Electrical engineering materials book pdf


In electrical engineering, an armature is the power-producing component of an electric machine. The armature’s role is twofold. The first is to carry current crossing the field, thus creating electrical engineering materials book pdf torque in a rotating machine or force in a linear machine. In the armature, an electromotive force is created by the relative motion of the armature and the field.

When the machine is used as a motor, this EMF opposes the armature current, and the armature converts electrical power to mechanical power in the form of torque, and transfers it via the shaft. When the machine is used as a generator, the armature EMF drives the armature current, and the shaft’s movement is converted to electrical power. In an induction generator, these distinctions are blurred, since the generated power is drawn from the stator, which would normally be considered the field.

A growler is used to check the armature for shorts, opens and grounds. The word armature was first used in its electrical sense, i. The parts of an alternator or related equipment can be expressed in either mechanical terms or electrical terms. Although distinctly separate these two sets of terminology are frequently used interchangeably or in combinations that include one mechanical term and one electrical term.

This may cause confusion when working with compound machines like brushless alternators, or in conversation among people who are accustomed to work with differently configured machinery. In most generators, the field magnet is rotating, and is part of the rotor, while the armature is stationary, and is part of the stator.

Both motors and generators can be built either with a stationary armature and a rotating field or a rotating armature and a stationary field. The pole piece of a permanent magnet or electromagnet and the moving, iron part of a solenoid, especially if the latter acts as a switch or relay, may also be referred to as armatures. Rotor: The rotating part of an alternator, generator, dynamo or motor. Armature: The power-producing component of an alternator, generator, dynamo or motor.

The armature can be on either the rotor or the stator. Field: The magnetic field component of an alternator, generator, dynamo or motor. The field can be on either the rotor or the stator and can be either an electromagnet or a permanent magnet.

In a DC machine, the main field is produced by field coils. In both the generating and motoring modes, the armature carries current and a magnetic field is established, which is called the armature flux.