Peltier Coolers

[airefresco]

Has anyone ever had much dealings with TEC´s (peltiers)?

I need a small amount of cooling so they seem the obvious choice, but I´m getting conflicting views on controlling them. From what I´ve seen thermostat control is bad for them, PWM is bad for them. So what are you supposed to do?

I have looked at a wine chiller and that I think uses PWM and computer overclockers I assume just use on/off controls.

I don´t want to spend a lot on controller, I´d just make something to incorporate into my project. Any help would be greatly appreciated.

[chemi-cool]

Ask the manufacturers, try gooooooooooooooogle

[Brian_UK]

I was going to direct you to a previous thread which discussed some of these problems.

Changed my mind when I realised that you were one of the major contributors. DOH!

Remember the lady with the vivarium?

[mad fridgie]

It comes down to what level of temperature control you require.
remember that these are DC, so changing the voltage input changes the refrigeration effect. TEC are good thermal conductors when they are off, so it is better to leave a trickle charge going through.

[airefresco]

I was going to direct you to a previous thread which discussed some of these problems.

Changed my mind when I realised that you were one of the major contributors. DOH!

Remember the lady with the vivarium?

Yeah, I remember. In fact I am doing almost exactly the same thing as what is in that thread.

The modules themselves, I have no problem with, I understand the heat sinks and all that. It´s just the controls and power supplies. Temperature wise it´s not going to be cold at all really, I only need a temperature 27ºC and it doesn´t need to be that accurate, within a degree of that will suffice.

If for example, I had 2 supplies (say, 12v and 1,5v) and supplied the TEC with 12v when thermostat on and 1,5v when thermostat off, would that be sufficient to maintain a steady-ish temperature while not damaging the TEC or does the transition need to be smooth?

[desA]

http://www.seattlerobotics.org/encoder/200112/variable.html

Would this kind of variable voltage power supply be useful?

[airefresco]

Possibly if it was made a bit more powerful and robust. I´ve not done the sums yet, but I think that I am going to need about 50watts of cooling, plus fans, etc so I would need a power supply capable something higher than that. Probably 100w power supply would be sufficient. It´s more the method of how to feed the TEC really.

[Brian_UK]

Whichever is used the fans can be fed from a "simple" power supply, maybe cheaper????

[stefen]

yes you can search the answer for your problem at different search engine.