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Jules Cerpaux
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Individual
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Individual
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Publication of GB190007355ApublicationCriticalpatent/GB190007355A/en
7355. Cerpaux, J. April 20. Telephones. - Mi c r o - phones are constructed with the carbon granules c held in shouldered or cylindrical holes or recesses in a metal block a. The block n is preferably of silver - plated copper, and is secured to the case by a screw g. d is a metal backing plate, and e is an insulating-disc, the screw g being insulated by an ebonite bush f. k is the carbon diaphragm gripped between the front and back portions of the metal case, and t is a protective gauze screen.
GB190007355D1900-04-201900-04-20Improvements in Microphones.
ExpiredGB190007355A
(en)