Design and dynamic calculations for miniature permanent magnet stepper motors

The paper deals with the performance characteristics of rotary and linear permanent magnet actuators, whose design emphasis lies in the simplicity of the device and its drive. The field of application of such systems includes electromechanical timers and vibrators. In their design and optimisation, requirements have to be met regarding the torque (or force) developed, the duty cycle, and physical size. The design and analysis approach presented combines the finite element technique to solve the partial differential equation governing the magnetic field, and a dynamic systems simulation to solve the differential equations governing the electro-mechanical system. The effect on performance of the type of drive is considered and design information to obtain the correct balance of excitation and saliency effects is included.