Method of, and apparatus for, inserting carrier frequency signal information onto distribution transformer primary winding

摘要

Power line carrier frequency signals are provided at a distribution transformer primary winding by controlled current injection onto the neutral and phase conductors of the distribution transformer secondary winding circuit, with the direction of current flow in each half of the secondary winding being controlled in in-phase additive fashion. Apparatus for causing in-phase distribution secondary winding current flow includes a pair of electronic current control means supplying in-phase currents to a pair of secondary windings of an auxiliary transformer having its primary winding coupled to half of the distribution transformer secondary winding and having the auxiliary transformer secondary winding center tap coupled to local neutral through a band-stop filter and to the remaining distribution transformer secondary winding through a band-pass filter for augmentation of signal current flow into the distribution transformer.