One of Tesla's greatest achievements, one that has revolutionized the world, is the Alternating Current (AC).  Thomas Edison was crazy about using Direct Current (DC), which is a current with the same amount of amperage at every point of time. This however was incredibly inefficient over long distances. Edison's vision of using DC power to deliver electricity to the world required that a power plant be built every square mile due to the inefficiencies of DC electricity. Alternating Current, by definition is a current that alternates it's direction of movement in a sinusoidal fashion many times a second, typically around 60 hz. Below is an example of  AC versus DC.



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    In 1887, Tesla patented his polyphase AC induction motor and transformers. After he did this, George Westinghouse, a famous entrepreneur and  industrialist, helped to fund Tesla's company, the Tesla Electric Company.  Doing so drove a war against Edison and his famed Direct Current. Westinghouse also bought Tesla's patents for $60,000 and for stock's in the Westinghouse Corporation.  Soon, Tesla would transform the world more so with the Tesla Coil.

The Early Years

Alternating Current

Tesla Coil

Bibliography