Light control fan circuit diagram

Photocoupler

Light control electric fan circuit

The picture shows the circuit diagram of the light control electric fan. In the circuit, the time base circuit 555 and the photodiode 2DU1 and the peripheral components constitute a monostable circuit, and the transient steady-state time is determined by the resistor R2 and the capacitor C, that is, T=1.1R2*C. Pressing the component value selected in the circuit, this time is approximately 4 minutes. If you need more time, you can increase R2 or C arbitrarily.