Re: LTR Pig Project - Long Post!

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

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-uswest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<FutureT-at-aol-dot-com>
> 
> In a message dated 2/17/01 4:27:35 PM Eastern Standard Time, tesla-at-pupman-dot-com
> writes:
> 
> > Hi John,
> >
> >  At 02:52 PM 2/16/2001 -0700, you wrote:
> >  snip...
> >  > I would
> >  >say that one does not want to run a large degree of LTR in a pig
> >  >because you want a high voltage for better primary efficiency, and
> >  >you want to keep the power factor good.
> >
> >  LTR coils should still fire at the full rated transformer voltage.  You
> >  basically just keep loading up capacitance until you can't charge
anymore C
> >  to the full firing voltage.
> 
> Terry, all,
> 
> I agree that the LTR coil will still fire at the rated xfrmer voltage, but
> I think a smaller cap may fire at a higher than rated xfrmer voltage
> because of resonant charging that can occur at certain ballast
> settings.  This higher voltage should help to improve the tank
> efficiency provided that too much xfrmer saturation does not occur
> due to the over-volting.  

1. The firing voltage is a function of the gap, not how it is excited.

2. Because of resonance, with a "matched capacitor" the voltage can be
higher than the name plate value. If the gap is set too wide (firing
voltage too high) the possibility of insulation breakdown becomes very
real and, I suspect, is the cause of many NST failures.  It has been for
me when I got greedy and opened up the gap to get longer sparks.  Once I
thought about it and set the gap so it would just fire at rated voltage,
haven't lost any more transformers (knock on wood).

Ed