Patent ID: 6295213
Filing Date: 2001-09-25
Classification: H02M,Y02B

Abstract:
In a power converter coupled to an input voltage source for supplying power to an output load, said converter having a first transformer including a first primary winding and a first secondary winding, said first secondary winding coupled to an output rectifier circuit whose output is coupled to said output load, a primary switch connected to said first primary winding, and a control circuit for controlling the switching of said primary switch, a reset voltage circuit for recycling the magnetization energy in said first transformer back to said input voltage source and for providing a source of auxiliary power, comprising:a clamp diode;a clamp capacitor in series with said clamp diode and coupled between said input voltage source and said primary switch for clamping the reset voltage across the primary switch when said primary switch turns off and for storing the reset energy generated thereby;an auxiliary converter having a first switch, a second switch, and a second transformer including an auxiliary primary winding and an auxiliary secondary winding, said auxiliary primary winding coupled between said first and second switches, said auxiliary primary winding also coupled to said clamp capacitor, said first and second switches operating to couple the stored energy in said clamp capacitor to said input voltage source; andan auxiliary power generator coupled to said auxiliary secondary winding for generating said auxiliary power.