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.

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