Supercomputers, fishing for information

[ethan at 757.org]

> Yes, that's how the 360's (at least mid-range) were set up.  You could tell, 
> the converter-inverter was INSANELY loud, at a massively piercing audio 
> frequency.  The key was that this one unit gave regulated AC power to all

Wild!

> We tried to get a 370/145 running at a guy's house.  That had the 17 KVA 
> motor generator set in the back (WAY more than a 145 needed, but they 
> apparently used one MG set for a range of machines).  But, he only had 60 A 
> 240V single-phase service, and we couldn't even spin up the MG set with no 
> load.  We built a static phase converter, but the imaginary current was over 
> 60 A.  Well, NO SURPRISE, if we'd just read the nameplate we would have known 
> it was a fool's errand. The 3-phase line current on the thing was about 55 A, 
> per 3-PHASE LINE, so running it off SINGLE-PHASE, the line current would HAVE 
> to be 1.7 X that much, wouldn't it?  OF course!
> We should have just scrapped the original 415 Hz power supplies and got our 
> hands on a bank of 5V supplies and adapted them.  The thing ran off +1.2 and 
> -3 V supplies at 390 A, although I think that was for the max configuration, 
> this one had minimal internal memory, so should have been less.

Ah yea, the laser show geeks IIRC would run full 200A household service 
just to get 30A 3phase off of rotary converters. A used diesel generator 
set might be another option, or if you're REALLY lucky getting 3 phase 
from the utility without paying crazy (probably only going to work if 
you're next to commercial user that already has 3ph step down already in 
place.)

Hmmm it shouldn't be that hard in this day and age to come up with that 
kind of current assuming switchers would be clean enough. I have a home 
use LED video screen I assembled/am finishing from Chinese modules that 
runs on 480 amps @ 5vdc, power supplies set me back maybe $300 or less. 
Could probably adjust them down or get similar units or higher quality 
stuff from surplus (Pioneer Magnetics, etc)


--
Ethan O'Toole