Speed and phase servo control of motor (was Cliff's notes)

From:  FutureT [SMTP:FutureT-at-aol-dot-com]
Sent:  Sunday, January 25, 1998 10:02 AM
To:  tesla-at-pupman-dot-com
Subject:  Re: Speed and phase servo control of motor (was Cliff's notes)

In a message dated 98-01-25 00:36:04 EST, you write:

<< Thanks for the info, John. It's snowing again in Ohio and time to make
> things in the lab! I probably used a wrong term by saying dwell. what I
> am trying to construct is a 20 degree adjustment on the fixed gaps on
> the outer ring. (Adjustable along the radius of the rotor.)


By coincidence, it's snowing here too, but I'm in a lazy coiling mood.
Suppose you need more than a 20 degree range?  The caps may
achieve a peak charge about 90 degrees offset from the input
voltage.  Since you're adjusting the speed of your motor
electronically, perhaps you can adjust the phase electronically also?
(like the head drum in a VCR).  This would make any mechanical 
adjustments unnecessary.  This feature was what first stirred my
interest in the electronic method...no mechanical phase adj. 
capability needed, if electronic phase control is used.  makes it
easy to adjust the phase while the coil is running without getting

If your speed control circuit uses some sort of feedback to adjust
the speed, then by variably delaying that feedback you should be
able to adjust the phase.

John Freau