Calling all fiber optics wizards - strange request (installation, work, memory)

[Tek_Freek]

An interesting problem that requires a solution where all the standard options have failed.

Garage door opener.

During certain times of the year at certain times of the day the garage door will not close. The culprit seems to be the sun crossing the beam for the safety switch. I have to hold the button on the wall until the door closes then go out through the front door. PITA. The door works flawlessly except when the sun is striking the front of the garage. Where I live it's pretty much always sunny so the problem persists for most of the summer.

I've switched the sender and receiver, and placed some black pipe insulation at the ends of each to lengthen the distance before the sun crosses the path as much as possible. Any longer and the door hits them.

Nothing works. I am going to do a quick rewire just to check if the heat is causing a problem with a cracked or broken wire in the wall, but I have little hope of success.

Today I realized that if I placed PCV pipe around the top of the door and back down with mirrors in place I would completely avoid the problem. Seems a bit kludgy, but if I set the mirrors so I can adjust them and tighten a screw down to keep them in place it should work.

Then I thought of fiber optics. I've done some research online, but can't really find an answer, or didn't recognize it when I saw it.

So my question is this: Will a fiber optic cable transmit the infrared beam up and over the garage door, back down the other side and have the beam in a condition that the receiver will recognize it?

Man, I hope someone here is knowledgeable enough to answer this.

[bigbear99]

Depends on the fiber. Plastic, no. Glass, probably, but you probably can't buy short lengths of glass fiber.

Why would you want to defeat the safety interlock? I'd just reverse the position of the sending unit with the receiver.

[jaypee]

Is it because the sunlight is hitting the IR sender/emitter? If so, have you tried putting a "shade" on the emitter?

[lvmensch]

I would presume it is some sort of agc on the sensor doing you in. The sun overwhelms the original light source and then senses dark when the door shuts off the sun. One solution that may work is to back the sensor up six inches or a foot so it is out of the sun. A number of people have fixed it with a length of toilet paper tube as a sun shade on the sensor. Used three inches of 1/2 inch tube to shield on a copier years ago.

I believe the literature has the spectral transmission of the the various fibers. From memory glass works better but my 45 year recall may not be great. I also suspect mirror and fiber is overkill...

I have seen at least two homes where the problem was solved by mounting the sensor and source next to each other. I would not do it with small children or dogs or cats around.

[JonahWicky]

My opener (Genie brand) notes in the installation instructions to mount the emitter unit on the side that gets the least direct sun. Like bigbear said, try switching them. Don't try to defeat the safety system!

[Tek_Freek]

First, thank you for replying. It's appreciated.

Originally Posted by Tek_Freek

I've switched the sender and receiver, and placed some black pipe insulation at the ends of each to lengthen the distance before the sun crosses the path as much as possible. Any longer and the door hits them.

I'll start at the top.

As I mentioned in my OP I have tubes extending from both emitter and receiver. Mine are longer than the one in the picture and extend from both sides.

As I mentioned in my OP I have reversed the emitter and receiver as a test. I checked the light colors so I know they are in their correct positions now.

I am going to try setting the units (emitter first) farther back to see if that helps. Good suggestion.

I appreciate the suggestions. I would appreciate it more if you would actually read my OP before giving suggestions to do things I've already done. Call me frustrated and grumpy and forgive my bluntness.

I don't want to bypass the safety feature of this door, but if I can't get it to work without doing so, I will. No children or pets here so it's not much of a concern.

One of the frustrations with all this is that sometimes when I back out and the door won't close I can pull forward until the truck shadows the emitter and the door will close. Other times it makes no difference.

I hate inconsistency when dealing with this kind of problem. Makes it very difficult to zero in on the cause.

[froglipz]

Make a sun shade to block the direct light, something along the line of the cardboard tube idea above.

[Tek_Freek]

Good idea, and I thought of that. The problem is the whole thing starts late enough in the day that the shade needs to be in front of the garage and at an angle towards the driveway. That's why pulling the truck closer works sometimes.

That means it would be in the way when I back out.

This whole thing is just stupid and it's driving me nuts.

[jaypee]

Originally Posted by Tek_Freek

I appreciate the suggestions. I would appreciate it more if you would actually read my OP before giving suggestions to do things I've already done. Call me frustrated and grumpy and forgive my bluntness.

Read this

I've switched the sender and receiver, and placed some black pipe insulation at the ends of each to lengthen the distance before the sun crosses the path as much as possible. Any longer and the door hits them.

and didn't know that when you were saying "to lengthen the distance", you meant "to block the sun from hitting the sender", but ok.

[bigbear99]

Try spraying black paint on the inside of your baffle tubes, not just at the ends.

Have you ever thought of ignoring the posts you don't like, like from those of us who don't re-read your initial post every time, and are just trying to help?