Patent ID: 7893687
Filing Date: 2011-02-22
Classification: G01D

Abstract:
1. A device for decoding signals at the output of a linear variable differential transformer (LVDT), the LVDT comprising: a primary coil; a first secondary coil arranged coaxially at a first end of the primary coil; a second secondary coil arranged coaxially at a second end of the primary coil; and a slidable ferromagnetic part excited by the primary coil, the device comprising: an analog to digital converter connected to both an output of the first secondary coil and to an output of the second secondary coil, producing first and second digitized outputs; a multiplier module, multiplying the first and second digitized outputs respectively by first and second predetermined factors respectively, producing first and second multiplied outputs; an error calculation module for calculating a position error of the ferromagnetic part, using the first and second multiplied outputs, the error calculation module comprising: a first synchronous demodulation channel applied to the first multiplied output; and a second synchronous demodulation channel applied to the second multiplied output.