Response Time of Thyristors: Theoretical Study and Application to Electronic Switching Networks

After restating the experimental definition of the response time of a low-power thyristor by assuming a well-defined dc triggering current, the authors show that the equivalent two-transistor representation of the thyristor leads to a theoretical interpretation of the triggering condition under certain simplifying assumptions. The accuracy of this theoretical model is shown to be satisfactory. A practical definition of the response time of a thyristor is proposed, and the literal expression of the response time as a function of the parameters of both constituent transistors is given. Examples of application are then given in the design of the switching networks of the IBM 2750, where thousands of thyristors are used as crosspoints arranged in matrices and connected in series.