Patent ID: 6404654
Filing Date: 2002-06-11
Classification: H02M,Y02B

Abstract:
Self-oscillation type resonant flyback converter comprising:a series combination of a primary winding and a switching transistor; a secondary winding is connected to a power diode and to an output capacitor; a feedback winding is connected to a delay driving circuit that comprises a delay diode, a constant-current diode and a capacitor; said delay driving circuit is provided to delay a positive feedback signal from said feedback winding, so that when said power diode becomes non-conducting, said delay diode becomes in the reverse conduction state, starting a free resonance period that concludes when the said delay diode becomes non-conducting; a snubber capacitor connected in parallel with said switching transistor; and reverse recovery current in said power diode being effective to discharge an electric charge of said snubber capacitor.