| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce output to a power line for unnecessary frequency band component without using an expensive, dedicated processing IC by constructing a simple system as a whole and to cut the cost, compared to a case using the dedicated processing IC. <P>SOLUTION: A microcomputer 6 for each lighting fixture 1 lights a lamp load 3 so long as a lighting holding timer 61 continues to count when a high level detection signal from a human detection sensor 5 or a control signals from other lighting fixtures 1 is inputted. Moreover, when the high level detection signal from the human detection sensor 5 is inputted, the microcomputer 6 generates a rectangular wave signal. A communicating part 7 extracts a basic frequency component from the rectangular wave signal by a filter 70 provided as an element separated, from the micro computer 6, amplifies the basic frequency component by an output amplifier 71 and transmits the basic frequency component to other lighting fixtures as the control signal 1 through a power line 2. The microcomputer 6 stops generation of the rectangular wave signal so long as a transmitting mask timer 62 continues to count after the rectangular wave signal is generated or after the control signal is inputted. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
