Design of digital type inductance sensor

The inductance sensor is often used for the measurement of displacement, pressure because of its simple structure, reliability and high precision. Usually the inductance sensor adopts AC electric bridge as its converting circuit to turn the sensor's inductance into an AC voltage signal. So it is difficult to make digital processing directly for the user. This paper introduces a converting circuit with digital interface. This circuit can turn the inductance signal produced by the inductance sensor into a RS232 serial digital signal. In addition, this circuit can provide exciting power independently and the extra exciting power is not needed, so it makes the application of the sensor simple. The inductance sensor equipped with this converting circuit can realize the digital output of the measured quantity. To the inductance sensor of different type, only little parameters of the circuit's software need to be modified, so this digital type inductance sensor has a higher practicality.