Re: Wireless Power Transmission (fwd)

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---------- Forwarded message ----------
Date: Thu, 24 May 2007 09:52:54 -0600
From: Gary Peterson <g.peterson@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Wireless Power Transmission

----- Original Message ----- 
Subject: Re: Wireless Power Transmission

On March 24, 2007 Tesla Coil Builders List wrote:
> A Tesla coil would certainly have to be about the size of Tesla's 
> Wardenclyffe tower and according to Gary P. would have to have at least 75 
> kW output to even maintain such a standing wave . . .

Tesla designed a global wireless energy transmission system that he stated 
was capable of operating at 99% efficiency.  It was based upon a 
7.5-megawatt Tesla coil RF transmitter and was intended for the transmission 
of electrical energy on an industrial scale.

     "Much has already been done towards making my system commercially 
available, in the transmission of energy in small amounts for specific 
purposes, as well as on an industrial scale." ["The Transmission of 
Electrical Energy Without Wires," Nikola Tesla, Electrical World and 
Engineer, March 5, 1904.]

     "Theoretically, it does not take much effort to maintain the earth in 
electrical vibration.  I have, in fact, worked out a plant of 10,000 
horse-power [about 7.5 million watts] which would operate with no bigger 
loss than 1 percent of the whole power applied; that is, with the exception 
of the frictional energy that is consumed in the rotation of the engines and 
the heating of the conductors, I would not lose more than 1 percent. In 
other words, if I have a 10,000 horsepower plant, it would take only 100 
horsepower [or about 75,000 watts] to keep the earth vibrating so long as 
there is no energy taken out at any other place." [NIKOLA TESLA ON HIS WORK 
WITH ALTERNATING CURRENTS AND THEIR APPLICATION TO WIRELESS TELEGRAPHY, 
TELEPHONY AND TRANSMISSION OF POWER, Leland I. Anderson, Editor, Twenty 
First Century Books, 1992, p. 140.]

For telecommunications alone a much less powerful transmitter is sufficient.

     "The results attained by me have made my scheme of intelligence 
transmission, for which the name of "World Telegraphy" has been suggested, 
easily realizable.  It constitutes, I believe, in its principle of 
operation, means employed and capacities of application, a radical and 
fruitful departure from what has been done heretofore.  I have no doubt that 
it will prove very efficient in enlightening the masses, particularly in 
still uncivilized countries and less accessible regions, and that it will 
add materially to general safety, comfort and convenience, and maintenance 
of peaceful relations.  It involves the employment of a number of plants, 
all of which are capable of transmitting individualized signals to the 
uttermost confines of the earth.  Each of them will be preferably located 
near some important center of civilization and the news it receives through 
any channel will be flashed to all points of the globe.  A cheap and simple 
device, which might be carried in one's pocket, may then be set up somewhere 
on sea or land, and it will record the world's news or such special messages 
as may be intended for it.  Thus the entire earth will be converted into a 
huge brain, as it were, capable of response in every one of its parts. 
Since a single plant of but one hundred horse-power [or about 75,000 watts] 
can operate hundreds of millions of instruments, the system will have a 
virtually infinite working capacity, and it must needs immensely facilitate 
and cheapen the transmission of intelligence." ["The Transmission of 
Electrical Energy Without Wires," Nikola Tesla, Electrical World and 
Engineer, March 5, 1904.]

Assuming that Tesla was correct in his assertion that it requires, let us 
say, 75,000 watts to resonate the earth--and no evidence has been presented 
to the contrary--this means that a 75,750-watt system would be capable of 
operating at 1% efficiency.  The remaining 99% of the transmitted power 
would be consumed by various losses such as the production of eddy currents 
in the earth with their subsequent conversion to heat, acoustic energy, etc. 
and the minor production of electromagnetic radiation.  In the operation of 
this type of system, 75,000 watts of power will be needed to compensate for 
the 75,000 watts that for one reason or another is either absorbed by the 
environment or lost in the form of electromagnetic radiation.  Once again, I 
am talking about a system that is based upon a 75,750-watt transmitter.  In 
this case only 750 watts or about 1% of the energy available from the 
transmitter is available for consumption anywhere on the earth's surface. 
In other words, at an idle the transmitter will consume fully 75,000 watts 
simply to maintain earth resonance.  Add a single receiver with a 750-watt 
load attached to it or 100 million receivers each consuming .075 milliwatts 
of energy and the system will be maxed out.

> . . . but given a topload the size of Wardenclyffe, couldn't the coil be 
> designed such that one of the several Schumann resonance frequencies could 
> be an odd multiple of the resonant frequency's  'effective quarter wave 
> frequency wavelength'? . . . There are other frequencies a bit higher than 
> 7.8Hz as well.

As for frequencies, at Wardenclyffe Tesla operated from 1,000 Hz to 100 kHz. 
He found the frequency range up to 30 - 35 kHz, "to be most economical." 
Based upon an analysis of the "Colorado Springs Notes" and other sources, 
including Corum & Corum, it appears a basic World System oscillator would 
develop a wave complex with an extremely low frequency (ELF) component in 
the 12 - 1000 Hz range obtained with an alternator, plus a very low 
frequency (VLF) component around 25 kHz obtained by using a DC-powered Tesla 
coil resonant transformer with a high-speed break.  I believe it is unlikely 
the fundamental earth-resonance frequency will be found to coincide with the 
fundamental Schumann resonance frequency, which, by the way, drifts around 
in the area between 7.5 - 7.9 Hz.  Tesla spoke in no uncertain terms of a 
fundamental terrestrial resonant frequency of not more than 12 Hz that 
corresponds to a theoretical terrestrial resonance frequency of 11.787 Hz. 
The only way to know for sure that this terrestrial resonance actually 
exists is to try and repeat Tesla's previous measurement.

Here are some additional comments by Tesla on the subject of wireless 
transmission by means of his system.

Counsel

    What would an engineer have to do to the wireless systems of today in 
order to produce very little radiation of electromagnetic waves and produce 
a large amount of these earth currents?  What changes would he have to make 
in the system?

Tesla

    He would have to construct and operate the apparatus described in my 
patents and in my lectures.

Counsel

    He would have to get very much more inductance in the system than he has 
today, relatively?

Tesla

    It is just like this: In an enterprise of this kind, you have to start 
with certain fundamental propositions.  If you are to build a commercial 
plant, the question comes up how much money is it to cost.  Now, you go to 
specify before your capitalists the various parts of the plant, and you will 
find that your machinery and the aerial structure will cost so much.  If 
your capitalists are willing to go deep into their pockets, you can put up a 
tremendous antenna because, as you know, as I pointed out in 1893, that the 
effects will be proportionate to the capital invested in that part; but you 
will find great limits there.

    I designed a plant [Wardenclyffe, referring to Fig. 83] years ago with a 
large capacity and put it before certain architects.  They figured that the 
antenna would cost $450,000 and I had to modify my plans.  As you see, you 
are limited by cost as to the size of the antenna; that is, you are limited 
as to the capacity and, furthermore, you have selected the frequency.  In 
order to lower the frequency so that there would be no wasteful radiation of 
energy, you have to employ a large inductance.  You have to employ a 
capacity as large as permissible, and you must use a large inductance in 
order that you may reach the low frequency which is economical.

Counsel

    What low frequency is it that is economical?

Tesla

    In a patent which appeared in April 1905, the application of which was 
filed on May 15, 1900, I have enunciated the law of propagation, which I 
have explained, and have stated that the frequencies should not be more than 
30,000 or 35,000 cycles at most, in order to operate economically.

Counsel

    And would it also be necessary to provide for the high potentials of the 
order of which you have named in order to insure maximum direct currents and 
minimum electromagnetic wave radiation?

Tesla

    No sir.  The currents are proportionate to the potentials which are 
developed under otherwise equal conditions.  If you have an antenna of a 
certain capacity charged to 100,000 volts, you will get a certain current; 
charged to 200,000 volts, twice the current.  When I spoke of these enormous 
potentials [on the order of 12 million volts], I was describing an 
industrial plant on a large scale because that was the most important 
application of these principles, but I have also pointed out in my patents 
that the same principles can be applied to telegraphy and other purposes. 
That is simply a question of how much power you want to transmit.

Counsel

    In Colorado, which did you use?

Tesla

    I used the so-called Tesla transformer.  I did not have the high 
frequency machine with which I could develop as much energy for the 
experiments, but with my transformer I could get any amount of energy I 
needed.  That is why I used the transformer. . . .


Counsel

    I understand the situation.  Was the power ever turned into this antenna 
at Wardenclyffe?  Did you use it in that sense?

Tesla

    Oh yes. I used the antenna. I used it right along up to 1907.  I made my 
measurements and experiments, and I transmitted for the purpose of tests, 
energy and all that, but it never went further than is shown in the picture 
[Fig. 85].  Several times I spent $1,000 to paint the thing up, and that 
paint in a little while was off again.

Counsel

    And these times, when you turned the power into the antenna for 
experiments, what frequencies did you use?

Tesla

    I could operate from very low frequencies, from 1,000 cycles on -- to 
100,000, 150,000, or 200,000. I had every facility to operate with the 
lowest frequencies up to the highest.

Counsel

    How did you get those frequencies?

Tesla

    The low frequencies I usually got from an alternator, and then with this 
other apparatus the higher frequencies.

Counsel

    At what frequencies did you actually operate?

Tesla

    I operated according to the nature of the experiment, as I say, from 
very low frequencies up to 100,000, but most generally I operated with the 
frequencies which I explained in my patent, say up to 30,000, which I have 
found to be most economical.

Counsel

    What was the nature of those experiments you were making there?

Tesla

    The experiments were telephonic, telegraphic demonstrations, 
measurements of energy, and all that.

Counsel

    Was there any receiver station built in connection with this 
Wardenclyffe apparatus?

Tesla

    No, except that I used transportable apparatus with which I made my 
measurements and received. [NIKOLA TESLA ON HIS WORK WITH ALTERNATING 
CURRENTS AND THEIR APPLICATION TO WIRELESS TELEGRAPHY, TELEPHONY AND 
TRANSMISSION OF POWER, Leland I. Anderson, Editor, Twenty First Century 
Books, 1992, pp. 143, 155]

So there you have it.

Regards,
Gary

Gary Peterson
Phone: 970-453-9293
Fax: 970-453-6692
www.teslaradio.com
www.teslabooks.com
www.teslascience.org


> Original poster: Mike <megavolts61@xxxxxxxxx>
>
> A Tesla coil would certainly have to be about the size of Tesla's 
> Wardenclyffe tower and according to Gary P, would have to have at least 75 
> kW output to do even maintain such a standing wave, but given a topload 
> the size of Wardenclyffe,  couldn't the coil be designed such that one of 
> the several Schumann resonance frequencies could be an odd multiple of the 
> resonant frequency's 'effective quarter wave frequency wavelength'? 
> Musically, this would be like hitting the harmonic on the 12th fret (one 
> octave above the fundamental frequency) or the next octave harmonic on the 
> 5th fret(two octaves above the fundamental tone).  Doing that certainly 
> creates a standing wave on the guitar string even if not at the 
> fundamental frequency.  There are other frequencies a bit higher than 7.8 
> Hz as well.
> Mike
>
>
> Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>
>
> I've never heard of any Tesla coil tuned to anything remotely near 7.83 
> Hertz - have you?
>
> Gary Lau
> MA, USA