Re: Spark-gap sparks vs. solid-state sparks

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Kennan C Herrick by way of Terry Fritz <twftesla-at-uswest-dot-net>" <kcha1-at-juno-dot-com>

John (& all)-

No, no instrumentation--just the eyeball.  But I remain dubious of such
an ion cloud for this reason (& remember, it's not an expert who writes
this):  Once ion #1 forms, due to an addition of an electron from the
toroid, then the next electron in line, so to speak, is going to see an
easier path to "freedom" and it's going to take it.  That, in my view, is
when the spark-avalanche begins.

I've observed, by looking at the e-field on the scope during my 7 ms
interrupted-sparking events, that the field increases very little after
each ~400 us cessation of energy.  So something is preventing that field
(electric potential) from increasing, during those off-times.  But, as
I've said, I'd think that that would be the heat of the air rather than
residual ionization, because of that relatively long time duration.

Although...I'm again reminded of my other, failed-product, invention
which I called "Neon Bubbles".  There, I created and controlled a
standing-wave of ionization in a neon tube.  Such a tube would operate at
an excitation frequency, dependent on the tube diameter, of as low as 1
KHz or even less.  The maintenance of that standing wave--strikingly
visible, which is what might have made it a successful product in the
sign industry, alas--at such a low frequency must mean that ionization
remains in the tube between the half-cycles of that excitation.  If it's
so in a neon tube then it's so in free air, so maybe you're right.

And I think there's another point to be made as to the "delay":  Hot air
or residual ionization are both going to make it easier for sparks to
form, so neither phenomenon is going to offer any delay mechanism.  But
for each and every spark one can hear the air first expanding, then
necessarily contracting again: that, of course, being the thunder--one
crack! for every spark.

--->Any light to be shed on this matter by experts??<---

To pursue the ion/heat question, what I intend to do is to vary the
inter-spark duration, as I wrote, & see what happens.  And also, perhaps
to arrange a test to blow air rapidly across a break-out ball (using that
to confine the spark locus) to see whether in doing so I can cause the
e-field to rise noticeably, between the mini-sparks, as viewed on the
scope.  That would support my hot-air theory.  (Don't know if I've put
that quite right; oh well...)

And speaking of sparks...I've just engaged my son to take some fine
photos of my coil running.  Multiple-exposure images, of course, and
quite spectacular.  He used a 4x5 view camera to make color slides & then
scanned the images into his computer & ran me a couple of 8" x 10"
prints.

I hope to make up a small Web site soon, after learning how, & perhaps
put it on hot-streamer if Terry's hospitality there is still on offer. 
So far, some 3.5 MB for a 300 dpi image and a whopping 15-odd for 600 so
perhaps I wouldn't use the latter.

Ken Herrick


On Sat, 21 Apr 2001 11:22:15 -0600 "Tesla list" <tesla-at-pupman-dot-com>
writes:
> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" 
> <FutureT-at-aol-dot-com>
> 
> In a message dated 4/20/01 7:46:16 PM Eastern Daylight Time, 
> tesla-at-pupman-dot-com 
> writes:
> 
> > John (& all)-
> >  
> >  If there's an ion cloud there, I sure can't see it.  But it seems 
> certain
> >  that there's none there after the coil sits for a while & then I 
> hit it
> >  with 1 spark.  And just 1 spark acts, for me, exactly like 
> repetitive
> >  ones except, as I've written, when they are very close together 
> in time. 
> 
> Ken, all,
> 
> I meant that the ion cloud may be formed as the coil rings up,
> but before the spark breaks out.  So after the coil is sitting for 
> awhile,
> I agree there would be no ions.  But as soon as it begins to ring 
> up,
> the ions will be formed prior to breakout.  The presence of these 
> ions
> may affect how the spark behaves and grows when it breaks out.
> A slow ringup may form an ion cloud of one type, a fast ringup may
> form an ion cloud of another type.  By type, I mean the size, or
> intensity, or whatever.    I believe you mentioned in another 
> posting
> that the frequency shifted more before the spark broke out than it
> did after.  This suggests the presence of a significant ion cloud
> before breakout, unless there is some other explanation?
> 
> You say you did not see the ion cloud.  Well it would not be 
> visible
> by eye.  Did you mean by eye, or with instrumentation?
> 
> I don't know enough about the physics involved to have an opinion
> about the inertia theory.
> 
> Cheers,
> John
> 
> 
> 
> 
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