| 摘要 |
PURPOSE:To enable the prevention of malfunction due to the variation in various kinds of conditions by a method wherein the time constant of a transistor formed by adjacent three layers in a thyristor is so set as to come into the range of a specific condition. CONSTITUTION:The transistor TR21 is provided between the gate G and the cathode K of the thyristor, and a TR30 is connected between the base of the TR 21 and the n-base 12 of the thyristor. When the time constant of the TR20 formed of the p1n1p2 layer of the thyristor is tau1, and the time constant of the TR30 is tau2, the value of tau2/tau1 is so set as to be in the range of 0.1-0.5. The selection of the value of the time constant ratio tau2/tau1 in this range enables the formation of a semiconductor switch execellent in noise resistance. With the value of tau2/tau1 of 0.1 or less, a practical element can not be formed because of low dv/dt strength. With the value of 0.5 or more, ignition does not occur even when ignition pulses are impressed. The selection of the value in the range of 0.1-0.5 is enabled by putting each pattern of the p1n1p2 TR20 and TR30 of the thyristor in congruency or similarity. |
