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Re: PSpice modeling of spark gaps
Hi Bart,
> Original Poster: "Barton B. Anderson" <mopar-at-uswest-dot-net>
<snip>
> > The most amazing finding the math revealed was that Q for a
> > tuned circuit with a gap in it couldn't be quantified as a fixed
> > value the way it can if there is normal resistance only. The math
> > showed that Q climbed with voltage and absolute losses increased with
> > current. The reason for this is that Vgap is not proportional to Igap.
> > Neither voltage nor current is a fixed quantity but continuously
> > varying in normal circuit operation.
> >
> > Malcolm
>
> Yes, the gap is complex and difficult to model these details. I remember
when
> you posted your results sometime ago. It is interesting. I'm not sure I can
> grasp Vgap not being proportional to Igap. Even with varying capacitive
and/or
> inductive loading in the gap, V and I should remain proportional, unless
> there's a new physical law I don't know about. If Q climbed with voltage
then
> it appears to me the "gap" reacts capacitively in nature and the gap
> capacitance changes with volts/time as well as with varying current.
Wouldn't
> Q then follow Vgap? My thinking here is if Cgap = Igap / (dv/dt) = Q/V.
>
> Sorry I didn't reply sooner, I've been in the garage the past couple nights
> building a new spark gap.
>
> Bart
The gap discharge is an arc discharge which exhibits a negative
resistance characteristic. You won't get a linear decrement if that
isn't so. The reason Q climbs with voltage is the essentially fixed
Vgap conduction voltage becoming a smaller and smaller proportion of
total primary voltage. I could post my analysis one day if you like.
It should be in the archives from a year and a bit back. It was
labelled "Primary Q - A Brain Teaser".
Malcolm