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Re: PSpice modeling of spark gaps



Hi Terry,


> Original Poster: Terry Fritz <terryf-at-verinet-dot-com>
> 
> At 11:24 AM 11/9/98 +1200, you wrote:
> >The real problem I see with sbreak is that the gap is not a fixed 
> >resistance but one that varies with current. What do the decrements 
> >produced with the gap model stuck in a resonant circuit look like?
> >
> >Malcolm
> >
> snip>
> >
> 
> Aaah!  Malcolm too is playing with models! :-)
> 
> I suspect that the gap resistance may be less than the cap and primary
> resistance in a well designed system.  Therefore, the resistance of the
> primary circuit may be fairly consistent throughout the firing cycle.  I
> originally came up with the 3 ohms of primary resistance by matching my
> models to the real measurements I made.  I need to go back and re-examine
> the primary resistance with my newer gaps to see what effect they are
> having on primary resistance.  My feeling now is that they are not wasting
> very much power at all.  Gary Lau is working with the zero crossing spikes
> and parasitics in the gap.  I neglected this to go for the "total picture".
>  His work is more detailed than mine in this area.  I think you can model
> the primary resistance actively in MicroSim.  I might actually have to read
> the instructions to find out how to do this however :-)).
> 
>     Terry

Actually I'm not (at the moment anyway). Just asking a question. If 
a tuned circuit with a gap doesn't have a linear decrement it isn't 
being modelled accurately, at least for the L/R ratios one typcally 
finds in a good tuned circuit. Will check for outlandish fixed 
resistance values.

Malcolm