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Tesla and wireless power transmission

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Nikola Tesla is one of the great scientists of the 20th century. He patented close to 300 inventions in electrical and mechanical engineering.

Many of Nikola Tesla’s inventions actually work. However, there are many urban legends surrounding his work, some of which have become the basis of conspiracy theories. Perhaps the most widely known is related to Tesla’s discovery that electrical power can be transmitted wirelessly, through the air, from one device to another.

Tesla demonstrated that some power from a Tesla coil could effectively be used to power light bulbs tens or hundreds of feet away. He then envisioned extending the power and range of these devices: he wanted to build a remote power station which could wirelessly power entire cities and towns.  However, Tesla never actually worked through the math to prove that this would be efficient or possible, nor did he even demonstrate this level of usefulness.

There is a belief that Tesla “proved” that these towers could wirelessly power cities, and that either the government, or power companies, conspired to keep the details of how this works secret. Electrical engineers and physicists, however, hold that not only is there no conspiracy, but that basic laws of physics show that Tesla’s proposal was unworkable in practice. Below you will find details on why it does not work for large geographical areas.

The information below has been excerpted & adapted from https://en.wikipedia.org/wiki/Wireless_power (1/29/16)

Also see “The Cult of Nikola Tesla”

nikola tesla

Inventor Nikola Tesla performed the first experiments in wireless power transmission at the turn of the 20th century. He has done more to popularize the idea than any other individual.  From 1891 to 1904 he experimented with transmitting power by inductive and capacitive coupling, using spark-excited radio frequency resonant transformers, now called Tesla coils, which generated high AC voltages. With these he was able to transmit power for short distances without wires.

Charles Dudley Arnold, Court of Honor, World's Columbian Exposition 1893

He found he could increase the distance by using a receiving LC circuit tuned to resonance with the transmitter’s LC circuit, using resonant inductive coupling.

At his Colorado Springs laboratory during 1899–1900, by using voltages of the order of 10 mega-volts generated by an enormous coil, he was able to light three incandescent lamps at a distance of about one hundred feet.

Tesla in Colorado  Photo by Dickenson V. Alley

The resonant inductive coupling which Tesla pioneered is now a familiar technology used throughout electronics and is currently being widely applied to short-range wireless power systems.

The inductive and capacitive coupling used in Tesla’s experiments is a “near-field” effect, so it is not able to transmit power long distances. However, Tesla was obsessed with developing a wireless power distribution system that could transmit power directly into homes and factories, as proposed in his visionary 1900 article in Century magazine.

He claimed to be able to transmit power on a worldwide scale, using a method that involved conduction through the Earth and atmosphere. Tesla believed that the entire Earth could act as an electrical resonator, and that by driving current pulses into the Earth at its resonant frequency from a grounded Tesla coil working against an elevated capacitance, the potential of the Earth could be made to oscillate, and this alternating current could be received with a similar capacitive antenna tuned to resonance with it at any point on Earth.

Future Tesla wireless power transmitter

Another of his ideas was to use balloons to suspend transmitting and receiving electrodes in the air above 30,000 feet (9,100 m) in altitude, where the pressure is lower. At this altitude, Tesla claimed, an ionized layer would allow electricity to be sent at high voltages (millions of volts) over long distances.

In 1901, Tesla began construction of a large high-voltage wireless power station, now called the Wardenclyffe Tower, at Shoreham, New York. Although he promoted it to investors as a transatlantic radiotelegraphy station, he also intended it to transmit electric power as a prototype transmitter for a “World Wireless System” that was to broadcast both information and power worldwide.

By 1904 his investors had pulled out, and the facility was never completed. Although Tesla claimed his ideas were proven, he had a history of failing to confirm his ideas by experiment, and there seems to be no evidence that he ever transmitted significant power beyond the short-range demonstrations above.

Ask a Question Research Hypothesis flowchart

The only report of long-distance transmission by Tesla is a claim – not found in reliable sources – that in 1899 he wirelessly lit 200 light bulbs at a distance of 26 miles (42 km). There is no independent confirmation of this putative demonstration; Tesla did not mention it, and it does not appear in his meticulous laboratory notes. It originated in 1944 from Tesla’s first biographer, John J. O’Neill, who said he pieced it together from “fragmentary material… in a number of publications”.

In the 110 years since Tesla’s experiments, efforts using similar equipment have failed to achieve long distance power transmission, and the scientific consensus is his World Wireless system would not have worked. Tesla’s world power transmission scheme remains today what it was in Tesla’s time, a fascinating dream.

Tesla’s Big Mistake. Amasci.com – William Beaty

The real science of non-Hertzian waves, By Paul Nicholson

Wireless Energy Transfer, By Yue Ma

Advanced materials

Wireless Power Transmission: From Far-Field to Near-Field

 

 

 

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