High-reliability general-purpose timer (CC4518, CC4001)

As shown in the figure, this is a high-reliability universal timing circuit. The timing time of this circuit can be from 0.1 minutes to 99.9 minutes. The timing mode is BCD counting. The control state can make the socket CZ power on or off at a time. IC2 and IC3 are cascaded BCD counters/distributors, K1~K3 are BCD decoding dial timing selection switches, IC1 is RS trigger and timing time base oscillator, and AN is the timing control state selection. When the DC power supply is turned on, the circuit is automatically reset, the timing time starts, and the relay J works according to the AN preset state. If the timing time is up, A1~A3 output high level, the R-S trigger changes state, J also changes state, the oscillator stops oscillating, the LED goes out, and the timing time ends.