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iLearn

join:2013-01-16
canada
reply to iLearn

Re: Garage door problem

oh wow.

I just tried the garage door several times and it worked fine.

So was it not working because of the nunya's sun light theory? I did not change any settings. damn.

But I have lived in this house for 3 years and was it just the coincidence that I never operated that door exactly at the time when sun is shining at the eyes? who knows?

If it happens again then I will play with the force setting as others suggested.


Austinloop

join:2001-08-19
Austin, TX
kudos:1

I have nunya's sun problem sometimes during the year. I solved the problem by taking some cardboard and making a sleeve to shade the lens of the sensor from the sun. Not particularly elegant, but it beats the heck out of trying to rotate the house 30 to 45 degrees.



sempergoofy
Premium
join:2001-07-06
Smyrna, GA

I did the same cardboard trick. I still have the problem sometimes during the year. I may have addressed it once by swapping the two sensors. I think one transmits and one receives.
--
nohup rm -fr /&



nunya
Premium,MVM
join:2000-12-23
O Fallon, MO
kudos:12
reply to Austinloop

I did the "cardboard trick" too. It helps, but it's still not 100%.


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1
reply to iLearn

said by iLearn:

But I have lived in this house for 3 years and was it just the coincidence that I never operated that door exactly at the time when sun is shining at the eyes? who knows?

Perfectly aligned system will not be bothered at all by the sun ... unless you have a glass wall or a huge hole right behind the transmitter. The simple reason is that the receiver-to-sun straight line will be at least 15 degrees away from the receiver-to-transmitter straight line for a proper garage door setup.

It is possible that the aiming was off by a few degrees during install but still allowed the transmitter beam to fall on the receiver lens with sufficient intensity. However, the bad aiming also allowed the sun to fall on the lens.


nunya
Premium,MVM
join:2000-12-23
O Fallon, MO
kudos:12

I set mine with a laser level. Still does it. I think it's just "one of those things" that you laugh at and live with.
--
If someone refers to herself / himself as a "guru", they probably aren't.


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

said by nunya:

I set mine with a laser level. Still does it. I think it's just "one of those things" that you laugh at and live with.

It may be just a nuisance to most people but home/personal security could be compromised on rare occasions. Since you have the most experience with this problem, please record a demonstration video during the next sunset and kindly upload it.

It is possible that some receivers were assembled with a wide angle lens by mistake. The receiver's acceptance angle can be easily checked.


jack b
Gone Fishing
Premium,MVM
join:2000-09-08
Cape Cod
kudos:1

Depending on the garage orientation I would think switching the transmitter with the receiver should eliminate sunlight caused issues. Or, simply glue on a short piece of PVC pipe as a "blinder" to the receiver "eye".
--
~Help Find a Cure for Cancer~
~Proud Member of Team Discovery ~


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

said by jack b:

Depending on the garage orientation I would think switching the transmitter with the receiver should eliminate sunlight caused issues.

Thank you. I really wanted someone else to point out the ONLY CORRECT position for the IR receiver is where either sunrise or sunset can't interfere with its operation.

It makes no sense to align the beam perfectly using a laser when the sensor was installed on the wrong side.

said by jack b:

Or, simply glue on a short piece of PVC pipe as a "blinder" to the receiver "eye".

Another common sense solution.

Older design IR sensors were not very selective spectrum-wise and needed to be put in a short tube with a very narrow angle lens. But this person still had a problem with the sun and fixed it using a tube from toilet paper roll.

Better designs use IR sensors which are matched to the transmitter wavelength and also modulate the transmitter beam to make sure the system is not confused by external IR sources.


nunya
Premium,MVM
join:2000-12-23
O Fallon, MO
kudos:12
Reviews:
·Charter
·voip.ms
·surpasshosting

Kind of hard and expensive to reorient my house (faces north). Think about it before saying "it makes no sense". There is no "wrong side". There's either the "deal with it in the morning" side, or "deal with it in the evening side".

It's not as big of a deal to me as it may be to others. I can hold the button down, wait 15 minutes for the sun to move, or have one of my kids stand outside so their shadow is covering the eye.

I'll try the TP tube though. It might work better than my cardboard blinder.
--
If someone refers to herself / himself as a "guru", they probably aren't.


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

2 edits

said by nunya:

Kind of hard and expensive to reorient my house (faces north).


No need to reorient your house. Just swap receiver and transmitter - many have wing nuts to simply that process. The original installer just did not think about it.

said by nunya:

Think about it before saying "it makes no sense". There is no "wrong side". There's either the "deal with it in the morning" side, or "deal with it in the evening side".

Moving the receiver to avoid potential solar interference around sunrise or sunset would not cause interference during the opposite daily event. That is true for any practical garage design even for perfectly east-west oriented houses located on the equator.


LazMan
Premium
join:2003-03-26
canada

1 recommendation

reply to nunya

Wow - some people just itching for a fight debate around here these days...


robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1
reply to lutful

said by lutful:

said by nunya:

Think about it before saying "it makes no sense". There is no "wrong side". There's either the "deal with it in the morning" side, or "deal with it in the evening side".

Moving the receiver to avoid potential solar interference around sunrise or sunset would not cause interference during the opposite daily event. That is true for any practical garage design even for perfectly east-west oriented houses located on the equator.

Please explain why you believe this

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

Click for full size
Google Sketchup has a sun path simulator which can be used to model the front of a garage in 3D and check this theory.

I drew a quick sketch of how this problem could happen on some setups. The sun's path will be at an angle from the beam's path and the opposite side will not see the sun because of the wall.

With perfect east-west orientation at the equator, the sun's path will actually be blocked by both sides of the garage.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1

But you are only thinking about a single day of the year. The sun does not rise and set from the same point every day. Therefore what you need to show is that it would be impossible for the rising sun to affect a sensor one day and days or months later the setting sun could not do the same if the sensors were reversed.


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

said by robbin:

But you are only thinking about a single day of the year.

Curiously I had mentioned Google SketchUp sun path simulator to avoid this type of assumption about my thinking process.

All manufacturers ask installers to choose the least sunny side for the receiver because it can be determined easily and the depth and height of the beam can be adjusted within specified limits to account for both summer and winter.

I previously mentioned that modern sensors modulate the beam to reduce solar interference ... which can also come from shiny garage wall/floor/cabinets.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1

There is no least sunny side if the sun rises on one side of the door, shines on it all day, and sets on the other side.


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

said by robbin:

There is no least sunny side if the sun rises on one side of the door, shines on it all day, and sets on the other side.

You can choose whatever location you want and you will see that there is always a least sunny side. Even in the far north during winter with garage facing due south.

»astro.unl.edu/naap/motion3/anima···ions.swf

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1

There is always a least sunny side of the house but not necessarily a least sunny side for the garage door opener sensors. The site you linked did nothing to prove your point.


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

1 edit

said by robbin:

There is always a least sunny side of the house but not necessarily a least sunny side for the garage door opener sensors.

That is not actually my choice of words ... imagine you are the installer and you find that instruction in the manual.

Do you have a problem because you are thinking both east and west sides are equally bad for the sensor when a garage door is facing due south in the northern hemisphere?

Or are you having a problem because you realize both sides are equally good since the sun is always outside the sensor's acceptance angle?

said by robbin:

The site you linked did nothing to prove your point.

Check the sun-sensor-source angle at 15 minute intervals between 6am-9am and 4pm-7pm (local time) from September 21 to March 21. The side which ends up with more obtuse angles is the less sunny side ... just for the purpose of proving that point.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1

said by lutful:

Check the sun-sensor-source angle at 15 minute intervals between 6am-9am and 4pm-7pm (local time) from September 21 to March 21. The side which ends up with more obtuse angles is the less sunny side ... just for the purpose of proving that point.

What good would that do when the sun doesn't set until about 8:30 here in the middle of the summer.

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

said by robbin:

said by lutful:

Check the sun-sensor-source angle at 15 minute intervals between 6am-9am and 4pm-7pm (local time) from September 21 to March 21. The side which ends up with more obtuse angles is the less sunny side ... just for the purpose of proving that point.

What good would that do when the sun doesn't set until about 8:30 here in the middle of the summer.

I lived in Edmonton (10PM sunsets) for many years and now live in Ottawa (9PM sunsets) ... both cities have many more garages facing due south than any city in Texas.

FYI the summer sun simply can't shine directly on a sensor that is installed just a few inches inside a due south facing garage door. Does not matter if sensor is facing due east or due west.

You can change the start/end dates and also the morning/afternoon windows for collecting the sun-sensor-source angles ... one side will end up with a few more "obtuse" angles than the other. That is the "less sunny side" to install the sensor.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1

I'm sure it can't in Canada. I live in Texas at about 30 degrees north Latitude. As you get closer to the Tropic of Cancer, you approach the sun traveling through 180 degrees of the sky. As that happens, it is very possible for the sun to hit one sensor in the morning and the other in the afternoon.

I don't see why the sun cannot shine directly enough on a sensor installed a few inches inside a due south facing door. If it is a double width door then it is 16' or 18' wide. Do the math, the angle it can hit at is within the range of sensitivity of the sensor.


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

said by robbin:

As you get closer to the Tropic of Cancer, you approach the sun traveling through 180 degrees of the sky. As that happens, it is very possible for the sun to hit one sensor in the morning and the other in the afternoon.

You can verify from the shadow cast by the stick figure that it is quite impossible "for the sun to hit one sensor in the morning and the other in the afternoon" ... if you define "hit" as a reasonably small acute angle between sun-sensor-source.

Curiously I grew up in a house near the tropic of cancer. When I was 14, I had the good luck to get my own tiny room on the roof which had one window facing due south. My personal interest in the sun's apparent motion across the sky come from that time and I have done proper sun path analysis (for solar panels) since 2003.


robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1

1 edit

said by lutful:

You can verify from the shadow cast by the stick figure that it is quite impossible "for the sun to hit one sensor in the morning and the other in the afternoon" ... if you define "hit" as a reasonably small acute angle between sun-sensor-source

We aren't debating whether it can do it in a single day, but whether at some point in the year it can affect a sensor on one side of the door and at another point in the year it can affect a sensor on the other side. You are of the opinion that it would be impossible and I think it is possible with the likelyhood greater as you move towards the equator but probably more likely towards the tropical latitudes and diminishing in the equatorial region.

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

said by robbin:

We aren't debating whether it can do it in a single day, but whether at some point in the year it can affect a sensor on one side of the door and at another point in the year it can affect a sensor on the other side.


Try early morning on June 21 for one side and late afternoon on Dec 21 for other side. Or any other two date pairs when you think the worst case scenario might happen.

Make reasonable assumptions for the location of the sensor (like x=6 inches from garage opening ; y=1 inches towards the side wall ; and z = 6 inches from floor ) and sensor acceptance angle (like 11.25 degrees for a pathetic design).

said by robbin:

You are of the opinion that it would be impossible and I think it is very possible.

If this was just a matter of personal opinion, I would have stopped arguing long ago.

garys_2k
Premium
join:2004-05-07
Farmington, MI
Reviews:
·Callcentric
·callwithus
reply to robbin

said by robbin:

said by lutful:

You can verify from the shadow cast by the stick figure that it is quite impossible "for the sun to hit one sensor in the morning and the other in the afternoon" ... if you define "hit" as a reasonably small acute angle between sun-sensor-source

We aren't debating whether it can do it in a single day, but whether at some point in the year it can affect a sensor on one side of the door and at another point in the year it can affect a sensor on the other side. You are of the opinion that it would be impossible and I think it is possible with the likelyhood greater as you move towards the equator but probably more likely towards the tropical latitudes and diminishing in the equatorial region.

Actually, it's more likely the further from the equator you go. Think "midnight sun." A north-facing opening, with one inside wall facing east and the other west will have some days around the equinoxes where light will fall (at a low angle to perpindicular) on one wall in the morning and (on a different day) on the other in the evening.

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

said by garys_2k:

... north-facing opening, with one inside wall facing east and the other west ...

I understand what you are thinking, but the during the short time when the sun can hit an east-west oriented sensor at a narrow enough angle ... it will probably be blocked by trees and other homes.

Proper installations put the sensor about 6 inches from garage opening and at least 1 inch back towards the wall. That tiny offset will make the (maximum 15 degree wide) viewing cone stay completely within the garage. Properly designed sensors should reject sun-equivalent brightness between 15-20 degrees which also imply rejecting sun interference at higher angles.

The only problem left unconsidered is reflection from a very glossy floor or object coming into the sensor below 20 degrees.


54067323

join:2012-09-25
Tuscaloosa, AL

1 recommendation

reply to lutful

said by lutful:

It is possible that some receivers were assembled with a wide angle lens by mistake. The receiver's acceptance angle can be easily checked.

Garage door detectors have a wide angle for both the transmitter and the receiver to allow for fast aiming with large tolerances, conversely photo beams for security applications have very narrow beam widths, are IR filtered, highly selective and use a pulse modulated scheme to prevent or minimize interference from external sources of IR.

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

1 edit

said by 54067323:

said by lutful:

It is possible that some receivers were assembled with a wide angle lens by mistake. The receiver's acceptance angle can be easily checked.

Garage door detectors have a wide angle for both the transmitter and the receiver to allow for fast aiming with large tolerances

The transmitter side would create a "flood" instead of a "beam" if it used a wide angle lens in front of the IR emitting diode.

If the sensor side had a wide angle lens "by design" ... it would fail the mandatory compliance test which shines a 500W/3600K photo flood at placed at 15 degrees just 5 feet away. Check the diagram from US regulation ... just above the dead horse.