What describes a Compound DC Motor?

What describes a Compound DC Motor?

• A. Only series winding
• B. High speed regulation but low torque
• C. Mix of series and shunt - balance of torque and speed regulation
• D. Low efficiency

Answer: (C)

A compound DC motor uses two field windings: a series winding in series with the armature and a shunt winding in parallel with the armature. This setup blends the advantages of both motor types. The series path provides high starting torque because the current through the armature also drives a strong series field. The shunt path, with a separate, relatively constant field, helps keep speed from changing too much as load varies. When the fields reinforce each other (the common arrangement called cumulative), the motor starts with strong torque and then maintains a more stable speed under load. In short, it’s a mix of series and shunt behavior that balances torque and speed regulation, unlike a pure series motor (high torque, poor speed regulation) or a pure shunt motor (stable speed, lower starting torque).

A compound DC motor uses two field windings: a series winding in series with the armature and a shunt winding in parallel with the armature. This setup blends the advantages of both motor types. The series path provides high starting torque because the current through the armature also drives a strong series field. The shunt path, with a separate, relatively constant field, helps keep speed from changing too much as load varies. When the fields reinforce each other (the common arrangement called cumulative), the motor starts with strong torque and then maintains a more stable speed under load. In short, it’s a mix of series and shunt behavior that balances torque and speed regulation, unlike a pure series motor (high torque, poor speed regulation) or a pure shunt motor (stable speed, lower starting torque).