Re: Help with making SRSG phase control work?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: FIFTYGUY@xxxxxxx 

In a message dated 1/28/06 3:06:49 PM Eastern Standard Time, 
tesla@xxxxxxxxxx writes:

>There might be some other types of sync motors in the
>size we might use for a sync rotary gap, that I am
>not aware of.  I heard there have been improvements
>is permanant magnet type sync motors.

    At my work, we've had some Sol-Syn motors for machine axis 
positioning. These are made by Superior Electric (the variac 
people!). Two sets of windings and a run cap. Many permanent magnet 
poles on the rotor. Apply DC for a brake. In fact, they could work 
just like steppers (I believe many synch motors and steppers are 
interchangeable, and Superior makes steppers as well).
    And to clear things up, I just went out and tried a 5uF cap. The 
phase controller works fine now. Motor does make a noticeably loud 
hum as the variac knob is turned up, and loses synch at the very 
highest setting (max inductance), but I can get almost a full 45 
degrees of mechanical timing out of my setup now. I'm gonna play with 
the component values and see if I can optimize it.
    BTW, that bleeder resistor across the run cap is a necessity, 
especially if the fuse blows.
    Thanks for the help, John, Scott, Ed S., et al.!

-Phil LaBudde