Powering pelts (2 questions)
 

Kryotherm DRIFT-0,8
Peltier element with the following specifications:
Qmax = 172 watt
delta T = 69° C
Vmax = 24.6V
Imax = 11.3A
Dimensions = 40 x 40 x 3.4 mm
Special = silicone-sealed

I was wondering about powering the pelt with two ATX 300W PSU in serie > 24V and 10A. Any advice
tips or suggestions about this. Is there a better way ? Iwould only like to use AT(X) PSU.

If I were to use a 16V pelt, what would be the best setup?

Greetz and tnx

A better way: they to get some 24V ebays or build your own PSU.

You could use two PSU's in series. But 10A isn't much for a 11.3A pelt, it could decrease the lifespan of the ATX PSU's significantly. Besides that: you will probably get better temps when you give the pelt a lower voltage, say: 20-22V.

Using a 16V pelt the best thing is to buy a 13.8V PSU.

What about using a 350W ATX at 17V (+12V,-5V) to power the pelt ...

On PSUs the -XX voltages can only handle 1amp at most, some not even that. Your best bet is to find 2 or 3 cheap PSU and combine them or get a high dollar Power supply and use it...

You could use one 350W ATX PSU and combine the 5V, 3,3V and 12V to get a nice voltage for one pelt. You must use diodes when doing this.

The voltage the pelt will recieve is: (12 + 5 + 3,3) - (3 * 0,7) = 18,2V

I was under the impression that ATX PSU's have common ground which makes adding voltages from the same PSU pretty hard.
Please tell me im wrong.

If you use diodes it can't go wrong.

Have you actually tried this adding thing? Even with diodes I wouldn't have thought it would work, you can't just add common ground voltages. Also you forgot to take off the diode voltage drops in your calcs.

ATX PSU's have common ground outside the "box" which makes adding impossible. However if you pic the PSU apart and isolate each voltagesection it could theoreticly be done.
On most PSU's the grounds are allready connected on the pcb so in practice it's impossible .

Btw does anybody know if ATX PSU's are primary or secondary switched????

My bad :) It's AT supplies you can combine together. Course AT supplies are even cheaper than ATX...
http://www.procooling.com/articles/h..._as_one_.shtml

I think most computer supplies are primary switched.

Thanx Butcher :)

whoa, who wanted to link +3, +5, and +12 off same psu? Crazy man, crazy. =] It is virtually impossible to isolate each section of the power supply because they are usually all grounded to a single point in the supply (usually via a solder joint). It would be much easier to do what I will have posted in the next week on how to take two power supplies and run them in parallel.