28 Jan
2014
28 Jan
'14
7:02 a.m.
On Monday (01/27/2014 at 12:33PM -0500), Paul Koning wrote:
On Jan 27, 2014, at 11:43 AM, allison <ajp166 at verizon.net> wrote:
or, the ETA10, where we just dumped the whole thing in a tank of liquid
nitrogen.
The same design ran with a 14 to 20nS clock cycle air cooled but when
immersed in LN2, ran at 7nS clock. This was in the early 80's.
There were over 300 "ALSI 20K" CMOS devices, 380-some pins each, on the
42-layer PCB, which was entirely submerged in the liquid.
Chris
--
Chris Elmquist
...
I've run gear below freezing and as long as there was no condensation
things
went well. Condensation is bad so if you bring gear in thats cold allow
it to warm
and not collect moisture. The spec for most DEC gear explicitly says no
condensation.
Pretty much everything from anywhere says that; with the possible exception of military
grade electronics.
An extreme example is seen in CDC mainframes, which are cooled by cold bars in the
chassis through which refrigerant runs. Those require tightly controlled humidity,
because the chassis is colder than room temperature.