Re: nonresonant cap = imcomplete charge ?

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 10/21/02 1:53:47 PM Eastern Daylight Time, tesla-at-pupman-dot-com
writes:


>
> >but I've heard that (or maybe misunderstood) a GTR cap (as above xfmr
> >req 27.5, tank is greater than 27.5, say 35nf)....
> >so I've heard that a GTR cap is not as efficient as a resonant cap.
> >it was stated that less energy is stored than a resonant cap.



Larry,

An interesting thing about resonant sized caps, is that this
seems to be the only type that can cause an unmodified NST to
draw more than its rated power without using a step-up type variac.
This may not be true in all cases however.
However there's more danger of NST failure with a resonant
value cap.  More robust non-shunted types of transformers can run
successfully with resonant sized cap value.  Of course
in these cases, resonant value is determined by the external
ballast setting, rather than by the transformer characteristics.

A disadvantage of resonant operation with a typical primary
circuit ballast is that it steps up the transformer primary 
voltage and can cause saturation and poor efficiency.  
Ballasting the secondary for resonant systems is therefore
preferable, but is rarely done. 

In general, an LTR cap in an NST system can provide a 
reasonable bang size because although the voltage is lower,
the uF value is larger which compensates to a degree.

John