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Cheap tecs?

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Where can i find cheap tecs, i searched on ebay for tec and didnt find anything, i dont really want a big one like a 1inch or maybe 1/2inch would be fine hopefully under $20 but im not for sure of the price of tecs, so where would i get one for that price?


....lazer.... ;D ;D ;D
 

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okay thanks,  these things take alot of power :eek: 60 watts for a small one, i figured i could just put like a 6v lantern battery to it...


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Rhith

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If you want some decent ones 30x30mm or 40x40mm ones PM pseudo. He should still have some and they're really cheap. I have a whole handful of them from him and i'm sure you'll be happy with them :)

oh yeah and they're 0-12V DC
 
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I meant the smallest ones were 60w, Can i just hook it up to a lantern battery will that work, Or i have a 13.5v sealed lead acid battery (the kind that wont spill) from a computer power supply, will that work since it has more watts?

...lazer... ;D ;D ;D
 

Rhith

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I don't know too much about that. :-?
But all I know is I hook them up to my computer power supply and it freezes everything FAST! ;)
 

Gazoo

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You will never need to run the peltier at full power to achieve what you need. I am running mine at ~300ma's using the same circuit with the LM317 we use to power the diodes. So my labby is using 2 LM317 circuits and they run off the same power supply.

If you want to do this in a portable, a RC 7.2 or 9.6 nimh volt high capacity battery would be ideal. Or a 6 AA battery holder using nimh batterys. Do not use alkalines, nimh batteries hold up much better plus the fact they are rechargeable will save you a lot of money.
 
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I have a 9.6v ni-cd battery pack will that work, i know it wont last as long but i dont mind recharging more often then havin to go out and buy another one, Do i need a current regulating circuit for it, i dont think i will because its not really a complex comonet or do i still need one to run it off the battery?

Almost forgot, does the heatsink need to be fan cooled, i have a pretty big one i got from something its about 2 inch tall and 3inch wide 5inch long, will that be fine without using a fan on it?

Edit: i just found a 7.2v ni-cd battery pack its kinda old but i still think it works, and its 2000mah i think i might use that.

Thanks

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Rhith

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YES USE A FAN!
Don't learn the hard way like me and find that after a little while that the heat sink becomes hot enough you can cook on it!
 
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Hi,

The peltier junctions I've found to be pretty bulletproof. Keep them under max V & I and they are happy. Just remember polarity determines which side gets hot! :) You don't have to run them at max - besides, dealing with frost and condensation on your diode can be a separate issue as well. Run it at a low enough V & I to keep it cool, but not cold.

I've used TED before - you only need a heat sink as big as is necessary to keep the hot side to a reasonable temp. Depending on the duty cycle of the component you're cooling, you may not need much. You might want to use a small thermistor or something simple to trigger the cooling circuit, so it only cycles when the temp exceeds a preset value.

To give you an idea of how tough they are, a friend of mine made a beer can cooler with one- basically just a plate with some silicone grease on the cold side, and a heatsink with silicon on the hot side, running from a lantern battery. It worked! Of course, his beers never sat on the plate very long, but when they did, they stayed cold! :)

D
 

Gazoo

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You do need to regulate current because if you don't the peltier will freeze up and cause condensation which will kill your diode. Once you have your TEC built, you only want to run it a bit cooler than room temp.

You may not need a fan depending on the size of your heatsink. But Rhith is correct that a fan will help.
 
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Okay thanks i got another lm317 so i will make another circuit and use a heatsink for the lm317, maybe i can put it on the one the tec is on because it has holes for regulators,  Ill use a 5ohm resistor on the circuit, it will give about250ma to it so it  should be enough, i dont want this to form ice...that would be bad.

I need to try with this big battery too, i wonder how fast it would make ice, i have a new coolor for soda or something maybe i should buy 2 for that ;D


....lazer.... ;D ;D ;D
 

Gazoo

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I am not using a fan on mine. But get whatever you are comfortable with.... :)
 
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I might just get those ones you linked, 10 dollors for 5 good deal, i know there small but diodes wont need that much cooling for them even if i push it to like 400ma just for the fun of it, Know i need to get one from a 20x to try and get 300mw from it ;D

...lazer... ;D ;D ;D
 




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