| 摘要 |
PURPOSE:To supply efficiently power, by supplying a charging power to a slave station device with charging voltage decrease information of a power capacitor. CONSTITUTION:A 2-wire transmission line 30 is used in common for the supply of AC power and the transmission of a remote signal, and n-sets (40-1-40-n) of slave devices are connected. When a charging voltage of a capacitor C1 of the slave station device 40-1 is dropped to a specified voltage or below, a power supply voltage detecting circuit 43 inputs a voltage decrease signal 48 to a slave station signal processing circuit 41. Then, the processing circuit 41 adds the voltage decrease information to a remote signal SV and transmits the result to a master station device 20 via the transmission line 30. When the master station device 20 detects this voltage decrease information, the AC power is applied to a rectifying and smoothing circuit 42 of the slave station device via the transmission line 30. The capacitor C1 is charged with this output. Thus, the power is supplied efficiently. |
