Abstract: A method and system are given for a coupling a data signal over a power distribution system. An inductive signal coupler has two windings. The first winding is in series with a line conductor of the power distribution system. A capacitor is connected between the first line conductor and a second line conductor of the distribution system such that the capacitor presents a high impedance to a power signal and a low impedance to a data signal. A communication device is connected to the second winding so that a data signal can be coupled between the communication device and the distribution system.

Abstract: There is provided a method for protecting loads associated with power distribution system inductive signal couplers. The method includes (a) providing an inductive signal coupler having a first winding in series with a line conductor of a power distribution system, and a second winding having first and second connection terminals, (b) connecting a first terminal of a first fuse to the first connection terminal, and a first terminal of a second fuse to the second connection terminal, a second terminal of each fuse being connected to a communication device, and (c) connecting a first terminal of a first choke to the second terminal of the first fuse, and a first terminal of a second choke to the second of the second fuse, a second terminal of each choke being connected to an electrical ground.

Abstract: There is provided a method for identifying one of a plurality of neutral wires of a power transmission cable. The method comprises (a) applying a signal to a selected neutral wire, at a first point on the power transmission cable, (b) sensing a relative magnitude of the signal on each of the plurality of neutral wires at a second point on the power transmission cable that is remote from the first point, and (c) identifying the selected neutral wire from the relative magnitudes. There is also provided a system for identifying one of a plurality of neutral wires of a power transmission cable.

Abstract: There is provided an inductive power line data coupler. The coupler includes (a) a magnetic core having a high magnetic permeability at a data communication frequency and being configured to allow a power line of a power distribution system to be routed through the magnetic core to serve as a primary winding, (b) a data signaling circuit that provides a secondary winding through the magnetic core for coupling a data signal between the power line and a communication device, and (c) a choke coil coupled to the data signaling circuit for creating a flux-canceling power frequency current opposite in direction and comparable in magnitude to a power frequency current. The coupler may also include a circuit for sensing a level of current in the power line.

Abstract: There is provided a coupling circuit for a full duplex modem having a transmitter and a receiver. The coupling circuit includes (a) a first transformer having a primary winding and a secondary winding, where the primary winding is coupled to the transmitter, (b) a second transformer having a primary winding and a secondary winding, where the primary winding of the second transformer is coupled to a communications line, and (c) a resistance between a terminal of the primary winding of the first transformer and a terminal of the primary winding of the second transformer. The secondary windings of the first and second transformers are connected in series, with opposing phase, and coupled to the receiver to minimize a level of a signal from the transmitter from reaching the receiver.

Abstract: There is provided an apparatus for enabling communication of a data signal via a power transmission cable. The apparatus includes (a) a first winding for coupling the data signal via a conductor of the power transmission cable, and (b) a second winding, inductively coupled to the first winding, for coupling the data signal via a data port. The apparatus further includes the power transmission cable having a first neutral conductor and a second neutral conductor and apparatus for differential coupling of the data signal to the first and second neutral conductors.

Abstract: There is provided an apparatus for enabling communication of a data signal via a power transmission cable. The apparatus comprises (a) a first winding for coupling the data signal via a conductor of the power transmission cable, and (b) a second winding, inductively coupled to the first winding, for coupling the data signal via a data port.

Abstract: There is provided an apparatus for enabling communication of a data signal via a power transmission cable. The apparatus comprises (a) a first winding for coupling the data signal via a conductor of the power transmission cable, and (b) a second winding, inductively coupled to the first winding, for coupling the data signal via a data port.

Abstract: A power and data transfer system includes a portable device with a first contact circuit formed from a pair of contact pads having an outer surface covered with a dielectric material. A processing unit is coupled to the first contact circuit. A host unit has a second contact circuit including a second pair of contact pads which are also covered with a dielectric material. A host processing unit is coupled to the second contact circuit. The first and second contact circuits are adapted to form a capacitive interface when the portable device is positioned proximate the host unit. The capacitive interface transmits power signals from the host unit to the portable device. The same contacts are used to transmit bi-directional data signals between the portable device and the host unit.