| 摘要 |
PURPOSE:To increase the power source capacity for a system as required by composing the system of an in-use/stand-by type call signal power source operating as a master equipment and that operating as a subordinate equipment. CONSTITUTION:As in-use unit 11a operates as a master equipment, a synchronizing signal is outputted from synchronizing signal output terminal M to synchronizing signal input terminal S of unit 11b, and stand-by unit 11b is operated synchronizing with unit 11a. The synchronizing signal of unit 11a is supplied to synchronizing signal input terminals S of in-use unit 12a and stand-by unit 12b of device 122 via OR circuit 151, and units 12a and 12b are operated synchronously. If unit 11a is troubled, a condition signal is outputted from condition signal generating circuit 14 and unit 11b operates as the master equipment. If unit 12a is troubled, on the other hand, change-over switch 132a turns off, and change-over switch 132b turns on, so that a call signal voltage will be outputted from unit 12b. |
