A DC motor can be described as a simple electric motor that requires a battery or DC supply to run it. Technically speaking, it has two magnets that have opposite polarity and an electrical coil that works like an electromagnet. The electromagnetic force of the magnet generates a torque that turns the motor. Any motor will have the six basic parts of shaft, rotor, stator, commutator, field magnet, and brushes. Most DC motors use high resistance magnets to obtain a strong external magnetic field.
It is used for a variety of products such as electric razor, power car window, and remote control cars. By allowing the speed and torque ratio to be varied, these DC motors found wide industrial application. This property helps us convert engines into many useful forms. Even the speed characteristic of the motor can be smoothly controlled to zero followed by acceleration in the opposite direction without any change in the power circuit. All DC motors respond quickly to any changes in control signals due to their high torque to inertia ratio.
These motors can also be placed in locations where they are required to momentarily deliver more times their rated torque. Even in an emergency situation, it can deliver five times its rated torque without stopping when getting the required power supply. This dynamic braking or regenerative braking function of DC motors is used for applications that require quick stops. Different types of motors include DC, permanent magnet, and brushless motors. Field-wound types can be further classified as shunt-wound, series-wound, and compound-wound DC motors. Motors can also be rated for intermittent or continuous duty.
Selecting the motor for a given application requires consideration of factors such as its speed range, speed variation with torque, reversal, duty cycle, peak torque, and heating. For example, if field control is to be used, a higher speed range is required on the motor. Having a simple design, reliability and offering different features, it can be chosen for different uses. It has also been a fascinating way for many students to study the different effects of the magnetic field.