| 摘要 |
PROBLEM TO BE SOLVED: To provide an echo canceller circuit which allows a transmitter and a receiver to be installed in the same place or closely to each other, and ensures a stable two-way talking without causing oscillation or echo between the transceivers of two communication apparatus. SOLUTION: One communication apparatus 1 has a plurality of speakers SP1, SP2 or earphones at its receiver 11, and a plurality of second amplifier circuits A2, A3 connected to these speakers or earphones are disposed separately from an amplifier circuit A1. A distributor circuit 12 distributes and sets the level of received signal voltages fed from a transmission system 18 to these second amplifiers A2, A3 after being amplified by the amplifiers, so that the levels of the received signal voltages given to one and the other amplifier circuits A2, A3 are always not equal but unbalanced and the output voltage of a microphone MIC1 is minimum. COPYRIGHT: (C)2005,JPO&NCIPI |
