| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that, when transmitting power consumption states of a plurality of low-order (branch destination) electrical devices to a high-order (branch source) device, signals may be mixed (interfered) and it may be difficult to discriminate the signals in the high-order device.SOLUTION: Signal transmitters 18A-18C are provided in electrical devices 14A-14C and transmits AC signals to a recorder 20 via a power line 26, the AC signals including identification information identifying the electrical devices 14A-14C and current consumption value information detected by the current sensors 16A-16C. When transmitting the AC signals, the signal transmitters 18A-18C transmit the AC signals to the recorder 20 in such a manner that transmission timing becomes different. |
