摘要 |
<p>Non-contacting sensor apparatus having two tank circuits (12a, 16; 12b, 16) from which an indication of the position of the moving part of the sensor (14) is developed by measuring the relative resonance frequencies of the two tank circuits. As the moving part of the sensor (14) changes position, the relative resonance frequencies of the two tank circuits (12a, 16; 12b, 16) change. The outputs of the two tank circuits (12a, 16; 12b, 16) are multiplexed and drive a pulse generator (18) which develops a first series of pulses having a repetition rate which corresponds to the resonance frequency of one of the tank circuits (12a, 16; 12b, 16) and a second series of pulses having a repetition rate which corresponds to the resonance frequency of the other tank circuit (12a, 16; 12b, 16). The relative times required to count the same number of pulses of each series of pulses provides an indication of the position of the moving part of the sensor (14).</p> |