Edwin wrote:
[...]
>      (2) If I have A/C anyway, is there a inexpensive way (i.e. less than
>      the cost of a AC/DC adapter) to convert A/C to a DC in the PIC
>      operating voltage?
>
>      -Edwin

You could do it with a resistive voltage divider, diode, and capacitor
to form a half-wave rectifier which would feed a voltage regulator.  The
single power resistor you would need (it'd have to be able to handle at
least 2 or 3 Watts) may be expensive, but it would eliminate the need
for a transformer.

[The design of such a supply is left as an excercise for the reader.  :-]

Overall I don't know if it would turn out to be cheaper than an average
wall adapter but it should be smaller and certainly lighter.

Hmmm...  Now I'm thinking of all the uses *I* might have for such an
adapter.  As if I don't already have enough to do...

Rick Miller