Patent ID: 6747421
Filing Date: 2004-06-08
Classification: H02M,H05B,Y02B

Abstract:
A self oscillation circuit for converting DC power to AC power said self oscillation circuit comprising:an output transformer having a primary side and a secondary side, wherein the secondary side is adapted to have a load connected thereto; an LC primary side resonance circuit formed at the primary side of the output transformer; a switching circuit operable to turn on and off the DC power, the switching circuit having a drive circuit operable to turn the switching circuit on and off based on a feedback signal of a primary side resonance voltage induced in the LC primary side resonance circuit and convert the DC power to the AC power to drive the output transformer, a phase detecting device operable to detect a phase signal of a resonance wave form at the primary side of the output transformer as the feedback signal and output the phase signal, and a control circuit operable to output a drive signal that controls the on-off of the switching circuit based on the phase signal; and a start compensating circuit operable to detect a current flowing to the load and supply a start signal for self oscillation to the control circuit before the current flows to the load at a time of conversion of the DC power to the AC power.