Simple human body automatic sensor switch circuit

Working principle of the circuit: 220 V mains power passes through capacitor C1 and resistor R1.
After the voltage is reduced and the current is limited , it is rectified by the rectifier diode VD1 and filtered by the capacitor
C2 to obtain a DC voltage of about 12 V, which is then stepped down by R2 and stabilized by the voltage stabilizing tube ZD to form a DC voltage of about 8 V , which serves as the power supply for
the entire induction switch . power supply.