US Patent 7893687 LVDT acquisition device with dual demodulation subsystem

The invention relates to position sensors of the linearly variable induction difference type. When cost constraints prevent the use of transformers with guaranteed phase-shift tolerance to achieve an accuracy objective, it is advantageous to provide an independent demodulation of the signals of the two windings. The error signal thus has a lower dependence on the phase shift and the accuracy is typically enhanced by a factor greater than an order of magnitude.