How to get 15v?

[Schitzo]

For a pelt, what's the best way to get 15v? I don't think there's a -3.3v, is there?

Would 3.3v and -12v work? Or just use 12v and ground and go for less than ideal performance?

[muzz]

They run best around 12v or a little more from everything I've read......... the max is 15( if a 15vpelt is what your looking at), which seems to create alot more heat for marginal gains....... I don't have alot of experience with them, but did a lot of checking up on this as I was going to try these ( and still will for the gpu).
Someone with more experience with them will give ya more info... sys and knight both have used them extensively, as have many others.

Hang in there, they'll be along.....

muzz

[Schitzo]

Heh, well hey, if they run best at 12v, even better. Sys, Knight, want to confirm?

[DisposableHero]

well its a 24v peltier.. they run the best at like 17v... the 12v pelts... well run them at 12

[Schitzo]

And if it's a 15v peltier? :p

[felix88]

don't pelts usually draw so much current that they can burn up a standard PSU?

i don't think there is a -3.3v rail, even if there is, it probably can't source much current. i believe the same goes for the -12v rail, so just be careful or you may burn something up.

[KnightElite]

If you want to run a TEC at 15V, you'll have to get a 15V dedicated power supply. The TECs actually do seem to do better at 12V than 15V, because they produce substantially more heat at 15V than at 12V (heat output increases with the square of the voltage) while not pumping much more heat accross (this is linear). So close to maximum voltage, TECs produce much more heat, which makes them harder to cool, and therefore makes them less efficient.

You'll want to make sure that your PSU can handle the current that the TEC will draw at 12V.

[Schitzo]

Interesting. Suggestions for a PSU? Or an amperage on the 12v rail I should look for?

[WesM63]

hey guys,
I'am just gettin into tec chilling, bought a maze 3-1 with 226W pelt and was wondering if a 500W raidmax PSU would work. I was told to run everything off of it. The 12V line is rated at 12V@25A, correct me if i'am wrong, but is'nt that what the meanwell psu is rated at?

[KnightElite]

Originally posted by WesM63
hey guys,
I'am just gettin into tec chilling, bought a maze 3-1 with 226W pelt and was wondering if a 500W raidmax PSU would work. I was told to run everything off of it. The 12V line is rated at 12V@25A, correct me if i'am wrong, but is'nt that what the meanwell psu is rated at?

It would work... but you would need to put a load on the 5V line as well, so it provides adequate power, and you couldn't run your computer off the power supply at the same time.

As to how much current the power supply needs to handle:
Take the maximum voltage for the TEC, and divide it by the voltage you plan to apply to it (ie. 12V / 15.8V)
take that number, and multiply it by the maximum current for the TEC (listed in the specs). That will give you the amount of current your supply needs to be able to handle.

[Dizzario]

Originally posted by KnightElite
It would work... but you would need to put a load on the 5V line as well, so it provides adequate power, and you couldn't run your computer off the power supply at the same time.

As to how much current the power supply needs to handle:
Take the maximum voltage for the TEC, and divide it by the voltage you plan to apply to it (ie. 12V / 15.8V)
take that number, and multiply it by the maximum current for the TEC (listed in the specs). That will give you the amount of current your supply needs to be able to handle.

So according to your formula, my pelt (226w) needs about 31amps... 15.2/12=1.2666666*24=30.4 Quite a bit considering its hard to even find a PS that will supply that much. Another problem would probally be that the wires that came with the pelt probally cant handle 30.4amps flowing through them. I allready melted one pair of wires testing the pelt with an antech 300w PSU that supplied only 10amps on the 12v line.

Here are the specs of my pelt:
Maximum operating temp: 125 C
Imax = 24 Amps
Qmax = 226.1 Watts
Vmax = 15.2 Volts
Delta Tmax = >67 (C)

[Nohto]

Buy a PS like I have and I think SYS bought one also.Pyramid ps 21kx (http://www.baproducts.com/pyramid.htm) 13.8v 18A constant.

[KnightElite]

Originally posted by Dizzario
So according to your formula, my pelt (226w) needs about 31amps... 15.2/12=1.2666666*24=30.4 Quite a bit considering its hard to even find a PS that will supply that much. Another problem would probally be that the wires that came with the pelt probally cant handle 30.4amps flowing through them. I allready melted one pair of wires testing the pelt with an antech 300w PSU that supplied only 10amps on the 12v line.

Here are the specs of my pelt:
Maximum operating temp: 125 C
Imax = 24 Amps
Qmax = 226.1 Watts
Vmax = 15.2 Volts
Delta Tmax = >67 (C)

No, no... you got it backwards. 12V/15.2V = 0.79
I needed = 0.79 * 24A = 18.94A. So to be safe, get a 12V 20A supply at least.

For a 226W TEC, 13.8V 18A is not enough.... you need at least a 22A supply if you plan on using 13.8V. I have an SEC1223 that does a good job at 13.8V, 23A.

[Schitzo]

Here's a silly question, but if it's a 226w TEC, and running at 15v, shouldn't it use more like 15A?

From what you said about the heat output being a function of the voltage squared, that gives the 226W... but if it's using 24A at 15v, that's 360W of power... where's the rest going?

[Nohto]

The 226w comes from the amount of heat it removes.

[KnightElite]

Originally posted by Schitzo
Here's a silly question, but if it's a 226w TEC, and running at 15v, shouldn't it use more like 15A?

From what you said about the heat output being a function of the voltage squared, that gives the 226W... but if it's using 24A at 15v, that's 360W of power... where's the rest going?

As Nohto said, it is actually consuming 15.2V * 24A = 365W of electricity, which is converted into heat. It is actually only transfering 226W from the cold side to the hot side if run at 15.2V.

If run at 12V, it will only move 12V/15.2V * 226W = 178W and consume 227W, so the TEC is actually more efficient when operated at a lower voltage (much less waste heat is generated).

[Schitzo]

So if a power supply is rated at 15A, and you try to run a 20A pelt off it, what happens?

The pelt runs at less power, or the power supply bursts into flames and kills the user?

[KnightElite]

The power supply will get very hot, since it is not meant to handle that kind of current, and eventually something inside it will fry and/or blow up. Plus the TEC won't run properly since it will not have enough current.

[Schitzo]

Alright... time to look into just a dedicated 12v DC supply. Should be easier and more elegant. Takes away all the jump-starting the PSU issues.

[Dizzario]

I was under the impression that if something required say 15v 10 amps that the lower the voltage goes the more amps it needs to preform its job, not the other way around. thats why if you have a compressor thats like 110/120v 60amps, to save power you would want to use 208/230v and about 30amps... am i wrong here? or is DC just way diffrent from AC?

Also I would like to find a powersupply that has adjustable power settings, like 15v/12v/9v. but if no one knows of one thats find, KnightElite where did you get your ps from?

[KnightElite]

Originally posted by Dizzario
I was under the impression that if something required say 15v 10 amps that the lower the voltage goes the more amps it needs to preform its job, not the other way around. thats why if you have a compressor thats like 110/120v 60amps, to save power you would want to use 208/230v and about 30amps... am i wrong here? or is DC just way diffrent from AC?

Also I would like to find a powersupply that has adjustable power settings, like 15v/12v/9v. but if no one knows of one thats find, KnightElite where did you get your ps from?

Okay.... in the example that you gave, of 115V 60A vs. 230V 30A, you will note that the power being used (voltage * current) is the same in both cases. So yes, if you want to give the same amount of power to something with a different voltage, you have to vary the current.

But, in this case, that is not what we are doing, and the current does not magically change itself so that the power output stays the same. You're thinking of a completely different problem.

Adjustable power supplies are quite a bit more expensive than single voltage power supplies, like several times as much. I got my supply at the local electronics shop, B&E Electronics.

[Dizzario]

k, thanks knight

[Tedinde]

i've got one of the pyramid 36 amp variable. about 12.5 is perfect for my 226 watt pelt. any thing more and I dont get any more gains.

And the wires to the pelt do get warm, they should be thicker with the amps that are running through them. I dont know why pelt manufactures arent worried about it??

[Marci]

Yeah, I extended my pelt cables with 2 core mains cable, and that gets incredibly hot too (226w TEC on a Meanwell S320-12 PSU tweaked to output 12.8v).

[Jasonxxx]

I have 12v 40a output on my dedicated Vicor powersupply and can adjust up to 13.2v.......But does not have active cooling, so I will wait for the meanwell to get here..

Have any of you guy seen improvement when upping the voltage from 12v to say 13.8v.......

I have a 13.8 25a Meanwell p.s. on its way.........

I'm using the swifty 462-UHT water/tec 226watt with 1/2 I.D. tygon lines with the swifty dual 676 rad with two 120mm fan blowing a total of 160cfm on the rad with a 1/2 galllon lexan res..and the swifty 300 pump......

Anyone ever use the Invotech dual 120mm Rad???? I was thinking of adding this to the system for the MCW50-T??????

[mdzcpa]

Originally posted by Jasonxxx
I have 12v 40a output on my dedicated Vicor powersupply and can adjust up to 13.2v.......But does not have active cooling, so I will wait for the meanwell to get here..

Have any of you guy seen improvement when upping the voltage from 12v to say 13.8v.......

I have a 13.8 25a Meanwell p.s. on its way.........


I have the same setup as Marci (226w TEC powered by the meanwell s320-12). It is also adjustable +/- 10%. I also find my system runs best (coolest) at about 12.8. Any higher produces zero gain as the law of diminishing returns comes into play even though the TEC is rated at 15v.

[Jasonxxx]

thanks mdzcpa,

At least I know there might be a little more cooling I squeeze out of this rig......I guess I will turn it up to around 12.8 and then work on cooling the hot side down some more, ie.. better flow and a second external rad......

anymore info or setups you have used with water/tec rigs would always help........:smileysex

As far as using the PC powersupply, thats not such a good idea.......
When I first got my tec I wanted to install it right now and not wait for the powersupply, so I plugged it into my 431watt Enermax 12v line via a molex connnector...

It worked fine for about 2weeks until I started smelling like burnt electrical wires, electronics etc.... so I looked inside my case and didn't see nothing out of the ordinary......I turn the pc off and took a flashlight to the inside of the case and to my supprise I found the molex and the wires melted to a crispy black finish!!!!!:mad:

It doesn't run any cooler on the dedicated powersupply, but at least I it won't burn up my Enermax p.s........as it was stressing it pretty hard......Susprised it didn't go up in smoke.......

So I wouldn't advise using a normal PC power supply....It just cannot handle the amperage the tec pulls.......