| 摘要 |
PURPOSE:To reduce the duty of a pulse transformer for supplying a trigger signal, by connecting a resistance in parallel to a transistor by which obtaines a gate current for turning off a GTO and by flowing the gate current after turn- off through this resistance. CONSTITUTION:A turn-on gate circuit 2 and a turn-off gate circuit 3 are connected to a GTO1. A trigger signal VP2 is supplied from a pulse transformer to a transistor TR21 of the turn-on gate circuit 2. A resistance 5 for by-pass is connected in parallel between the collector and the emitter of a TR31 of the turn-off gate circuit 3. A trigger signal VP3 is given from the pulse transformer to the base of the TR31. When the trigger signal VP3 is applied, the TR31 becomes conductive, and a capacitor 32 is discharged to turn off the GTO1. The conduction time of the TR31 is the turn-off time, and a current from a power source 33 is flowed to the resistance 5 in the reverse bias time to reduce the duty of the pulse transformer. |
