Need help finding high power LED

Discussion in 'The Projects Forum' started by Rob1132, Sep 26, 2014.

  1. Rob1132

    Thread Starter Member

    Nov 4, 2010
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    So a friend of mine asked me to put together a portable light for him to take out in the woods at night. It'd have to be infrared obviously for his night vision camera. I've built those kind of lights before, but with it being outdoors I'm in need of an LED with some serious power. I'm no expert with this stuff so I've been having trouble tracking an LED like that down. It'd need to have a pretty wide viewing angle and as far of a distance as possible (I'm thinking extreme distances if possible). I generally just put my LEDs together in a series and run them off a 9V battery. Thanks for any help I can get.
     
  2. wayneh

    Expert

    Sep 9, 2010
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    You'll need quite a lot more battery power to get useful amounts of IR illumination. Are you wanting a beam or a wide spread? You sort of said "both", which means you'll need a very bright light!

    Is there a reason to not buy a commercial product? Probably cheaper and easier.
     
  3. mcgyvr

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  4. Bernard

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    Last year ??, an OP made a IR Illuminator using a section of large plastic ball to spread the light.
     
  5. Rob1132

    Thread Starter Member

    Nov 4, 2010
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    Ok, thanks for the help. I kind of thought a commercial product or other method would be easier and cheaper, but he still wanted me to do some digging.
     
  6. jjw

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    Dec 24, 2013
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  7. #12

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  8. gerty

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  9. jjw

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    Dec 24, 2013
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    Yes these specifications are often inaccurate.
    At Dealextreme an user had measured similar IR-led with about the same specs:

    "In Tests, the listed Voltage & current specifications didn't add up?
    At 1.5A drive current, the voltage is 2.1V (not 1.5V)
    At 2.0A drive current, the voltage is 2.6V (not 1.8V)"

    So the 5W maybe true.

    If the seller has 99.xx positive feedback and has sold hundreds of items, the risk for a scam is low.
    I have no bad experiencies from buying from Chinese sellers.
     
  10. Rob1132

    Thread Starter Member

    Nov 4, 2010
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    I had seen that one on Amazon and it is super cheap. Only thing is it looks like it needs to be plugged in? Is there something I can do to make it connect to a battery of some sort?

    I found these ones on ebay that weren't too ridiculous price wise....

    http://www.ebay.com/itm/10pcs-3W-In...399?pt=LH_DefaultDomain_0&hash=item4ad4bd095f

    Again, not being an expert on any of this stuff by any means, would those be safe if I strung a few up on a 9v battery? I ran the specs through the LED array wizard and this is what it gave me.

    Solution 0: 4 x 1 array uses 4 LEDs exactly

    +9V
    [​IMG][​IMG][​IMG][​IMG][​IMG][​IMG][​IMG]R = 5.6 ohms
    The wizard says: In solution 0:
    • each 5.6 ohm resistor dissipates 2744 mW
    • the wizard thinks the power dissipated in your resistors is a concern [​IMG]
    • together, all resistors dissipate 2744 mW
    • together, the diodes dissipate 3920 mW
    • total power dissipated by the array is 6664 mW
    • the array draws current of 700 mA from the source.
     
    Last edited: Sep 29, 2014
  11. #12

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    Nov 30, 2010
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    Without telling us where to see it?
     
  12. b1u3sf4n09

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    May 23, 2014
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    Depends on the life you are looking for. It is going to be a tad cumbersome. For example, you could put 10 A23 batteries in parallel and connect them to a power jack to run the light for an hour (not terribly cost effective):

    http://en.wikipedia.org/wiki/A23_battery

    If you want to involve a backpack, you can use a lead acid battery. Cheaper, more options, and longer life:

    http://www.atbatt.com/yuasa-np12-12...KD1QkA9-Y0pi7Zf6NAd9xDZbL_CO1jGTFNxoCvoDw_wcB

    2 lantern batteries in series are probably about the best you're going to get as far as size vs life. You should be able to get 2-3 full nights of use from them:

    http://www.amazon.com/Eveready-Volt-Lantern-Battery-1209/dp/B0043CHX38

    You can use a boost converter to step the voltage up for any combination of dry cell batteries:

    http://www.amazon.com/3-5-30V-4-0-3...id=1412044769&sr=1-3&keywords=boost+converter

    Lot's of options, just depends what you are looking for. This, of course, is specific to the amazon link you pointed out, and most of these are ready-made solutions that would be quick to implement.
     
  13. #12

    Expert

    Nov 30, 2010
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    A 9 volt battery trying to supply 700 ma will be dead in 38 minutes, if it doesn't melt first. Bad choice. :(
    If you want to connect it to a battery, solder some wire onto the two, "feet" looking things.
    You need a heat sink to get rid of the 3 watts of heat! That's why the feet are parallel with the bottom of the LED. It expects you to solder it to something flat to get rid of the heat.

    ps, these are rated at 1.4V, 700 ma. Just so everybody else doesn't have to search that page for the specs.
     
  14. Rob1132

    Thread Starter Member

    Nov 4, 2010
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    0
    Ok so after talking to my friend, it looks like the major need is for this to run off of a 9v battery for convenience since he'll be outdoors. I'm just going to do what I can with that power and rig up some wide project boxes to get as much of a spread as possible. I was thinking of using these LEDs for it...

    http://www.ebay.com/itm/20x10mm-3-C...103?pt=LH_DefaultDomain_0&hash=item35da67e6ef

    Unless anyone else knows of where I can find something stronger that I can still run off of that 9v? Thanks again for all the advice.
     
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