| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize full duplex audio communication without electrical feedback by sampling audio transmission and a received signal respectively by first and second pulses in a time-division manner so as to transmit/receive with fast switching. SOLUTION: After pulse generation circuits 15, 16 and analog switching circuits 11 to 14 operate and a received signal R from the receiving part of a communication equipment main body 200 is amplified by an operational amplifier circuit 17, its audio signal is sampled for each 110μs with the second pulse V1 equal to or shorter than the pulse width 1μs of an ON period by a second analog switch circuit 12, and converted by a transducer 10 to output voice. On the other hand, voice is detected by the transducer 10 with vibration at an ear as voice input, converted to an audio signal and the transmission signal is sampled for each 10μs with the first pulse V2 equal to or shorter than the pulse width 1μs of the ON period by a first analog switch circuit 11 to be inputted to an operational amplifier 18.</p> |
