Patent ID: 7817448

Claim:
A power supply system for reducing reverse current, the system comprising: at least one primary side circuit, coupled to at least one alternating current power source, for receiving alternating current power; at least one transformer circuit, coupled to said at least one primary side circuit, for transforming voltage; at least one secondary side rectifier circuit, coupled to said at least one transformer circuit, for rectifying voltage; at least one secondary side filter circuit, coupled to said at least one secondary side rectifier circuit, for filtering voltage and providing power to at least one device; at least one first voltage division circuit, coupled between said at least one secondary rectifier circuit and said at least one device, for providing at least one first voltage division signal; at least one switch circuit, coupled to said at least one first voltage division circuit, for comparing said at least one first voltage division signal with at least one reference voltage signal and deciding conducting conditions of said at least one switch circuit; at least one second voltage division circuit, coupled between said at least one transformer circuit and said at least one secondary rectifier circuit, for providing at least one second voltage division signal; and at least one control circuit, coupled to said at least one second voltage division circuit, said at least one switch circuit, and between said at least one primary side circuit and said at least one transformer circuit, for receiving said at least one second voltage division signal and deciding whether to charge said at least one device or not based on said at least one second voltage division signal when said at least one switch circuit is conducted; wherein said at least one second voltage division circuit comprising at least one rectifier component and at least one filter component.