Reprinted from: ExtraOrdinary Technology
(Volume 4, Issue 2; Apr/May/Jun 2006)
Two of Tesla's devices representing different stages in the development of such a generator are identified.
He was told by
the professor that such a motor would require perpetual motion and
was therefore impossible. In the 1880's he patented the alternating
current generator, motor, and transformer.
Fuelless electrical generation raises the same objection of perpetual motion as did the generator in use today when it was first proposed. Research Nikola Tesla carried out during his second creative period and the resulting devices that were the basis for his assertion of fuelless electrical generation will be examined.
Whether Tesla's fuelless generator was a
"perpetual motion scheme" of the sort his teacher warned him
against, or a creative application of recognized natural phenomena
will be discussed.
Later on in the same article he said that,
In 1933, he made the same assertion in an article for the New York American, November 1st, under the lead in "Device to Harness Cosmic Energy Claimed by Tesla."
Here he said:
Dating back "more than 25 years ago" from 1933 would mean that the device Tesla was speaking about must have been built before 1908.
More precise information is available through his correspondence in the Columbia University Library's collection.
Writing on June 10th, 1902 to his friend Robert U. Johnson, editor of Century Magazine, Tesla included a clipping from the previous day's New York Herald about a Clemente Figueras, a "woods and forest engineer" in Las Palmas, capital of the Canary Islands, who had invented a device for generating electricity without burning fuel.
What became of Figueras and his fuelless generator is
not known, but this announcement in the paper prompted Tesla, in his
letter to Johnson, to claim he had already developed such a device
and had revealed the underlying physical laws.
The concept behind the older technical language is a simple one.
US Patent 685,957
An insulated metal plate is put as high as possible into the air.
Another metal plate is put into the ground. A wire is run from the metal plate to one side of a capacitor and a second wire goes from the ground plate to the other side of the capacitor.
This seems like a very straightforward design and would seem to fulfill his claim for having developed a fuelless generator powered by cosmic rays, but in 1900 Tesla wrote what he considered his most important article in which he describes a self-activating machine that would draw power from the ambient medium, a fuelless generator, that is different from his Radiant Energy Device.
Problem of Increasing Human Energy - With Special References to The
Harnessing of The Sun's Energy", it was published by his
friend Robert Johnson in The Century Illustrated Monthly Magazine
for June 1900 soon after Tesla returned from
Colorado Springs where
he had carried out an intensive series of experiments from June 1899
until January of 1900.
Tesla stated he first started thinking about the idea when he read a statement by Lord Kelvin who said it was impossible to build a mechanism capable of abstracting heat from the surrounding medium and to operate by that heat.
As a thought experiment Tesla envisioned a very long bundle of metal rods, extending from the earth to outer space. The earth is warmer than outer space so heat would be conducted up the bars along with an electric current. Then, all that would be needed is a very long power cord to connect the two ends of the metal bars to a motor.
The motor would continue running until the earth was cooled to the temperature of outer space.
Tesla goes on in the article to describe how he worked on the development of such an energy device, and here it takes a bit of detective work to focus on which of his inventions he meant. He wrote that he first started thinking about deriving energy directly from the environment when he was in Paris during 1883, but that he was unable to do much with the idea for several years due to the commercial introduction of his alternating current generators and motors.
It was not "until 1889 when I again took
up the idea of the self-acting machine(3)."
The unique point about this water pump is that instead of using some form of paddle wheels inside a box to move the water, he discovered that more water could be moved faster by using a set of flat metal disks.
The turbine is, in itself, fascinating and may yet prove to be another important overlooked invention, but what is of concern regarding the electrical design is the general shape of the turbine - metal disks turning inside a supporting box.
This same shape turns up in another patent, this one for a "Dynamo-Electric Machine" - click below image. This patent was filed and granted in the same year that Tesla said he returned to work on the "self-activating" machine, in 1889.
The dynamo consists of metal disks that are rotated between magnets to produce an electric current.
US Patent 406,968
Compared to his alternating current generator, this "dynamo" represents something of a curious throwback to the days of Faraday's early experiments with a copper disk and a magnet.
Tesla makes some improvement over the Faraday setup by using magnets that completely cover the spinning metal disks and he also adds a flange to the outside of the disks so current can be taken off more easily - all of which makes for a better generator than Faraday's.
On the surface, though, it is hard to
see why Tesla patented such an anachronistic machine at this point
in his work.
Then, at the close of the article, he states that,
Two years before the writing of that
article was 1889. All the evidence points to the turbine-shaped Unipolar Dynamo as being Tesla's first design for a machine that can
continue to produce electricity after being disconnected from an
outside source of power.
This has been clearly explained by Walter M. Elsasser in a Scientific American article (May 1958) titled "The Earth as a Dynamo."
Faraday Generator with electromagnet.
Elsasser models the earth-dynamo, conveniently for this explanation, on the Faraday generator of a metal disk spinning over a bar magnet placed at the edge of the disk.
He notes, also, that the bar magnet could be replaced by an
electromagnet which could get its power from the spinning disk by
attaching one end of the electromagnet's wire to the outside of the
disk and the other end of the wire to the metal rod running through
the center of the disk.
This conventional arrangement would
not be an answer to "how currents could be built up and perpetuated
to maintain the earth's magnetic field." He does, though, propose
three options in the dynamo model that would explain the earth's
If we could
build a coil-and-disk apparatus of this kind of scale of many miles,
we would have no difficulty in making the currents
What he did was to use energy that is
usually wasted in a generator and turn it into a source of power.
In the Faraday unipolar generator "the current," as Tesla noted,
Tesla’s modifications to the basic Faraday Generator also known as a unipolar generator.
By having the magnet completely cover the disk, Tesla made use of the whole disk surface in current generation instead of only a small section directly adjacent to the bar magnet, as happened in the Faraday device.
This not only increases the amount of current generated, but, by making the current travel from the center to the outside edge, makes all of that current accessible to the external circuit.
Eliminating the Back EMF
More importantly, these modifications on the Faraday design eliminated one of the biggest problems in any physical system - the reaction to every action.
It is this reaction
that works to cancel out whatever effort goes into causing the
original action. In an electrical system if there are two turns of
wire wound next to each other and a current is sent through the
wire, the current passing through the first loop will set up a
magnetic field that will work against the current passing through
the second loop.
Because the current is flowing in a large circle at the rim of the disk, the magnetic field created by the current not only does not work against the field magnet above the circular plate, as in conventional generators, but it actually reinforces the magnet.
as the disk cuts the magnetic lines to produce a current, the
current coming off of the disk strengthens the magnet, allowing it
to produce even more current.
Self-Running Mode of Operation
Both a generator and a motor disk are mounted in the magnetic enclosure. As the disks gain speed, current is produced which, in turn, reinforces the magnets, which cause more current to be generated.
is, likely, first directed to the motor disk which increases the
speed of the system. At a certain point the speed of the two disks
is great enough that the magnetic field created by the current has
the strength to keep the dynamo/motor going by itself.
In terms of Elsasser's criteria for a self-sustaining generator, the Tesla unipolar dynamo comes closest to satisfying the condition of a better electrical conductor.
not that a new material is used, but a new geometry is applied so
that the current does not create its own opposing forces. This is
similar, but not equivalent, to having a better conductor.
Instead of the opposite reaction slowing
down the system that created it, the reaction adds energy to the
An Energy Extraction Device
The dynamo would provide the energy to run a single machine, but his vision was to light cities and in the 1900 Century magazine article he elaborated on the theory of such a machine.
In this case, energy would flow from the outside environment, the high energy source, through the small opening at the bottom of the cylinder, and into the cylinder where there is less energy.
Also suppose that as the energy passing into the cylinder is converted into another form of energy as, for example, heat is converted into mechanical energy in a steam engine.
If it were possible to artificially produce such a "sink" for the energy of the ambient medium then,
He continued, in the article, to elaborate on his energy pump but changed the image slightly.
On the surface of the earth we are at a high energy level and can imagine ourselves at the bottom of a lake with the water surrounding us equal to the energy in the surrounding medium. If a "sink" for the energy is to be created in the cylinder, it is necessary to replace the water that would flow into the tank with something much lighter than water.
This could be done by pumping the water out of the cylinder, but when the water flowed back in, we would only be able to perform the same amount of work with the inflowing water as we did when it was first pumped out.
Energy, though, can be converted into different forms as it passes from a higher to a lower state.
For example, if the
energy of the ambient medium is taken to be the water, oxygen and
hydrogen making up the water are the other forms of energy into
which it could change as it entered the cylinder.
thus produce, by expending initially a certain amount of work to
create a sink for...the water to flow in, a condition enabling us to
get any amount of energy without further effort. (10)
He found that this pumping could be done with a piston "not connected to anything else, but was perfectly free to vibrate at an enormous rate."(12) This he was able to do with his "mechanical oscillator," a steam-driven engine used for producing high frequency currents. The faster the pump would work, the more efficient it would be at extracting energy from the cosmos.
Research along this line culminated in the oscillator demonstrated at the Chicago World's Fair in 1893.
Exhibit at the 1893 Columbian Exposition Chicago, Illinois
and insured his prominence in the electrical energy field.
In addition to numerous demonstration motors, the booth was highlighted by the infamous “Egg of Columbus”
in which a spinning egg illustrated the rotating magnetic field.
It was not until much later, in the 1900 article, he revealed:
It was also in 1893 that Tesla applied for a patent on an electrical coil that is the most likely candidate for a non-mechanical successor of his energy extractor.
This is his "Coil for Electro-magnets," patent #512,340. It is another curious design because, unlike an ordinary coil made by turning wire on a tube form, this one uses two wires laid next to each other on a form but with the end of the first one connected to the beginning of the second one.
US Patent 512,340
In the patent Tesla explains that this double coil will store many times the energy of a conventional coil.(14)
Preliminary measurements of two helices of the same size and with the same number of turns, one with a single, the other with a bifilar winding, show differences in voltage gain(15).
In below figure, the upper curve is from the Tesla design, the lower was produced by the single wound coil.
Preliminary measurements of two helices of the same size and with the same number of turns,
one with a single, the other with a bifilar winding, show differences in voltage gain.
The upper curve is from the Tesla design, the lower was produced by the single wound coil.
The patent, however, gives no hint of what might have been its more unusual capability.
The patent, however, gives no hint of
what might have been its more unusual capability.
As Tesla said,
What ties the Linde work with Tesla's electromagnet coil is that both of them used a double path for the material they were working with. Linde had a compressor to pump the air to a high pressure, let the pressure fall as it traveled through a tube, and then used that cooled air to reduce the temperature of the incoming air
by having it travel back up the first tube through a second tube enclosing the first.(17)
The already cooled air added
to the cooling process of the machine and quickly condensed the
gases to a liquid.
The earth, on the other hand, is charged with negative electricity.
electrical force between these two bodies constituted, at least in
part, what he called cosmic energy. It varied from night to day and
from season to season but it is always present.
With the gases of the atmosphere acting as an insulator between these two opposite stores of electrical charges, the region between the ground and the edge of space traps a great deal of energy.
Despite the large size of the planet, it is
electrically like a capacitor which keeps positive and negative
charges apart by using a non-conducting material as an insulator.
If the formula for calculating the
energy stored in a capacitor (E = 1/2CV2) is applied to
the earth, it turns out that the ambient medium contains 1.6 x 1011
joules or 4.5 megawatt-hours of electrical energy.
Explaining how this process might
have worked requires, again, speculation.
If the charge is used at a low
rate, the energy stored in the capacitive system will be turned into
heat at a slow rate enabling the oscillations to continue for a long
period of time.
Michael Pupin, another leading electrical researcher at the turn of the century, noted in his autobiography:
Tesla's patents for electrical generators and motors were granted in the late 1880's.
1890's the large electric power industry, in the form of
Westinghouse and General Electric, came into being. With tens of
millions of dollars invested in plants and equipment, the industry
was not about to abandon a very profitable ten year old technology
for yet another new one.
At the end of the section in Century where he described his new generator he wrote:
Years later, in 1933, he was more pointed in his remarks about the introduction of his fuelless generator. In the Philadelphia Public Ledger of November 2nd, is an interview with Tesla under the headline "Tesla 'Harnesses' Cosmic Energy."
In it he was,
It has been nearly a century since Nikola Tesla claimed a radically new method for producing electricity. The need for the development of new resources is greater now than at the end of the last century.
overlooked inventions will make his vision of "increasing human
energy through the use of the sun's energy" become a reality.