From: FutureT@aol.com
Date: Thu, 28 Jun 2001 12:20:38 EDT
Subject: Re: [TSSP] Toroid breakdown voltage indirect meas.
In a message dated 6/27/01 6:21:22 PM Eastern Daylight Time, paul@abelian.demon.co.uk writes: > That's marvelous to hear. Fits in perfectly with the understanding > I've gained from reading Bert's posts about the breakout threshold > and streamer formation. Once that 26kV/cm is reached at the surface, > the streamer(s) can immediately form to considerable length. > > That seems to imply that any given toroid has associated with it a > minimum streamer length. Depending on your coil and voltage, you'll > either get no streamers, or streamers of at least this length. Paul, Interestingly, in a typical TC, by tuning outward on the primary (more turns), the streamer breakout is delayed. For example on my coil, when breakout occurs, the sparks jump outward to 42" or so. So the sparks are either long, or not there at all as mentioned. But if the primary is tapped for fewer turns, the toroid will breakout more easily, and can give much shorter sparks than 42", perhaps just 15" long or so.... They break out easier, but never grow as long. I figure this occurs because with the outward primary tune point, the coil is out of tune before the sparks breakout (delaying breakout) , but then moves into tune due to streamer and ion cloud capacitance, and pulls the coil into tune. Thus, longest sparks are obtained by slightly detuning the coil, but breakout is delayed. I remember this was discussed previously, but I forget what the conclusions were. I think some folks suggested the effects of tuning differences should be minimal. But I just wanted to say that this tuning aspect needs to be considered when considering minimum spark lengths for a given toroid. I have no idea what the topload voltages are under these different conditions though. Cheers, John Freau > > I expect Bert would say that this minimum streamer length is a function > of the stored topload charge and minimum radius of curvature. > > What happens when the voltage is raised above the breakout threshold, > do you get longer streamers, or just more of them, or both? > > Cheers, > -- > Paul Nicholson,
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.