Re: Ok, what is an LTR cap.

["Barton B. Anderson" <tesla123-at-pacbell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi John, 

Tesla list wrote: 
>
> Original poster: FutureT-at-aol-dot-com 
>
> In a message dated 8/23/00 7:13:56 PM Pacific Daylight Time, tesla-at-pupman-dot-com
>
> writes: 
>
> > 
> >  Actually, PIG's are STR's (smaller than resonant). Typically, coilers use
> a 
> >  10kva, 14.4kv pig's. Resonant caps are 0.128uF (from memory). Obvisouly 
> HUGE! 
> > 
> >  We typically use smaller than resonant caps (STR's) on our systems. NST's 
> >  however (and OBIT's), can use LTR's. Could you imagine the joules for a
> pig 
> >  using an LTR? I see smoke, fire, wooosh!!! Well, for most of us, not Greg,
>
> >  Bill, Hull, etc... or you Chris (yet?). 
> > 
> >  Take care, 
> >  Bart 
>
> Bart, 
>
> I'm not so sure that Pigs use STR's.  I would say that the effect 
> of the ballast has to be included when defining a cap as STR, Reso 
> or LTR.  By adjusting the ballast to create a reso condition, the 
> power factor will be the best (at least at 120 bps) and I run my PT 
> systems that way.




I agree the ballast condition must be included to know the true power, but most
coilers run less than impedanced matched cap sizes. Because of that, even when
bringing the "actual" cap size into the same voltage and current phase, the cap
size is still smaller and the bang is smaller. So in my mind with regards to
bang size, pig's normally run smaller than resonant cap sizes. If I used a
resonant matched cap size, my coil would bang at 26 joules! Thanks to many on
the list (this is what I first was attempting) I dropped my cap size by half
and thus the joules to a practical, yet still a bang value. 

Take care, 
Bart 
>
>  At higher break-rates, this might change 
> a little in other words an STR or LTR system might give a better 
> power factor, but I really didn't do much work in that area.  Has 
> anyone looked at this or analyzed it?  I know that Richie B has 
> done some simulations of power factor at various break-rates, 
> however these may have used a fixed ballast (NST) type xfrmer. 
>
> BTW, I've run my PT system in STR, reso, and LTR modes, and 
> I've posted the results on this list in the past. The only difference 
> is that the STR and LTR modes have a very bad power factor. 
>
> Progress through innovation, knowledge, and experimentation, 
> John Freau