Like Puzzles? Solve This One Faster Than I Did

Midpack

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This is just for fun, if you like puzzles - I assume most readers won’t be interested. I don’t think there is an easy solution, but I’m fine with it as is now that I understand.

We like having our outside lights on at night, and we’ve used aftermarket light controls/photocells (pic below) to automatically turn them on at dusk and off at dawn.

Our new house has a light outside the garage with two bulbs (pic below). So I went to HD and bought two light controls and put them between the bulb and the light socket as always.

Last night at dusk, DW went to check and said garage light is on (light control working) but one bulb is burned out. I was pretty sure both bulbs were good so I went out to check, sure enough only one bulb was lit.
  • I took the globe off and both bulbs lit up :confused:
  • I put the globe back on, left bulb went out.
  • Took globe off, both bulbs lit, and I changed the aim direction of both light controls.
  • Put globe back on, right bulb went out.
Went back and forth several times and found.
  • With globe off, both bulbs lit.
  • With globe on, only one bulb lit BUT could be either one :confused:
It took me about an hour, but I think I figured out what’s going on :facepalm: :LOL: - but there’s no easy solution. Only one bulb will be lit every night.

Do you see what’s going on?
 

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The one that comes on first makes the second inoperable because of the light cast and reflection off the globe.

Take the glass out of the fixture and see if it work, maybe no reflection.
 
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Maybe I am making this too simple. It seems to me that there will always be one sensor that "sees the dark" first (shadows, other light sources could change which one this is). When globe is on, there is enough reflected light from the first bulb to prevent the second sensor from activating. When the globe is removed, no reflected light, both sensors detect dark.
 
Yep, and the globe is probably reflecting light back to the second bulb.
 
Maybe this is ideal. Is it overridden by a switch, and/or when you open your garage door? If so, you get both bulbs on when you really need it, and one light on the rest of the time when there's less of a need, unless you have a real security need. I'd probably take the sensor out of the one that casts light where you need it less, to make sure the one you really want on comes on. Maybe you can return the other one.
 
Maybe this is ideal. Is it overridden by a switch, and/or when you open your garage door? If so, you get both bulbs on when you really need it, and one light on the rest of the time when there's less of a need, unless you have a real security need. I'd probably take the sensor out of the one that casts light where you need it less, to make sure the one you really want on comes on. Maybe you can return the other one.

Not sure that would work. Wouldn't that mean that bulb would stay on all the time? Day and Night?
 
The one that comes on first makes the second inoperable because of the light cast and reflection off the globe. ...

Exactly what I was thinking. Not sure if it would work, but try positioning the sensors in opposite directions.... one to the right and the other to the left.
 
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Then if it is the case that the second one doesn't go on because the light of the first one reflects back, why wouldn't it likewise turn itself off for the same reason? Or cause itself to flicker on/off continually, or cause both to continually go on/off with one on and one off?

Maybe it has to do with the angle which the light is reflecting back and hitting the sensor of the second? Can you twist the base on so the sensor of the second faces in a different direction?
 
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Put some black electricians tape on the globe of the light that's not coming on, you shouldn't need a lot, and shouldn't alter the "look" of the light. Like others mentioned, the reflection of one light is overriding the photocell..
 
Put some black electricians tape on the globe of the light that's not coming on, you shouldn't need a lot, and shouldn't alter the "look" of the light. Like others mentioned, the reflection of one light is overriding the photocell..

This will not work - because the light switch is always on - the photo cell is what is controlling if the power flows through to the bulb. If you put electrical tape to cover the sensor, it will always be lit.

An alternate solution is to have a programmable timer switch and not use the photo cell bases.
 
We have a similar set-up, two dual bulb lanterns, one on each side of the garage. I put the lights on one timer. It's not as precise (on at dusk and off at dawn), but they are LEDs and don't use much electricity.
 
This will not work - because the light switch is always on - the photo cell is what is controlling if the power flows through to the bulb. If you put electrical tape to cover the sensor, it will always be lit.

An alternate solution is to have a programmable timer switch and not use the photo cell bases.

I wanted the tape put on the inside of the globe to prevent the reflection lighting the sensor. Don't cover the sensor.
 
I wanted the tape put on the inside of the globe to prevent the reflection lighting the sensor. Don't cover the sensor.

The bulbs are both in the same globe. It would probably take a bit of trial and error to figure out where to place the tape and how big a piece would be needed.
 
Buy LEDs and let them burn all day. It's cheap.

Change the light fixture.

A timer in the switch, or a sensor can be added to the switch, not a sensor on the bulb.

Turn the sensor 180 degrees from each other. You may have to bend the tab in the bottom of the socket to maintain contact if it unscrews too far.

Try a piece of electrical tape to make the aperture smaller. Enough so that full sun turns it off, and the light next to it does not. Maybe a hooded effect?

A combination of the above.
 
As I suspected, many of you figured it out faster than I did. I was sitting in the fam room with DW when it dawned on me, and I broke out laughing. The globe is reflecting light all around inside and the bulb that’s on is “telling” the other it’s daylight out and shuts it off. Once the globe is on, it doesn’t matter where the photocell is aimed, 180 doesn’t work either, I tried lots of orientations before it dawned on me. The timer is an interesting solution (DW might want it), but it think I’ll just pull one bulb and cover the socket, bulbs and light controls will last twice as long. The light is ornamental (small base bulbs) so it doesn’t matter how much light it puts you. Hope you enjoyed the puzzle.
 
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not as easy as screw-in sensors (and don't even know if they exist) but a single sensor wired in before the light fixture should allow both bulbs to come on as they normally do.
 
We solved a similar problem by switching to LED and now just leave them on all the time.
 
Whatever you do, change to LED. We have a total of 5 porch/garage lights that are on dusk-to-dawn. I bought a 6-pack of A19 8w LEDs with built-in sensors. It was around $30 on Amazon for the 6. The energy saving is significant for anything that burns that long.
 
Whatever you do, change to LED. We have a total of 5 porch/garage lights that are on dusk-to-dawn. I bought a 6-pack of A19 8w LEDs with built-in sensors. It was around $30 on Amazon for the 6. The energy saving is significant for anything that burns that long.
You may not have noticed in my earlier post, but my garage light has small base (E12?) bulbs, the bulb you’re describing is the more USA common E26. I’ll see if I can find an outdoor LED with an E12 base.

[edit] Found one but it won’t work in my fixture anyway https://www.amazon.com/Night-Sensor...+bulb+outdoor&qid=1566233659&s=gateway&sr=8-5
IMPORTANT NOTE: MAKE SURE THAT THERE SHOULD BE A CERTAIN DISTANCE BETWEEN THE TWO BULBS (MORE THAN 3.28 FT) DUSK TO DAWN BULBS:
 
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I have had an occasion where a single bulb interfered with its own sensor, and caused flickering.
 
You could try gluing a small black tube maybe an inch long where the sensors are so the sensors are only looking at light outside the fixture.
 
Fixtures are cheap and easy to change. Just switch to a fixture that has only one standard-base bulb. Buying should cost well under fifty bucks and changing it shouldn't take more than ten minutes.

Alternatively, buy one of the outdoor integrated LED fixtures with a built-in control sensor. We have a couple of these lighting the garage sidewalk at home and one lighting the parking area at the lake home: https://www.homedepot.com/p/Defiant...ated-LED-Security-Light-DFI-5982-BZ/300486584 Probably there are more attractive fixtures of this type, too.
 
I say leave it as is and use as a sort of Magic 8 Ball.
 
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