From: boris petkovic
Date: Tue, 5 Nov 2002 09:18:01 -0800 (PST)
Subject: Re: [TSSP] Top Voltage
> > Hi Bert, > > > > > >>Streamer and leader propagation should occur only > as > >>the top terminal > >>has an increasing potential - i.e., during ringup > - > >>and not during > >>ringdown. > > > > --- > > Can you always put your money on this ? > > I wouldn't.It is a rare event I guess ,butI saw > > scoping pic of TC where arc attached to a grounded > rod > > during ringdown period .It is indication to me > that > > arc can propagate during ringdown in some > > situatuations as well. > > What about leader propation in a natural lightning > ? > > Source (pocket charges of cloud ) doesn't rise > > difference of potential with respect to ground as > > leader propagates.The electromagnetic thing > (except > > avearage leader current field)which is increasing > is a > > field at ground surface since leader by its' > evolution > > carries its' strong space charge field. > > --- > > I guess never say never... :^) > > The specific case I was thinking about was for Tesla > Coil air streamers > and leaders. --- Mostly I was thinking about them as well. --- If a TC leader and streamers have > already propagated most > of the way across a gap to ground, are close to > bridging the gap, and > the gap is now significantly overvolted, your > observation indicates that > it is then possible to make the final "jump" during > a lower voltage peak > (i.e., during ringdown). --- I agree that TC arcs tru air (far away of any grounded object) propagate for most of their lenghts during voltage ring-up.Part of ring-down period would then just serve for heating of already established path.Anyway I think that,even then, sparks propagate (slower though) for some percentage of final lenght. Terry has OLTC and is able to quench at will,right? If so,what do you think will the spark (single shot) be longer if : a)He quenches at first notch (as usual) b)He allows transfers of the energy primary-secondary-primary-secondary? I suppose ,to get clear experimental answer we should wait for rising of a primary voltage in 500 V+ range.(longer sparks) Cheers, Boris __________________________________________________ Do you Yahoo!? HotJobs - Search new jobs daily now http://hotjobs.yahoo.com/
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.