[time-nuts] Cycling of Peltier junction
jimlux at earthlink.net
Fri Sep 10 04:58:50 UTC 2010
Jerome Peters wrote:
> Does anybody know about using the same Peltier junction for both
> heating and cooling? I'm concerned about thermal/mechanical shock
> when changing the polarity back-n-forth between hot and cold. Maybe
> there needs to be a controlled ramp, if so then how do I figure out
> the rate?
Not an issue.. there controllers that basically run AC through the
thing, changing the relative amplitude of positive and negative pulses.
> Why: I'm in the process of building a small environmental chamber for
> my home lab. The volume is ~30 liter, target temp range of 0C to 60C.
> For the cooling side I am using water circulation (radiator, pump,
> reservoir & water block) and Peltier junctions. At first I was
> planning to have two separate systems, one for heating and one for
> cooling, but then I got to thinking that using just the water and
> Peltier could be used for both. I will be using a PID for temp
> control, and two TEC1-12726 Peltier Qcmax(w)= ~240 △T =0j
Yep.. use the same Peltier for both heating and cooling.
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