A power factor correction circuit includes an input power source, a first bridge arm, a second bridge arm, an output capacitor and an active clamp unit. The first bridge arm includes a first switch and a second switch in series. The second bridge arm includes a third switch and a fourth switch in series. The active clamp unit includes a second inductor, a clamp capacitor and a fifth switch. The power factor correction circuit may realize the ZVS function of the first switch and the second switch by the collaboration of the active clamp unit and the conduction/non-conducting state of the first switch, the second switch, the third switch and the fourth switch.

An LED driver circuit and a method prevent LED turn-off flash when input power is lost to the driver circuit. The driver circuit includes a DC-DC converter that provides an LED drive voltage to an LED load. A voltage drop sensing circuit detects the loss of input power and discharges a filter capacitor that provides operating power to a controller in a DC-DC converter. The controller turns off to halt the operation of the DC-DC converter before the voltage provided to the LED load decreases to a turn-off threshold of the LED load. The DC-DC converter cannot recharge a load capacitor across the LED load. Thus, once the LEDs in the LED load turn off, the LEDs remain off until the input power is restored.

A boost rectifier that operates with a single-phase input voltage includes (i) an input stage receiving the single-phase input voltage and including first and second input filter capacitors, (ii) a switching converter stage coupled to the input stage and including a rectification circuit and an inductor circuit, series-connected first and second switches providing a common terminal therebetween, and a phase output capacitor, (iii) an output stage that transfers energy stored in the phase output capacitor to an output load, (iv) a decoupling stage that provides high-impedance decoupling between the switching converter stage and the output stage, and (v) a control circuit configured to operate the first and second switches according to an output signal of a non-linear compensation circuit that combines a feedforward signal derived from both the input and output voltages of the boost rectifier with an output voltage feedback control signal.

An integrated cinema amplifier comprises a power supply stage that distributes power over a plurality of channels for rendering immersive audio content in a surround sound listening environment. The amplifier automatically detects maximum and net power availability and requirements based on audio content by decoding audio metadata and dynamically adjusts gains to each channel or sets of channels based on content and operational/environmental conditions. A power supply stage provides power to drive a plurality of channels corresponding to speaker feeds to a plurality of speakers. The amplifier has a front panel having an LED array with each LED associated with a respective channel or group of channels of the multi-channel amplifier, and a control unit configured to light the LEDs according to display patterns based on operating status or error conditions of the amplifier.

A PFC converter and a control method thereof are provided. The PFC converter includes a first bridge, an inductor, a second bridge and a control unit. The first bridge includes a first switch and a second switch connected in series. There is a first node between the first and second switches. Two terminals of the inductor are coupled to the first node and a first terminal of an AC power source respectively. The second bridge includes a third switch and a fourth switch connected in series. There is a second node between the third and fourth switches, and the second node is coupled to a second terminal of the AC power source. The control unit controls a ratio of a high level duration on the second node in every line frequency cycle to be smaller than (250/Vbus).sup.2, where Vbus is an output voltage of the PFC converter.

The present disclosure relates to a power converter device including a power factor correction circuit, a resonance converter circuit, and a zero voltage switching circuit. The power factor correction circuit is coupled to the primary side rectifier circuit, and includes a first switching circuit, a first control circuit and a first output circuit. The resonance converter circuit includes a second switching circuit and a second control circuit. The second switching circuit is coupled to the first output circuit, and the second control circuit is coupled to the secondary side rectifier circuit. The zero voltage switching circuit is coupled between the first control circuit and the second control circuit. The zero voltage switching circuit is configured to obtain a switching voltage of a switch element in the second switching circuit, and output an adjustment signal to the first control circuit according to the switching voltage.

A power supply apparatus includes a switching circuit including a switcher, a first input terminal, a second input terminal, and an output terminal, the first input terminal is configured to receive a first voltage provided by a first power supply, the second input terminal is configured to receive a second voltage provided by a second power supply, and the switcher is configured to control the output terminal to be connected to the first input terminal or control the output terminal to be connected to the second input terminal; and a converting circuit including an input terminal connected to the output terminal of the switching circuit, an output terminal connected to an electrical device, and the converting circuit is configured to receive the first or the second voltage, convert the received first second voltage into a third voltage, and output the third voltage through the output terminal of the converting circuit.

An isolated, power factor corrected, converter, for operation from a three-phase AC source, comprises three power processors, each power processor connected to one of the three phases. Each power processor comprises a cascade of a first and a second power conversion stage. At least one of the first and second power converters in each power processor is configured to provide galvanic isolation through a DC Transformer between the power processor input and output. At least one of the first and second power converters in each power processor is configured to provide power factor correction at the AC source. Substantially all of the bulk energy storage and low frequency filtering is provided by storage elements at the output of the power system. Low voltage semiconductor devices may be cascaded to implement low output capacitance high voltage switches in a multi-cell resonant converter for high voltage applications.

A single phase single stage level-1 electric vehicle (EV) battery charger can control the power flow in both directions. The converter efficiency is high as the devices undergo ZCS which reduces switching loss in the devices. This converter does not require any intermediate DC link capacitor stage and the power density of the converter is high.

A switched-mode AC-DC converter intended to deliver a DC output voltage V.sub.out between a first output terminal and a second output terminal, the converter comprising at least one conversion chain intended to convert an AC input voltage applied between an input terminal and a neutral point, the conversion chain comprising: a first output capacitor comprising one terminal connected to the first output terminal and another terminal connected to a second terminal of the input switch, a second output capacitor with the same capacitance as the first output capacitor and with a higher capacitance than the capacitance of the link capacitor, the second output capacitor comprising one terminal connected to the second output terminal and another terminal connected to the second terminal of the input switch.