Re: [TCML] Interesting pages on Q factors

["DC Cox" <resonance@xxxxxxxxxxxx>]

The Q factor is not as important as many earlier physics books suggest.
Their recommendations were based on coils with a very small topload, usually
a small sphere.
There is also a substantial difference between static Q and dynamic
operating Q factor.
The dynamic operating Q factor can be measured with an O-scope whereas
JAVATC calculates the static Q factor.  Operating Q factors are typically in
the range
of 10 to 50 for medium size coils.

Richard Hull wound several coils with relatively thin wire (28 AWG) and
still produced 12 ft long sparks in a magnifier configuration.

Going to a large 24 inch dia will tremendously improve your coils
performance, 8" to 24" will increase potential by a factor of 900% (  (24/8)
^ 2).

I would suggest 1,200 turns on your coil, then use a h/d ratio of 4.5:1
With a 24" dia coil, then 24 x 4.5  =  winding length of 108"

108" / 1,200 turns  =  .09" dia wire      12 AWG is .0951" in double build
insulation, so this would be a good choice for wire size.

Don't skip on your spark gap design as poor quenching could be very damaging
to your capacitor bank (mechanical analogy = putting your car in neutral
and flooring the accelerator pedal.  The energy has to have somewhere to go,
and if quenching is poor, it keeps being bounced back into the primary.  You
want it to be absorbed and ring out in the sec coil.

Sounds like a very powerful coil!

Dr. Resonance




On Mon, Aug 25, 2008 at 9:04 PM, Jim Mora <wavetuner@xxxxxxxxx> wrote:

> Hello Friends,
>
> Who else has done coil analysis of high Q coils?.  My 8" coil which was
> wound with 22 Awg 200 degree insulation and coated with oil based Poly. A 4
> to one ratio, the secondary's Q was somewhat disappointing where the degree
> 15 turns was very high and was coupled to a .03Uf cap. Of course throw
> enough power at it and it does very well.
>
> My next coil will be 22" to 24" very well dried and coated inside and out
> after the coating is removed.
>
> Perhaps DC Cox or Jeff P will chime in with their experience with these
> sized coils. The Q is largely a test of quality of a great verses a weak,
> so
> so coil. I want a very sharp peak, not a wimpy one that is hard to turn
> too.
>
> Thanks, Jim Mora
>
> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
> Of Chris Swinson
> Sent: Monday, August 25, 2008 3:13 AM
> To: Tesla Coil Mailing List
> Subject: [TCML] Interesting pages on Q factors
>
> Not sure if anyone has read this but looks very interesting.
>
>
> http://www.w8ji.com/loading_inductors.htm
>
> http://www.w8ji.com/inductor_spice_model.htm
>
>
> Chris
>
>
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