Simple intelligent flushing water saving device based on 555

Probe domestic double-head probe 038-BB-5.7L The shape of the two ends of the needle is outside the pointed needle

As shown, the flushing device includes a buck rectifier circuit, a monostable timing circuit, and a switch control portion.
In this circuit, K is the urinal clamp switch. When the person leaves the clamp plate, K1 is turned on, K2 is turned off, and 2 feet are momentarily low level, 555 is set, 3 feet is high level, and C2 is charged. When the potential of pin 1 of IC2 is greater than the open threshold level of TWH8751 switch tube D2, IC2 is turned on, J is pulled, the normally open contact J1-1 is closed, and the electromagnetic water valve DF is turned on and discharged.