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Re: Coupling vs secondary voltage chart
Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
Hi Steve,
The program says that your coil should work better at k=0.18 !!
There is more power delivered to the streamer and it is delivered faster!!
I wrote a file explaining it (sort of quickly thrown together...) at:
http://drsstc.com/~terrell/modeling/WardsCoil-18vs25.pdf
The chart on page three shows the streamer energy (joules) as a function of
time. Blue is the K=0.18 case and read is the K=0.25 case. The higher K
is actually hurting the speed of the power delivery and apparently wasting
more of the coil's energy.
The delivered power to the load goes from 6.253J to 6.822J and the power is
delivered about 20 to 50uS faster. The primary currents go down a tiny bit
and the capacitor voltage goes up about 100V so not big deal
there. Primary frequency goes up a tiny bit. Secondary peak voltage is a
tiny bit lower.
If you get 72 inches now, changing the k to 0.18 might increase that to 72
x SQRT( 6.822 / 6.253 ) = 75.2 inches.
This is using the programs new "streamer power vs. time" function. It
shows the energy delivered to the streamer as a function of time.
The latest program is here:
http://drsstc.com/~terrell/modeling/ScanTesla620.ZIP
Sorry to keep updating the program all the time. But I just keep adding
new features as I want ;-)) I need to write general instructions for it
too....
Cheers,
Terry
At 12:41 PM 6/16/2005, you wrote:
Heh, thats pretty interesting that K=.25 is the peak output.
Looks like i could even back off the K to .18 or so and still probably be ok.
Its interesting to see that the graph looks smoother at the very low
K's. If these predictions are in fact meaningful, i would be curious
to see you operate your big coil from a K of say .03 to .12 or so and
see if peak performance lies at the peak in your graph there.
So i wonder what causes this difference in coupling preference, is it
the tank circuit or the secondary characteristics?
Maybe you could try a different tank impedance on your big TC, say a
.5uF cap and whatever primary it would need to tune with then and see
what K it prefers? Or maybe try my secondary specs with a .05uF tank
cap or something and the needed L to retune. That seems like it might
cover most of what DRSSTC builders might come up with... the next
thing would be to put these results to the test.
And, good work Terry!
Steve
On 6/16/05, Tesla list <tesla@xxxxxxxxxx> wrote:
> Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
>
> Hi Steve,
>
> The graph is at:
>
> http://hot-streamer.com/temp/KvsVtop-SteveWard-DRSSTC.gif
>
> It would appear your K of 0.25 is perfect! The first low K hump is there
> but far lower down for your coil.
>
> The graph of my other big coil at 140uS is at:
>
> http://hot-streamer.com/temp/KvsVtop-BigCoil-DRSSTC-140uS.gif
>
> Cheers,
>
> Terry
>
>
> At 11:00 PM 6/15/2005, you wrote:
> >Hi Terry,
> >
> >Let me just enter my values right into the text below:
> >
> >On 6/15/05, Tesla list <tesla@xxxxxxxxxx> wrote:
> > > Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
> > >
> > > Hi Steve,
> > >
> > > The model is running now at 140uS...
> >
> >Did it change the coupling vs Vsec graph? OR when you say its
> >"running" do you mean its currently crunching numbers?
> >
> > >
> > > If you send me the following data on you coil I can run it. My
coil might
> > > be substantially different than yours. The coil I modeled was
never meant
> > > to be a DRSSTC.
> > >
> > > Lprimary =14uH (though it might be 2-3uH lower)
> > > CPrimary =450nF
> > > K =.25 (this is a changing parameter, right?)
> > > Lsecondary =130mH
> > > Csecondary =38pF
> > > Streamer length =72"
> > > Rail to rail buss voltage =400V
> > > T1 on time =175uS
> > > Current limit =850A
> > > BPS =120
> > > Max coil power =1800W (might be less... the killed the kill-a-watt with
> > my SGTC! arggg!!)
> > > If the coil is on your site, which one is it?
> >
> >The DRSSTC-1
> >
> >http://www.stevehv.4hv.org/DRSSTC1.htm
> >
> >I look forward to what your program spits out ;-).
> >
> >Steve
>
>
>