Looking for help identifying a photo sesnsor

Discussion in 'General Electronics Chat' started by kbirecki, Oct 9, 2011.

  1. kbirecki

    Thread Starter New Member

    Oct 22, 2009
    I am looking for help identifying the attached photo sensor. It came from a lawn light and is supposed to turn the light on at dusk. It runs on a 1.2V rechargeable battery. I have many of them and they are corroded and I want to replace them. I'm trying to find the right part that I can order from DigiKey or Mouser. Any assistance to point me in the right direction would be appreciated.
  2. BMorse

    Senior Member

    Sep 26, 2009
    those are CDS photocells, unfortunately, unless you can read the value of that one with a multimeter, you may not find the exact value for replacement, if you can unsolder that one and take resistance readings from it in complete darkness and exposed to the brightest light source, then you may be able to narrow it down to a specific one....
  3. #12


    Nov 30, 2010
    Kinda looks like a Cadmium Sulphide photo cell. They are available in several resistance ranges. Not my specialty, but you can measure a good one in daylight and darkness, then search datasheets like this one. Somebody that has been playing with those lately will be along in a moment.
  4. kbirecki

    Thread Starter New Member

    Oct 22, 2009
    Aha! I do have at least one that is still looking decent, so if I can get two good resistance values (light and dark), I should be in the right direction.