DC motors

Almost every mechanical movement that we see around us is accomplished by an Electric Motor. Electric
machines are a means of converting energy. Motors take electrical energy and produce mechanical energy.
Electric motors are used to power hundreds of devices we use in everyday life. Motors come in various sizes.
Huge motors that can take loads of 1000’s of Horsepower are typically used in the industry. Some examples of
large motor applications include elevators, electric trains, hoists, and heavy metal rolling mills. Examples of
small motor applications include motors used in automobiles, robots, hand power tools and food blenders.
Micro-machines are electric machines with parts the size of red blood cells, and find many applications in

medicine.

Electric motors are broadly classified into two different categories: DC (Direct Current) and AC (Alternating
Current). Within these categories are numerous types, each offering unique abilities that suit them well for
specific applications. In most cases, regardless of type, electric motors consist of a stator (stationary field) and a
rotor (the rotating field or armature) and operate through the interaction of magnetic flux and electric current to
produce rotational speed and torque. DC motors are distinguished by their ability to operate from direct current.
There are different kinds of D.C. motors, but they all work on the same principles. In this chapter, we will study
their basic principle of operation and their characteristics. It’s important to understand motor characteristics so
we can choose the right one for our application requirement.