RE: Gap Current/Voltage Waveforms

>Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
>Hi All,
>I have posted a LONG gif image of a bunch of voltage and current graphs of
>my rotary gap with no primary in place at:
>	Terry

Hi Terry:

What a wealth of information those traces convey!  I have a few questions
and observations.

On the gap voltage traces, following firing, the voltage seems to settle
towards a non-zero level opposite in polarity from prior to the bang.  Is
this just a DC offset problem with your probe?

Just following the start of gap conduction are at least two modes of
oscillations on top of the tank resonance, no doubt due to parasitic L's and
C's in the tank.  What I find surprising is that most of them occur only
following the initial conduction.  In some previous scope traces that you
published, major VHF oscillations were re-excited following each zero
current crossing, but in these new traces, there is relatively minor
activity at these crossings.  I was about to suggest that the difference may
be due to single vs. multiple gaps, but the earlier experiments were done
with a single gap, and your latest traces were done with a 2-gap RSG and
probably comparable in quenching behavior.  In both cases, no secondary was
present.  It would be significant if it were possible to eliminate these
parasitic oscillations by choice of gap and primary geometry's.  Is this
what is happening, or is this a measurement artifact?

Gary Lau
Waltham, MA USA