On Sun, 04 Oct 2009 12:44:44 -0700, James Sweet
wrote:



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.

78xx switch mode DC-DC.

95% efficiency is a bit optimistic for the real world. 85%, perhaps.
I still don't want to increase my power bill by even 10%, though it's
better than 10x.

Most power supplies are more or less the same thing. That said, there
is still no advantage to DC distribution and a *LOT* of
disadvantages.

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.

You still haven't identified *ONE* reason to go through this crap.