| 摘要 |
PURPOSE:To simplify a circuit by insulating the applied voltage of thyristors at a guide line, and loading the insulation in the thyristors connected in series in a pulse transformer, thereby reducing the number of parts. CONSTITUTION:A series unit of thyristors 10A, 10B having snubber resistors 11A, 11B, snubber capacitors 12A, 12B is fired through a pulse amplifier, a firing signal converted by an electro/optical converter 17 fed through a light guide 18 to a high voltage side firing unit 2, converted into an electric signal 21, and then pulse transformers 25A, 25B. With the connecting point of the thyristors 10A, 10B as a reference voltage a voltage between an anode and a cathode is detected by detectors 26A, 26B, input to AND gates 22A, 22B to be opened or closed. Thus, the light guide 18 insulates the voltage applied to the thyristor 10 and the ground potential, and the transformer 25 merely insulates the voltage shared by the thyristor 10 to be reduce in size. |
