Re: SRSG phase control? (and now also size of motor)

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

Original poster: "Kent Vander Velden by way of Terry Fritz <twftesla-at-uswest-dot-net>" <graphix-at-iastate.edu>


>See:   http://hometown.aol-dot-com/futuret/page3.html
>
>Only a variac, capacitor, a fuse, and a resistor are needed.
>In some cases where a cap-run motor is used, only a variac is 
>needed.  
>
>John Freau

  Wow, this is great help!  Perhaps a naive question, but will the
"optimal" mechanical position of the sync gap change over time
(ignoring mechanical drift, etc.) or can a sync gap be set once
mechanically and forgotten?  What if the gap is moved to a different
circuit (e.g. different neighborhood) or there the load on the current
circuit changes, perhaps as other inductive loads are changed?

  It was not completely clear how the capacitor is chosen however.
Do you just try various caps and compare the voltage difference across
the motor?

  Also, I noticed that you are using 1/20 HP motor for your gap, but
other people recommend more like 1/4HP.  Is this difference because
yours is a true sync motor and the minimal suggestion of 1/4HP is for a
motor modified for salient pole operation?  I guess I am looking for 
some reassurance that a 1/6HP is fine or if I should go ahead and
use a spare 1/4 or 1/3HP.

  Thanks.

---
Kent Vander Velden
kent-at-iastate.edu