Re: Stack of flat coils (was 8 kHz Tesla Coil)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Peter Terren" <pterren@xxxxxxxxxxxx>

I have all the bits to make up a TC based on a stack of flat coils. I 
have the spacers, wire and acrylic base and oil tank to put it in.  I 
am aiming for 600 turns of heavy PVC coated wire in a one foot high 
coil.  I am aiming for a record coil to spark length ratio with a 
target of 4 foot sparks to give a 4:1 ratio.  The winding of heavy 
gauge wire in a single spiral will be a challenge.
http://tesladownunder.com/Tesla_coils_intro.htm#Multilayer%20Tesla%20coil

Peter


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Tuesday, September 20, 2005 2:52 AM
Subject: Re: 8 kHz Tesla Coil


> Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>
>
> Hi Boris,
>
> Multilayer will have breakdown limitations which I know you've 
> already considered. Did you have some thoughts about this as far as 
> a specific winding technique? It will still have the same RF loss 
> issues, regardless.
>
> I think it was Antonio who mentioned a stack of flat coils. This 
> would be interesting to look at. The distance between each flat coil 
> would need to be separated enough to prevent coil to coil breakdown. 
> Winding direction, id to od connection, all would be important to 
> keep the stacks as compressed as possible to take advantage of the 
> proximity (that would be the hard part).
>
> I wound one flat coil a couple years ago. Pretty easy to do. I used 
> a lazy Susan turn table, layed down double sided carpet tape onto a 
> sheet of plexy, and started winding (round and round and round). The 
> tape helped keep the wire in place as the work went on. It would be 
> very interesting to wind several identical flat coils maybe only a 
> 10" o.d. to keep the volts between stacks somewhat low. Flat coils 
> do have a tendency to arc along the surface when over stressed.
>
> Using a 1x10 (id & od) with #24 is 400 turns at near 200 kHz 20" 
> above a ground plane. Putting an identical coil 1" above this coil 
> results in a drop in freq to about 130 kHz. The merit as I see it is 
> simply less wire, but there are breakdown obstacles to overcome not 
> only between stacks but also at the outer and inner edges.
>
> I don't know, just contemplating the possibility. Maybe someone's 
> software out there could look this. But again, the RF losses are 
> independent of coil winding approaches, so no benefit in that 
> respect. And if nothing else, I guess it could be converted to an 
> induction coil with a little work.
>
> It's hard to beat simplicity (single layer helical).
>
> Take care,
> Bart