Nikola Tesla was an inventor.
Nikola Tesla ( Никола Тесла 10 July 1856 -- 7 January 1943 ) was a Serbian-American inventor , electrical engineer , mechanical engineer , physicist , and futurist who is best known for his contributions to the design of the modern alternating current ( AC ) electricity supply system . Attempting to develop inventions he could patent and market , Tesla conducted a range of experiments with mechanical oscillators/generators , electrical discharge tubes , and early X-ray imaging . After Wardenclyffe , Tesla went on to try and develop a series of inventions in the 1910s and 1920s with varying degrees of success .