| 摘要 |
<p>PURPOSE:To provide an electrostatic sensor high in detection accuracy. CONSTITUTION:This sensor has a pulse signal generating circuit 21, an attenuator constituted of a resistor 51 and a detection electrode 41, a differential amplifier 31, an AC-DC converter 71, a switching means 3, and a correcting means 2a. The switching means 3 is constituted of switches 61 and 62, a pulse signal generating circuit 22, a comparator 34, and a power source 82. The correcting means 2a is constituted of a capacitor 42, a differential amplifier 33, a power source 81, and an amplifier 32. In the case where the switch 61 is connected to a terminal S1, a voltage Va5 of an output signal from the AC-DC converter 71 is kept at a fixed value. When the Va5 exceeds the threshold value, the switch 61 is connected to a terminal S2, so that the correcting means 2a does not operate.</p> |
