A Kapanadze generator replication - Febuary 2013

[Grumage]

Hi Grum,

The kind of wire itself does not matter in itself, aluminium, for example works good too, and is a lot cheaper.  The bigger the insulation, the less parasitic capacitance.  The parasitic capacitance is inversely proportional to the distance between coils.  That is why a lot of tesla coil primaries are flat with widely spaced spires.   The length of the wire in the coils is very important if you want to generate standing waves, Utkin talks about it in his book. 

For the sparks, what you can do is tune the primary to 470kHz using parallel capacitors.  The sparks generator can then be finely tuned to a sub harmonic frequency, like 47kHz, or 23.5kHz.  The primary should still be vibrating strongly after 10 or 20 cycles, if the tuning is right.

Good luck!

m:o)

Hi Tika,
Many thanks for your input. Just to prove a point to myself I went shopping this afternoon and bought a length of 1mm2 Twin and earth cable, the sort used for lighting circuits. I stripped off the outer sheath and wound yet another coil. Seventyfive turns each way from center. To my horror I found that it's resonant frequency was just over 1Mhz. Right at the last gasp of my signal generator!!

The lesson!! Fewer turns means higher resonance. I honestly thought the PVC insulation would add capacitance!!

I have spent the latter part of this evening making a Bi Filar primary, and by use of series capacitors, 4 X 0.047 microfarad @ 2kv each, and a bit of coil tweeking.  I have managed to perfectly match primary and secondary coils @ 360 Khz. Tomrrow is another day the tests will have to wait!

Final question for all. In Vladimir Utkin's Secret 3.1 Quote "Best Position:   To find the best coil position, connect the signal generator to the output, and then find the coil position which shows zero at the input terminals. Alternatively, use an RLC meter connected to the input terminals and then find the coil position which gives no change in reading when the output terminals are short-circuited (for both case 1 and case 2). "
To me this makes no sense. Surely the converse will also have a zero. Please change my mind???
Cheers Grum.

PS, Sorry I missed out your earlier question. The "sparks department" is a Motorcycle ignition coil driven by a variable frequency PWM that can deliver a square wave output into a heavily inductive load.
This poses another question. Should the output of said coil be rectified? Or used as is? I rectify with 2 X 20Kv diodes.

[tika]

Final question for all. In Vladimir Utkin's Secret 3.1 Quote "Best Position:   To find the best coil position, connect the signal generator to the output, and then find the coil position which shows zero at the input terminals. Alternatively, use an RLC meter connected to the input terminals and then find the coil position which gives no change in reading when the output terminals are short-circuited (for both case 1 and case 2). "
To me this makes no sense. Surely the converse will also have a zero. Please change my mind???

I think what Utkin is saying by connecting the signal generator at the output is connect the secondary to the signal generator and find the position where the primary will be less subject to back EMF.  I remember seeing a dragonslayer video where he was explaining that the heat sinks on his transistors where there only for tuning, and that after the right position for the primary was set, the transistors would run cold.

I suggest you read the chapter on Don King's devices in Patrick Kelly's book.  There is a good deal of info for tuning the coils for your kind of setup.  And an explanation about why the exact lengths of the wires are important.  At MHz frequencies, all kind of otherwise relatively trivial matters like impedance matching become crucial, as electrical waves will bounce back in the wiring and create all kinds of nasty (and sometimes really nice) effects.

PS, Sorry I missed out your earlier question. The "sparks department" is a Motorcycle ignition coil driven by a variable frequency PWM that can deliver a square wave output into a heavily inductive load.
This poses another question. Should the output of said coil be rectified? Or used as is? I rectify with 2 X 20Kv diodes.

Why not experiment with both ?

m:o)

[Farmhand]

Hello to all,
Many thanks for your encouragement, it is most appreciated. I just wish I had some encouraging news in return!!
The pancake coil was a complete flop.This was removed in place of a more conventional cylindrical type with 10 turns. Still no output.
For zcsaba77. Yes I did make the primary movable along the length of the secondary. And many thanks for the link to The old scientist, very interesting, and I feel he is on to our joint goal!!
For Mags, Yes the windings are done in the same direction, starting from the center.
For Tika, Thanks for the info. I agree, being a Welshman, French is much easier to understand than Russian!!

For all.
I think the secret lies in :- http://www.free-energy-info.com/Utkin.htm   Secret 3. 1  THE ASYMMETRICAL TRANSFORMER BASED
ON THE SHORT-CIRCUITED COIL
The whole look screams Kapanadze.
I have a couple of questions. My coil has a resonance of approximately 470Khz, now according to the text the primary frequency should match. How do you get a spark to go that fast?
Am I right in assuming that more turns lowers the self resonant condition? Or what about a coil with more insulation (other than Enamelled ) Therefore increasing paracitic capacitance?
My conclusion is that we should perhaps look at a solid state driver. Like The old scientist is using. I feel we would have more chance of mutual resonance.
Good luck to us all, Grum.

Hi Grum, tika is correct about the resonance, if the secondary is resonant at say 360 kHz then the primary should be tuned to that as well or a bit lower because loading the secondary can usually lower it's frequency, however some ways of loading could increase it. It's good you have a function generator, makes things easier.

I find with (three coil) Tesla coils I have close coupling primary to secondary and loose coupling to the Extra coil, because of the close coupling from primary to secondary I find
the primary vibrates enough with no tuning caps, so the HV caps that I discharge into the primary are tuned so that they make the primary resonant when discharging. So I find the capacitance to make the primary resonant at the same frequency as the secondary, but rather than shunt the primary with that capacitance I use that capacitance to discharge into the primary. The close coupling of the primary to the high Q secondary keeps it vibrating in tune, the primary swings with the secondary because of coupling. I also use a tuning coil in the primary which I tap to fine tune it.

I am experimenting with other Tesla coils in close proximity to the powered coil and I find that if I shunt the primary of the added second transformer with a capacitor and a Gas Discharge tube it charges the cap and discharges the cap through the GDT which makes nice arcs from the induced coil, unfortunately the second coil cannot take the voltage and it leaks and gets racing arcs down the secondary to the primary if too much power is used.

Here's a short video clip, the smaller coil in front is the added coil with the primary shunted by the cap and GDT, I also used the tickler coil to charge a cap through a FWBR to 220 v and
allowed it to discharge by another GDT. The Bigger coil at the back is a spark gap Tesla coil of about 200 turns all up and one primary turn, res frequency is about 760 KHZ and the rotary spark gap can be run at between 250 BPS and 1600 BPS. It can use from 200 to 600 Watts. So the spark discharge frequency only need be a sub harmonic of the
resonant frequency but each setup will have it's better rates ect. Considering the transformer only has about 200 turns I think it performs OK. It sure can induce a voltage on another transformer.

The coil throwing the initial sparks is the induced one not the powered one.
http://www.youtube.com/watch?v=1rG_Rfqv6O0

Here's the powered coil itself the second video below shows some pictures of intertwining helix arcs.

http://www.youtube.com/watch?v=1nkJtrKCdFg

The arcs twist up get faster then throw themselves apart. Almost too quick to see.

http://www.youtube.com/watch?v=TxTjHk9LEwU

I can show the setup with the second induced coil and the primary GDT flashing to make it work if anyone is interested.

At this point I am just experimenting with effects and observing, trying different stuff ect.

Cheers

P.S. Forgot to mention the powered transformer has a power factor of 0.96 to 0.98. 
Main heat losses are in the 240 ballast coil which is too thin a wire with too much resistance and the spark gap.
It looses a bit of energy in the screaming banshee noise it makes as well I suppose. 

..

[Farmhand]

I'm thinking with some of this equipment I might be able to test some things out relating to Tariel's arrangements.
I'm devising a solid state circuit with IGBT's or mosfets but I can't decide exactly how I want to do it yet.

I have two of the smaller transformers that are the same, if I use them both I think it will solve the problems of the
leaks from the induced transformers.

It's kinda neat because the powered transformer excites the second transformer which has double the turns, then it
arcs back to the powered transformer or at least it tries to.

I'll make a drawing, maybe someone has idea's of how to tap the second/third transformer for some output.
The second/third transformers are simply connected to ground by the bottom of the secondaries and the primaries are
shunted with resonance caps and a gas discharge tubes of 220v, they have 400 turns in the secondary(150t)-extra coils(250t) and 10 turn primaries with 1.1 nF.

cheers

[bryanwizard]

I am doing my research on this field too. I will provide my findings as well as results in every configuration that Ive tested.