Re: Streamer length vs. power delivery time...

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Ward <steve.ward@xxxxxxxxx>

Hi Terry,


> I wrote up a little blurb comparing my DRSSTC and Steve's.  It would appear
> that the power delivery time is pretty critical:
>
> http://drsstc.com/~terrell/modeling/StreamerTime.pdf

More to think about now.

But there is one big detail that doesnt make sense.  That being, my
bang energy *cant* be that small!  When i do a pspice simulation of my
coil, i get the following energies per shot for the given cycles of
operation:

Primary Cycles	/ Streamer Energy
6	/ 8.7
6.5	/ 9.6
7	/ 10.6
7.5	/ 11.6
8	/ 12.6
8.5	/ 13.5
9	/ 14.5
9.5	/ 15.4
10	/ 16.4
10.5	/ 17.3
11	/ 18.2

The text didnt paste too nicely, but i think you can figure it out.
To figure out the energy per shot, i just did the integral of the
power through the streamer resistance: s(W(Rstreamer)) is what i used
for pspice to do its math.  Is this a valid method?  When i integrate
all of the energies in the tank circuit (including the losses) i end
up with almost exactly the same energy that is in the streamer (which
it should be).

Im running 9-10 cycles right now which suggests ~15J, which agrees
with the fact that i was slowly blowing 15A fuses when operating on a
120V line at 120bps.  The large filter capacitors explain why the 15A
fuses are going.  Pspice says the line current would be 23ARMS in the
case of 15J shots at 120bps, but i only modeled the line with .2ohms
of resistance, while it might be higher, and i didnt try to figure in
the inductance since its just 60hz.  Im not sure how much current is
needed for a fuse to blow out slowly (these are just standard "speed"
fuses, not slow blow or anything).

Anyway, assuming 15J/shot, that would exactly match the spark length=
1.7 SQRT(bang energy X 120).

So why does ScanTesla suggest im only running 6-7J per shot??


>
> I suppose we could pull the old coil data bases with a zillion coils
> reported in it and actually try to find the function...  That would be the
> Freau equation's constant for streamer length vs. power delivery time...  A
> bit of a time consuming project but if we had about 20 data points, maybe
> the line would be straight ;-)

Hah, good luck!

>
> Perhaps we should define a new "term" to describe "power delivery time" and
> define it better.  Like the time it takes to deliver 90% of the bang 
energy...
>
> Lets NOT use the term the Marx generator folks use :o))

Yeah, "rise time" is not the best term here.  I cant think of a better
term though...

Steve

>
> Cheers,
>
>          Terry
>
>
>