20A Dummy Load

Discussion in 'General Electronics Chat' started by newhobby, Oct 2, 2014.

  1. newhobby

    Thread Starter New Member

    Mar 26, 2014
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    0
    Hi,

    I need to test a constant current circuit up to 20A.
    My real load is a light diode with about 2.5V forward voltage and I don't want to use it to test the circuit as it is pretty expensive.
    What would you recommend for a dummy load?
     
  2. #12

    Expert

    Nov 30, 2010
    16,257
    6,757
    eight (1) ohm 10 watt resistors in parallel.
     
  3. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    In a tub of motor oil or distilled water.
     
  4. wayneh

    Expert

    Sep 9, 2010
    12,093
    3,031
    Five headlights in parallel will draw about 20A at 12V. No oil bath needed. And you can land airplanes.
     
  5. #12

    Expert

    Nov 30, 2010
    16,257
    6,757
    C'mon guys, 80 watts worth of resistors on a 50 watt supply isn't going to need liquid cooling. :rolleyes:

    and 12 volt light bulbs don't work very well on 2.5 volts. :p
     
  6. wayneh

    Expert

    Sep 9, 2010
    12,093
    3,031
    Haha, yeah, missed that. I even double checked for the OP's voltage but that didn't register. I gave blood last night. Let's blame that.

    The resistors will work just fine. Just let them breathe.
     
  7. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    and very heavy interconnects (wiering between resistors and source.)
     
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