Understanding DC Machine Armature Winding-1 — Lesson 6

This lesson covers the detailed explanation of Direct Current (DC) machines, focusing on the structure and function of the stator and rotor. It discusses the concept of field coils and armature windings, and how they contribute to the operation of a DC machine. The lesson also delves into the specifics of coil sides, induced EMF, and the importance of maximizing the induced EMF. It further explains the concept of double layer winding and the process of placing coils in the rotor slots. The lesson concludes with the discussion on the connection of coils in series and the generation of DC from the AC voltage induced in the coils.

Video Highlights

01:30 - Discussion on the nature of the induced voltage in a DC machine
05:40 - Discussion on the structure of the rotor windings in a DC machine
10:10 - Explanation of the concept of double layer winding in a DC machine
30:04 -Discussion on the induced voltages in the coils of a DC machine
38:26 - Conclusion and preview of the next class

Key Takeaways

• A DC machine consists of a stator and a rotor, with field coils around the stator and armature windings on the rotor.
• Each coil in the rotor has two coil sides, and the induced EMF is maximized when one coil side is under the North Pole and the other under the South Pole.
• In a double layer winding, each slot houses two coil sides, generally belonging to different coils.
• All the coils are connected in series and the circuit is closed, ensuring no circulating current despite each coil being a seat of EMF.
• The conversion of AC voltage induced in the coils to DC is achieved through a specific arrangement and connection of the coils.