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The World Wireless System was a turn of the 20th century proposed telecommunications and electrical power delivery system designed by inventor Nikola Tesla based on his theories of using Earth and its atmosphere as electrical conductors. He claimed this system would allow for "the transmission of electric energy without wires" on a global scale [1] as well as point-to-point wireless telecommunications and broadcasting. He made public statements citing two related methods to accomplish this from the mid-1890s on. By the end of 1900 he had convinced banker J. P. Morgan to finance construction of a wireless station (eventually sited at Wardenclyffe) based on his ideas intended to transmit messages across the Atlantic to England and to ships at sea. His decision to change the design to include wireless power transmission to better compete with Guglielmo Marconi's new radio based telegraph system was met with Morgan's refusal to fund the changes. The project was abandoned in 1906, never to become operational.
During this period Tesla filed numerous patents associated with the basic functions of his system, including transformer design, transmission methods, tuning circuits, and methods of signaling. He also described a plan to have some thirty Wardenclyffe-style telecommunications stations positioned around the world to be tied into existing telephone and telegraph systems. He would continue to elaborate to the press and in his writings for the next few decades on the system's capabilities and how it was superior to radio-based systems.
Despite claims of having "carried on practical experiments in wireless transmission", [2] there is no documentation he ever transmitted power beyond relatively short distances and modern scientific opinion is generally that his wireless power scheme would not have worked.
Tesla's ideas for a World Wireless system grew out of experiments beginning in the early 1890s after learning of Hertz's experiments with electromagnetic waves using induction coil transformers and spark gaps. [6] [7] He duplicated those experiments and then went on to improve Hertz's wireless transmitter, developing various alternator apparatus and his own high tension transformer, known as the Tesla coil. [8] [9] His primary interest in wireless phenomenon was as a power distribution system, early on pursuing wireless lighting. [10] From 1891 on Tesla was delivering lectures including " Experiments with Alternate Currents of High Potential and High Frequency " in 1892 in London and in Paris and went on to demonstrate "wireless lighting" [11] in 1893 [12] including lighting Geissler tubes wirelessly.
The first experiment was the operation of light and motive devices connected by a single wire to one terminal of a high frequency induction coil, performed during the 1891 New York City lecture at Columbia College. While a single terminal incandescent lamp connected to one of an induction coil's secondary terminals does not form a closed circuit "in the ordinary acceptance of the term" [13] the circuit is closed in the sense that a return path is established back to the secondary by capacitive coupling or 'displacement current'. This is due to the lamp's filament or refractory button capacitance relative to the coil's free terminal and environment; the free terminal also has capacitance relative to the lamp and environment.
The second result demonstrated how energy can be made to go through space without any connecting wires. The wireless energy transmission effect involves the creation of an electric field between two metal plates, each being connected to one terminal of an induction coil's secondary winding. A gas discharge tube was used as a means of detecting the presence of the transmitted energy. Some demonstrations involved lighting of two partially evacuated tubes in an alternating electrostatic field while held in the hand of the experimenter. [14]
While formulating his theories in the early 1890s Tesla discarded the idea of using radio waves. [15] He did not necessarily believe that radio waves existed as theorized by Maxwell, [15] [16] and he agreed with what most physicists were saying at the time: that radio waves would travel in a straight line in the same way that visible light travels, limiting their use for long-range communication. [17] (Radio waves do travel in a straight line, but this was many years before the discovery that the ionosphere would reflect certain radio waves making skywave communication of shortwave frequency bands possible over long distances.)
He believed that transmitting electrical signals beyond a line-of-sight distance would require the use of planet Earth as a conducting medium to overcome this limitation. [15] By the end of 1895, he made statements to the press about the possibility that "Earth's electrical charge can be disturbed, and thereby electrical waves can be efficiently transmitted to any distance without the use of cables or wires", and that the electrical waves can be used to transmit "intelligible signals" and "motive power." [18] On April 11, 1896, he stated that "messages might be conducted to all parts of the globe simultaneously" using electric waves "propagated through the atmosphere and even the ether beyond." [19] In September 1897 he applied for a patent [20] on a wireless power transmission scheme consisting of transmitting power between two tethered balloons maintained at 30,000 feet, an altitude where he thought a conductive layer should exist. [21]
Between 1895 and 1898, he constructed a large resonance transformer in his New York City lab called a magnifying transmitter to test his earth conduction theories. [22] In 1899 he carried out large scale experiments at Colorado Springs, Colorado. Based on his measurements there, he concluded that the Earth was "literally alive with electrical vibrations." He noted that lightning strikes indicate that the Earth is a large conductor with waves of energy traveling around it. He constructed a large magnifying transmitter measuring fifty-one feet (16 m) in diameter which could develop a working potential estimated at 3.5 million to 4 million volts and was capable of producing electrical discharges exceeding one hundred feet (30 m) in length. [23] With it he tested earth conduction and lit incandescent electric lamps adjacent to his lab in demonstrations of wireless power transmission.
Upon returning to New York City from Colorado Springs in 1900 he sought venture capitalists to fund what he viewed as a revolutionary wireless communication and electric power delivery system using the Earth as the conductor. By the end of 1900 he had gained the attention of financier J. P. Morgan who agreed to fund a pilot project (later to become the Wardenclyffe project) which, based on his theories, would be capable of transmitting messages, telephony, and even facsimile images across the Atlantic to England and to ships at sea. Morgan was to receive a controlling share in the company as well as half of all the patent income. Almost as soon as the contract was signed Tesla decided to scale up the facility to include his ideas of terrestrial wireless power transmission to better compete with Guglielmo Marconi's radio based telegraph system. [26] Morgan refused to fund the changes and, when no additional investment capital became available, the project at Wardenclyffe was abandoned in 1906, never to become operational.
Construction of the Wardenclyffe "wireless plant" in Shoreham started towards the end of 1901 and continued for the next three years. The plant included a Stanford White–designed 94 by 94 ft (29 by 29 m) brick building, a wood-framed tower 186 feet (57 m) tall with a 68 feet (21 m) in diameter "cupola" on top, and a 120 feet (37 m) shaft sunk into the ground with sixteen iron pipes driven "one length after another" 300 feet (91 m) below the shaft in order for the machine, in Tesla's words, "to have a grip on the earth so the whole of this globe can quiver". [27] [28] Funding problems continued to plague Wardenclyffe and by 1905-1906 most of the site's activity had to be shut down.
Through the latter part of the 1890s and during the construction of Wardenclyffe, Tesla applied for patents covering the many elements that would make up his wireless system. The system he came up with was based on electrical conduction with an electrical charge being conducted through the ground and as well as through a theorized conducting layer in the atmosphere. [29] [30] The design consisted of a grounded Tesla coil as a resonance transformer transmitter that he thought would be able to create a displacement of Earth's electric charge by alternately charging and discharging the oscillator's elevated terminal. This would work in conjunction with a second Tesla coil used in receive mode at a distant location, also with a grounded helical resonator and an elevated terminal. [31] [32] [33] He believed that the placement of a grounded resonance transformer at another point on the Earth's surface in the role of a receiver tuned to the same frequency as the transmitter would allow electric current to flow through the Earth between the two.
He also believed waves of electric current from the sending tower could be made to reflect back from the far side of the globe, resulting in amplified stationary waves of electric current that could be utilized at any point on the globe, localizing power delivery directly to the receiving station. Another aspect of his system was electricity returned via "an equivalent electric displacement" [34] in the atmosphere via a charged conductive upper layer that he thought existed, [21] [29] a theory dating back to an 1872 idea for a proposed wireless transmission-reception system developed by Mahlon Loomis. [35] The current was thought to be usable at the receiver for telecommunications, and to drive electrical devices. [32]
Tesla told a friend his plans included the building of more than thirty transmission-reception stations near major population centers around the world, [36] with Wardenclyffe being the first. If plans had moved forward without interruption, the Long Island prototype would have been followed by a second plant built in the British Isles, perhaps on the west coast of Scotland near Glasgow. Each of these facilities was to include a large magnifying transmitter of a design loosely based on the apparatus assembled at the Colorado Springs experimental station in 1899. [37]
Tesla's description of his wireless transmission ideas in 1895 includes its humanitarian uses in bringing abundant electrical energy to remote underdeveloped parts of the world, as well as fostering closer communications amongst nations. [38] In his June, 1900 Century Magazine article "The Problem of Increasing Human Energy", he elaborated on the properties of the Earth and on the principles of a system which could use the Earth as the medium for communication and the transmission of power without wires. He wrote that communications at any distance was practicable. He also noted this same process could be used to locate maritime objects such as icebergs or ships at sea and that "electrical movement of such magnitude" could communicate with other planets. [16]
In 1909 Tesla stated:
He also held beliefs that high potential electric current flowing through the upper atmosphere could make it glow, providing night time lighting for transoceanic shipping lanes. [35] [41]
He elaborated on World Wireless in his 1919 Electrical Experimenter article titled "The True Wireless", detailing its ability for long range telecommunications and putting forward his view that the prevailing theory of radio wave propagation was inaccurate. [15] [42]
Tesla's demonstrations of wireless power transmission at Colorado Springs consisted of lighting incandescent electric lamps positioned nearby the structure housing his large experimental magnifying transmitter, [43] with ranges out to 1,938 feet (591 m) from the transmitter. [25] There is little direct evidence of his having transmitted power beyond these photographically documented demonstrations. [44] [45] [46] [47] [48] [49] [50] [51] [52] He would claim afterwards that he had "carried on practical experiments in wireless transmission". [2] He believed that he had achieved Earth electrical resonance that, according to his theory, would produce electrical effects at any terrestrial distance. [53]
There have been varied claims over the years regarding Tesla's accomplishments with his wireless system. His own notes from Colorado Springs are unclear as to whether he was ever successful at long-range transmission. [54] Tesla made a claim in a 1916 statement to attorney Drury W. Cooper that in 1899, he collected quantitative transmission-reception data at a distance of about 10 miles (16 km). [55] Tesla biographer John J. O'Neill made a claim in his 1944 book Prodigal Genius: The life of Nikola Tesla that in 1899 at Colorado Springs, Tesla lit 200 incandescent lamps at a distance of 26 miles (42 km). [54] [56]
Scientist and engineers working in the field note that Tesla's ideas of transmitting large amounts of power long range would never have worked since he generally misunderstood the physics involved, over-estimated the conductivity of the Earth and the atmosphere, and vastly underestimated the loss of power over distance. [57] [45] [46] [51] [58] [59] [60] [61] [62]
Guglielmo Giovanni Maria Marconi, 1st Marquis of Marconi was an Italian inventor, electrical engineer, physicist, and politician, known for his creation of a practical radio wave–based wireless telegraph system. This led to Marconi being credited as the inventor of radio, and winning the 1909 Nobel Prize in Physics with Karl Ferdinand Braun "in recognition of their contributions to the development of wireless telegraphy". His work laid the foundation for the development of radio, television, and all modern wireless communication systems.
Nikola Tesla was a Serbian-American engineer, futurist, and inventor. He is known for his contributions to the design of the modern alternating current (AC) electricity supply system.
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A Tesla coil is an electrical resonant transformer circuit designed by inventor Nikola Tesla in 1891. It is used to produce high-voltage, low-current, high-frequency alternating-current electricity. Tesla experimented with a number of different configurations consisting of two, or sometimes three, coupled resonant electric circuits.
A communications system or communication system is a collection of individual telecommunications networks systems, relay stations, tributary stations, and terminal equipment usually capable of interconnection and interoperation to form an integrated whole. The components of a communications system serve a common purpose, are technically compatible, use common procedures, respond to controls, and operate in union.
Wardenclyffe Tower (1901–1917), also known as the Tesla Tower, was an early experimental wireless transmission station designed and built by Nikola Tesla on Long Island in 1901–1902, located in the village of Shoreham, New York. Tesla intended to transmit messages, telephony, and even facsimile images across the Atlantic Ocean to England and to ships at sea based on his theories of using the Earth to conduct the signals. His decision to increase the scale of the facility and implement his ideas of wireless power transmission to better compete with Guglielmo Marconi's radio-based telegraph system was met with refusal to fund the changes by the project's primary backer, financier J. P. Morgan. Additional investment could not be found, and the project was abandoned in 1906, never to become operational.
In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. The antenna intercepts radio waves and converts them to tiny alternating currents which are applied to the receiver, and the receiver extracts the desired information. The receiver uses electronic filters to separate the desired radio frequency signal from all the other signals picked up by the antenna, an electronic amplifier to increase the power of the signal for further processing, and finally recovers the desired information through demodulation.
Wireless power transfer is the transmission of electrical energy without wires as a physical link. In a wireless power transmission system, an electrically powered transmitter device generates a time-varying electromagnetic field that transmits power across space to a receiver device; the receiver device extracts power from the field and supplies it to an electrical load. The technology of wireless power transmission can eliminate the use of the wires and batteries, thereby increasing the mobility, convenience, and safety of an electronic device for all users. Wireless power transfer is useful to power electrical devices where interconnecting wires are inconvenient, hazardous, or are not possible.
A spark-gap transmitter is an obsolete type of radio transmitter which generates radio waves by means of an electric spark. Spark-gap transmitters were the first type of radio transmitter, and were the main type used during the wireless telegraphy or "spark" era, the first three decades of radio, from 1887 to the end of World War I. German physicist Heinrich Hertz built the first experimental spark-gap transmitters in 1887, with which he proved the existence of radio waves and studied their properties.
An Alexanderson alternator is a rotating machine, developed by Ernst Alexanderson beginning in 1904, for the generation of high-frequency alternating current for use as a radio transmitter. It was one of the first devices capable of generating the continuous radio waves needed for transmission of amplitude modulated (AM) signals by radio. It was used from about 1910 in a few "superpower" longwave radiotelegraphy stations to transmit transoceanic message traffic by Morse code to similar stations all over the world.
A single-wire transmission line is a method of transmitting electrical power or signals using only a single electrical conductor. This is in contrast to the usual use of a pair of wires providing a complete circuit, or an electrical cable likewise containing two conductors for that purpose.
The Tesla Experimental Station was a laboratory in Colorado Springs, Colorado, USA built in 1899 by inventor Nikola Tesla and for his study of the use of high-voltage, high-frequency electricity in wireless power transmission. Tesla used it for only one year, until 1900, and it was torn down in 1904 to pay his outstanding debts.
The invention of radio communication was preceded by many decades of establishing theoretical underpinnings, discovery and experimental investigation of radio waves, and engineering and technical developments related to their transmission and detection. These developments allowed Guglielmo Marconi to turn radio waves into a wireless communication system.
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Colorado Springs Notes, 1899–1900 (ISBN 8617073527) is a book compiled and edited by Aleksandar Marinčić and Vojin Popović detailing the work of Nikola Tesla at his experimental station in Colorado Springs at the turn of the 20th century.
Resonant inductive coupling or magnetic phase synchronous coupling is a phenomenon with inductive coupling in which the coupling becomes stronger when the "secondary" (load-bearing) side of the loosely coupled coil resonates. A resonant transformer of this type is often used in analog circuitry as a bandpass filter. Resonant inductive coupling is also used in wireless power systems for portable computers, phones, and vehicles.
The Tesla Science Center at Wardenclyffe is a nonprofit organization established to develop a regional science and technology center, museum and makerspace at the site of Nikola Tesla's former Wardenclyffe laboratory on Long Island, New York. The center had raised money through crowdfunding to purchase the property. In 2018, the Wardenclyffe site was listed on the National Register of Historic Places.
Nikola Tesla patented the Tesla coil circuit on April 25, 1891. and first publicly demonstrated it May 20, 1891 in his lecture "Experiments with Alternate Currents of Very High Frequency and Their Application to Methods of Artificial Illumination" before the American Institute of Electrical Engineers at Columbia College, New York. Although Tesla patented many similar circuits during this period, this was the first that contained all the elements of the Tesla coil: high voltage primary transformer, capacitor, spark gap, and air core "oscillation transformer".