公开(公告)号：US4700382A

公开(公告)日：1987-10-13

申请号：US835588

申请日：1986-03-03

申请人： Donald R. Means ,  Robert C. True ,  Noble E. Wickliff

发明人： Donald R. Means ,  Robert C. True ,  Noble E. Wickliff

IPC分类号： H04M9/08 ,  H04M1/60

CPC分类号： H04M9/08

摘要： A voice-switched telephone circuit with center idle state improves bi-dirional gain control in loudspeaking telephones and thereby enhances the natural quality of interactive conversation. The voice-switched telephone includes: a transmit channel having a microphone and a three-state amplifier; a receiver channel having a three-state amplifier and a loudspeaker; and a hybrid circuit interconnecting the transmit and receive channels to a two-wire telephone line. The present invention is characterized by independent signal level detecting circuits for the transmit and receive channels. When the magnitude of the signal energy in the transmit channel exceeds a predetermined threshold, the transmit channel amplification is increased and the receive channel amplification is decreased by fixed equal amounts. When the magnitude of the signal energy in the receive channel from the two-wire telephone line exceeds a predetermined threshold, the receive channel amplification is increased and the transmit channel amplification is decreased by fixed equal amounts.

摘要翻译： 具有中心空闲状态的语音交换电话电路改善了扬声电话中的双向增益控制，从而提高了互动对话的自然质量。 语音交换电话包括：具有麦克风和三态放大器的发送信道; 具有三态放大器和扬声器的接收器通道; 以及将发送和接收信道互连到双线电话线路的混合电路。 本发明的特征在于用于发射和接收信道的独立信号电平检测电路。 当发送信道中的信号能量的大小超过预定阈值时，发送信道的放大增加，并且接收信道的放大减少固定的等量。 当来自两线电话线的接收信道中的信号能量的大小超过预定阈值时，接收信道放大增加，传输信道放大减少固定的等量。