Abstract: The method, apparatus and system of a single-stage current-fed clamped series resonant power factor corrected (PFC) converter CF-CSRC provides power conversion and current regulation. The CF-CSRC system may be implemented in a single-stage isolated topology for high efficiency unity power factor correction (PFC) converter applications. Moreover, the CF-CSRC system combines the intrinsic advantages of the classical clamped series resonant converter while mitigating drawbacks by using an integrated boost input current shaper.

Abstract: The method, apparatus and system of a single-stage current-fed clamped series resonant power factor corrected (PFC) converter CF-CSRC provides power conversion and current regulation. The CF-CSRC system may be implemented in a single-stage isolated topology for high efficiency unity power factor correction (PFC) converter applications. Moreover, the CF-CSRC system combines the intrinsic advantages of the classical clamped series resonant converter while mitigating drawbacks by using an integrated boost input current shaper.

Abstract: Provided is a backup power system for providing power to a load when a primary lighting system is disabled. The backup power system includes an energy source configured to supply an amount of power to the backup power system, and a charger connectable to the energy source and a power source of the primary lighting system. The backup power system additionally includes a controller configured to measure a current value of the primary lighting system and determine a backup current value corresponding to an amount of backup current that is a fractional amount of the determined current value. The backup power system include a current source configured to provide the determined backup current.

Abstract: A resonant converter includes a primary stage having first and second switches coupled in series, a controller coupled to the first switch and the second switch to control operation thereof, a first transformer comprising a primary coil coupled to a node between the first and second switches, and a resonant inductor coupled to the primary coil of the first transformer. The resonant converter also includes a secondary stage having a second transformer formed of a primary coil coupled to the resonant inductor and a secondary coil comprising first and second coil sections, a third switch coupled to the first coil section of the secondary coil, and a fourth switch coupled to the second coil section of the secondary coil. A switch drive circuit is provided to drive the third and fourth switches for synchronous rectification, with the switch drive circuit comprising a secondary coil of the first transformer.

Abstract: A universal power adapter includes a power converter configured to generate an output power based on a switching frequency of the power converter. The universal power adapter also includes a frequency controller operatively coupled to the power converter and configured to control the switching frequency of the power converter. The universal power adapter further includes a switch capacitor circuit having a plurality of capacitive elements, operatively coupled to the power converter. The switch capacitor circuit is configured to switch between the plurality of capacitive elements. The universal power adapter also includes a capacitance controller operatively coupled to the switch capacitor circuit and configured to control the switch capacitor circuit to control switching between the plurality of capacitive elements to maintain a control parameter within a threshold range of.

Abstract: The method, apparatus and system of a single-stage current-fed clamped series resonant power factor corrected (PFC) converter CF-CSRC provides power conversion and current regulation. The CF-CSRC system may be implemented in a single-stage isolated topology for high efficiency unity power factor correction (PFC) converter applications. Moreover, the CF-CSRC system combines the intrinsic advantages of the classical clamped series resonant converter while mitigating drawbacks by using an integrated boost input current shaper.

Abstract: There are provided a driver circuit, a method of driving a power switch, and a ballast circuit. For example, there is provided a driver circuit configured to receive a control signal and operate a power switch. The driver circuit includes a first switch, a second switch, and a capacitor coupled to control terminals of the first and second switches. The driver circuit further includes a first diode coupled to a first bias terminal of the driver circuit and to the capacitor. Furthermore, the driver circuit includes a second diode coupled to a second bias terminal of the driver circuit and to a terminal of the power switch.

Abstract: An electronic device includes a controller configured to regulate one or more voltages or currents of a power converter. The controller is configured to receive an input voltage of the power converter, determine whether the power converter is operating in a first mode of operation or a second mode of operation based at least in part on the input voltage, generate a multiplier reference signal for the power converter based on whether the power converter is operating in the first mode of operation or the second mode of operation, and adjust an input current of the power converter based at least in part on the multiplier reference signal. Adjusting the input current includes correcting the input current to be substantially identical in form to the input voltage.

Abstract: An electronic device includes a controller configured to regulate one or more voltages or currents of a power converter. The controller is configured to receive an input voltage of the power converter, determine whether the power converter is operating in a first mode of operation or a second mode of operation based at least in part on the input voltage, generate a multiplier reference signal for the power converter based on whether the power converter is operating in the first mode of operation or the second mode of operation, and adjust an input current of the power converter based at least in part on the multiplier reference signal. Adjusting the input current includes correcting the input current to be substantially identical in form to the input voltage.

Abstract: There are provided a driver circuit, a method of driving a power switch, and a ballast circuit. For example, there is provided a driver circuit configured to receive a control signal and operate a power switch. The driver circuit includes a first switch, a second switch, and a capacitor coupled to control terminals of the first and second switches. The driver circuit further includes a first diode coupled to a first bias terminal of the driver circuit and to the capacitor. Furthermore, the driver circuit includes a second diode coupled to a second bias terminal of the driver circuit and to a terminal of the power switch.

Abstract: Provided is a backup power system for providing power to a load when a primary lighting system is disabled. The backup power system includes an energy source configured to supply an amount of power to the backup power system, and a charger connectable to the energy source and a power source of the primary lighting system. The backup power system additionally includes a controller configured to measure a current value of the primary lighting system and determine a backup current value corresponding to an amount of backup current that is a fractional amount of the determined current value. The backup power system include a current source configured to provide the determined backup current.

Abstract: A universal power adapter includes a power converter configured to generate an output power based on a switching frequency of the power converter. The universal power adapter also includes a frequency controller operatively coupled to the power converter and configured to control the switching frequency of the power converter. The universal power adapter further includes a switch capacitor circuit having a plurality of capacitive elements, operatively coupled to the power converter. The switch capacitor circuit is configured to switch between the plurality of capacitive elements. The universal power adapter also includes a capacitance controller operatively coupled to the switch capacitor circuit and configured to control the switch capacitor circuit to control switching between the plurality of capacitive elements to maintain a control parameter within a threshold range of.

Abstract: A resonant converter includes a primary stage having first and second switches coupled in series, a controller coupled to the first switch and the second switch to control operation thereof, a first transformer comprising a primary coil coupled to a node between the first and second switches, and a resonant inductor coupled to the primary coil of the first transformer. The resonant converter also includes a secondary stage having a second transformer formed of a primary coil coupled to the resonant inductor and a secondary coil comprising first and second coil sections, a third switch coupled to the first coil section of the secondary coil, and a fourth switch coupled to the second coil section of the secondary coil. A switch drive circuit is provided to drive the third and fourth switches for synchronous rectification, with the switch drive circuit comprising a secondary coil of the first transformer.

Abstract: A two-stage light emitting diode (LED) driver for powering an LED load at a substantially constant current, and related methods and systems. The first or front end stage of the LED driver includes a buck topology power factor correction (PFC) circuit, the buck PFC circuit and a PFC controller. The second stage of the LED driver includes a conventional isolation and regulator circuit configured to receive the DC voltage and DC current output by the buck PFC and then to provide the substantially constant current to the LED load. By multiplying the rectified input voltage sensed by the PFC controller, the input AC current drawn by the buck PFC circuit has a much improved total harmonic distortion (THD), which is achievable without the need for using an expensive PFC controller. The rectified input voltage is multiplied using a Zener diode ladder.

Abstract: A power harvesting circuit includes a first switch connected in series between an AC source and a load, a switch control circuit connected to the switch and operable to cause the switch to cycle AC power to the load, and a power collection circuit for collecting power resulting from the power cycling. A method of power harvesting includes cycling AC power to a load using a switch, and collecting power generated by the power cycling and providing the collected power for use by a load control circuit. An active controller includes a load control circuit, and a power harvesting circuit having first switch connected in series between an AC source and a load, a switch control circuit connected to the switch and operable to cause the switch to cycle AC power to the load, and a power collection circuit for collecting power resulting from the power cycling.

Abstract: A single-stage AC-DC power converter for powering a load at a substantially constant current, and related methods and systems. The AC-DC power converter includes a high power factor correction (PFC) circuit configured in a flyback topology and operating in transition mode. The flyback PFC circuit outputs a direct current (DC) voltage and a DC current. The PFC circuit further includes a flyback transformer and a switch circuit that selectably toggles the substantially constant output current provided to the load between a first and a second, preset constant current. The secondary windings of the flyback transformer are split into two sections, and the switch circuit toggles the two sections of the secondary windings between a series and a parallel configuration to provide the first and second, preset constant currents. The switch circuit includes a switch and three, fast Schottky diodes.

Abstract: A two-stage AC-DC power converter for powering a load at a substantially constant current, and related methods and systems. The first stage of the AC-DC power converter includes a conventional power factor correction (PFC) circuit that outputs a direct current (DC) voltage and a DC current. The second stage of the AC-DC power converter includes a low voltage flyback circuit that receives the DC voltage and the DC current. The low voltage flyback circuit includes a flyback transformer and a switch circuit that selectably toggles the substantially constant output current provided by the low voltage flyback circuit to the load between a first and a second, preset constant current. The secondary windings of the flyback transformer are split into two sections, and the switch circuit toggles the two sections of the secondary windings between a series and a parallel configuration to provide the first and second, preset constant currents.

Abstract: A two-stage LED driver for providing a substantially constant output current to an LED load, and related methods and systems. The first stage of the LED driver includes a conventional power factor correction (PFC) circuit that outputs a direct current (DC) voltage and a DC current. The second stage of the LED driver includes a low voltage flyback circuit that receives the DC voltage and the DC current. The low voltage flyback circuit includes a flyback transformer and a switch circuit that selectably toggles the substantially constant output current provided by the low voltage flyback circuit to the LED load between a first and a second, preset constant current. The secondary windings of the flyback transformer are split into two sections, and the switch circuit toggles the two sections of the secondary windings between a series and a parallel configuration to provide the first and second, preset constant currents.

Abstract: A single-stage AC-DC power converter for powering a load at a substantially constant current, and related methods and systems. The AC-DC power converter includes a high power factor correction (PFC) circuit configured in a flyback topology and operating in transition mode. The flyback PFC circuit has a PFC controller and is configured to draw an input AC current from an AC power supply. The input AC current has a first total harmonic distortion (THD). The flyback PFC circuit outputs a DC current to the load. The PFC controller is configured to sense a rectified input voltage. By multiplying the rectified input voltage sensed by the PFC controller, the input AC current drawn by the flyback PFC circuit has a second, much improved THD, which is achievable without the need of an expensive PFC controller. The rectified input voltage sensed by the PFC controller is multiplied using a Zener diode ladder.

Abstract: A single-stage AC-DC power converter for powering a load at a substantially constant current, and related methods and systems. The AC-DC power converter includes a high power factor correction (PFC) circuit configured in a flyback topology and operating in transition mode. The flyback PFC circuit outputs a direct current (DC) voltage and a DC current. The PFC circuit further includes a flyback transformer and a switch circuit that selectably toggles the substantially constant output current provided to the load between a first and a second, preset constant current. The secondary windings of the flyback transformer are split into two sections, and the switch circuit toggles the two sections of the secondary windings between a series and a parallel configuration to provide the first and second, preset constant currents. The switch circuit includes a switch and three, fast Schottky diodes.