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Re: A Puzzle
From: Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent: Sunday, September 07, 1997 4:53 PM
To: tesla-at-pupman-dot-com
Subject: Re: A Puzzle
Hi Gary,
I am seriously leaning towards the view that Ctot in the
secondary system has a lot to do with it. That is the one thing that
_always_ increases with coil size. For example, you could go to a much
bigger resonator size but the keep the frequency high by winding
comparatively few turns. Such an approach will not do a lot for
primary losses however.
Malcolm
> From: gweaver[SMTP:gweaver-at-earthlink-dot-net]
> Sent: Saturday, September 06, 1997 9:46 AM
> To: Tesla List
> Subject: Re: A Puzzle
>
> I am not sure I can add much to what has already been said. I have noticed
> something similar with 2 coils that I have.
>
> Both my coils are wound on white pvc pipe. Both have 998 turns of #24 wire.
> The small coil measures 4.5" diameter and the larger coil measures 6.5"
> diameter.
>
> I built a TC designed for the small 4.5" coil. When I replace the 4.5" coil
> with the 6.5" coil and keep everything else the same the output sparks are
> about 2" longer. The thing that is most noticable is the larger coil
> produces much thicker and hotter spark.
>
> Small coil inductance is 21459 uh and the larger coil is 43124 uh and
> increase of 200.9%
>
> Wire length increased by 523" and increased the resistance from 27.1 to 39.2
> ohms.
>
> Ratio of the small coil is 4.8 and the ratio of the larger coil is 3.3.
>
> Q has increased by 15 unloaded.
>
> Small coil resonance frequency is 386.1 KHz compaired to 239.0 KHz for the
> larger coil.
>
> I can clearly see a difference between the output of the 2 coils but I can
> not tell you exactly what caused the difference.
>
> Gary Weaver
<snip>