Re: Initial setting for sync phase angle on an RSG

To: tesla-at-pupman-dot-com
Subject: Re: Initial setting for sync phase angle on an RSG
From: "Barton B. Anderson" <tesla123-at-pacbell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Sun, 13 Feb 2000 11:36:14 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

> Original Poster: Robin Copini <rcopini-at-merlin-dot-net.au>

Robin, Terry, All,

Good question Robin. I too would expect a phase shift from the series ballast.
Right after reading your inquiry, I decided to open up PSpice. I opened my
schematics and found "motor.sch". Well, now I know why I hinted to phasing
in the
first place. I had a schematic of a variac in series w/motor and a text box
below
that said "RSG phase shift from 60Hz input" or something like that.
However, I ran
it and varied the variac inductance. Tried RC circuits in parallel and series
connections, etc... Each time I ran an analysis, I got the same results:
90 degree
phase on the voltages and 180 degree's on the currents. Changing component
values
didn't change phasing. Probes were on each side of the variac and output of
phase
shifts remained static. I'm not expert with PSpice, but this is what it's
telling
me.

I picked up my snyc rsg today and brought it home. I was going to a quickly
phase
check with a detector/emitter set up since the tungsten in the G10 is
non-magnetic,
but after I got a great signal on the scope, I realized I didn't bring the
variac
home (way to go, eh?).

Well, if anyone else with PSpice wants to give it a go, I sure would like
to hear
your results. It's a quick simple circuit. Inductor (variac), motor, and
VAC input
at 60Hz.

>
> Hi Nick, All.
>
> I have a question related to this. I too am mid - way through lining up
my srsg
> and this phase-shifting thingy has me thinking about my current limiting
> variac.
> Tell me, if I use one variac, (or none for that matter), to set up my srsg to
> fire at a particular point on the wave form, and then fire up the coil
and vary
> the current using my large variac - doesn;t this change the phase of the
> waveform coming out of the transformer on it's way to the srsg in relation to
> the waveform that the srsg motor in syncing to? (I hope this is making sense
> :-))
>
> Best Regards
>
>  Robin in OZ.
>
> p.s. my rsg variac varies voltage at the moment but I too am going to
rewire it
> to phase shift my rsg motor - just to see what happens.
>
> Tesla List wrote:
>
> > Original Poster: "Megavolt Nick" <tesla-at-fieldfamily.prontoserve.co.uk>
> >
> > Hi Bart,
> >             this came up a while ago - it Think we decided a variac *in
> > series* with the motor might be able to provide a  variable phase
shift.  As
> > I'm doing a sync rotary for alex crow I might give it a go.
> >
> > Regards
> > Nick Field
> > > Original Poster: "Barton B. Anderson" <tesla123-at-pacbell-dot-net>
> > > displacement of the drive motor via a long shaft. But, couldn't the input
> > > frequency
> > > to the drive motor be adjusted out of phase? I'll have to think about
this
> > more
> > > (just a passing thought).