Question:
Garage door opener manual buttons are normally 2 wire, and are a classic
doorbell button application. My mother just had her garage door opener
replaced, and now via the same two wires I installed many years ago, there
is now a button that is lit. The other button (in parallel) is unlit and
still works fine.
Not having one of these modern marvels (lit buttons) to examine for myself,
how do they work?
Answer:
There is a small amount of voltage at the switch to detect the switch
closure, when the switch closes current flows thru the switch to the garage
door opener (or doorbell) to tell it to do its thing.
When the switch is not pressed, the small incandescent light bulb that is
wired in parallel to the switch has current flowing thru it, just enough to
light the bulb, and not enough to trigger the opener (or doorbell). You will
notice the light goes out when the button is pressed.
Now this is how I engage mine again. I have a little arm, that points
down when pulled, removing a pin from a track. when I push that pin
back into a horizontial position, the pin is pushed back into the
track. However, the pin doesn't often line up with the little 'car'
that runs on the chain. So I cycle the garage door openner, and in
the pulling operation, or pushing, it manages to force the 'car' back
under the pin. Then I'm done. This works for me, but I'm guessing we
don't have the same type setup, and door.
