DC Motor
DC Motor is a type of electrical motors which uses direct current as a source of electrical power and converts the power into mechanical energy.
Working principle of DC Motor
The DC motor works on the principle of the magnetic field. When the Electric field and magnetic field interact, the torque produces.
Or simply when a current-carrying conductor is placed in a magnetic field it produces a mechanical force on the conductor. The working principle of DC motor are also the same.
The next step is to find the direction of rotation. We use Fleming’s Left-hand rule to find the direction. The speed of the DC motor depends upon the emf. The formula for generated emf is.
Where
- P is the Numbers of poles
- φ is flux per pole
- Z is the Numbers of conductors
- N is the speed of the DC motor
- A is the Numbers of parallel paths
Types of DC Motors
Nowadays DC motors are commonly used. It has different applications. Based on different applications DC motors are divided into four main types. i.e. permanent magnet, series, shunt, and compound DC motors.
We will discuss each type of motor in detail.
Permanent Magnet DC Motors
In this type of DC motor, a permanent magnet is used for creating flux. The main usage of this type of motors is low horsepower applications, like windshield wipers, Blowers, and washers.
Besides this, in other applications where speed control is not necessary, this type of motors is the best choice. These types of motors provide enough speed regulation and starting torque.
Series DC Motors
This type of motor is also called series wound motors. In this type of motors, the field winding is connected in series with the armature winding.
Series DC motor produces a large amount of starting torque. One of it limitation is that it cannot regulate speed. These are not fit for variable speed and If it is run with no load the coil can be damaged.
Shunt DC Motors
In this type, the field winding is connected in parallel (shunt) with the armature windings. If you need better speed regulations, this type of motor is the best choice. Shunt Motors offer better speed regulation.
Centrifugal Pumps, Weaving Machines, Lifts, Conveyor built, Lathe Machines, Fans have these types of motors.
- Compound DC motor
Compound type is the combination of both series and Shunt DC motors.In this type of motors, the armature windings & field windings are connected in both shunt and series combinations.
Due to their combined characteristics, these types of motors offer good starting torque. Also, it is used in variable speed applications.
