Successive Approximation Type Direct Displacement to Digital Converter Suitable for Floating-Wiper Resistive Displacement Sensor
Aparna Mohan, Mohanasankar Sivapraskasam, Kumar V Jagadeesh · 2019
A novel signal conditioning circuit that operates on a floating wiper resistive displacement sensor and provides a digital output proportional to the displacement of the wiper is presented here. Floating wiper resistive displacement sensors possess long operational life due to reduced wear and tear as the wiper does not rub against the resistive element. However, the air gap between the floating wiper and the resistance introduces a coupling capacitance whose value varies as the wiper moves, making it difficult to obtain an output proportional to the displacement of the wiper. The successive approximation logic-based method presented here, operates on a floating wiper resistive displacement sensor and provides a digital output that is linear to the displacement of the wiper. More importantly the output is independent of the value of coupling capacitance. The efficacy of the scheme has been established through simulation studies, the results of which are also presented here.