AC relay to switch 12vdc ?

Discussion in 'The Projects Forum' started by Mikiver, Dec 30, 2010.

  1. Mikiver

    Thread Starter New Member

    Nov 27, 2010
    Hi all.
    I am attempting to convert an exterior motion light (AC) to run some leds. There will be no other draw from the AC signal aside from the relay.
    I would like to have the AC signal from the motion light switch on or off the independent power to the led array. I am using 12vdc as the led power source, 12 leds total with 3.5 vf @ 20ma each. 3 leds in series with the appropriate resistor, 82ohms. The led array is complete and works fine, drawing 80ma.

    I do not know what is needed to have the AC power switch the DC. I'm sure there is a simple way without getting too complicated.

    Can someone help please?

    Thanks, Mike.
  2. #12


    Nov 30, 2010
    Buy a relay that has a 120 volt AC coil and connect the 12v circuit to its contacts.