Electrical

To overcome the quantization errors due to slope overload and granular noise, the step size (δ) is made adaptive to variations in the input signal x(t). Particularly in the steep segment of the signal x(t), the step size is increased. When the input is varying slowly, the step size is reduced. Then the method is

The automatic frequency correction (AFC) is incorporated in FM transmitter to keep carrier frequency stable. The discriminator reacts only to small changes in the carrier frequency but not to the frequency deviations in the carrier (since it is too fast). Suppose frequency of the carrier increases. This higher frequency is fed to the mixer for

Angle modulation has following advantages over amplitude modulation (AM): The amplitude of FM is constant. It is independent of depth of modulation. Hence transmitter power remains constant in FM whereas in FM it varies in AM. Since amplitude of FM is constant, the noise interference is minimum in FM. Any noise superimposing an amplitude can

3Φ AC synchronous motor Revolving armature type Revolving field type Conventional 3Φ Synchronous Motor : (Revolving Field Type) Stator : Stator is made up of silicon steel stampings. Stator slots carry a balanced 3Φ armature winding, wound for a specified even number of poles. The ends of the armature windings are connected to the terminals

Merits of SRM Construction is simple and robust. Rotor carries no windings, no sliprings, no brushes, less maintenance. There is no permanent magnets. Ventilating system is simpler as losses takes place mostly in the stator: Power semi conductor switching circuitry is simpler No shoot through fault likely to happen power short circuits. Developed torque doesn’t

SRM is a single excited and double salient pole electric motor. It is an electromagnetic and electrodynamic equipment. Switched reluctance motor operating principle is similar to a single-stack variable-reluctance stepping motor. However, design procedures and control strategies in VRM are different from those used in a stepping motor. For example, a SRM requires a rotor

Figure shows evolution of brushless dc motor. Conventional DC Motor The first stage of evolution of DC motor is conventional type DC motor. It is an electro magnetic and electro dynamic equipment. Sator Stator is made up of forced steel with inward projected poles. The poles carrying field windings. The field windings are connected such

It is a signal phase motor whose operation depends upon the hysteresis (magnetisation produced in a ferromagnetic material lags behind the magnetising force) and on the presence of continuously revolving magnetic flux. Construction A stator designed to produce a synchronously revolving field from a single phase supply. This is accomplished by using permanent split capacitor

A universal motor is a specially designed series wound motor, that operates at approximately the same speed and output on either dc or ac of approximately same voltage. Construction A universal motor is similar to a de series motor in construction. It is constructed with few series field turns, laminated armature and field circuits, low