Re: LTR Pig Project - Long Post!

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Tesla729-at-cs-dot-com>

In a message dated 2/16/01 2:18:07 PM Pacific Standard Time, tesla-at-pupman-dot-com 
writes:

< The ballast setting is what determines if it's LTR or not >>>
< anyway in a pig coil.  I don't really see the term LTR as having >>
< real meaning with pig coils.  One just adjusts the ballast for >>
< best results with a given cap size.  But if one does use the >>
< reso-calcs for a pig, the actual input power should be used, not >>
< the pig's rated power, unless they happen to be the same.  >>>>>

John, Kurt, Shad,all,
I have to agree with John on this issue. One matter to consider
with the smaller (NST or OBIT) coils is that you need to squeeze
out every possible inch of spark from the available power source.
With pole pig systems, as John stated, the resonant size is more
determined by the external ballasting than the nameplate rating of
the transformer. Remember, a non-current limited distribution trans-
former can put out many times its nameplate rating for a limited du-
ty cycle and this amount of output is basically only limited by its
percent impedance rating (maximum short circuit amperes from the
output). The bottom line is no one living in a normal residnetial dwel-
ling is going to be able to exceed the short-term capacity of even a
5 kVA pole pig from their in-house electrical service.

My pig driven Tesla system is powered by a 10 kVA pole pig which I
rarely push beyond 8 to 9 kVA due to space limitations. If you do the
math, the reso-sized cap for exactly 10 kVA from a 14,400 volt trans-
former (~ 695 mA) should be around 0.128 uFD. However, my cap is
0.0825 uFD, so, I too, am running the typical STR cap with my pig 
system. Keep in mind that I am also running in the 300 to 350 bps
range, which is considerably faster than the synch 120 bps, which is
the frequency rate that the "resonant" condition is based on in the first
place. Obviously, a truely resonant cap size would be smaller at 350
bps than at 120 bps, assuming all other factors remain the same. And,
as John said, since pole pigs are designed to be able to withstand 
voltage transients much higher than their rated voltage, it is advanta-
geous to utilize the high transient voltage conditions obtained from 
resonant and smaller than resonant caps to obtain maximum output 
potential.

All in all, it would be really interesting to see what kind of results 
could be achieved by building a sync rotary pole pig system using
a truely LTR primary cap, though. I think the $ cost limitations of
such a mammoth-sized capacitor keep a lot of the ametuers from 
exploring this avenue (myself included). Maybe someone who isn't
as monetarily challenged as myself could pioneer some research
into this area ;-)

Keeping 'em Sparkin' in Memphis,
David Rieben