War of the Currents: Direct Vs. Alternating Currents
“I believe there has been a systematic attempt on the part of some people to do a great deal of mischief and create as great a difference as possible between the Edison Company and The Westinghouse Electric Co., when there ought to be an entirely different condition of affairs.”-George Westinghouse
A rivalry between Thomas Edison, promoting direct current and Nikola Tesla, urging alternating current, (purchased by George Westinghouse) became prominent in the late 1800's. Edison went so far as to electrocute animals to make AC seem dangerous and had the first electric chair made with this system. Ultimately, the battle was won by Westinghouse in 1893, when his current was chosen for powering the World's Fair and Niagara Falls.
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"The special advantages of the polyphase plan over a single alternating current need not be pointed out here; but regarding the alternating current itself, whatever its phase, it should be said that it is peculiarly suited to transmission over long distances."- The New York Tribune (1895)
Development of Alternating Current
"The idea came like a flash of lightning and in an instant the truth was revealed. I drew with a stick on the sand the diagrams shown six years later in my address before the American Institute of Electrical Engineers [AIEE], and my companion understood them perfectly. The images were wonderfully sharp and clear and had the solidity of metal and stone, so much so that I told him: 'See my motor here; watch me reverse it.' I cannot begin to describe my emotions."-Nikola Tesla
Tesla had a revelation about AC motors in Budapest in 1881 but took until 1888 to patent them.
“Up to this time everyone who tried to make an alternating current motor used a single circuit…. What Tesla did was to use two circuits, each one carrying the same frequency of alternating current, but in which the current waves were out of step with each other. This was the equivalent of adding to an engine a second cylinder.” |
“It was the simplest motor I could conceive of. As you see it had only one circuit, and no windings on the armature or the fields. It was of marvelous simplicity.”- Nikola Tesla, (About 1st AC Motor)
Niagara Falls: The First Hydroelectric Power Plant
"A large contract for electrical machinery for the Niagara plant has been awarded to the Westinghouse Company, of Pittsburgh. The system which has been adopted is known as the Tesla polyphase. The present contract calls for three 5000 horse-power generators, with a corresponding equipment of motors, switches, etc. The rotating fields are carried on the upper ends of vertical shafts, and thus coupled direct to turbines. The upward pressure of the water supports the entire weight of the turbines, shafts, and rotating parts of the generators, thus doing away with nearly all the step-friction. The electromotive force of the dynamos will be from 2000 to 2400 volts...The system adopted would seem to provide for every possible requirement of an electric service, either in the way of illumination or power."-Franklin L. Pope, Engineering Magazine (1893)
“I told my uncle that I would go to America and carry out this scheme...thirty years later I saw my ideas carried out at Niagara.”-Nikola Tesla |