You can take the MIT sequence of courses on edX (taught by, I believe the CEO of edX, so, in a sense, this is the original flagship edX course) https://www.edx.org/course/circuits-electronics-1-basic-circ... https://www.edx.org/course/circuits-electronics-2-amplificat... https://www.edx.org/course/circuits-electronics-3-applicatio...