Generators

Introduction

A generator is a device that converts mechanical energy to electrical energy for use in an external circuit. The source of mechanical energy may come from a wide array of sources, including a hand crank, an internal combustion engine, a steam turbine, a gas turbine, or a water turbine. Generators provide nearly all of the power for electric power grids. The reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors and generators have many similarities.

History

The first electromagnetic generator, the Faraday disk, was built in 1831 by British scientist Michael Faraday. Generators provide nearly all of the power for electric power grids. The reverse conversion of electrical energy into mechanical energy is done by a motor; a device that originated two years after the invention of the generator.

Principle of Operation

Generators operate on the principle of electromagnetic induction, discovered by Michael Faraday in 1831-32. Faraday found that a changing magnetic field produces an electromotive force (EMF) in a conductor—the wire—and the greater the rate of change of the magnetic field, or the greater the conductor's movement in the field, the greater the current the magnetic field produces.

Types of Generators

There are two main types of generators: AC and DC. Each of these generators can be further classified into different subtypes.

Alternating Current Generators

Alternating current generators, also known as alternators, generate an alternating current, which periodically reverses direction. They are the most commonly used type of generator, especially for large-scale power production.

Direct Current Generators

Direct current generators generate a current that flows in only one direction. These are typically used in smaller applications, such as charging batteries, powering devices in remote locations, or in certain types of vehicles.

Applications

Generators are used in a wide variety of applications, from small portable devices to large power plants. They are also used in vehicles, such as cars and boats, to provide electrical power for onboard systems.