Re: John's sync-adjust circuit

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <ajones18-at-bellsouth-dot-net>

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

>Thanks for the report.  For an 1800 rpm motor, the mechanical phase
>shift will be 45% at the most.  But this is equal to 90 degrees of
>electrical phase shift.  For a 3600 rpm motor both the mechanical and
>electrical phase shift will be 90 degrees maximum.

I was getting 45degrees instead of the 20 - 30degrees I reported. I
saw the 45deg and it registered in my head as less. I rechecked it
this morning to make sure. So I guess it is working correctly?

>I am very surprised that such a small amount of capacitance did the
>job.  For a 1/8th HP motor, I would have expected that about 60uF
>would have been needed.  Does the motor remain locked for the full
>range of the series variac?  Or do you have to keep the variac within
>a certain range?  Is this about a 7.5A variac or so?

Yes it stays in sync the whole time. I can watch the electrodes move
when turning the variac using the strobe light. They stay steady when
I stop turning the variac. This is through the whole adjustment range
of the variac. The variac is a small one, maybe 5A don't know for
sure.

Alan
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