Did you mean 'series' instead of 'parallel'?

If you run the two TEC's in parallel, the voltage applied to each TEC will be the full output of the supply. (Neglecting voltage drop in the hookup wires.) If the TEC''s are hooked up in series, the output of the supply will be divided between them, but not necessarily equally.

For rough power requirement calculations you can calculate a resistance for the TEC. It won't be that accurate, but a 20% margin on the supply's current rating will cover the error for normal applications.

So, just dividing Vmax/Imax...

R226 = 15.2 / 24 = 0.633 Ohms
R80 = 16.1 / 8 = 2.01 Ohms

If these two TEC's are connected in series across a 24V supply, the voltage across the 80 Watt TEC would be:

V80 = 24V * 2.01 / (2.01 + 0.633) = 18.25 Volts

V226 = 24V - 18.25 Volts = 5.75 Volts

So you would have much too high a voltage across the 80 Watt TEC, and much too low a voltage across the 226 Watt TEC.

Oops. Thanks for the check Since87. Parallel applies same voltage to both TECs. Series divides the voltage (unevenly as you note) between the two TECs.

Last I remember, the 172W pelt wasn't able to keep the high-end CPUs cool. I apologize if I'm wrong (an unfortunately well practiced action).

TY Since87 for clearing that up


You dont think 172 will be enough then?

Well, what should I do then?

Well, you could buy a big (to handle high power) 24VAC transformer to downconvert the AC voltage, convert to ripply DC with a bridge rectifier, then filter it with a big cap to get a your DC for the peltiers.

I think there have been several people that did that on the ProCooling boards.

:confused: :confused: WHAT??:confused: :confused:

Long time ago, but it may have been a project on one of the other cooling websites.

Anyway, the idea is that you are getting an unregulated linear power supply. Regulation isn't needed since your load really doesn't vary that much.

Yo-Duh87 has some experience here. But the http://www.epanorama.net/links/psu_linear.html website has some stuff too.

wow Thats awesome. Way to confusing for me, but very interesting none the less...

I have decided. I think.

To get that 24v meanwell PSU
Get a 172 watt 24v Pelt and underpower it

Get 80watt pelt for GPU
power it with my Vantec Stealth 420


Sounds okay?

1 thing.. So they sell more powerful potted pelts @ 24v 12A? like 200+?

It would be best that you learn to figure out for yourself what you should do, but...

1. Get a Meanwell or equivalent 12V supply and use it to power a 226 Watt TEC.

2. If you've got a PSU rated for 25 Amps or more on the 12V rail, get a 172 Watt (24V) TEC and run it from the 12V rail of your PSU. (A 172 Watt TEC running at 12V will cool a tad better, and draw less current than an 80 Watt TEC running at 12V.)

3. If your PSU is rated for less than 25 Amps on the 12V rail, buy this or something equivalent, and use it to power a 172 Watt TEC. (Or 80 Watt to save some money.) There are multiples of these with a buy it now price of $17.99. I don't know anything about the brand, but they are spec'd at 80% efficiency which is pretty good for such a supply. At that price it's worth taking a chance on IMO.
Of course, if the supply fails, it will be your GPU that gets toasted.

Taking your advice. Im going to get that PSU for my GPU and that 24v Meanwell for CPU

But 1 last question..

Would it be better to go the route above

or

Just get an

ENERMAX EG465P-VE(FM). 460W Power supply for AMD K7, K8
12v @ 33 A

Meanwell does make a good power supply, but that's not an answer to your question.

As for answering your question... I think you need to do the old two column trick. Write the reasons to choose one alternative in the first column and the reasons to choose the other alternative in the second column. Step two: pick your best column.

I think we have given you enough criteria to start adding reasons to choose the enermax or meanwell.

Besides, when all is said and done, even a failure isn't really bad. You learned something from it and can share that with the rest of us. So, you see? You can't lose.

As for the article on powering pelts, look here: http://www.overclockers.com/tips1054/. Yo-DUH_87 was kind enough to find that when I talked to him. Thanks Yo-DUH_87!

Yeah, but not a whole lot. At the end of my Pro/Geeks! article I hinted at my using high-power transformers for my application, but that was the extent of it. I realy haven't moved too much further in the project due to time/money constraints.

However, JoeC at overclockers did an article on building a pelt supply here. I will be doing something similar for my project ;)

Edit: Ya beat me brians ;)

Aw i would do that, if i wasnt so elctrically challenged lol

Well I did a chart, I think Ill go for Enermax now, and eventually a Meanwell later on, Enermax now though :)

http://24.92.200.72/mods/enermax%5Fv%5Fmeanwell.jpg

forgive me if someone already said this, im kinda in a rush and didnt read all of the posts but here goes....
a pc power supply wont work for the pelt, regardless if it says that it puts out 25 amps because its divided amongst the different voltages leads and they generally rate it peak power not nominal power. i ran my 266 watt pelt on a 400 watt atx psu and it would only give me 11.95 volts @ 16-18 amps nothing more. I use the meanwell S-320-12 which is adjustable from i think 9volts up to 15.5 volts and im running right around 13volts. That power supply you SHOULD be able to find for 80 bucks if you take some time to look around
i got mine for 80 on the button including shipping (70 and 10 for shipping)
good luck
Steve-O
:drool:

Well, it depends upon the ATX power supply. You need to read the amperage supported on the +12V rail and ignore the other rails. So, if a 400W PSU says it gives 25A on the +12V line, you're OK powering a pelt that requires 11.93A (or whatever specs you need).

Well I was going for the...

226 Watt pelt @ 24A
and
80 Watt pelt @ 8A

which is 32A

The enermax I was looking at is 12v @ 33A

So with the pelts dropped down from the 15v to 12v the amps will drop down too. so this should work out fine right?

Yes. Assuming Enermax didn't lie. :D

:p lol yes