IR LED's Focusing

Discussion in 'The Projects Forum' started by Chris15, Oct 8, 2009.

  1. Chris15

    Thread Starter Active Member

    Apr 15, 2009
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    Hi
    I have some TV Remote IR LED's and i want to know the best way to focus them into the same way as a torch does for example;
    I have a 10 LED Bright White torch that uses 3 AAA's if i open it up and replace the LED's with the IR ones, will it have the same Lumen output as the White LED's?

    Thanks Chris
     
  2. BMorse

    Senior Member

    Sep 26, 2009
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    depends if the IR LED's have the same beam angle and wavelength output as the white ones.... most TV remote IR LEDs have a narrow beam angle, so your IR light would be more focused per LED, if you had a way to view it, (such as a video camera with night vision) or any cheap digital video recorder, you should be able to power one of the IR led's and aim it at a wall, you should be able to see the round IR beam pattern on the wall, which should get wider the further you back up from the wall.

    I had taken one of those crank flashlights that you have to hand crank to charge, it had 3 white leds (ran on a 3 way switch, 1 position the leds are all off, 2nd pos, both outside leds are on, 3rd pos middle led was on, so I could change from visible light to IR with a click of a switch), I took 2 of them (the out side ones, left the original white in the middle, and replaced them with those same kind of IR LED's from remotes.... it works great with one of my hacked one time use camcorder that I turned into a night vision camera by replacing the IR lens filter.... The only problem you will find is that, your batteries wont last as long, and that the IR LED's dont like to have constant power applied to them, they tend to over heat and burn up quite frequently. thats why they are pulse modulated, not only to ignore ny ambient noise, but also to give the LED time to cool off in between pulses....

    My .02
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
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    Of course, you meant to say something other than
    They would not be IR if so.
     
  4. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Lenses that work for visible light do not work for IR and vice-versa.
     
  5. beenthere

    Retired Moderator

    Apr 20, 2004
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    If plastic, they may sharply attenuate at the IR wavelength.
     
  6. BMorse

    Senior Member

    Sep 26, 2009
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    :eek: My mistake, I just meant the beam angle, not wavelength....
     
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