Page 729 - Basic Electrical Engineering

9

Single-phase Motors

TOPICS DISCUSSED

Revolving field theory
Single-phase split-phase induction motors
Torque-speed characteristic and applications
Shaded pole induction motor
AC series motor
Universal motor
Single-phase synchronous motors
Stepper motors

9.1 INTRODUCTION TO SINGLE-PHASE INDUCTION MOTORS

Single-phase induction motors are widely used in electrical appliances and

gadgets like ceiling fans, exhaust fans, refrigerators, washing machines, etc.
They require only single-phase supply to the stator. The rotor is squirrel-cage

type and does not require any supply from a separate source.

9.2 CONSTRUCTIONAL DETAILS

The constructional details of single-phase induction motors are more or less

the same as that of three-phase induction motors except that the stator will
have a single-phase winding and the rotor is of squirrel-cage type. Slip-ring-
type rotor construction is not done for single-phase motors. Single-phase

induction motors as such do not develop starting torque unless some