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Magneto (generator)
A magneto is an electrical generator that uses permanent magnets to produce periodic pulses of alternating current. Unlike a dynamo, a magneto does not contain a commutator to produce direct current. It is categorized as a form of alternator, although it is usually considered distinct from most other alternators, which use field coils rather than permanent magnets. Hand-cranked magneto generators were used to provide ringing current in telephone systems. Magnetos were also adapted to produce pulses of high voltage in the ignition systems of some gasoline-powered internal combustion engines to provide power to the spark plugs. Use of such ignition magnetos for ignition is now limited mainly to engines without a low-voltage electrical system, such as lawnmowers and chainsaws, and to aircraft engines, in which keeping the ignition independent of the rest of the electrical system ensures that the engine continues running in the event of alternator or battery failure. For redundancy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chainsaw
A chainsaw (or chain saw) is a portable gasoline-, electric-, or battery-powered saw that cuts with a set of teeth attached to a rotating chain driven along a guide bar. It is used in activities such as tree felling, limbing, bucking, pruning, cutting firebreaks in wildland fire suppression, and harvesting of firewood. Chainsaws with specially designed bar-and-chain combinations have been developed as tools for use in chainsaw art and chainsaw mills. Specialized chainsaws are used for cutting concrete during construction developments. Chainsaws are sometimes used for cutting ice; for example, ice sculpture and winter swimming in Finland. History In surgery The origin of chain saws in surgery is debated. A "flexible saw", consisting of a fine serrated link chain held between two wooden handles, was pioneered in the late 18th century (c. 1783–1785) by two Scottish doctors, John Aitken and James Jeffray, for symphysiotomy and excision of diseased bone, respectively ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elkington Silver Electroplating Works
The Elkington Silver Electroplating Works was a building on Newhall Street in Birmingham, England. It later housed the Birmingham science museum Museum of Science and Industry until the creation of Thinktank. Standing opposite the Birmingham Assay Office, the original 19th century silver electroplating factory of George Elkington, built in 1838, once occupied a much longer, grandiose building on Newhall Street which was largely demolished in the mid-1960s. The works had many workshops and warehouses along and over the Birmingham and Fazeley Canal and the now filled-in Whitmore's Arm (or Miss Colmore's Arm) canal, which ran through the site. In the early 1850s there was a steam-powered electric generator with 64 permanent magnets arranged in a circle and a rotating wrought iron armature. The electroplating process involved solutions of cyanide of silver and potassium cyanide. The building carries two blue plaques on its wall, one to George Elkington, and another to his em ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroplating
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be coated acts as the cathode (negative electrode) of an electrolytic cell; the electrolyte is a solution of a salt of the metal to be coated; and the anode (positive electrode) is usually either a block of that metal, or of some inert conductive material. The current is provided by an external power supply. Electroplating is widely used in industry and decorative arts to improve the surface qualities of objects—such as resistance to abrasion and corrosion, lubricity, reflectivity, electrical conductivity, or appearance. It is used to build up thickness on undersized or worn-out parts, or to manufacture metal plates with complex shape, a process called electroforming. It is used to deposit copper and other conductors in forming pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thinktank, Birmingham Science Museum
Thinktank, Birmingham (formerly known as simply Thinktank) is a science museum in Birmingham, England. Opened in 2001, it is part of Birmingham Museums Trust and is located within the Millennium Point complex on Curzon Street, Digbeth. History The Birmingham Collection of Science & Industry was started in the mid-19th century, initially consisting of collections of weapons from the gun trade and the Birmingham Proof House. The Birmingham Museum & Art Gallery opened in 1885, including science collections. In 1951 the Museum of Science and Industry opened at Elkington Silver Electroplating Works, Newhall Street. Over the following years, the museum acquired individual artefacts, as well as entire collections, that were related to local industry and the history of science and technology. Birmingham City Council decided in 1995 to relocate the museum when it was given an opportunity by the Millennium Commission to construct a new building. The former museum closed in 1997, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woolrich Electrical Generator
The Woolrich Electrical Generator, now in Thinktank, Birmingham Science Museum, England, is the earliest electrical generator used in an industrial process. Built in February 1844 at the Magneto Works of Thomas Prime and Son, Birmingham, to a design by John Stephen Woolrich (1820–1850), it was used by the firm of Elkingtons for commercial electroplating. Plaque The generator stood for some time in the chapel of Aston Hall, accompanied by a plaque bearing the following inscription: Construction The generator in its surviving form consists of 8 axial bobbins with a magnetic field applied by 4 iron horseshoe magnets. The rectangular frame was made of wood and measured 5 foot 4 inches tall, 6 feet wide, and 2 feet long. The generator was fitted with a commutator as electroplating requires direct current. John Stephen Woolrich The generator's designer, John Stephen Woolrich, was born in Lichfield, England in late 1820. The second son of John Woolrich (c.1791–1843) and his w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thinktank Birmingham - Object 1889S00044(2)
A think tank, or policy institute, is a research institute that performs research and advocacy concerning topics such as social policy, political strategy, economics, military, technology, and culture. Most think tanks are non-governmental organizations, but some are semi-autonomous agencies within government or are associated with particular political parties, businesses or the military. Think-tank funding often includes a combination of donations from very wealthy people and those not so wealthy, with many also accepting government grants. Think tanks publish articles and studies, and even draft legislation on particular matters of policy or society. This information is then used by governments, businesses, media organizations, social movements or other interest groups. Think tanks range from those associated with highly academic or scholarly activities to those that are overtly ideological and pushing for particular policies, with a wide range among them in terms of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hippolyte Pixii
Hippolyte Pixii (1808–1835) was an instrument maker from Paris, France. In 1832 he built an early form of alternating current electrical generator, based on the principle of electromagnetic induction discovered by Michael Faraday. Mohamed A. El-Sharkawi, ''Electric Energy: An Introduction, Third Edition'', CRC Press, 2015, ,page 3 Pixii's device was a spinning magnet, operated by a hand crank, where the north and south poles passed over a coil with an iron core. A current pulse was produced each time a pole passed over the coil. He also found that the current direction changed when the north pole passed over the coil after the south pole. Later, acting on a suggestion by André-Marie Ampère, other results were obtained by introducing a commutator which produced a pulsating direct current. At that time direct current was preferable to alternating current. Although Pixii did not fully understand electromagnetic induction, his device led to more sophisticated devices being constru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michael Faraday
Michael Faraday (; 22 September 1791 – 25 August 1867) was an English scientist who contributed to the study of electromagnetism and electrochemistry. His main discoveries include the principles underlying electromagnetic induction, diamagnetism and electrolysis. Although Faraday received little formal education, he was one of the most influential scientists in history. It was by his research on the magnetic field around a conductor carrying a direct current that Faraday established the concept of the electromagnetic field in physics. Faraday also established that magnetism could affect rays of light and that there was an underlying relationship between the two phenomena.. the 1911 Encyclopædia Britannica. He similarly discovered the principles of electromagnetic induction, diamagnetism, and the laws of electrolysis. His inventions of electromagnetic rotary devices formed the foundation of electric motor technology, and it was largely due to his efforts t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Field
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field. A permanent magnet's magnetic field pulls on ferromagnetic materials such as iron, and attracts or repels other magnets. In addition, a nonuniform magnetic field exerts minuscule forces on "nonmagnetic" materials by three other magnetic effects: paramagnetism, diamagnetism, and antiferromagnetism, although these forces are usually so small they can only be detected by laboratory equipment. Magnetic fields surround magnetized materials, and are created by electric currents such as those used in electromagnets, and by electric fields varying in time. Since both strength and direction of a magnetic field may vary with location, it is described mathematically by a function assigning a vector to each point of space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity Generation
Electricity generation is the process of generating electric power from sources of primary energy. For utilities in the electric power industry, it is the stage prior to its delivery ( transmission, distribution, etc.) to end users or its storage (using, for example, the pumped-storage method). Electricity is not freely available in nature, so it must be "produced" (that is, transforming other forms of energy to electricity). Production is carried out in power stations (also called "power plants"). Electricity is most often generated at a power plant by electromechanical generators, primarily driven by heat engines fueled by combustion or nuclear fission but also by other means such as the kinetic energy of flowing water and wind. Other energy sources include solar photovoltaics and geothermal power. There are also exotic and speculative methods to recover energy, such as proposed fusion reactor designs which aim to directly extract energy from intense magnetic fields ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lighthouse
A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lenses and to serve as a beacon for navigational aid, for maritime pilots at sea or on inland waterways. Lighthouses mark dangerous coastlines, hazardous shoals, reefs, rocks, and safe entries to harbors; they also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and has become uneconomical since the advent of much cheaper, more sophisticated and effective electronic navigational systems. History Ancient lighthouses Before the development of clearly defined ports, mariners were guided by fires built on hilltops. Since elevating the fire would improve the visibility, placing the fire on a platform became a practice that led to the development of the lighthouse. In antiquity, the lighthouse functioned more as an entrance marker to ports than as a warning signal for reef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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