Re: Source for Aluminum Spheres (up to 12" threaded)

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

Original poster: Bart Anderson <classi6-at-classictesla-dot-com> 

If you think about the voltage gradient along the length of the coil, the 
shielding or topload proximity affects the current and voltage distribution 
and changes the gradient. Regardless of what process is involved (i.e., 
streamer or avalanche) in initiating breakout at the secondary (vs. the top 
terminal), the voltage gradient is very much a real part of "will it 
breakout on the secondary or not" scenario. The shielding of a toroidal 
shape is very self evident in all of our coils.

When I've run with spheres or with toroids high above the top winding, I am 
far more prone to breakout from the secondary and thus limited to the 
degree of coupling, power input, etc. The toroids affect on the secondary 
voltage gradient is the main advantage in my minds eye.

Just my 2 pennies,
Bart

Tesla list wrote:

>Original poster: Esondrmn-at-aol-dot-com
>In a message dated 10/25/03 7:11:07 PM Pacific Standard Time, 
>tesla-at-pupman-dot-com writes:
>
>
>> > In what way better?  Clearly they work just fine but wonder what their
>> > edge is over a sphere with the same breakdown voltage.
>> >
>> > Ed
>>
>>
>>One way I can think of is that a toroid gives you mostly independent control
>>over the breakout voltage and topload capacitance.  The major diameter
>>mostly controls the topload capacitance.  The minor diameter mostly controls
>>the breakout voltage.  With a sphere, you don't have this level of control.
>>
>>Gerry R
>>Ft Collins, CO
>
>
>
>Also, the toroid will provide "shading" for the top few windings of the 
>coil so we don't get sparks breaking out from there.  I have tried spheres 
>on my three inch secondary and still had to have a small toroid on top 
>then the sphere raised up from there.
>
>Ed Sonderman
>
>