About Motors and its types...

An electric motor is a motor that uses electrical energy to produce mechanical

energy, usually through the interaction of magnetic fields and current-carrying conductors.

The reverse process, producing electrical energy from mechanical energy is accomplished by

a generator or dynamo. Traction motors used on vehicles often perform both tasks.

Electric motors can be run as generators and vice versa, although this is not always

arctic Electric motors are ubiquitous, being found in applications as diverse as industrial

fons blowers and pumps, machine tools, household appliances, power tools, and disk drives

They may be powered by direct current (for example a battery powered portable device or

motor vehicle) or by alternating current from a central electrical distribution grid.

The smallest motors may be found in an electric wristwatch. Medium-size motors of

Highly standardized dimensions and characteristics provide convenient mechanical power for

industrial uses. The very largest electric motors are used for the propulsion of large ships, and for

such purposes as pipeline compressors, with ratings in the millions of watts. Electric motors

may be classified by the source of electric power, by their internal construction, and by their

replication

The physical principle of production of mechanical force by the interactions of an

electric current and a magnetic field was known as early as 1821. Electric motors of

Increasing efficiency was constructed throughout the 19th century, but commercial

lation of electric motors on a large scale required efficient electrical generators and

Electrical distribution networks.

y convention electric engine refers to a railroad electric locomotive, rather than an

electric motor

DC MOTORS

A DC motor is designed to run on DC electric power, Two examples of pure DC

Creator, which is (so far) a novelty.

Designs are Michael Faraday’s homopolar motor (which is uncommon), and the ball bearing

By far the most common DC motor types are the brushed and brushless types, which

Se internal and external commutation respectively to create an oscillating AC current from

He DE source-so they are not purely DC machines in a strict sense.

AC MOTORS

In 1882, Nikola Tesla discovered the rotating magnetic field, and pioneered the use of

Ary field of force to operate machines. He exploited the principle to design a unique two

Se induction motor in 1883. In 1885. Galileo Ferraris independently researched the

Concept, In 1888. Ferraris published his research in a paper to the Royal Academy of

Sciences in Turin

Tesla had suggested that the commutators from a machine could be removed and the

The device could operate on a rotary field of force. Professor Poeschel, his teacher, stated that

Would be akin to building a perpetual motion machine,

Tesla would later attain U.S. Patent 0416194 Electric Motor (December 1889),

Which resembles the motor seen in many of Tesla’s photos. This classic alternating current

The electro-magnetic motor was an induction motor.

Mikhail Osipovich Dolivo-Dobrovolsky later invented a three-phase “cage-rotor” in

His type of motor is now used for the vast majority of commercial applications

STEPPER MOTORS

Closely related in design to three-phase AC synchronous motors are stepper motors,

bere an internal rotor containing permanent magnets or a magnetically-soft rotor with

agent poles are controlled by a set of external magnets that are switched electronically. A

a stepper motor may also be thought of like a cross between a DC the electric motor and a rotary

As each coil is energized in turn the rotor aligns itself with the magnetic field

produced by the energized field winding, Unlike a synchronous motor, in its application, the

the stepper motor may not rotate continuously; instead, it "steps" starts and then quickly stops

team one position to the next as field windings are energized and de-energized in

sequence Depending on the sequence, the rotor may turn forwards or backward, and it may

change direction, stop, speed up or slow down arbitrarily at any time.

Simple stepper motor drivers entirely energize or entirely de-energize the field

things, leading the rotor to "cog" to a limited number of positions, more sophisticated

TRS can proportionally control the power to the field windings, allowing the rotors to

the position between the cog points and thereby rotate extremely smoothly

This mode of operation is often called micro stepping Computer-controlled computer-controlled stepper

motors are one of the most versatile forms of positioning systems, particularly when part of a

digital servo-controlled system.

Stepper motors can be rotated to a specific angle in discrete steps with ease

Stepper motors are used to reading/write head positioning in computer floppy diskette drives.

They were used for the same purpose in pre-gigabyte era computer disk drives, where the

Revision and speed they offered was adequate for the correct the positioning of the read/write

head of a hard disk drive.

As drive density increased, the precision and speed limitations of stepper motors

Quad them obsolete for hard drives--the precision limitation made them unusable, and the (

peed limitation made them the uncompetitive-thus new hard disk drives use voice coil-based

actuator systems. (The term "voice coil" in this the connection is historic; it refers to the

structure in a typical (cone type) loudspeaker.

This structure was used for a while to position the head. Modern drives have a

Posted coil mount; the coil swings back and forth, something like a blade of a rotating fan.

Perpendicular to the magnetic lines of force.)

Nevertheless, like a voice coil, modern actuator coil conductors (the magnet wire) move

Stepper motors were and still are often used in computer printers, optical scanners,

Astrix and inkjet printers), and the platen.

Dn digital photocopier to move the optical scanning element, the print head carriage (of dot

Likewise, many computer plotters (which since the early The 1990s have been replaced

What Large-format inkjet and laser printers) used rotary stepper motors for pen and platen

Movement; the typical alternatives here were either linear a stepper motor or servomotors with

Duplex closed-loop control systems

So-called quartz analog wristwatches contain the smallest commonplace stepping

Motors; they have one coil, draw very little power, and have a permanent magnet rotor. The

Ame kind of motor drives battery-powered quartz clocks. Some of these watches, such as

Chronograph, contain more than one stepping motor.

Stepper motors were upscaled to be used in electric vehicles under the term SRM

Switched reluctance machine).