I was just wondering how people arrive at a choice of power supply filtering
capacitors.  I'm thinking  of a regulated 5V supply, around 1A (7805).

Looking at published plans, it seems that some people routinely specify 2 x
2200.  Others just put in a single 1000.  What's a guy to do?

Also, data sheets indicate 0.33 "or larger" on the input if an appreciable
distance from the filter caps, but published plans seem to use 0.1 or 0.22.
Anyone know why?

And, on the output, 0.1 seems to be standard.  Motorola says values less than
0.1 could cause instability.  Wouldn't this tempt you to use more than 0.1?

 As I say, it's a mystery to me.  Any enlightenment on the Zen of capacitor
selection would be appreciated.

Thanks,
Colin

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.