Re: RSG adjustment

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

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

In a message dated 3/23/02 8:55:31 PM Eastern Standard Time, tesla-at-pupman-dot-com
writes:

Steve, Ralph,

Various motors of the same HP motor ratings will require vastly
different capacitance values.  But 250uF does sound high for a
1/2HP motor Steve, unless you've tested it already, and found 
the correct resonant rise and performance with that value.  I seem
to remember someone saying they needed to use 120 or 180uF
for their particular 1/2HP motor.  The motor rpm (1800 or 3600rpm),
also seems to affect the capacitor value requirements.  Generally
smaller cap values will probably cause less self breaking problems,
even with larger motors, but I'm not sure.  All the motors I've used
were 1/4HP or less.  I should really add more info at my website
about the various cap sizes and ranges needed for various motors.
So far I've used the phase shifter on five different SRSG's of
various HP ratings.  I suspect that the needed cap value may
also depend on how heavily the motor is loaded by the rotor.
I'm not sure about that either though.  The needed cap value
may depend more on the motor load than the motor rating?
The current drawn by the motor may give some clue to the
needed capacitance.

Cheers,
John


>
> > I have a 1/2 HP motor in my RSG. I am currently building the John Freau
> >  phase adjuster. I am planning on using 250 uF of capacitance. My proposed
> >  solution to the self-braking problem is to use a double-pole switch to
>
> Steve,
> I'm about where you are at with a SRSG and John's phase controller. I'm 
> wondering if you calculated the capacitance value, and if so, how? John used 
> a 1/20th HP motor for his 
> SRSG. I am also using a 1/2 HP motor and getting a good voltage rise with 60 
> uF.
> No sign of self-braking problems. The motor run caps are in multiples of 12 
> uF. I have one cap of 48 uF in parallel with 12 uF. The phase controller will
>
> also work at 48 uF so
> unless you calculated the value, 250 uF seems kinda high. Don't forget the 
> bleeder.
>
> Happy day,
> Ralph Zekelman
>
>