| 摘要 |
PURPOSE:To materialize the high output and the downsizing of a circuit by turning off a switching element at high speed. CONSTITUTION:In a power circuit, which uses a switching element FET 1 generating a specified current from a power source via a transformer T1, the driving winding L3 of the transformer T1, a resistor R19, and a capacitor C11 are connected in series to the control terminal of a switching element FET so as to drive this switching FED And, it is equipped with a detection resistor R17, which detects the current flowing through switching element FET, transistors Q11 and Q12 for control, which turns off the switching element FET, according to the voltage of the detection resistance R17, a capacitor C12, which generates negative voltage by the induced voltage of the driving winding L3 during the OFF period of the switching element FET a transistor Q13, which controls the quantity of charge of this capacitor C12, and a photocoupler PC. |
