Dynamos produce electric current by rotating a wire within a magnetic field. Another method rotates a permanent magnet around coils of wire. Both processes produce alternating current because the wire passes between two magnetic poles every half turn. A commutator can turn the alternating current into direct current pulses, a common practice in early days before alternating current became the standard.Continue Reading
The dynamo (Greek for ?power?) includes a fixed magnetic field called a stator, an armature wrapped with the wire that rotates within the stator, and a commutator on the armature that acts like a switch between the positive and negative current generated with each rotation, sending current in only one direction with each half rotation. Smaller dynamos, like those found on bicycles, use permanent magnets, while larger dynamos need electromagnets.
Dynamos were the first type of electric generators. When engineers started understanding and using alternating current, the dynamo fell out of favor because the commutator requires mechanical contacts that rub against the armature. These contacts wear down over time, so most modern electrical generators, that need direct current output, simply convert the alternating current using diodes. Automobiles use this system to provide on-board power and charge the car?s battery.Learn more about Electricity
A bicycle dynamo works by converting the mechanical motion of the rotating wheel into electrical motion with the use of a magnet. The dynamo contains a permanent magnet wound with coils of insulated wire. When the magnet rotates, it creates a changing magnetic field, which generates electricity in the wire.Full Answer >
Isolating transformers work by having a regular step-up or step-down transformer in which two coils of insulating wire are wound around an iron containing core, but it includes a Faraday shield which isolates the coils from each other and grounds the transformer case. This effectively isolates the transformer's coil, protecting the device from grounded objects and protecting people from the dangerous, deadly high voltages.Full Answer >
An electric motor works by using magnets along with coils of wire to transfer electric energy into kinetic energy. The coil is positioned between two magnetic poles; when current passes through the coil, it experiences force in opposite directions caused by the poles of the magnet, and this causes movement.Full Answer >
The most common symbol found in electrical work and diagrams is a straight, horizontal line, which represents an electrical wire, a conductor of an electrical current. Other common symbols are horizontal and vertical lines connected by filled-in dots. These represent connected electrical wires that intersect at perpendicular angles.Full Answer >