The basics of how transformers work, where to shop for step down mains transformers, and how to wire one up to mains voltages. European and North American wiring is discussed. DO NOT FORGET TO ADD A FUSE. Finally, a quick example of AC to DC conversion in an unregulated dual rail power supply. Watch the followup video on diodes and AC to DC conversion here: Example transformer: Check out my website for more videos about electronics!