pp. 475-485
S&M2115 Research Paper of Special Issue https://doi.org/10.18494/SAM.2020.2407 Published: February 10, 2020 Linear-range Extension for Linear Variable Differential Transformer Using Binomial Series [PDF] Wandee Petchmaneelumka, Kanoknuch Songsuwankit, Jakkapun Tongcharoen, and Vanchai Riewruja (Received April 11, 2019; Accepted December 23, 2019) Keywords: linear variable differential transformer, inductive transducer, linear range extension, binomial series, operational amplifier, analog multiplier
The linear-range extension technique for a linear variable differential transformer (LVDT) is described in this paper. Generally, the LVDT has a narrow linear operating range caused by its nonlinear transfer characteristic. To extend the linear operating range, the nonlinear behavior of the LVDT must be adjusted. In this paper, the circuit building block providing the LVDT inverse transfer characteristic using binomial series approximation is proposed for linearizing the nonlinear behavior of the LVDT. The third-order inverse transfer characteristic of the LVDT is synthesized from analog multipliers and a difference amplifier comprising an operational amplifier (opamp). All active devices used in this study are commercially available. Therefore, the attraction of the proposed technique is in the simple configuration and low cost, making it suitable for an embedded measurement system. The performance of the proposed technique is discussed in detail. Simulation and experimental results confirming the performance are also included. As a result, the linear range of the commercial LVDT used in this study can be extended more than 500%. The full scale error of the measured value is about 0.23% over the entire operating range.
Corresponding author: Kanoknuch SongsuwankitThis work is licensed under a Creative Commons Attribution 4.0 International License. Cite this article Wandee Petchmaneelumka, Kanoknuch Songsuwankit, Jakkapun Tongcharoen, and Vanchai Riewruja, Linear-range Extension for Linear Variable Differential Transformer Using Binomial Series, Sens. Mater., Vol. 32, No. 2, 2020, p. 475-485. |