Electric motors have a long history going back to the early nineteenth century.
|Date, Name||Electric Motor Chronology||Selected Patents|
|1740s, Andrew Gordon and Benjamin Franklin||British (Gordon), American (Franklin); experimentation with electrostatic motors.|
|1820, Hans Christian Ørsted||Danish, physicist and chemist; first to note a compass needle deflected from magnetic north when an electric current from a battery was switched on and off, confirming a direct relationship between electricity and magnetism.|
|1820, André-Marie Ampère||French, physicist; invented the solenoid.|
|1821 Michael Faraday||British, scientist; showed continuous 'electromagnetic rotation' resulted by suspending a magnetic wire in an electric field;|
|1822, Peter Barlow||British, physicist; invented Barlow's wheel, the first device ever powered by electromagnetism.|
|1824, François Arago||French, physicist; showed a rotating copper disk produced rotation in a magnetic needle suspended above it, which Faraday later attributed to induction phenomena.|
|1828, Ányos Jedlik||Hungarian, physicist and unsung father of the dynamo and electric motor; invented the first commutated rotary electromechanical machine with electromagnets. He invented the commutator. In 1828 Jedlik demonstrated the first device to contain the three main components of practical DC motors: the stator, rotor and commutator.|
|Before 1830, Johann Michael Ekling||Austrian, mechanic; constructed an electric motor according to the plans of Austrian physicist Andreas von Baumgartner.|
|1831 Michael Faraday||British, scientist; discovered and investigated induction law in terms of electric current generation in a varying magnetic field.|
|1831, Joseph Henry||American, physicist; Created a mechanical rocker, which he however describes as a philosophical toy.|
|1825-1833 William Sturgeon||British, scientist; 1825 - invented the electro-magnet; 1833 - built first commutated rotating electric machine that was demonstrated in London.|
|1832–33, Hippolyte Pixii||French, instrument maker, built the first AC generating apparatus out of a rotation; and, the following year, an oscillating DC generator.|
|1833, Joseph Saxton||American, inventor; demonstrated a magneto-electric machine before the British Association for the Advancement of Science.|
|1833, Heinrich Friedrich Emil Lenz||German; formulated the law of reversibility of generators and motors.|
|1834–1839, Moritz von Jacobi||German-Russian, engineer and physicist; built a 15 watt motor in 1834 submitted to the Academy of Sciences in Paris with details published in 1835; demonstrated first use of electric motor to propel a boat; first real useful rotary electrical motor.|
|1837, Thomas Davenport and Emily Davenport||American, blacksmith-inventor and inventor; obtained first US electric motor patent.||US 132|
|1837–1842, Robert Davidson||Scottish, inventor; developed electric motors for a lathe and a locomotive.|
|1838, Solomon Stimpson||American; built a 12-pole electric motor with segmental commutator.||US 910|
|1840, Truman Cook||American; built electric motor with a PM armature.||US 1735|
|1845, Paul-Gustav Froment||French, engineer and instrument maker; first of various motors; first motor translated linear "electromagnetic piston's" energy to wheel's rotary motion. See also Mouse mill motor.|
|1856, Werner Siemens||German, industrialist; invented generator with a double-T armature and slots windings.|
|1861–1864, James Clerk Maxwell||British, scientist; reduced electromagnetism knowledge in four key equations.|
|1871–1873, Zénobe Théophile Gramme||Belgian, engineer; developed the anchor ring motor which solved the double-T armature pulsating DC problem; at Vienna exhibition, demonstrated to great effect ability to transmit between generator and motor 1 km apart.|
|1879, Walter Baily||British; based on Arago's rotations, by manual switching on and off, developed the first primitive commutatorless induction motor.|
|1880, Marcel Deprez||French engineer; by the progressive shifting of a magnetic field through the mechanical commutator in regular order around a center, electric currents are being developed by induction in a rotating metal mass without sliding contacts or commutator.|
|1885, Galileo Ferraris||Italian, physicist and engineer; invented the first AC commutatorless induction motor using two-phase AC windings in space quadrature. Delivered a paper on it in April 1888.|
|1887, M. Borel||Constructed a two phase motor where the rotor is set in rotation by the combined rotating field produced with two sets of coils.|
|1887, Helios Co.||Based on Coerper's patent, Helios Co. constructed the first 3-phase motor with three slip-rings. The project was dropped in 1890 as they could get satisfactory results using a 2-phase current.|
|1887, Friedrich August Haselwander||Friedrich August Haselwander develops the first AC 3 phase synchronous generator in Europe. The patent application filed in July 1887. His first generator of this type went into operation in October 1887.|
|1887, Charles S. Bradley||Motor/generators with a Gramme ring, having multiple radial connectors, led off at corresponding symmetrical points to slip-rings. He thus obtained alternate currents differing in phase.||US390439A|
|1887–1891, Nikola Tesla||Serbian-American, engineer and inventor; having worked independently from Ferraris, presented a paper in May, 1888 to AIEE describing three patented two-phase four-stator-pole motor types: one with a four-pole rotor forming a non-self-starting reluctance motor, another with a wound rotor forming a self-starting induction motor, and the third a true synchronous motor with separately-excited DC supply to rotor winding. Westinghouse acquired exclusive rights to the Tesla patents as well as the Ferraris design and retain Tesla as a consultant for a short time to work on development of these motors.|| US 0,381,968 |
|1886, Frank Julian Sprague||American, industrialist; development of new constant-speed DC motor, which allowed the Sprague company to issue the world's "first important industrial electric motor catalogue".|
|1889–90, Mikhail Dolivo-Dobrovolsky||Polish-Russian, engineer and inventor; invented the first cage and wound rotor versions of the three-phase induction motor that are still widely in use today.|
|Date, Name||Electric Motor Chronology||Selected Patents|
|1905, Alfred Zehden||German, a feasible linear induction motor described in patent form for driving trains or lifts.||U.S. Patent 782,312|
|1935, Hermann Kemper||German, built a working linear induction motor|
|1945–1949, Eric Laithwaite||British, first full-size working model of linear induction motor|
Charles Proteus Steinmetz was a German-American mathematician and electrical engineer and professor at Union College. He fostered the development of alternating current that made possible the expansion of the electric power industry in the United States, formulating mathematical theories for engineers. He made ground-breaking discoveries in the understanding of hysteresis that enabled engineers to design better electromagnetic apparatus equipment, especially electric motors for use in industry.
George Westinghouse Jr. was an American entrepreneur and engineer based in Pennsylvania who created the railway air brake and was a pioneer of the electrical industry, receiving his first patent at the age of 19. Westinghouse saw the potential of using alternating current for electric power distribution in the early 1880s and put all his resources into developing and marketing it. This put Westinghouse's business in direct competition with Thomas Edison, who marketed direct current for electric power distribution. In 1911 Westinghouse received the American Institute of Electrical Engineers's (AIEE) Edison Medal "For meritorious achievement in connection with the development of the alternating current system." He founded the Westinghouse Electric Corporation in 1886.
An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied on the motor's shaft. An electric generator is mechanically identical to an electric motor, but operates with a reversed flow of power, converting mechanical energy into electrical energy.
In electricity generation, a generator is a device that converts motion-based power or fuel-based power into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. Generators provide nearly all the power for electrical grids.
An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature. Occasionally, a linear alternator or a rotating armature with a stationary magnetic field is used. In principle, any AC electrical generator can be called an alternator, but usually the term refers to small rotating machines driven by automotive and other internal combustion engines.
An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor can therefore be made without electrical connections to the rotor. An induction motor's rotor can be either wound type or squirrel-cage type.
A rotating magnetic field is the resultant magnetic field produced by a system of coils symmetrically placed and supplied with polyphase currents. A rotating magnetic field can be produced by a poly-phase current or by a single phase current provided that, in the latter case, two field windings are supplied and are so designed that the two resulting magnetic fields generated thereby are out of phase.
A polyphase system is a means of distributing alternating-current (AC) electrical power where the power transfer is constant during each electrical cycle. AC phase refers to the phase offset value between AC in multiple conducting wires; phases may also refer to the corresponding terminals and conductors, as in color codes. Polyphase systems have three or more energized electrical conductors carrying alternating currents with a defined phase between the voltage waves in each conductor; for three-phase voltage, the phase angle is 120° or 2π/3 radians. Polyphase systems are particularly useful for transmitting power to electric motors which rely on alternating current to rotate. The most common example is the three-phase power system used for industrial applications and for power transmission. Compared to a single-phase, two-wire system, a three-phase three-wire system transmits three times as much power for the same conductor size and voltage.
Power engineering, also called power systems engineering, is a subfield of electrical engineering that deals with the generation, transmission, distribution, and utilization of electric power, and the electrical apparatus connected to such systems. Although much of the field is concerned with the problems of three-phase AC power – the standard for large-scale power transmission and distribution across the modern world – a significant fraction of the field is concerned with the conversion between AC and DC power and the development of specialized power systems such as those used in aircraft or for electric railway networks. Power engineering draws the majority of its theoretical base from electrical engineering and mechanical engineering.
Silvanus Phillips Thompson was an English professor of physics at the City and Guilds Technical College in Finsbury, England. He was elected to the Royal Society in 1891 and was known for his work as an electrical engineer and as an author. Thompson's most enduring publication is his 1910 text Calculus Made Easy, which teaches the fundamentals of infinitesimal calculus, and is still in print. Thompson also wrote a popular physics text, Elementary Lessons in Electricity and Magnetism, as well as biographies of Lord Kelvin and Michael Faraday.
Galileo Ferraris was an Italian university professor, physicist and electrical engineer, one of the pioneers of AC power system and inventor of the induction motor although he never patented his work. Many newspapers touted that his work on the induction motor and power transmission systems were some of the greatest inventions of all ages. He published an extensive and complete monograph on the experimental results obtained with open-circuit transformers of the type designed by the power engineers Lucien Gaulard and John Dixon Gibbs.
This is an alphabetical list of articles pertaining specifically to electrical and electronics engineering. For a thematic list, please see List of electrical engineering topics. For a broad overview of engineering, see List of engineering topics. For biographies, see List of engineers.
Ányos István Jedlik was a Hungarian inventor, engineer, physicist, and Benedictine priest. He was also a member of the Hungarian Academy of Sciences, and author of several books. He is considered by Hungarians and Slovaks to be the unsung father of the dynamo and electric motor.
An AC motor is an electric motor driven by an alternating current (AC). The AC motor commonly consists of two basic parts, an outside stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft producing a second rotating magnetic field. The rotor magnetic field may be produced by permanent magnets, reluctance saliency, or DC or AC electrical windings.
The history of electromagnetic theory begins with ancient measures to understand atmospheric electricity, in particular lightning. People then had little understanding of electricity, and were unable to explain the phenomena. Scientific understanding into the nature of electricity grew throughout the eighteenth and nineteenth centuries through the work of researchers such as Coulomb, Ampère, Faraday and Maxwell.
A dynamo is an electrical generator that creates direct current using a commutator. Dynamos were the first electrical generators capable of delivering power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the electric motor, the alternating-current alternator, and the rotary converter.
The 1891 International Electrotechnical Exhibition was held between 16 May and 19 October on the disused site of the three former Westbahnhöfe in Frankfurt am Main, Germany. The exhibition featured the first long-distance transmission of high-power, three-phase electric current, which was generated 175 km away at Lauffen am Neckar. As a result of this successful field trial, three-phase current became established for electrical transmission networks throughout the world.
René Thury was a Swiss pioneer in electrical engineering. He was known for his work with high voltage direct current electricity transmission and was known in the professional world as the "King of DC."
Arago's rotations is an observable magnetic phenomenon that involves the interactions between a magnetized needle and a moving metal disk. The effect was discovered by François Arago in 1824. At the time of their discovery, Arago's rotations were surprising effects that were difficult to explain. In 1831, Michael Faraday introduced the theory of electromagnetic induction, which explained how the effects happen in detail.
Walter Bailys Polyphase motor (1879) marks the beginning of the development of modern polyphase motors. Mr. Bailey exhibited his invention on the Physical Society of London on June 28, 1879, on the occasion of his reading a paper entitled, "A Mode of Producing Arago's Rotations."