130 kW Coil Waveforms

To: "'Tesla List'" <tesla-at-pupman-dot-com>
Subject: 130 kW Coil Waveforms
From: Tesla List <tesla-at-stic-dot-net>
Date: Fri, 27 Mar 1998 07:22:24 -0600
Approved: tesla-at-stic-dot-net

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From:  Greg Leyh [SMTP:lod-at-pacbell-dot-net]
Sent:  Thursday, March 26, 1998 6:20 PM
To:  Tesla List
Subject:  130 kW Coil Waveforms

Hi All,

I have posted six JPEGs of current waveforms, including 
msmts at the base of the secondary, as well as currents
to and from the sphere, *measured from within the electrode.*
These can be viewed on:
http://www.lod-dot-org/electrum/electrumstatus.html


A few comments on these waveforms:

  Secondary base current, at 160BPS -
This shows the Isec gnd return current.  The quenching
is not optimal, due in part to the slow gap rotor speed.

  Coil-to-sphere and sphere-to-arc currents, 100uS/div -
Shows the arc current suddenly starting as the sec builds 
to max value.
Arc current reaches only about 40% of the total coil current.
An important observation here:  The peak current values at
the top of the secondary (~50A) are roughly equal to those
measured at the base of the secondary, strongly implying 
that this secondary coil acts for the most part as a lumped 
L and C resonant xfmr, and *NOT* as a 1/4 wave resonator,
as Tesla and others have suggested.

  Coil-to-sphere and sphere-to-arc currents, 20uS/div -
A closer view of the sec beat envelope, and the onset
of the arc.  Note the rich spikey content at the peaks
of the arc current.

  Coil-to-sphere and sphere-to-arc currents, 10uS/div -
The non-linear nature of the arc current is now noticable.

  Coil-to-sphere and sphere-to-arc currents, 5uS/div -
Blurry, but readable.

  Coil-to-sphere and sphere-to-arc currents, 2uS/div -
Here is evidence of the pulsating, dart-leader like nature
of the arc as it advances, similiar in fashion to the dart
leaders observed in natural lightning.  
These pulsations have time structures on the order of 400nS, 
with peak dart leader currents often in excess of 20A, as opposed 
to 20uS periods for big cloud strikes, with peak dart leader 
currents of several hundred amperes.  
This may explain in part as to why a larger toroid may 
help arc length, especially if it provides a lo-Z reservoir 
for these fast current pulses.

Comments welcomed.

-GL