Insulation [small ball]

From: 	gweaver[SMTP:gweaver-at-earthlink-dot-net]
Sent: 	Sunday, August 03, 1997 12:57 AM
To: 	Tesla List
Subject: 	Insulation

What your trying to do goes against the nature of the Tesla Coil.  High
voltage sparks tend to travel away from the secondary coil and by putting a
small metal ball in the center of the coil you are trying to make the sparks
travel to the inside center then travel out again.

I tried the same thing once many years ago.  I have some ideas you can try.
If you have a 3" coil mount the metal ball on the bottom of an empty Tuna
Fish can which is 3" diameter.  If you have a 4" coil mount the metal ball
on the bottom of an empty Tomato can which is 4" diameter. Set the can on
top of your coil.  Now you will get sparks from the ball and also sparks
from the edge of the metal can.  If you mount the metal ball on the side of
the can and not the middle of the can you will get sparks from the ball.

Also try using a metal funnel.  Set the funnel on top of the coil with the
small end pointing up.  Set the ball on the end of the funnel.  This works
better than the metal can.  It is hard to find a metal funnel the exact side
of the coil these days because most funnels are made of plastic.  You might
be able to cover the funnel with aluminum foil or cut a funnel shape from
styrofoam and cover it with aluminum foil.

Its best to have something on top of your coil that is not smaller than the
diameter of the coil.

Gary Weaver

>I want to know how a person can stop your secondary's coil last winding from
>discharging. I have a small 1 inch diameter iron ball on top as a discharge
>sphere. But at the last turn on my secondary there comes a 4 inch spark out
>and that energy is lost and aren't going to my small sphere.
>Anyone have Ideas on how to overcome this problem. I don't want to use a
>large torroid to make an shielding effect.