Powering 2x120W 24.6V DRIFT-1.15 Peltiers

[Brent]

I'm new to peltier overclocking so please bear with me....

I recently bought a Enermax 550W ATX PSU, I've heard it is only capable of delivering 12V but I've also heard there is a way to hook up two PSU together (I have an extra 300W ATX PSU) in order to get the needed 24V.

I've seen several how-to's on this subject, but none mentioned how to do so in such a way that both PSUs were able to be turned on at the same time through the power on button.

Also, I was wondering if it would be okay if I used the 550W PSU to power my motherboard and fans for the radiator (I'm using the low-flow restriction radiator from DangerDen that you can fit 3 93mm fans across) as well as one of 120W pelts, and the 300W PSU to power the other 120W pelt (or will the voltage/watts automatically be shared between the two when they are wired together?).

Help would be greatly appreciated.

[jackyfu]

I asked the similar question "How to turn on/off 2+ ATX PSUs at the same time ??" in the other forums... I got no reponses ...


I did some experiments.. It didn't work out well..

1. plug the 1st ATX PSU to your M/B
2. connect the [power good], [power on sw], and [ground] 3 signals from you M/B's ATX power connector to the 2nd ATX PSU

You should be able to find the signal's definitions of the ATX power connector from your M/B's mannual. My A7V133's mannual has it.

I had some weird problems... I can turn both of the ATX PSUs ON..
When I tried to turn them off, only the 1st PSU can be turned off. The 2nd PSU was still on... Damn ! It's so weird...

Do you want to try on yours ?
Let me know if it works !!

[resago]

Assuming you get the power supplys in series correctly, you would only have as many amps @24v as the 300W PS could provide.(roughly)

[jastrckl]

I haven't tested it, but I think all it takes to get both PSU's to fire up together is to tie the green power good wires together. Of course, one of those will still have to also plug into the motherboard. Alternatively, you can tie that wire to ground, and it will work like an AT supply, and fire up whenever the switch is on. I have a couple of supplies lying around that I've been messing with, but one is AT, so I can't help you too much with that. As far as wiring them in series goes, that's easy, just make sure that there is a load on the +5V rail on each supply, and that only _one_ of the PSU's has a connection from common ground to chassis ground, or else the supplies will likely zap each other. ondaedg has a nice writeup on how to remove the chassis ground for wiring up supplies in series/parallel. While all these are fun excercises, for peltiers with as high ratings as you are using, you really should use a separate independant power supply that strictly puts out 12VDC or so. Ham radio supplies and car battery chargers are good places to look for high current DC supplies.

[Ebola]

jastrckl is correct ...

By shorting the green (pwr on) to any black (ground), you will be able to power up an ATX power supply.

The way I did this (to avoid cutting up my main Power Supply) was to install a 12 volt relay in my baybus. By connecting a standard pc molex connector to the relay switch, I can attach that to any lead off of the main PS. I then opened up my second power supply and desodered all the connections (with the exception of the green and a black wire) from the motherboard connector. I then attached a Radio Shack 2-pin connector to the green/black wires coming out of the 2nd PS and the other half to the relay switch.

So, the series of events will proceed as follows.
1. You hit the power button on your pc.
2. Your main ps powers up.
3. The 12 volts on the main ps closes the relay switch (which shorts the grn/blk on the 2nd PS).
4. The second PS starts up.

If I'm not mistaken, they have a nice write up at virtualhideout.net on how to do this. Unfortunately, I have been unable to connect to them for the last 2 days to verify.