From: Paul
Date: Mon, 07 Oct 2002 11:57:51 +0100
Subject: Re: [TSSP] Top Voltage
Jon, Terry, Thanks for the pointers to the pdf viewer. It worked! Although having read through http://hot-streamer.com/TeslaCoils/OtherPapers/phd_plank.pdf I'm not sure I'm any the wiser. Sure is a lot of physics going on. Marco wrote: > - AC application (different freq., DC component, rise time, etc.) > - successive pulses > - electrode shape Electrode shape, I think we can allow for, to some extent, so long as there are no sharp edges. But as for the breakout threshold, we are all at sea at the moment. > the above factors influenced the breakdown threshold so much > (e.g. 50%) Wish we could be as good as 50% :) Boris wrote: > Even in single shot mode of 38 kHz there can not be > 100 kv/cm at your electrode system without some > discharge going on there! I agree, we're so far out there must be something going on much earlier than we have observed. We need some rod/sphere probe current readings at voltages below the apparent breakout, to look for slight increase in the terminal capacitance caused by streamers that have not yet become visible leaders. It might also be possible to put a DC blocking cap in the secondary base lead, and look for a DC potential forming across it as first sign of breakout. That would require some ingenuity but no special probes or scopes. We must try to look for signs of less-than-visible breakout occuring within 50% or so of predicted values. Could it be that a lower-k system, taking a more gradual rise of topvolts, would show less discrepancy between the idealised breakout potential and the start of observable leaders? -- Paul Nicholson, --
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.