This lesson covers the fundamental concepts of DC motor operations, focusing on the starting, speed control, and braking of the motor. It explains the importance of the back EMF equation and the torque equation in understanding the operation of a DC motor. The lesson also discusses the role of armature resistance in controlling the starting current and the use of external resistance to limit this current. It introduces the concept of a 3-point starter, an electromechanical device used to start a DC shunt motor, and explains its operation and protective features. The lesson concludes with a brief introduction to the speed control of DC motors.
02:36 -Explanation of the starting of a DC motor
07:58 - Explanation of the process of connecting an external resistance in the armature circuit
14:25 - Explanation of the 3 point starter circuit
30:44 - Discussion on the role of the NVRC (No Volt Release Coil) and OLRC (Overload Release Coil) in the 3 point starter
37:38 -Conclusion of the lecture and introduction to the next topic