A stepper motor is a brushless device with multiple windings, where one rotation is divided into several small steps. Stepper motors are used when precise positioning is required. Unipolar stepper motors have multiple windings connected to a common connection.
In this chapter, we’ll recycle an old floppy-disk stepper motor. Modern stepper motors are smaller and operate at lower voltages. This particular stepper motor presents a good example of the challenges that exist when driving a motor from a 12 V power supply.
Floppy-Disk Stepper Motor
Figure 27-1 shows an old 5.25-inch floppy-disk stepper motor that was sitting ...