Re: Monitor Problems

["Steven N. Hirsch" <shirsch@adelphia.net>]

Michael J. Mahon wrote:
>> I have a bit of a wierd fascination with power supplies, which I guess
>> is kind of like the oily hand brigades fascination with cubic inches.
>> You mentioned a while back some experience with an ECL machine - while
>> fairly harmless, I'm sure the power supply for such system would be
>> really a sight to behold (at least those of us who are fascinated by
>> banks of capacitors) :-)
> 
> True.  A large ECL machine demands low voltage at very high current.
> The prototype I mentioned had a couple of 500A power supplies at 3.7v
> (or something like that).  They were high frequency switching supplies,
> but since the current was so high the filter capacitors were also huge--
> like 100,000uF (or .1F  ;-).  The power supplies were about 20% of the
> volume of the machine.  I was really impressed by the bus bars that
> delivered the power--about 1" x 3/8"!

A number of my coworkers at Big Blue were with the mainframe development
organization in Poughkeepsie, NY during the heyday of bipolar systems.
Besides the requirements for water-cooling (TCM - Thermal Conduction
Module in IBM-speak), a typical CPU board dissipated > 2.5 KW!  The
power supplies on these babies were AC --> DC rotary converters driven
from 440VAC 3-Phase.  Nothing so mundane as power transformers,
rectifiers or switching power supplies.

Ah, the good old days...

Steve