Have a neighbor w/ garage door troubles. Can someone explain (from a voltmeter's perspective) how these things work?
I can get it to work right if I aim the electric eye sensors directly into each other and tape them up, but if I try to actually aim them across the opening, the door will not close. (It may not open either, but I never tested that..)
With both eyes disconnected, the terminals on the back of the main unit read about 12 volts. With one eye connected, that drops to about7.8 volts, and with both sensors, it drops to about 7.3 volts or so. However, I can't really see much meter deflection whether the eyes are aimed or not, even when they are taped together.
However, when taped directly together (so that one sees directly into the other and there is no possible chance for misalignment!!), the door does indeed work correctly.
I'm assuming these electric eyes are current mode?? That might at least explain the lack of a discernable voltage when aligned, not-aligned...?
There are no polarity markings on the electric eyes, and opening up both showed a full-wave bridge (4 diodes anyway that look suspiciously like a bridge!), so I'm assuming polarity does not matter. (?) Either way, the voltage magnitudes did not change much when trying the wires reversed.
Any ideas what could be going on here? Can this really be just an alignment problem, or to you think the eyes are defective? They are newly replaced (before I got involved). I have no idea where the orignal ones went off to.
Thanks in advance!!
It's a Sears unit, "Genie", I think? Pretty hefty size door. 2-car with hurricane braces. Probably a 3/4 horse.