| 摘要 |
PURPOSE:To charge each capacitor momentarily and to flow a normal ON high gate current at the high frequency switching operation by charging a 1st capacitor and a 2nd capacitor for ON high gate current while using one terminal of the capacitors as a negative potential. CONSTITUTION:A 1st switch 19 and a 2nd switch 20 are provided respectively to a common part of the 1st capacitor 8 and the 2nd capacitor 9, the 1st switch 19 is connected to zero potential and the 2nd switch 20 is connected to a negative potential. In turning off the ON gate switch 12 and turning on the OFF gate circuit 13, a negative OFF gate current is fed to a GTO 1. Simultaneously, the 1st switch 19 is turned off and the 2nd switch 20 is turned on to bring the common part of the 1st and 2nd capacitors 8, 9 to a negative potential, and the 1st capacitor 8 through the 3rd charging diode 18 and the 1st charging diode 6, and the 2nd capacitor 9 through the 4th charging diode 17 are charged momentarily up to the ON gate power voltage respectively. |
