RE: synchronous motors

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>

What you want is a salient pole synchronous motor, either 1800 or 3600
RPM.  What you don't want is a hysteresis synchronous motor, as the
mechanical phase relationship will vary from turn-on to turn-on.
Unfortunately, the hysteresis vs. salient pole type is not typically
specified on the plate, and it's not obvious from the outside which type
one might be.  Hysteresis motors will have a smooth rotor of homogenous
material (see http://www.schulzemfg.com/m_syncharcter.htm), whereas
salient pole motors will have rotors similar to conventional induction
motors, with laminated construction.  No further modifications will be
necessary.

Unless you're aiming for a very high power system, I'd recommend Terry
Blake's propeller gap geometry
(http://www.tb3.com/tesla/sparkgaps/index.html), as it can use the
smallest HP motors, and is very easy to build.  Mine may be seen at
http://www.laushaus.com/tesla/sync_gap.htm.

Regards, Gary Lau
MA, USA


> Original poster: "Ethersmith" <siveya@xxxxxxxxxxxxxx>
>
> Well, on the advice of many, I am looking into building a synchronous
rotary
> gap. Locally, there is a surplus house that has many motors. Often,
some of
> these have "sync" stamped in the plate with the details. Can such a
motor
> (given a good enough match in HP and RPM) be used for a snyc gap
unmodified?
> Does it still require modification? Does it mean something entirely
> different?
>
> Thank you for your words of wisdom.
>
> --Ethersmith
>