Detecting position of movable coil inside linear electromagnetic actuator, by measuring circuit phase angle

摘要

The circuit phase angle can be measured to give an indication of the position of the coil (3) in relation to the core material (1), enabling the mean current in the coil to be regulated in order to control actuator force, and enabling an alternating current component to be generated. The actuator contains a gap (6) magnetized by one or more permanent magnets (2). A coil inside the gap can move between two end positions, and the amount of core material surrounded by the coil varies with length. The coil is connected to a controllable power supply (7).