Moritz Hermann von Jacobi

Moritz Hermann (Boris Semyonovich) von Jacobi (Russian: Борис Семёнович (Морис-Герман) Якоби) (September 21, 1801 – March 10, 1874) was a Prussian engineer and physicist born in Potsdam. Jacobi worked mainly in Russia. He furthered progress in galvanoplastics, electric motors, and wire telegraphy. Image File history File links Download high-resolution version (600x819, 116 KB) Title: Moritz Hermann von Jacobi Year: 1856 Source: http://www. ... Image File history File links Download high-resolution version (600x819, 116 KB) Title: Moritz Hermann von Jacobi Year: 1856 Source: http://www. ... September 21 is the 264th day of the year (265th in leap years). ... The Union Jack, flag of the newly formed United Kingdom of Great Britain and Ireland. ... March 10 is the 69th day of the year in the Gregorian Calendar (70th in leap years). ... 1874 (MDCCCLXXIV) was a common year starting on Thursday (see link for calendar). ... Coat of Arms of the Kingdom of Prussia, 1701-1918 Prussia (German: ; Latin: Borussia, Prutenia; Lithuanian: ; Polish: ; Old Prussian: PrÅ«sa) was, most recently, a historic state originating in East Prussia, an area which for centuries had substantial influence on German and European history. ... Potsdam is the capital city of the state of Brandenburg in Germany. ... Electrotyping is an application of the art of electroplating to typography, used for making duplicate plates for relief printing (letterpress). ... Rotating magnetic field as a sum of magnetic vectors from 3 phase coils. ... A wire is a single, usually cylindrical, elongated strand of drawn metal. ... Optical Telegraf of Claude Chappe on the Litermont near Nalbach, Germany Telegraph and telegram redirect here. ...

Motors

In 1834 he began to study magnetic motors. In 1835 moved to Derpt to lecture at Derpt University. He moved to St. Petersburg in 1837 to research usage of electromagnetic forces for moving machines for Russian Academy of Sciences. He investigated the power of an electromagnet in motors and generators. While studying the transfer of power from a battery to an electric motor, he deduced the maximum power theorem. Jacobi tested motors output by determining the amount of zinc consumed by the battery. With financial assistance of Czar Nicholas, Jacobi constructed in 1839 a 28 foot electric motor boat powered by battery cells. The boat carried 14 passengers on Neva river against the current. The boat travelled at the speed of three miles per hour. Rotating magnetic field as a sum of magnetic vectors from 3 phase coils. ... | Come and take it, slogan of the Texas Revolution 1835 was a common year starting on Thursday (see link for calendar). ... Image of Tartu street Tartu (German, Polish Dorpat, Russian Юpьeв Yuryev) is the second largest city of Estonia, with its population of 101,246 (the Population Census data is from 2000) in an area of 38. ... The University of Tartu (Estonian: Tartu Ãœlikool, German: Universität Dorpat) is the national university of Estonia, and the one classical university in Estonia, located in the city of Tartu. ... Saint Petersburg (Russian: Санкт-Петербу́рг, English transliteration: Sankt-Peterburg), colloquially known as Питер (transliterated Piter), formerly known as Leningrad (Ленингра́д, 1924–1991) and... | Queen Victoria, Queen of the United Kingdom (1837 - 1901) 1837 was a common year starting on Sunday (see link for calendar). ... Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. ... Russian Academy of Sciences: main building Russian Academy of Sciences (Росси́йская Акаде́мия Нау́к) is the national academy of Russia. ... This article or section does not cite its references or sources. ... In electrical engineering, the maximum power (transfer) theorem states that to obtain maximum power from a source with a fixed internal resistance the resistance of the load must be made the same as that of the source. ... Nicholas I Pavlovich (Russian: Николай I Павлович, July 6 (June 25, Old Style), 1796–March 2 (February 18, Old Style), 1855) was the Emperor of Russia and king of Poland from 1825 until his death in... 1839 was a common year starting on Tuesday (see link for calendar). ... This article or section does not cite its references or sources. ... The River Neva (Russian: Нева́) is a 74 km-long Russian river flowing from Lake Ladoga (Ладожское Озеро, Ladožskoe Ozero) through the Karelian Isthmus (Карельский Перешеек, Karelskij PereÅ¡eek) and the city of Saint Petersburg (Санкт-Петербург, Sankt-Peterburg) to the Gulf of Finland (Финский Залив, Finskij Zaliv). ... Speed is the rate of motion, or equivalently the rate of change of position, many times expressed as distance d moved per unit of time t. ... Miles per hour is a unit of speed, expressing the number of international miles covered per hour. ...

Jacobi's Law

Circuit Diagram

Power is being transferred from the source,
with voltage V and resistance R_S,
to a load with resistance R_L,
resulting in a current I. I is simply
the source voltage divided by the total Image File history File links Maxpowertheorem. ...

circuit resistance

The law known as the maximum power theorem states: In electrical engineering, the maximum power (transfer) theorem states that to obtain maximum power from a source with a fixed internal resistance the resistance of the load must be made the same as that of the source. ...

"Maximum power is transferred when the internal resistance of the source equals the resistance of the load, when the external resistance can be varied, and the internal resistance is constant."

The transfer of maximum power from a source with a fixed internal resistance to a load, the resistance of the load must be the same as that of the source. This law is of use when driving a load such as an electric motor from a battery. Jacobi obtained his theorem by common sense. A theorem is a proposition that has been or is to be proved on the basis of explicit assumptions. ... Look up Common sense in Wiktionary, the free dictionary. ...

Electrotyping and telegraphy

In 1838, he discovered galvanoplastics, or electrotyping, a method of making printing plates by electroplating. The way in which this works is analogous to a battery acting in reverse. The stereotype was an impression taken from a form of movable lead type and used for printing instead of the original type. This technique is used in relief printing. | Jöns Jakob Berzelius, discoverer of protein 1838 was a common year starting on Monday (see link for calendar). ... Electroplating is the coating of an electrically conductive item with a layer of metal using electrical current. ... Theli34 11:30, 19 November 2006 (UTC) 11:29, 19 November 2006 (UTC) This article or section does not cite its references or sources. ...

He also worked on the development of the electric telegraph. In 1842-1845 he built a telegraph line between Saint Petersburg and Tsarskoe Selo using an underground cable. In 1867 he was a Russian delegate to the Commission on measurement units at the Paris World's Fair. He was a strong proponent of the metric system. Telegraphy (from the Greek words tele = far away and grapho = write) is the long distance transmission of written messages without physical transport of letters, originally over wire. ... 1842 was a common year starting on Saturday (see link for calendar). ... 1845 was a common year starting on Wednesday (see link for calendar). ... Saint Petersburg (Russian: Санкт-Петербу́рг, English transliteration: Sankt-Peterburg), colloquially known as Питер (transliterated Piter), formerly known as Leningrad (Ленингра́д, 1924–1991) and... Tsarskoye Selo (Царское Село in Russian, may be translated as “Tsar’s Village”), a former residence of the royal families and visiting nobility 24 km south of St. ... 1867 (MDCCCLXVII) was a common year starting on Tuesday (see link for calendar). ... City flag City coat of arms Motto: Fluctuat nec mergitur (Latin: Tossed by the waves, she does not sink) Location Coordinates Time Zone CET (GMT +1) Administration Country France Région ÃŽle-de-France Département Paris (75) Subdivisions 20 arrondissements Mayor Bertrand Delanoë  (PS) (since 2001) City Statistics Land... A Worlds Fair is any of various large expositions held since the mid-19th century. ... The International System of Units (symbol: SI) (for the French phrase Syst me International dUnit s) is the most widely used system of units. ...

External links

Wikimedia Commons has media related to:

Moritz Hermann von Jacobi

• Katz, Eugenii, "Moritz Hermann Jacobi". Biosensors & Bioelectronics.
• Calvert, J. B., "Jacobi's Theorem Also known as the Maximum Power Transfer Theorem, misunderstanding of it retarded development of dynamos". March 30, 2001