Stepper Motors and Drivers
A Step Motor is a brushless DC motor more akin to Synchronous AC motor in that while they appear as DC powered they use 2 or more pulsed DC signals. In a Stepper Motor both the Stator and the Rotor have “Teeth” but not equal in number. For more information, please read How does a Stepper Motor Work. Stepper Motor teeth form poles of a magnetic field. The rotor is constructed of multi pole magnets while the stator is constructed of 2 or more coils around shaped steel laminations. A current is applied to 1 coil; the magnetic field causes a set of stator & rotor teeth to align and the shaft moves. Another pulse to the same coil does not produce anything as the poles are already aligned. We now have 1 coil set & 1 Magnet set aligned, but other sets are now misaligned. By pulsing a second coil the rotor will move into alignment with another set of poles. So by pulsing first coil then second then back to first then the rotor will rotate or “step”. By controlling the sequence of pulses you control the direction. The distance the shaft moved is measured in degrees of rotation. A 1.8degree Stepper has 200 “teeth” and requires 200 steps to rotate 1 full rotation. An change in voltage has little effect on step motorspeed, only changing the number of pulses/sec affect speed. Where possible, we have listed the NEMA size of our step motors.
Misc. Stepper Motors and Components
Dual Shaft Stepper Motors