RE: space winding

["John H. Couture" <couturejh-at-worldnet.att-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

All -

The problem with discussing the Q factor of a Tesla coil is that more than
one Q factor is involved. If the person talking about TC Q factors does not
indicate which Q factor he/she is talking about there will be confusion.

David is correct about the Tesla Coil Design Manual. It does say that Tesla
coils with high Q factors are not desirable for spark gap Tesla coils. This
refers to operating Tesla coils. It does not apply to so-called tube or SS
Tesla coils. These devices use continuous waves instead of the dampened wave
of the true Tesla coil.

It appears that the only way to find the Q factor of an operating TC is by
the method I show in the Tesla Coil Notebook. This method utilizes the
equation
     Q = Pi/Log Dec
It is obvious from this equation that as the Log Dec increases the Q factor
decreases. The log Dec increases as the TC gets larger which gives lower Q
factors. This can be checked by tests with an oscilloscope.

It should be noted that the other Q factors related to the TC are greater
than the operating Q factor. The different Q factors of Tesla coils have
been discussed in earlier posts on the Tesla List.

John Couture

-------------------------

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Monday, August 07, 2000 4:02 PM
To: tesla-at-pupman-dot-com
Subject: Re: space winding


Original poster: Tesla729-at-cs-dot-com

Hi Malcolm, all,

I have had problems with turn/turn flashovers on several oc-
casions in the past. I'm guessing these problems stemmed
mostly from improper design/tuning on my part. IMHO, the
turn/turn flashover problem would not be alleviated by space
winding without correcting the design flaw(s).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.

Hey, this list is the greatest and thanks go to Chip and Terry
for their efforts which make this list possible so that big dum-
mies like myself can gain more and more knowledge each
day about these beloved lightning bolt generators that we
love to build called Tesla coils!

Good Safe Coilin,
David R.