Peltier cooler

Peltier module mounted between standard PC CPU cooler and copper plate, powered from 12VDC (PC supply), copper plate with water drops on it. After connecting the supply to the peltier, it starts to cool the copper plate, and freezes the water drops on it, then I remove the power and it starts to warm up.
The peltier is 100W cooling capacity when powered from 15V, since my supply voltage drops to 10V, I am using at its 1/3power, about 30W.

Real time video!

Category:

Science & Technology

Tags:

• peltier

[billtsig96]

if your reverse the leads does the cold side go hot???

[laszlofabian]

@billtsig96 yes, by reversing the current(leads) you reverse cold-hot sides to, direct relationship with current flow.

Thats why peltiers are useless with AC current :)

[painta76]

ok I'm having a little trouble understanding this, i understand that electricity flowing through it causes one side to heat and one side to cool, but how does it do this and with out electricity could you apply heat to one side and get cold from the other and visa versa?

[laszlofabian]

@painta76 Without getting in details, the physics behind are described by The Peltier–Seebeck and Thomson effects. For engineers as myself its enough to know that peltier's are heat-pumps, the flowing DC current will cause a heat flow from cold to hot side, drawing heat away from one side and dumping on the other side and offcourse Joule's law apply also so the heat generated by the DC current will add to the hot side.

[laszlofabian]

@laszlofabian continued:

To summarize: the peltier element will create a temperature difference between the cold and hot size, to have the cold side for ex at: -20C the hot side must be kept at a relative low temperature which means dissipating the pumped heat+ Joule's heat. Without this the peltier will overheat and melt down, you can see that i used a PC cooler with low Rth.

[laszlofabian]

@laszlofabian contined2: the effect is reversible by means of you apply temperature difference you will get a small current, thermocouples work this way.

If you apply heat to one side, you will just heat the peltier, nothing else will happen :)

[billtsig96]

@laszlofabian thanks friend you are the best :)

[coolaidkiller101]

@ryansnider lower the voltage

[ryansnider]

What do you do to prevent condensation?