| Free Resource | Best for | Link (search via your preferred engine) | |---|---|---| | Lessons in Electric Circuits (Kuphaldt) | DC/AC, semiconductors, op-amps | AllAboutCircuits.com | | Introduction to Electronics (Erik Cheever) | BJT/FET biasing | Swarthmore OER | | Analog Circuits (Prof. Tony Chan Carusone, MIT) | Graduate-level Millman replacement | MIT OpenCourseWare | | Electronics for Physicists (Bryan H. Suits) | Italian physics students | Springer (free via many uni subscriptions) |