Re: LTR vs. STR for pigs was Re: PFC Question

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

Hi Shad, Steve,

Tesla list wrote:
> Original poster: Shad 
> <mailto:shenderson@xxxxxxxxxxxxxxxx><shenderson@xxxxxxxxxxxxxxxx>
>
> Hi Steve, All,
>
> Comments interspersed,
>
> On Wed, 2005-11-09 at 15:30 -0700, Tesla list wrote:
> > Original poster: Steve Conner 
> <mailto:steve@xxxxxxxxxxxx><steve@xxxxxxxxxxxx>
> >
> > Hi all,
> >
> > This debate got me thinking and I thought of a few
> > things I'd like to bring up.
> >
> > 1) What decides whether a cap is LTR or STR? The
> > answer is the leakage inductance of the transformer.
> > Now in a NST that is built in, but a pig has
> > practically none so you need to provide your own
> > external ballast. So, it is not the pig itself that
> > determines whether the cap is LTR or STR, but the
> > ballast. (And the transformer turns ratio too, I
> > suppose.)
> >
> LTR operation for a pole pig is determined by the ballast setting.  I've
> personally used an LTR cap on a pole pig, and in short, it rocks.
> Operation is very smooth, with virtually no kickback, no quenching
> problems, and very impressive operation.  Of course, it means setting
> the ballast to one point and leaving it set there, but as my ballast is
> a PITA to set, it's no big deal.
Cool! Just how LTR was it?

I've been thinking about Steve's comments. It's true, the impedance 
will be reflected by the square of the turns ratio. This will affect 
the resonant condition of equal reactances in the LC circuit. Haven't 
yet figured out if we end up with a large or small change to what we 
would condider LTR or STR. To run large LTR in a pig is not common 
place, and that was my comment. It would certainly be educational to 
work out the results. I know Richie Burnett has performed a lot of 
work in this area, but mostly for short circuit analysis.

Take care,
Bart