Re: [CAD_CAM_EDM_DRO] selsyn motors

Marv Frankel wrote:

>Jon,
> I can't quite figure how a selsyn motor relates to a "control
>transformer". I sold selsyn motors back around 1947, and they were used for
>remotely controlling from one to the other. When wired correctly, you could
>turn the shaft on one, and the other shaft would turn exactly the same
>amount of rotation. The ones I sold were "war surplus", and we sold them for
>$2.00 each. We probably sold several thousand of them.
>
>

Umm, control transformer has different meanings to different people. It
can mean a plain
transformer to power control-type devices (contactors, etc.) But, in
another context, it
means something very close to the old selsyn's, but they are different,
I now realize.
A control transformer has 2 stator windings 90 degrees apart, where a
selsyn has 3
windings like a 3 phase motor. A control transformer is essentially
identical to a
resolver with one cycle per revolution. The 3-phase version is now
called a "Synchro Control
Transformer", or Synchro for short.

I bet a lot of people would love to find some of these for $20.00 each, now!

Jon