Lecture

Impedance and Kirchhoff Laws

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

In course

EE-105: Electrical engineering science and technology (Spring)

Ce cours propose une introduction à l'électrotechnique. Les lois fondamentales de l'électricité et différents composants d'un circuit électrique linéaire seront étudiés. L'analyse élémentaire des circuits en régime continu et sinusoidal sera aussi couverte ...

Description

This lecture covers the concept of impedance in sinusoidal regime, which is the quotient of voltage by current at a given frequency in steady state. It also explains the laws of Kirchhoff for circuits containing linear resistive, inductive, and capacitive elements, and how impedance allows the generalization of Ohm's law. The instructor discusses the notion of dipole, the overlay of multiple generators using voltage and current dividers, and how to handle sources with different frequencies in groups.

Instructors (4)

Roberto Zoia

Sandro Carrara

Sandro Carrara is an IEEE Fellow for his outstanding record of accomplishments in the field of design of nanoscale biological CMOS sensors. He is also the recipient of the IEEE Sensors Council Technical Achievement Award in 2016 for his leadership in the emerging area of co-design in Bio/Nano/CMOS interfaces. He is a Professor of the EPFL in Lausanne (Switzerland), and head of the "Bio/CMOS Interfaces" (BCI) research group. He is former professor of optical and electrical biosensors at the Department of Electrical Engineering and Biophysics (DIBE) of the University of Genoa (Italy) and former professor of nanobiotechnology at the University of Bologna (Italy). He holds a PhD in Biochemistry & Biophysics from University of Padua (Italy), a Master degree in Physics from University of Genoa (Italy), and a diploma in Electronics from National Institute of Technology in Albenga (Italy). His scientific interests are on electrical phenomena of nano-bio-structured films, and include CMOS design of biochips based on proteins and DNA. Along his carrier, he published 7 books, one as author with Springer on Bio/CMOS interfaces and, more recently, a Handbook of Bioelectronics with Cambridge University Press. He has more than 250 scientific publications and is author of 13 patents. He is now Editor-in-Chief of the IEEE Sensors Journal, the largest journal among 2019 IEEE publications; he is also founder and Editor-in-Chief of the journal BioNanoScience by Springer, and Associate Editor of IEEE Transactions on Biomedical Circuits and Systems. He is a member of the IEEE Sensors Council and his Executive Committee. He was a member of the Board of Governors (BoG) of the IEEE Circuits And Systems Society (CASS). He has been appointed as IEEE Sensors Council Distinguished Lecturer for the years 2017-2019, and CASS Distinguished Lecturer for the years 2013-2014. His work received several international recognitions: several Top-25 Hottest-Articles (2004, 2005, 2008, 2009, and two times in 2012) published in highly ranked international journals such as Biosensors and Bioelectronics, Sensors and Actuators B, IEEE Sensors journal, and Thin Solid Films; a NATO Advanced Research Award in 1996 for the original contribution to the physics of single-electron conductivity in nano-particles; six Best Paper Awards at the IEEE Sensors Conference 2019 (Montreal) in 2019, Conferences IEEE NGCAS in 2017 (Genoa), MOBIHEALTH in 2016 (Milan), IEEE PRIME in 2015 (Glasgow), in 2010 (Berlin), and in 2009 (Cork); three Best Poster Awards at the EMBEC Conference in 2017 (Tampere, Finland), Nanotera workshop in 2011 (Bern), and NanoEurope Symposium in 2009 (Rapperswil). He also received the Best Referees Award from the journal Biosensor and Bioelectronics in 2006. From 1997 to 2000, he was a member of an international committee at the ELETTRA Synchrotron in Trieste. From 2000 to 2003, he was scientific leader of a National Research Program (PNR) in the filed of Nanobiotechnology. He was an internationally esteemed expert of the evaluation panel of the Academy of Finland in a research program for the years 2010-2013. He has been the General Chairman of the Conference IEEE BioCAS 2014, the premier worldwide international conference in the area of circuits and systems for biomedical applications

Official source

Ontological neighbourhood

Physics

Electromagnetism: Electrical networks

Related concepts (32)

Voltage divider

In electronics, a voltage divider (also known as a potential divider) is a passive linear circuit that produces an output voltage (Vout) that is a fraction of its input voltage (Vin). Voltage division is the result of distributing the input voltage among the components of the divider. A simple example of a voltage divider is two resistors connected in series, with the input voltage applied across the resistor pair and the output voltage emerging from the connection between them.

Kirchhoff's circuit laws

Kirchhoff's circuit laws are two equalities that deal with the current and potential difference (commonly known as voltage) in the lumped element model of electrical circuits. They were first described in 1845 by German physicist Gustav Kirchhoff. This generalized the work of Georg Ohm and preceded the work of James Clerk Maxwell. Widely used in electrical engineering, they are also called Kirchhoff's rules or simply Kirchhoff's laws. These laws can be applied in time and frequency domains and form the basis for network analysis.

Linear span

In mathematics, the linear span (also called the linear hull or just span) of a set S of vectors (from a vector space), denoted span(S), is defined as the set of all linear combinations of the vectors in S. For example, two linearly independent vectors span a plane. The linear span can be characterized either as the intersection of all linear subspaces that contain S, or as the smallest subspace containing S. The linear span of a set of vectors is therefore a vector space itself. Spans can be generalized to matroids and modules.

Linear algebra

Linear algebra is the branch of mathematics concerning linear equations such as: linear maps such as: and their representations in vector spaces and through matrices. Linear algebra is central to almost all areas of mathematics. For instance, linear algebra is fundamental in modern presentations of geometry, including for defining basic objects such as lines, planes and rotations. Also, functional analysis, a branch of mathematical analysis, may be viewed as the application of linear algebra to spaces of functions.

Electrical reactance

In electrical circuits, reactance is the opposition presented to alternating current by inductance and capacitance. Along with resistance, it is one of two elements of impedance; however, while both elements involve transfer of electrical energy, no dissipation of electrical energy as heat occurs in reactance; instead, the reactance stores energy until a quarter-cycle later when the energy is returned to the circuit. Greater reactance gives smaller current for the same applied voltage.

Related lectures (64)

Analog Structures: Summary of Operational Amplifiers MOOC: Electronics II

Covers the summary of operational amplifiers, transconductance amplifiers, and analog structure models.

Impedances and Impedance Networks MOOC: Electrical engineering I

Covers the representation of impedances, voltage and current dividers, and impedance networks in electrical engineering.

Basic Concepts: Electric Circuits

Introduces the fundamental concepts of electric circuits, including basic elements and Kirchhoff's laws.

AC Circuits: Complex Impedance Analysis

Covers the analysis of AC circuits, focusing on complex impedance and phase differences between current and voltage.

Laws of Kirchhoff: Reminder and Examples