| 摘要 |
PROBLEM TO BE SOLVED: To provide an audio transmission control circuit which attains enhancement in economical efficiency and construction efficiency of a wiring quantity so as to realize a control signal line by laying around two wires for each speaker. SOLUTION: When transmitting audio signals from a broadcast sound source through an amplifier to speakers of a terminal via an audio transmission line, in an audio transmission part, the audio signal is digitized, a relay switch at the side of each speaker is selectively controlled in a time division multiplex manner under sequence control, and the audio signal is outputted to a digital signal transmission line via a selective relay switch. At the side of each speaker, a reception part which receives the digital signal time-compressed at the side of the audio transmission part via said common digital signal transmission line, and which applies time-expansion thereto, comprises a switch control part which recognizes a digital signal corresponding to the relevant speakers and controls said relay switch. COPYRIGHT: (C)2005,JPO&NCIPI |
