| 摘要 |
<p>First and third current paths (101, 103) are connected to each other at their respective one ends (81), while second and fourth current paths (102, 104) are also connected to each other at their respective one ends (87). A transmitting unit (200) varies the current flowing through a path between the other ends (203, 204) of the first and second current paths (101, 102), thereby sending a signal that utilizes the current variation. A switching unit (300) causes, in response to the application of a control signal (SC) from a control unit (230), a path between the other end (301) of the third current path (103) and the other end (302) of the fourth current path (104) to be nonconductive. Conversely, the switching unit (300) causes, in response to the absence of the control signal (SC), the path between the other end (301) of the third current path (103) and the other end (302) of the fourth current path (104) to be conductive.</p> |
