RE: LTR question

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

Original poster: "Pete Komen by way of Terry Fritz <twftesla-at-qwest-dot-net>" <pkomen-at-zianet-dot-com>

Hello Steve,

Resonant cap refers not to the primary tank resonant frequency but to the
60Hz (or 50Hz for the guys in the UK) HV transformer - capacitor resonant
circuit.  Thus a resonant capacitor (or strings of them) resonates with the
HV transformer at 60 Hz and, if the spark gap does not fire, can build up
very high voltages very quickly.  LTR is larger than resonant, usually 1.5
to 2 times the resonant value.  This detuning from 60Hz still gives plenty
of voltage across the caps, but prevents resonant build up.

Regards,

Pete Komen

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Saturday, October 27, 2001 8:59 AM
To: tesla-at-pupman-dot-com
Subject: LTR question

Original poster: "Steve White by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<slwhite-at-zeus.ia-dot-net>

I have been reading a lot of posts lately about LTR (lower than resonant)
capacitors. This term does not make sense to me. Any capacitor in
combination
with an inductor will form a tank circuit which will resonate at a frequency
determined by the values of the L and C. Is LTR refering to some sort of
stagger tuning where the primary tank circuit is resonant at a slightly
different frequency than the secondary tank circuit? If so, to what end? In
either case, a common suggestion that is offered to achieve this "LTR" is to
use a slightly smaller or larger capacitor than one would normally use. The
same result could be achieved by merely changing the tap position on the
primary inductor rather than going to the trouble of changing the capacitor.
Another reason often cited for using this "LTR" value of capacitance is that
it
lowers the peak voltage that the capacitor is exposed to. This does not make
sense to me either. The resonant frequency of the tank circuit should have
little effect on the voltage passing through the tank circuit. If stagger
tuning is being referred to, then there may be some rationale here. Any
insights?