Principle of Electric Motor - Essay Example

In practical applications an electric motor has a large number of loops attached to the coil armature and the magnetic field is generally produced by large electromagnets. Mainly two types of electric motors are widely used and there is a slight difference between the working principles of DC and AC electric motors. Working of DC and AC electric Motor: In DC electric motor electricity to the armature coil is supplied through a commutator.

The commutator reverses the current after every half cycle so that the torque applied to the armature is in one direction only and thus the coil rotates in a single direction. In an AC electric motor, the AC current is passed through the rotating contacts. These rotating contacts are also called brushes and the main disadvantage of these AC motors is that a part of the energy is wasted as heat, which also shortens the life of the electric motor, however in an AC motor the magnetic field is also produced by the same AC voltage (Hyper Physics, n.d.).

The coil for producing electromagnetic field is also known as stator and the other coil attached to the core is known as an armature. The diagram of the DC and Ac motor is given in Figure-1.Discussion: So these two types of common electrical motors as we have seen above are the best example of utilizing electromagnetic principles for our use. As it is the fundamental principle that energy can neither be created nor be destroyed but it can be converted from one form to another. The conversion of one form of energy to another form should be carried out in an efficient way but as we have seen lots of energy is wasted as heat.

Further electrical wiring is made around a soft iron core and due to heat the iron core also damages quickly hence the life of the motor is also limited. These are some of the disadvantages of these electric motors, however, a number of new modifications such as coreless DC motors, AC induction motors, brushless DC motors have already been in use for minimizing some of the problems associated with the conventional motors. Conclusion: Electric motors are necessary equipment used in our day-to-day life.

These are essential items in some of our home appliances such as fan, pool pumps, fridges, washing machines, fan-forced ovens, etc and we will remain dependant on various electrical motors.