Nikola Tesla (1856)
Nikola Tesla was born in 1856 in Austria-Hungary and emigrated to the U.S. in
1884 as a physicist. He pioneered the generation, transmission, and use of alternating
current (AC) electricity, which can be transmitted over much greater distances
than direct current.
Tesla patented a device to induce electrical current in a piece of iron (a rotor)
spinning between two electrified coils of wire. This rotating magnetic field
device generates AC current when it is made to rotate by using some form mechanical
energy, like steam or hydropower. When the generated current reaches its user
and is fed into another rotating magnetic field device, this second device becomes
an AC induction motor that produces mechanical energy. Induction motors run
household appliances like clothes washers and dryers. Development of these devices
led to widespread industrial and manufacturing uses for electricity.
The induction motor was only part of Tesla's overall conception. In a series
of history-making patents, he demonstrated a polyphase alternating-current system,
consisting of a generator, transformers, transmission layout, and motor and
lights. From the power source to the power user, it provided the basic elements
for electrical production and utilization. Our AC power system remains essentially
unchanged today.
In 1888, George Westinghouse, head of the Westinghouse Electric Company, bought
the patent rights to Tesla's system of dynamos, transformers and motors. Westinghouse
used Tesla's alternating current system to light the World's Columbian Exposition
of 1893 in Chicago. Then in 1896, Tesla's system was used at Niagara Falls in
the world's first large hydroelectric plant. The Tesla coil, invented in 1891,
is still used in radio and television sets, car starters, and a wide variety
of electronic equipment.
Tesla's work with radio-frequency waves laid the foundation for today's radio.
He experimented with wireless transmission of electrical power, and received
112 patents for devices ranging from speedometers to extremely efficient electrical
generators to a bladeless turbine still in use today. He suggested that it was
possible to use radio waves to detect ships (later developed as RADAR), and
his work with special gas-filled lamps set the stage for the creation of fluorescent
lighting.
Tesla was Thomas Edison's rival at the end of the 19th century - in fact, he
was more famous than Edison throughout the 1890's. His invention of polyphase
AC electric power earned him worldwide fame but not fortune. At his zenith his
circle of friends included poets and scientists, industrialists and financiers.
Yet Tesla died alone and almost penniless in a New York hotel room in 1943.
During his life, Tesla created a legacy of genuine invention that still fascinates
today. After his death, the world honored him by naming the unit of magnetic
flux density the "tesla."
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