Loudspeaker telephone circuit arrangement

Abstract

Abstract A LOUDSPEAKER TELEPHONE CIRCUIT ARRANGEMENT PROVIDING A HYBRID CIRCUIT COUPLED TO A TELEPHONE LINE, A MICROPHONE TRANSMISSION CHANNEL AND A LOUDSPEAKER RECEPTION CHANNEL COUPLED TO AN INPUT AND AN OUTPUT OF THE HYBRID CIRCUIT RESPECTIVELY, A CONTROL CIRCUIT COUPLED TO THE MICROPHONE CHANNEL AND THE LOUDSPEAKER CHANNEL FOR CONTROLLING THE TRANSMISSION TO AND RECEPTION FROM SAID TELEPHONE LINE RESPECTIVELY, A MICROPHONE SWITCHING AMPLIFIER AND A LOUDSPEAKER SWITCHING AMPLIFIER COUPLED BETWEEN THE CONTROL CIRCUIT AND THE MICROPHONE CHANNL AND BETWEEN THE CONTROL CIRCUIT AND THE LOUDSPEAKER CHANNEL RESPECTIVELY FOR BIASING THE CONTROL CIRCUIT IN OPPOSITE DIRECTIONS, AN ECHO DETECTOR COUPLED BETWEEN THE LOUDSPEAKER CHANNEL AND THE MICROPHONE SWITCHING AMPLIFIER TO PREVENT LOUDSPEAKER SIGNALS FROM BEING TRANSMITTED OUT ON THE TELEPHONE LINE, AND A BREAKTHROUGH MUTING CIRCUIT COUPLED BETWEEN THE HYBRID CIRCUIT AND THE LOUDSPEAKER SWITCHING AMPLIFIER TO PREVENT "BREAKTHROUGH" OF SIGNALS FROM SAID MICROPHONE CHANNEL TO THE LOUDSPEAKER CHANNEL VIA THE HYBRID CIRCUIT.

Inventors

• 👤 Arthur Herbert Patrick Baker

Bibliographic Details