| 摘要 |
<p>A capacitance measuring circuit (10) comprising an AC voltage generator (11), a first operational amplifier (14) having a noninverted input terminal connected to a predetermined potential (in this example, to the ground), a second operational amplifier (16) constituting a voltage follower, a resistor (R1) (12) connected between the AC voltage generator (11) and the inverted input terminal of the first operational amplifier (14), a resistor (R2) (13) connected between the inverted output terminal of the first operational amplifier (14) and the output terminal of the second operational amplifier (16), and an impedance element (capacitor) (15) connected between the output terminal of the first operational amplifier (14) and the noninverted input terminal of the second operational amplifier (16), wherein a capacitor (17) to be measured is connected between the noninverted input terminal of the second operational amplifier (16) and a predetermined potential, and the capacitor measuring circuit (10) is provided in a position adjacent to the capacitor (17) to be measured.</p> |
