| Patent application number | Description | Published |
|---|
| 20080224629 | LIGHTING SYSTEM WITH POWER FACTOR CORRECTION CONTROL DATA DETERMINED FROM A PHASE MODULATED SIGNAL - A light emitting diode (LED) lighting system includes a power factor correction (PFC) controller that determines at least one power factor correction control parameter from phase delays of a phase modulated signal. In at least one embodiment, a peak voltage of the phase modulated signal is a PFC control parameter used bit the PFC controller to control power factor correction and generation of a link voltage by a PFC LED driver circuit. The phase delays are related to a peak voltage of the phase modulated signal. Thus, in at least one embodiment, detecting the phase delay in one or more cycles of the phase modulated signal allows the PFC controller to determine the peak voltage of the phase modulated signal. | 09-18-2008 |
| 20080224631 | Color variations in a dimmable lighting device with stable color temperature light sources - A method and system allow a lighting device having light sources with multiple color temperatures to vary a color temperature of the lighting device in response to changing dimming levels. The light sources are non-incandescent light sources, such as light emitting diodes and/or gas-discharge lights. A dimmer circuit provides a dimming signal that indicates a selected dimming level. The lighting device includes a light source driver and a light source driver controller that cooperate to vary drive currents to the light sources in response to the selected dimming level. By varying the drive currents in different relative amounts, the color temperature of the lighting device changes in response to dimming level changes. In at least one embodiment, changes in the color temperature of the lighting device in response to the dimming level changes simulates the color temperature changes of an incandescent light source. | 09-18-2008 |
| 20080224633 | Lighting System with Lighting Dimmer Output Mapping - A system and method map dimming levels of a lighting dimmer to light source control signals using a predetermined lighting output function. The dimmer generates a dimmer output signal value. At any particular period of time, the dimmer output signal value represents one of multiple dimming levels. In at least one embodiment, the lighting output function maps the dimmer output signal value to a dimming value different than the dimming level represented by the dimmer output signal value. The lighting output function converts a dimmer output signal values corresponding to measured light levels to perception based light levels. A light source driver operates a light source in accordance with the predetermined lighting output function. The system and method can include a filter to modify at least a set of the dimmer output signal values prior to mapping the dimmer output signal values to a new dimming level. | 09-18-2008 |
| 20080224636 | POWER CONTROL SYSTEM FOR CURRENT REGULATED LIGHT SOURCES - A light emitting diode (LED) lighting system includes a PFC and output voltage controller and a LED lighting power system. The controller advantageously operates from an auxiliary voltage less than a link voltage generated by the LED lighting power system. The common reference voltage allows all the components of lighting system to work together. A power factor correction switch and an LED drive current switch are coupled to the common reference node and have control node-to-common node, absolute voltage that allows the controller to control the conductivity of the switches. The LED lighting system can utilize feed forward control to concurrently modify power demand by the LED lighting power system and power demand of one or more LEDs. The LED lighting system can utilize a common current sense device to provide a common feedback signal to the controller representing current in at least two of the LEDs. | 09-18-2008 |
| 20080272744 | POWER CONTROL SYSTEM USING A NONLINEAR DELTA-SIGMA MODULATOR WITH NONLINEAR POWER CONVERSION PROCESS MODELING - A power control system includes a switching power converter and a power factor correction (PFC) and output voltage controller. The switching power converter utilizes a nonlinear energy transfer process to provide power to a load. The PFC and output voltage controller generates a control signal to control power factor correction and voltage regulation of the switching power converter. The PFC and output voltage controller includes a nonlinear delta-sigma modulator that models the nonlinear energy transfer process of the switching power converter. The nonlinear delta-sigma modulator generates an output signal used to determine the control signal. By using the nonlinear delta-sigma modulator in a control signal generation process, the PFC and output voltage controller generates a spectrally noise shaped control signal. In at least one embodiment, noise shaping of the control signal improves power factor correction and output voltage regulation relative to conventional systems. | 11-06-2008 |
| 20080272745 | POWER FACTOR CORRECTION CONTROLLER WITH FEEDBACK REDUCTION - A power control system includes a feedback loop having a power factor correction (PFC) and output voltage controller and a switching power converter. The switching power converter includes an inductor to supply charge to an output capacitor and a switch to control inductor current ramp-up times. The PFC and output voltage controller provides a control signal to the switch to control PFC and regulate output voltage of the switching power converter. During a single period of the control signal, the PFC and output voltage controller obtains the line input voltage and output voltage of the switching power converter using a single feedback signal received from the switching power converter. | 11-06-2008 |
| 20080272746 | POWER FACTOR CORRECTION CONTROLLER WITH SWITCH NODE FEEDBACK - A power control system includes a switching power converter and a power factor correction (PFC) and output voltage controller. The PFC and output voltage controller provides a control signal to a switch to control power factor correction and regulate output voltage of the switching power converter. During a single period of the control signal, the PFC and output voltage controller determines the line input voltage, the output voltage, or both using a single feedback signal received from the switching power converter. The feedback signal is received from a switch node located between an inductor and the switch. The PFC and output voltage controller determines either the line input voltage or the output voltage, whichever was not determined from the feedback signal, using a second feedback signal received from either a PFC stage or a driver stage of the switching power converter. | 11-06-2008 |
| 20080272747 | PROGRAMMABLE POWER CONTROL SYSTEM - A power control system includes a switching power converter and a programmable power factor correction (PFC) and output voltage controller. The programmable PFC and output voltage controller generates a control signal to control power factor correction and voltage regulation of the switching power converter. In at least one embodiment, the control signal is a pulse width modulated signal. The programmability of the PFC and output voltage controller provides the programmable PFC and output voltage controller flexibility to operate in accordance with programmable parameters, to adapt to various operating environments, and to respond to various operating exigencies. In at least one embodiment, the programmable PFC and output voltage controller includes a state machine to process one or more programmable, operational parameters to determine the period and pulse width states of the control signal. | 11-06-2008 |
| 20080272755 | SYSTEM AND METHOD WITH INDUCTOR FLYBACK DETECTION USING SWITCH GATE CHARGE CHARACTERISTIC DETECTION - A method and system monitor gate charge characteristics of one or more field effect transistors in a switching power converter to detect an end of an inductor flyback time interval. The switching power converter includes a switch coupled to an inductor to control current flow in the inductor. When the switch turns OFF, a collapsing magnetic field causes the inductor current to decrease and the inductor voltage to reverse polarity. When the magnetic field completely collapses, the inductor current goes to zero. At the end of the inductor flyback time interval, a voltage is induced across a Miller capacitance of the switch. The voltage can be detected as a transient change in the gate voltage of the switch. A switch gate sensor detects the gate voltage change associated with the end of the inductor flyback time interval and provides a signal indicating an end of the inductor flyback time interval. | 11-06-2008 |
| 20080272756 | POWER FACTOR CORRECTION CONTROLLER WITH DIGITAL FIR FILTER OUTPUT VOLTAGE SAMPLING - A power control system includes a digital FIR filter in an output voltage feedback loop of a switching power converter. A feedback loop includes an output voltage signal of the switching power converter. The output voltage signal includes direct current (DC) and alternating current (AC) components. The FIR filter provides discrete samples of an output voltage feedback signal to a switch state controller that allows the switch state controller to generate a control signal that reflects a relatively quick response to changes in the output voltage signal while reducing an influence of the AC component. In at least one embodiment, the FIR filter is configured to generate the discrete samples at a sampling frequency f | 11-06-2008 |
| 20080272757 | POWER SUPPLY DC VOLTAGE OFFSET DETECTOR - A power supply output voltage direct current (DC) offset detector determines a DC offset in a power supply output voltage signal, and the output voltage signal has a DC component and an alternating current (AC) “ripple” component. Once during each period of the ripple, the DC offset detector determines the DC offset from an output voltage signal using a comparison between the output voltage signal and a reference voltage. In at least one embodiment, from the comparison and during a period of the ripple, the DC offset detector determines an ‘above’ duration for which the ripple is above the reference voltage, determines a ‘below’ duration for which the ripple is below the reference voltage, or both to determine the DC offset of the power supply output voltage signal. The DC offset detector uses the above and/or below duration(s) to determine the DC offset of the output voltage signal. | 11-06-2008 |
| 20080272758 | Switching Power Converter with Switch Control Pulse Width Variability at Low Power Demand Levels - A power control system includes a switch mode controller to control the switching mode of a switching power converter. The switch mode controller generates a switch control signal that controls conductivity of a switch of the switching power converter. Controlling conductivity of the switch controls the switch mode of the switching power converter. The switch mode controller includes a period generator to determine a period of the switch control signal and to vary the determined period to generate a broad frequency spectrum of the switch control signal when the determined period corresponds with a frequency in at least a portion of an audible frequency band. Generating a switch control signal with a broad frequency spectrum in the audible frequency band allows the system to utilize switching frequencies in the audible frequency band. | 11-06-2008 |
| 20080272945 | CONTROL SYSTEM USING A NONLINEAR DELTA-SIGMA MODULATOR WITH NONLINEAR PROCESS MODELING - A control system includes a nonlinear delta-sigma modulator, and the nonlinear delta-sigma modulator includes a nonlinear process model that models a nonlinear process in a signal processing system, such as a nonlinear plant. The nonlinear delta-sigma modulator includes a feedback model that models the nonlinear process being controlled and facilitates spectral shaping to shift noise out of a baseband in a spectral domain of a response signal of the nonlinear process. In at least one embodiment, the nonlinear delta-sigma modulator is part of a control system that controls power factor correction and output voltage of a switching power converter. The control system controls the pulse width and period of a control signal to control power factor correction and the output voltage level. In at least one embodiment, the nonlinear delta-sigma modulator generates a signal to control the pulse width of the control signal. | 11-06-2008 |
| 20080272946 | SIGNAL PROCESSING SYSTEM USING DELTA-SIGMA MODULATION HAVING AN INTERNAL STABILIZER PATH WITH DIRECT OUTPUT-TO-INTEGRATOR CONNECTION - A signal processing system includes an analog-to-digital delta sigma modulator with a duty cycle modulator and a finite impulse response (FIR) filter in a main loop feedback path of the delta sigma modulator. The duty cycle modulator and FIR filter can provide high performance filtering in the main loop feedback path. To prevent instability in the main loop caused by the duty cycle modulator and FIR filter, the delta sigma modulator also includes a stabilizer loop. Transfer functions of the main loop and the stabilizer loop combine to achieve a target transfer function for the analog-to-digital delta sigma modulator that provides for stable operation of the analog-to-digital delta sigma modulator. In at least one embodiment, the stabilizer loop includes a stabilizer path that provides output data directly to an integrator of the main loop filter. | 11-06-2008 |
| 20080273356 | Switching Power Converter with Efficient Switching Control Signal Period Generation - A power control system includes a switching power converter and a controller, and the controller responds to a time-varying voltage source signal by generating a switch control signal having a period that varies in accordance with at least one of the following: (i) the period of the switch control signal trends inversely to estimated power delivered to a load coupled to the switching power converter, (ii) the period of the switch control signal trends inversely to instantaneous voltage levels of the voltage source signal, and (iii) the period of the switch control signal trends directly with a line voltage level of the time-varying voltage source signal. In at least one embodiment, the controller achieves an efficient correlation between the switching period with associated switching losses and the instantaneous power transferred to the switching power converter while providing power factor correction (PFC). | 11-06-2008 |
| 20080315791 | HYBRID GAS DISCHARGE LAMP-LED LIGHTING SYSTEM - A lighting system and method combine at least one LED and at least one gas discharge lamp within a common housing. The lighting system includes a control system to dependently operate each LED and each gas discharge lamp during overlapping, non-identical periods of time. In at least one embodiment, the control system can provide light output by activating LEDs during gas discharge preheating operations and thus extend the useful life of each gas discharge lamp. When dimming the lighting system, the control system can reduce current to the gas discharge lamps and one or more gas discharge lamps can be phased out as dimming levels decrease. As dimming levels decrease, one or more of the LEDs can be activated or groups of LEDs can be phased in to replace the light output of the dimmed gas discharge lamps. Thus, the lighting system can reduce power consumption at low dimming levels. | 12-25-2008 |
| 20090085625 | TIME-BASED CONTROL OF A SYSTEM HAVING INTEGRATION RESPONSE - A time-based controller provides control for a controlled system including a plant having an integration response. The time-based controller includes a comparator that detects a polarity change in a comparison of a sensed signal from the plant and a reference signal while a control signal is in a first state, time calculation logic that, responsive to detection of the change in the comparison, determines a time at which to change a state of a control signal supplied to the plant, and a modulator that, at the determined time, changes the state of the control signal supplied to the plant from the first state to a second state. | 04-02-2009 |
| 20090085657 | COMPENSATION OF FIELD EFFECT ON POLYCRYSTALLINE RESISTORS - A resistive circuit includes a first terminal and a second terminal and polycrystalline first and second resistive segments coupled between the first and second terminals. A third terminal A is coupled to the first resistive segment, and a third terminal B is coupled to the second resistive segment. The third terminal A has a first voltage with respect to the first terminal, and the third terminal B has a second voltage with respect to the second terminal. With this arrangement, the non-linearity of resistance of the first resistive segment at least partially compensates for non-linearity of resistance of the second resistive segment. | 04-02-2009 |
| 20090147544 | MODULATED TRANSFORMER-COUPLED GATE CONTROL SIGNALING METHOD AND APPARATUS - A modulated transformer-coupled gate control signaling method and apparatus provides reduction of circuit complexity and robust design characteristics in switching power circuits having a transformer-coupled gate drive. A modulated control signal at a rate substantially higher than the switching circuit gate control rate is provided from the controller circuit to a demodulator via transformer coupling. Power for the demodulator can be obtained by rectifying the modulated control signal at the demodulator, or from another transformer winding. The modulation scheme is chosen to have a DC average value of zero, eliminating any magnetization current management requirements. The modulated control signal may carry redundant control information and/or may encode additional information to provide a more sophisticated gate drive control, such as oversampled gate control information. | 06-11-2009 |
| 20090147545 | HISTORY-INDEPENDENT NOISE-IMMUNE MODULATED TRANSFORMER-COUPLED GATE CONTROL SIGNALING METHOD AND APPARATUS - A history-independent and noise-immune modulated transformer-coupled gate control signaling method and apparatus provides robust design characteristics in switching power circuits having a transformer-coupled gate drive. A modulated control signal at a rate substantially higher than the switching circuit gate control rate is provided from the controller circuit to a demodulator via transformer coupling. Codes specified by relative timing of transitions in multiple periods of the modulated control are assigned to gate-on and gate-off timing events that control the switching transistor gate(s) and unassigned patterns are decoded as gate-off events, reducing the possibility that a switching transistor will be erroneously activated due to noise. The modulated signal is constructed so that signal history is not required for decoding, eliminating any requirement of a reference clock. Blanking may be employed to conserve power between codes and to avoid mis-triggering due to noise events during power switching. | 06-11-2009 |
| 20090189579 | SWITCH STATE CONTROLLER WITH A SENSE CURRENT GENERATED OPERATING VOLTAGE - A power supply system and method includes a switch state controller that is operational to control a switching power converter during certain power loss conditions that cause conventional switch state controllers to have diminished or no functionality. In at least one embodiment, during certain power loss conditions, such as when an auxiliary power supply is in standby mode or when the switching power converter is not operating, a power supply for the switch state controller does not provide sufficient operating power to the switch state controller during certain power loss conditions. In at least one embodiment, during such power loss conditions power is generated for the switch state controller using sense input and/or sense output currents of the switching power converter to allow an integrated circuit (IC) switch state controller to generate a control signal to control a switch of the switching power converter. | 07-30-2009 |
| 20090190379 | SWITCHING REGULATOR WITH BOOSTED AUXILIARY WINDING SUPPLY - A boosted auxiliary winding power supply for a switched-power converter circuit provides operating voltage for control and other circuits early in the start-up phase of converter operation. A boost circuit has an input coupled to the auxiliary winding to boost the voltage available from the auxiliary winding at least during start-up of the switched-power converter. The boost thereby provides a voltage that is greater than the voltage across the auxiliary winding during start-up of the switched-power converter. The boost circuit may be actively switched at a rate higher than a switching rate of the switched-power converter, to increase a rate of rise of the operating voltage. Polarity information, which may be provided from the switched-power converter control circuit, can be used to actively rectify the output of the auxiliary winding. | 07-30-2009 |
| 20090190384 | POWERING A POWER SUPPLY INTEGRATED CIRCUIT WITH SENSE CURRENT - A power control system and method senses input and/or output voltages of a power supply using sense currents in order for an integrated circuit (IC) switch state controller to generate a control signal to control a switch of the power control system. By sensing sense currents, the power control system can eliminate at least one sense resistor used in a voltage sense system. The sense current(s) can be used to provide power and sensing to the switch state controller. In at least one embodiment, the sense current(s) provide power to the switch state controller when auxiliary IC power is unavailable or diminished, such as during start-up of the IC. In at least one embodiment, the IC draws more sense current from an input of the power control system than the output of the power control system to, for example, minimize impact on the output voltage of the power supply. | 07-30-2009 |
| 20090191837 | Delta Sigma Modulator with Unavailable Output Values - A power control system includes a delta sigma modulator to generate output values for use in controlling a switching power converter. In at least one embodiment, the delta sigma modulator includes two ranges of available output values and a range of one or more unavailable intermediate output values, wherein the range of one or more unavailable intermediate output values represent a gap in available output values. Each unavailable intermediate output value represents an output value that is not generated by the delta sigma modulator. In at least one embodiment, the delta sigma modulator includes a quantizer output remapping module that remaps quantizer output values within the range of one or more unavailable intermediate output values of the delta sigma modulator to new output values within one of the ranges of available output values. | 07-30-2009 |
| 20090212759 | TRANSFORMER-ISOLATED ANALOG-TO-DIGITAL CONVERTER (ADC) FEEDBACK APPARATUS AND METHOD - A transformer-isolated analog-to-digital converter (ADC) feedback apparatus and method provides reduction of circuit complexity in high power/high voltage systems having a transformer-isolated sensing circuit. The feedback apparatus is a circuit including an ADC for receiving an analog input signal and a transformer having a first winding that receives a modulated output of the analog-to-digital converter. A second winding of the transformer provides an isolated data output of the ADC. A demodulator is coupled to the second winding of the transformer and demodulates the isolated output to generate a digital representation of the analog input signal. The ADC may be a delta-sigma converter and the demodulator may be the corresponding decimation filter. The circuit further includes an isolation circuit for introducing a clock signal and/or power supply waveform at the second winding of the transformer, so that the ADC circuit is supplied with an isolated clock and/or an isolated power supply. | 08-27-2009 |
| 20090243591 | POWER METER HAVING COMPLEX QUADRATURE OUTPUT CURRENT AND VOLTAGE FILTERS - A power meter having complex quadrature output current and voltage filters provides power measurements in high amplitude and frequency variation and/or high jitter environments without requiring high computational overhead. A pair of filters, one for voltage and one for current each have a response determined by complex non-conjugate poles. The response of the filters is such that only the positive or negative half plane of the complex frequency spectrum is passed and provide complex outputs representing the real and imaginary parts of both the current and voltage. At least one indication of a power delivered to a load is computed from the complex current and voltage outputs, which may be the real and/or reactive power. | 10-01-2009 |
| 20090278720 | DELTA-SIGMA ANALOG-TO-DIGITAL CONVERTER CIRCUIT HAVING REDUCED SAMPLED REFERENCE NOISE - A delta-sigma analog-to-digital converter (ADC) circuit improves performance by reducing the amount of noise and other error sampled by the reference switching circuit. The reference switching network is operated intermittently only when the charge on an input integrator exceeds a threshold, thereby preventing the input integrator from saturating, while avoiding needlessly injecting reference noise. The input to the ADC may be a current injected directly into a summing node of the integrator, or may be a voltage supplied through another switching network. | 11-12-2009 |
| 20090310941 | AUDIO CLOCKING IN VIDEO APPLICATIONS - A method of operating an electronic video device such as a DVD player, wherein video clock signals and audio clock signals are derived from a system clock signal using two phase-lock loops, and these video and audio clock signals are used to process encoded video data and encoded audio data, but digital-to-analog conversion of the audio data stream is controlled by the system clock signal rather than the audio clock signals. By using the system clock signal to control the audio digital-to-analog converter (DAC), the DAC avoids the poor performance issues that can arise from jitter introduced into the audio clock signals by the PLL. The system clock signal may be divided by an integer to generate the sampling clock for the audio DAC. In the illustrative embodiment, the system clock signal has a rate which is not an integer multiple of the sample rate of the audio data stream. | 12-17-2009 |
| 20090322300 | HYSTERETIC BUCK CONVERTER HAVING DYNAMIC THRESHOLDS - A hysteretic buck converter provides improved regulation control, in particular for buck converter standby operation. A comparison circuit compares the output voltage of the buck converter to a waveform that is generated from an indication of the output current of the converter, so that the turn-on time of the converter is advanced as the output current demand increases. The resulting action anticipates a reduction in output voltage due to the increased current, preventing an excursion of the output voltage below the ripple voltage minimum. The turn-off time of the converter is controlled by an upper threshold that limits the ripple voltage maximum. The output current indication may be a measurement of output current, or may be a dynamic value calculated from the input voltage and the output voltage waveform. | 12-31-2009 |
| 20100013050 | Compensation Of Field Effect On Polycrystalline Resistors - A resistive circuit includes a first terminal and a second terminal and polycrystalline first and second resistive segments coupled between the first and second terminals. A third terminal A is coupled to the first resistive segment, and a third terminal B is coupled to the second resistive segment. The third terminal A has a first voltage with respect to the first terminal, and the third terminal B has a second voltage with respect to the second terminal. With this arrangement, the non-linearity of resistance of the first resistive segment at least partially compensates for non-linearity of resistance of the second resistive segment. | 01-21-2010 |
| 20100019874 | Transformer With Split Primary Winding - A transformer includes a core having a first leg, a second leg and a third leg, a split primary winding including first turns about the first leg electrically coupled with second turns about the third leg, and a secondary winding about the second leg. Magnetic flux linking the first turns of the split primary winding and magnetic flux linking the second turns of the primary winding link the secondary winding. | 01-28-2010 |
| 20100020569 | RESONANT SWITCHING POWER CONVERTER WITH ADAPTIVE DEAD TIME CONTROL - A resonant switching power converter having adaptive dead time control provides improved efficiency along with reduced EMI/audible noise and component stresses. A dead time between pulses generated by a switching circuit is adaptively set in conformity with a value of the input voltage to the resonant switching power converter and an indication of a magnitude of the current passing through inductive element of the resonant tank of the converter. The indication of the current magnitude may be the switching frequency of the converter, or a measure of line or load current levels. The dead time can be obtained from a look-up table or computed from the current magnitude and input voltage values. | 01-28-2010 |
| 20100020570 | RESONANT SWITCHING POWER CONVERTER WITH BURST MODE TRANSITION SHAPING - A resonant switching power converter having burst mode transitioning operates during low or zero load conditions with reduced audible noise and component stresses, while improving efficiency. Pulse bursts are generated with a beginning and/or ending pulse duration that differs from mid-burst pulse durations, in order to reduce an amplitude of transients otherwise generated at the beginning and/or end of the bursts. Alternatively, the spacing between the pulses at the beginning and/or end of the bursts may differ from the spacing between the pulses in the middle of the bursts to reduce the transient(s). A number of pulses at the beginning and/or end of the burst can also be set with gradually varying durations, to further reduce component stress and audible vibration in a transformer that couples the resonant tank to the output of the converter. | 01-28-2010 |
| 20100020573 | AUDIBLE NOISE SUPPRESSION IN A RESONANT SWITCHING POWER CONVERTER - Audible noise in resonant switching power converter during low-power burst mode operation is reduced by spreading the spectrum generated by the bursts, thereby reducing the amplitude of audio spectrum peaks in the current supplied through the resonant tank from a switching circuit. The spreading can be accomplished by varying the intervals between the bursts and/or by varying a pulse pattern within the bursts. The pulse pattern within the bursts can be varied by varying the number of pulses in the bursts, the polarity of the initial pulse of the bursts, and/or the duration of pulses within the bursts either uniformly or randomly. The burst pulse pattern may also be selected in alternation from a set of pulse patterns stored in a memory and the selection may be made randomly or systematically. | 01-28-2010 |
| 20100020579 | Power Supply With Accurate Energy Measurement - A power supply includes a rectifier having an AC input and a DC output and a power factor correction (PFC) preregulator, coupled to the rectifier, that increases a power factor of the power supply. The PFC preregulator includes a controller that integrates an input power to determine energy consumption and outputs a signal indicative of the energy consumption. | 01-28-2010 |
| 20100060202 | Lighting System with Lighting Dimmer Output Mapping - A system and method map dimming levels of a lighting dimmer to light source control signals using a predetermined lighting output function. The dimmer generates a dimmer output signal value. At any particular period of time, the dimmer output signal value represents one of multiple dimming levels. In at least one embodiment, the lighting output function maps the dimmer output signal value to a dimming value different than the dimming level represented by the dimmer output signal value. The lighting output function converts a dimmer output signal values corresponding to measured light levels to perception based light levels. A light source driver operates a light source in accordance with the predetermined lighting output function. The system and method can include a filter to modify at least a set of the dimmer output signal values prior to mapping the dimmer output signal values to a new dimming level. | 03-11-2010 |
| 20100079125 | Current sensing in a switching power converter - A power control system includes a current sense resistor located on an output side of a switching power converter. By locating the current sense resistor on the output side of the switching power converter, the current sense resistor conducts a sense current when a control switch of the switching power converter is nonconductive. Since a duty cycle of the control switch is larger for a low input voltage than for a higher input voltage, the current sense resistor conducts current for a shorter time duration for low input voltages than for higher input voltages. Thus, the root mean square (RMS) of a sense current in the current sense resistor and, thus, power dissipation by the current sense resistor, is lower during low input voltages than power dissipation in conventionally located current sense resistors. The RMS of the sense current is approximately constant across a full range of input voltages. | 04-01-2010 |
| 20100148677 | TIME DIVISION LIGHT OUTPUT SENSING AND BRIGHTNESS ADJUSTMENT FOR DIFFERENT SPECTRA OF LIGHT EMITTING DIODES - In at least one embodiment, brightness multiple LEDs is adjusted by modifying power to subgroups of the multiple LEDs during different times and detecting the brightness of the LEDs during the reductions of power. In at least one embodiment, once the brightness of the LEDs are determined, a controller determines if the brightness meet target brightness values, and, if not, the controller adjusts each LED with the goal meet the target brightness values. In at least one embodiment, a process of modifying power to the subgroups of multiple LEDs over time and adjusting the brightness of the LEDs is referred as “time division and light output sensing and adjusting. Thus, in at least one embodiment, a lighting system includes time division light output sensing and adjustment for different spectrum light emitting diodes (LEDs). | 06-17-2010 |
| 20100164406 | SWITCHING POWER CONVERTER CONTROL WITH TRIAC-BASED LEADING EDGE DIMMER COMPATIBILITY - In at least one embodiment, a controller allows triac-based dimmer to properly function and dim a load whose voltage is regulated by a switching power converter. In at least one embodiment, the switching power converter includes a switch to control voltage conversion of an input voltage to the switching power converter, wherein phase delays are introduced in the input voltage by a triac-based dimmer during a dimming period. In at least one embodiment, the controller is configured to control the switch of the switching power converter to establish an input resistance of the switching power converter during a dimming portion of the input voltage, wherein the input resistance allows the triac-based dimmer to phase modulate a supply voltage to the dimmer so that an output voltage of the dimmer has a substantially uninterrupted phase delay during each half-cycle of the supply voltage during the dimming period. | 07-01-2010 |
| 20100164631 | ELECTRONIC SYSTEM HAVING COMMON MODE VOLTAGE RANGE ENHANCEMENT - An electronic system generates at least one floating supply voltage, wherein during operation of the circuit the floating supply voltage tracks a common mode voltage of first and second differential input signals. By tracking the common mode voltage, in at least one embodiment, the floating supply voltage adjusts as the common mode voltage changes. Thus, the floating supply voltages can be based upon the peak-to-peak values of the first and second output signals without factoring in the common mode voltage. In at least one embodiment, the electronic system provides the floating supply voltages to an amplifier. The amplifier amplifies the first and second differential input signals and generates differential output signals. A differential sampling circuit samples the differential output signals to cancel the common mode voltage from the differential output signals. In at least one embodiment, an analog-to-digital converter converts the sampled differential output signals into a digital output signal. | 07-01-2010 |
| 20100171442 | Light Emitting Diode Based Lighting System With Time Division Ambient Light Feedback Response - A lighting system includes time division light output sensing and adjustment for ambient light. In at least one embodiment, time division light output sensing involves modulating power to a light emitting diode (LED) set, and the set of LEDs includes one or more LEDs. In at least one embodiment, each LED in the LED set is included in a single lamp, and, in at least one embodiment, the set of LEDs is contained in multiple lamps. In at least one embodiment, for each lamp, a controller modulates power to the LED set by selectively reducing power to the LED set using time division algorithm to allow a light sensor to sense the brightness of ambient light with a reduced contribution from the LED set. In at least one embodiment, a lighting system also includes time division light output sensing and adjustment for different spectra LEDs. | 07-08-2010 |
| 20100244726 | PRIMARY-SIDE BASED CONTROL OF SECONDARY-SIDE CURRENT FOR A TRANSFORMER - A power control system includes a transformer and a controller regulates a current on a secondary-side of the transformer based on a primary-side signal value. In at least one embodiment, the secondary-side current is a current out of a filter coupled to a rectifier and the secondary-side of the transformer and into a load. In at least one embodiment, the primary-side signal value is a sample of a current in the primary-side windings of the transformer. In at least one embodiment, the primary-side signal value represents a sample value of a primary-side transformer current. Proper timing of sampling the primary-side signal value substantially eliminates contributions of a transformer magnetizing current from the primary-side transformer current sample. Sampling the primary-side signal value when contributions of the transformer magnetizing current are substantially eliminated allows at least an average of the secondary-side current to be determined from the primary-side signal value. | 09-30-2010 |
| 20100253305 | SWITCHING POWER CONVERTER CONTROL WITH SPREAD SPECTRUM BASED ELECTROMAGNETIC INTERFERENCE REDUCTION - Power control systems generate electromagnetic interference (EMI). In at least one embodiment, a power control system includes a switching power converter and a controller that utilizes a spread spectrum strategy to reduce peak EMI values of the power control system. The controller generates a power regulation, switch control signal to control an input voltage to output voltage conversion by the switching power converter. The controller modulates the period of the control signal in accordance with the spread spectrum strategy. The spread spectrum strategy is an intentional plan to spread the spectrum of the control signal to reduce peak EMI values, and, thus, reduce the potential for degradation in performance, a malfunction, or failure of an electronic circuit caused by the EMI. The controller also modulates a pulse width of the switch control signal in response to modulation of the period of the control signal to provide power factor correction. | 10-07-2010 |
| 20100277072 | Calibration Of Lamps - In at least one embodiment, a lamp includes a controller configured to generate power control signals for a lamp is also configured to receive lamp calibration data received via one or more power terminals of the lamp. The controller is configured to process the calibration data to calibrate the lamp. In at least one embodiment, the lamp includes one or more light emitting diodes. | 11-04-2010 |
| 20100308742 | Power Control System for Current Regulated Light Sources - A light emitting diode (LED) lighting system includes a PFC and output voltage controller and a LED lighting power system. The controller advantageously operates from an auxiliary voltage less than a link voltage generated by the LED lighting power system. The common reference voltage allows all the components of lighting system to work together. A power factor correction switch and an LED drive current switch are coupled to the common reference node and have control node-to-common node, absolute voltage that allows the controller to control the conductivity of the switches. The LED lighting system can utilize feed forward control to concurrently modify power demand by the LED lighting power system and power demand of one or more LEDs. The LED lighting system can utilize a common current sense device to provide a common feedback signal to the controller representing current in at least two of the LEDs. | 12-09-2010 |
| 20100327765 | LOW ENERGY TRANSFER MODE FOR AUXILIARY POWER SUPPLY OPERATION IN A CASCADED SWITCHING POWER CONVERTER - A cascaded power converter having an auxiliary power supply operated from the second switching power stage provides efficient operation by activating the auxiliary power supply early in the startup process. A low energy transfer operating mode is initiated in the second switching power stage to charge the auxiliary power supply output without generating significant disruption at the load. After the first switching power stage is started and the intermediate node voltage has increased to a level sufficient to operate the second switching power stage, the final switching power stage enters a normal operating mode. The low energy transfer operating mode has a substantially reduced switching rate and pulse width from that of the normal operating mode. | 12-30-2010 |
| 20100327838 | SWITCHING POWER CONVERTER WITH CURRENT SENSING TRANSFORMER AUXILIARY POWER SUPPLY - A switching power converter having a current sensing transformer providing input to an auxiliary power supply provides efficient current sensing, while reducing the cost of the magnetic coupling element. The auxiliary power supply and current sense circuit both receive input from a secondary winding of a current sensing transformer having a primary winding coupled in series with the converter's main magnetic coupling element. To provide accurate sensing, the magnetization the current sensing transformer is accounted for. The magnetization is compensated for in the current sensing result, current sensing is performed during a part of the cycle in which charging of the auxiliary power supply is disabled, or the core of the current sensing transformer is made large, raising its mutual inductance. In another alternative technique, a circuit node can be pre-charged to a value that cancels the offset due to the magnetization current. | 12-30-2010 |
| 20100328976 | CASCODE CONFIGURED SWITCHING USING AT LEAST ONE LOW BREAKDOWN VOLTAGE INTERNAL, INTEGRATED CIRCUIT SWITCH TO CONTROL AT LEAST ONE HIGH BREAKDOWN VOLTAGE EXTERNAL SWITCH - An electronic system includes a low breakdown voltage (LBV) switch internal to an integrated circuit controller to control conductivity of an external, high breakdown voltage (HBV) switch. In at least one embodiment, the internal LBV switch and a cascode configuration of the LBV and HBV switches allow the controller to control the LBV switch and the HBV switch using an internal (“on-chip”) control signal. In at least one embodiment, the LBV switch and the cascode configuration of the HBV switch also allows the controller to control the LBV and HBV switches with more accuracy and less parasitic losses relative to directly controlling the HBV switch. Thus, in at least one embodiment, the low breakdown voltage switch is fabricated as part of an integrated circuit controller, and the high breakdown voltage switch is fabricated separately and located external to the integrated circuit controller. | 12-30-2010 |
| 20110016344 | AUDIO CLOCKING IN VIDEO APPLICATIONS - A method of operating an electronic video device such as a DVD player, wherein video clock signals and audio clock signals are derived from a system clock signal using two phase-lock loops, and these video and audio clock signals are used to process encoded video data and encoded audio data, but digital-to-analog conversion of the audio data stream is controlled by the system clock signal rather than the audio clock signals. By using the system clock signal to control the audio digital-to-analog converter (DAC), the DAC avoids the poor performance issues that can arise from jitter introduced into the audio clock signals by the PLL. The system clock signal may be divided by an integer to generate the sampling clock for the audio DAC. In the illustrative embodiment, the system clock signal has a rate which is not an integer multiple of the sample rate of the audio data stream. | 01-20-2011 |
| 20110032734 | CASCADED SWITCHING POWER CONVERTER FOR COUPLING A PHOTOVOLTAIC ENERGY SOURCE TO POWER MAINS - A cascaded switching power converter for coupling a photovoltaic (PV) energy source to power mains provides a high-efficiency and a potentially simple control mechanism for AC solar energy conversion systems. The PV energy source charges a capacitive storage element through a DC-DC converter, and an inverter couples energy from the capacitive storage element to the mains supply. The DC-DC converter is controlled so that ripple present on the capacitive storage element due to current drawn by the inverter is not reflected at the input of the DC-DC converter, which is accomplished by varying the conversion ratio of the DC-DC converter with the ripple voltage present across the capacitor. The average voltage of the capacitor can also be increased with increases in the available power output from the PV energy source, so that a corresponding increase in power is transferred to the mains supply. | 02-10-2011 |
| 20110050472 | DELTA-SIGMA ANALOG-TO-DIGITAL CONVERTER (ADC) HAVING A SERIALIZED QUANTIZER OUTPUT - A delta-sigma analog-to-digital converter (ADC) having a serialized quantizer output has a data rate greater than a quantization rate of the delta-sigma modulator, but less than a bit rate determined by the product of the number of bits required to represent the input to a feedback digital-to-analog converter and the quantization rate. Additional information can be encoded in the serial bit stream by selection among redundant codes based on the value of the additional information. The serial bit stream may encode differences between successive quantizer output samples and the additional information may include the absolute value of the quantizer output, synchronization information and/or framing information for distinguishing data corresponding to multiple ADC input channels. | 03-03-2011 |
| 20110075448 | SWITCHING POWER CONVERTER CONTROLLER WITH DIRECT CURRENT TRANSFORMER SENSING - A power control system includes a current transformer to step down a switch current of a switching power converter. In at least one embodiment, the stepped down current is received by a switching power converter controller. Since the current is received by the controller, the current is not converted into a voltage prior to receipt by the controller in order for the controller to monitor an inductor current of the switching power converter. In at least one embodiment, the controller compares the stepped down switch current with a reference current. In at least one embodiment, the controller includes a voltage converter to convert the switch current into a voltage within the controller. The controller compares the voltage representing the switch current with a reference voltage. The controller can use the current or voltage comparisons to control power factor correction and output voltage regulation of a switching power converter. | 03-31-2011 |
| 20110075723 | Thermal Feedback for Switch Mode Amplification - A thermal sensor at the output of a switching amplifier senses heat dissipation at the output switch. If an overheating condition is sensed, gain of the digital input signal is lowered to reduce output power of the audio output signal. | 03-31-2011 |
| 20110103111 | Switching Power Converter With Efficient Switching Control Signal Period Generation - A power control system includes a switching power converter and a controller, and the controller responds to a time-varying voltage source signal by generating a switch control signal having a period that varies in accordance with at least one of the following: (i) the period of the switch control signal trends inversely to estimated power delivered to a load coupled to the switching power converter, (ii) the period of the switch control signal trends inversely to instantaneous voltage levels of the voltage source signal, and (iii) the period of the switch control signal trends directly with a line voltage level of the time-varying voltage source signal. In at least one embodiment, the controller achieves an efficient correlation between the switching period with associated switching losses and the instantaneous power transferred to the switching power converter while providing power factor correction (PFC). | 05-05-2011 |
