| 摘要 |
PURPOSE:To shorten the response time, by selecting the conditions for detection of power supply voltage of a sensor circuit which flows the gate current of a thyristor at a level lower than the supply voltage of a constant voltage circuit. CONSTITUTION:The detecting voltage of a voltage detecting circuit of a sensor circuit 1 containing in series a Zener diode is set at a level lower than the output voltage of a constant voltage circuit consisting of a transistor TR5, a resistance 6 and a Zener diode 7. When the circuit 1 connected with a coil 2 is turned off, a TR8 is turned off. A thyristor 9 has no supply of gate current and is turned off. When the circuit 1 is turned on, the TR8 is also turned on. Then the thyristor 9 is turned on. The thyristor 9 is turned off with each negative half wave of AC current but turned on again by the function of a capacitor 3 and when the voltage of the positive half wave has a rise. Thus the power is supplied to a load 17. |
