Question

With the help of a diagram, explain the working of a universal motor.

Hint:

Universal motors run on both AC and DC and are ideal for high-speed applications.

Answer 1

Basic Construction: A universal motor is similar to a series DC motor with a stator and rotor winding connected in series. It can operate on both AC and DC supply.

When connected to AC supply, the current flows through both stator and rotor windings.
Both the field and armature currents reverse simultaneously, so the direction of torque remains the same.
The interaction between the magnetic field created by the stator and the current in the rotor winding produces torque, causing the motor to rotate.
It runs at very high speed and is commonly used in portable power tools and domestic appliances.