| 摘要 |
PURPOSE:To reduce power consumption remarkably by applying a power supply of a high efficiency coding decoding section in a line adaptor only to a terminal line in operation. CONSTITUTION:An audio signal sent from terminal equipments 201-203 is processed by line adaptors 401-403 corresponding to a multiplexer 101 via terminal lines 301-303, multiplexed by a multiplex section 801 and sent through a high speed multiplex line 901. An incoming call is similarly processed. The line adaptors 401-403 monitor the operating state of the lines 301-303 provided with line monitor sections 601-603 and power application to high efficient coding decoding sections 501-503 is applied to only the lines 301-303 in operation by using power supply control sections 701-703. The power consumption is remarkably reduced through the circuit configuration that not only power is interrupted to a line adaptor corresponding to a terminal line not actually in use but also power is interrupted to a line adaptor corresponding to a terminal line in use when the line adaptor is not in use at present. |
