Introduction Before reading this Tutorial, the reader should first review the Unipolar and Bipolar Stepper Tutorials. With a grasp of basic Stepper control, you are now ready to tackle the more sophisticated aspect of stepper theory: Current Control. There are several reasons for implementing current control… – Avoid Overheating– Accommodate a variety of Motors– Increase […]
Unipolar Stepper Motor and Control
Introduction Stepper Motors have several features which distinguish them from AC Motors, and DC Servo Motors. Brushless – Steppers are brushless. Motors with contact brushes create sparks, undesirable in certain environments. (Space missions, for example.) Holding Torque – Steppers have very good low speed and holding torque. Steppers are usually rated in terms of their holding force […]
Microstepping of Stepper Motors
The ideal current waveform for driving a stepper motor is a Sinewave. Two sinewaves in ‘quadrature’ (90 degrees out of phase) form the ideal current drive. If the two stepper coils follow the current waveforms depicted in diagram 1, the motor will run quietly and smoothly, the ideal condition. In fact, the “step” usually associated with stepper […]
Bipolar Stepper Motor and Control
Introduction The Bipolar Stepper motor is very similar to the Unipolar Stepper discussed in part I of this Tutorial, except that the motor coils lack center taps. Because of this, the Bipolar motor requires a different type of controller, one that reverses the current flow through the coils by alternating polarity of the terminals, giving […]