| 摘要 |
PURPOSE:To obtain a low-cost gate circuit of gate turn-off thyristor GTO by installing the off-driving SCR, the auxiliary SCR to give inversion to the reverse charging voltage of the off-capacitor and the reverse current blocking diode each to the off- gate circuit. CONSTITUTION:Capacitor COFF is charged up to voltage VN by power source N, and the GTO is turned on with application of pulse signal ON. If gate pulse igsoff is suplied under these conditions, SCRSOFF is turned on to flow current igof of the turn-off gate circuit and thus to turn off the GTO. When the discharge current of COFF is extinguished, COFF is reversely charged up to VR by the lead inductance component of the GTO. During this time, gate pulse igsw is applied to turn on auxiliary SCRSW, and SCRSOFF is reversely biased by the reverse current of the reverse charge voltage of COFF to turn off it. In this case, the discharging toward the gate of GTO is prevented by diode D. Thus COFF is charged again up to VN. As a result, the GTO gate circuit can be formed with the low-cost and high-reliability component parts. |
