Stepper motor: A brief overview
Stepper motors are ubiquitous. They are used in a wide range of applications from robots, printers, industrial position control, projectors, cameras and so many more. A stepper motor typically has two electrical windings. An H-bridge is used to drive each winding. Motor position is controlled by regulating the current in motor windings. For a smooth motor motion profile and finer position control, micro-stepping is desired. While micro-stepping, the current in these windings is regulated in a sine (red) and cosine (blue) function (see Figure 1). Each step corresponds to a preset current level. Having a non-optimal decay scheme does not allow for good micro-stepping, which translates to poor motor position control.