Re: Racing sparks vs. primary design

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

On 9 Jul 2005, at 13:59, Tesla list wrote:

> Original poster: Steve Conner <steve@xxxxxxxxxxxx>
>
> Hi all
>
> The discussion between John Freau and Jim Mora got me thinking.
>
> I have been wondering for a while whether the voltage profile on the
> secondary is determined by the shape of the primary. I think a little
> solenoid primary that hugs the bottom of the secondary will induce
> most voltage in the bottom of the secondary. Because of its small
> size, the field is very intense near to the primary coil and dies away
> quickly with distance, so it will roast the bottom of the secondary
> while hardly touching the top.
>
> Hence I expect it will give racing sparks sooner than a large diameter
> solenoid, cone, or pancake that "throws" the field further up and
> spreads it more evenly over the secondary. Even if both primaries had
> the same overall coupling coefficient.
>
> Does anyone have any thoughts on this?
>
> Steve Conner

It would be really interesting to see the primary field mapped onto
the secondary for differentcoil types and geometries. K only gives
the degree of coupling, not which portion is being coupled into most
although k=1 speaks for itself. Graphical modellers?

Malcolm