A resistive potentiometric type transducer with contactless slide

Though conventional potentiometric type resistive transducers are simple to construct and use, they are not popular owing only to the fact that a sliding contact needs to be employed. In this paper, a potentiometric type resistive displacement transducer that uses a contactless slide is presented. A dedicated signal conditioning circuit proposed here operates on the output of a slide that moves, without having a physical contact, on the resistive element and provides an output voltage directly proportional to the quantity being sensed (displacement or velocity). Since the output of the circuit is dependent only on a dc reference voltage and the measurand, an acceptable level of accuracy can be obtained with ease. Results of simulation studies and experimentation establish the efficacy of the proposed scheme.