Thyristor firing circuit module with integral optical isolation, dv/dt limitation, and bidirectional voltage transient suppression

摘要

A thyristor firing module for use in high power circuits which provides protection against damage or misfiring. The module comprises optically isolated control circuitry optically coupled to firing circuitry which in turn is coupled to a darlington transistor pair to produce a high current drive pulse to fire the thyristor. The module also includes varistor control of voltage across the thyristor. Power for the firing circuitry is derived from the voltage across the thyristor in its non-conducting state.