Figure I can use an enermax 430W power supply for a 226 w pelt?

[Schitzo]

Should need ~20A @ 12v, which the Enermax 430 puts out on the +12. Is it gonna burst into flames on me?

[Marci]

I tried it with one here and it toasted the psu within about 20 minutes... Hiper / TTGI 550w has enough juice in it to power em tho....

[KS1]

I use an Enermax 365AX VE FMA to serve a 226W Peltier.
No problem at all!

[TheDude]

You are better off in the long run to get a dedicated supply like the meanwell.

http://www.xtwerkz.com/power_supplies.htm

:D

[Dizzario]

I just got myself a pyramid 6-15VDC Adjustable, 22amp constant, 25amps surge for $89.99. Pyramid PS-26KX (http://www.etronics.com/product.asp?stk_code=pyrps26kx)

And everyone said a variable power supply would be expensive.

[docah]

I bought a 13.8v 25 amp ps from radioshack for slightly more than you got your variable. good deal man. good deal!

[bldegle2]

the Pyramid PS are the sh.t!!!!!!!!

you can adjust the voltages up to 15v, so if your cooling is up to the task...................

BTW, the best one for us to get is the 32amp model ($118 @Ebay), the $88 22amp/26amp surge max you mentioned is the minimum you need for the 226 watter.

since I am mated to a 120mm Delta with 130CFM hammering the Pelt and heatsink, methinks i can run a few extra volts to the pelt for even better cooling.

got one on the way.

baldy:D

[KS1]

I think that higher than +12V will yield only more heat and not more cooling.

[Marci]

lol... just found an old 1970s Hornby trainset PSU... 12v DC@ 26a (x2 parallel) or 15v AC!! That's gonna get me 156w GPU Pelt thrown on it asap... it's a big grey thing with twiddly knobs on the front, full wave / half wave switch, normal / reverse switch... older than I am easily!!!

[Dizzario]

yea the 22 amp is the minimum you can use pretty much for the 226 watt pelt. but any more than that is dangerous to run through normal household electical wires. your normal house has 20 amp wires in the wall and your only supposed to use 75% of that at max. any more and you risk melting the sheething off the wire and starting a fire. im gonna try to tap into a 30 amp wire in my garage that is for a washer/dryer. It on the same wall as my computer so it shouldent be too hard. and that will be much safer than sucking 22 amps through my normal wires. plus the amount of juice im allready pulling through in that one room. 7 computers and 4 monitors plus misc things adds up...

[docah]

If the wires in your house are rated for 20 amperes then they are rated for that at 110-120v (american) to the tune of 2200-2400W of power on that circuit.

I dont mean to insult you but 13.8V @ 25A is a mere 345 watts and even if the PS is only 50% efficient that's still under 700W or 30% of the draw the line can handle. Definately not dangerous. Also proper circuit breaker rating is imperative. A "normal" breaker is 20 amps rated to protect the wiring it provides, so "meltdown" should never occur.

In your case, the number of computers in your room is rapidly approaching the max rating of the wiring. Prior to my last lan party i estimated 6 pc's/monitors per 20amp breaker was "as rated" for the wiring. In testing i've had as many as 10 per circuit, though adding the 11th caused the breaker to cave in after ~ 30 minutes of "full load"(folding or seti).

[KnightElite]

That's right. 22A @ 12V = 264W. At 115V AC, that's only a little over 2A, no danger to your breaker at all. Marci.... don't do something silly like try out AC current on your TEC :). I remember someone from hardforum did that once, and it was pretty much toast... :D.

[Dizzario]

no insult taken, i was just relaying what an electrician had told me.

One thing i would like to clear up for my understanding is: like knight said "22A @ 12V = 264W. At 115V AC, that's only a little over 2A" now are you thinking in 264w DC power or AC power (is their a diffrence?). im not sure but im guessing their is a diffrence. for my understanding it takes less DC Voltage than AC Voltage to do the same thing. so going in that understanding 22a DC is causeing the AC to pull alot more amperage than 2... Also im as i understand it its not the watts that something uses but the amps that it uses that creates the heat, am i wrong?

[Marci]

Marci.... don't do something silly like try out AC current on your TEC

Have to admit, I was tempted to try it with vidcam to hand to film the outcome... could've been fun!

Curious as to whether to trust this old psu or not... how can I torture test it to make sure it won't pack in once I have the pelt on and running? Don't have access to load testers anymore unfortunately... :(

neways, that's goin o/t... deal with it l8r...

[KnightElite]

Originally posted by Dizzario
no insult taken, i was just relaying what an electrician had told me.

One thing i would like to clear up for my understanding is: like knight said "22A @ 12V = 264W. At 115V AC, that's only a little over 2A" now are you thinking in 264w DC power or AC power (is their a diffrence?). im not sure but im guessing their is a diffrence. for my understanding it takes less DC Voltage than AC Voltage to do the same thing. so going in that understanding 22a DC is causeing the AC to pull alot more amperage than 2... Also im as i understand it its not the watts that something uses but the amps that it uses that creates the heat, am i wrong?

When we speak of 115V AC, we are actually referring to the effective, or RMS (Root Mean Square) voltage. The real voltage is a sine wave, with an amplitude of ~170V (115 * (square root of 2)).

This effective voltage is equivalent, in terms of calculations of power consumption, etc... with DC voltage.

The way a transformer works, is to take a certain AC signal, and either make it a higher voltage or a lower voltage signal. If the transformer is perfect, then the power of the signal has to stay the same on both sides of the transformer, so one side is high voltage, low current, the other side is low voltage, high current. In a real transformer, the same process applies except some energy losses occur due to heat.

Then, inside the power supply, the transformed AC current (the transformer is also in the supply) goes through some voltage regulators and filters, and comes out as DC current.

Marci: Unfortunately, I can't think of any way to test that supply out, other than running the TEC off the computer for a while with it hooked up to see if it blows up or something ;).

[KS1]

Most modern PSUs have a overcurrent/overvolt protection built-in?

[docah]

Hey KE nice full explanation of what was going on with the ac/dc there. :)


Every psu i have purchased since the one for my 386 that i started out with in 94 has turned itself off in a dead short or excessive draw situation. If you get near the borderline of the psu without engaging the protection cheaper supplies will fail you over time.

[Dizzario]

thank you everyone for clearing that up for me. grately appreciated :D

[KnightElite]

You're welcome for the AC/DC explanation. I've seen power supplies blow up in excessive draw situations, though probably anything decent will have protection of some sort, as you say.