One set of laws for every circuit, built one chapter at a time
This is a living, web-native edition of a classic course in Electric Circuits and Networks. Each of the 19 chapters lives on its own page — readable on any device, searchable, and free to share. The journey starts with the simple question of what charge and current are, and ends with the two-port descriptions that let an entire network be replaced by four numbers.
The sequence follows the standard electrical engineering curriculum, building from Ohm's and Kirchhoff's laws through the systematic methods of nodal and mesh analysis and the theorems that simplify any network, then on to the energy-storage elements whose differential equations produce transients, the phasor algebra that makes the sinusoidal steady state as easy as a DC problem, and finally the Laplace, Fourier and two-port methods that carry circuit analysis into modern engineering practice. Pick any chapter below to begin, or follow the three parts in order for a complete course.
DC Circuits
Basic Concepts & Laws · Nodal & Mesh Analysis · Circuit Theorems · Operational Amplifiers · Capacitors & Inductors · First- and Second-Order Transients
AC Circuits
Sinusoids & Phasors · Impedance · Sinusoidal Steady State · AC Power · Three-Phase Systems · Magnetic Coupling · Frequency Response & Resonance
Advanced Circuit Analysis
The Laplace Transform · Transfer Functions & State Variables · Fourier Series · The Fourier Transform · Two-Port Parameters
Before any theorem or transform, there is a question: what exactly is flowing, what pushes it, and what bookkeeping keeps the accounts honest? The first chapter sets the scene — charge and current, voltage and power, the passive sign convention that decides every minus sign in the book, and the idea of a circuit element as a model rather than a thing. Get the conventions right here and the remaining eighteen chapters are arithmetic. Open Chapter 1 →