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André Blondel
André-Eugène Blondel (28 August 1863 – 15 November 1938) was a French engineer and physicist. He is the inventor of the electromechanical oscillograph and a system of photometric units of measurement. Life Blondel was born in Chaumont, Haute-Marne, France. His father was a magistrate from an old family in the town of Dijon. He was the best student from the town in his year. He went on to attend the École nationale des ponts et chaussées (School of Bridges and Roadways) and graduated first in his class in 1888. He was employed as an engineer by the Lighthouses and Beacons Service until he retired in 1927 as its general first class inspector.See IEEE Industry Applications Magazine May–June 2004 He became a professor of electrotechnology at the School of Bridges and Highways and the School of Mines in Paris.See Hebrew University of Jerusalem Very early in his career he suffered immobility due to a paralysis of his legs, which confined him to his room for 27 years, but he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaumont, Haute-Marne
Chaumont () is a commune of France, and the capital (or ''préfecture'') of the Haute-Marne department. , it has a population of 21,847. The city stands on the river Marne and is situated on the Paris-Est–Mulhouse-Ville railway, which runs over a tall and long viaduct built in 1856. Chaumont station has rail connections to Paris, Reims, Dijon, Mulhouse and regional destinations. History Historically, Chaumont was the seat of the Counts of Bassigny and later of Champagne, receiving a charter in 1190. It was the venue of an offensive treaty against Napoleon I signed by the United Kingdom, Austria, Prussia, and Russia in 1814, by which they agreed to continue war until France returned to its 1792 boundaries. Chaumont was bombed in 1940 and 1944 during World War II. From 1951 to 1967, the United States Air Force under NATO operated the Chaumont-Semoutiers Air Base on the outskirts of the city. Notable buildings * The church of St-Jean-Baptiste dates from the 13th centur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dijon
Dijon (, , ) (dated) * it, Digione * la, Diviō or * lmo, Digion is the prefecture of the Côte-d'Or department and of the Bourgogne-Franche-Comté region in northeastern France. the commune had a population of 156,920. The earliest archaeological finds within the city limits of Dijon date to the Neolithic period. Dijon later became a Roman settlement named ''Divio'', located on the road between Lyon and Paris. The province was home to the Dukes of Burgundy from the early 11th until the late 15th centuries, and Dijon became a place of tremendous wealth and power, one of the great European centres of art, learning, and science. The city has retained varied architectural styles from many of the main periods of the past millennium, including Capetian, Gothic, and Renaissance. Many still-inhabited town-houses in the city's central district date from the 18th century and earlier. Dijon's architecture is distinguished by, among other things, '' toits bourguignons'' (Burgu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Power Transmission
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is distinct from the local wiring between high-voltage substations and customers, which is typically referred to as electric power distribution. The combined transmission and distribution network is part of electricity delivery, known as the electrical grid. Efficient long-distance transmission of electric power requires high voltages. This reduces the losses produced by strong currents. Transmission lines use either alternating current (HVAC) or direct current (HVDC). The voltage level is changed with transformers. The voltage is stepped up for transmission, then reduced for local distribution. A wide area synchronous grid, known as an "interconnection" in North America, directly connects generators delivering AC power with the same rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valdemar Poulsen
Valdemar Poulsen (23 November 1869 – 23 July 1942) was a Danish engineer who made significant contributions to early radio technology. He developed a magnetic wire recorder called the telegraphone in 1898 and the first continuous wave radio transmitter, the Poulsen arc transmitter, in 1903, which was used in some of the first broadcasting stations until the early 1920s. Early life Poulsen was born on 23 November 1869 in Copenhagen. He was the son of the Supreme Court judge Jonas Nicolai Johannes Poulsen and Rebekka Magdalene (née Brandt). Recording innovations The magnetic recording was demonstrated in principle as early as 1898 by Poulsen in his telegraphone. Magnetic wire recording, and its successor, magnetic tape recording, involve the use of a magnetizable medium which moves past a recording head. An electrical signal, which is analogous to the sound that is to be recorded, is fed to the recording head, inducing a pattern of magnetization similar to the signa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Duddell
William Du Bois Duddell (1 July 1872, in Kensington, London – 4 November 1917, in Wandsworth, London) was an English physicist and electrical engineer. His inventions include the moving coil oscillograph, as well as the thermo-ammeter and thermo-galvanometer. Life and career Duddell was born William Du Bois to Frances Kate Du Bois, who married George Duddell in 1881. At the age of four he constructed an automaton by combining a toy mouse with clockwork. His younger sister Gladys Duddell was a tennis player. Duddell was privately educated in England and France and rose quickly through the prestigious City & Guilds Schools via scholarships. He died at the age of 45. Duddell's "singing arc" Prior to the invention of the incandescent light bulb, arc lamps were used to light the streets. They created light using an electrical arc between two carbon electrodes. These lamps often produced audible humming, hissing, or even howling sounds. In 1899 Duddell, a student of Wil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Arc
An electric arc, or arc discharge, is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma; the plasma may produce visible light. An arc discharge is characterized by a lower voltage than a glow discharge and relies on thermionic emission of electrons from the electrodes supporting the arc. An archaic term is voltaic arc, as used in the phrase "voltaic arc lamp". Techniques for arc suppression can be used to reduce the duration or likelihood of arc formation. In the late 19th century, electric arc lighting was in wide use for public lighting. Some low-pressure electric arcs are used in many applications. For example, fluorescent tubes, mercury, sodium, and metal-halide lamps are used for lighting; xenon arc lamps have been used for movie projectors. Electric arcs can be utilized for manufacturing processes, such as electric arc welding, and electric arc furnace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rectifier
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The reverse operation (converting DC to AC) is performed by an inverter. The process is known as ''rectification'', since it "straightens" the direction of current. Physically, rectifiers take a number of forms, including vacuum tube diodes, wet chemical cells, mercury-arc valves, stacks of copper and selenium oxide plates, semiconductor diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches. Historically, even synchronous electromechanical switches and motor-generator sets have been used. Early radio receivers, called crystal radios, used a " cat's whisker" of fine wire pressing on a crystal of galena (lead sulfide) to serve as a point-contact rectifier or "crystal detector". Rectifiers have many uses, but are often found serving as components of DC power supplies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternating Current
Alternating current (AC) is an electric current which 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, fans and electric lamps into a wall socket. A common source of DC power is a battery cell in a flashlight. The abbreviations ''AC'' and ''DC'' are often used to mean simply ''alternating'' and ''direct'', as when they modify '' 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. In certain applications, like guitar amplifiers, different waveforms are used, such as triangular waves or square waves. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode Ray Oscilloscope
An oscilloscope (informally a scope) is a type of electronic test instrument that graphically displays varying electrical voltages as a two-dimensional plot of one or more signals as a function of time. The main purposes are to display repetitive or single waveforms on the screen that would otherwise occur too briefly to be perceived by the human eye. The displayed waveform can then be analyzed for properties such as amplitude, frequency, rise time, time interval, distortion, and others. Originally, calculation of these values required manually measuring the waveform against the scales built into the screen of the instrument. Modern digital instruments may calculate and display these properties directly. Oscilloscopes are used in the sciences, medicine, engineering, automotive and the telecommunications industry. General-purpose instruments are used for maintenance of electronic equipment and laboratory work. Special-purpose oscilloscopes may be used to analyze an automotive ign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louisiana Purchase Exposition
The Louisiana Purchase Exposition, informally known as the St. Louis World's Fair, was an World's fair, international exposition held in St. Louis, Missouri, United States, from April 30 to December 1, 1904. Local, state, and federal funds totaling $15 million were used to finance the event. More than 60 countries and 43 of the then-45 American states maintained exhibition spaces at the fair, which was attended by nearly 19.7 million people. Historians generally emphasize the prominence of the themes of Race (human categorization), race and imperialism, and the fair's long-lasting impact on intellectuals in the fields of history, art history, architecture and anthropology. From the point of view of the memory of the average person who attended the fair, it primarily promoted entertainment, consumer goods and popular culture. The monumental Greco-Roman architecture of this and other fairs of the era did much to influence permanent new buildings and master plans of major cities. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soft Iron Oscillograph
Soft may refer to: * Softness, or hardness, a property of physical materials Arts and entertainment * ''Soft!'', a 1988 novel by Rupert Thomson * Soft (band), an American music group * ''Soft'' (album), by Dan Bodan, 2014 * Softs (album), by Soft Machine, 1976 * "Soft", a song by Kings of Leon on the 2004 album ''Aha Shake Heartbreak'' * "Soft"/"Rock", a 2001 single by Lemon Jelly Other uses * Sorgenti di Firenze Trekking (SOFT), a system of walking trails in Italy * Soft matter, a subfield of condensed matter * Magnetically soft, material with low coercivity * Soft skills, a person's people, social, and other skills * Soft commodities, or softs *A flaccid penis Tumescence is the quality or state of being tumescent or swollen. Tumescence usually refers to the normal engorgement with blood (vascular congestion) of the erectile tissues, marking sexual excitation, and possible readiness for sexual activity. ..., the opposite of "hard" See also * * * Softener (disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bifilar Oscillograph
A bifilar coil is an electromagnetic coil that contains two closely spaced, parallel windings. In engineering, the word ''bifilar'' describes wire which is made of two filaments or strands. It is commonly used to denote special types of winding wire for transformers. Wire can be purchased in bifilar form, usually as different colored enameled wire bonded together. For three strands, the term trifilar coil is used. Description and applications The parallel-wound, series connected bifilar coil is how Nikola Teslpatented (512340)it. This way the capacity between the parallel windings is charged by the increased voltage difference (1/2 of the supply voltage) between the series connected windings. This makes it possible for the coil to hold a greatly increased amount of energy in its electric field, and lowers the resonant frequency of the coil drastically. Some bifilars have adjacent coils in which the convolutions are arranged so that the potential difference is magnified (i.e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
