| 摘要 |
PURPOSE:To make a CATV center detect the service life of a battery regularly. CONSTITUTION:The CATV center prepares power source monitoring control data to monitor the service life of a battery 19, and transmits it as a frequency division multiplex signal to a power source supplier 1. A control circuit 17 of the power source supplier 1, in a state which a commercial AC voltage is not turned OFF, by the power source monitoring control data to monitor the service life of the battery 19, supplies a switching signal g1 of a high level to a switch 31 and turns the switch 31 to an OFF state. When the switch 31 is turned to the OFF state, a DC voltage is not supplied from a charging circuit 18 to the battery 19 so that the voltage value of a voltmeter 22 starts to lower immediately after the commercial AC voltage is turned OFF and becomes 0V after a prescribed time. The CATV center can detect and discriminate the service life of the battery by detecting the relation between a voltage drop and the time by the voltage value of the voltmeter 22. |
