Come on.   If your going to do that just redesign the whole thing.  Bottom
    line is the cheap ones get warm or hot.   You get what you pay for.

It's not "cheap" that is at issue, it's the fact that te regulator is
linear.  You can substitute an arbitrarilly expensive low-dropout,
high-precision, low-noise, low-ripple, micropower, remote-sensing,
remote-shutdown linear regulator and it will get just as hot.  This is
PHYSICS.  You can't get around it; if you use a linear regulator, the
"extra" voltage HAS to get dissipated as heat.  The implication that there
might be a more expensive linear regulator you could put on the same PCB is
misleading.  (OTOH, there ARE 3-terminal switching regulators designed to
drop into 7805 footprints, and they're certainly NOT cheap.)


    My sugeston is to drop the input voltage if you can.

This is fine advice.  Note that using dropping resistors you will STILL have
the same overall power dissipation, but some of that will be moved to the
dropping resistor instead of the regulator.  This is swell if you're only
worried about the regulator, and useless if overall heating is an issue.

BillW

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