Noun
carbon microphone (plural carbon microphones)
A microphone containing carbon granules, whose electrical resistance varies with pressure.
After protracted patent litigation, in 1892 a federal court ruled that Edison and not Emile Berliner was the inventor of the carbon microphone. Source: Internet
In 1879, the Bell company acquired Edison's patents for the carbon microphone from Western Union. Source: Internet
In 1878, David E. Hughes noticed that sparks could be heard in a telephone receiver when experimenting with his carbon microphone. Source: Internet
Modulation is done by the large carbon microphone (cone shape) in the antenna lead. Source: Internet
Modulation was usually accomplished by a carbon microphone inserted directly in the antenna or ground wire; its varying resistance varied the current to the antenna. Source: Internet
The carbon microphone was also used in radio broadcasting and public address work through the 1920s. Source: Internet