High power led for DI? 
Posted: 24 November 2007 11:26 AM   [ Ignore ]
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1.5V @ 700mA = 1W despite is being labeled as 3W. Although they are known to mislabel things.
it’s probably 4.5V @ 700mA = 3W as the 3 ships are probably wired in series but you never know.
http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=3247
There is also a 1Watt version here
http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=3245
I would be careful as there seems to be no datasheet or other specifications for them.

Would a few of these work in a DI setup?
Maybe with a large diffuser to prevent hotspot.
Might work for FTIR as well. As most seem to use the larger angle 5mm leds.

How would these hold up in value to the popular osram leds?

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Posted: 24 November 2007 12:44 PM   [ Ignore ]   [ # 1 ]
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For DI they’re probably work well. From the video it looks like you would probably only need 2-4 of them and since the light source is so compact it’d probably be easy to diffuse.  Let us know if you end up trying them. They’re cheap enough where you wouldn’t be loosing out much by trying 2-4 of them out for DI. Much cheaper that buying an IR illuminator.

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Posted: 24 November 2007 06:56 PM   [ Ignore ]   [ # 2 ]
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I think these new high power LED’s are well worth investigating for DI set-ups.  But for FTIR, I would take into consideration the angle of the LED’s which are usually at 90 degrees or more (wide angle) Which is ideal for DI, but may not be desirable for FTIR set-ups because you want narrower beams.  But since they are small, they may be useable for FTIR if they are placed directly on the edge of the acrylic.

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Posted: 25 November 2007 12:12 AM   [ Ignore ]   [ # 3 ]
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Yeah, I agree with nima. I’m doing FTIR right now, but may add in DI. I would definitely consider these. There’s a lot of benefits: very little soldering/wiring, not expensive, and will probably have a nice even lighting. I think 1 of these angled in each corner of a table would work really well. You may not even need that many.

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Posted: 01 December 2007 05:34 AM   [ Ignore ]   [ # 4 ]
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i have found also this one : http://www.led-tech.de/en/High-Power-LEDs/1.0W-ACULED/ACULED-VHL--4chip-IR-LED--LT-1119_55_66.html

seems interesting (and the seller is a well known european site winth shipping worldwide), but i think that heat produced by this kind of high power led may be a problem ...

another interesting stuff is the 120° angle, wich i think is very good for DI

if someone with more electronic skills than me can take a look at the specs and datasheet, it may be helpful smile

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Posted: 29 January 2008 04:20 PM   [ Ignore ]   [ # 5 ]
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Have just ordered 8 of the 4.5V @ 700mA =3W for my FTIR LCD Setup… So give some feedback when i recive them :-p

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Posted: 29 January 2008 05:49 PM   [ Ignore ]   [ # 6 ]
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Let me know how they work for you:

I have ordered a few of them myself but it didnt work out for my new LCD set-up.

I still cant shine IR light through the reverse side of my panel.

Right now; I’m using a 37” HDTV and they are packaged and back-lighted enitrely differently from smaller monitors.  Instead of a light-guide, bigger monitors have a large 1/8” sheet of acrylic that is casted to be diffused.

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Posted: 21 February 2008 08:18 PM   [ Ignore ]   [ # 7 ]
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I am using High-Output Infrared LED (Model: 276-143, Catalog #: 276-143) from Radioshack. Combined with an LED Holder (Model: 276-080, Catalog #: 276-080) it is easily mounted into a metal (plastic or wood) frame with only a little drill work. The larger wavelength lends itself nicely to homebrew camera IR filters such as exposed film and floppy disks which block more and more (tight wavelength) visible light when stacked in layers.  My acrylic is 32"x"18"x3/4” (16:9), though I think thinner for a vertical setup would be optimal, I went thick for a coffee table style vertical setup. Because these IR LEDs are so powerful (bright in their respective spectrum), only about one every two inches will work for a small display like mine.  A larger vertical setup would probably require one every inch, on every side, not just the top and bottom of the acrylic (like most setups).

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Posted: 08 March 2008 08:08 AM   [ Ignore ]   [ # 8 ]
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Have tryed the High Power Led’s on a glass plate, but doesn’t seem to work… So now I need to find a place to buy acrylic here in Denmark for furture teste…

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Posted: 08 March 2008 12:55 PM   [ Ignore ]   [ # 9 ]
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You are right, glass does not support internal reflection of infrared very well.

I strongly suggest to people with limited funds to purchase a small test size piece of acrylic first. Regular paper size (8 1/2"x11") is good because it will fit a whole hand and there is enough room to recognize blob gestures, but it’s not too expensive. For a vertical “wall/kiosk” setup I wouldn’t use less than 1/2” inch thick acrylic, 3/4” inch thick for a horizontal “coffee table” style display. Anything thinner and you have too much bending and warping of the acrylic. Also, these small pieces of acrylic are shippable worldwide for a relatively low price if people on the forum would be willing to share them with other members engaged in materials testing (especially compliant surface material tests). I think that would be great.

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Posted: 08 March 2008 03:20 PM   [ Ignore ]   [ # 10 ]
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Okey… If someone have a piece of acrylic there is about 260 mm x 330 mm - 3/4” thick and would like to sell it for a good price I’ll be glad… Cause then I can test my LCD Setup… Can’t fine anywhere to buy it here in Denmark, cause here it’s overpriced…

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Posted: 24 April 2008 07:16 AM   [ Ignore ]   [ # 11 ]
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So do we have a solution?  I’m looking at the VHL set-up’s also.  We did a test last night on a small A4 size screen (DI) with an array of 28 LED’s and it didn’t work, so tonight we’ll try 48.  We are looking to build a 1500 x 700mm table soon and the IR source is our biggest concern.  I may invest in some of these VHL’s and see how they work.

A.

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