Re: [CAD_CAM_EDM_DRO] Pole Changing Motors?

Raymond Heckert wrote:

> Jon, I'm pretty sure that I recall seeing, some years back that "pole
> changing" motors were to be the cuting edge of motor technology. They
> actually "write" the poles in a different place, all arount the stator.
> This gives you a very precise speed control. Do a search of the major
> motor mfgrs like Leeson, Superior, Baldor, etc. I don't know why the
> technology never caught on, because it sounded like the ideal solution to
> variable speed drives. I think the units ran on 120 & 230 Vdc, with
> circuitry "writing" the poles to meet speed requirements.

Looks like you're right! I'd never heard of this before. I'm still not so
sure it is all that different than a multi-speed motor, though. Apparently,
the speed change can be done with relays (and possibly transformer
taps). You only get several speed selections, like 2, 4, 6 and 8 pole
speeds, or some combination like that.

Jon