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Old 24-12-2014, 10:13 AM
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ZeroID (Brent)
Lost in Space ....

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Join Date: May 2010
Location: Auckland, NZ
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Quote:
Originally Posted by pmrid View Post
Brent, I'm sorry if this seems a bit pedantic but with peltiers, the process of cooling (as I understand it) is not to absorb the heat from inside the enclosure and direct it out the back. The idea, as I understand it, is that the bottom side of the peltier device gets cold and the trick is to push that cold into the enclosure via a heat sink/fan on that side. A very different process. And since the peltier produces more heat energy than cold as part of that process (because of the power/enegry used), there is more heat to be blown away by the external fan. So the internal fan, heatsink etc is always smaller in proportion to the out(hot)side one.

So my idea is to generate as much cold air as I can from the peltier and the heat sink in contact with its cold side and push that via the internal heat sink and fan onto the back of the camera.

I hope I don't have this concept wrong.

Peter
Peter,
Which ever way you look at it its all about shifting energy from one place to another. Heat is energy, BTU's. My internal heat sink is chilled by the TEC and internal air is blown across it to chill the air and thus the camera. The BTU's from the internal air being circulated is transferred by the TEC to the outside Radiator element ( inside or outside, they are both heat sinks just working in opposite phases.)
In Physics you don't say you push cold, what you are doing is removing energy thus lowering it's internal temperature.

My system works as you describe or any other way for that matter. It's just not very efficient, that is all. A cold finger or a metal to metal contact via the base plus some better insulation and a bigger heat sink inside to make the Peltier more efficient is the answer. Trying to cool down a well protected sensor inside a plastic bodied camera is never going to be an easy job. A bigger heat sink inside will allow more heat transference by the TEC and therefore a greater colder air volume to circulate. The outside radiator on that version is way oversize for the tiny inside fan and unit. Worked much better on the AS! 120. It was just that I'd already modified it to mount together for a previous version and it was easier to use.

I'll keep looking for a better enclosure after Xmas when the big electrical companies are back in action. Roll on Mk III version ...
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