Patent ID: 9112407
Filing Date: 2015-08-18
Classification: H02M,Y02B

Abstract:
1. A quasi-resonant device for a switching power comprising a transformer, a quasi-resonant module and a switching tube, comprising: a degaussing time sampling module, configured to sample a degaussing time T a valley sampling module, connected with the degaussing time sampling module, and configured to sample a resonant valley signal of the quasi-resonant module according to the feedback signal; a time producing module, connected with the degaussing time sampling module, and configured to produce a time T with a predetermined ratio D by processing the degaussing time T a logic processing module, connected with the valley sampling module and the time producing module respectively, and configured to obtain a first valley signal after the time T, wherein the first valley signal works as a switching signal T′ to turn on the switching tube.