Patents by Inventor Roger B. J. Hamel

Roger B. J. Hamel has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Anti-larsen-effect arrangement in a telephone station equipped with a loudspeaker
    Patent number: 4484034
    Abstract: An anti-Larsen circuit for a telephone station in which the listening channel comprises an automatic listening level control circuit, suitably of the type comprising a variable attenuator circuit, a pulse-width modulator and a threshold detector which supplies compression pulses. The transmission channel comprises a circuit for rendering the transmission channel operative or inoperative and also a control circuit. Actuation takes place above a sound-level threshold S.sub.1 and a de-activation below a sound-level threshold S.sub.2 which is smaller than S.sub.1.
    Type: Grant
    Filed: June 7, 1983
    Date of Patent: November 20, 1984
    Assignee: Telecommunications Radioelectrique et Telephoniques
    Inventors: Gilbert M. M. Ferrieu, Roger B. J. Hamel, Emmanuel Lefort, Francoise Moliere