29 Dec
2001
29 Dec
'01
4:04 p.m.
If you consider 65f to 145f heat shocking significant
then whatever
you do don't turn on your PC. Seriously, that is not enough temp
change and cycles, common temp shock testing {operating} is
freezing water to 158F water {+70C} for many (usually hundreds
of cycles). Usually the upper temp is not the operational limit but,
the storage limit (in the 150C {300f} range!). Never minding what
wave soldering a 16pin dip does in a room temp to molten solder
step!
The key is TIME. 65F to 145F is not that big of a jump, but when it
happens in about a second - well, that is a pretty good rate of change.
dT/dt and all of that stuff I don't remember how to do anymore.
When I turn my machine on, certainly some parts go from room temp to
something pretty hot. It, however, is a nice smooth, slow climb. The
processor probably gets hot really fast, but I am sure the designers had
that in mind for such a power hog. What about the other chips that never
use that much juice to get hot? I am sure they do not appreciate such a
sudden rise in temperature.
William Donzelli
aw288(a)osfn.org