Re: van de graaff tube (fwd)

[<sroys@xxxxxxxxxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 29 Nov 2004 18:29:28 -0200
From: Antonio Carlos M. de Queiroz <acmdq@xxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Cc: hvlist <hvlist@xxxxxxxxxxxxxxxxx>
Subject: Re: van de graaff tube (fwd)

High Voltage list wrote:

> From: colin heath <colin.heath4@xxxxxxxxxxxx>

>         i was given some tube from work which is 7/16" wall thickness so i thought i haver rollers waiting and this is perfect for mounting the rollers on. so my question is, this stuff is black pvc (i think) but worst case it could be conductive! will this affect things? im guessing it wont as nothing will be touching it but you never know. i know black pvc works fine as a tesla coil former but this is a different beast. i will be aiming for 2.5" wide belt and this stuff is 4" and i hope to hav
> any help much appreciated

Any significant conductivity will impede work, since these machines work
with small currents, a few uA, or tens of uA at most. The terminal
touches
the tube, and even if not touching, sparks a the voltages generated can 
jump several cm of air easily.
Verify if the tube can be electrized by friction. If it can, there is a
good chance that it will work. If not, forget it.

Antonio Carlos M. de Queiroz