Automatic water supply circuit is formed by 555 integrated chip

One-piece inductor

The circuit consists of a step-down rectifier circuit, a magnetron trigger and a relay control solenoid valve circuit, as shown in the figure.
HG is the reed switch magnetic control switch, normally in the off state, connected with it 555 and RP1, R2, C2, etc. to form a monostable delay circuit, the charging voltage on C2 (> 2 / 3 VDD) makes 555 In the reset state, relay K does not work. When the water is turned on and the magnetic card is placed in the input port, when the magnetic card passes the reed switch HG, the electric shock is instantaneously closed, the low level of the 555 pin 2 sets the 555, and the 3 feet turn to the high potential, the relay K is electrically attracted, its contact K1-1 is closed, and the solenoid valve DF is opened to release water.
The temporary stabilization time of the illustrated parameters, that is, the water discharge time after the bidding is about 5 seconds. Adjusting the RP1 can change the time of each water discharge. The short time may not be filled, and the long time may waste water.