As in the case of plain oil circuit breaker described earlier, the quantity of oil required reaches very high figures with the increase in system voltage. This vast quantity of oil increases the size of the breaker and maintenance problems. We know that the oil in the circuit breaker performs two functions. Firstly, it acts […]
In an oil circuit breaker or OCB, the separating contacts of the breaker are made to separate within an insulating oil because insulating oil has better insulating properties than air. Oil Circuit Breaker Working Principle When a fault occurs, the breaker contacts open in oil, an arc is struck between them. Due to the heat
The performance of a DC motor can be judged by its characteristics and a motor for any particular application can be selected easily. The performance characteristics of DC motor are: Torque versus armature current (T v/s Ia) Speed versus armature current (N v/s Ia) Torque versus speed (T v/s N) Characteristics of DC Motor While
The speed control of dc series motor can be obtained by using various methods shown in the figure. Following few facts about the DC series motor should be kept in mind while studying DC series motor speed control. The current flowing through the armature and field winding of a DC series motor is same. The
Before discussing the speed control of dc shunt motor, we have to find the factors affecting the speed of a DC motor. The speed equation of a DC motor shows that, N α Eb / φ or N α (V – IaRa)/ φ But the resistance of armature winding is small. Therefore the voltage drops IaRa will be
Types of DC Motor Following are the different types of dc motor: Series DC Motor Shunt DC Motor Compound DC Motor Separately excited DC motors Permanent Magnet DC Motor Series DC Motor The connection for a series-type DC motor is illustrated in Figure 1. A series-wound DC motor consists of a series field winding (identified
The working principle of DC motor can be stated as follows: When a current-carrying conductor is placed in a magnetic field, it experiences a force. In the case of a DC motor, the magnetic field is produced by the field winding. And the armature winding is connected to the external supply voltage hence it plays
Hi friends, In this article, I am discussing the construction of dc motor and hoping you will find it useful. Both the DC machines i.e. DC generator and DC motor have the same construction. Therefore, either machine can be used as a motor or a generator. So the following discussion about the construction of DC
Auto Transformer Working Principle The auto transformer working principle and construction is similar to that of conventional two winding transformers. However, it differs in the way in which the primary and the secondary are inter-related. In a two-winding transformer, primary and secondary are only magnetically linked by a common core but are completely insulated from
There are many types of transformers. These can be classified on a different basis. The following are the main types of transformers. Types of Transformers based on Voltage Level 1. Step-Down Transformer: The transformers having K > 1 i.e. N2 > N1 are known as the step-up transformer. Here, we get high output voltage as compared