A Low-cost Small-sized Eddy Current Displacement Sensor

This paper designs small-sized printed circuit board (PCB) coils along with commercial inductance-to-digital converter (LDC) from Texas Instruments, and evaluates its potential for space limited bearingless motor applications, e.g., artificial hearts. For instance, the rarial displacement of the rotor, measured in x- and y-components, can be captured by two PCB coils with one LDC1612 chip. The measurement range and resolution of the sensor are measured in experiments, and variants of PCB coil shapes are further considered and compared.