Lecture

Thevenin and Norton Theorems

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In course

EE-100: Electrical engineering science & technology

Ce cours propose une introduction aux sciences et technologies de l'électricité en mettant l'accent sur les composants des circuits électriques. L'enseignement comprend à la fois une partie théorique avec un cours et des exercices, ainsi qu'une partie expé ...

Description

This lecture introduces the Thevenin and Norton theorems, which allow transforming complex circuits into equivalent voltage and current sources, respectively. The instructor demonstrates how to apply these theorems to calculate the equivalent circuits, emphasizing the relationship between current, voltage, and internal resistance. Through examples, the lecture shows how to determine the equivalent source values and internal resistances for both types of circuits. The equivalence between the Thevenin and Norton circuits is highlighted, leading to a practical exercise involving solving circuits using superposition, Thevenin's theorem, and Norton's theorem to ensure a correct solution.

Instructors (4)

Philippe Allenbach

Adil Koukab

Olivier Martin

Olivier J.F. Martin received the M.Sc. and Ph.D. degrees in physics in 1989 and 1994, respectively, from the Swiss Federal Institute of Technology, Lausanne (EPFL), Switzerland. In 1989, he joined IBM Zurich Research Laboratory, where he investigated thermal and optical properties of semiconductor laser diodes. Between 1994 and 1997 he was a research staff member at the Swiss Federal Institute of Technology, Zurich (ETHZ). In 1997 he received a Lecturer fellowship from the Swiss National Science Foundation (SNSF). During the period 1996-1999, he spent a year and a half in the U.S.A., as invited scientist at the University of California in San Diego (UCSD). In 2001 he received a Professorship grant from the SNSF and became Professor of Nano-Optics at the ETHZ. In 2003, he was appointed Professor of Nanophotonics and Optical Signal Processing at the Swiss Federal Institute of Technology, Lausanne (EPFL), where he is currently head of the Nanophotonics and Metrology Laboratory and Director of the Microengineering Section.

Roberto Zoia

Official source

Ontological neighbourhood

Physics

Electromagnetism: Electrical networks

Related concepts (26)

Thévenin's theorem

As originally stated in terms of direct-current resistive circuits only, Thévenin's theorem states that "Any linear electrical network containing only voltage sources, current sources and resistances can be replaced at terminals A–B by an equivalent combination of a voltage source Vth in a series connection with a resistance Rth." The equivalent voltage Vth is the voltage obtained at terminals A–B of the network with terminals A–B open circuited.

Norton's theorem

In direct-current circuit theory, Norton's theorem, also called the Mayer–Norton theorem, is a simplification that can be applied to networks made of linear time-invariant resistances, voltage sources, and current sources. At a pair of terminals of the network, it can be replaced by a current source and a single resistor in parallel. For alternating current (AC) systems the theorem can be applied to reactive impedances as well as resistances. The Norton equivalent circuit is used to represent any network of linear sources and impedances at a given frequency.

Voltage source

A voltage source is a two-terminal device which can maintain a fixed voltage. An ideal voltage source can maintain the fixed voltage independent of the load resistance or the output current. However, a real-world voltage source cannot supply unlimited current. A voltage source is the dual of a current source. Real-world sources of electrical energy, such as batteries and generators, can be modeled for analysis purposes as a combination of an ideal voltage source and additional combinations of impedance elements.

Equivalent circuit

In electrical engineering, an equivalent circuit refers to a theoretical circuit that retains all of the electrical characteristics of a given circuit. Often, an equivalent circuit is sought that simplifies calculation, and more broadly, that is a simplest form of a more complex circuit in order to aid analysis. In its most common form, an equivalent circuit is made up of linear, passive elements. However, more complex equivalent circuits are used that approximate the nonlinear behavior of the original circuit as well.

Network analysis (electrical circuits)

In electrical engineering and electronics, a network is a collection of interconnected components. Network analysis is the process of finding the voltages across, and the currents through, all network components. There are many techniques for calculating these values; however, for the most part, the techniques assume linear components. Except where stated, the methods described in this article are applicable only to linear network analysis.

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