| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide: an electric power supply tap for transmitting and receiving data while reducing cost and preventing generation of noise and/or harmonic; a terminal device; and a communication system. <P>SOLUTION: This invention refers to the electric power supply tap 100, having a channel 1 not including a resistor R1 and a channel 2 including the resistor R1, a control circuit 14 and triacs T1, T2, and a current sensor 52, wherein the supply tap supplies alternating current to a terminal device 200 and is connected to the terminal device 200 to make up a closed circuit, and an alternating current runs through either the channel 1 or 2 to transmit/receive data to/from the terminal device 200. The control circuit 14 and the triacs T1, T2 choose either the channel 1 or 2 based on the data in accordance with a cycle of an amplitude of the alternating current to be "0" when transmitting the data to the terminal device 200, and the current sensor 52 detects a change of the amplitude based on the data when receiving the data from the terminal device 200. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
