Patent ID: 7532489

Claim:
A power factor correction (PFC) power supply, comprising: a bridge rectifier having an input and an output; a filter capacitor connected to the output of the bridge rectifier; a transformer having a primary winding, a fly-back winding and a secondary winding; a forward diode; a fly-back diode; a storage capacitor circuit having a valley-fill circuit and a capacitor connected in parallel; and a switch connected between the primary winding and the output of the bridge rectifier; wherein an anode of the forward diode is connected to a positive output of the bridge rectifier, and a cathode thereof is connected to a first end of the storage capacitor circuit and the primary winding; an anode of the fly-back diode is connected to the positive output of the bridge rectifier, and a cathode thereof is connected to a first end of the fly-back winding; a second end of the fly-back winding is connected to the first end of the storage capacitor circuit and the primary winding; a first end of the storage capacitor circuit is connected to the first end of the primary winding, and a second end thereof is connected to a negative output of the bridge rectifier; and a first end of the switch is connected to the second end of the primary winding, and a second end thereof is connected to the negative output of the bridge rectifier.