Re: Phase adjust

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

Original poster: "Jon Rosenstiel by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jonr-at-pacbell-dot-net>

Hi Ed,

I have a 1/4 Hp 1800rpm motor. With 50uF it would barely stay locked. With
100uF  I could vary the mechanical firing angle about 40 degrees. I think
even more capacitance would have been better in my case, but all I had were
two 50uF caps. I guess it's time to check out Surplus Sales!

My $.02,

Jon


> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<Esondrmn-at-aol-dot-com>
>
> John & Terry,
>
> I finally got John Freau's sync rotary phase adjuster circuit set up
today.
> I have a 1/3 H.P. motor modified to run synchronous at 3600 rpm.  This
motor
> needs 100 volts minimum to stay locked.  I used a variac that will produce
0
> to 145 volts ac and set it at 125 volts to power the circuit.  I used two
27
> ufd caps in parallel for a total of 54 ufd and mounted them right near the
> sync motor, in parallel.  These are motor run caps rated at 370 v ac.  The
> phase adjuster variac is a 10 amp powerstat which yields 0 to 250 mh in
> adjustment.  As I start to increase this variac, the motor voltage falls
> quickly and within maybe 20 % of increase, falls below 100 volts and it
blows
> the fuse, which is a 3 amp fast blow type.  I tried it again, same result.
> Do I need much larger caps with a 1/3 H.P. motor?
>
> Ed Sonderman
>
>
>