Fessenden oscillator

Reginald Fessenden and Fessenden oscillator, around 1914
Design and photograph of a Fessenden oscillator, with copper cylinder, soft iron core, AC winding, DC coil and 1.9 cm thick steel diaphragm
Portrait photograph of Reginald Fessenden from Harper's Weekly Magazine, 1903

A Fessenden oscillator is an electro-acoustic transducer invented by Reginald Fessenden, with development starting in 1912 at the Submarine Signal Company of Boston.[1] It was the first successful acoustical echo ranging device. Similar in operating principle to a dynamic voice coil loudspeaker, it was an early kind of transducer, capable of creating underwater sounds and of picking up their echoes.

The creation of this device was motivated by the RMS Titanic disaster of 1912, which highlighted the need to protect ships from collisions with icebergs, obstacles, and other ships. Because of its relatively low operating frequency, it has been replaced in modern transducers by piezoelectric devices.

  1. ^ Frost, Gary Lewis (2001). "Inventing Schemes and Strategies: The Making and Selling of the Fessenden Oscillator". Technology and Culture. 42 (3): 462–488. doi:10.1353/tech.2001.0109. S2CID 110194817. Project MUSE 33762.