How cool is it to design an Automatic Car Head Lights Turn Off Circuit? Well, I’ve always fascinated myself by playing with car electronics. And today is my day! I’ve come up with a really cool circuit, where you can turn the car headlights “OFF” after a preset time.

This cool circuit is designed using the popular NE 555 IC, and a bunch of associated components. You should be a little careful while testing this circuit actually in a car, where if something goes wrong you’re bound to damage car electronics. I advise you to play with a used car, that you’ve nothing much to lose even if you blow up things.


This circuit when set up in a car automatically turns off the headlight after a preset time after the ignition switch is turned off. So you can walk out easily from the dark garage in the light of your car.

When the ignition switched on first the voltage from the battery is fed to the relay through diode D1. When the ignition switch is turned off it produces a negative-going pulse at the pin 2 that triggers the timer. The output of the IC goes high for the time set by R1. This makes the transistor Q1 to conduct to energize the relay to drive the headlight. After the set time the light goes off. With the value of components used you can make a setting from 10 S to 60 S.


  • Assemble the circuit on a good quality PCB or common board.
  • Fit the potentiometer on somewhere on the dashboard so that you can easily set the timing.

Circuit Diagram & Parts List.

head light turn off



  1. Christo Dreyer

    Hi what switch is one and 2 because from switch 2 the current is flowing directly to the relay.
    this means the ignitions switch is bypassed. and switch 3 , what switch is that because surely this circuit should be wired between the headlight switch and the headlight.

      • sir..the relay is not switching…can u give the specification for the relay …

  2. hello. can i ask what kind if switch can be use for S1 and S2?

    • i mean what kind of switch can be use for S1 and S2

  3. Timothy Gorbunov

    I don’t get how this circuit would work, it seems that s1 does not do anything and from the battery which side is positive and which side is negative

  4. Adrien Cooke

    I have been reading out some of your articles and it’s clever stuff. I will surely bookmark your site.

  5. hello dear friend i want to know about a circuit of Water Motor for automatic off and on option

  6. hi there any value for the relay k1..?
    more details about this circuit and what are the changes do i need to do if the power supply is 24V???
    pls help me with this…thanks

    • admin

      relay can be a 12V, 200 Ohm SPDT relay.