Motor control is required in many applications – not only for fans and ventilation systems. Conveyors, pumps, and 3D printers are also equipped with motors that cannot be simply operated in on-off mode. Motor power and rotation direction also need to be controlled. To make make this an easy introduction, here we only consider conventional DC motors, stepper motors, and low-power brushless motors.  

The circuits shown in this article are intended to illustrate the individual sections and serve as starting points for your own designs, not as finished designs that you can copy directly. First, let’s look at a simple DC motor. In this case, it is a motor with a rated operating voltage of 3 V to 6 V and a maximum operating current of 1 A. Motors of this sort are included in many starter kits, such as the Basic Kit for Raspberry Pi Pico (Figure 1).

The Basic Kit for Raspberry Pi Pico
Figure 1: The Basic Kit for Raspberry Pi Pico
with a DC motor. (Source: Kuongshun)

In the latter case, the supply voltage is...