Re: space winding

[FutureT-at-aol-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

In a message dated 8/7/00 4:55:46 PM Pacific Daylight Time, tesla-at-pupman-dot-com 
writes:

> Hi Malcolm, all,

>  I can't argue with
>  the fact of higher Qs for a smaller guage sec wire nor am I per-
>  sonnally academically qualified to discuss this subject with
>  any authority. I do recall reading in J Couture's Tesla Coil De-
>  sign Manual that lower Qs are desirable in large Tesla systems
>  for longer sparks. I'll admit this does seem to go against typi-
>  cal wisdom along these lines, but I would have to agree that
>  naturally, you would have to opt for larger guage wire as the
>  power level increases.

David,

In a close wound coil, the proximity effect occurs, which makes
the wires behave as smaller wires than they really are, current-
wise, and this reduces the Q somewhat.  I remember reading
that the spacing between wires should be from 50% to 100% of
the wire thickness if I remember correctly.  I've always wanted
to try this, but didn't yet.  In any case, it's yet another reason
to use thinner wire.  Yes, as the power level goes up, and a coil 
gets larger, the wire sizes have to be scaled up more or less in
proportion.

I can't see any benefit to deliberately reducing the Q of the
primary or secondary components.  For longest sparks, the
highest possible Q should be best (as long as other important
rules of efficient design are not violated).

Cheers,
John Freau