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Dynamic Microphone Invention

June 27th Fact-of-the-Day

The dynamic microphone was invented in 1877 by Curttris and Redding working together in the United States and by Ernst W. Siemens working independently in Germany. However, Siemens obtained a patent and is often cited as the inventor. Both the American and German designs consisted of a small, light-weight, electrically-conducting coil of wire mechanically attached to the frustum of a light-weight, cone-shaped diaphragm that vibrated in sympathy with sound waves propagating through air. In both designs the coil was positioned within a strong permanent-magnet magnetic field so an alternating electric current was induced in the coil as the diaphragm vibrated. The first practical commercial dynamic microphone was the Western Electric 618-A introduced in the late 1920's. It was developed by Thuras and Wente. ©2005 Martek International All rights reserved.

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