Patent ID: 7391202

Claim:
A linear variable differential transformer (LVDT) system comprising: an LVDT; and a signal conditioner circuit coupled to the LVDT, the signal conditioner circuit using an inductance of a primary of the LVDT as a micro-power excitation carrier frequency to lower a drive power of the system, wherein the signal conditioner circuit comprises: an oscillator coupled to an input of the LVDT, an output frequency of the oscillator tuned to a desired frequency by setting the value of an inductance supplied across secondary coils of the LVDT; a demodulator coupled to an output of the LVDT and to the oscillator, the demodulator having two orthogonal magnetic devices for multiplying a modulated carrier output of the LVDT by the output frequency of the oscillator; and a low pass filter coupled to an output of the demodulator, the low pass filter removes second harmonic frequency components generated by multiplication of the output frequency of the oscillator and the output of the LVDT.