Abstract: A single-stage power factor correction circuit includes a first rectifier, a second rectifier, a full bridge rectifier, a capacitor, a fly back transformer, and a switch. Unlike conventional single-stage power factor correction circuits, the present invention just needs to pass through two rectifiers at positive and negative half cycles, so as to reduce the conduction loss, lower the temperature of the power supply, and control the voltage of the control energy storage capacitor, and stabilize voltage output.

Abstract: An active clamp switching circuit includes a transformer having a primary winding and a secondary winding, a first switch, a capacitor, an impedance device, a second switch and a rectifier. The capacitor, the impedance device and the second switch form a reset loop for the primary winding so that the impedance device lowers the electric current going through the second switch, preventing burnout of the second switch.

Abstract: A single-stage power factor correction circuit includes a first rectifier, a second rectifier, a full bridge rectifier, a capacitor, a fly back transformer, and a switch. Unlike conventional single-stage power factor correction circuits, the present invention just needs to pass through two rectifiers at positive and negative half cycles, so as to reduce the conduction loss, lower the temperature of the power supply, and control the voltage of the control energy storage capacitor, and stabilize voltage output.

Abstract: A soft-switching circuit for a power supply comprises a bridgeless rectifier circuit and an auxiliary circuit. The auxiliary circuit is connected to the bridgeless rectifier circuit, which comprises at least one filtering inductor, two main switches, two diodes and a capacitor. The filtering inductor is connected to the first diode. The first diode is connected to the second diode. The second diode is connected to the first main switch. The first main switch is connected to the second main switch. The diodes and the main switches are connected in parallel with the capacitor to reduce conducting loss. The auxiliary circuit comprises at least one resonant inductor, an auxiliary switch, at least two diodes and a voltage source circuit. The diodes are connected to the resonant inductor and further connected to the voltage source circuit.