| 摘要 |
PURPOSE:To obtain a control circuit which does not erroneously operate for a noise by normally applying a very small counterelectromotive force, setting a gate voltage as no voltage for the prescribed time after an input signal is turned OFF, and then applying a reverse voltage for OFF of a thyristor. CONSTITUTION:A thyristor 18 is controlled to be driven by a control signal from an ON-OFF control signal terminal. This control circuit has an ON signal control circuit having a pulse transformer 10 connected in series with a full-up resistor 9 through a NOT circuit 8. Further, an OFF signal control circuit which has a timer 11 including T1/T2, a transistor 15, NOT circuits 12, 12, and a pulse transformer 17 is used. The outputs of the transformers 10, 17 are subtracted to be connected to the gate of a thyristor 18. Thus, the gate voltage of the thyristor 18 becomes no voltage only for the prescribed time T1 by the fall of the ON signal of the control signal, and the reverse voltage that the thyristor 18 is initially turned OFF after the T1 is applied for the time T2. |
