[sdiy] Ferrite Beads

[David G. Dixon]

> You better to because they can provide bad
> signals enter your silent mouse system!
> 
> Seriously if your system are silent as
> mouse does it really work properly? :)

It's a mouse that roars!

But in all seriousness, my system is dead silent until I hit a key or
otherwise intentionally make sound come out of it.  To be honest, I'm not
even sure how I've managed to achieve this.  I put one 10uF electrolytic and
one 100nF ceramic on each rail just past the power header, and occasionally
add another 100nF somewhere, particularly if there is anything digital on
the board.  Board-mounted regulators are separately decoupled, of course.
My panels are grounded at a single point (typically to one of the jack
rings) taken from the PCB.  Modules are all connected separately to the
power supply ground in a "star ground" configuration, but this is defeated
as soon as anything is plugged into anything else, because then the two
panels are connected through the cable shielding, so I must have ground
loops all over the place.  Doesn't matter!  I also mount all of my boards on
grounded metallic stooge brackets which cover the entire copper side of the
board, so this might provide some extra noise insulation.  Otherwise, it's
just dumb luck.