Variable peltiers

[I.R]

Well I've been doin heaps of testing with load/without load of the phase change unit that I have and I've been talking to my friend about the huge temp diff before the compressor kicks back in which is waaaaay too great to be of any use cooling a chip.
Now I can't really change the temp diff too much otherwise the compressor will die (from all the switching on and off) but I was thinking that a peltier that had a thermal resistor that could the adjust the voltage of the peltier (is that right :confused: ) would be an awesome tool to even out the temp.
Has anyone seen or heard of anything like this?

[_N_]

thermal resistor aka thermistor?

you are dealing with high W so you would need to get some good ones, but can't see why you just can't stick in a thermistor?

[Volodkovich]

u'd have to be careful as pelts aren't linear, also, that variable resistor would have to be awesome to cope with the power going through it. It would get real hot.

[Method]

Theres a thread about somthing like this over at ocau but i cant find it >.<

Maby it wasnt, but im sure its the ocau forums, it was about controling the peltier with a rehostat.

[Deviant]

Dummies, you use the thermister to control a transistor or fet that supplies the power to the peltier. You wont find a thermister that will do 10 amps.

[Hans]

I think the closest that I've seen is a temp controlled unit. It turns the peltie on/off depending on the temp, a via temp probe. However, I haven't seen a variable one.

[I.R]

Where abouts did you see the temp prob one Hans

[Hans]

Sorry, I can't recall that as it's in the early days of Thunderbird, Slot A age. There are similar things with the PIII HSF. Have a look around the net.

There used be some info on www.bxboards.com, not sure if it's still there or not.

[Zilla]

If your good with a soldering iron and know what yer doing with ciruits:
http://www.oatleyelectronics.com/kits/k140.html

They accept credit cards from NZ too :cool:

[I.R]

Dood!!!!! Awesome!!!! :D

[mird-OC]

ummm, forgive me if this is a silly question (seeing as i know little of your setup), but what's stopping you running the compressor full duty?

[I.R]

It's sooooooooooooooooooo good that it frosts right back to the compressor even under load (not good) so with the pelt I get a fairly constant temp CPU side (I'm also concerned about the temp diff between the on and off for the compressor) and the heat generated will (hopefully) prevent it frosting back to the compressor.
I'm using a floodlight as load...... the temp probe got to 65°C without any cooling.

[mird-OC]

ah i see :)

well AFAIK there is no such thing as too much cooling :D ... proper insulation/lagging should prevent the frosting. and considering the compressor would live longer if operating full duty, i'd just go full power and forget the pelt ;)

(pelts involved in any sort of high wattage cooling simply suck arse really ;))

[City_Idiot]

after spending a little time working with pelts i came to this conclusion:

They are not worth the extra money, time, space and worry for cooling they offer


*mutters about law of diminishing returns*