Method and apparatus for detection of LVDT core fallout condition

An apparatus comprises:

• a circuit configured to measure a first voltage (VA) across a first sensing coil of a linear variable differential transformer (LVDT) and measure a second voltage (VB) across a second sensing coil of the LVDT;
• and
• a processing device configured to signal a core fallout condition in response to:
• (i) determining that a ratio of VA and VB is within a specified range of a value of one;
• and
• (ii) determining that a sum of VA and VB is less than a sum of VA0 and VB0 by more than a specified amount, where VA0 and VB0 are minimum voltages across the first and second sensing coils of the LVDT, respectively, when a core of the LVDT is in the LVDT.

A non-transitory computer readable medium embodying a computer program, the computer program comprising computer readable program code for:

• receiving a measurement of a first voltage (VA) across a first sensing coil of a linear variable differential transformer (LVDT) and a measurement of a second voltage (VB) across a second sensing coil of the LVDT;
• and
• signaling a core fallout condition in response to:
• (i) determining that a ratio of VA and VB is within a specified range of a value of one;
• and
• (ii) determining that a sum of VA and VB is less than a sum of VA0 and VB0 by more than a specified amount, where VA0 and VB0 are minimum voltages across the first and second sensing coils of the LVDT, respectively, when a core of the LVDT is in the LVDT.