Re: Terry's Test - Two Manifestations of Charge

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Antonio Carlos M. de Queiroz" <acmdq@xxxxxxxxxx>

Tesla list wrote:

> Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
> Hi Dave and All,
> I got the DRSSTC fixed this afternoon and tried to reproduce Dave's 
> unequal spark test.
> http://www.tesla-coil-builder.com/images/chiron01twosparks.jpg

I tried to reproduce the same experiment using an electrostatic
machine. It worked. And the explanation is trivial.
I placed a fluorescent tube over a metal plate (30x30 cm), over
an insulating support, and placed the two pins at one end of the
tube close to the two terminals of the machine. When the machine
operates, a continuous stream of sparks flows between the two
terminals and the two pins. Both identical due to the symmetry.
If I connect one of the terminals to the metal plate in contact
with the tube, the tube starts to glow and the sparks at that
side are clearly more intense.
The reason is simple: The tube over the plate is acting as a
capacitor, charged by the weak sparks. It discharges periodically
with an intense spark between the other pin and the terminal
connected to the plate, that is the outer plate of the capacitor.
(I observed that I can obtain a more intense effect if I made the
connection between the metal plate and the machine terminal through
a Leyden jar. The jar gets charged through the leakage across
the surface of the glass tube, and the sparks are longer.)
Using a Tesla coil, the mechanism may be essentially the same,
specially if someone is holding the tube.
I will try to take a picture tomorrow.

Antonio Carlos M. de Queiroz