Principle analysis of the light control circuit for automatic intermittent operation of 555 daytime

Probe domestic switch needle KG300B head diameter 3.0 normally closed switch needle total length is 5

As shown, the light control circuit includes a multivibrator and a light control switch circuit. The 555 is used as the core to form an unsteady multivibrator with adjustable duty cycle. The charge and discharge time can be adjusted by RP1 and RP2. The phototransistor 3DU6 acts as a photosensitive switch between the output of IC1 and the b pole of VT1.