Ernst Alexanderson

Ernst Frederick Werner Alexanderson (Swedish: [ɛʂnt alɛkˈsandɛʂɔn]; January 25, 1878 – May 14, 1975) was a Swedish-American electrical engineer and inventor who was a pioneer in radio development. He invented the Alexanderson alternator, an early radio transmitter used between 1906 and the 1930s for longwave long distance radio transmission. Alexanderson also created the amplidyne, a direct current amplifier used during the Second World War for controlling anti-aircraft guns.