An electric generator converts mechanical energy into electrical energy for use in an external circuit. This lesson introduces the generator’s purpose, its relationship to motors, and the main parts of a rotating electromagnetic generator.
In a common rotating generator, a source of mechanical power turns a shaft. The resulting motion produces electrical current at the generator’s output terminals, and that current can flow through an external circuit to power a load. The source driving the shaft is often called the prime mover.
All flashcards
What is an electric generator?
An electromechanical device that converts mechanical energy into electrical energy for use in an external circuit.
What is a prime mover?
The source of mechanical power—such as a turbine, engine, or hand crank—that turns a generator’s shaft.
How do rotor and stator differ?
The rotor is the rotating part of a machine; the stator is its stationary part.
What do the field system and armature do?
The field system produces the magnetic field. The armature is the power-producing component whose windings generate electrical current.
How are generators and motors related?
They perform opposite energy conversions: generators convert mechanical to electrical energy, while motors convert electrical to mechanical energy. Some machines can perform either role depending on how they are driven.
Quiz questions
What was a characteristic limitation of early electrostatic generators?Answer: They produced high voltage but only low current.
What does a commutator do in a dynamo?Answer: It reverses the armature winding’s external connections every half-turn, producing pulsing DC.
Why can AC systems transmit electrical power efficiently over long distances?Answer: Transformers raise transmission voltage, reducing current and resistive line losses.
When does an induction AC motor operate as a generator?Answer: When its rotor is mechanically driven faster than the rotating magnetic field’s synchronous speed.
Which description identifies Faraday’s disk?Answer: A rotating copper disk in a magnetic field that produces low-voltage direct current.
Based on the Wikipedia article Electric generator, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.