Re: [TCML] Sucker Gap

["Phillip Slawinski" <pslawinski@xxxxxxxxx>]

Gary,

I had read this on your website before, I guess I just forgot.  [I enjoyed
your website very much by the way.]  It's odd that this never happened with
any of my other NSTs, or maybe I just did not notice it?  I think I'm just
going to go to a rotary gap, I was having some power handling problems with
the gap last time I ran the coil.  The last time I ran it was with a 15/120
and .025uF cap.  This time I'm going to be running a 12/240 with a .05uF
cap.  I worry that with that power level the PVC may burn or melt after a
minute of runtime.

On Thu, Jul 24, 2008 at 7:39 AM, Lau, Gary <Gary.Lau@xxxxxx> wrote:

> Hi Phillip,
>
> I found exactly the same thing occurring on my sucker gap.  I detailed the
> observation on my sucker gap web page
> http://www.laushaus.com/tesla/onegap.htm:
>
> (Start of quoted text)  I performed an experiment to better observe the arc
> geometry in this gap. By disconnecting the tank components and having the
> NST output arc directly into the gap, the arc runs at a much lower current,
> and is less brilliant and safer to look at. The result was not at all what I
> expected. Rather than forming a ring between the two reducer faces
> originating at the copper half-torus, 95% of the arc was in a slender line
> precisely centered in the holes through the brass reducers. I couldn't see
> where this line of arc terminated so I replaced one of the PVC pipes with a
> clear acrylic pipe. The arc did not extend beyond the downwind (closest to
> the vacuum motor) end of the reducer (not surprising), but did stay centered
> throughout the fitting. The connection between the arc and the fitting was
> also surprising. The best way to describe it is like a bottle brush. The
> main arc travels down the center of the brass reducer, like the handle of
> the brush. Then, the arc connects to the reducer through a very large number
> of much smaller arcs, perpendicular (or nearly so) to the main arc, like the
> bristles of the brush, over the length of the reducer. (End of quoted text)
>
> My theory is this.  I'm guessing (WAG) that the air density is lowest along
> the central axis where the low power arcs were observed.  Low density air is
> more easily ionized than higher pressure ambient air, so that's where the
> ionization occurs.
>
> As to why the short, high current arc occurs between the electrode faces,
> while the low current arc occurs in a slender line through the axis of the
> gap - this is a mystery to me.  Perhaps we simply can't see what's happening
> with the tank circuit configuration, since it's too bright to observe
> safely.  Or, maybe that all arcs START where the gap is physically shortest
> (between the electrode faces), but progress thereafter to the low pressure
> areas.  But in the high powered config with the tank circuit, the energy is
> gone right after the initial bang?
>
> But the short answer is that I think your gap is operating normally.
>
> Regards, Gary Lau
> MA, USA
>
>
>
>
> > -----Original Message-----
> > From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> > Behalf Of Phillip Slawinski
> > Sent: Wednesday, July 23, 2008 9:37 PM
> > To: Tesla Coil Mailing List
> > Subject: [TCML] Sucker Gap
> >
> > I just hooked up my new NST to my sucker gap to test gap width.  A very
> odd
> > thing happened.  It had what appeared to be a power arc inside despite
> the
> > vacuum motor running.  There was a 2mm thick plasma rod in the very
> middle
> > of the electrodes that extended down the tube.  With every other
> transformer
> > I have a ring of blue sparks forms around the outside.  Only a half
> circle
> > of blue sparks formed this time, in addition to the plasma in the middle
> of
> > the gap.  Could this be a sign that my sucker gap ... sucks?  Perhaps
> it's
> > time to upgrade to a rotary?  If it can't even quench the NST without a
> cap
> > there's no way it can quench it with one, right?
> >
> > Has anyone else seen this before?
>
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