Re: 20 joules at 100 bps vs 4 joules at 500 bps

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Original poster: Steve Conner <steve@xxxxxxxxxxxx>


> Why is there such a sharp
> knee if you were to plot voltage (primary) vs spark length?


Who knows? I guess there is a certain critical field strength below 
which leaders (we agreed not to call them streamers any more) can't 
propagate. If the coil produces a fairly uniform field strength over 
most of the space it's in, then you would hit this critical field 
quite suddenly, and the sparks would leap out all at once. (and woe 
betide anyone in Steve's hot tub when it happens)

A small coil with a small toroid might produce a less uniform field, 
in which case the jump wouldn't be as sudden. The "magic field 
strength" would be achieved nearest the toroid first and then it 
would spread out as the voltage was cranked up.

I have also noticed something like it. Out of all the knobs I have to 
twiddle on all my coils, I've never seen any that has such a drastic 
effect as the voltage knob. But I have never seen it go "Bam" all at 
once in the space of 50v.

Maybe your coil is switching poles when the streamer-oops leader-no 
that doesn't sound right-discharge loading gets above a certain 
amount? A test for this would be to see if the discharge shrinks when 
turning the voltage down, at the same voltage that made it grow so 
dramatically on the way up. If it was mode hopping, I expect there 
would be hysteresis.


> then maybe you`ll explain, what is so"interestingly"

Father Dest, it's about time you built a coil for yourself, then you 
will see what is so interestingly about them ;) It's very easy to get 
caught up in trying to analyse everything. But at the end of the day 
our simulations are only as accurate as our streamer- oops leader- 
growth model, which seems not very accurate at all.

So might as well just build lots of different kinds and sizes of 
coils and see what they do. We will probably find out lots of cool 
results in the process that will help the analysis guys.

That's what I think anyway.


Steve Conner