Re: Bulk Order 15kW SSTC Boards - Heatsinks Room Temperature

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: dhmccauley-at-spacecatlighting-dot-com 

Yes, I do see that point.  If you had a device say running at 120degC and
hooked to a heatsink at 22 degC (which is impossible anyways since there
will be a heatrise on the heatsink) and room temperature was also at 22
degC, there would be no heatflow between the heatsink and the surrounding
air.  This is the infamous technique of using a heatsink inside a completely
sealed small enclosure.  Once the environment reaches steady state, the
heatsink and surrounding air reach the same temperature and the benefits of
a heatsink are nullified.

However, my statement was stemming from the fact of a chilled liquid cooled
heatsink.  The device may be dissipating significant heat, but in a liquid
cooled heatsink (or cold plate), you can easily
maintain that heatsink (cold plate) at room temperature and still remove any
heat dissipation (above room temperature) through the internal liquid
interface.

Dan



 > I think Ken's problem with the concept of a 'room temperature heatsink'
 > stems from the physical impossibility of dissipating heat from an object
 > which is at the same temperature as it's surroundings.
 >
 >
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Thursday, September 25, 2003 7:09 PM
 > Subject: RE: Bulk Order 15kW SSTC Boards - Heatsinks Room Temperature
 >
 >
 >  > Original poster: "Mccauley, Daniel H" <daniel.h.mccauley-at-lmco-dot-com>
 >  >
 >  > Thats completely wrong.  My heatsinks on my power circuits for my SSTCs
 >  > now utilizing fan cooling run just slightly above
 >  > room temperature at about 80degC.  A liquid cooling system built with a
 >  > homemade chiller (which can be just a tank of ice for low budget
 >  > experiements and many coils of tubing) can easily get down to 15-20degC
 >  > cold plate temperature.  Of course, a more elaborate system would be
 >  > required for longer running times.  You sir, are purely mistaken in
what
 >  > is achievable with a little thought.  Power electronics utilizing
 >  > heatsinks maintaining room temperature are not only a reality, they are
 >  > simple to implement.
 >  >
 >  > Dan
 >  >
 >  >
 >  >  > Room temperature heatsink power elctronics? It's too bad
 >  >  > things here are
 >  >  > now marketing hype first, facts second.
 >  >  >
 >  >  > KEN
 >  >  >
 >  >  >
 >  >  >
 >  >
 >
 >
 >
 >
 >