| 摘要 |
PURPOSE:To omit a large and expensive insulating transformer and to improve reliability such as noise resistance by obtaining a power source from a snubber circuit provided for a GTO thyrister in the gate driving circuit of a gate turn-off(GTO) thyrister. CONSTITUTION:A second capacitor 30 is charged from a snubber capacitor 22 to constitute a snubber circuit through an impedance element 32 and a thyrister 34. The thyrister 34, when an ON command signal is inputted to a monostable 44 simultaneously with a gate driving unit 12 of a GTO thyrister 10, the signal waveform-shaped to a prescribed pulse width is outputted from the monostable 44, the output signal is inputted as the gate pulse of the thyrister 34, the thyrister 34 is ignited and the second capacitor 30 is charged. Thus, the charging voltage per one time of the second capacitor 30 can be made smaller than the element voltage of the GTO thyrister 10. |
