A system for providing DC power on local telephone lines, such as
telephone lines in a building or office, for powering devices and
circuitry associated with communications over those telephone lines, as
well as other functions. Desired voltage and power levels are supplied
over local telephone lines by separating the DC power component from the
central office or private branch exchange with a DC blocking filter while
passing all AC telephony signals. A distinct DC power is then imposed
over the telephone line for powering both the telephony service as well
as other loads. Conventional telephone off-hook detection is simulated
for compatibility with the central office or private branch exchange. The
functions required may be integrated, partially or fully within a
telephone outlet.