Entries |
Document | Title | Date |
20080252220 | SERIES WIRED LIGHT STRING WITH SHUNTS AND FLASHER BULBS FOR EXHIBITING A TWINKLING EFFECT - A circuit to cause the dimming and brightening of a series connected light string periodically by providing a unidirectional shunt and a flasher bulb in at least one of the sockets to intermittently cause the string to go to its dimmer state when the flasher bulb goes out and the full brightness to return when the flasher bulb comes back on. This shunt is preferably provided in the first light socket next to the AC plug. In another embodiment of the present invention, bidirectional shunts are provided in some of the sockets in an otherwise unidirectionally shunted series connected light string for the purpose of achieving random twinkle by inserting flasher bulbs in those sockets. The unidirectional shunts used in the present invention can be a diode array or a rectifier in series with a Zener diode in its Zener direction. The bidirectional shunts are devices which conduct current in both directions, such as back-to-back Zener diodes; metal oxide varistors; silicon trigger switches (STS devices); a diode array; or resistors. | 10-16-2008 |
20080258630 | Light String Lamp Bypass Device - A light string lamp bypass device is comprised of a plug and a conducting member. The plug is shaped and sized to releasably fit within a lamp socket of the light string. The conducting member is attached to the plug. It is shaped, sized and positioned upon the plug such that the conducting member is electrically connected to the socket terminals, is positioned below the top surface of the plug and is positioned between the socket terminals when the plug is inserted into the lamp socket. The impedance of the conducting member substantially matches the impedance of an operating lamp within a lamp socket of the light string. A section of a light string may be darkened by replacing its lamps with the device. A typical use is for the darkening of a section of a light string connecting two decorated bushes. | 10-23-2008 |
20090091263 | CAPACITOR SHUNTED LED LIGHT STRING - A series connected LED light string using capacitors as shunts. The shunts are implemented by inserting a capacitor—for example a low breakdown voltage chip capacitor—in every light socket, or internally within each LED. The capacitive shunt continues current in the light string in the event an LED fails by opening electrically—the capacitor shorts out, thus, keeping the string of lights illuminated. The shunt capacitor across the LED also helps filter the pulsating DC voltage to the bulbs and reduces annoying flicker. | 04-09-2009 |
20090128042 | GOLD OR SILVER PLATED WIRE LEADS ON CHRISTMAS LIGHTS - The electrical wire leads of miniature lights or LED's in a series-wired Christmas light string are gold or silver plated to resist corrosion. The wire leads of any shunt components used in the sockets of the light string can also be plated for corrosion resistance. | 05-21-2009 |
20090189529 | SEMICONDUCTOR LIGHT EMITTING CIRCUITS INCLUDING LIGHT EMITTING DIODES AND SEMICONDUCTOR SHUNT DEVICES - Semiconductor light emitting circuits include semiconductor light emitting diodes that are serially connected between a pair of input terminals. Four layer semiconductor devices, such as Shockley diodes and/or thyristors are also provided, a respective one of which is connected across a respective one of the semiconductor light emitting diodes. The four layer semiconductor devices can allow a string of light emitting diodes to continue to be lit if one light emitting diode fails. | 07-30-2009 |
20090195163 | Single LED String Lighting - A solid state lighting unit constituted of: a control circuitry; a single string of light emitting diodes, the single string constituted of a plurality of sections each comprising a plurality of light emitting diodes; and a plurality of bypass paths each responsive to the control circuitry, each of the plurality of bypass paths arranged to provide bypass to a particular one of the plurality of sections, wherein the control circuitry is operative to identify an open circuit condition of a particular one of the plurality of sections, and activate the bypass path arranged to bypass the open circuit section, thereby providing light through sections not exhibiting an open circuit condition. | 08-06-2009 |
20100123399 | LED lighting system with bypass circuit for failed LED - A bypass circuit is provided for each LED in a series to permit continued operation with reduced lighting in the event of an LED failure. The bypass circuit is provided in parallel to the LED and comprises a Zener Diode provided in parallel to a thyristor. Upon LED failure, the voltage across the Zener Diode is increased thereby triggering the thyristor which is maintained in a triggered mode as long as current flows through the series circuit. | 05-20-2010 |
20100134018 | LED STRING DRIVER WITH LIGHT INTENSITY RESPONSIVE TO INPUT VOLTAGE - A driving arrangement for a plurality of light emitting diodes (LEDs), the driving arrangement constituted of: a plurality of serially connected first LEDs coupled to a source voltage; a plurality of first electronically controlled switches, each associated with a particular one of the plurality of serially connected first LEDs and arranged to provide, when closed, a bypass current path for the associated first LED; and a control circuitry coupled to a control terminal of each of the plurality of first electronically controlled switches, the control circuitry operative to close a number of the plurality of first electronic switches, the number responsive to a voltage level of the source voltage. | 06-03-2010 |
20100188002 | OVERVOLTAGE PROTECTION FOR CURRENT LIMITING CIRCUITS IN LED APPLICATIONS - An apparatus to provide overvoltage protection is shown. The apparatus comprises a boost converter (having an output node, a sensing network, and an impedance network) and a zener diode. The zener diode is coupled to the output node and to the sensing network. The breakdown value of the zener diode is selected to be greater than a desired voltage drop across a load when the load is coupled to the output node, and the zener diode creates an overcurrent fault in the boost converter when the voltage at the output node is greater than its breakdown value. | 07-29-2010 |
20110031888 | METHODS AND APPARATUS FOR CONTROLLING RESPECTIVE LOAD CURRENTS OF MULTIPLE SERIES-CONNECTED LOADS - A lighting apparatus ( | 02-10-2011 |
20110057569 | ZENER DIODE PROTECTION NETWORK IN SUBMOUNT FOR LEDS CONNECTED IN SERIES - A transient voltage suppressor circuit is disclosed for a plurality (N) of LEDs connected in series. Only one zener diode is created for connection to each node between LEDs, and a pair of zener diodes (the “end” zener diodes) are connected to the two pins (anode and cathode pads) of the series string. Therefore, only N+1 zener diodes are used. The end zener diodes (Q | 03-10-2011 |
20110062872 | Adaptive Switch Mode LED Driver - An adaptive switch mode LED driver provides an intelligent approach to driving multiple strings of LEDs. The LED driver determines an optimal current level for each LED channel from a limited set of allowed currents. The LDO driver then determines a PWM duty cycle for driving the LEDs in each LED channel to provide precise brightness control over the LED channels. Beneficially, the LED driver minimizes the power dissipation in the LDO circuits driving each LED string, while also ensuring that the currents in each LED string are maintained within a limited range. A sample and hold LDO allows PWM control over extreme duty cycles with very fast dynamic response. Furthermore, fault protection circuitry ensures fault-free startup and operation of the LED driver. | 03-17-2011 |
20110109231 | LED CURRENT CONTROL CIRCUIT, CURRENT BALANCER AND DRIVING APPARATUS - An LED current control circuit including a current adjusting unit, a detecting unit, and a current control unit is provided. The current adjusting unit has a current control end coupled to an LED string for determining an amount of current flowing through the LED string according to a current control signal. The detecting unit detects the current control end and determines whether to generate a protecting signal according to a protecting voltage value. The current control unit generates the current control signal to control the amount of current flowing through the LED string of and determines whether to stop the current flowing through the LED string according to the protecting signal. | 05-12-2011 |
20110199003 | LIGHT-EMITTING DIODE DRIVING APPARATUS AND LIGHT-EMITTING DIODE LIGHTING CONTROLLING METHOD - A LED driving apparatus includes a rectifying circuit | 08-18-2011 |
20110221346 | CIRCUITS AND METHODS FOR DRIVING LIGHT SOURCES - Embodiments in accordance with the present invention provide circuits and methods for driving light sources, e.g., a light-emitting diode (LED) light source. In one embodiment, a printed circuit board (PCB) includes a bridge rectifier rectifying an AC voltage to a rectified AC voltage, an LED light source, and a first switch coupled to the LED light source in series controlling a current through the LED light source according to a predetermined current reference. The LED light source and the first switch coupled in series receive the rectified AC voltage while the first switch is controlled linearly. | 09-15-2011 |
20110227484 | AC LED lamp involving an LED string having separately shortable sections - An LED lamp includes a rectifier, an integrated circuit and a string of series-connected LEDs. The lamp receives an incoming AC signal such that a rectified version of the signal is present across the LED string. The integrated circuit includes a plurality of power switches. Each power switch is coupled so that it can separately and selectably short out a corresponding one of several groups of LEDs in the string. As the voltage across the string increases the integrated circuit controls the power switches such that the number of LEDs through which current flows increases, whereas as the voltage across the string decreases the integrated circuit controls the power switches such that the number of LEDs through which current flows decreases. LED string current flow is controlled and regulated to provide superior efficiency, reliability, anti-flicker, regulation against line voltage variations, power factor correction, and lamp over-voltage, over-current, and over-temperature protection. | 09-22-2011 |
20110316425 | METHOD FOR CONTROLLING LIGHT SOURCE DRIVING CIRCUIT - A method for controlling a light source driving circuit is provided. The method includes driving a plurality of serially-connected light sources, and measuring a working parameter of the light sources; shorting the light sources sequentially to find out at least a failed light source, when the working parameter is not measured; and remaining shorting the failed light source, and regulating a brightness of the light sources without having the failed light source according to a newest working parameter. | 12-29-2011 |
20120025713 | System using shunt circuits to selectively bypass open loads - According to an exemplary embodiment, a shunt circuit includes a floating shunt switch configured to bypass at least one load, for example at least one LED, among a plurality of series-connected loads, such as a plurality of series-connected LEDs in a lighting system, responsive to a high-side control signal. The at least one load has terminals connected across the shunt circuit. The shunt circuit further includes a high-voltage level-shift up circuit configured to shift a low-side control signal up to the high-side control signal using a voltage of at least one of the terminals of the at least one load. The floating shunt switch can be configured to bypass the at least one load responsive to a failure of the at least one load. | 02-02-2012 |
20120074846 | Semiconductor Component and Method - A semiconductor component and a method for manufacturing the semiconductor component, wherein the semiconductor component includes one or more transient voltage suppression structures. In an embodiment, the semiconductor component may include an over-voltage detection circuit, an over-current detection circuit, an over-temperature detection circuit, an ESD protection circuit, or combinations of these circuits. | 03-29-2012 |
20120081008 | CONTROL CIRCUIT MODULE OF LIGHT-EMITTING DIODE LAMP - The present invention relates to a control circuit module of light-emitting diode (LED) lamp, which comprises: a AC to DC element, for transferring mains AC power to DC power; a plurality of groups of LED; a plurality of switches, corresponding to the number of the groups of LED, for controlling to turn on/off the each group; a linear voltage regulator, for cutting the DC power from the AC to DC element to a plurality of voltage sections; a switch selector, for selecting to open/close the switches according to the voltage sections from the linear voltage regulator; a current selector, for capturing available current sections from the voltage sections of the linear voltage regulator; and a LED current setup device, for controlling the current sections to open/close the plurality of switches by a user according to the LED current setup device and the current selector. | 04-05-2012 |
20120081009 | Apparatus, Method and System for Providing AC Line Power to Lighting Devices - An apparatus, method and system are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). An exemplary apparatus comprises: a plurality of LEDs coupled in series to form a plurality of segments of LEDs; first and second current regulators; a current sensor; and a controller to monitor a current level through a series LED current path, and to provide for first or second segments of LEDs to be in or out of the series LED current path at different current levels. A voltage regulator is also utilized to provide a voltage during a zero-crossing interval of the AC voltage. In an exemplary embodiment, first and second segments of LEDs are both in the series LED current path regulated at a lower current level compared to when only the first segment of LEDs is in the series LED current path. | 04-05-2012 |
20120104952 | DRIVING CIRCUIT FOR CASCADE LIGHT EMITTING DIODES - The driving circuit includes a power module, a Plurality of LED modules, and a constant current component. Each LED module includes a bypass circuit and at least one light emitting diode. The light emitting diode is serially connected between a first end and a second end of the bypass circuit. The first end of each bypass circuit is coupled to the power module or a third end of an adjacent upstream bypass circuit for serially connecting the constant current component electrically, thereby achieving the illumination of different total numbers of LED units in accordance with various voltage changes, and cascade light emitting diodes having increased power efficiency. | 05-03-2012 |
20120119650 | ACTIVE CONSTANT POWER SUPPLY APPARATUS - Disclosed is an active constant power supply apparatus, which rectifies power having various intensities and frequencies without using a high capacity condenser for a smoothing circuit which degrades the power factor of a circuit, and supplies constant power to a load. The active constant power supply apparatus includes an AC power supplier for supplying AC power; a rectifying circuit which receives AC power from the AC power supply unit and rectifies the received power; a driving coil connected in series to the load receiving power from the rectifying circuit; a power switch which switches the current passing through the driving coil and the load on/off; a pulse-type driving signal generator connected to a gate terminal of the power switch to control the switching on/off operation of the power switch; a turn-off decider which generates a turn-off signal when the current flowing along the driving coil has a value higher than the designed value, so as to turn off the power switch; and a pulse width controller which measures the control period ranging from the switch-on time of the driving signal generator to the switch-off time of the turn-off decider, and controls the driving pulse width of the driving signal generator such that the driving pulse width coincides with the control period. | 05-17-2012 |
20120119651 | LED LIGHTING DEVICE AND LED LIGHTING EQUIPMENT - In one embodiment, a lighting device includes an LED lighting circuit and an LED load constituted by a plurality of parallel circuits formed by connecting a plurality of LED elements in parallel, and a series circuit formed by connecting the parallel circuits. The series circuit is connected with an output terminal of the lighting device. In case one LED element becomes open fault mode in one of the parallel circuit, the other LED elements continue lighting. In case two or more LED elements become the open fault mode, the other LED elements also become the open fault mode, and all the LED elements turn off. | 05-17-2012 |
20120126703 | DRIVING APPARATUS AND DRIVING METHOD OF LED DEVICE - A driving apparatus of an LED device is provided. The LED device includes a plurality of LED channels, and each LED channel includes a plurality of LEDs connected in series. A power converter has an output terminal connected to a first terminal of each LED channel, and converts an input voltage into an output voltage to output the output voltage to the output terminal. A plurality of current controllers correspond to the plurality of LED channels, respectively. Each current controller is connected to a second terminal of a corresponding LED channel, and controls a current of the corresponding LED channel. The voltage sensor outputs a sensed voltage corresponding to the output voltage of the output terminal. The fault controller determines whether to stop operation of the power converter by comparing the sensed voltage with a reference voltage. | 05-24-2012 |
20120133286 | LIGHTING APPARATUS - Provided is a lighting apparatus which supplies current from direct-current power supplies to light-emitting diodes, detects current flowing through the light-emitting diodes, and performs on/off control of the direct-current power supplies. The lighting apparatus includes a resistance connected between the direct-current power supplies and a fixed potential terminal, a voltage dividing circuit for dividing a predetermined voltage, a PWM control circuit and FET for variably controlling a dividing ratio of the voltage dividing circuit by PWM control based on a duty ratio in accordance with an operation for setting brightness, and a comparison circuit for comparing a voltage associated with a both-end voltage of the resistance with an output voltage of the voltage dividing circuit. The lighting apparatus performs on/off control of the direct-current power supplies in accordance with the comparison result obtained by the comparison circuit. | 05-31-2012 |
20120139420 | LIGHT EMITTING DIODE DRIVING SYSTEM - A light emitting diode (LED) driving system comprises a plurality of current limitation circuits and a plurality of over-voltage protection circuits to driving a plurality of LED strings. Each of the current limitation circuits comprises a first switch comprising a control pole receiving a reference voltage, a first pole correspondingly connected to a LED string, and a second pole connected to the ground via a first resistor and a second switch comprising a control pole connected to the second pole of the first switch via a second resistor, a first pole receiving the reference voltage, and a second pole grounded. Each of the over-voltage protection circuits comprises a zener diode, a third switch and a first capacitor. | 06-07-2012 |
20120139421 | INTEGRATED CIRCUITS, CONTROL METHODS AND LIGHTING SYSTEMS - Integrated circuits, control methods, and related lighting systems are provided. One integrated circuit controls the currents flowing through light-emitting-diode chains, each having several light emitting diodes forward-connected between a main cathode and a main anode while all the main anodes are connected to a power node. The integrated circuit has a short detection node, a constant current source, a voltage clamping circuit, and a short-circuit comparator. The short detection node detects the highest cathode voltage of the main cathodes. The constant current source provides a constant current to the short detection node. While the light-emitting-diode chains are unlit, the voltage clamping circuit clamps the short detection node at a predetermined voltage. When the voltage of the short detection node exceeds a threshold voltage, the short-circuit comparator asserts a fault signal, indicating a short circuit of a light emitting diode. | 06-07-2012 |
20120146514 | LIGHT EMITTING DIODE DRIVER HAVNG CASCODE STRUCTURE - A driver circuit for driving light emitting diodes (LEDs). The driver circuit includes: a string of LEDs divided into n groups, the n groups of LEDs being electrically connected to each other in series, a downstream end of group m−1 being electrically connected to the upstream end of group m, where m is a positive number equal to or less than n. The driver circuit also includes a power source coupled to an upstream end of group 1 and operative to provide an input voltage and a plurality of current regulating circuits, each of the current regulating circuits being coupled to the downstream end of a corresponding group at one end and coupled to a ground at the other end and including a sensor amplifier and a cascode having first and second transistors. | 06-14-2012 |
20120153833 | Controlling Current Flowing Through LEDs in a LED Lighting Fixture - An alternating current (“AC”)-powered light emitting diode (“LED”) driver is described herein for driving one or more arrays of series-connected LEDs. The LED driver includes a first transistor that includes a collector-emitter path connected in series with at least one LED of an array of series-connected LEDs. The LED driver also includes a second transistor configured to selectively activate the first transistor based on a level of current through the array of series-connected LEDs. The array of series-connected LEDs has a turn-on voltage. | 06-21-2012 |
20120153834 | MULTICHANNEL LIGHTING UNIT AND DRIVER FOR SUPPLYING CURRENT TO LIGHT SOURCES IN MULTICHANNEL LIGHTING UNIT - A lighting unit includes at least two channels of light sources, and a driver for the light sources. The driver includes a DC/DC converter and a control arrangement for controlling the current supplied to at least one of the two channels in response to a control signal produced by the DC/DC converter. Beneficially, a feedback loop controls a switching device in the DC/DC converter to maintain the light level produced by the light sources at a desired level regardless of changes in the supply voltage and the load. | 06-21-2012 |
20120161637 | Organic Light Emitting Diode Display - An organic light emitting diode (OLED) display includes a display panel including data lines, scan lines crossing the data lines, and light emitting cells, which are arranged in a matrix form and each include an OLED, and a panel driving circuit, which reduces a reference voltage applied to an anode of the OLED to a ground level voltage in a sleep-out mode and adjusts the reference voltage at a voltage level greater than the ground level voltage. The reference voltage is held at a voltage level greater than the ground level voltage in a normal driving mode. | 06-28-2012 |
20120161638 | LED DRIVE CIRCUIT - An LED drive circuit that can increase the amount of light with a compact structure. This circuit includes series-connected LEDs, first and second DC power supplies connected in series so as to apply a forward bias to the LEDs, a coil that is series-connected with the LEDs and can accumulate energy from current generated by the DC power supplies, a rectifying element whose cathode is connected between the DC power supplies, a transfer switching element connected to the anode of the rectifying element, and a control apparatus for controlling the transfer switching element. A first closed circuit is formed by the LEDs, the DC power supplies, and the coil when the transfer switching element is switched on by the control apparatus, and a second closed circuit is formed by the LEDs, the second DC power supply, the coil, and the rectifying element when the transfer switching element is switched off. | 06-28-2012 |
20120161639 | INTEGRATED CIRCUITS, CONTROL METHODS AND LIGHTING SYSTEMS - An integrated circuit is capable of controlling current through several light-emitting diode (LED) chains, each having several LEDs forward-connected in series between a major anode and a major cathode. Each major anode is coupled to a power node. The integrated circuit has several driving circuits, a detection node, a comparator, and a logic controller. The driving circuits can light the LED chains, respectively. Detection voltage at the detection node corresponds to voltage at one of the major cathodes. The comparator asserts a ready signal when the detection voltage exceeds a reference voltage. Receiving a dimming signal and the ready signal, if the dimming signal is asserted and the ready signal has been asserted, the logic controller enables the driving circuits to light the LED chains. | 06-28-2012 |
20120176037 | LED LIGHTING APPARATUS EQUIPPED WITH HIGH-EFFICIENCY POWER SUPPLY - Disclosed is an LED lighting apparatus equipped with a high-efficiency power supply, capable of representing high power efficiency even in a low-power LED lighting apparatus by recycling a surplus voltage to charge a condenser, which supplies power to the controller, with the surplus voltage if the surplus voltage is generated from an LED acting as a load after a rectified voltage supplied to the LED has been consumed in the LED according to a design value. | 07-12-2012 |
20120176038 | LIGHT EMITTING DIODE EMITTING DEVICE - The present invention relates to an LED emitting device. | 07-12-2012 |
20120194078 | LED BACKLIGHT DRIVER SYSTEM AND ASSOCIATED METHOD OF OPERATION - The embodiments of the present circuit and method disclose a light-emitting diode (LED) driver system. The LED driver system may comprise an isolated converter and a DC/DC converter. The isolated converter may be coupled to a first input signal, and may provide a LED current and a bus voltage. The isolated converter may be configured to regulate the LED current and the bus voltage separately in accordance with a dimming signal. The DC/DC converter may comprise an input coupled to the bus voltage. | 08-02-2012 |
20120206047 | CURRENT SENSING TRANSISTOR LADDER DRIVER FOR LIGHT EMITTING DIODES - Ladder network circuits for controlling operation of light emitting diodes (LEDS) based upon current sensing. The circuits include a number of light sections connected in series. Each light section includes an LED device comprising at least one LED junction, a current sensing feedback circuit coupled to the LED device, and a switch coupled to the current sensing feedback circuit and the LED device for controlling activation and current through the LED device. The current sensing feedback circuit is configured to generate a sensing signal indicative of current through the LED device, generate a feedback signal based upon the sensing signal, and provide the feedback signal to the switch. | 08-16-2012 |
20120206048 | LED DEVICE WITH VOLTAGE-LIMITING UNIT AND SHUNT CURRENT-LIMITING RESISTANCE - The present invention provides a LED device with the voltage-limiting unit and the shunt current-limiting resistance wherein a voltage-limiting unit is connected in series with a current-limiting resistance then connected in parallel with two ends of a LED, so that to constitute the light-emitting unit, thereby when plural of the light-emitting units are connected in series (including connected in series and parallel), the current of LED loaded with higher end voltage passing through the voltage-limiting unit is prevented to be overly high when subject to abnormal high voltage. | 08-16-2012 |
20120212138 | ILLUMINATION CONTROL THROUGH SELECTIVE ACTIVATION AND DE-ACTIVATION OF LIGHTING ELEMENTS - In various embodiments, an illumination system includes multiple light-emitting strings that are selectively activated or deactivated to regulate an overall output of the array. | 08-23-2012 |
20120217878 | CIRCUITS AND METHODS FOR DRIVING LIGHT SOURCES - In one embodiment, a driving circuit includes an AC/DC converter which converts an AC voltage to a DC voltage and a DC/DC linear regulator which regulates a current through, e.g., an LED light source, according to a first current reference if a monitoring signal indicating the DC voltage is within a predetermined range, and regulates the current according to a second current reference less than the first current reference if the monitoring signal is beyond the predetermined range. In another embodiment, a controller controlling power to an LED light source turns on a first plurality of LEDs and turns off a second plurality of LEDs if a monitoring signal indicative of a DC voltage received by the LED light source is within a predetermined range, and turns on both first and second plurality of LEDs if the monitoring signal is beyond the predetermined range. | 08-30-2012 |
20120229030 | DIRECTLY DRIVEN HIGH EFFICIENCY LED CIRCUIT - A system for directly driving light emitting diodes (LEDs). A string of LEDs is coupled across an input voltage and includes a plurality of separate groups of LEDs. Each of a plurality of switches is coupled in parallel with an associated one of the groups of LEDs for controlling current flow through the associated group of LEDs in response to a control signal from a controller circuit. A switch protection circuit is associated with at least one of the switches. The switch protection circuit is configured to place the switch into a conducting state in the event of failure of an LED in the associated group of LEDs. | 09-13-2012 |
20120229031 | Converting Controller - A converting controller comprises a power pin, a ground pin, at least one input pin, at least one output pin, at least one set pin and a failure generating circuit. The power pin is adapted to be coupled with a power source to receive electric power for operation, and the ground pin is adapted to be grounded. The input pin is adapted to receive a corresponding input signal and the output pin is used to output a corresponding output signal. The set pin is adapted to set a corresponding operating parameter of the converting controller. The failure generating circuit is coupled with and uses one of the input pin and the set pin as a protection output pin. The failure generating circuit modulates the level of the protection output pin to be a protection logic level when the converting controller is under a protection state. | 09-13-2012 |
20120248986 | Solid state light AC line voltage interface with current and voltage limiting - An analog electronic circuit for driving a string of LEDs including input terminals for accepting connection to AC voltage, a current regulation circuit operatively coupled to receive an AC voltage from the input terminals and to provide an output for connection to drive the string of LEDs. Included is a current regulation circuit configured to limit the current flow through the string of LEDs on a half-cycle basis to a predetermined value. Also disclosed is an over voltage circuit configured to switch off electrical connection between the AC voltage and the string of LEDs upon the AC reaching a predetermined high voltage value on a half-cycle basis. | 10-04-2012 |
20120262068 | LED DRIVING CIRCUIT - An LED (light emitting diode) driving circuit includes a rectifying circuit, an LED module, a voltage dropping circuit connected to the LED module, a voltage detecting circuit connected between the voltage dropping circuit and the LED module, and an integrated circuit. The integrated circuit includes a pulse-width modulation (PWM) control module providing PWM waves, an overcurrent protection (OCP) module, an overvoltage protection (OVP) module, and a frequency control module. The OCP module detects the working current of the LED module, and the OVP module detects the working voltage. The frequency control module adjust the duty cycle of the PWM waves according to the results of comparisons made by the OCP module and the OVP module against reference levels, to adjust the working current of the LED module. | 10-18-2012 |
20120268012 | CIRCUIT FOR DETECTION AND CONTROL OF LED STRING OPERATION - A circuit is disclosed for determining which of a multiplicity of LED strings in an illumination system has a fault. A group of circuits determines the maximum, minimum, midpoint between maximum and minimum, and average voltage of the group of LED string voltages in use, and examines the statistical properties of the LED string voltages. Comparators are used to find the strings which have the highest and lowest operating voltages, and to compare the midpoint and average voltages to determine whether the highest or lowest voltage string is responsible for causing a fault in the illumination system operation. Memory means are used to keep the said determined string turned off to prevent faulty operation. | 10-25-2012 |
20120280621 | Temperature Responsive Control For Lighting Apparatus Including Light Emitting Devices Providing Different Chromaticities And Related Methods - A lighting apparatus may include a plurality of light emitting devices, a temperature sensor, and a compensation circuit. The plurality of light emitting devices may include a first light emitting device configured to emit light having a first chromaticity, a second light emitting device configured to emit light having a second chromaticity different than the first chromaticity, and a third light emitting device configured to emit light having the second chromaticity. Moreover, the first, second, and third light emitting devices may be electrically coupled in series. The temperature sensor may be configured to generate a temperature sense signal responsive to heat generated by at least one of the plurality of light emitting devices. The compensation circuit may be coupled to the third light emitting device, with the compensation circuit being configured to vary a level of electrical current through the third light emitting device relative to the electrical current through the first and second light emitting devices responsive to the temperature sense signal. Related methods are also discussed. | 11-08-2012 |
20120280622 | LIGHT EMITTING DIODE DRIVER - A driver circuit for driving light emitting diodes (LEDs). The driver circuit includes: a string of LEDs divided into n groups, the n groups of LEDs being electrically connected to each other in series, a downstream end of group m-1 being electrically connected to the upstream end of group m, where m is a positive number equal to or less than n. The driver circuit also includes a plurality of current regulating circuits, each of the current regulating circuits being coupled to the downstream end of a corresponding group at one end and coupled to the ground at the other end and including a sensor amplifier and a cascode having first and second transistors, each sensor amplifier being coupled to a different voltage source for providing a different reference voltage thereto. | 11-08-2012 |
20120286668 | LED LIGHTING SYSTEM, LED LAMP, AND ILLUMINATION SYSTEM FOR LED - The object of the present invention is to provide a LED illumination system which does not cause heat generation and damage, even when a straight-tube fluorescent lamp is mistakenly fitted into a straight-tube fluorescent lamp luminaire in which the fluorescent lamp ballast has been replaced with a LED lighting device. | 11-15-2012 |
20120299484 | CONSTANT CURRENT DRIVING APPARATUS FOR LEDS - An LED constant current driving apparatus includes a power supply module; an LED module comprising one or more LEDs connected in serial, the LED module that is luminous by the power supplied by the power supply module; a current detection module connected to an output terminal of the LED module, to detect a current flowing to the LED module; an error amplification module configured to compare the current signal detected by the current detection module to a first preset signal and to amplify and output an error signal base on the result of the comparison; and a plurality of sequential driving control modules connected to the one or more LEDs provided in the LED module in serial, to compare the error signal amplified and outputted by the error amplification module to a second preset reference and to control luminosity and off driving of each LED of the LED module. | 11-29-2012 |
20120306375 | SYSTEMS AND METHODS FOR CONTROLLING SOLID STATE LIGHTING DEVICES AND LIGHTING APPARATUS INCORPORATING SUCH SYSTEMS AND/OR METHODS - A lighting apparatus includes at least two sets of light-emitting devices with overlapping spectra and different chromaticities, such as two sets of blue-shifted yellow (BSY) LEDs producing outputs with different yellow content. The devices may be selectively controlled, e.g., by using selective current bypass circuits, to provide a desired color temperature or other visual performance in response to a dimming control input such that, for example, a light output approximating that of an incandescent lamp may be achieved. | 12-06-2012 |
20120319587 | LIGHT EMITTING DIODE DRIVER CIRCUIT - The present teachings provide a device and method of regulating current flow across an array of emitting diodes (LEDs) for the purpose of illumination. The device has a power supply (vext) connected to an LED array. The LED array is connected to a current foldback element, a current limitation element, a current sensing element, and a current switch. Current through the array of light emitting diodes achieves an upper current level, the current sensing element signals activation of the current limitation element, said current limitation element maintains current through the array of light emitting diodes at approximately the upper control limit. | 12-20-2012 |
20130015768 | HIGH VOLTAGE LED AND DRIVERAANM ROBERTS; Bruce RichardAACI Mentor-on-the-LakeAAST OHAACO USAAGP ROBERTS; Bruce Richard Mentor-on-the-Lake OH USAANM Nerone; LouisAACI BrecksvilleAAST OHAACO USAAGP Nerone; Louis Brecksville OH US - A method and apparatus for providing illumination by driving LEDs using a high-voltage driver, and more specifically a method and apparatus for using a simplified boost circuit connected to an AC mains to provide a higher voltage DC driving voltage to the LED array. | 01-17-2013 |
20130020945 | LED DRIVER AND THE METHOD THEREOF - A LED driver comprising: a power switch; a transformer comprising a primary winding coupled to the power switch, a secondary winding and a third winding; a current sense circuit configured to sense a current flowing through the power switch and generates a current sense signal; a zero cross detecting circuit configured to detect a current flowing through the secondary winding, and generates a zero cross detecting signal; a compensation circuit configured to compensate the current sense signal based on the current flowing through the third winding; a control circuit configured to receive the compensated current sense signal and the zero cross detecting signal, and wherein the control circuit generates a control signal to control the power switch. | 01-24-2013 |
20130026925 | Solid State Lighting Apparatus and Methods Using Integrated Driver Circuitry - A lighting apparatus includes a first substrate including a switching circuit, the switching circuit including a first port, a second port and a current control circuit configured to generate a current at the second port of the current control circuit responsive to a varying voltage at the first port. The apparatus further includes a second substrate mounted on the first substrate and including at least two LEDs electrically coupled to the second port of the current control circuit of the first substrate. | 01-31-2013 |
20130026926 | BACKLIGHT UNITS AND CURRENT CONTROL METHODS THEREOF - A backlight unit including: at least one light emitting diode (“LED”) string having an anode, which receives a string current, and a chassis-grounded cathode; and a current source control unit which receives a driving current and outputs the string current to the at least one LED string, where the current source control unit senses the driving current and compensates for the string current based on the sensed driving current and a reference voltage. | 01-31-2013 |
20130038213 | LED EMITTING DEVICE AND DRIVING METHOD THEREOF - The present invention relates to an LED emitting device and a driving method thereof. The LED emitting device receives an input voltage and supplies a power supply voltage needed for operating an LED channel according to a switching operation of a power switch. The LED emitting device controls the power supply and also controls a load switch between the LED channel and an output voltage. The LED emitting device determines the LED channel to be short circuited when the output voltage is reduced to a predetermined threshold voltage during a predetermined short circuit sense period starting from the time when the output voltage reaches a regulated voltage before the LED channel is dimmed. During the short circuit sense period, the power supply is stopped and the load switch is turned on. | 02-14-2013 |
20130043791 | UNLIT LED CIRCUIT BYPASS ELEMENT WITH SYSTEM AND METHOD THEREFOR - A lighting system and protection means are disclosed. In particular, a Zener diode with pre-selected characteristics is used in parallel with an LED such that current will continue to flow through the circuit in case of LED failure. This adaptation in turn may be used in a series string combination. | 02-21-2013 |
20130049599 | Driver Circuit for Efficiently Driving a Large Number of LEDs - A circuit can be used for controlling a plurality of LEDs coupled in series. A switching converter operates as a current source coupled to the plurality of LEDs to provide a constant load current thereto. The switching converter includes an inductor coupled in series with the plurality of LEDs such that the same load current flows through the inductor and the plurality of LEDs. No substantial capacitance is coupled between the inductor and the plurality of LEDs. A floating driver circuit is coupled in parallel with each individual LED of the plurality of LEDs. The floating driver circuit is configured to fully or partially take over the load current thereby bypassing the respective LED in accordance with a respective modulated input signal to control the intensity of the light emitted by the LED. | 02-28-2013 |
20130049600 | LIGHTING DEVICE AND METHOD OF CONTROLLING LIGHT EMITTED THEREBY - A lighting device and a method of controlling a light emitted thereby are disclosed. A lighting device including light emitting units configured of a plurality of light emitting diodes connected with each other in series according to the present invention may include a rectifier unit configured to rectify an alternation current voltage to supply the rectified voltage to each of the light emitting units, a control unit configured to control on and off of each light emitting unit according to the input voltage and light emitting units configured to be on and off based on the control of the control unit, wherein a first light emitting unit and a second light emitting unit are connected with each other in series, and the first light emitting unit and a third light emitting unit are connected with each other in parallel. | 02-28-2013 |
20130069536 | SOLID-STATE LIGHTING APPARATUS AND METHODS USING CURRENT DIVERSION CONTROLLED BY LIGHTING DEVICE BIAS STATES - A lighting apparatus includes a string of light emitting diode (LED) sets coupled in series, each set including at least one LED. The apparatus further includes a plurality of current diversion circuits, respective ones of which are coupled to respective nodes of the string and configured to operate responsive to bias state transitions of respective ones of the LED sets. In some embodiments, a first one of the current diversion circuits is configured to conduct current via a first one of the LED sets and is configured to be turned off responsive to current through a second one of the LED sets. The first one of the current diversion circuits may be configured to conduct current responsive to a forward biasing of the first one of the LED sets and the second one of the current diversion circuit may be configured to conduct current responsive to a forward biasing of a second one of the LED sets. | 03-21-2013 |
20130076247 | ILLUMINATING APPARATUS CAPABLE OF DETECTING POWER SUPPLY AND METHOD USING THE SAME - An illuminating apparatus is disclosed. The illuminating apparatus includes a detecting unit, an illuminating unit, and a control unit. The illuminating unit includes multiple illuminating sets and a switching unit for adjusting a connection relationship among the illuminating sets. The detecting unit is for detecting an inputted power supply received by the illuminating unit while the control unit is coupled to the detecting unit and the switching unit. The control unit based on a detected inputted power supply controls the switching unit according to a predetermined setting parameter, so as to ensure a conducting voltage of the illuminating unit to vary according to a variation in the inputted power supply. | 03-28-2013 |
20130082601 | OVER-VOLTAGE HANDLING OF LIGHTING DEVICE - The present disclosure relates to a lighting device that employs at least one string of LEDs as a lighting source. The string of LEDs is coupled in series with a first semiconductor switch, wherein the string of LEDs and the first semiconductor switch are coupled between a power supply node and ground. During a period when the lighting device is powering up after being initially provided power by a power supply, the system controller is configured to monitor a drive current through the first string of LEDs and modulate a control signal provided to the first semiconductor switch based on the drive current to prevent the drive current from exceeding a maximum allowable drive current value for the first string of LEDs. | 04-04-2013 |
20130082602 | OVERCURRENT HANDLING FOR A LIGHTING DEVICE - The present disclosure relates to a lighting device that employs at least one string of LEDs as a lighting source. The string of LEDs is coupled in series with a first switch, wherein the string of LEDs and the first switch are coupled between a power supply node and ground. During a normal operation mode, a system controller is configured to operate the first switch to deliver a drive current to the string of LEDs from the power supply node. The system controller is associated with circuitry that allows the system controller to monitor the drive current and determine when an overcurrent condition occurs. Upon detecting the overcurrent condition, the system controller will open the first switch to stop the drive current from flowing through the string of LEDs. | 04-04-2013 |
20130082603 | LED Device with Simultaneous Open and Short Detection Function and Method Thereof - An LED device with simultaneous open and short detection function includes a plurality of LED strings, a voltage converter, a current driving unit, a loop control unit and an open and short detector. The open and short detector is utilized for performing LED open and LED short detection on the plurality of LED strings according to negative electrode voltages of the plurality of LED strings and a level variation trend of a second voltage converted from a first voltage by the voltage converter. | 04-04-2013 |
20130093327 | CONTROL METHODS FOR LED CHAINS - Control methods for driving LED chains. An output power is provided to drive the LED chains. Short protections are provided to the LED chains, respectively. Whether at least one of the LED chains encounters an under-current event is detected. If any one of the LED chains encounters the under-current event, all short protections are stopped. Whether the output power reaches safe requirement is detected. After the output power reaches the safe requirement, the short protection corresponding to a normal LED chain is resumed. The normal LED chain refers to one of the LED chains that does not encounter the under-current event. | 04-18-2013 |
20130099671 | POWER SUPPLY DEVICE AND DRIVING DEVICE - A power supply device includes a driving device. The power supply device supplies DC power to a light source unit having multiple light sources. The driving device determines whether a current flowing in the light source unit is outside a pre-set current range. When the current flowing in the light source unit is outside the pre-set current range, the driving device changes the number of light sources driven in the light source unit. | 04-25-2013 |
20130106291 | LIGHTING DEVICE FOR AN AC POWER SUPPLY | 05-02-2013 |
20130106292 | LED PROTECTION CIRCUIT | 05-02-2013 |
20130113381 | Color Correcting Device Driver - A color correcting device driver is configured to vary the equivalent current into light emitting elements (e.g., LEDs) with the frequency of the AC input current (e.g., 120 Hz). In implementations that include a fly-back controller with a power factor correction (PFC) controller on the primary side, the color correcting device driver performs the method of: 1) turning on the loads (e.g., white and CA strings of LEDs); 2) determining if the voltage supplied to the loads has dropped by a first threshold amount; 3) turning off the loads; and 4) determining if the voltage supplied to loads has recovered by a second threshold amount (or waiting for a fixed amount of time). The method is repeated. In implementations that do not include a PFC controller on the primary side, the color correcting device driver can create a pulse width modulated (PWM) signal. | 05-09-2013 |
20130119868 | OPTIMAL POWER SUPPLY TOPOLOGIES FOR SWITCHED CURRENT-DRIVEN LEDS - Optimal power supply topologies that do not use output bulk capacitors as well as freewheeling diodes in output section to therefore provide efficiency, cost, volume, and weight advantage over the existing solutions. The present invention applies a pulse-width modulated switched current at higher frequency (in order of 10 to 100 kHz) to LEDs without degrading optical performance. LEDs' average current control is attained using a feedback loop that senses the average value of LEDs' current and controls the current by varying the pulse width of applied current. | 05-16-2013 |
20130127344 | Adaptive Switch Mode LED Driver - An adaptive switch mode LED driver provides an intelligent approach to driving multiple strings of LEDs. The LED driver determines an optimal current level for each LED channel from a limited set of allowed currents. The LDO driver then determines a PWM duty cycle for driving the LEDs in each LED channel to provide precise brightness control over the LED channels. Beneficially, the LED driver minimizes the power dissipation in the LDO circuits driving each LED string, while also ensuring that the currents in each LED string are maintained within a limited range. A sample and hold LDO allows PWM control over extreme duty cycles with very fast dynamic response. Furthermore, fault protection circuitry ensures fault-free startup and operation of the LED driver. | 05-23-2013 |
20130134883 | INTELLIGENT POWER CONTROL SYSTEM - An intelligent power control system connects with a LED power adaptor and a LED light string and drives the LED light string to emit light. The intelligent power control system comprises a sensing-modulating-setting (SMS) unit and a digital power control unit. The SMS unit detects an infrared signal and generates a plurality of brightness-selection signals. The digital power control unit connects with the SMS unit and regulates the output power thereof according to the infrared signal and the brightness-selection signal of the SMS unit to modulate the brightness of the light emitted by the LED light string. The intelligent power control system can stepwise modulate the brightness of the LED light string to reduce power consumption without using any expensive sensor. | 05-30-2013 |
20130134884 | ORGANIC EL ELEMENT LIGHTING DEVICE AND LIGHTING FIXTURE USING THE SAME - An object of the present invention is to provide an organic EL element lighting device whereby surge current can be reduced at start-up while controlling start-up variation, along with a lighting fixture using the same. Provided are a current supply part for supplying lighting current to a light source formed of one or more organic EL elements and connected between output terminals of the current supply part, a current detection part for detecting the lighting current, a target setting part for setting a target value of the lighting current, and a control part for performing feedback control of the lighting current by controlling the current supply part so that the detected value of the current detection part matches the target value of the lighting current. The target setting part has a sweep period during which the target value is gradually increased at start-up of the light source. | 05-30-2013 |
20130147358 | Self-Power for Device Driver - The disclosed implementations utilize the voltage drop inherent in the device string to power a device control IC. In some implementations, current is drawn from the bottom of the device string and applied to a voltage supply pin of the device control IC. In some implementations, current is drawn from some other location in the device string (e.g., near the bottom or midpoint of the device string) using a switch. In some implementations, current is drawn from near the bottom and the bottom of the device string at different times, such that less current is drawn from the bottom of the device string as the duty cycle of the device string increases and more current is drawn from near the bottom of the device string as the duty cycle of the device string increases. | 06-13-2013 |
20130147359 | Lighting Devices Including Current Shunting Responsive To LED Nodes And Related Methods - A solid state lighting device may include a power supply and a light emitting device electrically coupled between the power supply and a reference node, with the light emitting device defining a node. A control element may be provided in a current shunting path electrically coupled in parallel with the light emitting device between the power supply and the reference node, with the control element being configured to control a voltage drop across the current shunting path responsive to an electrical signal from the node of the light emitting device. Related methods are also discussed. | 06-13-2013 |
20130147360 | LED DRIVER APPARATUS - A light-emitting diode (LED) driver apparatus is provided. The LED driver apparatus includes a pulse width modulation (PWM) signal generating unit, a DC-DC converter, and a comparison voltage generating unit. The PWM signal generating unit generates a PWM signal according to a comparison voltage. The DC-DC converter supplies a driving voltage of an LED array by using the PWM signal. The comparison voltage generating unit measures a feedback voltage of the LED array and supplies a difference between the measured feedback voltage and a target voltage as a comparison voltage to the PWM signal generating unit. The comparison voltage generating unit supplies a second reference voltage as a comparison voltage to the PWM signal generating unit from a time when the driving voltage is higher than or equal to a first reference voltage to a time when the driving voltage reaches the target voltage. | 06-13-2013 |
20130147361 | DETECTING CIRCUIT FOR SHORT OF LED ARRAY AND LED DRIVING APPARATUS USING THE SAME - A detection circuit configured to detect a short in a plurality of LED arrays is provided. The detection circuit includes a voltage measuring unit, a short detecting unit, and a detection control unit. The voltage measuring unit is configured to measure respective feedback voltages of the plurality of LED arrays and output a lowest measured feedback voltage as a first feedback voltage. The short detecting unit is configured to detect the short in the LED arrays using the measured feedback voltages. The detection control unit is configured to control the short detecting unit to stop short detection operation, when the first feedback voltage exceeds a first preset reference voltage. | 06-13-2013 |
20130147362 | SHORT CIRCUIT DETECTION CIRCUIT AND CONTROL METHOD THEREOF - A short circuit detection circuit for detecting short circuit of a series of light-emitting diodes includes a constant current source, a rectifier, and a detector. The constant circuit source provides a setting current. The rectifier is coupled between a feedback node and the constant current source. The feedback node is coupled to a terminal of the series of light-emitting diodes. When a feedback voltage of the feedback node exceeds a short reference voltage, the rectifier allows the setting current sinks the feedback node. The detector detects the feedback voltage of the feedback node. When the feedback voltage exceeds a predetermined value, short-circuit protection is triggered to make the series of light-emitting diodes be turned off. | 06-13-2013 |
20130154483 | METHOD AND APPARATUS TO MEASURE LIGHT INTENSITY - A method for controlling a light emitting diode (LED) is provided. Initially, the LED, which had been active, is deactivated, and a voltage for a current that corresponds to the persistence of the LED is generated. The voltage is then integrated so as to generate an integrated voltage, and the integrated voltage is compared to a threshold. When the integrated voltage is less than the threshold, the LED is then activated. | 06-20-2013 |
20130154484 | LED Driving System for Driving Multi-String LEDS and the Method Thereof - A LED driving system comprising: an input port to receive an input signal; a switch node to provide a switching signal; an energy storage component coupled between the input port and the switch node; a main switch coupled between the switch node and ground; n output lines coupled in parallel, and each output line having a first and second terminals, and wherein the first terminal is coupled to the switch node, and the second terminal is coupled the reference ground, and wherein each output line having an output switch, a diode and a LED string coupled in series between the first and second terminals, and wherein each output line having a capacitor coupled in parallel with the LED string; and a controller providing a control signal to the main switch and providing corresponding n control signals to the corresponding n output switches in the corresponding n output lines. | 06-20-2013 |
20130162144 | LIGHT EMITTING DIODE DRIVING APPARATUS - Provided is an LED driving apparatus. The LED driving apparatus includes a plurality of LED groups each comprising one or more diodes, a switch group comprising a plurality of switch units connected respectively to the LED groups to drive the connected LED group when a control signal is activated, and a switch controlling unit configured to compare an input voltage of the LED groups with an output voltage of the LED groups, calculate a comparison value, and generate the control signal according to the comparison value. Accordingly, the LED driving apparatus drives the LED groups selectively according to the difference between the input voltage of the LED group and the output voltage of the LED group, thereby overcoming the problem of heat generation by forward voltage distribution. | 06-27-2013 |
20130169159 | Solid-State Lighting Apparatus and Methods Using Parallel-Connected Segment Bypass Circuits - A lighting apparatus includes a plurality of light emitting diode (LED) sets coupled in series. The apparatus further includes a bypass circuit coupled in parallel with one of the LED sets and configured to sense and control a bypass current when the one of the LED sets is in a first bias state and to attenuate the bypass current responsive to a transition of the one of the LED sets to a second bias state. The first bias state may be substantially non-conducting and the second bias state may be conducting. The apparatus may include a plurality of such bypass circuits, respective ones of which are coupled in parallel with respective ones of the LED sets such that the bypass circuits are coupled in series. | 07-04-2013 |
20130169160 | LED DRIVER CIRCUIT AND LIGHT APPARATUS HAVING THE SAME IN - A light-emitting diode (LED) driver circuit and a light apparatus including the LED driver circuit are provided. The light apparatus includes an LED array, an input unit, a rectifier, and a control circuit. The LED array includes LED devices connected to one another in series. The input unit receives an alternating current (AC) power source. The rectifier circuit full-wave rectifies the received AC power source signal and supplies the full-wave rectified AC power source signal to the LED array. The control circuit selectively lights the LED devices according to a voltage level of the full-wave rectified AC power source signal. The control circuit includes switching elements and comparators. The switching elements selectively force nodes between the LED devices to be grounded. The comparators turn-on one of the switching elements according to the voltage level of the full-wave rectified AC power source signal. | 07-04-2013 |
20130175929 | METHOD AND CIRCUIT ARRANGEMENT FOR REGULATING A LED CURRENT FLOWING THROUGH A LED CIRCUIT ARRANGEMENT, AND ASSOCIATED CIRCUIT COMPOSITION AND LIGHTING SYSTEM - Consistent with an example embodiment there is 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. | 07-11-2013 |
20130187550 | LED LIGHTING CIRCUIT CAPABLE OF PREVENTING THERMAL BREAKDOWN - An LED lighting circuit capable of preventing thermal breakdown, including: an LED module, having a top end coupled to a line voltage; and a controller, coupled to the line voltage and a bottom end of the LED module, the controller including: an amplifier, having a positive input end coupled to an adjustable reference voltage; a transistor, having a gate terminal coupled to an output end of the amplifier, a first channel terminal coupled to the bottom end of the LED module, and a second channel terminal coupled to a negative input end of the amplifier; a current sensing resistor, coupled between the second channel terminal and a ground; and a reference voltage generator, used for generating the adjustable reference voltage according to the line voltage. | 07-25-2013 |
20130187551 | Method and System for Driving LEDs from a Source of Rectified AC Voltage - The present inventions relate to a control circuit for controlling a plurality of serially connected groups of LEDs. A control unit is connected in parallel to each group of a plurality of serially connected groups of LEDs. Each LED group is connected to the adjacent group of LEDs. The control unit is connected to a group of LEDs. The control unit performs the functions of voltage regulating/current regulating/bypass for the associated group of LEDs. The control unit can act as a by-pass unit permitting current to flow through the control unit rather than through the associated group of LEDs. | 07-25-2013 |
20130193852 | LED MATRIX MANAGER - Circuits for controlling a plurality of LEDs connected in series are disclosed herein. The circuit includes a plurality of switches, wherein each switch is connectable between the anode and cathode of one of the plurality of LEDs. Each of the switches has a first state wherein current does not pass through the switch and a second state wherein current passes through the switch. The circuit also includes an input for receiving data to program the switches and a data line for transferring data between a circuit controlling second LEDs that are connected in parallel with the first LEDs and the circuit. In addition, the circuit includes a data output for transferring data to other circuits controlling third LEDs that are connected in series with the first LEDs. | 08-01-2013 |
20130200801 | BYPASS CIRCUIT FOR SERIES CONNECTED LEDs USED FOR BACKLIGHTING - Disclosed are various embodiments of bypass circuits that can be used with series connected LED strings for backlighting circuits in LCD displays. The bypass circuits can also be used for other implementations of series wired LED strings. The bypass circuit may comprise a latch, such as a silicon controlled rectifier that is connected to the output of a comparator circuit that compares the voltage at the cathode of an LED in the LED string to a reference voltage. In this manner, a circuit is created around each LED that is burned out. | 08-08-2013 |
20130200802 | LIGHT-EMITTING DIODE DRIVING APPARATUS - An apparatus includes first and fourth bypasses, a current detector, and a current controller. The first bypass is connected serially to a first LED, and controls the current amount in the first LED. The fourth bypass is connected serially to a second LED, and controls the current amount in the first and second LEDs. The detector detects current detection signal based on the current amount on an output line along which the first and second LEDs are connected serially to each other. The controller provides control signal for controlling the first and fourth bypasses based on the detection signal. The controller includes one output for providing the control signal. The first and fourth bypasses are connected in parallel to the one output. | 08-08-2013 |
20130234600 | LED FLUORESCENT LAMP - A light-emitting diode (LED) fluorescent lamp which can replace a typical fluorescent lamp is provided. The LED fluorescent lamp includes an LED array including a plurality of LEDs connected in series; first through fourth connection pins; first through fourth capacitors connected to the first through fourth connection pins, respectively; a first diode having an commonly connected to second ends of the first and third capacitors and a cathode connected to a first end of the LED array; a second diode having an anode connected to a second end of the LED array and a cathode commonly connected to second ends of the second and fourth capacitors. The LED fluorescent lamp can replace a typical fluorescent lamp without a requirement of the installation of additional equipment or the change of wiring. | 09-12-2013 |
20130249406 | LED Emitting Device and Driving Method Thereof - Disclosed are an LED emitting device and driving method thereof. The LED emitting device controls an LED drive switch connected to a first end of an LED string to control an output current supplied to the LED string. The LED emitting device generates feedback information on the output voltage or the output current supplied to the LED string, and uses the output current to sense an open lamp state of the LED string. The LED emitting device uses a voltage at a first end of the LED drive switch to sense a change of the LED string to a normal state from the open lamp state. | 09-26-2013 |
20130257280 | Delaying Startup Under Fault Conditions - A LED lamp that includes a LED lamp controller with delayed startup after a fault condition is detected. The type of the fault condition is used in determining a length of the startup delay, such as a number of power cycles during which the LED lamp controller is prevented from completing its configuration. Examples of different types of fault conditions include faults in a supply voltage or faults in a feedback voltage to the LED lamp controller. Fault type information can also be stored in circuitry that retains data and is not reset across the power cycles. | 10-03-2013 |
20130257281 | Marker Lamp and Marker Lamp System - According to one embodiment, a marker lamp is supplied with electric power from an alternating constant-current power supply device via a saturable device. The marker lamp includes a solid-state light-emitting circuit functioning as a light source and a lighting circuit configured to subject the solid-state light-emitting circuit to lighting control. The marker lamp further includes an abnormality monitoring device configured to monitor a state of the solid-state light-emitting circuit and open, if detecting an abnormal state, an output side of the saturable device corresponding to the marker lamp. | 10-03-2013 |
20130257282 | LED DRIVER AND A METHOD OF DRIVING LEDS - A method of driving current from an AC power supply through a series arrangement of a varying number of strings of LEDs is disclosed, the method comprising, adding LED strings to the series arrangement in a first order during an increasing voltage part of a cycle of the AC power supply cycle and subsequently removing LED strings from the series arrangement in a second order s during a decreasing voltage part of the cycle, wherein the second order is not the reverse of the first order. A driver for operating such a method is also disclosed, as is an IC embodying such a driver. | 10-03-2013 |
20130271008 | Light-emitting Diode (LED) Driving Circuit - A light-emitting diode (LED) driving circuit for driving a plurality of first lightbars and a plurality of second lightbars is provided. The LED driving circuit includes a first current mirror, a second current mirror and a control circuit. The first current mirror, if enabled, balances currents of the first lightbars. The second current mirror, if enabled, balances currents of the second lightbars. During a first period, the control circuit disables the second current mirror and adjusts the duration of enabling the first current mirror according to a dimming signal. During a second period, the control circuit disables the first current mirror and adjusts the duration of enabling the second current mirror according to the dimming signal. Therefore, only the first lightbars or the second lightbars are driven in each period. | 10-17-2013 |
20130278145 | CIRCUITS AND METHODS FOR DRIVING LIGHT SOURCES - A dimming controller can operate in a first mode or a second mode to control dimming of a light source. A voltage control terminal provides a driving signal to control a control switch. When the dimming controller operates in the first mode, the driving signal controls the control switch in a first state and a second state alternately to adjust a first current flowing through the first light element to a target level. When the dimming controller operates in the second mode, the driving signal controls the control switch in the second state to cut off the first current. A high voltage terminal conducts a current flowing through the control circuit and the second light element when the dimming controller operates in the second mode. The control circuit conducts a second current flowing through the second light element during the second mode. | 10-24-2013 |
20130293108 | CONSTANT CURRENT PULSE-WIDTH MODULATION LIGHTING SYSTEM AND ASSOCIATED METHODS - A lighting system comprising a constant current power source one or more sets of light emitting elements, and associated circuitry. The light emitting elements may be light emitting diodes (LEDs) that have been selected to emit light having specific wavelengths corresponding to specific colors. The lighting system may selectively control the intensity of each set of LED by utilizing pulse-width modulation. The sets of LEDs may be serially connected and selectively operated independently of each other set of LEDs. | 11-07-2013 |
20130293109 | LED DRIVER IC, DRIVING METHOD THEREOF, AND LED EMITTING DEVICE USING THE LED DRIVER IC AND THE DRIVING METHOD - The present invention relates to an LED driver IC, a driving method of the LED driver IC, and an LED light emission device using the LED driver IC. The LED light emission device includes an LED string, a power switch supplying power to the LED string, a dimming switch controlling light emission duty of the LED string, and an LED driver IC controlling switching operation of the power switch and the dimming switch. The LED driver IC senses a difference between a control electrode voltage of the dimming switch and a sense voltage generated according to a current flowing to the dimming switch, and triggers the OCP operation according to a result of comparison between the sensed voltage and a predetermined OCP reference voltage. | 11-07-2013 |
20130300293 | Active LED Voltage Clamp - An active clamp current sink is used to voltage protect a low voltage rated, high power current sink that drives illumination current through a string of serially connected LEDs. When the LEDs are turned off as part of a PWM configuration, the forward voltage on the LEDs falls, and the voltage presented to the low voltage rated, high power current sink rises. The active clamp current sink monitors the voltage across the high power current sink and ensures that an adequate current flows through the LEDs. This minimally adequate current maintains a sufficiently large forward voltage through the LEDs, and therefore a sufficiently small voltage is presented to the high power current sink. | 11-14-2013 |
20130300294 | METHOD AND SYSTEM FOR DRIVING LIGHT EMITTING ELEMENTS - A system topology and circuit design for efficiently and stably driving currents through strings of solid state light emitting elements by providing current sources that are controlled by a stable voltage reference. | 11-14-2013 |
20130300295 | APPARATUS AND METHOD FOR BYPASSING FAILED LEDS IN LIGHTING ARRAYS - An apparatus, method and system for controlling one or multiple lighting sources such as those powered by driver circuits or voltage splitting methods, to provide an alternative current path around a failed lighting source when one or more individual lighting sources fail. | 11-14-2013 |
20130307415 | SOLID-STATE LIGHTING APPARATUS AND METHODS USING SWITCHED ENERGY STORAGE - An apparatus includes at least one LED, at least one charge storage device and a switching circuit configured to route current through the least one LED to the at least one charge storage device for a first state of an applied voltage and to discharge the at least one charge storage device via the at least one LED for a second state of the applied voltage. The apparatus may further include a current control circuit coupled in series with the at least one LED. | 11-21-2013 |
20130307416 | OPEN CIRCUIT PROTECTING CIRCUIT, OPEN CIRCUIT PROTECTING METHOD AND ILLUMINATING APPARATUS - The present application discloses an open circuit protecting circuit, an open circuit protecting method and an illuminating apparatus. The open circuit protecting circuit is configured in an apparatus with a LED load being supplied with power by a current source, and comprises: a switch circuit, a timer circuit and a detecting circuit. When the LED load malfunctions, the open circuit protecting circuit carries out the following operations: the detecting circuit sends an enabling signal to the timer circuit, the timer circuit sends a driving signal with a set time to the switch circuit and the switch circuit is in the on-state during the set time, so as to make the LED load be short circuited to protect the circuit from being damaged. The open circuit protecting circuit can also resume to normal work automatically after the open circuited malfunction is cleared, and thus a hot-plugging function can be realized. | 11-21-2013 |
20130313972 | MULTICOLOR LED SEQUENCER - A multicolored LED luminaire module is provided that can be controlled using a single driver and only two wires. The LED luminaire module comprises a plurality of LEDs and a sequencer. The sequencer connects each LED to the circuit in a predetermined order. Synchronously with the sequencer, the driver transmits a control signal comprising a time division multiplexed (TDM) signal that combines the driving currents for each LED into one TDM signal. The sequencer and TDM rate are sufficiently fast such that the light emitted by the LED luminaire appears to be the combined light from all the LEDs. | 11-28-2013 |
20130313973 | LED BYPASS AND CONTROL CIRCUIT FOR FAULT TOLERANT LED SYSTEMS - A light system (FIG. | 11-28-2013 |
20130320857 | LIGHT EMITTING DIODE DRIVING CIRCUIT - The present disclosure provides a light emitting diode driving circuit, comprising: a power conversion module having an input end, a control end and an output end, wherein the input end receives a voltage, the control end controls the regulation of the duty cycle signal therein according to a received control signal, and the output end outputs a DC voltage having a constant current and a variable voltage value; an overcurrent protection circuit having a switch module and a first resistor connected in series, wherein the overcurrent protection circuit and a LED load connected in series with each other are connected to the power conversion module, so as to turn off the electrical channel between the LED load and the power conversion module when overcurrent occurs; and an overvoltage protection circuit for outputting the control signal when overvoltage occurs and thereby protecting the LED load. | 12-05-2013 |
20130334968 | Power Supply for LED Illumination - An LED illumination system includes: a load including an LED lamp; and a power supply device, the LED lamp configured to be physically mounted on and demounted from the power supply device, the power supply device comprising: a current feedback control unit; a first voltage comparison unit configured to determine whether the load is in a mounted state; a voltage feedback control unit configured to decrease the voltage of the power supply device to a safe voltage when demounting, and to increase the voltage of the power supply device to perform the constant current control when mounting; and a semiconductor switch element connected in series between the load and the detection resistor, wherein the mounted and demounted states of the load is detected by a voltage of a main electrode of a high potential side of the semiconductor switch element. | 12-19-2013 |
20140001958 | CIRCUIT, DEVICE AND METHOD OF DIRECTLY DRIVING LED | 01-02-2014 |
20140015414 | SOLID STATE LIGHTING CIRCUIT AND CONTROLS - In some embodiments, a solid state lighting circuit may include one or more of the following features: (a) a plurality of emitters operably connected to a power supply (b) the power supply operably coupled in series with a current limiting device, where one or more of the emitters is bypassed with a switched circuit, and (c) at least one MOSFET switch operably coupled to the voltage divider circuit. | 01-16-2014 |
20140042907 | LED DRIVING DEVICE - A LED driving device adapted to driving N LED strings connected in series is provided. N is a positive integer greater than 1. The LED driving device includes (N−1) switch units, a current source, a detection unit and a control unit. The ith switch unit electrically connects to the (i+1) LED string in parallel or to the ith LED string in parallel, and 0 | 02-13-2014 |
20140084793 | LED FLOURESCENT LAMP - An LED fluorescent lamp includes: an LED array having a plurality of LEDs connected in series; a first connection pin and a third connection pin connected to one side of the LED array; a second connection pin and a fourth connection pin connected to the other side of the LED array; at least one pair of capacitors connected to the LED array; and a short-circuit means for connecting at least one of the first connection pin and the third connection pin, and the second connection pin and the fourth connection pin, wherein the capacitors include: a first capacitor having one end connected to the first connection pin and the other end connected to one side of the LED array; a third capacitor having one end connected to the third connection pin and the other end connected to the one side of the LED array; a second capacitor having one end connected to the second connection pin and the other end connected to the other side of the LED array; and a fourth capacitor having one end connected to the fourth connection pin and the other end connected to the other side of the LED array. The LED fluorescent lamp can use an instant start electronic ballast that is a fluorescent lamp ballast installed in an existing lamp with no change. | 03-27-2014 |
20140091714 | CURRENT LIMITING CIRCUIT AND METHOD FOR LED DRIVER - Aspects of the disclosure provide a circuit that includes a driver circuit and a current limiter circuit. The driver circuit is configured to drive a load with an output current when the load is coupled with the driver circuit. The current limiter circuit is configured to turn on a path to deplete a portion of the output current from the driver circuit in order to prevent a load current flowing through the load from exceeding a current limit. | 04-03-2014 |
20140097754 | LIGHT EMITTING DIODE LUMINANCE SYSTEM HAVING CLAMPING DEVICE - A light emitting diode luminance system includes a first power source, a voltage divider, a first switch, a clamping device, a plurality of current sources and a feedback circuit. The voltage divider is coupled to the first voltage source. The first switch is coupled to the voltage divider and a ground. The clamping device includes a plurality of transistors each coupled to a respective set of light emitting diodes and the voltage divider. The plurality of current sources is coupled to the plurality of transistors respectively. The feedback circuit is coupled to the plurality of transistors and the plurality sets of light emitting diodes. | 04-10-2014 |
20140097755 | Drivers and Driving Methods for a LED String, Capable of Providing LED Short Protection or Avoiding LED Flickering - The disclosure regards to drivers and driving methods for a LED string consisting of LEDs. The LED string and a current switch are coupled in series between a power line and a ground line. The power line is powered to regulate a signal representing a current passing through the LED string. An enable signal capable of switching the current switch is provided. Whether a predetermined event occurs is detected. When the predetermined event occurs, the enable signal is clamped to have a predetermined logic value, the current switch thereby being kept either open or short. | 04-10-2014 |
20140111090 | TEMPERATURE FOLDBACK CIRCUIT FOR LED LOAD CONTROL BY CONSTANT CURRENT SOURCE - An apparatus includes an input node, a light-emitting diode (LED) string to receive a current from the input node, a voltage divider to output a control voltage, and a switch to receive the control voltage. The switch coupled to the LED string controls the current through the LED string according to the control voltage. | 04-24-2014 |
20140111091 | SPECTRAL SHIFT CONTROL FOR DIMMABLE AC LED LIGHTING - Apparatus and associated methods involve operation of an LED light engine in which a relative intensities of selected wavelengths shift as a function of electrical excitation. In an illustrative example, current may be selectively and automatically diverted substantially away from at least one of a number of LEDs arranged in a series circuit until the current or its associated periodic excitation voltage reaches a predetermined threshold level. The diversion current may be smoothly reduced in transition as the excitation current or voltage rises substantially above the predetermined threshold level. A color temperature of the light output may be substantially changed as a predetermined function of the excitation voltage. For example, some embodiments may substantially increase or decrease a color temperature output by a solid state light engine in response to dimming the AC voltage excitation (e.g., by phase-cutting or amplitude modulation). | 04-24-2014 |
20140117854 | LED LIGHTING DRIVER - A light-emitting diode (LED) lighting driver is provided, which includes a bridge rectifier, multiple LED sections, multiple shunt regulators, a weighted current mirror array, a mean power integrator, and a reference generator. The bridge rectifier provides a rectified sinusoidal voltage. The LED sections are coupled in series and coupled to the rectified sinusoidal voltage. Each shunt regulators regulates a shunt current flowing out from the LED sections according to a current reference value. The weighted current mirror array provides a plurality of copy currents. Each copy currents tracks the conduction time of one shunt regulator and also tracks the instantaneous output power of the LED sections. The mean power integrator provides a mean power value by integrating the copy currents. The reference generator provides the current reference values. Each current reference values is directly proportional to the difference between a mean power reference value and the mean power value. | 05-01-2014 |
20140125229 | MULTI-SEGMENT LED LIGHTING APPARATUS CONFIGURATIONS - A solid state lighting apparatus can include a Light Emitting Diode (LED) string that includes a plurality of light emitting diode (LED) segments that are coupled in series with one another wherein a ratio of respective numbers of LEDs in each of the segments is about equal to a ratio of respective average powers for each of the respective segments. Other configurations are also disclosed. | 05-08-2014 |
20140125230 | APPARATUS, METHOD AND SYSTEM FOR PROVIDING AC LINE POWER TO LIGHTING DEVICES - An apparatus, method and system are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). A representative apparatus comprises: a plurality of LEDs coupled in series to form a plurality of segments of LEDs; first and second current regulators; a current sensor; and a controller to monitor a current level through a series LED current path, and to provide for first or second segments of LEDs to be in or out of the series LED current path at different current levels. A voltage regulator is also utilized to provide a voltage during a zero-crossing interval of the AC voltage. In a representative embodiment, first and second segments of LEDs are both in the series LED current path regulated at a lower current level compared to when only the first segment of LEDs is in the series LED current path. | 05-08-2014 |
20140139110 | LED BACKLIGHT DRIVING CIRCUIT, BACKLIGHT MODULE, AND LCD DEVICE - A light emitting diode (LED) backlight driving circuit includes an LED lightbar, and a constant current chip that controls current flowing through the LED lightbar. The LED backlight driving circuit further includes a comparison module that receives an output voltage of the LED lightbar. When the output voltage of the LED lightbar is greater than the preset reference voltage, the comparison module controls the constant current chip to switch off the current of the LED lightbar. | 05-22-2014 |
20140139111 | LOAD DRIVING APPARATUS RELATED TO LIGHT EMITTING DIODES - A load driving apparatus related to light emitting diodes (LED) is provided. The load driving apparatus includes a power conversion circuit, a complex function circuit, and a control chip. The power conversion circuit receives a DC input voltage and provides a DC output voltage to at least one LED string in response to a gate pulse-width-modulation (PWM) signal. The complex function circuit is serially connected with the LED string and provides a short-protection mechanism. The control chip is coupled to the power conversion circuit and the complex function circuit. The control chip generates the gate PWM signal to control the operation of the power conversion circuit, and when the LED string is short-circuited, the control chip controls the complex function circuit to activate the short-protection mechanism, so as to protect the load driving apparatus from being damaged. | 05-22-2014 |
20140139112 | APPARATUS AND METHOD FOR PROVIDING AC LINE POWER TO LIGHTING DEVICES - Apparatus and method are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). A representative apparatus comprises: a plurality of LEDs couplable to form a plurality of segments of LEDs; a current sensor; and a controller to monitor a current level through an overall series LED current path, and to provide for first or second segments of LEDs to be in or out of the overall series LED current path at different current levels. The controller is configured to, in a first light emitting diode configuration, cause first and second segments of LEDs to be parallel to one another and in the overall series LED current path. The controller is further configured to, in a second light emitting diode configuration, cause first and second segments of light emitting diodes to be coupled in series and in the overall series light emitting diode current path. | 05-22-2014 |
20140152180 | Short Circuit Detection for Lighting Circuits - This invention relates to control circuits for LED systems with a feedback loop to regulate a drive voltage. A controller for the system is proposed comprising a plurality of LED circuits and a controllable power source. The controller comprises a control unit configured to cause regulation of the drive voltage based on a determination of a plurality of feedback voltages and a fault condition detecting means. At least one of the LED circuits is determined as having a fault condition if the respective feedback voltage is below a fault threshold. In response to a detected fault condition, a test voltage is applied to a cathode of the fault circuit to confirm the presence of a fault condition. | 06-05-2014 |
20140152181 | Music Synchronized Light Modulator - The subject matter disclosed herein relates to a system for controlling strings of lights. This system can include a host controller, one or more strings of lights, and an effects modulator. Each string of light can include at least one LED light. The effects modulator can be operatively connected to the host controller and to the strings of light. The effects modulator can include a microcontroller and an inverter. The inverter can include a high side driver circuit and one or more low side driver circuits operatively connected to the high side driver circuit. Each low side driver circuit can be operatively connected to one of the strings of light. The microcontroller can be configured to receive one or more control signals from the host controller and control the strings of light via the inverter in accordance with the control signals. Related apparatus, methods, and techniques are also described. | 06-05-2014 |
20140152182 | LIGHTING DEVICE AND LUMINAIRE INCLUDING THE SAME - A lighting device ( | 06-05-2014 |
20140159584 | SPECTRAL SHIFT CONTROL AND METHODS FOR DIMMABLE AC LED LIGHTING - Apparatus and associated methods involve operation of an LED light engine in which a relative intensities of selected wavelengths shift as a function of electrical excitation. In an illustrative example, current may be selectively and automatically diverted substantially away from at least one of a number of LEDs arranged in a series circuit until the current or its associated periodic excitation voltage reaches a predetermined threshold level. The diversion current may be smoothly reduced in transition as the excitation current or voltage rises substantially above the predetermined threshold level. A color temperature of the light output may be substantially changed as a predetermined function of the excitation voltage. For example, some embodiments may substantially increase or decrease a color temperature output by a solid state light engine in response to dimming the AC voltage excitation (e.g., by phase-cutting or amplitude modulation). | 06-12-2014 |
20140175983 | LED lamp - A lamp is provided with a full-wave rectifier for convert AC to DC; a SPD electrically connected to the full-wave rectifier for protecting the lamp from voltage spikes; series connected LEDs electrically connected to the SPD; a microprocessor electrically connected to the SPD; series connected MOSFET start circuits electrically to the microprocessor, the MOSFET start circuits configured to switch electronic signals; and resistors each electrically interconnected the LED and the MOSFET start circuit. In response to a normal DC supplied from the SPD, the microprocessor creates a PWM signal to activate the MOSFET start circuits which in turn initiate operations of the LEDs via the resistors respectively. In response to an abnormal DC having voltage spikes supplied from the SPD, the microprocessor deactivates the MOSFET start circuits which in turn direct the DC through the resistors rather than supply the DC to the LEDs via the resistors respectively. | 06-26-2014 |
20140184077 | LIGHT EMITTING DIODE DRIVING APPARATUS - There is provided a light emitting diode (LED) driving apparatus configured such that a waveform of current input to an LED follows a sine wave, the LED driving apparatus including, a switching unit switching an LED unit having a plurality of LEDs receiving rectified power and emitting light, a driving control unit controlling the switching of the switching unit according to a voltage level of the rectified power, a current limiting unit limiting current flowing in the LED unit, and an adjusting unit adjusting current limitation of the current limiting unit according to the voltage level of the rectified power. | 07-03-2014 |
20140184078 | LIGHT EMITTING DIODE DRIVING DEVICE - There is provided a light emitting diode driving device capable of preventing a number of switches from being turned on simultaneously when a plurality of light emitting diodes are respectively driven using a plurality of switches, the light emitting diode driving device, including: a light emitting diode unit having a plurality of light emitting diodes connected to one another in series and emitting light through receiving rectified power; and a driving unit having a plurality of drivers driving the plurality of light emitting diodes of the light emitting diode unit, respectively, wherein each of the plurality of drivers selects a maximum voltage from among a plurality of detection voltages with respect to current flowing in at least one light emitting diode corresponding thereto and compares the maximum voltage with a preset reference voltage to thereby drive the corresponding light emitting diode. | 07-03-2014 |
20140184079 | DRIVER CIRCUIT OF LIGHT SOURCES AND VEHICLE LIGHT PROVIDED WITH SAID DRIVER CIRCUIT OF LIGHT SOURCES - Driver circuit of light sources, particularly of the LED type, comprising a first and at least a second group of light sources, each connected to a common power supply terminal, a first and at least a second regulation circuit, each suitable for regulating the current absorbed by a respective group of light sources, at least one actuation circuit operatively connected to a respective second regulation circuit, and a serial connection circuit, suitable for connecting in series at least a first and a second group of light sources, when the voltage downstream of the first group of light sources is greater than or equal to the voltage upstream of the second group of light sources. | 07-03-2014 |
20140184080 | LIGHT EMITTING DIODE LIGHT STRUCTURES - A Light Emitting Diode (LED) light includes a bridge rectifier configured to be powered by an alternating current power source and to produce a rectified output. Control circuitry couples to the bridge rectifier and is configured to produce a shunt signal when the rectified output is less than a threshold voltage. A series connected Light Emitting Diode (LED) string includes a first group of LEDs and a second group of LEDs. A switch couples to a first side of the second group of LEDs and is controlled by the shunt signal to deactivate the second group of LEDs. The control circuitry may include a ratio metric series resistor string configured to sense a proportion of the rectified output and an inverter configured to generate the shunt signal based on the proportion of the rectified output. | 07-03-2014 |
20140184081 | Color Temperature Adjustment for LED Lamps Using Switches - A light-emitting diode (LED) lamp includes a number of different color LEDs that can be turned on and off in different combinations using an external switch operable by a user. A user or a controller can adjust the color temperature of light output by the lamp. The color temperature change may be a user preference and can compensate for decreased phosphor efficiency over time. | 07-03-2014 |
20140197738 | Light Socket for Series LED Lighting - Electrical and mechanical connection for a series connected LED lamp to an appropriate electrical circuit. The circuit contains additional series connected light producing elements. To enable continuous operation of all the other light producing elements in the series circuit, the socket contains a device to bypass the series current to the remaining circuit elements in the case of a defective lamp or connection. Operation of the bypass device is controlled within the socket with operational parameters controlled either from within the socket or in conjunction with an external element in the lamp. The operation of the bypass circuit is latching, once operating the bypass will continue to operate until reset preventing unwanted flicker in the case of intermittent connections. The method of resetting the bypass circuit may be either manual or automatic. The socket bypass may contain a time delay to allow internal bypass circuits included within the lamp to operate before the socket bypass activates. | 07-17-2014 |
20140197739 | DC-DC Converter Protection Circuit and Protection Method Thereof - A protection circuit of a DC-DC converter is disclosed. An input terminal of the DC-DC converter receives an input voltage and an output terminal of the DC-DC converter provides an output voltage. The DC-DC converter includes an output stage between the input terminal and the output terminal The protection circuit includes a current sensor, a comparator, a determining circuit, and a protection control circuit. The current sensor provides a sensing signal. The comparator compares a default over-voltage with the sensing signal to provide an over-current control signal. The determining circuit provides a determining control signal. The protection control circuit determines whether to enable a short protection according to the over-current control signal and the determining control signal. | 07-17-2014 |
20140197740 | LED LIGHT SOURCE - A LED light source comprises a first rectifier (DB | 07-17-2014 |
20140210349 | LIGHT-EMITTING DEVICE AND CONTROL METHOD OF THE SAME - A light-emitting device control method is provided. The light-emitting device control method comprises the steps outlined below. A light-emitting module of a light-emitting device having light-emitting unit string each having light-emitting units connected in series is operated. One end of each light-emitting unit strings receives a same DC voltage. A voltage drop value across each current control units connected in series to at least one of the light-emitting unit strings is retrieved to further determine whether the light-emitting unit of each of the light-emitting unit strings malfunctions. When x light-emitting units of a specific string malfunction and x is larger than or equal to a malfunction threshold value p, the x malfunctioned light-emitting units are shorted and (x−p+1) light-emitting units in each of the light-emitting unit strings other than the specific string are shorted. The DC voltage received by each of the light-emitting units is decreased. | 07-31-2014 |
20140210350 | LOAD DRIVING APPARATUS RELATING TO LIGHT-EMITTING-DIODES - A load driving apparatus relating to light-emitting-diodes (LEDs) is provided. In the invention, a compensation voltage on a compensation pin (CMP) of a control chip would not be changed in response to (or with) the variation (i.e. enabling and disabling) of a pulse-width-modulation (PWM) signal for dimming. In other words, the compensation voltage on the compensation pin (CMP) of the control chip would be maintained in unchanging regardless of whether the PWM signal for dimming is enabled or disabled. Therefore, an LED string at the current switching transient does not have the generation of over-shoot current. | 07-31-2014 |
20140210351 | ELECTRONIC CONTROL GEARS FOR LED LIGHT ENGINE AND APPLICATION THEREOF - Disclosed are electronic control gears for LED light engines able to improve power factor by way of gearing up or down the LED current and the AC input current in response to and in synchronization with the AC input voltage. Moreover, the disclosed electronic control gears could further reduce flicker phenomenon and total harmonic distortion when used in collocation with disclosed valley fillers, filling the LED current valleys only during the dead time, and in conjunction with disclosed dummy loads, ramping up or down the AC input current only during the dead time. | 07-31-2014 |
20140210352 | DRIVING CIRCUITRY FOR LED LIGHTING WITH REDUCED TOTAL HARMONIC DISTORTION - Conditioning circuits are provided for driving two or more LED groups using a rectified AC input voltage. The conditioning circuits uses analog circuitry to gradually and selectively activate the LED groups based on an instantaneous value of the rectified input voltage. The circuit includes a first series interconnection of a first LED group, a first transistor, and a first resistor, and a second series interconnection of a second LED group, a second transistor, and a second resistor. In one example, the second series interconnection is connected between a drain terminal and a source terminal of the first transistor, while in another example, the second series interconnection is connected between an anode of the first LED group and a source terminal of the first transistor. The first and second LED groups are selectively activated by the rectified voltage applied across the first series interconnection. | 07-31-2014 |
20140217899 | LIGHT EMITTING MODULE - A light emitting module includes a plurality of light emitting device packages configured to be sequentially turned on or off according to the level of external drive voltage and connected to one another in series. Each of the plurality of light emitting device packages includes a light emitting cell having at least one light emitting device, and an on/off controller configured to control to turn the light emitting cell on or off. | 08-07-2014 |
20140232270 | LED DRIVING DEVICE AND LED LIGHTING APPARATUS - The present invention supplies desired DC output power to a first LED load and a second LED load whose color temperature is different from that of the first LED load, includes a switching element, ripple current reducers series-connected to the respective LED loads and for reducing current ripples flowing through the LED loads, and a control circuit for controlling the DC output power so that it has a predetermined value, by performing on-off control of the switching element based on a feedback voltage at a connecting point between each of the LED loads and a corresponding one of the ripple current reducers. Each ripple current reducer has feedback-type constant current control circuits for performing control for varying impedance, and the present invention also includes color controllers for performing color control by maintaining a total LED current value of the first and second LED loads at a certain value. | 08-21-2014 |
20140246979 | LED Backlight Drive Circuit - The present invention provides an LED backlight drive circuit, which includes a first power supply module, an electrical inductor, a rectifier diode, a MOS transistor, an electrolytic capacitor, an LED light string, a voltage division module, a voltage comparator, a second power supply module, and an LED constant-current drive chip. The LED backlight drive circuit is arranged to include a voltage comparator in an external circuit of the LED constant-current drive chip to detect output voltage of the drive circuit so that high voltage, the voltage comparator is caused to supply a low voltage level to forcibly pull down a PWM dimming signal or an ENA enabling signal of the LED constant-current drive chip to achieve an over-voltage protection function and also enable removal of over-voltage protection module from a conventional LED constant-current drive chip. | 09-04-2014 |
20140246980 | LED ACTUATION FOR RUNNING LIGHT FLASHERS - A light-emitting diode chain comprising a plurality of light-emitting diodes (LED | 09-04-2014 |
20140292201 | Driver Circuit for Efficiently Driving a Large Number of LEDs - A circuit can be used for controlling a plurality of LEDs coupled in series. A switching converter operates as a current source coupled to the plurality of LEDs to provide a constant load current thereto. The switching converter includes an inductor coupled in series with the plurality of LEDs such that the same load current flows through the inductor and the plurality of LEDs. No substantial capacitance is coupled between the inductor and the plurality of LEDs. A floating driver circuit is coupled in parallel with each individual LED of the plurality of LEDs. The floating driver circuit is configured to fully or partially take over the load current thereby bypassing the respective LED in accordance with a respective modulated input signal to control the intensity of the light emitted by the LED. | 10-02-2014 |
20140320018 | RETROFIT LAMP - A retrofit lamp includes at least one series circuit having a multiplicity of LEDs having a circuit arrangement. The at least one series circuit including is coupled between a first rectifier output connection and a second rectifier output connection. A breakdown apparatus is coupled between a third connection terminal and a fourth connection terminal The breakdown apparatus may have the following properties: up to a first threshold value of the voltage drop across said breakdown apparatus during operation, the breakdown apparatus is nonconducting. If the first threshold value is exceeded, the breakdown apparatus becomes conducting. The breakdown apparatus remains conducting as long as current is supplied to it which is above a second threshold value. As soon as the current falls below the second threshold value, the breakdown apparatus becomes nonconducting again. In the conducting state, the breakdown apparatus has a forward voltage which is below a third threshold value. | 10-30-2014 |
20140327359 | Illumination Apparatus and Light Emitting Module - An illumination apparatus includes: a plurality of light emitting modules connected in series; a constant current source; and a fault detection circuit for detecting that the plurality of light emitting modules have at least one thereof with a short circuit fault. The light emitting module includes: an organic EL panel; a threshold value detection circuit configured to output a constant voltage when the organic EL panel between its anode and cathode has a potential difference equal to or larger than a threshold value; and a VI conversion circuit receiving the constant voltage from the threshold value detection circuit, converting the constant voltage into a constant current, and outputting the constant current. The fault detection circuit detects whether the plurality of light emitting modules have a short circuit fault based on a total value of the constant current output from each light emitting module. | 11-06-2014 |
20140339984 | LED Switch Circuitry for Varying Input Voltage Source - An LED array switching apparatus, comprises: a plurality of LED segments D | 11-20-2014 |
20140346955 | PROTECTION CIRCUIT WITH LOW ENERGY-CONSUMPTION AND DRIVING CIRCUIT THEREOF - The present invention provides a protection circuit with low energy-consumption and driving circuit thereof, including a detection circuit and a switch circuit, with switch circuit disposed between power supply circuit and peripheral step-down shunt; detection circuit and switch circuit connected for controlling. Switch circuit includes a PNP triode or P MOS transistor connected between power supply circuit and peripheral step-down shunt; wherein base of the PNP triode or P MOS transistor connected to drain of another N MOS transistor through resistor, gate of N MOS transistor connected to status pin of detection circuit. The invention solves drawbacks of existent input voltage after circuit entering a protection state, causing unnecessary energy-consumption in peripheral small-signal circuit and voltage-dividing resistors, and provides the following advantages: simple circuitry, reliable and stable consumption reduction result, without affecting response time and lifespan of circuit when circuit reactivated again, easy control and high safety. | 11-27-2014 |
20140346956 | METHOD OF FORMING A SEMICONDUCTOR DEVICE AND STRUCTURE THEREFOR - In one embodiment, a method of forming an LED control circuit may include configuring the LED control circuit to receive a sense signal that is representative of a value of an LED current flow through a plurality of LED strings wherein each LED string includes a plurality of series coupled LEDs; configuring a detector circuit of the LED control circuit to detect the LED current being no greater than a first value and responsively initiate forming a first time period; and configuring the LED control circuit to inhibit forming the LED current responsively to termination of the first time period. | 11-27-2014 |
20140354156 | LED LUMINAIRE HAVING HIGH POWER LED DRIVE CIRCUIT - An LED luminaire according to an exemplary embodiment of the present invention includes a rectifier outputting a first rectified voltage generated by rectifying AC voltage and flattening the rectified voltage, a power factor correction unit receiving the first rectified voltage output from the rectifier and generating and outputting a drive voltage, an LED light emitting unit including first to m-th light emitting groups each including at least one LED, the LED light emitting unit sequentially driven by receiving the drive voltage input from the power factor correction unit, and an LED drive IC determining a voltage level of the drive voltage upon receiving the drive voltage input from the power factor correction unit, and controlling sequential driving of the first to m-th light emitting groups according to the determined voltage level of the drive voltage. | 12-04-2014 |
20140354157 | CURRENT STEERING MODULE FOR USE WITH LED STRINGS - In an embodiment, a lamp control circuit is provided. The lamp control circuit includes an intermediate current steering block configured to be coupled to a cathode of a first light-emitting device of a plurality of light-emitting devices and a final current steering block configured to be coupled to a cathode of a final light-emitting device of the plurality of light-emitting devices. The final current steering block is configured to disable the intermediate current steering block and conduct current when a voltage input to the plurality of light-emitting devices is sufficient to activate all of the plurality of light-emitting devices. | 12-04-2014 |
20140361691 | LIGHTING SYSTEM - A lighting system includes a switch configured so that when the switch is in a first state, current from a supply flows to a light emitter, and when the switch is in a second state, current from the supply flows through the switch bypassing the light emitter. A capacitor in parallel with the light emitter provides current to the light emitter sufficient to cause the light emitter to emit light when the switch is in the second state. | 12-11-2014 |
20140375212 | MULTI-JUNCTION SOLID STATE TRANSDUCER DEVICES FOR DIRECT AC POWER AND ASSOCIATED SYSTEMS AND METHODS - Multi junction solid-state transducer (SST) devices and associated systems and methods are disclosed herein. In several embodiments, for example, an SST system can include a first multi-junction SST chain having a first drive voltage, a first P-contact, and a first N-contact, and a second multi junction SST chain having a second drive voltage, a second P-contact, and a second N-contact. The first and second multi junction SST chains can be configured to be activated independently of each other. The SST system can further include a driver operably coupled to the first and second P- and N-contacts. The driver can be configured to activate the first multi junction SST chain when voltage input is at least equal to the first drive voltage. When absolute voltage increases a predetermined voltage level, the driver can be configured to activate the second multi-junction SST chain or the first and second multi junction SST chains. | 12-25-2014 |
20140375213 | LED BACKLIGHT DRIVING CIRCUIT AND METHOD FOR DRIVING THE LED BACKLIGHT DRIVING CIRCUIT - A light emitting diode (LED) backlight driving circuit includes a plurality of LED light bars, a power supply driving the LED light bars to light, and comparing units corresponding to the LED light bars one by one. A first input end of the comparing unit is coupled to a cathode end of the LED light bar, and a second input end of the comparing unit receives a first reference voltage. Each of the LED light bars is connected in series with a switching unit, an output end of the comparing unit is coupled to a statistic unit, an output end of the statistic unit is coupled to driving units corresponding to the switching units one by one and controlling the switching units to turn on/off. The statistic unit divides the LED light bars into two groups according to a logic state output by the comparing unit, and controls the driving unit to turn off one of two groups of LED light bars having a fewer number than the other group of the LED light bars. | 12-25-2014 |
20140375214 | SYSTEMS AND METHODS FOR CONSTANT ILLUMINATION AND COLOR CONTROL OF LIGHT EMISSION DIODES IN A POLYPHASE SYSTEM - In one aspect, a light emission diode (LED) illumination system is capable of providing generally constant illumination by LED ladders coupled to power sources in a polyphase system, where each LED ladder is coupled to a power source respectively. In another aspect, a colored LED illumination system includes multi-color LEDs and is capable of controlling the color output from the LEDs. The colored LED illumination system includes a plurality of LED ladders coupled to a color-mix-control circuit. The color-mix-control circuit can control the output color of the LED ladders by adjusting the intensity of each LED ladder individually. | 12-25-2014 |
20150022089 | LIGHT-EMITTING ELEMENT DRIVING DEVICE - Short circuit failures and open circuit failures of light-emitting elements used for the backlight in an LCD panel can be reliably and easily detected. The voltage at the node between each series-connected light-emitting element array and a drive circuit is detected as a monitored voltage. A maximum detector detects the highest and a minimum detector detects the lowest of these monitored voltages. Short circuit or open circuit failure of a light-emitting element is detected by comparing the voltage difference between the maximum detector output and the minimum detector output with a specific reference voltage. | 01-22-2015 |
20150028745 | LIGHT EMITTING DIODE DRIVING CIRCUIT STRUCTURE - A light emitting diode (LED) driving circuit structure includes a surge absorber unit, a voltage suppression unit connected to the surge absorber unit, a rectifier unit electrically connected to the voltage suppression unit, a control chip connected to a fourth junction of the rectifier unit, and an impedance unit connected to the control chip. The LED driving circuit structure is installed on an LED light circuit board having a plurality of LEDs mounted thereon. According to the sinusoidal wave form of the alternating current (AC) supplied to the LEDs as well as the number and layout of the LEDs on the LED light circuit board, the LED driving circuit structure controls the current flowing through the LEDs to vary with changes of supply voltage, so as to enable effectively increased power factor and reduced harmonics, as well as effectively lowered manufacturing and material costs. | 01-29-2015 |
20150042230 | Circuit arrangement for controlling at least one load - The invention relates to a circuit arrangement ( | 02-12-2015 |
20150042231 | FAILURE MITIGATION IN ARRAYS OF LIGHT-EMITTING DEVICES - In accordance with certain embodiments, an illumination system comprising a plurality of power strings features elements facilitating compensation for failure of one or more light-emitting elements connected along each power string. | 02-12-2015 |
20150054407 | DEVICE FOR DRIVING MULTI-CHANNEL LIGHT-EMITTING DIODE - A device for driving a multi-channel light-emitting diode, includes a power supply unit for supplying power supplied from the outside; a light-emitting diode block, which is connected to a (+) terminal of the power supply unit and includes one or more light-emitting diode groups, each including at least one light-emitting diode; a current commutation unit, which is connected to a cathode of the light-emitting diode block and commutates a current flowing through the light-emitting diode groups; a reference voltage unit, which is electrically connected to the current commutation unit and provides a reference voltage to the current commutation unit; and a current driving unit for receiving power from the power supply unit, driving the light-emitting diode block through the current commutation unit, and determining a driving current flowing through the light-emitting diode groups. | 02-26-2015 |
20150061499 | LIGHT GENERATING DEVICE - A light generating device ( | 03-05-2015 |
20150084511 | Lighted sockets - An illuminated light socket is provided for powering a light bulb in a typical light string system. The illuminated socket contains its own lighting element, separate and distinct from the light bulb. The lighting element remains off when the light bulb is inserted into the socket and is illuminating properly. The lighting element illuminates when either the bulb is removed from the socket or the bulb is not illuminating correctly. The illuminated light element provides a visually perceptible warning, on the socket itself, that the associated light bulb is either absent or defective. Alternatively, a collar performing the same function is provided such that the collar may be mounted to existing light sockets. The illuminated sockets and housings may accommodate light bulbs of any technology, e.g. incandescent, LED (single or multiple color), or electroluminescent. The socket lighting element itself is preferably a low power LED or electroluminescent light. | 03-26-2015 |
20150084512 | Three-terminal LED and drive circuit thereof - A three-terminal LED and drive circuit thereof. The three-terminal LED ( | 03-26-2015 |
20150097489 | LED DRIVING DEVICE WITH OPEN CIRCUIT PROTECTION AND COLOR TEMPERATURE AND BRIGHTNESS ADJUSTMENT - An LED driving device with open circuit protection and color temperature and brightness adjustment is applied in a lamp to drive LEDs which are divided into strings, and at least one string is formed by connecting blue light diodes in series, and the remaining strings are formed by connecting yellow light LEDs in series, and at least one of the yellow light strings is connected to the blue light string in parallel and then connected to the remaining strings in series to form a node. The LED driving device employs a switch to conduct the blue or yellow light string to change the color temperature of the emitted light of the lamp, and a power input pin of a control chip is electrically coupled to the node. If there is an open circuit caused by an abnormality of the LEDs, the operation will be stopped to provide protection. | 04-09-2015 |
20150115800 | Sectioned Network Lighting Device Using Full Distribution of LED Bins - A driver circuit is configured for connection to a power source and includes a plurality of light emitting diodes (LEDs) having at least one performance characteristic that varies according to different performance categories ranging between higher performance and lower performance. The driver circuit also includes a plurality of LED sections each populated with at least one LED of a different one of the different performance categories. Circuitry is coupled to the LED sections and configured to activate and deactivate the LED sections based on LED performance. | 04-30-2015 |
20150305098 | LED DRIVING CIRCUIT FOR CONTINUOUSLY DRIVING LED, LED LIGHTING DEVICE COMPRISING SAME AND DRIVING METHOD - An exemplary embodiment discloses a light-emitting diode (LED) driving circuit including an LED driving module configured to provide a first driving voltage to an LED light emitting module including a first LED group to an n-th LED group, n is an integer which is equal to or larger than 2, and sequentially drive the first LED group to the n-th LED group depending on a voltage level of the first driving voltage and a second driving voltage providing module configured to store some of the first driving voltage and selectively provide a second driving voltage to some of the LED groups other than at least the first LED group to an m-th LED group among the LED groups in a V | 10-22-2015 |
20150305100 | DIMMING DRIVE CIRCUIT OF ALTERNATING CURRENT DIRECTLY-DRIVEN LED MODULE - Disclosed is an alternating current dimming drive circuit for an LED, comprising a rectification unit and N stages of LED direct current drive circuits. In the i | 10-22-2015 |
20150312976 | Low Power Bypass Circuit for LED Open Circuit and Reverse Polarity Protection - A low power bypass circuit for use with a string of series-connected LEDs includes a semiconductor diode and resistor connected in series, which semiconductor diode and resistor combination become conductive upon the failure of an LED or upon the improper, reverse polarity connection of the string of series-connected LEDs to a power supply. When the semiconductor and resistor combination becomes conductive, a three-terminal gate-controlled semiconductor switching device becomes conductive, thereby bypassing the failed LED and protecting the integrity of the string of series-connected LEDs upon the improper reverse polarity connection of the string of series-connected LEDs to a power supply. | 10-29-2015 |
20150312987 | LED DRIVER OPERATING FROM UNFILTERED MAINS ON A HALF-CYCLE BY HALF-CYCLE BASIS - An analog electronic circuit for driving a string of LEDs including input terminals for accepting connection to AC voltage, a current regulation circuit operatively coupled to receive an AC voltage from the input terminals and to provide an output for connection to drive the string of LEDs. Included is a current regulation circuit configured to limit the current flow through the string of LEDs on a half-cycle basis to a predetermined value. Also disclosed are an overvoltage circuit configured to switch off electrical connection between the AC voltage and the string of LEDs upon the AC reaching a predetermined high voltage value on a half-cycle basis in order to limit power. Overtemperature and power factor correction are also addressed. Also improving efficiency by shorting part of the LED string during the lower voltage phase of the input AC voltage. | 10-29-2015 |
20150341995 | Systems and Methods for Driving Light Emitting Diodes - System and methods are provided for driving one or more light emitting diodes (LEDs) to reduce audible noise. An example system includes a switching component, a system controller, and a current generator. The switching component is configured to receive a dimming signal with a predetermined dimming frequency and configured to switch on or off the one or more LEDs in response to the dimming signal, the predetermined dimming frequency being outside a frequency band of the audible noise. The system controller is configured to receive a feedback signal related to a LED current that flows through the one or more LEDs and configured to generate a drive signal. Additionally, the current generator is configured to receive the drive signal, to generate a charging current to store energy during a charging period and to generate the LED current during a discharging period. | 11-26-2015 |
20150351193 | LED Controller - Methods and circuits for controlling LEDs are disclosed. In one embodiment, a multistage driver for driving a plurality of serially connected LEDs includes a voltage regulator circuit configured to receive a rectified AC voltage, where the voltage regulator circuit includes a depletion device configured to generate a unregulated voltage using the rectified AC voltage, a band gap voltage reference circuit configured to generate a plurality of reference voltages using the unregulated voltage, and a current setting circuit configured to control the plurality of serially connected LEDs using the plurality of reference voltages. | 12-03-2015 |
20150382413 | LED LAMP WITH VARIABLE INPUT POWER SUPPLY - There is provided a light emitting diode apparatus for operation with varying input electrical sources. The apparatus comprises an array of light emitting diodes to produce light, and a variable input power supply adapted to provide an electrical supply of predetermined value to the light emitting diodes from a varying electric signal provided by varying input electrical sources. In one embodiment, the light emitting diode apparatus is for use as a replacement of a fluorescent tube in an existing fluorescent fixture. In another embodiment, the light emitting diode apparatus is for use with connection to conventional AC voltage sources used throughout the world. | 12-31-2015 |
20160037596 | Multi-Stages Power Supplying Control Circuit for Light Emitting Diode - The present invention is relates to a control circuit for LED, especially relates to a multi-stages power supplying control circuit for LED. In the present invention, a diode is set among a plurality of LED units which connect in series. A voltage detecting circuit and a plurality of switching units can be integrated to switch each switching unit after detecting the voltage of the direct current power supply. Thus, the present invention can keep the same outputting power in different input voltage. | 02-04-2016 |
20160050725 | METHODS, APPARATUSES, AND SYSTEMS FOR OPERATING LIGHT EMITTING DIODES AT LOW TEMPERATURE - Light-emitting diodes (LEDs) generate light more efficiently than high-intensity discharge lamps or high-intensity fluorescent lamps. Driving a series of LEDs with a constant-voltage primary supply and a low-voltage LED driver keeps efficiency high. Unfortunately, LED forward voltage varies as a function of temperature: at low temperature, the forward voltage rises. Placing the LEDs in series magnifies the forward voltage increases. This makes it difficult to drive a series of LEDs at low temperature with a constant-voltage supply because the forward voltage can exceed the power supply voltage. To account for this behavior, an exemplary LED lighting fixture includes a “bypass” circuit that, when engaged, effectively removes at least one LED from each series string of LEDs to bring the total forward voltage below the power supply voltage. The low-voltage driver circuit monitors temperature, and engages the “bypass” circuit when necessary to ensure that DC voltage is not exceeded. | 02-18-2016 |
20160050739 | DC OPERATED CHRISTMAS LIGHT STRING - A string set of series-connected incandescent bulbs in which the bulbs are individually provided with a voltage responsive shunt which is inoperative during normal operation of the string set when connected to a source of operating potential and which becomes operative only in response to an increase in the voltage thereacross which exceeds its rating, and in which the remaining bulbs of the circuit continue to receive rated current therethrough and rated voltage thereacross and further continue to be illuminated even though other bulbs in the string are either inoperative or are missing from their respective sockets. The string includes a split bridge AC to DC converter which provides pulsating DC current to the shunted, series-connected incandescent bulbs. | 02-18-2016 |
20160079865 | SWITCHING POWER SUPPLY DEVICE AND PROJECTION VIDEO DISPLAY DEVICE - A switching power supply device includes a transformer which includes a secondary winding divided into a plurality of winding units, a resonant capacitor, and a first switching element and a second switching element. Further, the switching power supply device includes a plurality of rectifier diodes which extracts voltages induced to the secondary winding in the winding units, an output voltage switching circuit which switches the voltages extracted from the plurality of rectifier diodes and outputs a switched voltage, a current detection circuit which detects a current flowing in a load circuit, and a controller which controls the output voltage switching circuit based on a detection result of the current detection circuit. | 03-17-2016 |
20160100464 | AC-POWERED LED LIGHT ENGINE - AC LED light engines powered directly from the AC power line contain circuitry of resistors, capacitors, diodes and transistors which enables an array of LEDs to efficiently produce light with a relatively low level of flicker as perceived by the human eye. The LEDs are driven by a current which is alternately capacitively limited and resistively-limited. Capacitively-limited pulses of current are combined with resistively-limited pulses of current so that the resulting output current ripple is at frequencies of 240 Hz or above which the human eye cannot perceive. The combination of resistively-limited current and capacitively-limited current results in a current drain from the power line which is generally sinusoidal and can have a power factor in excess of 0.90, and a flicker index below 0.2. | 04-07-2016 |
20160119990 | LOW COST LED DRIVER WITH INTEGRAL DIMMING CAPABILITY - A distributed system for driving strings of series-connected LEDs for backlighting, display and lighting applications that includes multiple intelligent satellite LED driver ICs connected to an interface IC via a serial lighting interface bus. The interface IC translates information obtained from a host microcontroller into instructions for the satellite LED driver ICs pertaining to such parameters as duty factor, current levels, phase delay and fault settings. Fault conditions in the LED driver ICs can be transmitted back to the interface IC. An analog current sense feedback system which also links the LED driver ICs determines the supply voltage for the LED strings. | 04-28-2016 |
20160143095 | CIRCUITS FOR DRIVING LIGHT SOURCES - A light source driving circuit for powering a first light source and a second light source by a DC voltage includes a first current regulator, a second current regulator and a controller. The first current regulator controls a first switch coupled to the first light source based on a first current reference and a first sensing signal. The second current regulator controls a second switch coupled to the second light source based on a second current reference and a second sensing signal. The controller regulates the current through the first light source and the current through the second light source by controlling the first current regulator and the second current regulator. If the DC voltage is within a first range, then the controller turns on the first light source. If the DC voltage is within a second range, then the controller turns on the first light source and the second light source. | 05-19-2016 |
20160143099 | LIGHT STRING - The present invention provides a light string including at least one light series branch and a protecting circuit connected between the at least one light series branch and an AC power supply. The protecting circuit includes a switching circuit, a sample circuit and a control circuit for switching off the switching circuit and keeping the switching circuit at off-state when the sampled voltage is larger than or equal to a preset voltage, and controlling the switching circuit to turn on and turn off the at least one light series branch. When the number of the failed lamps and removed lamps reaches to a preset number, the current is opened to protecting the reminder light from been burned out. The light string can light on and off alternately like twinkling stars, or the colors can be changed alternately. | 05-19-2016 |
20160150604 | Reduction of Harmonic Distortion for LED Loads - Apparatus and associated methods reduce harmonic distortion of a excitation current by diverting the excitation current substantially away from a number of LEDs arranged in a series circuit until the current or its associated periodic excitation voltage reaches a predetermined threshold level, and ceasing the current diversion while the excitation current or voltage is substantially above the predetermined threshold level. In an illustrative embodiment, a rectifier may receive an AC (e.g., sinusoidal) voltage and deliver unidirectional current to a string of series-connected LEDs. An effective turn-on threshold voltage of the diode string may be reduced by diverting current around at least one of the diodes in the string while the AC voltage is below a predetermined level. In various examples, selective current diversion within the LED string may extend the input current conduction angle and thereby substantially reduce harmonic distortion for AC LED lighting systems. | 05-26-2016 |
20160150615 | METHOD AND APPARATUS FOR PROVIDING A PASSIVE COLOR CONTROL SCHEME USING BLUE AND RED EMITTERS - A lighting device capable of generating warm or neutral white light using blue light-emitting diodes (“LEDs”), red LEDs, and/or luminescent material that responds to blue LED emission is disclosed. The lighting device includes multiple first solid-state light-emitting structures (“SLSs”), second SLSs, and balancing resistor element. The first SLS such as a string of blue LED dies connected in series is able to convert electrical energy to blue optical light, which is partially turned into longer wavelength emission by the luminescent material. The second SLS such as a red LED die is configured to convert electrical energy to red optical light, wherein the second SLSs are connected in series. While the first SLSs and second SLSs are coupled in parallel, the balancing resistor element provides load balance for current redistribution between the first and second SLSs in response to fluctuation of operating temperature. | 05-26-2016 |
20160183334 | BACKLIGHT UNIT AND DISPLAY DEVICE INCLUDING BACKLIGHT UNIT | 06-23-2016 |
20160183336 | LIGHT EMITTING MODULE | 06-23-2016 |
20160205742 | ILLUMINATION SYSTEM AND LUMINAIRE | 07-14-2016 |
20160381756 | SPECTRAL SHIFT CONTROL FOR DIMMABLE AC LED LIGHTING - Apparatus and associated methods involve operation of an LED light engine in which a relative intensities of selected wavelengths shift as a function of electrical excitation. In an illustrative example, current may be selectively and automatically diverted substantially away from at least one of a number of LEDs arranged in a series circuit until the current or its associated periodic excitation voltage reaches a predetermined threshold level. The diversion current may be smoothly reduced in transition as the excitation current or voltage rises substantially above the predetermined threshold level. A color temperature of the light output may be substantially changed as a predetermined function of the excitation voltage. For example, some embodiments may substantially increase or decrease a color temperature output by a solid state light engine in response to dimming the AC voltage excitation (e.g., by phase-cutting or amplitude modulation). | 12-29-2016 |
20160381773 | SEMICONDUCTOR LIGHT SOURCE DRIVING APPARATUS - The semiconductor light source driving apparatus includes light source modules, a current control element, a second current detection element, a DC power supply, and a controller. The light source modules each include the following components connected in parallel: a semiconductor light source; a first constant-voltage diode; a series circuit of a first current detection element and a second constant-voltage diode with a lower breakdown voltage than the first constant-voltage diode; and a switching element. The controller controls the DC power supply based on a detection output of the second current detection element. After the first current detection element generates a output in response to an open fault in any of the semiconductor light sources, and then the current control element is turned off, the controller turns on the switching element of the light source module with the open fault, thereby allowing the current control element to be controlled. | 12-29-2016 |