12v Dimming Circuit to Trigger

Discussion in 'Power Electronics' started by ChevyLT1Camaro94, Dec 21, 2017.

  1. ChevyLT1Camaro94

    Thread Starter Active Member

    Jan 9, 2009
    Hello, I have a dome light circuit in a vehicle that dims down when you close the door or lock the vehicle. what i need to do is take that dimming circuit and easily (and inexpensively) have it cut off at around 10v. I'm adding auxilary led lights that do not take well to the dimming. I was thinking of using a zener diode but I'm not sure which one i need or how to properly use it. The load it would need to handle is roughly 2A anything more and i would use it to trigger a relay instead. If there's an easier or cheaper way of doing this I'm all ears. thanks!
  2. Alec_t


    Sep 17, 2013
    The dimming is almost certainly done by pulse-width-modulation (PWM) under the control of a microprocessor (MCU), so modifying it is nowhere near as simple as connecting a zener or resistor somewhere in circuit. Without knowing what the existing circuit is, any attempt to alter it could result in having to buy an expensive new MCU module :(.