If your system doesn't need to be portable, this is the most obvious choice. What comes down the "pipe" is
AC and is far too high a voltage to be of immediate use to a digital system. It must be converted to a DC
voltage of significantly lower magnitude. There are plenty of solutions for doing this. You can use DC "lab"
power supplies, standard PC supplies (probably overkill for your needs), or AC adaptors. The last of these is
probably the best choice for most applications.