gEDA-user: Alarm clocks and switching regulators

[DJ Delorie]

> But after I wrote that, I realized that I'm also driving a
> low-current 5V linear regulator off the same bulk caps, and it
> probably won't like huge ripple.

You could chain a +9 regulator between them, so that the +5 regulator
only sees the ripple out of the +9.

> It's all black magic to me.  I just remember that if you put moats in
> your ground plane, you're not supposed to let any traces cross the
> moat.)

What I read was that you do NOT want a ground plane under your
switcher, as it would couple all that switching noise into the ground
plane.  I introduced the power planes at the final filter capacitor.