DC Motors

IDIS - 300

Energy Transformation

Magnetic Field

CurrentMechanical Force(Rotation)

Interaction of Fields

Right Hand Rule

Value of Mechanical Force

Assuming that the conductor is located at right angles to the magnetic field, the force developed can be expressed as follows:

F = B I L

F = Force (Newtons)B = Magnetic Flux Density (Tesla)I = Current (Amps)L = Length in meters

Force Generated by Fields

Motor Operation

Basic Construction

Types of DC Motors

Types of DC Motors

Depending upon the connection of armature winding and field windings DC Motors are classified as:

Series DC MotorShunt DC MotorCompound DC Motor

Series DC Motor

Series Motor Limitations

No Load = Infinite Speed !

Shunt DC Motor

Counter EMF

CEMF proportional to rpm ???

Calculate CEMF

Horsepower Folklore

Horsepower and Torque

Horsepower delivered by Motor

Torque generated by Motor

Exercise:

Speed of DC Motor

Calculating the speed of CD-ROM

Counter EMF and Speed