Remember, it's just a discussion
about possibilities. Good grief, 78xx regulators are very
inexpensive and DC-DC controllers are getting that way too.

They're *very* wasteful too. I don't want my power bills to go up 7x.



In all fairness, DC-DC converters can exceed 95% efficiency, and 85% is
common. They're really not too bad.

The class II transformers used to power most small stuff are down around
50%. It's one reason switchmode power supplies have become popular for
those applications. A SMPS is nothing but a DC-DC converter that first
rectifies the AC line to DC.