[TCML] Tesla Coiling Without Sparks

[Gary Peterson]

Recently Ed Philips and I have been engaged in a Tesla coil related 
discussion, a small portion of which I would like to share with the list.

> Am I correct in my understanding that your objectives are to demonstrate 
> that there is a way to communicate energy from one point to another by 
> means other than mutual capacitance, mutual inductance, or electromagnetic 
> radiation?

That's not exactly what I have in mind.  My objective is simply to 
demonstrate that a low power Tesla coil transmitter-receiver pair 
communicates some of its energy from the point of transmission to the point 
of reception by a means other than electromagnetic radiation.

I notice that you use the term "mutual capacitance" and I'm not exactly sure 
what you mean by that.  What you mean by "mutual inductance" seems clear 
enough.  A single Tesla coil resonator has inductance or 'self-inductance' 
and two coils, like a Tesla coil primary and secondary, in fairly close 
proximity, couple together and thus have mutual inductance.  In contrast, a 
single capacitor has capacitance, but two capacitors placed in more or less 
close proximity are not similarly coupled by an electric field.  I think 
what you mean by mutual capacitance is simply "capacitance" so let's 
simplify things by dropping the word "mutual."

So, if the energy is not communicated entirely by means of electromagnetic 
radiation, that is to say, ordinary radio waves, how is it communicated?  We 
all know that one part of the circuit between the two points referred to 
above is the portion of the earth lying between the ground terminals of the 
Tesla coil transmitter and the Tesla coil receiver, and that the electrical 
energy propagates between these two points by means of conduction.

What about the other half of the circuit?  For a high-power Tesla coil 
system, the energy passes the same way as it does through the earth, by 
means of an electrical current flowing through a conductor, which in this 
case is ionized gas rather than soil and rock, etc.  But what about a 
low-power system, such as the low-budget Tesla coil builder might be 
interested in experimenting with?  Refined Tesla coil transmitters are known 
to be poor sources of radio waves and Maxwell's equations demand that for 
any type of launching structure, an elevated dipole, a grounded monopole, or 
a grounded top-loaded helical resonator plus a grounded receiving element, 
the electromagnetic field energy that appears out in the far-field zone must 
exist in the form of electromagnetic radiation.  Because of this a robust 
connection between the elevated terminals of a Tesla coil transmitter and a 
Tesla coil receiver would appear to be quite impossible.  Fortunately for 
us, and in spite of Maxwell's equations, such a robust connection is in fact 
possible, as has been repeatedly demonstrated over the last 110 years.

Here's a thought experiment.  Construct an electrical circuit in your mind 
consisting of a high-frequency single-phase electrical generator, each 
terminal of which is connected by a wire to a vertical metal plate.  Now 
position the two plates in close proximity to each other, forming an air 
capacitor, and set the generator in motion.  At this point an alternating 
electrical current can be said to flow from one generator terminal to its 
respective metal plate, then across the intervening space between the two 
plates by means of a displacement current, and then back to the other 
generator terminal.  This process repeats itself in the opposite direction 
during the next half of the electrical cycle and continues on and on as long 
as the generator is made to turn.  During the first half of each cycle all 
of the e-field pointers point in essentially the same direction toward the 
opposite plate.  During the second half of the cycle the pointers reverse 
and point in the opposite direction.

Now let's move one of the metal plates out to a position, say, three 
wavelengths or more away from the other plate, splice in a piece of wire, 
reconnect the distant plate to the generator, and set the generator back in 
motion.  The question is this: can the electrical field between the two 
plates be described in exactly the same way as it was when the two plates 
were closer together or do Maxwell's equations require that it take the form 
of the e-field component of an ordinary radio wave?

> I think you've intentionally eliminated direct conduction via the ionized 
> upper atmosphere with earth return as proposed in Tesla's patents and 
> writings because of the impossibility of demonstrating that on a small 
> scale and instead are looking for some other phenomena which can be 
> verified by reasonable performable experiments.  Is that correct?

I'll answer with a qualified yes and no.  First of all, we can by no means 
eliminate direct electrical conduction through the earth.  This portion of 
the circuit is essential in any instance of the Tesla wireless system that 
might be examined.  Second, Tesla has stated that in addition to conduction 
through ionized gas, electrical energy can also pass between two conductors 
through space by what he called "electrostatic induction."  There is some 
equivalence between electrostatic induction and Maxwell's "displacement 
current."  The phenomenon we are looking for is a 'displacement-like 
current' existing between two 'capacitor plates' that are spaced many 
wavelengths apart.  It is apparent from an examination of Tesla's writings 
that he was using this 'displacement-like' current from the very beginning 
of his research into wireless energy transmission using Tesla coils.

> . . . I'm trying to devise experiments which . . . would be definitive one 
> way or another. . . . In principle if one could define the transmitting 
> and equipment sufficiently accurately it would be possible to use 
> conventional theory to predict the exact amount of energy being delivered 
> and compare that to the amount actually measured by experiment.

Instead of depending solely on an abstract mathematical description of the 
Tesla coil transmitter, why not also measure its 'ordinary radio wave 
output' with a calibrated radio receiver?  There is every indication that 
when you do this you will find the radio-wave output is so low as to be 
undetectable, or nearly so, only a few wavelengths away from the Tesla coil 
transmitter, no matter how hard you try.  Of course, your Tesla coil 
transmitter must be highly refined.  The next step is to set up a refined 
Tesla coil receiver, tune in the Tesla coil transmitter, and measure the 
received signal strength.  If, under the same Tesla coil transmitter 
conditions, the strength of the signal indicated on the radio receiver is 
nil while the strength of the signal received via the Tesla coil receiver is 
somewhat more substantial, then the energy of latter received signal must 
have made its way from the Tesla coil transmitter to the Tesla coil receiver 
at least in part by some means other than ordinary radio waves.  In the 
words of Sir Arthur Conan Doyle,

"Once you eliminate the impossible, whatever remains, no matter how 
improbable, must be the truth."

Regards,
Gary

----- Original Message ----- 
> From: "Ed Phillips" <evp at pacbell.net>
>
> Gary:
>
>    . . .  I have been pondering this question for several days:  "If I 
> measure an electric or magnetic field strength at a point is there any way 
> to determine the mechanism which produced it?"  So far the only answer I 
> come up with is NO.  The measurement will give a value of voltage or 
> magnetic field but that's it.  If it were possible to do some sufficiently 
> accurate field distribution over a region of space measurements the answer 
> might be different.
>
>     Am I correct in my understanding that your objectives are to 
> demonstrate that there is a way to communicate energy from one point to 
> another by means other than mutual capacitance, mutual inductance, or 
> electromagnetic radiation?  I think you've intentionally eliminated direct 
> conduction via the ionized upper atmosphere with earth return as proposed 
> in Tesla's patents and writings because of the impossibility of 
> demonstrating that on a small scale and instead are looking for some other 
> phenomena which can be verified by reasonable performable experiments.  Is 
> that correct?  That's the approach I've been thinking about and I'm trying 
> to devise experiments which, if I performed them myself, would be 
> definitive one way or another.  So far no luck.  In principle if one could 
> define the transmitting and equipment sufficiently accurately it would be 
> possible to use conventional theory to predict the exact amount of energy 
> being delivered and compare that to the amount actually measured by 
> experiment.  Unfortunately I don't know of any way of doing this because 
> of the difficulties in defining the two ends of the circuit with enough 
> accuracy along with the additional one that affordable measurements of 
> electric and magnetic RF fields tend to have experimental errors of the 
> order of a few percent at best and that those errors would make it 
> impossible to detect anomalous amounts of energy transfer. . . .
>
> Ed