Re: Wimshurst (tesla coil current)

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

Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 

Tesla list wrote:
 >
 > Original poster: John <fireba8104-at-yahoo-dot-com>
 >
 > Greetings Dr R,
 > The Winhurst might be my next project if I can find another microwave oven
 > disk- cheap, big , hard to break- under normal conditions, and a bi-product
 > of my microwave raiding.

Don't expect great performance with thick glass disks, or with any
regular glass disk. Rub your glass disk with something as paper, silk,
hair, or a dry hand. If it becomes easily electrized, there is some
hope that it will work. If it doens't charge at all (as happens with
regular alcaline glass), forget it.

 > The only real problem with these is drilling the holes.

Any store that works with glass, mirrors, etc. can make the holes
for you. Precise centering is the real problem. The best method to
make these disks is to start with the central hole and then cut the
disk from the plate. Very easy with plastics, not so with glass.

 > I want to go with a
 > sectored Winhurst since I prefer the ascetics over that of the sector-less
 > Winhurst. If I'm going to spend money on it, it might as well look good, at
 > least to me. Since my mind is set, I'm starboard, will the "shrouded pickup
 > electrodes" work with a sectored Winhurst?

I imagine that this means to put the collectors inside rounded
enclosures. Doesn't make great difference, because the charges will leak
anyway through the surface of the disks to the center of the machine
or to the adjacent neutralizers. The construction of all the high-
voltage conductors with thick tubes interconnected by balls makes
some difference. The most critical points are at the turn that the
charge collectors make around the disks and at their ends, pointing
in the direction fo the center of the disks. Any sharpness there
leads to large leaks by corona. A construction with balls and
tubes is adequate. As in my big sectorless machine:
http://www.coe.ufrj.br/~acmq/bbwhites1.jpg
http://www.coe.ufrj.br/~acmq/bbwhites2.jpg
http://www.coe.ufrj.br/~acmq/bbspark.jpg

 > Also, I'm planning on using a
 > dryer motor( a bit much?) instead of a hand crank so your recommendation on
 > using copper tubing has been taken into account, as well as everything else
 > stated in your post, since I'm going to need all the capacitance I can get
 > at dryer motor speeds.

What you will need mostly with a motor is a set of brushes that don't
destroy the disks. Make them so they touch the disks for startup and
then are moved to a small distance from the disks for operation
at high speed. Large or small capacitaces between sectors (?) don't
make great difference.

Antonio Carlos M. de Queiroz