SPICE modeling of a stepper motor with its control, drive and load

SPICE modeling of a complete stepper motor system is described. Using a voltage-controlled oscillator to track sine and cosine of rotor angle and using an electrical analog of the mechanical assembly, SPICE simulates interactions between electrical and mechanical subsystems. The simulations confirm the effectiveness of preloading against gear backlash and dead-beating against excitation of mechanical resonances. A method for extracting frequency-domain information from this inherently time-domain model is also discussed.<>