| 摘要 |
A transducer for converting a pressure variation to a variation in the frequency of a periodic function includes a reference oscillator and a sensor oscillator coupled to a digital mixer. The reference oscillator includes a reference capacitor and reference resistor for providing a reference periodic electrical signal having a frequency which is a function of the reference timing capacitor and reference resistor. Similarly, the sensor oscillator has a variable sensor timing capacitor and a sensor resistor for providing a sensor periodic electrical signal having a frequency which is a function of the variable sensor timing capacitor and sensor resistor. The digital mixer generates a mixed periodic electrical signal having a frequency proportional to the difference between the reference and sensor electrical signals. The transfer function of the transducer relates pressure and frequency and is adjustable by adjustment of the magnitude of the reference and sensor resistors.
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