Choosing a potentiometer

Discussion in 'General Electronics Chat' started by cpetrosk, Feb 17, 2013.

  1. cpetrosk

    Thread Starter New Member

    Aug 9, 2012
    5
    0
    I am building a hotplate that uses a thermoelectric cooler. To adjust the temperature of it, I want to use a potentiometer to regulate voltage. I am having difficulty selecting the correct one.
    the specs for the thermoelectric cooler are listed below. My power supply is 12VDC. Also, is the potentiometer the best way to do this.

    • 40 x 40 x 3.6mm
    • lmax - 7A
    • Umax - 15.4V
    • Qcmax - 62.2W
    • Tmax - 69C
    • 1.7 Ohm resistance
    • 127 thermocouples
    • Max Operating Temp: 180℃
    • Min Operating Temp: -50℃
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,418
    3,355
    Your TEC will take about 5A at 12V = 60W.
    If you choose a potentiometer it will have to handle as much current and power, 5A, 60W.
    What you need is a variable power supply, not a potentiometer.
     
  3. cork_ie

    Member

    Oct 8, 2011
    348
    58
    I don't quite understand why you are using a thermo electric cooler to control a hotplate.
    If it is just a question of controlling the power to a resistive load to control the temperature, then the best method for 12V DC is a simple PWM controller
     
  4. cpetrosk

    Thread Starter New Member

    Aug 9, 2012
    5
    0
    i am using a TEC because it is magnetic stirrer/hotplate. Can't use a "regular" heater because it will melt the fan with magnets on it that generates the magnetic field.
     
  5. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    Just how hot do you expect the TEC to get?
     
  6. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
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