Re: Spark Gap VI Scope Capture

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

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

Excellent suggestion...Except that isn't Terry just firing this off the HV
DC supply?

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, May 20, 2003 5:37 PM
Subject: Re: Spark Gap VI Scope Capture


 > Original poster: "Peter Lawrence by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <Peter.Lawrence-at-Sun.COM>
 >
 > Terry,
 > Jim,
 >      great experiment, and real nice looking data.
 >
 > I was wondering why the volts plot was not centered around zero like the
 > amps plot is, and why it has a net drift. I was thinking this could be the
 > NST 60-Hz voltage superimposed on the 100-KHz primary resonance, and we
 > are seeing just a tiny fraction of a 60-Hz cycle. Perhaps if you caught
 > different firings of the gap you would see the volts offset the other
 > way half the time.
 >
 > -Pete Lawrence.
 >
 >
 >
 >  >
 >  >Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>"
 > <jimlux-at-earthlink-dot-net>
 >  >
 >  >I've done some quick analysis..
 >  >First, if you decimate the data by 10 (and appropriately low pass filter
 >  >before decimating (I used matlab.. which filters at 0.8*Fs/2) you can
start
 >  >to see some real structure.
 >  >
 >  >There's a "low frequency" exponential looking offset in the waveform
that
 >  >extends over the entire waveform.  If you look at the expanded view
inside
 >  >the discharge, you can see that the voltage is essentially constant
during
 >  >the spark (which is sort of what you expect.  Assuming that the constant
 >  >voltage is straddling the real number, it looks like a voltage drop of
 >  >about 60-75 volts is a good representation of the "steady state part of
the
 >  >discharge.
 >  >
 >  >figures can be found at:
 >  >
 >  >http://home.earthlink-dot-net/~jimlux/images/vi1.png  - expanded view of
 >  >decimated data
 >  >http://home.earthlink-dot-net/~jimlux/images/vi2.png  - all data, decimated
by 10
 >  >
 >  >
 >  >At 12:32 PM 5/20/2003 -0600, you wrote:
 >  >>Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>
 >  >>
 >  >>Hi Jim,
 >  >>
 >  >>Looks like this:
 >  >>
 >  >>http://hot-streamer-dot-com/temp/03-05-20-01.gif
 >  >>
 >  >>I tried over smaller times spans but it did not really seems to show
much.
 >  >>
 >  >>Cheers,
 >  >>
 >  >>         Terry
 >  >>
 >  >>At 07:03 AM 5/20/2003 -0700, you wrote:
 >  >>>One might want to plot V vs I for the gap... While time domain
behavior is
 >  >>>interesting, I'd be interested to see the VI characteristic for the
gap...
 >  >>>
 >  >>>
 >  >>> > I have no idea where this voltage offset comes from but it seems to
 >  >>> > certainly have an effect on quenching here!!
 >  >>> >
 >  >>> > Much to ponder in this little spark ;-)))
 >  >>> >
 >  >>> > Cheers,
 >  >>> >
 >  >>> > Terry
 >  >>> >
 >  >>> >
 >  >
 >  >
 >  >
 >  >
 >
 >