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From: mpm on 17 May 2010 16:39
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 about
7.8 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!!
-mpm

It's a Sears unit, "Genie", I think?
Pretty hefty size door. 2-car with hurricane braces. Probably a 3/4
horse.
From: mpm on 17 May 2010 17:01
On May 17, 3:39 pm, mpm <mpmill...(a)aol.com> wrote:
> 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 about
> 7.8 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!!
> -mpm
>
> It's a Sears unit, "Genie", I think?
> Pretty hefty size door.  2-car with hurricane braces.   Probably a 3/4
> horse.

Oh, I should also have added...
Each electric eye has an LED.

I suspect one is a transmitter and the other is a receiver. (?)

Anyway, the one with the GREEN LED is on all the time.
The other one (receiver?) has a RED LED which toggles on or off
depending on whether the beam is obstructed.
RED = Clear, RED off = obstructed.

Please note that the LED's behave this way when (I'm pretty damn
certain) they are aimed correctly, yet the door will not close.
(It also might not open, but I didn't test that). And as I mentioned
previously, the DC voltage doesn't seem to change much, if at all
regardless of what the LED's are doing.

-mpm
From: Winston on 17 May 2010 17:11
On 5/17/2010 2:01 PM, mpm wrote:
> On May 17, 3:39 pm, mpm<mpmill...(a)aol.com> wrote:
>> Have a neighbor w/ garage door troubles.

Start here:
http://www.geniecompany.com/GenieCompany.aspx?cid=322

--Winston
From: linnix on 17 May 2010 18:08
On May 17, 2:01 pm, mpm <mpmill...(a)aol.com> wrote:
> On May 17, 3:39 pm, mpm <mpmill...(a)aol.com> wrote:
>
>
>
> > 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 about
> > 7.8 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!!
> > -mpm
>
> > It's a Sears unit, "Genie", I think?
> > Pretty hefty size door.  2-car with hurricane braces.   Probably a 3/4
> > horse.
>
> Oh, I should also have added...
> Each electric eye has an LED.
>
> I suspect one is a transmitter and the other is a receiver. (?)
>
> Anyway, the one with the GREEN LED is on all the time.
> The other one (receiver?) has a RED LED which toggles on or off
> depending on whether the beam is obstructed.
> RED = Clear,  RED off = obstructed.
>
> Please note that the LED's behave this way when (I'm pretty damn
> certain) they are aimed correctly, yet the door will not close.
> (It also might not open, but I didn't test that).  And as I mentioned
> previously, the DC voltage doesn't seem to change much, if at all
> regardless of what the LED's are doing.
>
> -mpm

The signal could be pulsed (modulated), and you won't see them with a
DC meter.
From: Winston on 18 May 2010 10:16
On 5/18/2010 5:41 AM, mpm wrote:

(...)

Did operation improve after you cleaned the lenses?

--Winston
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