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ultimate laser cooling for 20bucks?


Illuminum3415

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Peltier junctions have been around for awhile now...yeah they do work but it requires alot [and I do mean alot ] of amps to work. What it basically does is using electricity to create a temperature difference between the two sides. You can stack them as well to create a higher difference. They are really inefficient for their cost, and appear to remain as such for awhile.

If your thinking of using it on a portable laser...you might be better off installing a couple heatsinks intended for RC motors

Read up on the thermoelectric effect over at wiki.

They can be used in reverse too...read up on Radioisotope Thermoelectric Generators if you have the time.
 

billg519

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These are best used in lab-style lasers, as TEC in a handheld would draw a ton of current, reducing battery life to nearly nothing. The heatsink, as mentioned above, is the best solution in a handheld. In a labby, properly implemented TEC is an excellent feature, and is found in many commercial laser products, such as higher-output greens that run off 110/220V and IR FAP diodes. I have some of these coolers ranging from a few watts to cool a c-mount or can diode based labby, up to 100W units suitable for cooling my diode bars.
I've seen 400W units on ebay from time to time. The "Koolatron" portable cooler is based on these. http://koolatrononline.stores.yahoo.net/12v-coolers-warmers.html
 

SuicideKing

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I've used peltiers for overclocked CPU cooling. -condensation was ALWAYS a problem.
I would assume laser diodes don't like getting wet, anymore than CPU chips do.

In a handheld unit, you'd be better off with a small heatsink/fan combo, like they use on computer graphics cards:


Efficient cooling with very low current draw.
 

Cyparagon

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I suspect that rating is exaggerated. 400W at 12V is thirty three amps which would require 12 AWG leads.
 

billg519

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It probably was a little exaggerated, although the leads did look fairly hefty. On ebay, the wattage is always higher ...  :)
 

Illuminum3415

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Gazoo said:
A peltier does not require much current at all to keep a diode cool because the diode doesn't require a large peltier.
If one can create a brass square slug for the diode housing you could certainly sandwich one using 2 or 4 peltiers with the cool side facing the diode and the hot side facing out to a heatsink. A cylinders one of the worst/most difficult geometry to heatsink...being that your thermal transfer areas a tangent line in whichever orientation :-/




dunno, it may be plausible to say the 400W rating is in thermal power dissipation limit rather than power consumption

I have a 40x44 mm square Peltier thermoelectric heat pump with a temperature cutoff switch.
deltaTmax=79degC, Thot=50degC, Vmax=16.1V. 40MM x 44MM x 3.3MM. Qmax=80.6W, Imax=8.1A
Runs about $15 from allelectronics
Given that there are 125 thermocouples in the chip, I assumed each thermocouples just getting ~65ma [Imax=8.1A]
 




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