| 摘要 |
PURPOSE:To reduce the turning OFF switching loss of a switching transistor of the primary side by effectively turning OFF a switching transistor of the secondary side and then turning OFF the switching transistor of the primary side. CONSTITUTION:A pulse width modulation signal as the output of a pulse width modulator 14 is inputted to one input terminal of an OR gate 19 through a delay circuit 18. A pulse width modulation signal of the pulse width modulator 14 is inputted directly to the other input terminal of the gate 19. The output of the gate 19 is supplied to a driver 16. The turning ON time of the switching transistor 2 of the primary side of a converter transformer 1 is prolonged by the delay circuit 18 for the prescribed period, thereby effectively turning OFF the transistor 2 after a switching transistor 5 of the secondary side of the transformer 1 is reliably turned OFF. |
