| 摘要 |
<p>According to the invention, a capacitive detector includes the following: a capacity sensor; a measuring transducer including a Schmitt trigger connected to an integrator; an amplifier; and a demodulator. The output of the integrator is connected to the input of the Schmitt trigger and, through a measuring capacitor of the sensing element, to a current amplifier. The reference capacitor of the sensor works as an integrating capacitor of the integrator. The output of the current amplifier is coupled to the input of the demodulator, whereby the control input of the latter is coupled to the output of the Schmitt trigger. The capacitive detector works as a transducer transforming linear displacement, humidity, level or tilt angle into a capacity signal. The direct current at the output is positively related to the ratio of the capacity of the measuring capacitor to the capacity of the reference capacitor. If the capacity sensor is differential, the output signal of the measuring transducer is positively related to the ratio between the differences of capacity of the measuring capacitors and of capacity of the reference capacitor.</p> |
