BILL and other LED GURU's IR LED POWER LIGHT

Discussion in 'The Projects Forum' started by bigcape, Oct 10, 2009.

  1. bigcape

    Thread Starter Member

    Sep 18, 2009
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    I had an idea for an IR array that I could not get a polite response. So I have withdrawn my questions
     
    Last edited: Oct 11, 2009
  2. Audioguru

    New Member

    Dec 20, 2007
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    Who are you snooping on in the dark? Why?
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    A IR LED is just another LED, but has a lower Vf. Treat them as normal LEDs with around 1.5V Vf (best use the LED datasheet for the exact voltage).
     
  4. bigcape

    Thread Starter Member

    Sep 18, 2009
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    Who says you gotta be "SNOOPING"?

    The uses are endless:

    1. Photography- above and below the surface (underwater)
    2. Videography - " " "
    3. Nature watching undisturbing natural behaviours
    4. law enforcement/ private security
    5. FUN
    6. Finding you way to your favorite hunting spot in the dark.
    7. Hiking
    8. Camping
    9. Fishing
    10. Seeing in the Garage when the light bulb burns out.
    11. Any night time activity that a regular flashlight is an annoyance.

    thats just a few
     
  5. HarveyH42

    Active Member

    Jul 22, 2007
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    I've built a few for my security cameras. Get LEDs with a data sheet, you can pulse them at a higher current, and increase the range considerably. My DVR records at 30 fps, and I don't notice any flicker. The IR LEDS used in remotes can take a lot of current pulsed, as intended. Think they are a little more robust than visible spectrum LEDs.
     
  6. bigcape

    Thread Starter Member

    Sep 18, 2009
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    That is what I really need. What do you mean by "pulse"?

    I want to create an array of 50 to 100+ to throw out a beam.

    Any schematics out there?
     
    Last edited: Oct 17, 2009
  7. HarveyH42

    Active Member

    Jul 22, 2007
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    You need to get LEDs with a data sheet, so you know the current and duty cycle. I used a 555 wizard (don't have the link on this computer) to generate the signal (more or less), and only about 3/4 the max current the LEDs could handle, since the 555 isn't very stable with temperature changes. This was several years ago, and after you solder 72 leds, you'll understand why I didn't do more... Really don't have the files handy for that one, didn't move them over to this Vista machine.

    It's really not a tough one to work out from the data sheet of the LEDs you get, that's why it's important. It is kind of a custom job, don't think it's the same for all IR LEDs. The pulsing, is really Pulse-Width-Modulation. You need to provide a certain amount of off time, for the LED to run at a safe temperature.
     
  8. Wendy

    Moderator

    Mar 24, 2008
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    OK, so you're using average power to rate the LEDs, but how are you calculating peak power that is safe?

    What aspect of a 555 is temperature unstable? Frequency definately, since we are talking an RC oscillator, but I suspect PWM ratio is pretty stable. I've never heard any reason to assume otherwise.

    To the OP, what is the intended power supply voltage?
     
  9. bigcape

    Thread Starter Member

    Sep 18, 2009
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    The real goal is to make IR spot lights and IR flood lights, per se for the purpose of aiding my security cameras to see more.

    In addition a hand held device that is portable.


    Sooooo, for the "mounted" arrays of 75 IR LEDs or more will mount to a building. I have tonnes of 12VDC 300-500mA left over power supply's that seem to just fall out of my closet!

    The hand held device for nature photography will run off of four 1.5VDC "C" cell plain 'ol batteries.

    I don't understand why I would a 555 in the mix
     
    Last edited: Oct 17, 2009
  10. HarveyH42

    Active Member

    Jul 22, 2007
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    I used a couple 555s in a circuit to scare off cats many years ago (still working, sort of). It was meant to send out a 21 kHz beep, every 15 seconds. Most of the time, you can only here a click from the speakers, but in the winter you can hear a tone. Don't know about the PWM, I use microcontrollers for that.

    Get the Data sheet for the IR LEDs. It didn't take me much thought or effort to figure out what I needed to do.
     
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