Circuit for a speech-controlled loudspeaking telephone station in telecommunication systems, especially telephone systems

摘要

Circuit arrangement for a voice-controlled According to telephone station in telecommunications, especially telephone systems with channel-specific amplifiers and with a speech direction detecting circuit, which in both channels so controlled in response to a voltage comparing attenuators that in the channel with the higher crosstalk voltage reduces the damping and in the channel with the lower crosstalk voltage the damping is increased accordingly.; The signal voltages derived from the microphone and speaker voltages are supplied to the rectifying devices each have operational amplifier. Thereby, the threshold voltage of the rectifier diodes is virtually eliminated so that strong control fluctuations can be controlled better on the connecting lines.