Near Full Stroke Length Linear Range Enhancement Circuit for Linear Variable Differential Transformer (LVDT)

Abstract

This paper proposes a linear range enhancement circuit for Linear Variable Differential Transformer (LVDT). The nonlinear is compensated with a signal obtained from an inverse hyperbolic tangent function circuit and with the appropriate gain settings within the circuit. The efficiency of the proposed circuit depends on the accuracy of the signal obtained by the inverse hyperbolic tangent function circuit. The simulation results with Pspice® program demonstrate the efficiency of the proposed circuit for enhancing the linear operating distance of the transducer. Under a relative error a(%) of 2.2%, the linear operating range is improved from ± 9mm to ± 35mm for LVDT K <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</inf> =250(k <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</inf> =0.1) at ± 37mm full stroke length, which is much wider compared to the signal obtained from the transducer before the improvement.