| 摘要 |
PURPOSE:To increase dV/dt withstand voltage without increasing the minimum luminous energy of trigger by a method wherein the displacement current generated at the lower part of an auxiliary emitter is branched off by the switching element which is controlled and driven by the displacement current generated at the circumferential part of the optical trigger thyristor. CONSTITUTION:A light-receiving section 1 is formed by exposing a P-base 5 at the center part of the auxiliary emitter 2, and an annular electrode 11 is provided on the circumference of the light-receiving section 1. The annular electrode 11 and a cathode electrode 10 are connected through the intermediary of a transistor Q. A groove 13 is provided on the circumference of the main emitter 3 by performing an etching and the like, and a high resistance layer R3 is formed. On the P-base layer 5 of the outer circumferential section, an annular electrode 12 made of aluminum is provided, and it is connected to the base terminal B of the transistor Q. When a positive voltage of a quick rising speed is applied, most of the displacement current generated at the outer circumference of the annular electrode 12 runs to a cathode K passing through the base of the transistor Q, the transistor Q is turned ON, and the displacement current at the light-receiving section is branched off. |
