Spark/Arc/Streamer - Model (by Terry Fritz)

To: wysock@ttr.com, Tesla List <tesla@pupman.com>

Subject: Private mail Re: IMPORTANT: RESEARCH ON WHAT?

From: Terry Fritz <terryf@verinet.com>

Date: Mon, 30 Nov 1998 18:24:11 -0700

Cc: "Wysock, William C." <Wysock@courier8.aero.org>, ken.corum@east.sun.com, jcorum@earthlink.net, rhull@richmond.infi.net

At 10:55 PM 11/29/98 +0000, wysock@ttr.com wrote:

<snipped>

>The point being this:  If you take a 3-coil

>system (master oscillator consisting of a primary and secondary,)

>and then use that system to dirve the input of a tertiary ("extra")

>coil, and if you look at what is happening to those component's

>electrical behavior on a Smith Chart, you will see that indeed, these

>elements do not act as "lumped-sum" inductances; rather they behave

>(in series) as a slow wave helical resonator (top load capacitance

>notwithstanding.)  In other words, on a Smith Chart, one can graph

>the ground connection point (input to the secondary [master

>oscillator] as "zero" on the chart.)  If you look at the output of

>this coil, (transmission line to the extra coil,) you will see that

>the phase has been rotated about such that the output at this point

>might represent about 20-25 degrees of phase shift.  Not 90 degrees.

Terry answers:

I would submit two cautions to this analysis:

First, the Smith chart is meant to study steady state situations only.  In

the case of Tesla circuits, the circuits operate under transient response

conditions.  Many of the fantastic output voltages of older theories make

this error in that they assumed high Q coils could resonate up to very high

voltages without considering that there was not enough energy available in

the primary system to ever support those high potentials.  A coil my have a

high Q but unless it can be feed with driving power for a substantial

length of time it will never be able to attain significant resonant rise

before the drive circuit runs out of energy.  Typically, the primary energy

falls far short of supporting this effect.

The second problem is that the output arcs present a very substantial load

to the system.  In order for a system to have resonant rise it must have

some rather nice Q value.  However, if you load a system with 220000 ohms

(our present estimate for arc loading) the system Q will drop like a rock.

The output is not simply a secondary (or extra coil in the three coil case)

and a capacitor.  The very substantial load of the arc must also be added

to the system.  I use 220k ohms plus a series 1pF for every foot of arc

<---- 220k + 13pF for 4m arclength !

length capacitor as a "model" of the arc load.  Testing with this model of

the streamer load has shown to be quite accurate (amazingly accurate

<---- streamer = arc ?

actually).

With the combined effects of transient behavior and arc loading, I feel

that the effects of Q, resonant rise, and phase shift and other

transmission line effects are lost.  The elements act as simple lumped

elements.  It is well known that a secondary coil can be fed with a signal

generator to create standing waves.  However, if you place a 220K ohm

resistor from the output to ground, the resonant rise will be damped and

the coil will act like a simple inductor.  Further more, if you pulse it

for the brief time as a Tesla coil uses, the effects will be suppressed

even more.  In transmission lines, there is significant phase shift of the

current between the base and the top of the line.  If it were a 1/4 wave

device it would be 90 degrees.  However, my direct measurements of

operating coils show no phase shift as I have written (there must be some,

but I can't see below 5 degrees well).  Thus the "trash the 1/4 wave

theory" posts to the list many months ago.  There is phase shift from the

top terminal (toroid) input to the streamers as Greg Leyh and I have shown.

It is this phase shift that we use to calculate the impedance of output

streamers.  This does affect the top to bottom phase very slightly but this

is due to loading and not Q effects.  The fact that his giant Electrum and

my little coil show the same ~220k ohm real resistance (although very

different capacitance) in the streamers still stuns me.  However, many arc

physics experts on the list thinks this is perfectly obvious.  I don't

understand all the ions, arc channel, plasma region... stuff but I get what

it means to the output load and I'll trust them.