Peltier Amperage at 5V

[ChiefScout]

Hey what kinda amperage do you guys think that I'd see if I ran a pelt at 5v instead of 12v. The one that I've been thinking about buying is like a ......160W i think, anyways it draws bout 4.5 amps....I was wondering how much it would draw at 5v. Would temps drop a lot?

Thanks,
Chief

[Sophisticated]

well seems u lowering it to less the half the volts then my guess would be that it will cool less then half of it full power

[{PMS}fishy]

VA=W assuming 100% efficancy.

12*4.5=60w You sure its 160w?

5*4.5=22.5w

Assuming that Im working with the proper numbers.

22.5/60 = 37.5% of the inital cooling capability.

If thats really 22.5w its totally use less for anything.

[Sophisticated]

as i said in simple terms lol

[Prandtl]

Originally posted by {PMS}fishy
VA=W assuming 100% efficancy.

12*4.5=60w You sure its 160w?

5*4.5=22.5w

Assuming that Im working with the proper numbers.

22.5/60 = 37.5% of the inital cooling capability.

If thats really 22.5w its totally use less for anything.

If you lower your voltage, your amperage will go down too. If you put half the volatge, you can expect to have a little under half the initial amperage at full volt. so in this case,

(5/12)*4.5 = 1.875A
so you really only have around 10W

[ChiefScout]

Ok thanks for the info, I just wasn't too sure how less it would be. Would running a pelt rated at 12V at 5V be almost completly useless? I plan on running a couple pelts at 5V to cool down my water resevoir. The hotsides will be passively cooled and the hot air will be vented up and sucked out of my tower. You guys think I would see any change in temps at all?

thanks a ton,
Chief

[{PMS}fishy]

Originally posted by Prandtl


If you lower your voltage, your amperage will go down too. If you put half the volatge, you can expect to have a little under half the initial amperage at full volt. so in this case,

(5/12)*4.5 = 1.875A
so you really only have around 10W

Do me a favor and check your math again. Why are you dividing 5 by 12?

[{PMS}fishy]

Originally posted by Sophisticated
as i said in simple terms lol

You just guessed. 30% and a little less than half is quite a big difference if you ask me. I showed him how to work it out too. So if in the future he wants to caculate things like this he does not have to ask everytime.

[Prandtl]

Originally posted by {PMS}fishy
Do me a favor and check your math again. Why are you dividing 5 by 12?
ever done any electronic before? Ever use V=RI, Ohm's law? The only constant in Ohm's law is R, the resistance. Since you know both V and I @ 12V you can calculate R wich is

R = V/I = 12/4.5 = 2.666667 ohm

so for V=5

I = V/R = 5/2.7 = 1.88A, or

V1/I1 = V2/I2 where 1 and 2 are suffix with V1=12V and V2=5V

I2 = (V2/V1)*I1 = (5/12)*4.5 = 1.88A

any better? Of course that is an overestimate of I2 since a peltier isn't exactly a pure resistor, but that's a good enough estimate.
A more acurate value can be calculated with:
(1-(1-V2/V1)^0.877)I1 = I2 (with this formula you get I2=1.7A)
I took this formula from a file Since87 post in another thread. I think his source was a technical paper from Marlow Industries.

[ChiefScout]

Thanks a ton for the math guys, I've asked my physics teacher but he said that electronics is the next unit, Ass. Anyway thats a big help guys. Yah I did have the reated watts for the peltier wrong earlier.

I'm going to go for a 600mhz FSB....I was gonna try with a 1700XP....but I lost the bid on the perfect stepping while I was at work....lame.

Anyways thanks a ton,
Chief

[AudiMan]

Originally posted by ChiefScout
I'm going to go for a 600mhz FSB....

:eek: :eek:

What's the record for high FSB on an AMD-XP anyway?

[{PMS}fishy]

Good luck finding any MB that will go that fast.

I think the fastest I have seen was around 270mhz

[squeakygeek]

Originally posted by ChiefScout
Thanks a ton for the math guys, I've asked my physics teacher but he said that electronics is the next unit, Ass. Anyway thats a big help guys. Yah I did have the reated watts for the peltier wrong earlier.

I'm going to go for a 600mhz FSB....I was gonna try with a 1700XP....but I lost the bid on the perfect stepping while I was at work....lame.

Anyways thanks a ton,
Chief

By 600mhz FSB I assume you mean 300mhz FSB?

[ChiefScout]

yah exactly. Highest I've seen is at 272, and that was done on the DFI board I want to buy. I think if I'm able to perform some crazy ass volt mods...then it could be done. Maybe I'll bust some japanese out crazy style and try and contact hipro5.....guy that hit 1600FSB on P4.

I tried to find the record for an athlon xp...yet couldnt....darn google...you have finally failed me.....that or my searching skills yet again. lol

[{PMS}fishy]

If you are refering to FSB then refer to it by FSB, not memory bus. You are going to confuse people that way.

600mhz is the memory bus of an AMD running at 300mhz FSB. There is a huge difference. Please be aware of this.

[ChiefScout]

ok i'm not retarted....I plan on running the bus at 600mhz....300mhz is no feat at all....i mean cmon now.

Anyone know the xp fsb record?

[squeakygeek]

Originally posted by ChiefScout
ok i'm not retarted....I plan on running the bus at 600mhz....300mhz is no feat at all....i mean cmon now.

Anyone know the xp fsb record?

You're not retarded, but you don't know what you're talking about. 300 FSB is what you mean.

edit: and you're not going to get that high, either.

[zabomb4163]

Originally posted by ChiefScout
ok i'm not retarted....I plan on running the bus at 600mhz....300mhz is no feat at all....i mean cmon now.

Anyone know the xp fsb record?

http://www.xtremesystems.org/forums/showthread.php?s=&threadid=30966&highlight=fsb%2A

291MHz = DFI Lan Party B 2-17 by Lastviking (Winbond-BH5)

and here are your mods
http://www.xtremesystems.org/forums/showthread.php?postid=325645#post325645


-no, you will not stand a chance at the record unless you have some serious ram.
if you do not currently own bh5 or bh5...
http://www.newegg.com/app/ViewProductDesc.asp?description=20-146-283&depa=0 its one of the last places you can buy it.

[ChiefScout]

Thanks for the links man, and thanks for acknowleding that its POSSIBLE....rather than just shutting me down. I could only do it with BH-5....why not push OCZ EL PC4200....that wouldnt be much of an overclock at all.

We've got to encourage our fellow members....in the short time i've actually been a member, i've been slammed and flammed several times.....i've seen this happen to other members too.....

cmon now people we're a community of people with some general common practices and thoughts....now lets act like we should.

[{PMS}fishy]

Well Adata will do 300fsb 1:1

I really doubt that you will get anywhere near that speed though.

The guys at XS will do anything for 1mhz more. They really are extreme.

On of the members Hipro5 has something like 20 mods on his IC7 that hits 400mhz FSB. Talk about fast.

[ChiefScout]

yah hipro5 is uber leet. Still I think I'll hit 300mhz on amd, and if I dont i'll keep trying. Thanks for the support though...lol

[zabomb4163]

Originally posted by ChiefScout
Thanks for the links man, and thanks for acknowleding that its POSSIBLE....rather than just shutting me down. I could only do it with BH-5....why not push OCZ EL PC4200....that wouldnt be much of an overclock at all.

We've got to encourage our fellow members....in the short time i've actually been a member, i've been slammed and flammed several times.....i've seen this happen to other members too.....

cmon now people we're a community of people with some general common practices and thoughts....now lets act like we should.

i still dont think you understand how difficult it is. to pull off 300fsb you will need a very good motherboard, very good memory, very good processor, and very good power supply


motherboard - currently holds the record. should do 250fsb easily.
http://www.newegg.com/app/ViewProductDesc.asp?description=13-136-137&depa=0

memory - GEIL pc4200 for top fsb overall and buffered memory test. mushkin pc3200 222special for all real world benchmarks
http://www.newegg.com/app/ViewProductDesc.asp?description=20-146-287&depa=1

power supply - regardless of the brand you will NEED adjustable rails.

Fortron 530watt
http://www.newegg.com/app/ViewProductDesc.asp?description=17-104-968&depa=1

Antec 550watt true control
http://www.newegg.com/app/ViewProductDesc.asp?description=17-103-922&depa=1

[squeakygeek]

Originally posted by ChiefScout
Thanks for the links man, and thanks for acknowleding that its POSSIBLE....rather than just shutting me down. I could only do it with BH-5....why not push OCZ EL PC4200....that wouldnt be much of an overclock at all.

We've got to encourage our fellow members....in the short time i've actually been a member, i've been slammed and flammed several times.....i've seen this happen to other members too.....

cmon now people we're a community of people with some general common practices and thoughts....now lets act like we should.

Nobody has flamed you, shut you down, or otherwise disrespected you. We have said that you won't be able to do it, but feel free to prove us wrong. How much money are you planning on spending on this 300mhz project?

[ChiefScout]

uhhhhh actually yah i have been flamed a couple times, not in this section though. When posting about what is better for the highest overclock an amd athlon XP 1700 or 1800 ppl called me stupid for even wanting to use a T-Bred.....GO MOBILE

I dont know...i figure a couple volt mods, some hella ram, some pelts...its gonna be an ongoing project.

[squeakygeek]

Originally posted by ChiefScout
uhhhhh actually yah i have been flamed a couple times, not in this section though. When posting about what is better for the highest overclock an amd athlon XP 1700 or 1800 ppl called me stupid for even wanting to use a T-Bred.....GO MOBILE

I dont know...i figure a couple volt mods, some hella ram, some pelts...its gonna be an ongoing project.

uhhhhh actually no, neither myself or others follow you around in other threads and watch what other people say about you, so don't complain about being flamed in this thread unless someone has flamed you in this thread.

[ChiefScout]

Originally posted by ChiefScout
in the short time i've actually been a member, i've been slammed and flammed several times.....i've seen this happen to other members too.....


Did I say in this post or forum? no.