circuit and, after the operation at startup of the discharge lamp is repeated once or more times, the switching frequency is set to less than the frequency after the sweeping to light the discharge lamp.12-23-2010
20110304275DISCHARGE LAMP LIGHTING DEVICE - A discharge lamp lighting device capable of simply and inexpensively suppressing generation of unpleasant sounds from an inductive element is provided without increasing size. A discharge lamp lighting device includes a commutator 12-15-2011
20120306400Digital Controller for an Electronic Ballast - Provided are circuits and methods for a digital controller for an electronic ballast for a fluorescent lamp, comprising a feed-forward loop that provides information about a voltage firing angle, and a pulse width modulator that controls a duty ratio of at least one power switch of the electronic ballast according to the information. The digital controller may include a duty ratio controller implemented in the pulse width modulator. The digital controller may include one or more functions such as dimming, maintaining high power factor throughout the dimming range, low lamp power detection, lamp soft-start, and DC-link capacitor over-voltage detection for end of life protection or lamp failure protection. In one embodiment the ballast is a single stage, single switch ballast.12-06-2012
20120306401LED dimming control scheme - In order to keep the advantage of PWM dimming control scheme and make the LED driver high reliability and the LED lamp long lifetime, it is required that the frequency of PWM dimming control scheme is related with or the same as the output frequency of existed dimmers; and the output PWM dimming pulse is covered by the output pulse from dimmers further. The present invention discloses a novel “LED dimming control” scheme to make that the frequency of PWM dimming control scheme is related with or the same as the output frequency of dimmers; and the output PWM dimming pulse is covered by the output pulse from the dimmers further. In this way, it can guarantee that as PWM dimming pulse comes, the output from the dimmer can offer enough power to the LED driver and the LED driver can output the required LED driving current without flicker.12-06-2012
20100134028LIGHT SOURCE - A light source comprises a discharge lamp (LA), a bridge circuit for driving the discharge lamp and a reflector (RE). The bridge circuit comprises a capacitor (C06-03-2010
20120043903Method of Measuring a Resonant Frequency in an Electronic Dimming Ballast - An electronic ballast for driving a gas discharge lamp comprises an inverter circuit, a resonant tank circuit, and a control circuit operable to determine an approximation of a resonant frequency of the resonant tank circuit and to control the inverter circuit in response to the approximation of the resonant frequency. The control circuit determines the approximation of the resonant frequency by adjusting an operating frequency of a high-frequency inverter output voltage provided to the resonant tank circuit from a frequency above the resonant frequency down towards the resonant frequency, measuring the magnitude of a lamp voltage across the lamp, and storing the present value of the operating frequency as the resonant frequency when the magnitude of the lamp voltage reaches a maximum value. The control circuit may control the operating frequency of the inverter output voltage in response to the approximation of the resonant frequency and a target intensity of the lamp.02-23-2012
20110316436DISCHARGE LAMP IGNITION APPARATUS AND DISCHARGE LAMP IGNITION METHOD - In a discharge lamp ignition apparatus, a control circuit unit: lowers a drive frequency from a predetermined initial frequency; establishing, if a resonant voltage reaches an ignition voltage for igniting a discharge lamp, a drive frequency at the ignition voltage as a discharge-lamp-ignition drive frequency which is a frequency for igniting the discharge lamp; and sets, if the resonant voltage does not reach the ignition voltage even though the drive frequency is lowered from the predetermined initial frequency to a resonant frequency, a frequency which is a predetermined value higher than the drive frequency at a resonant voltage peak voltage as the discharge-lamp-ignition drive frequency, and an inverter circuit unit alternating-current drives the resonant circuit unit at the discharge-lamp-ignition drive frequency established by the control circuit unit.12-29-2011
20110156607DC/AC Inverter - A direct current to alternating current (DC/AC) inverter is for driving a fluorescent lamp through quasi sine wave generation. The DC/AC inverter includes a frequency generator for generating a reference signal and a modulation signal, a pulse width modulator coupled to the frequency generator for providing a pulse width modulation signal according to said modulation signal, a driver circuit coupled to the pulse width modulator for generating at least one driving signal according to the pulse width modulation signal and the reference signal, a half bridge power switch unit coupled to the driver circuit, and a resonant tank coupled to the fluorescent lamp for outputting a quasi sine wave to drive the fluorescent lamp.06-30-2011
20120001562INDUCTIVELY COUPLED BALLAST CIRCUIT - A ballast circuit is disclosed for inductively providing power to a load. The ballast circuit includes an oscillator, a driver, a switching circuit, a resonant tank circuit and a current sensing circuit. The current sensing circuit provides a current feedback signal to the oscillator that is representative of the current in the resonant tank circuit. The current feedback signal drives the frequency of the ballast circuit causing the ballast circuit to seek resonance. The ballast circuit preferably includes a current limit circuit that is inductively coupled to the resonant tank circuit. The current limit circuit disables the ballast circuit when the current in the ballast circuit exceeds a predetermined threshold or falls outside a predetermined range.01-05-2012
20100117547LAMP BALLAST AND AN ILLUMINATION APPARATUS - A lamp ballast capable of lighting a discharge lamp and an incandescent lamp each at an optimum condition. The lamp ballast has a DC-DC converter, an inverter that converts an output of DC-DC converter into an AC power for applying the same to a lamp load, a starting circuit generating a high voltage pulse from the AC power to provide the same to the lamp load, and a controller that controls the DC-DC converter and the inverter to provide a variable DC voltage and the AC power of variable frequency. The controller has a starting mode of operating the inverter at a starting frequency to generate the high voltage, and a lighting mode of operating the inverter at a lighting frequency lower than the starting frequency. The controller has a detection mode of causing the DC-DC converter to output a detection voltage of a predetermined level prior to the starting mode, a discharge lamp lighting program of operating, after the detection mode, the inverter in the starting mode and subsequently in the lighting mode, and an incandescent lamp lighting program of operating, after the detection mode, the inverter in the lighting mode without through the starting mode. When the detection voltage exceeds a predetermined threshold, the controller selects the discharge lamp lighting program, and otherwise selects the incandescent lamp lighting program. When the incandescent lamp is connected, the ballast turns on the incandescent lamp without applying a high voltage pulse so as to avoid lowering of the lamp life.05-13-2010
20120007517LIGHT EMITTING MODULE AND ILLUMINATING DEVICE - To a constant-current power supply whose output current can be variably set, light emitting modules can be connected in parallel. A control unit recognizes connection information outputted from an information output unit provided in each of the light emitting modules and varies the output current of the constant-current power supply. Drive can be controlled in response to a state of the connected light emitting modules such as the connecting number of light emitting modules.01-12-2012
20120013264POWER SUPPLY APPARATUS FOR LIGHT EMITTING DIODE - A power supply apparatus for LED is provided. The power supply apparatus for LED includes a detector, a voltage dropper, and a control switch. The detector detects whether an LED is connected to the power supply apparatus. The voltage dropper drops a voltage applied to the LED. The control switch is connected to the voltage dropper in parallel, and changes a path of a power applied to the LED according to the detected result of the detector. Accordingly, the power supply apparatus for LED compensates for a low impedance of an LED to an impedance equal to or higher than a predetermined impedance at a time when connection of the LED is detected, thereby inhibiting an overcurrent from flowing in the LED.01-19-2012
20120112653Electronic ballast for operating at least one discharge lamp - An electronic ballast for operating at least one discharge lamp may include an input having a first and a second input connection for coupling to a DC supply voltage; a load circuit having an output; a constant-current transformer which includes a converter throttle, a converter diode and a converter switch, whereby the converter throttle is coupled serially between the first input connection and the load circuit; an activation circuit which is configured to activate the converter switch during operation with an HF signal; wherein at least one component across which a second voltage which is opposite in phase to the first voltage drops during operation is coupled between the internal and the external reference potential.05-10-2012
20120112652DRIVER CIRCUIT FOR LIGHT-EMITTING DEVICE - A driver circuit for a light-emitting device includes a light-emitting device, a data receiving unit, a storage unit, a driver unit and a voltage divider. The data receiving unit receives a data signal, the storage unit stores a capacitor voltage, and a positive correlation exists between the capacitor voltage and the data signal. The driver unit is coupled to the light-emitting device, and the driver unit is turned on to drive the light-emitting device according to the capacitor voltage and to generate a threshold voltage of the driver unit. The voltage divider is coupled between the data receiving circuit and the light-emitting device and turned on by the capacitor voltage to generate a divided voltage. The voltage divider detects a voltage variation in the threshold voltage and in a voltage across the light-emitting device and adjusts the divided voltage according to the voltage variation.05-10-2012
20120112651DUTY FACTOR PROBING OF A TRIAC-BASED DIMMER - A power supply circuit for operating high-efficiency lighting devices from a thyristor-controlled dimmer determines the dimming value, i.e., the dimmer duty factor by periodically probing the dimmer output. A minimum conductance is applied across the output of the dimmer during probing intervals that begin at the turn-on time of the dimmer and last until enough information has been gathered to correctly predict a next zero crossing of the AC line voltage that supplies the input of the dimmer. The dimming value is determined from the time interval between the predicted zero-crossing and a next turn-on time of the dimmer. The probing can be performed at intervals of an odd number of half-cycles of the AC line frequency so that a DC offset is not introduced within internal timing circuits of the dimmer. The AC line frequency can also be determined from a time interval between the predicted zero crossings.05-10-2012
20120025730Circuit Arrangement and Method for Operating a High-Pressure Discharge Lamp - A circuit arrangement for operating a high-pressure discharge lamp (02-02-2012
20120025729POWERING HIGH-EFFICIENCY LIGHTING DEVICES FROM A TRIAC-BASED DIMMER - A circuit for powering high-efficiency lighting devices from a thyristor-controlled dimmer predicts a zero-crossing time of the AC power line supplying the dimmer and causes a glue impedance to be imposed at the output of the dimmer starting at the time of the zero-crossing, so that the timer in the dimmer will operate properly to generate the turn-on event at the correct time. At turn-on, a lower level of impedance is presented to absorb the energy associated with the turn-on event. A higher level of impedance may be presented after the energy is absorbed until all of the energy needed for the cycle is transferred. Then, a high impedance state is maintained until the next zero-crossing time. The impedance control may be provided by non-uniform operation of a power converter that supplies the lighting devices, or by a combination of non-uniform power converter operation and dissipative loading.02-02-2012
20120062136Direct current light emitting device control circuit with dimming function and method thereof - The present invention discloses a direct current (DC) light emitting device control circuit with dimming function, and a method thereof, wherein the dimming function is provided in a feedback loop for feeding back a feedback signal from an output terminal to a power switch control circuit; the feedback signal relates to an output current supplied to the DC light emitting device. The present invention adjusts the feedback signal according to the desired brightness of the DC light emitting device. The present invention controls a power switch according to the adjusted feedback signal, such that the output current supplied to the DC light emitting device is adjusted, and accordingly the brightness of the DC light emitting device is adjusted below the full brightness.03-15-2012
20110068705DRIVER SYSTEM AND METHOD WITH MULTI-FUNCTION PROTECTION FOR COLD-CATHODE FLUORESCENT LAMP AND EXTERNAL-ELECTRODE FLUORESCENT LAMP - System and method for driving a cold-cathode fluorescent lamp. The system includes a control subsystem configured to generate one or more control signals, and a power supply subsystem configured to receive the one or more control signals and a DC input voltage, convert the DC input voltage to an AC output voltage, and send the AC output voltage to a cold-cathode fluorescent lamp. If the DC input voltage is lower than a predetermined threshold, the system for driving the cold-cathode fluorescent lamp is turned off in response to the one or more control signals.03-24-2011
20120153857POWER SUPPLY AND DISPLAY DEVICE INCLUDING THE SAME - The power supply includes: an electromagnetic interference filter including a first filter which has a pair of electromagnetically coupled cores having at least two leg parts, first and second bobbins each having a tube-shaped body part having a penetration hole into which each of the leg parts is inserted and having a winding region defined as the circumference of the outer peripheral surface of the body part, and first and second coils respectively wound around the first and second bobbins to remove common mode electromagnetic interference included in power transmitted from a power line, the electromagnetic interference filter removing differential mode electromagnetic interference due to leakage inductance formed due to the leakage of magnetic flux flowing through the cores; a power factor corrector correcting a power factor of the power where the electromagnetic interference is removed; and a power converter switching the power-factor-corrected power into a driving power having a predetermined voltage level.06-21-2012
20130181631DRIVE UNIT, SMOOTHING CIRCUIT, DC/DC CONVERTER - A drive unit has a load driving portion driving a load by a PWM drive method; a soft-start function portion for achieving a soft-start function; and a soft-start disabling portion counting a time elapsed after a PWM signal is turned on at start-up of the unit, and disabling the soft-start function when a count value reaches a predetermined value.07-18-2013
20120119666METHOD FOR CONTROLLING HIGH INTENSITY DISCHARGE LAMP AND SUPPLY SYSTEM FOR HIGH INTENSITY DISCHARGE LAMP - Methods and apparatus for controlling a high intensity discharge lamp and a power supply system for the high intensity discharge lamp are disclosed. The system relates to a method for controlling high intensity discharge lamp comprising supplying a signal of variable frequency and constant filling factor from a switches cascade to a ballast circuit and the lamp, said ballast circuit having at least one condenser and at least one inductance. The method uses the signal of periodically fluctuating frequency and constant filling factor 50 to 50%, supplied from the electronic switches cascade of the half-bridge type, connected with the ballast circuit and the lamp, where the ballast circuit includes at least first condenser, the lamp and includes first inductance and second condenser forming a resonant circuit. A supply system for high intensity discharge lamp is also disclosed.05-17-2012
20120249007SWITCHING POWER SUPPLY DEVICE AND LIGHTING APPARATUS - According to one embodiment, a switching power supply device includes a direct-current power supply and a switching operation conversion circuit. The switching operation conversion circuit is connected to the direct-current power supply, and includes an inductor, a switching element, a diode, a gate drive circuit, an input end and an output end. The switching element allows an increasing current to flow to the inductor from the direct-current power supply at an on time of the switching element. The diode allows a decreasing current to flow to the inductor at an off time of the switching element. The gate drive circuit controls a gate voltage of the switching element to turns off the switching element when the increasing current reaches a saturated state relative to a source-drain voltage of the switching element. The input end is connected to the direct-current power supply. The output end is connected with a load.10-04-2012
20120126715DISCHARGE LAMP LIGHTING APPARATUS - A discharge lamp lighting apparatus has a configuration including a control unit which discriminates, for each polarity of an AC rectangular wave output, the output voltage detected with an output voltage detector for detecting the voltage applied to a discharge lamp, and carries out constant power control for each polarity separately. By thus detecting the output voltage for each polarity separately and by outputting a target current for each identical polarity, it can carry out constant power control positively even if the output voltage varies for each polarity, thereby being able to prevent current feedback to a different polarity, and to prevent power oscillation and partial reduction of electrodes due to an increase of the output voltage difference for each polarity.05-24-2012
20120212148LED LIGHTING DEVICE AND ILLUMINATION APPARATUS INCLUDING SAME - An LED lighting device includes two or more switching circuits connected between a power source and an LED (light emitting diode) unit, an inrush current limiting circuit which limits an inrush current flowing through the LED lighting device when power is turned on and a trigger circuit which generates a trigger signal of an operation/non-operation of the inrush current limiting circuit from the switching circuits. Further, the inrush current limiting circuit is set in a non-operation state when any one of the switching circuits is started first.08-23-2012
20120133296Circuitry for portable lighting devices and portable rechargeable electronic devices - A portable electronic device, such as a flashlight, with a circuit for reducing the initial surge of current that is sent through the lamp filament when a flashlight is turned on is provided. The circuit reduces the stresses placed on the lamp bulb when it is turned on, thereby extending the life expectancy of the lamp bulb. A flashlight with beacon mode that produces light according to a duty cycle of less than 11% is also disclosed.05-31-2012
20120313543TRANSFORMER AS WELL AS SWITCHING POWER SUPPLY AND LED FLUORESCENT LAMP APPLYING SAME - A transformer as well as a switching power supply and a LED fluorescent lamp applying the same. The transformer comprises: a framework (12-13-2012
20100194301Light emitting diode driving circuit - In a driving circuit for controlling a brightness of a light emitting diode based on a duty ratio of a pulse-width modulation signal, an integration circuit is disposed on a connecting line between a gate of a first transistor coupled with a constant current source and a gate of a second transistor coupled in series with a light emitting diode. The integration circuit smoothes a change in a gate voltage of the first transistor and transmit a smoothed change in the gate voltage to the gate of the second transistor. A third transistor is coupled between a ground and a portion of the connecting line located between the gate of the first transistor and the integration circuit. The third transistor is activated and deactivated based on the duty ratio, thereby changing the gate voltages of the first transistor and the second transistor.08-05-2010
20100176738DEVICE FOR DRIVING A GAS DISCHARGE LAMP07-15-2010
20120176058POWER SUPPLY DEVICE - An electrical supply device may include a transformer with a secondary winding to feed a current to a load; control circuitry for the device; an auxiliary supply source for said control circuitry. The auxiliary supply source may include an output capacitor across which a supply voltage is provided for said control circuitry; at least one charge accumulation capacitor to be traversed by the current fed to said load; a comparator sensitive to the voltage on said at least one charge accumulation capacitor; and a switch interposed between said at least one charge accumulation capacitor and said output capacitor, said switch coupled to said comparator, whereby when the voltage on said at least one charge accumulation capacitor reaches a reference level, said switch couples said at least one charge accumulation capacitor to said output capacitor by transferring onto said output capacitor the charge on said at least one charge accumulation capacitor.07-12-2012
20100270938ELECTRONIC BALLAST FOR HID LAMPS WITH ACTIVE LAMP POWER CONTROL - An electronic ballast includes a ballast control circuit controlling an inverter circuit to supply a rectangular wave AC power to a high-pressure discharge lamp. The ballast control circuit includes a load voltage detection circuit adapted to detect load voltages of both positive and negative polarities applied to the lamp, a comparison and selection circuit adapted to compare the detected load voltages of the positive and negative polarities and select one of the positive and negative polarities, and a switching control circuit adapted to use the load voltage of the polarity selected by the comparison and selection circuit for controlling load current in one cycle after a period of detecting the load voltages of both the positive and negative polarities.10-28-2010
20120256555DISCHARGE LAMP LIGHTING DEVICE, PROJECTOR, AND DISCHARGE LAMP LIGHTING METHOD - A discharge lamp lighting device includes a voltage pulse applying section adapted to apply a voltage pulse for causing dielectric breakdown between first and second electrodes of a discharge lamp, an alternating-current voltage applying section adapted to apply an alternating-current voltage to the discharge lamp, the alternating-current voltage including a first polarity period in which the first electrode acts as an anode and a second polarity period in which the second electrode acts as the anode, and a control section. The control section controls the voltage pulse applying section to cause the dielectric breakdown, and thereafter controls the alternating-current voltage applying section to apply the alternating-current voltage having the first polarity period longer than the second polarity period to the discharge lamp, and thereafter to apply the alternating-current voltage having the second polarity period longer than the first polarity period to the discharge lamp.10-11-2012
20120256554LIGHT SOURCE DRIVER - A light emitting diode (LED) driver is provided that includes a light emitting diode, a converter connected to the light emitting diode, wherein the converter receives an input voltage and converts the input voltage to a basic voltage for driving the light emitting diode, a current regulator connected to the light emitting diode, a first operational amplifier connected to the current regulator, an analog dimming voltage generating unit including a second operational amplifier, a first resistor, a second resistor, and a third resistor, wherein a first terminal of the first resistor, a first terminal of the second resistor, and a first terminal of the third resistor are connected to a non-inversion terminal of the second operational amplifier, and connected to the first operational amplifier, and a pulse-width-modulation dimming pulse generating unit connected to a second terminal of the third resistor.10-11-2012
20120262082SEMICONDUCTOR LIGHT-EMITING ELEMENT DRIVER CIRCUIT AND LIGHT FIXTURE USING THE SAME - A driver circuit for a semiconductor light-emitting element enables stable dimmed lighting from very low luminance output to rated luminance output by use of a switching power source operating in a discontinuous mode. The driver circuit includes a DC-DC converter, an output sensor, and a feedback controller. The DC-DC converter includes a burst dimming controller for intermittently stopping an ON/OFF operation of a power switch of the DC-DC converter, thereby reducing a current flowing to the semiconductor light-emitting element. The output sensor detects at least one of the current provided to the semiconductor light-emitting element or the voltage of the semiconductor light-emitting element. The feedback controller adjusts an ON time of the power switch during the ON/OFF operation such that a detected value of the output sensor approaches a target value. Near a dimming control lower limit, power is blocked from the feedback controller.10-18-2012
20120299503RESONANT FLY-BACK POWER CONVERTER AND LED LIGHTING UNIT POWERED THEREFROM - A method for controlling powering with a resonant fly-back power converter includes powering an output circuit including a load, with a inductor of a resonant fly-back power converter including a primary winding electrically connected to an input circuit of the fly-back converter and secondary winding electrically connected to the output circuit of the fly-back converter, operating the converter in a discontinuous conduction mode. Charging and discharging of the primary winding is controlled with a first and second switching element and a capacitor connected across the second switching element selected for resonating with the primary winding. Both first and second switching elements are operative to connect primary winding to an input voltage source over a defined on-time. The pulsing of the first and second switching elements is synchronized and the on-time of the second switching element is extended with respect to the on-time of the first switching element.11-29-2012
20120299502CIRCUITS AND METHODS FOR DRIVING LIGHT SOURCES - A controller for controlling power to a light source includes a first sensing pin, a second sensing pin, a third sensing pin, and a driving pin. The first sensing pin receives a first signal indicating an instant current flowing through an energy storage element. The second sensing pin receives a second signal indicating an average current flowing through the energy storage element. The third sensing pin receives a third signal indicating whether the instant current decreases to a predetermined current level. The driving pin provides a driving signal to a switch to control an average current flowing through the light source to a target current level. The driving signal is generated based on one or more signals selected from the first signal, the second signal and the third signal.11-29-2012
20120299501Switching Power Converter Control With Triac-Based Leading Edge Dimmer Compatibility - In at least one embodiment, a controller allows triac-based dimmer to properly function and dim a load whose voltage is regulated by a switching power converter. In at least one embodiment, the switching power converter includes a switch to control voltage conversion of an input voltage to the switching power converter, wherein phase delays are introduced in the input voltage by a triac-based dimmer during a dimming period. In at least one embodiment, the controller is configured to control the switch of the switching power converter to establish an input resistance of the switching power converter during a dimming portion of the input voltage, wherein the input resistance allows the triac-based dimmer to phase modulate a supply voltage to the dimmer so that an output voltage of the dimmer has a substantially uninterrupted phase delay during each half-cycle of the supply voltage during the dimming period.11-29-2012
20120299500Dimmable Timer-Based LED Power Supply - Various embodiments of a dimmable power supply are disclosed herein. For example, some embodiments provide a dimmable power supply including an input current path, a switch in the input current path, an energy storage device connected to the input current path, a load output connected to the energy storage device, and a timer-based variable pulse generator connected to a control input of the switch. The timer-based variable pulse generator is adapted to generate a stream of pulses having a variable on-time and off-time. The dimmable power supply is adapted to vary the on-time and off-time to control a current at the load output.11-29-2012
20080297062ILLUMINATING DEVICE - To a constant-current power supply whose output current can be variably set, light emitting modules can be connected in parallel. A control unit recognizes connection information outputted from an information output unit provided in each of the light emitting modules and varies the output current of the constant-current power supply. Drive can be controlled in response to a state of the connected light emitting modules such as the connecting number of light emitting modules.12-04-2008
20100060181AC LED DIMMER AND DIMMING METHOD THEREBY - The disclosure relates to an AC LED dimmer and dimming method thereof. The AC LED dimmer includes a rectifier receiving AC voltage from an AC voltage source and full-wave rectifying the AC voltage; a direct current (DC)/DC converter receiving the full-wave rectified voltage from the rectifier, generating a full-wave rectified stepped-up voltage, and generating a pulse enable signal; a pulse width modulation controller receiving the full-wave rectified stepped-up voltage and generating a pulse width modulation signal to dim an AC LED in response to the pulse enable signal; a switch driving the AC LED under control of the pulse width modulation signal, and an electromagnetic interference (EMI) filter to be connected between the AC voltage source and the switch to eliminate electromagnetic interference from the AC voltage source. Accordingly, the dimmer can perform an efficient and linear dimming function and suppress harmonics.03-11-2010
20120319611Boost Circuit for LED Backlight Driver Circuit - A boost circuit for an LED (Light Emitting Diode) backlight driver circuit is disclosed; said boost circuit includes a PWM (Pulse Width Modulation) chip, a second capacitor, and a signal processing circuit. A VCC pin of the PWM chip is coupled to the input node, and the PWM chip is utilized to generate a PWM signal. One end of the second capacitor is coupled to an output pin of the PWM chip, and the second capacitor is utilized to filter out a direct current component of the PWM signal. One terminal of the signal processing circuit is coupled to the second capacitor, and another terminal thereof is coupled to a gate of the switch. The signal processing circuit is used to adjust the filtered PWM signal for generating corresponding high levels and low levels. A regulator is omitted in the present invention, therefore reducing costs.12-20-2012
20120326618HARMONIC RIPPLE-CURRENT LIGHT EMITTING DIODE (LED) DRIVER CIRCUITRY AND METHOD - In accordance with the presently claimed invention, circuitry and a method are provided for using a voltage to drive a light emitting diode (LED) load including one or more LEDs. The incoming voltage is switched and inductively conditioned to drive the LED load in such a manner as to cause the LED load to appear as a substantially linear resistive load, thereby maximizing the power factor presented to an AC power grid serving as the source of the input voltage.12-27-2012
20120268027ENERGY SAVING LED HAVING DIMMING FUNCTION AND MOOD-LIGHTING CONTROL FUNCTION - An energy saving LED lamp is disclosed. The LED lamp can control dimming or mood-lighting operation through repeated on/off operations of a simple power switch currently installed in a building, thereby eliminating requirement for any additional labor to change the existing switch or device for obtaining a dimming function or mood-lighting control function.10-25-2012
20120081021DRIVING CIRCUIT FOR AND SEMICONDUCTOR DEVICE FOR DRIVING LASER DIODE - A driving circuit supplies a suppression current (I04-05-2012
20130020961AUTOMATIC LOAD DISCRIMINATION CIRCUIT FOR REMOTE CONTROL RECEIVING CONTROLLER OF LAMP - An automatic discrimination circuit of load for a remote control receiving controller of a lamp, including: a switch control circuit for controlling a lamp load to be ducted with a power supply; a load type sampling circuit for sampling voltage signals at two ends of the lamp load; a remote control receiving control chip of the lamp for inputting a PWM dimming signal sequence into the switch control circuit and then comparing the PWM dimming signal sequence with a voltage waveform sequence at two ends of the lamp load sampled by the load type sampling circuit for determining the type of the lamp load; a wireless receiving module connected with the remote control receiving control chip for receiving a remote control command of an external remote controller; and an external memory chip connected with the remote control receiving control chip for storing load control mode digital information.01-24-2013
20100231134ELECTRIC-DISCHARGE LAMP LIGHTING DEVICE AND LIGHTING FIXTURE - An electric-discharge lamp lightning device includes a first frequency controller for sweeping a switching frequency so that the output of an inverter is gradually increased in order to allow an electric-discharge lamp to be started and lighted, and a second frequency controller for detecting the output power of the inverter by a current flowing in a resonant circuit and controlling the switching frequency so that the output power is set to be a target value after the discharge lamp is started and lighted. The first frequency controller includes a holding means for holding the switching frequency just after the lighting detection when the output power is smaller than the target value at the lighting detection of the electric-discharge lamp by a lighting detection circuit.09-16-2010
20120286686LIGHTING DEVICE FOR SOLID-STATE LIGHT SOURCE AND ILLUMINATION APPARATUS USING SAME - A lighting device for lighting a solid-state light source includes: a DC power circuit unit for converting a power of an input DC power source using a switching element and flowing a current through a solid-state light source; and a control unit for performing a first switching control in which the switching element is turned on/off at a first high frequency and a second switching control in which an ON/OFF operation of the switching element is intermittently stopped at a second frequency lower than the first frequency of the first switching control. When the current flowing through the solid-state light source is changed, the second frequency is varied.11-15-2012
20120286687SEMICONDUCTOR LIGHT SOURCE LIGHTING CIRCUIT - A semiconductor light source lighting circuit includes a switching regulator that produces a drive current I11-15-2012
20120286685LED CURRENT SOURCE DIGITAL TO ANALOG CONVERTOR - Various embodiments relate to a method of producing a high precision current using N current mirrors, a feedback control amplifier, and a reference current regulator to drive a light emitting diode, including: selecting one of the N current mirrors as a first current mirror; driving the first current mirror using a reference current produced by the reference current regulator; measuring a first sense voltage at the first current mirror; measuring a second sense voltage at a second current mirror that is one of the remaining N−1 current mirrors; integrating a difference of the first sense voltage and the second sense voltage to produce a feedback signal; and driving the remaining N−1 current mirrors using the feedback signal.11-15-2012
20120286684Controlled Power Dissipation In A Switch Path In A Lighting System - A lighting system includes one or more methods and systems to control dissipation of excess power in the lighting system when the power into a switching power converter from a leading edge, phase-cut dimmer is greater than the power out of the switching power converter. In at least one embodiment, the lighting system includes a controller that controls dissipation of excess energy in the lighting system to prevent a premature disconnection of the phase-cut dimmer. In at least one embodiment, the controller actively controls power dissipation by generating one or more signals to actively and selectively control power dissipation in the lighting system. By actively and selectively controlling power dissipation in the lighting system, the controller intentionally dissipates power when the power into the lighting system should be greater than the power out to a lamp of the lighting system. In at least one embodiment, the controller creates one or more intermixed and/or interspersed power dissipation phases with one or more switching power converter charging and/or flyback phases.11-15-2012
20120133297Method for Actuating a Discharge Lamp and Circuitry for Operating Such a Lamp - A method for actuating a discharge lamp (LP), wherein in order to ignite the lamp a resonant circuit (L, C05-31-2012
20100181925Ballast/Line Detection Circuit for Fluorescent Replacement Lamps - Disclosed herein is a replacement light for a fluorescent tube usable in a fluorescent fixture connected to a power source and containing at least one LED, the improvement including a detection circuit for connection to the power source, the detection circuit configured to identify the power source.07-22-2010
20130020960POWER SUPPLY WITH CHARGE PUMP AND CONTROL METHOD THEREOF - The present invention provides a power supply comprising a driver and a charge pump. The driver is configured to provide a driving signal to a load. The charge pump comprises a first capacitor coupled to the load in parallel, at least one flying capacitor, a second capacitor and a switch array comprising a plurality of switches. The switch array is coupled to the first capacitor, the second capacitor and the at least one flying capacitor. The switch array receives the voltage across the first capacitor and controls the charge and discharge of the at least one flying capacitor, so as to make the voltage across the second capacitor be larger than the voltage across the first capacitor.01-24-2013
20130020959HIGH INTENSITY DISCHARGE LAMP CONTROL CIRCUIT AND CONTROL METHOD - A high intensity discharge lamp (HID) control circuit and method are provided in the present invention. The circuit includes a first winding and a second winding, both of which are coupled with a series-connected inductor of an HID lamp circuit; a current zero point detector for detecting an inductor current zero crossing signal in the HID lamp circuit; an inductor current signal generator for generating an inductor current signal in the circuit to indicate a current value of the HID lamp; a modulator having input terminals connected to the current zero point detector and the inductor current signal generator, respectively, and an output terminal connected to a driving circuit for the HID lamp; and the driving circuit for driving switches in the HID lamp control circuit.01-24-2013
20080224627Regulated Charge Pump and Method Therefor - In one embodiment, a charge-pump controller is formed to control a value of current supplied to a load.09-18-2008
20130141003LIGHTING APPARATUS AND ILLUMINATING FIXTURE WITH THE SAME - The lighting apparatus in accordance with the present invention includes: a switching regulator including a switching element; and a control circuit configured to adjust a switching frequency and on-duration of the switching element in accordance with a dimming ratio. The control circuit is configured to, when the dimming ratio falls within a first dimming range, adjust the switching frequency to a frequency associated with the first dimming range and adjust the on-duration to duration corresponding to the dimming ratio. The control circuit is configured to, when the dimming ratio falls within a second dimming range, adjust the on-duration to duration associated with the second dimming range and adjust the switching frequency to a frequency corresponding to the dimming ratio.06-06-2013
20130175940SUPPLEMENTAL DIMMING CIRCUIT FOR ELECTRONIC LED DRIVER - A supplemental dimming circuit for an electronic led driver comprising a universal control section has a VCC3 startup and low conduction period circuit for providing a current during start-up and during low conduction periods; a CC hold current circuit for providing a hold current for the dimmer at low conduction periods; a latch circuit for providing a current draw latch on; and a PWM synchronized dimming circuit for providing a PWM signal dependent on the conduction period of the dimmer in real time. The supplemental dimming circuit also has a socket and a plug. The universal control section is on a daughter board that is pluggable to the socket. The VCC3 startup and low conduction period circuit creates a low AC voltage dummy load, which is a resistive load. The CC hold current circuit creates a low AC current dummy load that is a constant current load.07-11-2013
20130141002LIGHTING APPARATUS AND ILLUMINATING FIXTURE WITH THE SAME - In a first control mode, a control circuit turns a switching element on and off at a predetermined oscillating frequency and an On time so that a current flows through inductor in continuous mode without a sleep interval. In a second control mode, control circuit fixes oscillating frequency of switching element and changes On time of switching element. In a third control mode, control circuit fixes On time of switching element and changes oscillating frequency of switching element. Second control mode and third control mode are allocated for at least two intervals of intervals into which a dimming range is divided. Control circuit selects first control mode to fully light a light source load, and then, if a dimming ratio is designated, control circuit selects one of second and third control modes according to the interval, to which the dimming ratio corresponds, to dim light source load.06-06-2013
20130169183ILLUMINATION CONTROL CIRCUIT AND ILLUMINATION CONTROL METHOD - The invention discloses an illumination control circuit and an illumination control method. The illumination control method includes modulating an alternating current input signal and accordingly generating a dimming signal, which includes several waveform pulses each with an adjustable conduction angles; continuously sampling the waveform pulses of the dimming signal and forming an average waveform pulse from the sampled waveform pulses; extracting the average waveform pulse, which has an average conduction angle corresponding to the conduction angles of the waveform pulses; performing an integration on the sampled average waveform pulse and accordingly generating a current-controlling signal; and driving an illumination lamp according to the current-controlling signal.07-04-2013
20130169184LIGHT SOURCE CONTROL DEVICE AND LIGHT SOURCE CONTROL METHOD - A light source control device controlling a light source that emits light corresponding to supplied current and a color wheel having a plurality of color segments that converts the light emitted from the light source, the light source control device includes: a current generation circuit, which supplies current to the light source, based on a control signal for controlling an amount of the light of the light source; and a control circuit unit, which stores a plurality of modulation factors corresponding to the plurality of color segments and has a plurality of calculation units corresponding to the plurality of color segments, and which operates the calculation unit corresponding to the segment in synchronization with each segment to thus calculate control information of the control signal.07-04-2013
20080218095Led Assembly and Module - A light emitting diode (LED) assembly and module including a substrate (09-11-2008
20120249008DRIVING CIRCUIT FOR LCD BACKLIGHT SOURCE - A driving circuit for a LCD backlight source comprising a BOOST structure which comprises a capacitor C10-04-2012
20130134896LIGHT EMITTING DEVICE, METHOD OF DRIVING PIXEL CIRCUIT, AND DRIVING CIRCUIT - A method of driving a pixel circuit is provided. The pixel circuit includes a light emitting element that emits light by receiving a driving current, a driving transistor that generates the driving current, and a light-emission control transistor of the same conductivity type as that of the driving transistor, the light-emission control transistor being arranged on a path through which the driving current flows from the driving transistor to the light emitting element. The method includes setting the gate potential of the light-emission control transistor so that the light-emission control transistor is turned on in the saturation region for a light emitting period during which the light emitting element is allowed to emit light.05-30-2013
20130134894SWITCH-MODE POWER SUPPLY, CONTROL CIRCUIT AND ASSOCIATED DIMMING METHOD - A switch-mode power supply and associated control circuit for a light-emitting device are disclosed. The switch-mode power supply having a first switch which is turned ON or OFF by a control signal. The control circuit having an error amplifier, a minimum-off time control circuit and a logic circuit, wherein the error amplifier is configured to provide a compensation signal based on a dimming signal and a feedback signal. The minimum-off time control circuit is configured to provide a minimum-off time control signal to adjust a minimum-off time period of the first switch based on the compensation signal. The logic circuit is configured to provide the control signal based on the minimum-off time control signal.05-30-2013
20130093347Alternating Turn Off Timing Of A Fluorescent Lamp Starter Unit - A starter unit (for example, an RF-enabled and replaceable starter unit) has an ability both to turn on and to turn off a fluorescent lamp. The starter unit detects whether a ballast in the circuit with the fluorescent lamp is of a first type (for example, an L-type ballast) or is of a second type (for example, a C-type ballast). If the determination is that the ballast is of the first type, then the starter unit turns off the lamp in a first way (for example, using C-type timing and then using L-type timing alternatingly). If the determination is that the ballast is of the second type, then the starter unit turns off the lamp in a second way (for example, using only C-type timing). The same starter unit design is usable both in single-lamp fixtures and in multi-lamp fixtures where a mix of ballast types may be used.04-18-2013
20130093348METHOD, APPARATUS AND SYSTEM FOR CONTROLLING LIGHT SOURCE - A method, an apparatus and a system for controlling a light source are disclosed. The method comprises: receiving a dimming command, determining the dimming item specified by the dimming command (04-18-2013
20130099695METHOD FOR OPERATING A FLUORESCENT LAMP - A method for operating a fluorescent lamp which is connected to a series resonant circuit with a resonant circuit inductance and a resonant circuit capacitance. The method includes applying an excitation AC voltage at an excitation frequency to the series resonant circuit using a half bridge circuit, which has an output to which the series resonant circuit is coupled, and which has a first and a second switch which are alternately switched on and off on the basis of a frequency signal. A current flowing through the resonant circuit is monitored for the presence of a critical operating state. The switched-on times of the first and second switches are shortened in comparison to switched-on times which are predetermined by the frequency signal, upon detection of a critical operating state.04-25-2013
20130099692SYSTEM AND METHOD FOR FAST COMPENSATION PROGRAMMING OF PIXELS IN A DISPLAY - Circuits for programming a circuit with decreased programming time are provided. Such circuits include a storage device such as a capacitor for storing display information and for ensuring a driving device such as a driving transistor drives a light emitting device according to the display information. To increase programming time, the pixel circuits may be pre-charged or a biasing current may be applied to charge and/or discharge a data line and/or the driving device. Aspects of the present disclosure allow for the biasing current to drain partially through the storage device to allow the portion of the biasing current applied to the driving device to remain small while the data line discharges. Furthermore, the present disclosure provides display architectures and operation schemes for display arranged in segments each including a plurality of pixel circuits.04-25-2013
20130113387Power Supply For Lighting and Luminaire - According to one embodiment, a power supply for lighting includes an output element. The output element is connected between a power supply and a lighting load, and configured to be capable of being switched to a switching operation repeating an ON state and an OFF state and an ON continuation operation continuing the ON state.05-09-2013
20130181630DIGITAL LOAD CONTROL SYSTEM PROVIDING POWER AND COMMUNICATION VIA EXISTING POWER WIRING - A load control system comprises a load control device for controlling an electrical load receiving power from an AC power source, and a controller adapted to be coupled in series between the source and the load control device. The load control system may be installed without requiring any additional wires to be run, and is easily configured without the need for a computer or an advanced commissioning procedure. The load control device receives both power and communication over two wires, and the controller generates a phase-control voltage that has at least one timing edge in each half-cycle, and transmits digital messages by modulating a timing edge of the phase-control voltage relative to a reference edge. The controller may be operable to receive inputs from a plurality of different input devices, and the load control device may be operable to control a plurality of different loads.07-18-2013
20130127362EMERGENCY LIGHTING SYSTEMS AND METHODS FOR SOLID STATE LIGHTING APPARATUS - An emergency lighting module for providing emergency power to a solid state luminaire. The emergency lighting module includes a first input configured to receive a DC input voltage from the solid state luminaire, a second input configured to receive a status signal indicative of the status of an AC line voltage, and a first output configured to supply a DC output voltage to the solid state luminaire. The emergency lighting module is configured to supply the DC output voltage to the solid state luminaire in response to a reduction of the AC line voltage.05-23-2013
20130127361Step-Down Hysteretic Current LED Driver Implementing Frequency Regulation - A step-down hysteretic current LED driver circuit implements frequency regulation to adjust the hysteresis levels of a hysteretic comparator in the control circuit of the LED driver to keep the switching frequency of the inductor current constant. More specifically, the switching frequency of the inductor current is kept constant by increasing or decreasing the hysteresis window of the hysteretic comparator. In this manner, the switching frequency of the LED driver is kept constant or predictable. In one embodiment, the control circuit of the LED driver includes a frequency regulator to monitor the switching frequency and adjusts the hysteresis window accordingly to maintain a constant switching frequency.05-23-2013
20130141001METHOD AND APPARATUS FOR INCREASING DIMMING RANGE OF SOLID STATE LIGHTING FIXTURES - A system for controlling a level of light output by a solid state lighting load controlled by a dimmer includes a phase angle detector and a power converter. The phase angle detector is configured to detect a phase angle of the dimmer based on a rectified voltage from the dimmer and to determine a power control signal based on comparison of the detected phase angle with a predetermined first threshold. The power converter is configured to provide an output voltage to the solid state lighting load, the power converter operating in an open loop mode based on the rectified voltage from the dimmer when the detected phase angle is greater than the first threshold, and operating in a closed loop mode based on the rectified voltage from the dimmer and the determined power control signal from the detection circuit when the detected phase angle is less than the first threshold.06-06-2013
20130147385COMPENSATING LED CURRENT BY LED CHARACTERISTICS FOR LED DIMMING CONTROL - LED dimming control circuit and method compensate LED current or LED average current by LED characteristics to improve dimming efficiency and performance. LED characteristic related look-up tables are stored to provide compensation values, and input LED current setting information is compensated by the compensation values to generate corrected LED current setting information for determining LED brightness.06-13-2013
20080197786 IMPEDANCE CONTROLLED ELECTRONIC LAMP CIRCUIT - There is provided lamp ballast impedance controlled electronic lamp circuit, powered by a lamp ballast, for controlling a set of light emitting devices and being, comprising at least one connector, for connecting to the lamp ballast; and for receiving an AC signal; at least one filament control, associated with one of the at least one connector; a circuit for transforming the AC signal to a DC signal; a power convertor circuit; for receiving the DC signal and for processing the DC signal to provide a signal to power to the set of light emitting devices; a control and monitoring circuit; wherein the control and monitoring circuit monitors the DC signal and controls the impedance of either the at least one filament control or the power convertor circuit to control the set of light emitting devices.08-21-2008
20090026974FLUORESCENT TUBE POWER SUPPLY AND BACKLIGHT - A fluorescent tube power supply including an inverter power supply which outputs a DC voltage, and an inverter which converts an output of the inverter power supply to an AC; wherein a power stabilizing unit for stabilizing a power input to the inverter is arranged between the inverter power supply and the inverter; and a feedback control of the inverter power supply is performed based on an output of the power stabilizing unit. The power stabilizing unit detects a current flowing between the inverter power supply and the inverter, and the feedback control of the inverter power supply is performed based on the current.01-29-2009
20130147384DRIVING CIRCUIT AND ITS METHOD OF LIGHT EMITTING DIODE - A driving circuit comprising a control unit, a current control unit, a pulse width modulation control unit and a current driving unit is described. The control unit provides a first control signal and a second control signal. The current control unit is connected to the control unit, and converts a reference current into a plurality of current setting signals based on a data signal and the first control signal. The pulse width modulation control unit is connected to the control unit and outputs a pulse signal based on the data signal and the second control signal. The current driving unit is connected to the pulse width modulation control unit and drives the light emitting diode based on a driving current, wherein the control unit generates a continuous conduction time in a predetermined operation period based on the pulse signal and the current setting signals06-13-2013
20100289420LIGHTING DEVICE AND DISPLAY DEVICE - A lighting device (11-18-2010
20100308742Power Control System for Current Regulated Light Sources - A light emitting diode (LED) lighting system includes a PFC and output voltage controller and a LED lighting power system. The controller advantageously operates from an auxiliary voltage less than a link voltage generated by the LED lighting power system. The common reference voltage allows all the components of lighting system to work together. A power factor correction switch and an LED drive current switch are coupled to the common reference node and have control node-to-common node, absolute voltage that allows the controller to control the conductivity of the switches. The LED lighting system can utilize feed forward control to concurrently modify power demand by the LED lighting power system and power demand of one or more LEDs. The LED lighting system can utilize a common current sense device to provide a common feedback signal to the controller representing current in at least two of the LEDs.12-09-2010
20120274228ELECTRONIC CIRCUITS AND METHODS FOR DRIVING A DIODE LOAD - A circuit for driving an LED load with a controllable converter includes a control circuit configured to turn off the converter in response to a PWM signal having a first level and to turn on the converter in response to the PWM signal having a second level. A load disconnect switch coupled in series with the LED load is also controlled by the PWM signal so that the load disconnect switch is opened when the PWM signal turns off the converter to thereby open the load current path.11-01-2012
20100315016METHOD AND CIRCUIT ARRANGEMENT FOR REGULATING A LED CURRENT FLOWING THROUGH A LED CIRCUIT ARRANGEMENT, AND ASSOCIATED CIRCUIT COMPOSITION AND LIGHTING SYSTEM - The invention provides a method for regulating a LED current (ILED) flowing through a LED circuit arrangement at a mean LED current level. The method includes establishing an oscillating converter current(IL), establishing a first and a second current control indicator representative of a flow of a converter current (IL); regulating a peak and valley current level of the converter current in dependence on the first current control indicator; controlling a converter current period (T) of an oscillation of the converter current in dependence on the second current control indicator to be within a period control range (Tref) and feeding at least part of the converter current to the LED circuit arrangement. The invention also provides a circuit arrangement for regulating a LED current using the method, a LED driver IC using the circuit arrangement, a circuit composition with at least one LED and the circuit arrangement, and a lighting system with the circuit composition.12-16-2010
20100315015LAMP DRIVER FOR OPERATING A GAS DISCHARGE LAMP - A lamp driver circuit for operating a gas discharge lamp (La) is proposed, which comprises a switched mode power cc supply circuit (SMPS) and a first and a second output terminal (OT12-16-2010
20130154499CIRCUIT ARRANGEMENT AND METHOD FOR STARTING AND OPERATING A HIGH-PRESSURE DISCHARGE LAMP - A circuit arrangement may include: a half-bridge arrangement with a half-bridge center point, connected to an intermediate circuit voltage with a reference potential and a feed voltage potential; a lamp inductor connected at one end to the half-bridge center point; a starting stage connected to the other end of the lamp inductor and to the intermediate circuit voltage; a first switch connected between the reference potential and the starting stage; a series circuit of a first and a second capacitor connected to the intermediate circuit voltage; terminals for connecting a high-pressure discharge lamp, a first terminal being connected to the starting stage and a second terminal being connected to a node between the first and second capacitors; a two-port network, a first port of said two-port network connected to the starting stage and a second port of said two-port network connected to the node between the first and second capacitors.06-20-2013
20130154500METHOD AND APPARATUS FOR LED DRIVING AND DIMMING, AND ILLUMINATION SYSTEM - A method for driving an LED connected to a power switch is provided. The method may include: determining a duty cycle of a pulse sequence for controlling the power switch according to a present current and a predetermined operating current of the LED; generating the pulse sequence according to the duty cycle and according to at least one of a randomized period sequence and a randomized pulse position sequence; and controlling switching operation of the power switch by the pulse sequence, so as to drive the LED.06-20-2013
20130181632Flash Generating Device for LED and Flash Generating Method for LED - Provided is a flash generating device for an LED, which has a small energy loss and a small system area. A flash generating device (07-18-2013
20130187562DEVICE AND METHOD FOR AUTOMATICALLY DETECTING INSTALLED LAMP TYPE - An apparatus (07-25-2013
20120019159GAS-DISCHARGE LAMP CONTROLLER UTILIZING A NOVEL REHEATING FREQUENCY GENERATION MECHANISM - A gas-discharge lamp controller utilizing a novel preheating frequency generation mechanism, including: a resistance sensing means, used to generate a sensed voltage when coupled to an external series resistor-capacitor network, the external series resistor-capacitor network being biased between a first supply voltage and a reference ground; a sample and hold circuit, used to generate a sampled voltage of the sensed voltage under the control of a latch signal; and a mapping circuit, used to generate a control voltage according to a function of the sampled voltage.01-26-2012
20120019158Polarity-reversible dimming controller having function of switching light source - A polarity-reversible dimming controller having function of switching light source has a power supply module and a dimming control module. The dimming control module receives an external PWM dimming signal to control a feedback signal of the power supply module so as to dim or power on/off an LED lamp. The dimming control module has an output current switching circuit, a switch control circuit and a dimming control circuit. The output current switching circuit performs a PWM control over a current outputted from the power supply module by using the external PWM dimming signal to maintain chromacity of the LED lamp as a constant. The switch control circuit turns off the PWM controller to enter a standby mode for saving power once the PWM dimming signal exceeds a threshold value. As a full-wave rectification is performed on the PWM dimming signal, the polarity match issue upon assembling can be disregarded.01-26-2012
20130193865METHOD AND APPARATUS FOR DRIVING A LIGHT EMITTING DIODE STROBE - In one embodiment, the present invention is a method and apparatus for driving a light emitting diode strobe. One embodiment of a circuit for driving a current controlled light source includes an energy storage stage for storing a charge level and an energy delivery stage for drawing current from the energy storage stage and applying a fixed amount, of current to the current controlled light source.08-01-2013
20130193866METHOD AND APPARATUS FOR DETECTING PRESENCE OF DIMMER AND CONTROLLING POWER DELIVERED TO SOLID STATE LIGHTING LOAD - A system and method control an amount of power delivered by a power converter (08-01-2013
20120293088IGNITION APPARATUS - An ignition apparatus includes: sparking coil supplying a sparking plug with a high voltage; an energy supply device supplying the sparking coil with energy; a first switch disposed therebetween; and a control device controlling the first switch's conduction. The energy supply device has a DC power supply, a resonance coil connected to the DC power supply, a sparking capacitor connected to the resonance coil, and a second switch disposed between the sparking capacitor and an earth, and charges the sparking capacitor to have a voltage value larger than that of the DC power supply in absolute value by making the resonance coil and the sparking capacitor generate an LC resonance when the second and first switches are turned ON and OFF, respectively, according to an instruction from the control device whereas supplying the sparking coil with energy when the second and first switches are operated inversely according to another instruction.11-22-2012
20120043904DISCHARGE LAMP LIGHTING DEVICE, PROJECTOR, AND DRIVING METHOD OF DISCHARGE LAMP - In at least one embodiment of the disclosure, a discharge lamp lighting device includes a discharge lamp driving section that drives a discharge lamp and a control unit that controls the discharge lamp driving section. The control unit alternately performs a first-interval DC driving process and a first-interval AC driving process in a first interval, alternately performs a second-interval DC driving process and a second-interval AC driving process in a second interval other than the first interval, and changes a length of at least one of a period during which the first-interval DC driving process is performed and a period during which the second-interval DC driving process is performed so as to be shortened in a stepped manner within a predetermined sub-interval.02-23-2012
20130200815ENERGY STORAGE MEANS FOR LAST GASP / IMPEDANCE LIMITED APPLICATIONS - A voltage converter is coupled to an input voltage for boosting the voltage to a much higher level so as to take advantage of smaller capacitors due to the quadratic energy equation ½*CV̂2. The voltage converter has at least one boost converter having an inductive element coupled to the input voltage. A high voltage storage element is coupled to the inductive element. A switching circuit of the at least one boost converter transfers stored electrical energy in the inductive element to said storage element. The switching circuit allows for the combining of the stored electric energy of the storage element with the input voltage to illuminate a flash element, or provide an increased amount of current temporarily to the input for applications such as last gasp.08-08-2013
20130200816IGNITION SYSTEM - An ignition system is provided, which can restrict decreasing of constant-voltage duration of a spark plug and effectively prevents the occurrence of an accidental fire in an engine. A typical ignition system includes a secondary coil having one end connected to a positive side of a battery via a low-voltage side path and the other end connected to a center electrode via a connecting path which connects the secondary coil and the spark plug. A constant-voltage path having a grounded end is connected to the connecting path. A block diode is arranged between the secondary coil and a point where the constant-voltage path is connected with the connecting path. A Zener diode is disposed within the constant-voltage path. Each anode of the block diode and the Zener diode is mutually connected.08-08-2013
20120086351METHOD TO ENSURE BALLAST STARTING REGARDLESS OF HALF CYCLE INPUT - A ballast circuit (04-12-2012
20130207565ELECTROOPTICAL DEVICE - In an electrooptical device including an electrooptical modulating layer between a first substrate 08-15-2013
20130207564ELECTROOPTIC DEVICE, METHOD FOR DRIVING ELECTROOPTIC DEVICE AND ELECTRONIC APPARATUS - An electrooptic device has a data line, a pixel circuit and a driver circuit which drives the pixel circuit. The driver circuit has a first feeder line, a level shift circuit to be electrically coupled with the data line and a driving control circuit which provides the first feeder line with a first voltage or a second voltage and controls operations of the level shift circuit and the pixel circuit. The level shift circuit has a second holding capacitor and a switch section which switches over condition of a connection between the second holding capacitor and the first feeder line.08-15-2013

Patent applications in class Impedance or current regulator in the supply circuit