Circuits & Digital Systems
An intuitive, interactive Circuit Analysis and Digital Logic course covering the topics typical of the first two years of an electrical engineering degree. Every lesson pairs plain-language explanations with precise circuit diagrams, worked examples, hands-on simulations, and practice you can check yourself.
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Foundations of Circuit Analysis
Charge, current, voltage, and Kirchhoff's laws — the toolkit every later module builds on.
Nodal & Mesh Analysis
Systematic methods for solving any resistive network — node voltages and mesh currents.
Network Theorems
Thévenin, Norton, superposition, and maximum power transfer for linear networks.
Op-Amps & Active Circuits
Dependent sources and the ideal op-amp model, applied to real amplifier configurations.
Capacitors & Inductors
Energy-storing elements, their series/parallel combinations, and the principle of duality.
First-Order Transients
Natural and step responses of RC and RL circuits — the general first-order method.
Second-Order Transients
Natural and step responses of series and parallel RLC circuits, across all damping regimes.
AC Steady-State & Phasors
Sinusoidal analysis using phasors, impedance, and phasor-domain network methods.
AC Power Analysis
Real, reactive, and complex power, RMS values, and power factor correction.
Frequency Response & Filters
Transfer functions, Bode plots, passive filter topologies, and resonance.
Digital Logic Foundations
Number systems, Boolean algebra, logic gates, and simplification methods.
Combinational & Sequential Logic
Building blocks of digital systems, from adders to flip-flops, counters, and registers.
New lessons are added continuously. Prefer to test yourself? Try the Electrical Aptitude test.