GATE-TURNOFF THYRISTOR (GTO).

Abstract

Semiconductor switches are used for the low-loss control of drives of all descriptions, and for power levels above 10kW preference is given to thyristors. Hitherto it has been the practice for thyristors to be turned off by means of an external auxiliary thyristor that conducts the load current for a short time interval past the main thyristor. In the GTO this function is integrated on one chip. The design of the cathode and the gate electrode largely determines the switching speed and the required turnoff power. Future technological advances, especially adaption to IC technology, can be expected to open the way to significant improvements in controllability and dynamic performance.