Re: Toroid Behavior

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

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 


One must keep in mind these are direct current or small pulse rate breakout
levels.  Or breakout values in air with no ground electrode nearby.  At high
pulse rates or RF pulse rates the breakout value changes.

We have a medium size coil with 24 x 6 inch toroid measured output at 184 kV
(measured with Terry's planar antenna and also DC single pulse shot
operation).  This is far below the 501 kV breakout level mentioned below. It
breaks out to a 6 inch ground electrode in single shot mode (1 pulse every 5
sec) and is in close agreement with measured peak DC values.

Coil's max peak potential is 184 kV and at 380 pps it produces 5 1/2 ft long
sparks.

Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913
 >
 > With Antonio's new field mapping tool, I have been able to perform some
 > paper experiments to get a better feel for what parameters of the toroid
 > affect what.  I have done three experiments all centered around a 6x24
inch
 > toroid (since this is what I'm planning for my next coil).  Three results
 > are given for each experiment:  Vbreakout (Vbo), Ctop, and Reach.  All of
 > these were determined with the toroid hanging in free space with nothing
 > else attached (like a secondary).  Reach was an attempt to determine how
 > far the field "reaches" out to help with streamer formation.  I used
 > Antonio's probe capabilites to measure the field at a distance from the
 > toroid surface (horizontally) and found the distance where the field was
 > 1/10 (arbitrarily chosen for comparison purposes) of the value at the
 > toroid surface.  The potential of the surface was set to Vbo for this
 > purpose so the reach distance is the distance horizontally away from the
 > surface where the E field dropped to 300,000 V/m.  The surface field
 > strength would be 3,000,000 V/m
 >
 > Experiment #1: Vary major diameter with minor set to 6 inches
 >
 > size       Vbo      Ctop        Reach
 > ------------------------------------------------
 > 6x18   430KV   20.6pf   12.2inches
 > 6x20   455KV   22.5pf   12.9inches
 > 6x22   478KV   24.4pf   13.6inches
 > 6x24   501KV   26.3pf   14.2inches
 > 6x26   522KV   28.1pf   15.0inches
 > 6x28   542KV   30.0pf   15.5inches
 > 6x30   562KV   31.8pf   16.0inches
 >
 >
 > Experiment #2:  vary minor diameter with major set to 24 inches
 >
 > size       Vbo      Ctop        Reach
 > ------------------------------------------------
 > 3x24   358KV   24.1pf   10.0inches
 > 4x24   412KV   24.9pf   11.6inches
 > 5x24   460KV   25.6pf   13.0inches
 > 6x24   501KV   26.3pf   14.2inches
 > 7x24   540KV   26.9pf   15.3inches
 > 8x24   579KV   27.5pf   16.3inches
 > 9x24   606KV   28.0pf   17.2inches
 >
 >
 > Experiment #3:  vary both minor and major diameters maintaining constant
Vbo
 >
 > size       Vbo      Ctop        Reach
 > ------------------------------------------------
 > 5x29   506KV   30.2pf   14.2inches
 > 5x28   498KV   29.3pf   14.1inches
 > 6x24   501KV   26.3pf   14.2inches
 > 7x21   502KV   24.1pf   14.3inches
 > 8x19   505KV   22.7pf   14.4inches
 >
 >
 > Most of us knows that major diameter mostly affects capacitance and minor
 > diameter mostly affects breakout voltage, but the results of experiments
#1
 > and #2 show to what degree major diameter affects breakout and minor
 > diameter affects capacitance.
 >
 > The results of experiment #3 suggests that reach is mostly a function of
 > breakout voltage.
 >
 > Comments welcomed
 >
 > Gerry R
 > Ft Collins, CO
 >
 >
 >