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

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "S&JY" <youngsters@xxxxxxxxxxxxxxx>

Peter,

If you search the archives, you will find that years ago Richard Hull built
a magnifier coil that was only 12 inch long, had a gigantic toroid on it
(actually under it - he ran it inverted), and produced 10 foot
streamers/leaders.  So the ratio for his coil is 10:1.  But if you add in
the height of the secondary coil that drove the extra coil, the ratio may be
less than 4:1 and you might well beat his achievement.  So, for magnifiers,
does the height of the secondary "count" or not?
--Steve Y.

----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Tuesday, September 20, 2005 10:30 AM
Subject: Re: Stack of flat coils (was 8 kHz Tesla Coil)


> 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
>
>
>
>
>
>