Many people today are not familiar with the device or why we need such a device. Today we can use vacuum tubes or solid state technology to amplify electric signal, but in the time of Alexanderson those tools were not available. In John S. Stone of American Bell Telephone came up with the idea of using a high frequency alternator a rapidly spinning disk to act as a repeater to amplify signal. He needed to boost telephone signals to cross great distances with copper wire.
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Alexanderson, IRE President, , invented a self-exciting alternator. He also designed a series of high-frequency alternators for radio use.
He spent a year taking advanced studies in electrical engineering in Germany before coming to the United States. One of his first inventions was a self-exciting alternator which was the subject of a paper published by the American Institute of Electrical Engineers AIEE in Subsequently, he devised a modified repulsion motor for electric railway use, which he described in a AIEE paper. Alexanderson Alternator Dr.
Ernst F. Alexanderson, GE communications pioneer, has been inducted into the National Inventors Hall of Fame in Arlington, VA in recognition of his work on the high frequency alternator.
This historical photograph, taken in , shows the late Dr. Alexanderson inspecting one of the high frequency alternators that gave America its start in the field of radio communication. This alternator, one of several designed by him from to was used to send transatlantic radio-telegraph messages from Rocky Point, Long Island.
Beginning in , Alexanderson designed a series of high-frequency alternators for use in radio as sources of transmitter power which provided an alternative to spark and arc transmitters. One of his early radio alternators was employed by Reginald Fessenden for experiments with voice and music broadcasts from a station in Brant Rock , MA, in December A later and higher-powered radio alternator capable of 50 kW output designed by Alexanderson was installed in New Brunswick, NJ, in and used for transatlantic communication during World War I.
The first of several kW Alexanderson radio alternators was located at the New Brunswick station in and served as the prototype for a long-wave radio network established by the Radio Corporation of America RCA following its formation in He became the second recipient of the IRE Medal of Honor in in recognition of his contributions to global radio communication.
He was president of the IRE during In August Alexanderson published a paper in the Proceedings of the IRE, where he noted that it already had "become generally known that a new highway for world traffic has been opened up through the development of transatlantic radio communication. He provided some technical information on the kW radio alternator, the magnetic amplifier, and a multiple antenna which were key elements of his long-wave system.
He demonstrated television in the home in using a rotating disk type receiver. He also studied and made inventions relating to electronic power conversion, direct-current power transmission, and gun-control systems.
During World War II, he worked on analog computers for use with radar and developed military applications of the amplidyne. Alexanderson retired from GE in although he continued as a consultant to the company for several more years. His numerous inventions and other achievements gained him recognition as one of the most outstanding members of the electrical engineering profession during a career of over a half century. He received more than United States patents, with the final one issued when he was Alexanderson died in at age
Ernst F. W. Alexanderson
Navy recognized the need for reliable distant longwave VLF transmissions to the Pacific fleet. A new facility was constructed at Haiku in Hawaii, where two KW Alexanderson alternators transferred from the mainland were installed. The Navy also operated an existing transmitter at Bolinas, California, again for Pacific ocean communication. The Air Force found that longwave transmissions were more reliable than shortwave when sending weather information to Arctic researchers as well as bases in Greenland, Labrador, and Iceland. The two Marion transmitters were used until
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Flowers Inventor, Engineer. He is best remembered as a pioneer in the field of television and voice radio broadcasting. While there, he became interested in alternating current phenomena after reading a book on the subject by Dr. He decided to emigrate to the US to meet Steinmetz and seek work with him, which he did in He had been employed at GE for only a short period of time when it received an order from Canadian-born professor and researcher Reginald Fessenden for an alternator with much higher frequency than others in existence at that time. By the fall of that year, its output had been improved to watts and 75 kHz.
Ernst F.W. Alexanderson
Alexanderson, IRE President, , invented a self-exciting alternator. He also designed a series of high-frequency alternators for radio use. He spent a year taking advanced studies in electrical engineering in Germany before coming to the United States. One of his first inventions was a self-exciting alternator which was the subject of a paper published by the American Institute of Electrical Engineers AIEE in