| abstract |
A proximity sensor system uses a sensor coil as the frequency determining element of an oscillator circuit. The frequency of the oscillator circuit is thus modulated based on the proximity of the sensor coil to a conductive element, thereby supplying a frequency modulated sensor signal. A frequency modulation (FM) detector circuit demodulates the sensor signal, and supplies a signal having an amplitude that varies with, and is representative of, the proximity of the sensor coil to the conductive element. |