Infra red light info

[stormin norman]

Any one point me a the basics on infared lights? I have a boatload on a circuit board here...wondering what I might be able to use them for. How do they differ among themselves as far as size....power needs...etc. One size fits all?

 

[davenn]

I assume you are referring to IR LED's ?

show us a pic... in general power requirements are very similar to normal LED's
you could play with making a simple IR remote control, or maybe an IR beam across a doorway to detect some one passing through the door
you could use a bunch of them to light up an area at nite along with an IR sensitive security camera

just a couple of ideas

Dave

 

[stormin norman]

Never posted pics here...tho in other forums I have. Photobucket work for here?

 

[stormin norman]

I believe I have a bad/burnt one in this board. If you look at the one to the right you'll see it's blackened.

This board is in a Royal paper shredder model # ag15x. When I spoke with a Royal rep he told me the beeping noise I hear when I power the unit up is the basket is full. Sometimes when I power it up it works, but soon it starts beeping and won't shred. The two lights sense the shredded paper level in the basket and stop it from running. I could replace the light, but if it got fried because of something else would I be gaining anything? Can I jump across the lights contacts and be good?

 

[stormin norman]

This will be pic heavy but am showing what I have. Pics from basic cellphone so quality lack...This first pic is of a bulb once removed from the board.

The leads are very short on it. I hope I didn't toast them desoldering them to remove them. This next pic is off the board itself.

You can see there are plenty of lights on it. Next pic is the description of what this unit i s.
And finally the source of the unit.

I was told when I called Odyssey that it was part of an audio distribution setup that fed hearing assisted devices. Seemed a shame to throw them away, so have several laying around here.

 

[davenn]

cool, with a panel of that many IR LED's you could flood your lounge room with IR connected to you stereo or TV and use IR receiver headphones

Dave

 

[(*steve*)]

I believe I have a bad/burnt one in this board. If you look at the one to the right you'll see it's blackened.

What you have there is most likely an IR diodes and a phototransistor. The phototransistor detects the light bouncing back from the paper.

Quite often you will find that the epoxy surrounding photodiodes is coloured. This is typically done to help shield them from light of the wrong colour that they may have some residual sensitivity to.

The one which appears blackened may be that way by design. I've never seen a LED "blacken" due to failure.

The fault you have is unlikely due to a failure in a LED or photodiode.

The possible explanations include things like:

1) You're using really IR reflective paper and it gets sensed even though it's nowhere near the top of the bin.
2) There is some IR light leaking into the bin confusing the sensor (have you replaced the bin with something else?)
3) There is something wrong with the sensor circuit.

As a step in diagnosing this, you could place something opaque (and opaque at IR) over both devices (the LED and the phototransistor). This should stop the device from seeing anything and therefore it should not alarm. If this does stop the problem, then your problem is something like 1 or 2 above. If it does not, then either the shredder has a way of checking for these being blocked or it's something like 3 above.

 

[stormin norman]

Original bin, nothing changed there. Papers being shredded are plain ole paper.....copy paper or junk mailings.....bank statements and the such. When you say place something opaque next to the sensors....give me an example please.....Something semi-transparent like scotch tape? Wax paper maybe??? Thanks for the multiple suggestions here.

 

[(*steve*)]

Something opaque like cardboard. I'd also fold it so it goes between the 2 sensors as well to eliminate the possibility of light leakage from one to the other.

edit: and that's OVER them, not next to them. (to cover them and eliminate any light geiting in or out)