| 摘要 |
A switching power source apparatus has a switching element Q 1 . Between terminals of the switching element Q 1 , there is parasitic capacitance (C 1 , C 2 ). A voltage V 4 of parasitic oscillation appears at a gate of the switching element Q 1 after a flyback period. A voltage detector detects a drop in the voltage V 4 and outputs a detection signal V 6 . The detection signal V 6 is delayed by a timer, which outputs an ON start signal synchronized with timing T at which the voltage V 4 reaches a bottom level. In response to the ON start signal from the timer, a controller outputs an ON control signal to turn on the switching element Q 1 . In response to the ON control signal from the controller, a driver applies a drive signal to the gate of the switching element Q 1 , thereby driving the switching element Q 1.
|
