Nikola Tesla (Serbian Cyrillic: Никола Тесла; 10 July 1856 – 7 January 1943) was a Serbian-American inventor, electrical engineer, mechanical engineer, physicist, and futurist best known for his contributions to the design of the modern alternating current (AC) electrical supply system.
Tesla started working in the telephony and electrical fields before emigrating to the United States in 1884 to work for Thomas Edison. He soon struck out on his own with financial backers, setting up laboratories/companies to develop a range of electrical devices. His patented AC induction motor and transformer were licensed by George Westinghouse, who also hired Tesla as a consultant to help develop an alternating current system. Tesla is also known for his high-voltage, high-frequency power experiments in New York and Colorado Springs which included patented devices and theoretical work used in the invention of radio communication, for his X-ray experiments, and for his ill-fated attempt at intercontinental wireless transmission in his unfinished Wardenclyffe Tower project.
Tesla's achievements and his abilities as a showman demonstrating his seemingly miraculous inventions made him world-famous. Although he made a great deal of money from his patents, he spent a lot on numerous experiments over the years. In the last few decades of his life, he ended up living in diminished circumstances as a recluse in Room 3327 of the New Yorker Hotel, occasionally making unusual statements to the press. Because of his pronouncements and the nature of his work over the years, Tesla gained a reputation in popular culture as the archetypal "mad scientist". He died penniless and in debt on 7 January 1943.
Tesla's work fell into relative obscurity after his death, but since the 1990s, his reputation has experienced a comeback in popular culture. In 2005, he was listed amongst the top 100 nominees in the TV show The Greatest American, an open access popularity poll conducted by AOL and The Discovery Channel. His work and reputed inventions are also at the center of many conspiracy theories and have also been used to support various pseudosciences, UFO theories and New Age occultism.
In 1960, in honor of Tesla, the General Conference on Weights and Measures for the International System of Units dedicated the term "tesla" to the SI unit measure for magnetic field strength.
In 1891, Tesla patented the Tesla coil.
Working for Edison
In 1882, Tesla began working for the Continental Edison Company in France, designing and making improvements to electrical equipment.
In June 1884, Tesla relocated to New York City. During his trip across the Atlantic, his ticket, money, and some of his luggage were stolen, and he was nearly thrown overboard after a mutiny broke out on the ship. He arrived with only four cents in his pocket, a letter of recommendation, a few poems, and the remainder of his belongings.
In the letter of recommendation from Charles Batchelor, a former employer, to Thomas Edison, it is claimed that Batchelor wrote, "I know two great men and you are one of them; the other is this young man." (The exact contents of the letter are disputed in McNichol's book.) Edison hired Tesla to work for his Edison Machine Works. Tesla's work for Edison began with simple electrical engineering and quickly progressed to solving some of the company's most difficult problems. Tesla was even offered the task of completely redesigning the Edison Company's direct current generators.
In 1885, Tesla claimed that he could redesign Edison's inefficient motor and generators, making an improvement in both service and economy. According to Tesla, Edison remarked, "There's fifty thousand dollars in it for you—if you can do it"—this has been noted as an odd statement from an Edison whose company was stingy with pay and who did not have that sort of cash on hand. After months of work, Tesla fulfilled the task and inquired about payment. Edison, claiming that he was only joking, replied, "Tesla, you don't understand our American humor." Instead, Edison offered a US$10 a week raise over Tesla's US$18 per week salary; Tesla refused the offer and immediately resigned.
Middle years (1886-1899)
In 1886, Tesla formed his own company, Tesla Electric Light & Manufacturing. The company installed electrical arc light based illumination systems designed by Tesla and also had designs for dynamo electric machine commutators, the first patents issued to Tesla in the US.
Tesla proposed that the company should go on to develop his ideas for alternating current transmission systems and motors. The investors disagreed and eventually fired him, leaving him penniless; Tesla was forced to work as a ditch digger for US$2 per day. Tesla considered the winter of 1886/1887 as a time of "terrible headaches and bitter tears". During this time, he questioned the value of his education.
In April 1887, Tesla started a company, the Tesla Electric Company, with the backing of New York attorney Charles F. Peck and Alfred S. Brown, the director of Western Union. They set up a laboratory for Tesla at 89 Liberty St. in Manhattan so he could work on his alternating current motor and other devices for power distribution, with an agreement that they share fifty-fifty with Tesla any profits generated from patents. It was here in 1887 that Tesla constructed a brushless alternating current induction motor, based on a rotating magnetic field principle he claimed to have conceived of in 1882. He received a US patent for the motor in May 1888. At that time many inventors were trying to develop workable AC motors because AC's advantages in long distance high voltage transmission were counterbalanced by the inability to operate motors on AC. The rotating magnetic field induction motor seems to have been an independent invention by Tesla but it was not a unique discovery at the time. Italian physicist Galileo Ferraris published a paper on rotating magnetic field based induction motor on 11 March 1888, a working model of which he may have been demonstrating at the University of Turin as early as 1885. In 1888, a month before Tesla demonstrated his AC induction motor, Westinghouse engineer Oliver B. Shallenberger invented an induction meter that was based on the same rotating magnetic field principle and during Tesla's demonstration English engineer Elihu
Thomson stated he was working on an induction motor.
In 1888, the editor of Electrical World magazine, Thomas Commerford Martin (a friend and publicist), arranged for Tesla to demonstrate his alternating current system, including his induction motor, at the American Institute of Electrical Engineers (now IEEE). Engineers working for the Westinghouse Electric & Manufacturing Company reported to George Westinghouse that Tesla had a viable AC motor and power system—something that Westinghouse had been trying to secure. In July 1888 Brown and Peck negotiated a licensing deal with George Westinghouse for Tesla's polyphase induction motor and transformer designs for $60,000 in cash and stock and a royalty of $2.50 per AC horsepower produced by each motor. Westinghouse also hired Tesla for one year for the large fee of $2,000 a month to be a consultant at the Westinghouse Electric & Manufacturing Company's Pittsburgh labs.
During that year, Tesla worked in Pittsburgh, helping to create an alternating current system to power the city's streetcars. He found the time there frustrating because of conflicts between him and the other Westinghouse engineers over how to best implement AC power. Between them they settled on a 60-cycle AC current system Tesla proposed (to match the working frequency of Tesla's motor), although they soon found that, since Tesla's induction motor could only run at a constant speed, it would not work for street cars. They ended up using a DC traction motor instead.
Tesla demonstrated wireless energy transmission (Tesla effect) as early as 1891.
The Tesla coil is one of Nikola Tesla's most famous inventions. It is essentially a high-frequency air-core transformer. It takes the output from a 120vAC to several kilovolt transformer & driver circuit and steps it up to an extremely high voltage. Voltages can get to be well above 1,000,000 volts and are discharged in the form of electrical arcs. Tesla himself got arcs up to 100,000,000 volts, but I don't think that has been duplicated by anybody else. Tesla coils are unique in the fact that they create extremely powerful electrical fields. Large coils have been known to wirelessly light up florescent lights up to 50 feet away, and because of the fact that it is an electric field that goes directly into the light and doesn't use the electrodes, even burned-out florescent lights will glow.
Source : Wikipedia