NULL-SEEKING POSITION SENSOR

摘要

A position sensor comprised of two primary sense windings for establishing a forward or drive field, two secondary sense windings in which a voltage may be induced in the presence of the drive field, and at least one conductive screen capable of blocking the magnetic coupling between the primary and secondary sense windings. When the screen blocks the magnetic coupling between one pair of sense windings to the same extent that it does between the other pair of sense windings, the sensor circuitry generates a marker signal to indicate the position of the screen.