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