Alexanderson, Ernst Frederik Werner

SUBJECT AREA: Broadcasting, Electricity, Electronics and information technology, Telecommunications

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b. 25 January 1878 Uppsala, Sweden

d. ? May 1975 Schenectady, New York, USA

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Swedish-American electrical engineer and prolific radio and television inventor responsible for developing a high-frequency alternator for generating radio waves.

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After education in Sweden at the High School and University of Lund and the Royal Institution of Technology in Stockholm, Alexanderson took a postgraduate course at the Berlin-Charlottenburg Engineering College. In 1901 he began work for the Swedish C \& C Electric Company, joining the General Electric Company, Schenectady, New York, the following year. There, in 1906, together with Fessenden, he developed a series of high-power, high-frequency alternators, which had a dramatic effect on radio communications and resulted in the first real radio broadcast. His early interest in television led to working demonstrations in his own home in 1925 and at the General Electric laboratories in 1927, and to the first public demonstration of large-screen (7 ft (2.13 m) diagonal) projection TV in 1930. Another invention of significance was the "amplidyne", a sensitive manufacturing-control system subsequently used during the Second World War for controlling anti-aircraft guns. He also contributed to developments in electric propulsion and radio aerials.

He retired from General Electric in 1948, but continued television research as a consultant for the Radio Corporation of America (RCA), filing his 321st patent in 1955.

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Principal Honours and Distinctions

Institution of Radio Engineers Medal of Honour 1919. President, IERE 1921. Edison Medal 1944.

Bibliography

Publications relating to his work in the early days of radio include: "Magnetic properties of iron at frequencies up to 200,000 cycles", Transactions of the American Institute of Electrical Engineers (1911) 30: 2,443.

"Transatlantic radio communication", Transactions of the American Institute of Electrical

Engineers (1919) 38:1,269.

The amplidyne is described in E.Alexanderson, M.Edwards and K.Boura, 1940, "Dynamo-electric amplifier for power control", Transactions of the American

Institution of Electrical Engineers 59:937.

Further Reading

E.Hawkes, 1927, Pioneers of Wireless, Methuen (provides an account of Alexanderson's work on radio).

J.H.Udelson, 1982, The Great Television Race: A History of the American Television Industry 1925–1941, University of Alabama Press (provides further details of his contribution to the development of television).

KF