It is interesting to know how a single-phase induction motor can able to rotate when an initial rotation or starting torque is given to it. This can understand with the help of cross-field theory and double-revolving field theory…
When a single-phase ac supply is given to the single-phase stator winding, a sinusoidally pulsating magnetic field varying with time is produced. As the produced magnetic very two times in a cycle, therefore, no torque will be pr…
Industrial as well as domestic loads need speed variation. Some of the loads require to change the speed in steps and some of the motors require to change the speed uniformly. For instance, in the paper industry, while rolling th…
Torque or moment or moment of force is the tendency of a force to rotate or move an object about an axis. A force is a push or pull, likewise, torque is a twist to an object. Mathematically, torque, T = F × r. Let T g = armatu…
What is Back EMF in DC Motor : When the armature of a dc motor rotates, the windings or conductors on the armature also rotate in the magnetic field. According to "Faraday's Laws of Electro-Magnetic Induction" emf …
The power flow from input to output is known as power stages or power flow diagram. Efficiency : It may be defined as the ratio of output in watt (or KW) to the input in watt (or KW). Mechanical efficiency, Electrical eff…
Conditions for Parallel Operation of Dc Generator : To connects the generators in parallel to common bus-bars, the generators should satisfy the following conditions. The incoming generator's voltage should be the same as t…
Lap Winding : When the winding is connected in such a manner that the end of the one coil is connected to the starting end of other coils (adjacent coil) of the same pole and so on then the winding is known as lap winding. Lap…
There are two methods of improving commutation i.e., for making current reversal in the short-circuited coil as sparkless as possible. They are, Resistance commutation. EMF commutation (it is done with the help of brush-lead or i…
Based on the methods of the interconnection of windings the following types of dc generators are available. Separately-excited DC Generator Self-excited DC Generators Shunt-field connection, Series-field connection, and Compound-…
We know that the working principle of dc generator, that when conductors begin to cut the magnetic lines of force and therefore, the e.m.f. induces in the conductors according to 'Faraday's Law of Electromagnetic Inducti…
Working Principle of DC Generator : A simple coil of wire ABCD is mounted on a shaft between two magnetic poles. The two ends of the coil are connected to two slip rings, S 1 , S 2 which are mounted on the same shaft. The slip …
