Alternating current : electrical engineering

Scientists and engineers frequently use diagrams to schematically represent electric circuits. A circuit exists when charge is able to flow around a closed path. There are two types of circuits direct current (DC) circuits and alternating current (AC) circuits. In DC circuits the current flows in one direction only, while in AC circuits the current periodically changes direction. DC circuits commonly use batteries, whereas most AC circuits get their energy from wall outlets or AC generators. We will discuss only DC circuits in detail in this textbook. 

Among those who thought hard on the subject—indeed, they were the first into the field in a big way—were researchers at the Westinghouse Electric Corporation. Named for the American inventor and engineer, George Westing-house, a pioneer in the introduction of alternating-current power in the United States (and whose first invention of... 

Engineers understand the importance of electricity and electrical power and the role they play in our everyday lives. As future engineers you should know what is meant by voltage, electric current, and know the difference between direct and alternating current You should also know the various sources of electricity and understand how electricity is generated. 

Chemists often reason in terms of dielectric permittivity (e) or infrared spectra (a) while electrical engineers and physicists consider tangent loss (tg = e"/s ) and alternative current conductivity (free charges (where the complex impedance formalism is well-suited) and bound charges (where the description of the permittivity s = e (co) — ie"(co) is more suitable) can be distinguished. Such a distinction is not straightforward in superionic conductors, however, in which some conducting species are in a quasi-liquid state and in particular, for proton conductors. In the latter, the proton (attached... 

With the establishment of an electrical grid, based on the advocacy of alternating current by Serbian American engineer and inventor Nikola Tesla (1856-1943), a vast assortment of analogue electrical devices were soon developed for consumer use, though initially these devices were no more than electric lights and electromechanical applications based on electric motors and generators. 

Tesla, Nikola (1856-1943) Born in modern-day Croatia, the brilliant if eccentric Tesla came to the United States in 1884 to work for Thomas Edison s company and later for Edison s rival George West-inghouse (1846-1914). In 1891, Tesla became a naturalized American citizen. A physicist, mechanical and electrical engineer, and an inventor specializing in electromagnetism, he created fluorescent lighting, pioneered wireless communication, built an alternating- current induction motor, and developed the Tesla coil, variations of which have provided the basis for many modern electrical and electronic devices. 

From Chen, M. S, Alternating current overhead Line parameters, models, standard voltages, insulators, in The Electrical Engineering Handbook, 2nd ed., Dorf, R.C., Ed., CRC Press, Boca Raton, FL, 1998, p. 1323. 

W.H. Flench, Alternating Current Corrosion of Alu-mitmm, Trans. IEEE, Power Engineering Society wintermeeting. New York, Institute of Electrical and Electronics Engineos, Inc, 28 Jan to Feb 1973... 

If you leave your automobile headlights on for several hours when the engine is off, you will have a dead battery, as this calculation predicts. When an automobile engine is running, however, the engine drives an electrical alternator that provides the current required for the headlights and other needs. 

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