Tesla - Middle Years (1886-1899)

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 Street 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.

In 1891, Tesla patented the Tesla coil.