| 摘要 |
An improved two loop capacitive sensor oscillator circuit converts a transducer capacitance to a frequency and includes a first loop to create an oscillatory waveform having a frequency related to a capacitance of the capacitive transducer. The first loop includes a resistor. The resistor is electrically coupled to a capacitor. The resistor is also electrically coupled to the capacitive transducer. The capacitive transducer is electrically coupled to an input of a first inverter gate. A second loop oscillates at the frequency of the first loop and further generates a second waveform of a substantially square wave shape at the same frequency. The second loop is electrically coupled to the first loop and the output of a third inverter gate is substantially a square wave at the frequency related to the capacitance of the capacitive transducer.
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