Superposition Theorem is one of the simplified circuit analysis techniques. Suppose there is an active network. Since it is an active network, there may be numbers of active sources acting simultaneously on the network. Statement … Read more
As we now know that a thyristor is a four-layered and three-junction device. The four layers being p-n-p-n, i.e. two p-type and two n-type arranged in alternate p and n layers. Practically, the layers are … Read more
There are different methods of testing of dc machines. Brake Test of DC Machine Brake test is a direct method. We apply here a brake to a water-cooled pulley mounted on the motor shaft. We … Read more
Since DC motor is a machine it must have some losses during its operation. As the current flows through armature windings and field windings, there are certain copper losses. Since the current alters its direction … Read more
There are mainly two types of dc motors. These are shunt DC motor and series DC motor. There is another type of dc motor which has features of both shunt and series motor. Since it … Read more
Before discussing the characteristics of DC motors, let us recall the expression of speed and torque of a DC motor. Because these two relationships are quite essential for understanding the characteristics of a DC motor. … Read more
Before discussing regarding torque in dc motor, let us recall the concept of torque for reference. The torque means the turning moment or twisting moment of force about an axis. We measure a torque as … Read more
Before discussing the speed control of dc motor, let us first establish the expression of the speed of a dc motor. The voltage equation of a DC motor is Where Eb is the back EMF, … Read more
Before going directly to the voltage equation of a DC motor, we may recall the significance of back EMF in the motor. Because the concept of back EMF in a DC motor is very essential … Read more