Re: heat sink cooling

[Ron Schroeder <rjs@bnl.gov>]

At 08:30 AM 5/31/00 -0400, you wrote:
>Take 3 equally sized heat sinks , bare alum, one black and one white, put a
>50 ohm resistor on each and apply 12 volts. The bare aluminum heat sink will
>have the lowest thermocouple reading disproving the "black body radiator"
>theory. A black surface only helps when absorbing heat from the sun.
>
>-----Original Message-----
>From: Colin Dedman [mailto:cjd121@rsphy1.anu.edu.au]
>Sent: Tuesday, May 30, 2000 6:58 PM
>To: ev@listproc.sjsu.edu
>Subject: Re: FW: 1221B cooling (and zaprabbit stereo)

I have done the above many times.  In still air black anodizing is
noticably better.  Polished aluminum is the worst.  In moving air the color
makes very little differance but corroded bare aluminum or painted aluminum
are the worst.  Tests were done in environmental chambers to prevent
outside influences and enhance repeatability.  If bare aluminum was better,
we would use it, its cheaper.

Ron
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Ron Schroeder
WD8CDH
E. E. S.
wd8cdh@bnl.gov
rjs@bnl.gov
ron@112motors.com
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