Re-Inventing The Wheel ,
here: Re-Inventing The Electric Circuit For Self-Excitation
Let us do a temporal improvement list (if possible including concept papers):
https://en.wikipedia.org/wiki/William_Fothergill_Cookethen studied medicine in Paris, and at
Heidelberg under
Georg Wilhelm Munke. In 1836 he saw electric telegraphy, then only experimental: Munke had illustrated his lectures with a telegraphic apparatus on the principle introduced by
Pavel Schilling in 1835. Cooke decided to put the invention into practical operation with the railway systems; and gave up medicine.
[1]
Early in 1837 Cooke returned to England, with introductions to
Michael Faraday and
Peter Mark Roget. Through them he was introduced to Charles Wheatstone, who in 1834 gave the
Royal Society an account of experiments on the velocity of electricity. Cooke had already constructed a system of telegraphing with three needles on Schilling's principle, and made designs for a mechanical alarm.
https://en.wikipedia.org/wiki/Pavel_Schillinghttps://en.wikipedia.org/wiki/Charles_WheatstoneElectrical generatorsIn 1840, Wheatstone brought out his magneto-electric machine for generating continuous currents.
On 4 February 1867, he published the principle of reaction in the
dynamo-electric machine by a paper to the Royal Society; but Mr. C. W. Siemens had communicated the identical discovery ten days earlier, and both papers were read on the same day.
from Faraday to early motors(and permanent magnets to electro-magnets)
https://en.wikipedia.org/wiki/Electric_motorPerhaps the first electric motors were simple
electrostatic devices created by the Scottish monk
Andrew Gordon in the 1740s.
[2] The theoretical principle behind production of mechanical force by the interactions of an electric current and a magnetic field,
Ampère's force law, was discovered later by
André-Marie Ampère in 1820. The conversion of electrical energy into mechanical energy by
electromagnetic means was demonstrated by the British scientist
Michael Faraday in 1821. A free-hanging wire was dipped into a pool of mercury, on which a
permanent magnet (PM) was placed. When a current was passed through the wire, the wire rotated around the magnet, showing that the current gave rise to a close circular magnetic field around the wire.
[3] This motor is often demonstrated in physics experiments,
brine substituting for toxic mercury. Though
Barlow's wheel was an early refinement to this Faraday demonstration, these and similar
homopolar motors were to remain unsuited to practical application until late in the century.
(https://upload.wikimedia.org/wikipedia/commons/thumb/9/98/Jedlik_motor.jpg/200px-Jedlik_motor.jpg) Jedlik's "electromagnetic self-rotor", 1827 (Museum of Applied Arts, Budapest). The historic motor still works perfectly today.
[4] In 1827,
Hungarian physicist Ányos Jedlik started experimenting with
electromagnetic coils. After Jedlik solved the technical problems of the continuous rotation with the invention of the
commutator, he called his early devices "electromagnetic self-rotors". Although they were used only for instructional purposes, in 1828 Jedlik demonstrated the first device to contain the three main components of practical DC motors: the
stator,
rotor and commutator.
The device employed no permanent magnets, as the magnetic fields of both the stationary and revolving components were produced solely by the currents flowing through their windings.
[5][6][7][8][9][10][11] Success with DC motorsAfter many other more or less successful attempts with relatively weak rotating and reciprocating apparatus the Prussian
Moritz von Jacobi created the first real rotating electric motor in May 1834 that actually developed a remarkable mechanical output power. His motor set a world record which was improved only four years later in September 1838 by Jacobi himself. His second motor was powerful enough to drive a boat with 14 people across a wide river. It was not until 1839/40 that other developers worldwide managed to build motors of similar and later also of higher performance.
The first commutator DC electric motor capable of turning machinery was invented by the British scientist
William Sturgeon in 1832.
[12] Following Sturgeon's work, a commutator-type direct-current electric motor made with the intention of commercial use was built by the American inventor
Thomas Davenport, which he patented in 1837. The motors ran at up to 600 revolutions per minute, and powered machine tools and a printing press.
[13] Due to the high cost of
primary battery power, the motors were commercially unsuccessful and Davenport went bankrupt. Several inventors followed Sturgeon in the development of DC motors but all encountered the same battery power cost issues. No
electricity distribution had been developed at the time. Like Sturgeon's motor, there was no practical commercial market for these motors.
[14]In 1855, Jedlik built a device using similar principles to those used in his electromagnetic self-rotors that was capable of useful work.
[5][11] He built a model
electric vehicle that same year.
[15]A major turning point in the development of DC machines took place in 1864, when Antonio Pacinotti described for the first time the ring armature with its symmetrically grouped coils closed upon themselves and connected to the bars of a commutator, the brushes of which delivered practically non-fluctuating current.
[16][17] The first commercially successful DC motors followed the invention by
Zénobe Gramme who, in 1871, reinvented Pacinotti's design. In 1873, Gramme showed that his dynamo could be used as a motor, which he demonstrated to great effect at exhibitions in Vienna and Philadelphia by connecting two such DC motors at a distance of up to 2 km away from each other, one as a generator.
[18] (See also
1873 : l'expérience décisive [Decisive Workaround] .)
In 1886,
Frank Julian Sprague invented the first practical DC motor, a non-sparking motor that maintained relatively constant speed under variable loads. Other Sprague electric inventions about this time greatly improved grid electric distribution (prior work done while employed by
Thomas Edison), allowed power from electric motors to be returned to the electric grid, provided for electric distribution to trolleys via overhead wires and the trolley pole, and provided controls systems for electric operations. This allowed Sprague to use electric motors to invent the first electric trolley system in 1887–88 in Richmond VA, the electric elevator and control system in 1892, and the electric subway with independently powered centrally controlled cars, which were first installed in 1892 in Chicago by the
South Side Elevated Railway where it became popularly known as the "L". Sprague's motor and related inventions led to an explosion of interest and use in electric motors for industry, while almost simultaneously another great inventor was developing its primary competitor, which would become much more widespread.
The development of electric motors of acceptable efficiency was delayed for several decades by failure to recognize the extreme importance of a relatively small air gap between rotor and stator. Efficient designs have a comparatively small air gap.[19] [a] The
St. Louis motor, long used in classrooms to illustrate motor principles, is extremely inefficient for the same reason, as well as appearing nothing like a modern motor.
[20]
Emergence of AC motors In 1824, the French physicist
François Arago formulated the existence of
rotating magnetic fields, termed
Arago's rotations, which, by manually turning switches on and off, Walter Baily demonstrated in 1879 as in effect the first primitive
induction motor.
[22][23] [24][25] In the 1880s, many inventors were trying to develop workable AC motors
[26] because AC's advantages in long-distance high-voltage transmission were counterbalanced by the inability to operate motors on AC. The first alternating-current commutatorless induction motors were independently invented by
Galileo Ferraris and
Nikola Tesla, a working motor model having been demonstrated by the former in 1885 and by the latter in 1887. In 1888, the Royal Academy of Science of Turin published Ferraris's research detailing the foundations of motor operation while however concluding that "the apparatus based on that principle could not be of any commercial importance as motor."
[25][27][28][29][30][31][32][33][34][35][36][37][38] In 1888, Tesla presented his paper A New System for Alternating Current Motors and Transformers to the AIEE that described 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. One of the patents Tesla filed in 1887, however, also described a shorted-winding-rotor induction motor.
George Westinghouse promptly bought Tesla's patents, employed Tesla to develop them, and assigned
C. F. Scott to help Tesla; however, Tesla left for other pursuits in 1889.
[25][32][35][36][37][38][39][40][41][42] [43][44][45][46] The constant speed AC induction motor was found not to be suitable for street cars
[26] but Westinghouse engineers successfully adapted it to power a mining operation in Telluride, Colorado in 1891.
[47][48][49] Steadfast in his promotion of three-phase development,
Mikhail Dolivo-Dobrovolsky invented the three-phase cage-rotor induction motor in 1889 and the
three-limb transformer in 1890. This type of motor is now used for the vast majority of commercial applications.
[50][51] However, he claimed that Tesla's motor was not practical because of two-phase pulsations, which prompted him to persist in his three-phase work.
[52] Although Westinghouse achieved its first practical induction motor in 1892 and developed a line of polyphase 60 hertz induction motors in 1893, these early Westinghouse motors were
two-phase motors with wound rotors until
B. G. Lamme developed a rotating bar winding rotor.
[39] The
General Electric Company began developing three-phase induction motors in 1891.
[39] By 1896, General Electric and Westinghouse signed a cross-licensing agreement for the bar-winding-rotor design, later called the
squirrel-cage rotor.
[39] Induction motor improvements flowing from these inventions and innovations were such that a 100
horsepower (HP) induction motor currently has the same mounting dimensions as a 7.5 HP motor in 1897.
[39]
https://de.images.search.yahoo.com/search/images;_ylt=A9mSs2PIGcBXs6sAGF8zCQx.;_ylu=X3oDMTByZmVxM3N0BGNvbG8DaXIyBHBvcwMxBHZ0aWQDBHNlYwNzYw--?p=Self-excited+Magnetic+Field&fr=mcafee
http://circuitglobe.com/types-of-dc-generator-separately-excited-and-self-excited.html
https://en.wikipedia.org/wiki/Transformer
https://en.wikipedia.org/wiki/Electromagnet
https://en.wikipedia.org/wiki/Magnet
http://rexresearch.com/mrmagnet/mrmagnet.htm
(enter the PDF)
page 18: steady magnetic field/ rotating magnetic field : voltage !
http://www.tuks.nl/pdf/Eric_Dollard_Document_Collection/Rotating%20Magnetic%20Field.pdf
https://en.wikipedia.org/wiki/Felix_Ehrenhaft