ELECTRICAL ENCYCLOPEDIA

Henry (unit) http://en.wikipedia.org/wiki/Henry_(unit)   In physics, and electronics, the Henry (symbol H) is the SI unit of inductance. It is named after Joseph Henry (1797–1878), the American scientist who discovered electromagnetic induction independently of and at about the same time as Michael Faraday (1791–1867) in England. The magnetic permeability of the vacuum is 4π×10−7 H/m (henry per meter). Joseph Henry http://www.aip.org   Well into the nineteenth century American science existed, where it existed at all, either as a genteel pastime or as an adjunct to the urgent needs of the new nation—agriculture, navigation, exploration. The best research was usually done in fields serving these practical interests, and the closest approach to physics was work in positional astronomy, meteorology, geology and the like. Joseph Henry arose from this tradition and quickly surpassed it. Henry Conversion http://online.unitconverterpro.com   Online Unit Converter. Various henry conversion f

Fundamentals for all Capacitor http://www.sofia.usra.edu   For all practical purposes, consider only the parallel-plate capacitor: two conductors or electrodes separated by a dielectric material of uniform thickness.  The conductors can be any material which will conduct electricity easily. The dielectric material must be a poor conductor – an insulator. History of Capacitor http://www.hkcapacitor.com   In October 1745, Ewald Georg von Kleist of Pomerania in Germany found that charge could be stored by connecting a generator by a wire to a volume of water in a hand-held glass jar. Von Kleist's hand and the water acted as conductors and the jar as a dielectric. Von Kleist found that after removing the generator, touching the wire resulted in a spark. In a letter describing the experiment, he said "I would not take a second shock for the kingdom of France." The following year, the Dutch physicist Pieter van Musschenbroek invented a similar capacitor, which was named the L

Norton's Theorem http://en.wikipedia.org   Norton's theorem for linear electrical networks, known in Europe as the Mayer–Norton theorem, states that any collection of voltage sources, current sources, and resistors with two terminals is electrically equivalent to an ideal current source, I, in parallel with a single resistor, R. For single-frequency AC systems the theorem can also be applied to general impedances, not just resistors. The Norton equivalent is used to represent any network of linear sources and impedances, at a given frequency. The circuit consists of an ideal current source in parallel with an ideal impedance (or resistor for non-reactive circuits). Edward Lawry Norton www.facebook.com/pages   Edward Lawry Norton (28 July 1898, Rockland, Maine–28 January 1983, Chatham, New Jersey) was an accomplished Bell Labs engineer and scientist famous for developing the concept of the Norton equivalent circuit. He attended the University of Maine for two years before tra

Origin of Equivalent Circuit Theorem http://www.ece.rice.edu/~dhj/paper1.pdf   The theoretical foundations of linear circuit theory rest on Maxwell’s theory of electromagnetism. In its more applied form, circuit theory rests on the key concepts of Kirchoff’s Laws, impedance, Ohm’s Law (in its most general sense by encompassing impedances), and the Principle of Superposition. From this foundation, any linear circuit can be solved: Given a specification of all sources in the circuit, a set of linear equations can be found and solved to yield any voltage and current in the circuit. One of the most surprising concepts to arise from linear circuit theory is the equivalent circuit:  Thevenin Theorem http://www.scribd.com/   Thevenin’s theorem permits the reduction of a two-terminal dc network with any number of resistors and sources (Complex Circuit) to one Equivalent circuit having only one source and one internal resistance in a series configuration shown below Thevenin Theorem in Circui