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Question about ultrasonic2's TEC Calculator

 Post subject: Re: Question about ultrasonic2's TEC Calculator
PostPosted: Mon Jan 10, 2011 9:56 pm 
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That really depends on where you live, I'm presuming you live in the states. In which case shipping would be a dead end, since ultrasonic lives in New Zealand. It's the one major problem with all this metal machining stuff is that the raw materials cost a lot to transport.


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 Post subject: Re: Question about ultrasonic2's TEC Calculator
PostPosted: Mon Jan 10, 2011 10:13 pm 
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flak-spammer wrote:
That really depends on where you live, I'm presuming you live in the states. In which case shipping would be a dead end, since ultrasonic lives in New Zealand. It's the one major problem with all this metal machining stuff is that the raw materials cost a lot to transport.


I actually live in the UK, so would be great deal for anyone living the UK. As far as I know, zipdogso lives in the UK.

If the delta is really 40C at 5v for a 127 couple TEC. Then I might just buy four 545W TEC's from eBay. There are alot cheaper than the high couple TEC's from customthermoelectric. However wellentech are only charging 17USD for a 50mm TEC1-28820. But they are based in china, and they only accept bank transfer.

EDIT - I have just found a CNC milling service that will cut and mill copper, and only charge £24/h. They require autocad drawing's. I have decided on using four 62mm TEC1-12730's and undervolting them to 5v. The only thing thats holding me back is the CAD drawings, and if im honest my designs are quite bad in comparision to flak-spammers and ultrasonic2's (There just basic lanes). Once I have confirmed the format that they require, would you be interested in designing the waterblock? I would pay, and can make payment through paypal.

EDIT - They have just confirmed that they need the drawing to be in either dxf or dwg format.


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 Post subject: Re: Question about ultrasonic2's TEC Calculator
PostPosted: Tue Jan 11, 2011 7:04 am 
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xtremetechuk wrote:

Thanks, I understand perfectly now.
I was just using your calculator again, and can a 127 couple TEC really have a delta of 40C at 5v when Qload=0? I have always got the impression on overclock.net, that all 127 couple TEC's at 5v would have delta of 15c-20c.


Without a link i will have to talk generally

1 it is absolutely impossible to apply 0 load to a TEC . When TEC's are rated they are done in a vacuum to achieve a 0 load. So when it's got a whacking big block of copper on it, even if insulated a load will be ebing applied to it

2 as far as i can tell the 127 at 5v will create a delta of 36 ish in my app ? not 40c

3 most people in forums quote the Tc to ambient delta not the th to tc delta. the th will be significantly higher than the air Temp due to the thermal resistance of the tim heat sink water and radiator

SO a theoretical delta of 36ish is about right but that doens't mean you will get that. In reality especially when people rate the delta from ambient it will be lower

Now for making and designing blocks i will start a new thread as it's unrelated


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 Post subject: Re: Question about ultrasonic2's TEC Calculator
PostPosted: Tue Jan 11, 2011 6:06 pm 
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Thanks.
Yes your right, I had Umax set to 38%. Should of been set to 34%. The reason I said Qload=0, was because I was just comparing the figures at different voltages, and for different TEC's.

Would you be able to make an estimate on what the delta will be for a TEC1-28820 at 12v?
Couples - 288
Umax - 35v
Imax - 20A
Qmax - 403W
DTmax - 68

According to wellentech it should be around 50C. Closest one on your TEC calculator is the 31.5v Qmax 331W. Which will have a delta of 40C at 12v. Now I would expect the TEC1-28820 at 12v to have a lower delta than 40C, because of the greater undervolt.


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 Post subject: Re: Question about ultrasonic2's TEC Calculator
PostPosted: Tue Jan 11, 2011 8:33 pm 
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xtremetechuk wrote:
Thanks.
Yes your right, I had Umax set to 38%. Should of been set to 34%. The reason I said Qload=0, was because I was just comparing the figures at different voltages, and for different TEC's.

Would you be able to make an estimate on what the delta will be for a TEC1-28820 at 12v?
Couples - 288
Umax - 35v
Imax - 20A
Qmax - 403W
DTmax - 68

According to wellentech it should be around 50C. Closest one on your TEC calculator is the 31.5v Qmax 331W. Which will have a delta of 40C at 12v. Now I would expect the TEC1-28820 at 12v to have a lower delta than 40C, because of the greater undervolt.


i must admit i can't find any charts for this TEC stating the 50C . im not saying your wrong. id just love the link to your information which might explain everything.

I dont allow people to add there own tec's to my app as the normal person doesn't understand as much as you. even if they do some manufactures rate them differently to make them seem more powerful and therefore need adjusting to be inline with the rest of the world

You got that link ?


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 Post subject: Re: Question about ultrasonic2's TEC Calculator
PostPosted: Tue Jan 11, 2011 8:51 pm 
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I had to contact wellentech directly, they have not listed any charts on there website. To be honest, I find a delta of 50C at 12v hard to believe. I'm also finding it hard to make a purchase from wellentech, I mean if there figures on delta are incorrect, what else is incorrect. Another thing that is worrying me is the quality of TEC's, and that they only accept bank transfer.


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 Post subject: Re: Question about ultrasonic2's TEC Calculator
PostPosted: Tue Jan 11, 2011 9:23 pm 
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xtremetechuk wrote:
I had to contact wellentech directly, they have not listed any charts on there website. To be honest, I find a delta of 50C at 12v hard to believe. I'm also finding it hard to make a purchase from wellentech, I mean if there figures on delta are incorrect, what else is incorrect. Another thing that is worrying me is the quality of TEC's, and that they only accept bank transfer.


im guessing when they said that they may have had the Th hotter than 27c as increasing the Th will increase the achieve able delta

Basically that TEC is the same as the CTE 400 watt TEC as far as dTmax PMAX and Qmax goes so i would expect it to perform the same. obviously the amps and voltage is different but you can convert that to the right percentage easily enough

umm bank transfer sounds like a costly pain . what do the TEC's cost ? i really struggle to buy TEC's that dont have test data with them so you can see if they are BSing you


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 Post subject: Re: Question about ultrasonic2's TEC Calculator
PostPosted: Tue Jan 11, 2011 9:37 pm 
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The TEC1-28820 costs 17USD each. But as I have said, I'm finding it hard to make a purchase from them. Thats why I have been considering the eBay 545W TEC, there still quite cheap compared to customthermoelectric, and I'm covered with paypal.

The only problem I have with the eBay 545W TEC is that four of them at 5v will require around 45A. I will be using a modded ATX powersupply, and most ATX powersupply's only have 30-35A on the 5v rail.


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 Post subject: Re: Question about ultrasonic2's TEC Calculator
PostPosted: Wed Jan 12, 2011 5:55 am 
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xtremetechuk wrote:
The TEC1-28820 costs 17USD each. But as I have said, I'm finding it hard to make a purchase from them. Thats why I have been considering the eBay 545W TEC, there still quite cheap compared to customthermoelectric, and I'm covered with paypal.

The only problem I have with the eBay 545W TEC is that four of them at 5v will require around 45A. I will be using a modded ATX powersupply, and most ATX powersupply's only have 30-35A on the 5v rail.


you do realise that the ebay 545w TEC is NOT 545watts of Qmax at 27c dont you ?

The 545 is Pmax at a th greater than 27c do a search for it on the net

The TEC is actually a 270qmax tec


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 Post subject: Re: Question about ultrasonic2's TEC Calculator
PostPosted: Wed Jan 12, 2011 7:59 am 
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Quote:
you do realise that the ebay 545w TEC is NOT 545watts of Qmax at 27c dont you ?

The 545 is Pmax at a th greater than 27c do a search for it on the net

The TEC is actually a 270qmax tec



Yes I know. I don't think I will be using them because of the amount of amperage four will require at 5v. And finding an ATX powersupply with more than 45A on the 5v rail will be difficult. If I do purchase four TEC1-28820's from wellentech and undervolt them to 12v. Would I need an ATX PSU with a single 12v rail, or will multiple rails work aswell.


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