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Re: gEDA-user: Exposed copper -- still need to make a pad?
On Sep 27, 2007, at 10:41 AM, Larry Doolittle wrote:
>
> OTOH, your radiator has to get quite hot to carry away much
> heat by infrared radiation. Presumably you have some airflow,
> either passive (convection) or active (fan-driven). Then you
> want exposed metal, and its emissivity doesn't matter much.
You'd be surprised at how much gets carried away by radiation. For
things like resistors, 2X derating relative to natural convection is
generally sufficient in a vacuum. But if you calculate the thermal
resistance of a thin plastic film over metal, you'll find it's
negligible.
John Doty Noqsi Aerospace, Ltd.
http://www.noqsi.com/
jpd@noqsi.com
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