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George Henry Bachhoffner
George Henry Bachhoffner (13 April 1810 – 22 July 1879), was a British scientist, one of the founders of the London Polytechnic Institution, and a lecturer on scientific subjects. Bachhoffner was a native of London. He married Caroline Derby on 23 July 1834 at St Pancras Old Church. It was in 1837 that he, in conjunction with a few others, established the Polytechnic, which was intended for a place of popular instruction. Here, he held the position of principal of the department of natural and experimental philosophy until 1855. Afterwards, he became lessee and manager of the Coliseum in the Regent's Park, and there gave lectures similar to the courses he had established at the Polytechnic. In the later part of his life, he held a post as registrar of births and deaths in Marylebone. Bachhoffner was an inventor and took out several patents for inventions connected with the electric telegraph, gas stoves and oil lamps. He was a member of the London Electrical Society. In expe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
London Polytechnic Institution
, mottoeng = The Lord is our Strength , type = Public , established = 1838: Royal Polytechnic Institution 1891: Polytechnic-Regent Street 1970: Polytechnic of Central London 1992: University of Westminster , endowment = £5.1 million , budget = £205.1 million , chancellor = Lady Sorrell , vice_chancellor = Peter Bonfield , students = () , undergrad = () , postgrad = () , city = London , country = United Kingdom , colours = Royal blue, Fuchsia , website www.westminster.ac.uk, logo = Navbar-westminster-logo.svg , affiliations = The University of Westminster is a public university based in London, United Kingdom. Founded in 1838 as the Royal Polytechnic Institution, it was the first polytechnic to open in London. The Polytechnic formally received a Royal charter in August 1839, and became the University of Westminster in 1992. Westminster has its main campus in Regent Street in central London, with additional campuses in Fitzrovia, Marylebone a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marylebone
Marylebone (usually , also , ) is a district in the West End of London, in the City of Westminster. Oxford Street, Europe's busiest shopping street, forms its southern boundary. An ancient parish and latterly a metropolitan borough, it merged with the boroughs of Westminster and Paddington to form the new City of Westminster in 1965. Marylebone station lies two miles north-west of Charing Cross. History Marylebone was originally an Ancient Parish formed to serve the manors (landholdings) of Lileston (in the west, which gives its name to modern Lisson Grove) and Tyburn in the east. The parish is likely to have been in place since at least the twelfth century and will have used the boundaries of the pre-existing manors. The boundaries of the parish were consistent from the late twelfth century to the creation of the Metropolitan Borough which succeeded it. Etymology The parish took its name from its church, dedicated to St Mary; the original church was built on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Telegraph
Electrical telegraphs were point-to-point text messaging systems, primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications system and the most widely used of a number of early messaging systems called '' telegraphs'', that were devised to communicate text messages quicker than physical transportation. Electrical telegraphy can be considered to be the first example of electrical engineering. Text telegraphy consisted of two or more geographically separated stations, called telegraph offices. The offices were connected by wires, usually supported overhead on utility poles. Many different electrical telegraph systems were invented, but the ones that became widespread fit into two broad categories. The first category consists of needle telegraphs in which a needle pointer is made to move electromagnetically with an electric current sent down the telegraph line. Early systems used multiple needles requiring multiple wires. The f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Stove
A gas stove is a stove that is fuelled by combustible gas such as syngas, natural gas, propane, butane, liquefied petroleum gas or other flammable gas. Before the advent of gas, cooking stoves relied on solid fuels such as coal or wood. The first gas stoves were developed in the 1821s and a gas stove factory was established in England in 1836. This new cooking technology had the advantage of being easily adjustable and could be turned off when not in use. The gas stove, however, did not become a commercial success until the 1885s, by which time supplies of piped gas were available in cities and large towns in Britain. The stoves became widespread on the European Continent and in the United States in the middle 20th century. Gas stoves became more common when the oven was integrated into the base and the size was reduced to better fit in with the rest of the kitchen furniture. By the 1910s, producers started to enamel their gas stoves for easier cleaning. Ignition of the gas wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Lamp
An oil lamp is a lamp used to produce light continuously for a period of time using an oil-based fuel source. The use of oil lamps began thousands of years ago and continues to this day, although their use is less common in modern times. They work in the same way as a candle but with fuel that is liquid at room temperature, so that a container for the oil is required. A textile wick drops down into the oil, and is lit at the end, burning the oil as it is drawn up the wick. Oil lamps are a form of lighting, and were used as an alternative to candles before the use of electric lights. Starting in 1780, the Argand lamp quickly replaced other oil lamps still in their basic ancient form. These in turn were replaced by the kerosene lamp in about 1850. In small towns and rural areas the latter continued in use well into the 20th century, until such areas were finally electrified and light bulbs could be used. Sources of fuel for oil lamps include a wide variety of plants such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
London Electrical Society
The London Electrical Society was established in 1837 to enable amateur electricians to meet and share their interests in “experimental investigation of Electrical Science in all its various branches”. Although it initially flourished the society soon showed weaknesses in its organisation and ways of working. After a period of considerable financial difficulty it closed in 1845. Rise and fall The London Electrical Society was founded at a meeting held on 16 May 1837 at Edward M Clarke's “Laboratory of Science” in Lowther Arcade, near the Strand. The idea for the Society had arisen from discussions during a course of lectures on electricity delivered by William Sturgeon at the same venue. He was assisted in establishing the Society by operative chemist William Leithead; John Peter Gassiot, an amateur scientist with a particular interest in electricity; and Charles Vincent Walker, an electrical engineer. The London Electrical Society's aim was to provide a forum for amateur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induction Coil
An induction coil or "spark coil" ( archaically known as an inductorium or Ruhmkorff coil after Heinrich Rühmkorff) is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current (DC) supply. p.98 To create the flux changes necessary to induce voltage in the secondary coil, the direct current in the primary coil is repeatedly interrupted by a vibrating mechanical contact called an interrupter. Invented in 1836 by Nicholas Callan, with additional research by Charles Grafton Page and others, the induction coil was the first type of transformer. It was widely used in x-ray machines, spark-gap radio transmitters, arc lighting and quack medical electrotherapy devices from the 1880s to the 1920s. Today its only common use is as the ignition coils in internal combustion engines and in physics education to demonstrate induction. Construction and function An induction coil consists of two coils of insulated wire wound around a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Core
A magnetic core is a piece of magnetic material with a high magnetic permeability used to confine and guide magnetic fields in electrical, electromechanical and magnetic devices such as electromagnets, transformers, electric motors, generators, inductors, magnetic recording heads, and magnetic assemblies. It is made of ferromagnetic metal such as iron, or ferrimagnetic compounds such as ferrites. The high permeability, relative to the surrounding air, causes the magnetic field lines to be concentrated in the core material. The magnetic field is often created by a current-carrying coil of wire around the core. The use of a magnetic core can increase the strength of magnetic field in an electromagnetic coil by a factor of several hundred times what it would be without the core. However, magnetic cores have side effects which must be taken into account. In alternating current (AC) devices they cause energy losses, called core losses, due to hysteresis and eddy currents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eddy Current
Eddy currents (also called Foucault's currents) are loops of electrical current induced within conductors by a changing magnetic field in the conductor according to Faraday's law of induction or by the relative motion of a conductor in a magnetic field. Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic field. They can be induced within nearby stationary conductors by a time-varying magnetic field created by an AC electromagnet or transformer, for example, or by relative motion between a magnet and a nearby conductor. The magnitude of the current in a given loop is proportional to the strength of the magnetic field, the area of the loop, and the rate of change of flux, and inversely proportional to the resistivity of the material. When graphed, these circular currents within a piece of metal look vaguely like eddies or whirlpools in a liquid. By Lenz's law, an eddy current creates a magnetic field that opposes the change in the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transformer
A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer's core, which induces a varying electromotive force (EMF) across any other coils wound around the same core. Electrical energy can be transferred between separate coils without a metallic (conductive) connection between the two circuits. Faraday's law of induction, discovered in 1831, describes the induced voltage effect in any coil due to a changing magnetic flux encircled by the coil. Transformers are used to change AC voltage levels, such transformers being termed step-up or step-down type to increase or decrease voltage level, respectively. Transformers can also be used to provide galvanic isolation between circuits as well as to couple stages of signal-processing circuits. Since the invention of the first constant-potential transf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laminated Core
A magnetic core is a piece of magnetic material with a high magnetic permeability used to confine and guide magnetic fields in electrical, electromechanical and magnetic devices such as electromagnets, transformers, electric motors, generators, inductors, magnetic recording heads, and magnetic assemblies. It is made of ferromagnetic metal such as iron, or ferrimagnetic compounds such as ferrites. The high permeability, relative to the surrounding air, causes the magnetic field lines to be concentrated in the core material. The magnetic field is often created by a current-carrying coil of wire around the core. The use of a magnetic core can increase the strength of magnetic field in an electromagnetic coil by a factor of several hundred times what it would be without the core. However, magnetic cores have side effects which must be taken into account. In alternating current (AC) devices they cause energy losses, called core losses, due to hysteresis and eddy currents in appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inductor
An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. An inductor typically consists of an insulated wire wound into a coil. When the current flowing through the coil changes, the time-varying magnetic field induces an electromotive force (''emf'') (voltage) in the conductor, described by Faraday's law of induction. According to Lenz's law, the induced voltage has a polarity (direction) which opposes the change in current that created it. As a result, inductors oppose any changes in current through them. An inductor is characterized by its inductance, which is the ratio of the voltage to the rate of change of current. In the International System of Units (SI), the unit of inductance is the henry (H) named for 19th century American scientist Joseph Henry. In the measurement of magnetic circuits, it is equivalent to . Inductors have values that typical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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