Peltier element.

Discussion in 'General Electronics Chat' started by marvellous, Oct 7, 2014.

  1. marvellous

    Thread Starter New Member

    Oct 7, 2014
    1
    0
    Hi. please i'm working on a project that requires temperature sensing and feedback. i've choosen to use the peltier element as my temperature feedback unit, but i have encountered problems finding a suitable circuit to drive the peltier. Could anyone with previous experience using the peltier please share relevant information with me.
    Thanks.
     
  2. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    they take dc, the voltage max is determined by the spec sheet. to heat current flow one way, to cool, reverse the current. more current - up to the limit inthe specs, more heating or cooling.
     
    marvellous likes this.
  3. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,283
    1,251
    You can drive them with PWM, but not with a voltage greater than their spec.
     
  4. wayneh

    Expert

    Sep 9, 2010
    12,101
    3,036
    For most applications, it's fine to run them with a simple on/off thermostat (bang bang control). You don't need PWM or anything more fancy. Have the thermostat control a MOSFET switch to turn it on and off.

    The biggest mistake usually made with these is to not adequately heat sink the hot side. You need lots of aluminum fins and a fan to dissipate all the heat they make. If you run them near the max specs, they make 10X more heat on the hot side than they remove from the cool side. The cool side will be some ∆T cooler than the hot side, so the more heat you get off the hot side, the cooler the cool side can go.
     
  5. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,791
    1,103
    Won't that just give you a measure of the temperature difference between the hot and cold sides? How will you then get a measure of the hot/cold side temperature of interest?
     
Loading...