[net.micro] phone line powered modems

lauren%lbl-csam@vortex.UUCP (06/23/83)

From:  Lauren Weinstein <vortex!lauren@lbl-csam>

Sure, you can do a lot using low power with CMOS, *if* you do it
right.  However, virtually all of these modems are not strictly
CMOS.  There are almost always conventional non-CMOS op-amps, and
of course other components as well.  Most modems will include
at least one relay (possibly a reed, but still a relay) for phone line
interfacing.  Of course, there are usually some LED's as well, plus
RS232 line drivers and the like.  All of these components add up.

In any case, regardless of theory, many persons have had poor or
at least marginal results with "powered by the phone line" modems.

--Lauren--