Power Supplies

[GoldMember]

I need someway to power my 172w peltier.. I need to give it atleast 17vdc at no less then 11.5amps

I don't want to give it the full 24vdc though.. or get a 24vdc PSU that I can't adjust down to a lower voltage.. unless I can't find this.. then I guess I have to use a 24vdc setup..


I've looked at some Antec PSU's.. like the 510w one.. and it sounds like it might do it


IF ANYONE CAN HELP ME! PLEASE DO SO!

 

[Superdoopercooper]

I can help. There are a few different things you can do.

1) <very non optimal> Ok... at 11.5amps, you need to go from 24 volts down to 17.5V. So, 6.5V/11.5A = ~0.5Ohm. Therefore, if you had a 1/2 OHM power resistor, you could set that in there to drop the voltage... asssuming that the 11.5amps is fairly constant. You'd have a (11.5)^2*0.5 Watt = 65Watt space heater, though.

2) A few power diodes could drop your voltage. Put.7-10 power diodes in series... and that would drop you about 5V - 7V. This is a constant drop (more or less) with current... unlike solution one which varies liniearly with current. Problem here is that each diode would have to be P = I * V... 11.5amps * 1V (probabably more like 0.5 V, but for arguments sake)... 11.5W didoes. That is hefty. So, if you have 6 of those, you are looking at the same wattage as above. But, the more I think about it, no matter what you do (solution 1, 2, or 3), you'll be needing some heatsinks anyway.

3) Build your own regulator. More effort (especially at the current that you require), but can be done. We'll go that avenue if solution 2 is way out of the question. The 11.5 amps is kinda killer.

If you want more help than this, let me know.

 

[GoldMember]

172W DRIFT 0.8 Potted

Imax = 11.3 Amps

Qmax = 172 Watts (Uses 221 Watts.. That is what the Distro of this Peltier told me)

Vmax = 24.6 Volts

Delta Tmax = 69 (C)

Size = 40mm X 40mm X 3.2mm

"I finally got my 172 watt peltier from TE Distributing. The dimensions are 40x40x3.3mm, so it's nice & easy to insulate compared to the bigger 48 or 50mm ones. However, the downside is that you will need a dedicated PSU (ATX need not apply) to run it due to the voltage requirements. I'm running the 172w with 18v from a switchmode PSU - higher voltages offered no cooling improvements for me at all"
http://www.overclockers.com/tips326/

"172w TE Distributing peltier, 11.4A @ 24v - currently running with 18v from a dedicated switch mode PSU mounted inside the tower. Higher voltages offered no improvement in CPU temp, as the water temp seemed to increase proportionately to the peltier temp decrease." http://www.overclockers.com/tips326/


As you can see.. 24vdc is completely useless.. as he is using the EXACT same Peltier as me from the same distributor.

I would REALLY like to use a power supply to power the peltier as I want a 2nd PSU. The one I have now is only a 300w and I wanted another PSU to power the peltier, light switches, 120mm radiator fan.. Plus probably the CD-rw and CD-rom. That way the 300w I have only has to do the mobo/cpu and 2 hard drives..

Plus all of my switches and stuff are set for a 2nd PSU.. which I burnt out trying to get 17vdc to the peltier.. see.. I took my 2nd 300w PSU which is rated, +12v @ 10amp and -5v @ 0.5amp..

Put the +12v line on the red line coming from the peltier and the white line on the black line coming from the peltier.. My PSU ran this for about 1 minute.. then the fuse went.. now when I turn it on all I hear is this little spark inside .. but no power.

I really want to use a 2nd PS.. I found like.. 510 Watt Antec which is http://www.antec-inc.com/product/powers/pp510d_spe.html

Or.. something that will power this fricken Peltier at ATLEAST 17v @ 11.3amps.. I would like 18v or even 19v.. NO HIGHER then 20v..

So as you can see.. I would like to do this through a 2nd PSU somehow.. I was looking at this 24vdc Power Supply on eBay that I could get for 30 bux.. it would work PERFECT.. but I won't be able to power any of my PC parts with it.. and I would need to re-rig my switches for it.. my ON/OFF switches.. Before I had my 2nd 300w PSU hooked up with 1 switch for power on .. 1 switch for the 120mm fan, 1 switch for the lights.. my switches have 12vdc LED's in them.. so I had one switch to control the lights.. to turn them on and off.. it's a nice setup.. maybe a little half ass'd backwards.. but it worked.. and I was running the Peltier at +12vdc and using the black grounding wire as.. a grounding wire. . I'm surprised I didn't burn me CPU UP! Seeing as +12vdc just isn't enough power to fricken cool it.. well it was getting +12vdc @ 10amp!! Maybe if I supply it with +12vdc at 15amp or greater? I don't know.. so now you know what I want to do and how I would like it to be.. oh, and I don't want to spend a gazillion dollars on getting this monster PSU! I would like to spend no more then 80.00.. seeing as I can get this 24vdc @ 16amp PSU on eBay for only 30+ shipping..

 

[blahblah99]

With all the money, effort, and time your going to spend on getting the extra 100Mhz, why not just go out and buy a fast cpu and be done with it?


If your that ambitious, I would just design my own power supply for that peltier since it isn't too picky about voltages and 17Vdc @ 12A isn't common. Just buy a transformer, power rectifier, and some caps. Hook that power up to a relay to your main psu on the computer and walla.

Or do what superdooper said and step the 24vdc down to 17. The easiest way would be to use a power transistor and a zener to regulate the voltage across the base/emitter. 24V into the collector, a power resistor from collector to base, and a zener from base to gnd. An 18V zener will give u ~17.3V out at the emitter.

 

[GoldMember]

I'm pulling 300mhz.. I guess I will just go with the 24vdc power supply I saw.. From now on i'll use only 156w Peltiers.. they hook right up to a 12v line on the PS..

 

[Soulkeeper]

i just went down to an old used electronics store (kinda like a thrift store) and picked up a good 24v benchtop power supply
it works great to power my two pelts

 

[GoldMember]

how much?

 

[Soulkeeper]

yeah i run two of these

Imax = 7.9 Amps

Qmax = 120 Watts

Vmax = 24.6 Volts

Delta Tmax = 69 (C)

Size = 40mm X 40mm X 3.4mm


cause they were out of the model you got
just find any kind of power supply that can supply enough amps at the proper voltage (overkill is nice heh)
i think mine pumps out like 25 or 30 amps

 

[Superdoopercooper]

I feel really stupid....

What is a "peltier"?

 

[GoldMember]

TEC more like it..

ThermoElectric Coupler.. It's called the Peltier effect.. one side get's really hot.. the other cold. Just do a search for

Peltier on google.. You'll get a wealth of information.

I was just set-up today with a 24vdc @ 12amp Power supply.. cost me 25 dollars and it also scales down to lower voltages.