Re: tests: John Freau's SRSG Phase Controller

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <FutureT-at-aol-dot-com>

All,

I did still another test this time using a 1/10HP modified induction
motor (3600 rpm sync now).  This motor uses no start or run cap.
I used 32uF for the phase shift cap.  This seems to be the ideal
size for this motor, and gives full 90 degree phase range, with
only 5 volts of reso voltage build up.  Minimal resonance sounds
from variac.  Stays locked for full variac range.  The cap size is
quite critical for best results (stays locked with minimal reso-
voltage build up).  

Summary of cap sizes:

1/10 HP motor (modified induction)     57uF
1/20 HP sync motor                          50uF (it may tolerate smaller)
1/50 HP sync motor                          19uF (21uF may be better)

Different brands of motor and different loading conditions may
require differently sized caps of course, but this guide may be of
some help to others in selecting a cap size for a first trial.  It's
best to measure the voltage across the motor across the variac
range to make sure it doesn't build up more than 5 or 10 volts
over the line voltage.

It should be possible to select a cap size that gives just 1 or 2 volts
of reso-buildup, but so far I have not stumbled upon the exact cap
value.

John Freau