Re: sync, phase, LTR-ness

["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 3/30/02 2:17:06 PM Eastern Standard Time, tesla-at-pupman-dot-com
writes:


>
> Hi John:
>
> Your report about the "normal" vs. "atypical" modes of sync gap operation
> got me thinking.  I never actually scop'ed the "atypical" waveform before
> and your report that the voltage always reverses before firing in this mode
> makes sense, and is consistent with the observed high current draw!  At the
> peak cap voltage before the reversal, there is substantial energy in the
> cap, but the gap is not yet aligned to fire.  So the cap voltage reverses
> and passes through zero.  At the zero crossing, the energy that was in the
> cap, plus a bit more from the ride down, is now stored in the magnetic
> field of the NST.  But NST cores weren't designed to store energy like
> this, so the core (shunts?) saturate, and this results in the observed high
> current draw.  Funny how this seems to be coming up a lot lately?



Hi Gary, all,

Yeah, I didn't actually measure the current on the TT-32, but
I'm assuming it's probably high in the atypical mode based on
prior work and the work of others, and the theory, etc. 

>
> Let's think up some more descriptive names for these modes.  I'm at a loss
> for something short that describes this without resorting to some new
> acronyms.  "Normal" vs. "Firing After Voltage Reversal with Core
> Saturation" or "FAVRCS"?  Yuk!



Well maybe NF mode for normal firing mode, or NP mode for normal
phase mode, or just N mode for normal mode.  Maybe the core 
saturation can be understood to happen without being included in the
abreviation.  You're sure to hear from Ralph telling you that 
none of these are acronyms.  VR mode would be a
possibility for Voltage Reversal mode.  It would be understood
that the firing would occur after reversal.  When this is discussed 
it could be called the LTR-VR mode, or LTR-N mode, etc.  At
least to begin a discussion, after which it would be refered to
simply as N mode or VR mode.  It could even be refered to as
the "R" mode, for "reversal" mode, as in LTR-R mode, to contrast
with LTR-N mode

In another issue, it's been stated on the list that a 2nd notch
quench may actually be better than a 1st notch quench, because
the extra energy surge at the second pri/secondary transfer may
help grow the sparks.  I wonder though if there's any real 
evidence for this?  I wonder because it's so hard to separate
quench, coupling, and gap loss issues.  It would be nice to
devise a test to settle this question once and for all, any ideas?

Cheers,
John