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Re: Coupling vs secondary voltage chart



Original poster: Kurt Schraner <k.schraner@xxxxxxxxxxx>

Hi Terry,

might it be, the high voltage secondary maximum at low coupling of k=0.035 could just be at the condition of "critical coupling", when the frequency response spectrum is just showing _one_ maximum, instead of the higher coupling 2 ? Just a thought (didn't check by calc's.). Anyway: great simulations and graphs :-).

Best regards, Kurt

Tesla list schrieb:
Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
Hi Steve,
At 02:54 PM 6/15/2005, you wrote:

This seems to go against your idea that low K would somehow be better,
doesnt it?

This was a conventional coil case. In the DRSSTC case, the strange low K hump appears. I ran the DRSSTC case and it is at K=0.035:
http://hot-streamer.com/temp/KvsVtop-BigCoil-DRSSTC.gif
This is the same thing but run with a DRSSTC limited to 500 amps and 12.5J/bang. The current limit was never a factor, but you can see the joule limit kicking in at k=0.72. It looks like the DRSSTC is pretty immune to coupling other than the rise time Jimmy tells us we need to get good sparks.
This one took 1,960,000 models and 4.6 hours to run since I was searching a very wide parameter space deeply for the squirmy DRSSTC.
The run parameters were:
=================
ScanTesla-Special V-6.10 June 14, 2005 Terry Fritz
C1 2.770000e-008 2.770000e-008 1.000000e-009
R1 5.000000e-001 5.000000e-001 1.000000e-001
L1 5.000000e-005 2.500000e-004 1.000000e-007
L2 7.540000e-002 7.540000e-002 5.000000e-003
K12 1.000000e-002 9.900000e-001 1.000000e-003
R2 3.910000e+002 3.910000e+002 1.000000e+000
C2 4.420000e-011 4.420000e-011 1.000000e-012
C3 3.830000e-012 3.830000e-012 1.000000e-012
R3 2.200000e+005 2.200000e+005 1.000000e+003
T1 0.000000e+000 1.000000e-003 -1.000000e-007
Vrail 3.400000e+002
VCpri_init 0.000000e+000
DwellTime 0.300000e-003
Current_Limit 5.000000e+002
BangEnergy_Limit 1.250000e+001
Goal Type 0
=================


I think the rate at which the voltage is changing on the toroid is
more important than the overall voltage.  Low K should take a long
time to build up, despite that it may build to a higher voltage.  I
think overall the sparks will be shorter =\.

Yes! Probably very true! But it appears one does not have to risk racing arcs for performance. If K=0.25 or 0.18 the performance is probably "about the same". Fascinating that the DRSSTC seems to be so "flat line" for output voltage. The rough line seems to be the little bouncing off peaks and such as the K is varying. T1 was 300uS.
I should point out that the load capacitance was still "fixed" at (3.83pF) which might not have been a good assumption per Malcolm....


I am awaiting your experimental tests/results on all of this!

With all these cool computer models, who needs "real" data!! :o)))))
BTW - The latest version of ScanTesla just has the (output current bug fixed from 6.00) is at:
http://drsstc.com/~terrell/modeling/ScanTesla610.zip
The "special" version I made these charts with is really hacked up... I hope to clean it up better before "admitting" to it ;-))
I also did a power analysis check with the program and it was correct within 0.014%, so the program must be doing something right ;-))
Cheers,
Terry



Steve

On 6/15/05, Tesla list <tesla@xxxxxxxxxx> wrote:
> Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
>
> Hi All,
>
> I set ScanTesla to find out how coupling affects top voltage.
>
> I used the data from my big coil:
>
> http://hot-streamer.com/TeslaCoils/MyCoils/BigCoil/BigCoil.htm
>
> The coupling ran from 0.01 to 0.99 in 0.001 steps. The load was 3.83pF
> calculated from the initial primary cap energy (21kV 28nF) using the Freau
> formula.
>
> The primary coil was tuned to maximum top voltage at each coupling level to
> within 0.1uH. I cut the fluff out of a special optimized version of the
> program so it could do 1000+ models/second! 441000 calculations (400
> seconds - 1,200,000,000,000 machine cycles!) later... Here is the graph:
>
> http://hot-streamer.com/temp/KvsVtop-BigCoil.gif
>
>
> Cheers,
>
> Terry