I had a really good experience in this area with the MITx (now Edx) Circuits and Electronics Course. (This is an introductory course.) The final question of th

I had a really good experience in this area with the MITx (now Edx) Circuits and Electronics Course. (This is an introductory course.) The final question of their end of course exam involves reading a real schematic for a real product and answering questions about it (I won't say what product, because they are still running the course). Quite tricky and very satisfying to work out. Other reasons I enjoyed the course: excellent virtual lab tools, and side lectures from Gerald Sussman.