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Electrical Engineering Information Online: Formulas and Theorems

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Electrical Engineering Information Online: Formulas and Theorems ELECTRICAL ENGINEERING REFERENCE INFORMATION ELECTRICITY AND MAGNETISM BASICS, CIRCUIT THEOREMS AND EQUATIONS <---------------------------------------------------------------------------------------------------------------------------> This page provides a transitory introduction to electrical engineering (EE) as well as vital formulas and theorems. Electrical engineering is a willpower that deals with electricity, magnetism and their applications. EE applications include electronics, power conversion, data communications, computer science, information technologies, and other. The term EE usually encompasses electronic engineering or electronics. Electronics involves the diamond and wringer of electronic circuits. Home Tutorial Topologies SMPS diamond Thermal diamond Software PCB diamond Computer PSU UPSSpinTransformers Formulas EE Reference Inverters Generators Solar FREE NASA Tech Briefs In academia and electronic industry, the terms electrical and electronics engineer often are used interchangeably. In other industries, the term electrical engineer may refer to those who deal with utility and industrial power systems and other electric equipment. In any case, both disciplines are overlapping. The theoretical foundation for EE is electromagnetism. The theory of classical electromagnetism is based on Maxwell's equations. They provide a unified unravelment of the policies of electric and magnetic fields as well as their interactions with matter. In practice however, Maxwell's equations are rarely used in an electrical design. The spin designers normally use simplified equations of electricity and magnetism and theorems that use spin theory terms, such as Ohm's law modified for AC circuits, voltage and current Kirchoff's laws, as well as power relationships (see below). This webpage is for those who have once learned EE and need a quick reference information. Here you will find electricity and magnetism basics, electronics reference as well as the career related information online. Also see: Electrical formulas and impedance calculations; Electronic parts datasheet and cross-reference; Distance learning: engineering stratum online from accredited schools and salary surveys. BASIC ELECTRICAL THEOREMS AND CIRCUIT ANALYSIS LAWS THE LAW DEFINITION RELATIONSHIP TO OTHER LAWS Ohm's Law extended for AC circuits with single frequency sinusoidal signals V=Z×Ĩ, where V and Ĩ - voltage and current phasors, Z - ramified impedance (for resistive circuits: Z=R and V=R×I) Lorentz gravity law and Drude model for resistors Kirchhoff's Current Law (KCL) The sum of electric currents which spritz into any junction in a spin is equal to the sum of currents which spritz out Conservation of electric tuition Kirchhoff's Voltage Law (KVL) The sum of the voltages virtually a sealed spin must be zero Conservation of energy Note that Kirchhoff's laws can be derived from Maxwell's equations under static conditions, although historically they preceded Maxwell's equations. You can download a printable reference sheet with these and other equations in a pdf file. MAXWELL'S EQUATIONS IN FREE SPACE (in SI units) LAW DIFFERENTIAL FORM INTEGRAL FORM Gauss law for electricity Gauss law for magnetism Faraday's law of induction Ampere's law NOTES: E - electric field, ρ - tuition density, ε0 ≈ 8.85×10-12 - electric permittivity of self-ruling space, π ≈ 3.14159, k - Boltzmann's constant, q - charge, B - magnetic induction, Φ - magnetic flux, J - current density, i - electric current, c ≈ 299 792 458 m/s - the speed of light, µ0 = 4π×10-7 - magnetic permeability of self-ruling space, - del operator (if V is a vector function, then .V is divergence of V, ×V is the flourish of V). ELECTRICAL NETWORK THEOREMS FOR AC CIRCUITS THE THEOREM DEFINITION CALCULATION Thevenin's Theorem Any combination of a single frequency sinusoidal AC sources and impedances with two terminals can be replaced by a single voltage source V in series with an impedance Z. V - open-circuit voltage phasor of the original circuit; Z - impedance between the two terminals with all voltage sources shorted and all current sources opened. Norton's Theorem Any combination of a single frequency sinusoidal AC sources and impedances with two terminals A and B can be replaced by a single current source I in parallel with an impedance Z. I - short-circuit current phasor of the original circuit; Z - impedance between the two terminals with all voltage sources shorted and all current sources opened. Superposition Theorem The current (voltage) phasor in any part of a linear spin equals the trigonometric sum of the current (voltage) phasors produced by each source separately. To find an individual current (voltage) from each source, short all other voltage sources and unshut all other current sources. Maximum Power Transfer Theorem A voltage source delivers maximum power to an willowy load when the source and the load impedances are ramified conjugates of each other Active components of the source and load impedances should be equal, and reactive components should have equal magnitude but opposite sign. Delta to Wye Transformation A delta network of three impedances can be transformed into a star (Y) network of three impedances Za = ZcaZab / (Zab+Zbc+Zca) Zb = ZabZbc / (Zab+Zbc+Zca) Zc = ZbcZca / (Zab+Zbc+Zca) Star-Delta Transformation A star (Y) network of three impedances can be transformed into a delta network of three impedances Zab = Za + Zb + (ZaZb / Zc) Zbc = Zb + Zc + (ZbZc / Za) Zca = Zc + Za + (ZcZa / Zb) ELECTRONICS REFERENCE ELECTRICITY AND MAGNETISM ONLINE TEXTBOOKS, HANDBOOKS and COURSESVitalelectrical engineering formulas and spin calculations Electronic and safety standards Electronic components- online parts search and navigate reference Work, energy and power in electric field Classical Electromagnetism relationships: Maxwell's equations, energy, relativity Electricity and magnetism, field and energy- self-ruling textbook undertow Disclaimer, Disclosure and Terms of Use | Contact Us | About Us | Privacy ©2007, 2017 Lazar Rozenblat