19 Jun
2014
19 Jun
'14
8:04 a.m.
Those are rotary converters, and when built correctly
they have excellent phase balance. Some of the articles discuss in detail how to achieve
that. Basicallly, those are rotary transformers, very similar to the old ?dynamotor?
power supplies found in WW2 era military radio gear. Think of it as a motor and
generator, merged together.
This type of rotary converter and a dynamotor are a bit different. In
the rotary converter, the motor and generator portions "share" the
windings, but in a dynamotor, the windings are isolated but wound
together. Dynamotors typically put out DC.
One does not ever want to have a dynamotor rewound.
You can buy them commercially at machinery supply
companies, but the DIY kind you describe are essentially the same thing and can be much
cheaper if you can find the motor component cheaply.
The problem is that single phase motors bigger than 3 HP are difficult
to find, and tend to be very expensive.
I would think for any DEC gear, except for a KL10, a small rotary
converter is fine. I have seen a couple of computer collectors with
big iron run machines in their houses with a rotary unit.
Me - well, I cut to the chase and bought a building with decent three
phase service.
--
Will