360/50 microcode listing

Jon Elson elson at pico-systems.com
Thu May 7 20:53:45 CDT 2015

On 05/07/2015 12:41 PM, Paul Koning wrote:
>> On May 7, 2015, at 1:16 PM, Jon Elson <elson at pico-systems.com> wrote:
>> ...
>> You can't do that with a real 360 (some 360/20's were pretty small), even a 360/30 was a pretty big box.  And, you can't run a 360 off normal residential power, either.  Many of the peripherals used 3-phase motors, and hacking the converter/inverter to run off single phase would not be a task for any but the most experienced EE.
> That isn’t really true; hasn’t been for a long time, and even less so in recent decades.  Home machinery operators have used “phase converters” for ages to drive machinery like lathes that use three-phase motors.  A rotary converter is basically just a three-phase motor modified to run from one phase power across one of its windings — it delivers the three phases at the three winding terminals.  And nowadays you can get a “variable frequency motor drive” which is in effect a three-phase AC power generator, frequency of your choice within reason.  The smaller ones run off one-phase power.  Either option starts at just a few hundred dollars, and rotary converters can be built from an old three phase motor plus a capacitor or two for much less than that.
Well, first, rotary converters draw a LOT of imaginary power 
(in other words, they have an awful power factor) and so the 
line current can become MUCH higher than you would expect.  
Also, the 360 series converter inverters were REALLY 
sensitive to line disturbances.  Yes, the MOTOR load in the 
peripherals could be run off a phase converter or a VFD.  
I'm not completely convinced the CPU and controllers, etc. 
would like phase converters.  And, running them off a VFD 
would likely be disastrous, as these put out 400 V square waves.

We tried to rig up a phase converter scheme to run the 
motor-generator set on a 370/145 in a guy's house, and it 
did NOT go well.  he only had a 60 A 240 V service, and the 
imaginary current was over 60 A!


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