Pulse water level controller circuit

Circuit working principle: power transformer T, VD. A VD. and C. Makes up
the 12 V power supply circuit for the entire device. A, y, and C are the three detection electrodes in the pool. Ic, and
IC 2 are two 555 time base integrated circuits. Among them, Ic, R, R2 and cz form a multivibrator
. Its pin 3 outputs a low voltage with a pulse width of only about 0 1 s every 50 s.
flat pulse . IC 2, R4, and C3 form a monostable trigger with a delay of about 70 s.