RE: Spheres vs Toriods

Richard and coilers,

>The sphere is obviously the better terminal for voltage buildup, but it 
>offers zero electrostatic shielding or shanding of the top of the tesla 
>coils resonator.  It is not stackable or attachable to a lot of systems 
>without boring holes in it.  As you say, it is the most expensive form of 
>terminal to spin and weld to perfection.  All of these points add up to the 
>sphere actually being the worst terminal for a Tesla coil.  

I must add here, that while spheres are a 'bad' terminal capacitance to
use under most conditions, one interesting phenomena I noticed using a
nice shiny sphere was the 'single tenticle effect'. Something that doesnt
occur on torroids to the same extent. One long streamer (discharging into 
air) 'swinging' in a random fasion all over the place.....walk up cautiously
and outside strike distance of course, and sometimes you can coax the streamer
to swing round and 'look you in the eye' so to speak.....quite entertaining!
If you have never tried it before, its worth a go just for the effect! Keep
those torroids for the big sparks though!! Another use I found with spheres
is isotropic loading configurations to create a minimal capacitance 'needle'
discharger. Though fairly inefficient these are great for powering up spinners.
.......At the end of the day torroids win of course!!!!!
>The fact that 
>the sphere or some form of oblate is both theoretically and in actuality the 
>ideal terminal for voltage standoff, doesn't mean beans if the coil hasn't 
>the proper shielding and field shaping to survive the rise of voltage that 
>the terminal can actually store.
>The tesla coil is a form of pulse charged electrostatic generator or charge 
>pump when very large terminal capacities are used.  This capacitance seems 
>to be best developed in Toroidial termnals provided large cross sectional 
>diameters are used.  The superb field shaping action and stackability of the 
>toroid shape makes it the number one choice for Tesla coils.
>Richard Hull, TCBOR

Ive been wondering what a true torroid is latley. It seems that with the use
of metallic spreaders the torroid will become an approximated disc or a
super flattened out sphere in a sense. What will be the difference(if any)
of using a 'pure' torroid with a plastic spreader and say a srap connecting
the resonator to one point on the inner cavity of the torrus? It is obvious
that a small amount of capacitance will be lost without the 'pizza pans', but
will there be any change in the ES feild charachteristics. Approximated disc
or torroid...Hmmmmm.................?