Re: Big Primaries, Small Caps

["Ed Phillips" <evp-at-pacbell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Tesla list wrote:
> 
> Original poster: "Malcolm Watts" <M.J.Watts-at-massey.ac.nz>
> 
> Hi Jim,
> 
> On 3 Sep 00, at 15:59, Tesla list wrote:
> 
> > Original poster: "Jim Lux" <jimlux-at-jpl.nasa.gov>
> >
> > Less stored energy in the primary = shorter sparks... The amount of energy
> > in a given "bang" is determined by the source voltage (i.e. the NST, etc)
> > and the C.  Reduce the C, and you reduce the energy.
> >
> > The basic process, from an energy flow standpoint, is:
> >
> > Wall plug
> > Transformer
> > Primary Cap
> > Primary Inductor (1/4 cycle later)
> > Secondary Inductor (same as primary)
> 
> More pedantry, sorry :(  Even at ksys = 0.6 it would take half
> a cycle to transfer all energy to the secondary. This is why
> primary loss is, or should be such an important issue in spark-
> making TCs where ksys is usually on the order of 0.25 or less.
> 
> Regards,
> malcolm


	In the "good old days" (~1905-1922) when hams were supposed to keep
their frequency above 1500 kHz, they were limited in maximum capacitor
size in order to get the resonant frequency that high, since it meant
single-turn inductors.  The solution, for those who could afford it, was
to go to higher and higher transformer voltages, up to at least 30 kV in
some cases.  The same solution is possible for TC's, but the use of
larger capacitors and lower voltages is clearly more affordable, even if
it exacerbates the modest effect of gap loss.

Ed