Flashing wall light control circuit

Shown is a simple flashing wall light control circuit . VD1, VD2, R3 and C2 in the circuit form a resistor step-down half-wave rectifier and
voltage stabilizing circuit, which can obtain 12 V DC voltage for circuit operation. The NAND gate and 2 form a multivibrator. By adjusting the RPI, its oscillation
frequency can be changed, so that the wall lamp lighting can flicker and glow to achieve a satisfactory effect.
    When the circuit starts to oscillate, the output terminals of NAND gates 1 and 2 will alternately appear high and low. When the NAND gate l outputs a high level,
the trigger thyristor VS2 is turned on, and when H2 is lit, the NAND gate 2 outputs a low level , the thyristor VS1 is turned off, and the lamp H goes out.