Theory and Applications of Step Motors

acceleration air gap applications back emf bipolar closed-loop closed-loop control Coil constant control systems damping deceleration degrees diagram displacement dynamic eddy currents EHSM electric step motor energized equations excitation feedback final speed flux linkages frequency function holding torque hydraulic motor incremental inertia input lead angle linear linear motor logic loop low speed magnetic circuit magnetomotive force maximum mechanical motion msec msec/div multiple-stack mutual inductances number of steps one-phase-on open-loop open-loop control operation oscillator output permanent magnet permeance phase currents platen ramp rotation rotor position rotor teeth scheme sensor sequence servo-valve shaft shown in Figure shows simulation single-stack Single-step response slew rate static torque curves stator teeth stator windings step angle step motor system step response steps per second subroutine switching angle synchronous three-phase torque curves Torque oz-in unipolar velocity VR motor VR step motor zero