From: FutureT@aol.com
Date: Sat, 11 May 2002 08:56:14 EDT
Subject: Re: [TSSP] Topload breakout potentials
--part1_34.2768e5a2.2a0e6eee_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 5/11/02 7:31:31 AM Eastern Daylight Time, paul@abelian.demon.co.uk writes: > These figures suggest that John's coil would break out much earlier > than Bart's, and would perhaps produce more but shorter streamers. Paul, all, I have the coil tuned so that the sparks barely break out at a full variac setting. This gives just about 2 simultaneous streamers, maybe 3. If I tune (tap) the primary for a higher frequency, then breakout occurs much sooner, but there are more streamers, but they are all shorter. It may be that the coil is somewhat mistuned this way (?), but it gives longest sparks this way. This may be why you had to set the tap point at 12 turns or so in the model, but I'm using 14.5 turns in reality. I have no idea if the present tune setting is contributing to racing sparks. I don't know if my tune setting is perhaps partially compensating for a too small toroid? (If such a thing is even possible.) For all my coils, I find that tuning "inward" gives earlier breakout with more but shorter streamers, and tuning "outwards" gives fewer but longer streamers, and delays breakout. I seem to remember that racing sparks are more likely to occur when tuned somewhat "inward" rather than outwards. I don't know if this is because the peak energy is higher due to a better tuning, or if it's actually mistuned that way, or perhaps simply because the coupling is tighter when tuned inwards. > Assuming a smooth toroid and a 26kV/cm breakdown threshold, it looks > as if Bart's topload shouldn't be breaking out at all without some > assistance from a breakout point. Maybe Bart's firing voltage is higher than he estimated? (Or maybe mine is lower.... ?).... or tuning issues are clouding the issue? Is Bart's toroid smooth? BTW, my tune point is a compromise. If I use a breakout point, I have to tune the coil differently for longest sparks, more outwards I think. But then the spark never breaks out without the breakout point. I don't know if others have seen this effect in their coils. Cheers, John > > I wonder if these characteristics are bourne out in practice? > > -- > Paul Nicholson, > --part1_34.2768e5a2.2a0e6eee_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 5/11/02 7:31:31 AM Eastern Daylight Time, paul@abelian.demon.co.uk writes:
These figures suggest that John's coil would break out much earlier
than Bart's, and would perhaps produce more but shorter streamers.
Paul, all,
I have the coil tuned so that the sparks barely break out at a full
variac setting. This gives just about 2 simultaneous streamers,
maybe 3. If I tune (tap) the primary for a higher frequency, then
breakout occurs much sooner, but there are more streamers,
but they are all shorter. It may be that the coil is somewhat
mistuned this way (?), but it gives longest sparks this way.
This may be why you had to set the tap point at 12 turns or so
in the model, but I'm using 14.5 turns in reality.
I have no idea if the present tune setting is contributing to
racing sparks. I don't know if my tune setting is perhaps
partially compensating for a too small toroid? (If such a thing
is even possible.) For all my coils, I find that tuning "inward"
gives earlier breakout with more but shorter streamers, and
tuning "outwards" gives fewer but longer streamers, and
delays breakout. I seem to remember that racing sparks
are more likely to occur when tuned somewhat "inward" rather
than outwards. I don't know if this is because the peak energy
is higher due to a better tuning, or if it's actually mistuned that
way, or perhaps simply because the coupling is tighter when
tuned inwards.
Assuming a smooth toroid and a 26kV/cm breakdown threshold, it looks
as if Bart's topload shouldn't be breaking out at all without some
assistance from a breakout point.
Maybe Bart's firing voltage is higher than he estimated?
(Or maybe mine is lower.... ?).... or tuning issues are clouding
the issue? Is Bart's toroid smooth?
BTW, my tune point is a compromise. If I use a breakout
point, I have to tune the coil differently for longest sparks,
more outwards I think. But then the spark never breaks
out without the breakout point. I don't know if others have
seen this effect in their coils.
Cheers,
John
I wonder if these characteristics are bourne out in practice?
--
Paul Nicholson,
--part1_34.2768e5a2.2a0e6eee_boundary--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.