Re: LTR Pig Project - Long Post!

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

Original poster: "Luc by way of Terry Fritz <twftesla-at-uswest-dot-net>" <ludev-at-videotron.ca>

Hi guy,

I'm a little bit on the side of the subject but your post make me think
about the
possibility of using a salt water cap for LTR cap but I know it's lousy.
From what
I know the loss are in the salt water ( resistance ) and in the glass itself
dielectric loss increasing with the frequency. Is one of you try to
estimate the
loss of salt water cap compare to polypropylene cap ... and at different
frequency...

Luc Benard


Tesla list wrote:

> 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