Sensors, Vol. 22, Pages 3674: Linear-Range Extension for Linear Variable Differential Transformer Using Hyperbolic Sine Function

Sensors, Vol. 22, Pages 3674: Linear-Range Extension for Linear Variable Differential Transformer Using Hyperbolic Sine Function Sensors doi: 10.3390/s22103674 Authors: Apinai Rerkratn Jakkapun Tongcharoen Wandee Petchmaneelumka Vanchai Riewruja In this paper, a circuit technique to extend the measuring range of a linear variable differential transformer (LVDT) is proposed. The transfer characteristic of the LVDT contains the odd function form of the cubic polynomial. Therefore, the measuring range of a commercial LVDT is linear in a narrow range compared to its physical dimensions. The wide measuring range of the LVDT requires a large structure of the LVDT, which increases the scale and the cost of the measurement system. The measuring range of the LVDT can be linearly extended to the maximum of the stroke range using the proposed technique. The realization of the proposed technique is based on the use of the hyperbolic sine (sinh) function of the electronic circuit building block, named the class AB bipolar amplifier. The class AB bipolar amplifier can be obtained by the current feedback operational amplifier (CFOA). The circuit of the proposed technique requires two CFOAs and an operational transconductance amplifier (OTA) as the active devices and all devices used in the proposed technique to synthesize the sinh function are commercially available. The proposed technique exhibits an ability to compensate for the nonlinear characteristic of the LVDT without d...
Source: Sensors - Category: Biotechnology Authors: Tags: Article Source Type: research