Generator
An electric generator is a device that converts mechanical energy to electrical energy. It is simply a device that moves a magnet near a wire to create a steady flow of electrons. The action that forces this movement varies greatly, ranging from hand cranks and steam engines to nuclear fission, but the principle remains the same.
The two main parts of a generator or motor can be described in either mechanical or electrical terms:
Mechanical:
- Rotor: The rotating part of an electrical machine
- Stator: The stationary part of an electrical machine
Electrical:
- Armature: The power-producing component of an electrical machine. In a generator, alternator, or dynamo the armature windings generate the electric current. The armature can be on either the rotor or the stator.
- Field: The magnetic field component of an electrical machine. The magnetic field of the dynamo or alternator can be provided by either electromagnets or permanent magnets mounted on either the rotor or the stator.
[edit] Human powered electrical generators
Self-powered equipment is a term used for electrical appliances which can be powered by human muscle power as an alternative to conventional sources of electricity such as primary batteries and the power grid. Such devices contain electrical generators or an induction system to recharge their batteries. Separate crank-operated generators are now available to recharge battery-powered portable electronic devices such as cell phones. Others, such as mechanically powered flashlights, have the generator integrated within the device itself. A promising alternative to rechargeable batteries for electricity storage is supercapacitors, now being used in some devices such as the mechanically powered flashlight shown here.
[edit] Benefit
Self-powered devices are useful as emergency equipment, when natural disaster, war, or civil disturbance make regular power supplies unavailable. It has been seen as economical for use in poor countries, where batteries may be expensive. They are also an environmentally preferable alternative to the use of disposable batteries, which are wasteful source of energy and may introduce heavy metals into the environment.
