Re: JavaTC and Coil Design

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: FutureT-at-aol-dot-com 

In a message dated 2/3/04 7:46:31 AM Eastern Standard Time, 
tesla-at-pupman-dot-com writes:

>I have been running some numbers on JavaTC for a new coil design, and have
>run into a slight problem. I am having trouble satisfying a secondary
>winding ratio of 4.5:1 or 5:1 with Malcom's recommendation of a wire 6 skin
>depths thick, and with John Freau's recommendation of 1200-1500 turns. Does
>anyone have thoughts on which of these are most critical to satisfy?
>
>Thanks,
>Gregory


Gregory,

I like a coil to be rather compact for its spark length.  The only
way to get high inductance on a small narrow secondary is to use
a lot of turns of a thinner wire.

To both keep the inductance high and obtain the 6 skin depths
will require the use of a wider dia secondary and thicker wire
with perhaps fewer turns.  This design should actually give
lower wire losses and still give good gap losses.  The large
secondary may require that a smaller toroid be used for a
given input power because of the large self-C of the large
secondary.  In the few comparisons I did, I didn't have
good results with this approach for whatever reason, but
I would like to explore the issue further.

John