[sdiy] filter cap needed?

[David G. Dixon]

> > However, something has been troubling me about these caps: If several of
> > them are connected between a rail and ground at various locations,
> wouldn't
> > they end up fulfilling the same function as one cap, several times as
> large
> > (given that they are capacitances in parallel)?
> >
> If they are at different locations, there must be a conductor between
> them which has resistance and inductance.
> So, for high frequencies, no they wouldn't .

What do you mean by "high"?  Assuming the trace represents a resistor R = 1
ohm (which is probably conservative), and the cap is C = 0.1uF, then this
makes a low-pass filter with a cutoff frequency of about 1.6 MHz.  How does
this help?