Automatic headlight dim switch

Posted on Feb 6, 2014

With this cool circuit integrated to your cars headlight system, you can drive cool headed in high beam. The circuit will take over the duty of low beaming the headlight when vehicles approach against, and high beams the lights when they pass over. The circuit is based on a photo transistor(Q1) for sensing the approaching vehicles and transistor

Automatic headlight dim switch
Click here to download the full size of the above Circuit.

Q2 (BC177) for switching the relays for controlling the headlight. When the light from the opposite vehicle falls on Q2, it`s collector current increases and turns ON Q1. The relay will be activated and the head light will be dimmed. When the vehicle pass over the reverse will happen.

Leave Comment

characters left:

Related Circuits

  • New Circuits



    Popular Circuits

    Toggle Switch with relay
    AVR Programmer with ATMega8-16
    15V Simple FM Transmitter
    Current Mirror for LEDs
    The Wien Bridge theremin
    Two-way touch switch 4
    Video by MAX4102 4103 RF distribution amplifier circuit diagram
    Synchronous electric motor chokes down according to the stator current excitation circuit