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Re: Coupling vs secondary voltage chart



Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

Hi Kurt,

On 16 Jun 2005, at 18:57, Tesla list wrote:

> 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 :-).

Unless the Q of the coils is particularly low even k=0.035 would be
much higher than that needed for critical coupling. One system I took
to critical coupling required elevating the secondary more than 3
feet above the primary. Also, power transfer is getting pretty lossy
at critical coupling as the inherent coil losses become significant.
The possible voltage maximum would be less at critical coupling
because of these losses. Consider: an ideal (lossless) transformer is
always depicted with k = 1.

Malcolm


> 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
>
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