P7 LED Driver Help

Discussion in 'The Projects Forum' started by Justinwat, Dec 15, 2008.

  1. Justinwat

    Thread Starter Member

    Dec 15, 2008
    17
    0
    I working on a 12v project with the P7 LED (3.6v-4.2v, 2800mA). Is there a prebuilt driver out there that will power this LED off of a 12v battery?

    I was planning on using the appropriate resistors to get the voltage where it needs to be, but because other things will be running off of the same battery I am concerned that the voltage variance will damage the LED. So will a driver regulate the output even if the input shifts?

    Thanks for helping this newbie, it is much appreciated.
     
  2. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,173
    397
    Might try LM350 either as V or I reg. It's rated for 3A. National Semiconductor has data sheet.
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    An LM350 with a high-wattage resistor and a LARGE heat sink would work, but most of the power consumed will be wasted in the LM350 and the resistor.

    It's by far the simplest solution that will provide pretty decent current regulation. It will also make for a room heater, at about 25 Watts power dissipation; about 11 Watts in the LED itself. (I hope you have a way to keep the LED cool, or it will have a very short life).

    You really need a synchronous "buck" current regulator, but I don't know of any pre-built regulators in that range.
     
  4. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,347
    Hello,

    It is not out of the box, but perhaps it is possible for you to make.
    http://www.national.com/pf/LM/LM3401.html

    I attached an overview of power led drivers.
    Remove the .txt and you will have it in XLS speadsheetformat.

    Greetings,
    Bertus
     
  5. sjmusic2

    Member

    Aug 6, 2008
    12
    0
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