Martin R. Green wrote:
<snip>
> I realize they eliminate the designer's need to get safety approval for
> their hardware....
<snip>
I don't know if the rules have changed in the last few years but there
used to be a "Catch-22" in the CSA and UL (North America) rules.  These
"Wall warts" are approved only as long as they are used "stand-alone".
i.e.: powering NOTHING (strange, but true).  As soon as it's attached to
(or plugged into) something it was deemed a "new" and unapproved
device.  You had to go through approval testing with both your product
and the wall-mounted power supply and both had to pass.  If this has
changed I'm sure somebody will let me know.
--Matt