Dual meter controlled thyristor timer circuit (3)

This timer is controlled by two electronic watches with alarm output through a thyristor. It can be turned on/off at will. After shutting down, it cuts off the power from the primary side of the power transformer. It has no waste, is safe, saves electricity and has high reliability. Working principle: The circuit is as shown in the attached picture. When using, press K1, and the power supply will get 6V DC after being stepped down, rectified and filtered by B, D1 and C1. At this time, the normally closed contact J-3 of the power supply causes J1 to work, the normally open contact J1-1 of J1 is closed, and the circuit is self-locking. At this time, after releasing K1, the circuit is in working state due to self-locking. When the scheduled power-on audio signal is input from both terminals A and B, it is rectified and filtered by D3 and C3 and triggers the thyristor SCR1, so that J2 is powered to work, the normally open contact J-2 of J2 is closed, and the socket W is powered and controlled Electrical appliances are switched on. In the same way, when the scheduled shutdown audio signal of another electronic alarm clock enters from C and D, it is rectified and filtered by D5 and C4 and triggers SCR2. J3 is powered to work, and the normally closed contact J-3 of J3 is released and disconnected. J1 loses power, causing the normally open contact J-1 of J1 to also release and disconnect, and the entire circuit stops working. R1 is the current limiting resistor, C2 is the starting capacitor of J1, and D2, D4, and D6 are protection diodes. Production: B uses a small 12V transformer, and the output current should be greater than the sum of the working currents of J1, J2, and J3. J1, J2, and J3 can be used with 6V small single-pole relays. The contact current of J2 can be determined according to the power of the controlled electrical appliance. A few tens of milliamperes can be used for the thyristor.