Gate control circuit with capacitor for field controlled thyristor

摘要

The positive terminal of a series circuit consisting of two capacitors is connected with the cathode of a field controlled thyristor through a resistor and a transistor and the negative terminal thereof is connected with the gate of the field controlled thyristor. The junction of the series circuit is connected with the cathode of the field controlled thyristor through a thyristor. Each capacitor is charge by d.c. current. When the field controlled thyristor is intended to be turned off, the thyristor and the transistor are first made conductive and then the one capacitor is discharged through the thyristor. As a result, the field controlled thyristor is turned off. After the turn-off of the field controlled thyristor, the voltage of the other capacitor is applied to the gate of the field controlled thyristor to hold it in the blocking state.