| 摘要 |
<p>PURPOSE:To simplify installation, to reduce them cost and to simplify setting of a threshold value of a detecting circuit by putting a sensor main body directly on a floor and by resetting the threshold value by turning ON or OFF a reset circuit. CONSTITUTION:A sensor main body 2 is put directly on a floor and employed. On the occasion, a flat-plate electrode 5 is protected by a sheet-like insulating material 6 so that an electrical characteristic be maintained. In a detecting circuit 8, a wave-detecting circuit 9 detects a transmission signal outputted from the main body 2, as a DC voltage, and an A/D converter 10 converts this voltage into a digital value by a conversion signal from CPU 12 and outputs it to the CPU 12. When a reset circuit 11 is turned ON, the CPU 12 erases stored data on each occasion. When the circuit 11 is turned OFF, the CPU stores output data of the converter 10, sets a threshold value afresh, compares the threshold value with an output of the converter 10 inputted sequentially and outputs the result of comparison. When a desk or the like is placed on the main body 2, for instance, a voltage obtained by detecting this body to be detected is stored, a threshold level is raised, and the circuit 8 can detect a human body even in the state of the desk or the like being placed.</p> |
