IR thru glass

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Robert Reed
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IR thru glass

Post by Robert Reed » Sun Dec 18, 2005 9:28 pm

I know this will sound like a trick question because of its simplicity. I am in the process of building a large entertainment center and just beginning to build some cabinet doors that will house some remote operated equiptment. Suddenly, the thought occurred to me about what might happen when passing IR signals thru these glass doors.. My initial thought is nothing, but lacking a handy piece of glass to run in and try this on my TV, I thought I would just post this query to some of you that may be already doing this. My concerns are:
Is there any attenuation of the signal and are there any critical angles of coincidence involved?

2M MACHINING
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Re: IR thru glass

Post by 2M MACHINING » Sun Dec 18, 2005 9:53 pm

Robert, I have my ststem behind smoked glass & I have not noticed any degredation in operation of IR.
Go for it
Mike M

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Edd
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Re: IR thru glass

Post by Edd » Mon Dec 19, 2005 2:12 am

R-uh R-uh:
No problem here, also with dark smoked glass. However, if the equipment is spread across laterally quite a bit, such that the sensor is hit from an oblique angle a decrease in overall range might be expected. E.G. testing here in a direct frontal lobe entry of signal, a 27 feet range is possible, but an oblique hit decreases to an ~ 15 ft range.

73's de Edd
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jwax
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Re: IR thru glass

Post by jwax » Mon Dec 19, 2005 4:09 am

Probably not a problem with typical window glass, but glass can be formulated to block IR, UV, or other spectrums.
Take your remote and an IR detector card (RadiShack) with you when you buy the glass.

Robert Reed
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Re: IR thru glass

Post by Robert Reed » Mon Dec 19, 2005 9:57 am

Thanks fellas
I will now proceed with glass doors.

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Chris Smith
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Re: IR thru glass

Post by Chris Smith » Mon Dec 19, 2005 10:23 am

IR Light is the best frequency of light for bounce situations. I often bounce it off a wall around corners, or even use the shine on my eye ball to bounce the frequency to a better spot in the room and a neat trick is to use your eye ball, then close your eye lids and the bounce stops all together.

If you stare at the sensor while pointing the remote at your eye, your reflective angle lines up even better with the TV if things like tables and chairs happen to be in line of sight and blocking your hand from lining up with your TV.

The weaker the IR led, the better this works.

Dean Huster
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Re: IR thru glass

Post by Dean Huster » Mon Dec 19, 2005 5:13 pm

A twinkle in your eye there, Chris? When's it due? :>)

I know it works well through glass. We had an instructor that we liked to mess with all the time who was showing a video recording to a class. Another instructor and I got into a darkened office across the hall from the target VCR with a remote and through two 1/4"-thick panes of safety glass, screwed around with his VCR until he about went nuts. He never did figure it out until we told him what we did a couple of days later.

Dean

<small>[ December 19, 2005, 05:14 PM: Message edited by: Dean Huster ]</small>
Dean Huster, Electronics Curmudgeon
Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines).

R.I.P.

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Chris Smith
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Re: IR thru glass

Post by Chris Smith » Mon Dec 19, 2005 7:38 pm

Dean

That trick works even better if you replace the IR LED with a IR laser diode, then climb the tallest structure or mountain in your town and drive the whole town and your cable company batty.

If you have a single cable company in town and use their remote for the common connection, the laser will reach a wide birth with plenty of strength and beam width at a mile or more to take out whole neighborhoods at a time.

It will be in the papers by morning.

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jwax
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Re: IR thru glass

Post by jwax » Tue Dec 20, 2005 7:02 pm

Wow! Forget the threat of an EMP weapon!
Think of the devastation, frustration, disgust and riots that would follow an IR invasion of TV sets! Random channels! Volume Up, Volume Down!
Pure Pandamonium.
Oh! The Humanity!

cato
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Re: IR thru glass

Post by cato » Thu Dec 22, 2005 4:52 am

So THATS what those damn carolers were going on about:

Go, tell it on the mountain, ,
Over the hills and everywhere
Go, tell it on the mountain,
That Jesus Christ is born.


While shepherds kept their watching
Over silent flocks by night
Behold throughout the heavens
There shone a holy light.


Go, tell it on the mountain,
Over the hills and everywhere
Go, tell it on the mountain,
That Jesus Christ is born.


The shepherds feared and trembled,
When lo! above the earth,
Rang out the angels chorus
That hailed the Savior’s birth.


Go, tell it on the mountain,
Over the hills and everywhere
Go, tell it on the mountain,
That Jesus Christ is born.


Down in a lowly manger
The humble Christ was born
And God sent us salvation
That blessèd Christmas morn.


Go, tell it on the mountain,
Over the hills and everywhere
Go, tell it on the mountain,
That Jesus Christ is born.

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