Definitely the way to go!
L4 extra coil inside rim, connected to L3 secondary inside rim.
L4 grounded on the outside rim.
L3 parallel tuned with 21nF
L2 series tuned with 115nF
Fres=113.56kc/s (near 8th subharmonic of L4=112kc/s)
PSU: 2x19.1Vdc x0.67A dc =26.6W input power
L2 impulse is 387nS
L4 ring is 896kc/s and L4 half wave is 608ns
scr240.png =L2 impulse in yellow (half wave measurement)
"241"=L4 ring orange, full wave measurement
"242"=L4 half wave orange measurement
243=overview, with current probe (green) on L3 inside rim
244= L4 ring double period measurement
245= L2 impulse (yellow) and L3/L4, see how the polarity matches! (impulse is too fast)
So by connecting this way, the L3 L4 and L2 impulse are all phase alligned. no need for flipping L4 over, to get the phase right.
I also measured full power, at around 65W input, then the current of L3 was high around 14A pp.
I then measured L3 on the outside rim, and current there was even higher, 16A pp, while the voltage was much lower (?)
I think I should be able to create a perfect sine wave on l3/L3 inside rim, If the impulse is matched to the L4 ripple, and if L3 has te right subharmonic of L4.
I could slow down the impulse, but I can better decrease the L4 windings, to speed it up.
In the end, I should rebuild the coils (now cast in epoxy) with the knowledge I have.
L1 should remain fast, for high voltage impulses, but slow enough to prevent ringing (which occured with unifilar coil, impulse 180ns)
L4 could also be made unifilar, to speed it up, but probably much to fast. better to decrease windings.
I wonder how this behaves under load.
And I haven't tested L4 current, but I expect it to be in phase again. which is interesting as that would be connected to earth ground
Very happy with these results, as L4 high voltage (low capacity) now combines with L3 high current (large capacity parallel).
So voltage and current are joined together, L4 is feeding L3
SCR240.PNG
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SCR241.PNG
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SCR242.PNG
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SCR243.PNG
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SCR244.PNG
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SCR245.PNG
- 37.04 kB, 1280x824, viewed 28 times.