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...