I know stan talked about his bifilar chokes and how wonder it can be but the only mention on real books to bifilar I have had is that is a way to wound toroidal transformers and it give you the same inductance but this kind of winding causes you to have lower capacitance because the leads are far from each other. It's generally used in high frequency transformers or inductors and this allow you to have a higher Q
Whenever you have your secondary connected to a diode to the ground in one of its sides you will have a reference so if you pulse it in one direction you will have negative voltage otherwise you will have positive. This is how ion generators work. However I'm not connecting the tank to the ground.
Bifilar is also known as two inductors wired in parallel. But I don't think stan did it that way because of the insulation needed between turns so. You can't have 40kv between two wires is impossible it will inevitably short.
If you think a bit stan said 200 turns for the resonant coil. Why 200? with 200 turns at 40kv you have 200v between each turn (reasonable value thinking about insulation) He said 10kohms impedance so now you just need to find the right capacitor value to allow you to have a frequency where your inductance get around that. Check the calculations is not as hard as you might imagine.
Stanley described nysol insulation commonly used in litz wire for easy soldering.
I tried the ferrite toroidal core yesterday and found it to not work maybe because it saturated or maybe the losses are to much for that core. I'm rolling a very huge inductor with antenna ferrite cylindrical about 15 glued together about 6 cm long. I'm using a litz wire i made with 0,8mm wire about 12 strands. about 30 meters of wire. 1,4kg I'm using mylar between layers to insulate and to reduce the capacitance and high voltage insulation tape to fix the sides. I have about 12 or 13 turns per layer. I made like this because i found that the inductance of this iron powder and ferrite for high frequency behaves almost like an air core. Because the shape of the inductor changes the inductance values even with the same number or turns in my case. So i'm doing it to as short as possible and as fat as possible.
And i'm going to try also the iron powder toroid i got here but is quite small and i can't put many turns on it.
I would like to buy a E core that you can adjust the gap to control saturation. It costs a bit and my transformer manufacture "friend" that is already helping a lot can't give it to me for free for now.
He thinks is better to have less turns and higher permeability instead i have a strong believe from the test results and from myself that more turns and iron powder could be the solution.
You must understand that the movement of the current is independent of the direction of the turns i mean if you wrap a toroidal transformer you understand it. The current passing thru the wire pass in a circular motion thats why it induce current on the transformer. It don't flow from start to to end like would be more obvious. So it doesn't matter the direction of the wrap you can go and come back and go or wound always in one direction is your decision. Remember whenever you have the two leads close you have more interwinding capacitance Worst for high frequency.
http://www.beigebag.com/case_xfrmer_4.htmhttp://powerelectronics.com/mag/power_why_air_gap/http://electrical-riddles.com/topic.php?lang=en&cat=4&topic=189
