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Mechanical Rectifier
A mechanical rectifier is a device for converting alternating current (AC) to direct current (DC) by means of mechanically operated switches. The best-known type is the commutator, which is an integral part of a DC dynamo, but before solid-state devices became available, independent mechanical rectifiers were used for certain applications. Before the invention of semiconductors, rectification at high currents involved serious losses. There were various vacuum/gas devices, such as the mercury arc rectifiers, thyratrons, ignitrons, and vacuum diodes. Solid-state technology was in its infancy, represented by copper oxide and selenium rectifiers. All of these gave excessive forward voltage drop at high currents. One answer was mechanically opening and closing contacts, if this could be done quickly and cleanly enough. Vibrator type This was the reverse of a vibrator inverter. An electromagnet, powered by DC through contacts it operated (like a buzzer) (or fed with AC), caused ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternating Current
Alternating current (AC) is an electric current that periodically reverses direction and changes its magnitude continuously with time, in contrast to direct current (DC), which flows only in one direction. Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, Fan (machine), fans and electric lamps into a wall socket. The abbreviations ''AC'' and ''DC'' are often used to mean simply ''alternating'' and ''direct'', respectively, as when they modify ''Electric current, current'' or ''voltage''. The usual waveform of alternating current in most electric power circuits is a sine wave, whose positive half-period corresponds with positive direction of the current and vice versa (the full period is called a ''wave cycle, cycle''). "Alternating current" most commonly refers to power distribution, but a wide range of other appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage Regulator
A voltage regulator is a system designed to automatically maintain a constant voltage. It may use a simple feed-forward design or may include negative feedback. It may use an electromechanical mechanism or electronic components. Depending on the design, it may be used to regulate one or more Alternating current, AC or Direct current, DC voltages. Electronic voltage regulators are found in devices such as Power supply unit (computer), computer power supplies where they stabilize the DC voltages used by the processor and other elements. In Alternator (automotive), automobile alternators and central power station generator plants, voltage regulators control the output of the plant. In an electric power distribution system, voltage regulators may be installed at a substation or along distribution lines so that all customers receive steady voltage independent of how much power is drawn from the line. Electronic voltage regulators file:Voltage Regulator connections-en.svg, 250px, Block ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eccentric (mechanism)
In mechanical engineering, an eccentric is a circular disk (''eccentric sheave'') solidly fixed to a rotating axle with its centre offset from that of the axle (hence the word " eccentric", out of the center). It is used most often in steam engines, and used to convert rotary motion into linear reciprocating motion to drive a sliding valve or pump ram. To do so, an eccentric usually has a groove at its circumference closely fitted a circular collar (''eccentric strap''). An attached ''eccentric rod'' is suspended in such a way that its other end can impart the required reciprocating motion. A return crank fulfills the same function except that it can only work at the end of an axle or on the outside of a wheel whereas an eccentric can also be fitted to the body of the axle between the wheels. Unlike a cam, which also converts rotary into linear motion at almost any rate of acceleration and deceleration, an eccentric or return crank can only impart an approximation of simple har ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrolytic Cell
An electrolytic cell is an electrochemical cell that utilizes an external source of electrical energy to force a chemical reaction that would otherwise not occur. The external energy source is a voltage applied between the cell's two electrodes; an anode (positively charged electrode) and a cathode (negatively charged electrode), which are immersed in an electrolyte solution. This is in contrast to a galvanic cell, which itself is a source of electrical energy and the foundation of a battery. The net reaction taking place in an electrolytic cell is a non-spontaneous reaction (reverse of a spontaneous reaction), i.e., the Gibbs free energy is +ve, while the net reaction taking place in a galvanic cell is a spontaneous reaction, i.e., the Gibbs free energy is - ve. Principles In an electrolytic cell, a current passes through the cell by an external voltage, causing a non-spontaneous chemical reaction to proceed. In a galvanic cell, the progress of a spontaneous chemical reacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ampere
The ampere ( , ; symbol: A), often shortened to amp,SI supports only the use of symbols and deprecates the use of abbreviations for units. is the unit of electric current in the International System of Units (SI). One ampere is equal to 1 coulomb (C) moving past a point per second. It is named after French mathematician and physicist André-Marie Ampère (1775–1836), considered the father of electromagnetism along with Danish physicist Hans Christian Ørsted. As of the 2019 revision of the SI, the ampere is defined by fixing the elementary charge to be exactly , which means an ampere is an electric current equivalent to elementary charges moving every seconds, or approximately elementary charges moving in a second. Prior to the redefinition, the ampere was defined as the current passing through two parallel wires 1 metre apart that produces a magnetic force of newtons per metre. The earlier CGS system has two units of current, one structured similarly to the S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volt
The volt (symbol: V) is the unit of electric potential, Voltage#Galvani potential vs. electrochemical potential, electric potential difference (voltage), and electromotive force in the International System of Units, International System of Units (SI). Definition One volt is defined as the electric potential between two points of a electrical conductor, conducting wire when an electric current of one ampere dissipates one watt of power (physics), power between those points. It can be expressed in terms of SI base units (metre, m, kilogram, kg, second, s, and ampere, A) as : \text = \frac = \frac = \frac = \text\text^2\text^. Equivalently, it is the potential difference between two points that will impart one joule of energy per coulomb of charge that passes through it. It can be expressed in terms of SI base units (metre, m, kilogram, kg, second, s, and ampere, A) as : \text = \frac = \frac = \frac = \text\text^2\text^. It can also be expressed as amperes times ohms (curre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-phase Electric Power
Three-phase electric power (abbreviated 3ϕ) is a common type of alternating current (AC) used in electricity generation, transmission, and distribution. It is a type of polyphase system employing three wires (or four including an optional neutral return wire) and is the most common method used by electrical grids worldwide to transfer power. Three-phase electrical power was developed in the 1880s by several people. In three-phase power, the voltage on each wire is 120 degrees phase shifted relative to each of the other wires. Because it is an AC system, it allows the voltages to be easily stepped up using transformers to high voltage for transmission and back down for distribution, giving high efficiency. A three-wire three-phase circuit is usually more economical than an equivalent two-wire single-phase circuit at the same line-to-ground voltage because it uses less conductor material to transmit a given amount of electrical power. Three-phase power is mainly used dire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
England
England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It shares Anglo-Scottish border, a land border with Scotland to the north and England–Wales border, another land border with Wales to the west, and is otherwise surrounded by the North Sea to the east, the English Channel to the south, the Celtic Sea to the south-west, and the Irish Sea to the west. Continental Europe lies to the south-east, and Ireland to the west. At the 2021 United Kingdom census, 2021 census, the population was 56,490,048. London is both List of urban areas in the United Kingdom, the largest city and the Capital city, capital. The area now called England was first inhabited by modern humans during the Upper Paleolithic. It takes its name from the Angles (tribe), Angles, a Germanic peoples, Germanic tribe who settled du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rugby, Warwickshire
Rugby is a market town in eastern Warwickshire, England, close to the River Avon, Warwickshire, River Avon. At the 2021 United Kingdom census, 2021 census, its population was 78,117, making it the List of Warwickshire towns by population, second-largest town in Warwickshire. It is the main settlement within the larger Borough of Rugby, which had a population of 114,400 in 2021. Rugby is situated on the eastern edge of Warwickshire, near to the borders with Leicestershire and Northamptonshire. It is the most easterly town within the West Midlands (region), West Midlands region, with the nearby county borders also marking the regional boundary with the East Midlands. It is north of London, east-south-east of Birmingham, east of Coventry, north-west of Northampton and south-south-west of Leicester. Rugby became a market town in 1255. In 1567, Rugby School was founded as a grammar school for local boys but, by the 18th century, it had gained a national reputation and eventuall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Thomson-Houston
British Thomson-Houston (BTH) was a British engineering and heavy industry, heavy industrial company, based at Rugby, Warwickshire, England. Originally founded to sell products from the Thomson-Houston Electric Company, it soon became a manufacturer using licences from the American company. They were known primarily for their electrical systems and steam turbines. BTH merged with the Metropolitan-Vickers company in 1928 to form Associated Electrical Industries (AEI), but the two brand identities were maintained until 1960. The holding company, AEI, was bought by The General Electric Company, GEC in 1967. In the 1960s AEI's apprenticeships were highly thought-of, both by the apprentices themselves and by their future employers, because they gave the participants valuable experience in the design, production and overall industrial management of a very wide range of electrical products. Over a hundred of the apprentices - who came to Rugby from all over the UK, and a few from abro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Third-brush Dynamo
A third-brush dynamo was a type of dynamo, an electrical generator, formerly used for battery charging on motor vehicles. It was superseded, first by a two-brush dynamo equipped with an external voltage regulator, and later by an alternator. Construction As the name implies, the machine had three brushes in contact with the commutator. One was earthed to the frame of the vehicle and another was connected (through a reverse-current cut-out) to the live terminal of the vehicle's battery. The third was connected to the field winding of the dynamo. The other end of the field winding was connected to a switch which could be adjusted (by inserting or removing resistance) to give "low" or "high" charge. This switch was sometimes combined with the vehicle's light switch so that switching on the headlights simultaneously put the dynamo in high charge mode. Disadvantages The third-brush dynamo had the advantage of simplicity but, by modern standards, it gave poor voltage regulation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Joseph Still
William Joseph Still was an English engineer. He was born at Reigate on 17 August 1870. In 1884, he went to Canada to work for a firm of electric vehicle manufacturers. In 1894, he returned to England, where he invented a double-acting diesel-steam engine in which waste heat from the cylinder jacket and the exhaust was used to produce steam to assist the diesel engine. This is covered by U.S. patent 1230617 of 1917. Still also invented the Still heat-transmitting tube which was used in refrigeration plant. The Still engine The Still engine was used experimentally for stationary, marine and locomotive applications. The best-known application was the Kitson-Still locomotive of 1926 which was tried out on the London and North Eastern Railway The Still engine gave an increase in thermal efficiency over an ordinary diesel engine but was not a long-term success because of the added complexity of the steam system. Patents Still obtained a large number of British, Canadian and U.S. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
