Magnetic flux detection device has a sensor coil wound around the core of an electric motor drive to provide a measure of the flux to be used in controlling the motor

摘要

Device comprises a sensor coil (14) wound around a core (13) forming a magnetic circuit for driving a linear motor (1). The core is excited by discharging a high frequency current to the coil, so that the coil is not saturated and Eddy currents are generated in the core. The impedance of the transmitter coil is determined in this state and the size of the magnetic flux in the core is determined based on the coil impedance.