Garage door sensor circuit?

Discussion in 'The Projects Forum' started by My Tech Guy, Jul 8, 2009.

  1. My Tech Guy

    Thread Starter Member

    Feb 18, 2009
    Our automatic garage door opener has a circuit that is composed of two LED's, one at each end of the door, and while it's closing if you break the beam from one LED to the other, it will stop the door from moving any further.

    What is the formal name for this kind of a circuit, and where can I learn how to build one? :confused:

    Thanks :)
  2. jpanhalt


    Jan 18, 2008
    "Entrapment protection" in the USA. Here is a link to the Federal law:

    The CFR is specific about certification requirements. Building one yourself might improve safety, but should there be an accident, your device would be considered as substandard and not meeting the requirements (you generally cannot certify something after the fact).

  3. millwood


    in its heart, it is just one light source on one end and one light sensor on the other end. when the light sensor doesn't get light, due to objects blocking the line of sight, the door reverses.

    to help out with aiming, they usually have an led on the sensor end to signal if it is getting the light source.
  4. My Tech Guy

    Thread Starter Member

    Feb 18, 2009
    Is there a technical name for that type of circuit? :confused:

    If I wanted to build a kit that did this, what type of kit should I be looking for?

    Thanks :)
  5. KMoffett

    AAC Fanatic!

    Dec 19, 2007