[sdiy] power supply decoupling capacitors

[Czech Martin]

This subject appeared every now and then on the list.
I made some experiments that showed that *slow* active
components do not neccessarliy need a cap for each.

Some people do not use any, others use caps a lot.

?

I also wonder why they use two caps go from + to gnd, and gnd to -.
Wouldn't one cap between + - be sufficent?
Wouldn't the situation be better if the pcb traces for + and -
would enclose as little area as possible (inductance)?
Some people say that connecting caps to gnd will introduce
unwanted noise in your gnd, which is a bad thing if gnd
and signal gnd is the same thing.

?


m.c.