Hi,

Does anyone have any hints or tips on powering a PIC from a phone
line (yes I know, one would have to get type aproval to sell them).

Does one just use the same sort of diode chain clamp that is found in
IC telephone circuits.

I seem to recall someone asked about a similar problem but am not sure
if it was to do with phone lines.

Some of the applications I have in mind are dialtone checker, ring-counter
and perhaps even a call metering device.  Power is available in
large quantities when off hook (10 V at 50-60mA) but for the ring
counter I would like to load the line as little as possible, Is there
a 10-48V to 5V switching converter IC from maxim or the like that is
used.

Cheers Kalle
--
Kalle Pihlajasaari     kalle@data.co.za
Interface Products     Box 15775, Doornfontein, 2028, South Africa
+27 (11) 402-7750      Fax: +27 (11) 402-7751