A device for communicating and providing power over a cable having at least two conductors comprises a first inductor having a primary and a secondary winding, a second inductor having a primary and a secondary winding, the primary winding of the second inductor being coupled at one end to the primary winding of the first inductor, each of the secondary windings of the first and second inductors being coupled to one of the at least two conductors in the cable. The device further includes a transceiver coupled to the primary windings of the first and second inductors, wherein the first inductor is coupled to local ground potential, in a manner that varies the potential of each of the said conductors symmetrically from an average potential.