A brilliant visionary and inventor, George Westinghouse developed alternating current (AC) for light and power. Although he was a college dropout, he filed more than 360 patents and started 60 companies, including Pittsburgh-based Westinghouse Electric Corp. Among his inventions were the gas turbine engine and electric locomotive as well as the electrical transformers that enabled the large-scale electrification of cities and the development of nuclear-powered ships. It was Westinghouse's radar that detected Japanese planes converging on Pearl Harbor -- although too late to avoid catastrophe. And he was also responsible for the first commercial radio broadcast on CBS, in Pittsburgh in 1924.

Born in Central Bridge, N.Y., in 1846, Westinghouse was the eighth of 10 children. When his family moved to Schenectady, his father opened a shop for agricultural machinery and small steam engines, giving George the opportunity to work with machinery.

When he was 20, he was on a train that violently stopped to avoid an oncoming locomotive, resulting in many injured passengers. He developed a method of using brakes actuated by compressed air that became a worldwide standard and founded the Westinghouse Air Brake Company in 1869. With the increase in rail traffic and development of railroad yards, he recognized the need for better signaling devices and interlocking switches and founded the Union Switch and Signal Company in 1881. A well drilled in the yard of his home in Pittsburgh led to several dozen inventions for the control and distribution of natural gas as well as a company to distribute gas.

His work then focused on a better distribution system for electric current. He had invented a reduction valve, which permitted high-pressure gas from the well to be delivered at low pressure at the point of use. He believed a similar device could work with electricity, so he turned a secondary generator developed in England into a transformer. This was the key to widespread distribution of electric power.

By the mid-1880s, he was pushing an AC delivery system that could be transmitted for miles; generators could be bigger and built out of town. Westinghouse began competing with Thomas Edison for the franchise in dozens of cities. The contest between the stubborn tycoon-inventors has been called "the War of the Currents" and played an important role in developing the electric chair.

Edison favored direct current (DC) as an energy source. Westinghouse believed AC was cheaper, more efficient and did not require the thick copper wiring DC current needed for conduction. However, when Edison realized that AC could be fatal, he sought to discredit his business rival Westinghouse.

Despite Edison's attempts, in just 10 years the value of the AC system had been demonstrated. Westinghouse teamed with Nikola Tesla (1857-1943) and bought the patent for the polyphase induction motor, which made his AC system unique. It debuted in Colorado in 1891, where a power plant using a 100-horsepower Westinghouse alternator sent electricity 2.6 miles to a motor-driven mill. In 1893, the Westinghouse Electric Co. lit the first Columbia Exposition in Chicago and in 1895 harnessed the Niagara Falls to generate electricity for the lights of Buffalo, NY, 22 miles away. Westinghouse Electric made the world's biggest electrical generators, employing more than 20,000 during World War II. Westinghouse died in 1914.