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Re: Magnifier conversion - "best" mode?
Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>
Hi Antonio,
When I originally did this, I was not using your modes. This morning I
studied up on them. I tried a 2,3,4 mode since I think Boris said it was a
good one ;-) I used your program to find the values since I have not
figured out how to do it with the equations yet. The program is great!!!
http://hot-streamer-dot-com/temp/NewMag/0413-01.gif
This gave:
C1 = 23.8nF
L1 = 21.875uH
C2 = 85.62pF
L2 = 6.04mH
C3 = 18.5pF
L3 = 22.1mH
k = 0.4633
The peak voltage was 323kV (ideal case). It was easy to modify my present
MicroSim model for my small coil to add these values and some real good
guesses as to what the actual losses will be:
http://hot-streamer-dot-com/temp/NewMag/0413-02.gif
Happily, even with the losses (especially the streamer loading), the values
still give very good if not almost perfect C1 to C3 voltage conversion.
http://hot-streamer-dot-com/temp/NewMag/0413-03.gif
The peak voltage drops to 226 kV with loading. However, the old model only
got to 129kV!!
http://hot-streamer-dot-com/temp/NewMag/0413-04.gif
That should give 3X the power to a streamer for a brief instant!! While
the two coil system gives a lower voltage over many cycles, the magnifier
gives a much higher voltage over fewer cycles. This is a significantly
different situation with the magnifier and my explain why they are reported
to work so well!
The concerns I see in actually building one are the high L1 to L2 coupling
and the construction of C2. The coupling may be tricky, but in the small
coil case the voltages are not super high so maybe it would not be too bad.
C2 would be in a corona ring on top of the secondary and I was thinking of
having a bottom toroid on L3 to add to C2 too. However, E-Tesla6 modeling
showed that even a giant toroid (2 feet) 3 inches off the ground only gets
to 55pF. So we need a "real" capacitor for C2. I looked at the voltage:
http://hot-streamer-dot-com/temp/NewMag/0413-05.gif
90kV peak. The current:
http://hot-streamer-dot-com/temp/NewMag/0413-06.gif
11 amps peak. The spectrum:
http://hot-streamer-dot-com/temp/NewMag/0413-07.gif
160kHz and 330kHz.
These are well within the range of a series string of MMC style caps. Like
45 x 1600V 3.9nF poly caps. Those caps could withstand "accidents" due
to their self healing and one could select more or less caps for fine
tuning easily. Instead of trying to get high current we are not trying to
get high voltage. MMCs would be cheap, easy, and very hard to
damage. Door knobs and other caps would work too since the current is
reasonable, but we have so much experience with poly caps and the price is
very reasonable...
I also looked at the fist notch quench and no notch quench cases and it
appears the first notch quenching is very desirable. Better quenching, but
higher loss, gaps would do well in this situation.
http://hot-streamer-dot-com/temp/NewMag/0413-08.gif
http://hot-streamer-dot-com/temp/NewMag/0413-09.gif
So it appears that I can make the magnifier to match many of the
modes. The one I studied above and yours below all seem reasonable. Do
you have any idea if one would be better??? I could do almost any of them
so I should try to pick the "best" if there is one. With the coupling and
C2 variable, I may be able to tune multiple modes but adjusting L2 is
probably hard.
Your modes here have lower coupling and it is very easy to make C2 a higher
value but lower voltage. C2 current is certainly no problem in any case.
I need to may C3 a larger toroid since my present one is just too small for
the coil. C3 may end up about 25pF but that should not change things much.
I hope to have a magnifier and conventional coil that can be compared
directly.
Any thoughts on the "best" mode to shoot for are more than welcome!
Cheers,
Terry
At 11:10 AM 4/13/2003 -0300, you wrote:
>Tesla list wrote:
>
> > Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>
>
> > I was thinking of making an add-on to convert my small coil into a
> > magnifier system:
>
> > I would just use my present secondary coil as a tertiary coil now.
> >
> > L1 = 21.5uH
> > C1 = 23.8nF
> > L2 = 3.97mH
> > C2 = 12.3 pF
> > L3 = 22.1mH
> > C3 = 18.5pF
>
>With these values for C1, L3, and C3, the closest ideal mode that
>I find is 3:4:5, that gives:
>
>C1= 23.8000000000 nF
>L1= 19.5835714286 µH
>C2= 150.3492063492 pF
>L2= 3.0940000000 mH
>C3= 18.5000000000 pF
>L3= 22.1000000000 mH
>k12= 0.3504383220
>
>The value for L1 can be compensated by adjusting C3:
>
>C1= 23.8000000000 nF
>L1= 21.4995857143 µH
>C2= 165.0590476190 pF
>L2= 3.0940000000 mH
>C3= 20.3100000000 pF
>L3= 22.1000000000 mH
>k12= 0.3504383220
>
>But L2 if fixed by the mode and by L3:
>1:2:3: L2=18.4166666667 mH
>2:3:4: L2= 6.0429687500 mH
>3:4:5: L2= 3.0940000000 mH
>3:4:7: L2= 5.7880952381 mH
>4:5:8: L2= 3.7876464844 mH
>
>In mode 4:5:8:
>C1= 23.8000000000 nF
>L1= 21.5041500419 µH
>C2= 70.4059829060 pF
>L2= 3.7876464844 mH
>C3= 19.7700000000 pF
>L3= 22.1000000000 mH
>k12= 0.3825061606
>
>By increasing the last multiplier, keeping its parity,
>it's possible to adjust C2 to many values, ending with zero when
>it tends to infinity. The other elements tend to a limit, that
>is the magnifier with C2=0. The maximum voltage over L2 is maximum
>in this condition (~1/3 of the output in this mode).
>Your design is close to mode 6:7:infinity, but C2 is too high
>to achieve it perfectly in a lossless system. The losses in
>your model may be adjusting the tuning to a correct condition,
>however. Note that by increasing C2 and a few adjustments,
>you can change the energy transfer from 3.5 cycles (6:7:inf)
>to 2 cycles (3:4:5).
>
>What I would recommend for a magnifier desing is to first fix L3 and
>C1, then calculate L2 and the coupling from the desired mode.
>L1 can then be adjusted by adjusting C3.
>C2 and the coupling can be adjusted experimentally, by searching
>a condition that decreases the voltages over L1 and L2 to zero
>simultaneously at the first notch.
>The program mrn6 is useful to quickly visualize what happens.
>http://www.coe.ufrj.br/~acmq/programs
>
>Antonio Carlos M. de Queiroz