24v to 12v led strip

Discussion in 'The Projects Forum' started by kenkay, Mar 21, 2016.

  1. kenkay

    Thread Starter New Member

    Mar 4, 2013
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    I have a 24v source and a strip of leds that need to run at 12v. I only have room to make a simple voltage divider to drop the voltage. I used 2, 100ohm resistors at 1/2W but they are getting way to hot. Any suggestions? Should I just bump up to higher wattage resistors?
     
  2. ronv

    AAC Fanatic!

    Nov 12, 2008
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    We will need to know the current of the led strip as well.
     
  3. TheButtonThief

    Active Member

    Feb 26, 2011
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    Have you considered just using a LM7812?
     
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Yep.. Need current draw of the LED strip..

    Or just buy a suitable 12V supply..
    They are cheap...
     
  5. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
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    Your resistors will dissipate the same amount of power as heat that the LED strip consumes and any linear voltage regulator will do the same.
     
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Yep..
    Best solution is to buy the correct power supply or use a switcher type step down DC-DC converter which won't dissipate nearly as much heat as a linear solution.
     
  7. kenkay

    Thread Starter New Member

    Mar 4, 2013
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    Unfortunately we must have a 24v supply so I can't drop it to 12v. Current draw is .250 amps
     
  8. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
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    12V x 0.25A = 3W so you will need a 5W resistor.
     
  9. ronv

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    Nov 12, 2008
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  10. ameli

    New Member

    Mar 21, 2016
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    Hello..just use a switching voltage regulator using Lm2575or2576 ..no heat..no power lost
     
    Last edited: Mar 21, 2016
  11. mcgyvr

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    Oct 15, 2009
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  12. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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    Use an Lm2596 regulator chip.
     
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