An improved magnetic position sensor

Significant improvement in the overall performance of a position sensor based on the effective permeability of a slender ferromagnetic core element is obtained by modifying the construction. The need for a bias field is eliminated by tilting the polarizing magnet(s) in the magnetic-core plane. The resulting longitudinally asymmetric magnetizing fields divide the core element into oppositely polarized regions having unequal intensities of remanent magnetization with distinctive incremental permeabilities. The magnet position determines the relative length of each region and therefore the effective permeability of the core element as a whole. When the effective permeability is determined from the inductance of a solenoid wound over the core element, nonlinearities due to various end effects and the magnet's proximity can be corrected by local variation of the winding pitch. Application-specific nonlinear transfer functions are also obtained in this manner.<>