IBM 4331 Mainframe

Jon Elson elson at
Mon May 1 10:39:54 CDT 2017

On 04/30/2017 11:38 PM, Guy Sotomayor Jr via cctalk wrote:
> Just to let folks know that I finally moved the IBM 4331 Mainframe this past weekend
> from where it was currently stored to my shop.  Pictures are here:
> <>
WOW, looking at those photos gave me goosebumps!

Hmm, depends what actually needs the 3-phase power.  There 
are home-made and commercial rotary phase converters.  Great 
for motors, but you need to work on them carefully to make 
sure they are balanced well enough for electronic loads.  
The motor loads help balance it better, but the electronic 
loads cause the generated leg to sag.


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