A coupling circuit for power line communications includes a coupling transformer having first and second mutually coupled windings, with the first winding connectable to a power line. The second winding includes a pair of intermediate taps with one or more tuning inductor therebetween. The inductor or inductors are set between a first portion and a second portion of the second winding of the coupling transformer. A switch member is provided coupled with the inductor. The switch member is selectively actuatable to short-circuit the inductor.

A circuit (100) for coupling an amplifier (1) in an electrical power distribution system with the amplifier electrically and physically isolated from a power line of the system. The amplifier generates arbitrary signal waveforms injected into the power line. A transformer (T1) has a primary and a secondary side with the amplifier located on the primary side and the secondary side connected to the power line. A resistor (R1) series connected with the primary side of the transformer is sized to accommodate a minimum load impedance of the amplifier and minimize power dissipation. A resonant circuit interposed between the secondary side of the transformer and the power line has values for a capacitor (C1) and an inductor (L3) forming the resonant circuit chosen to peak the amplitude of the arbitrary signal waveform at the frequency of a waveform propagated through the power line.

Methods, apparatus and computer programs for transmitting and/or receiving information are described. Information encoded in a carrier signal comprising a modulation pattern superimposed on a grid frequency at which electricity flows in a synchronous area of an electric power grid, is decoded by measuring, at a receiving device, a characteristic relating to a frequency of electricity flowing in the electric power grid, accessing data indicative of one or more predetermined code patterns and performing a correlation process to determine a correlation between the modulation pattern and one of the one or more predetermined code patterns. The information is decoded on the basis of the determined correlation. This enables information to be easily transmitted within a synchronous area of the electric power grid.

A power and data communication system includes an inboard computer, an outboard computer, and first and second wires. The first and second wires connect a first isolation transformer of the inboard computer to a second isolation transformer of the outboard computer. The inboard computer drives a driven voltage through the first isolation transformer. The outboard computer is configured to receive the driven voltage through the second isolation transformer to power the outboard computer. The outboard computer includes a load that is selectively connected across the second isolation transformer to transmit data to the inboard computer. The inboard computer receives the data through the first isolation transformer.

A power and data communication system includes an inboard computer, an outboard computer, and first and second wires. The first and second wires connect a first isolation transformer of the inboard computer to a second isolation transformer of the outboard computer. The inboard computer drives a driven voltage through the first isolation transformer. The outboard computer is configured to receive the driven voltage through the second isolation transformer to power the outboard computer. The outboard computer incudes a load that is selectively connected across the second isolation transformer to transmit data to the inboard computer. The inboard computer receives the data through the first isolation transformer.

A power line communication device including a current path provided between a first terminal and a second terminal. A coupling circuit connected between the first and second terminals includes a first circuit of a first inductor connected in parallel with a first capacitor and a first resistor. A sensor is configured to sense a communication parameter of the coupling circuit. The communication parameter may be a resonance of the first circuit, the quality (Q) factor of the resonance, the bandwidth (BW) of the coupling circuit, the resistance of the first resistor, or the impedance of the first circuit. A transceiver is adapted to couple to the first and second terminal to transmit a signal onto the current path or receive a signal from the current path responsive to the parameter of the coupling circuit and a level of current in the current path sensed by the sensor.

A system for assigning addresses to a plurality of communication nodes coupled via a power line is disclosed. Each of the plurality of communication nodes includes a current sensor. The plurality of communication nodes includes one master communication node and the master communication node is configured to start an auto-addressing process by asking the each of the plurality of communication nodes to sink a preselect amount of current and measure current, through the current sensor, flowing through the powerline under the each of the plurality of communication nodes. A first communication node in the plurality of communication nodes that does not measure any current flowing under the first communication node is assigned a first address.

A coupling circuit for power line communications includes a coupling transformer having first and second mutually coupled windings, with the first winding connectable to a power line. The second winding includes a pair of intermediate taps with one or more tuning inductor therebetween. The inductor or inductors are set between a first portion and a second portion of the second winding of the coupling transformer. A switch member is provided coupled with the inductor. The switch member is selectively actuatable to short-circuit the inductor.

Embodiments of this application provide a data transmission method applied to power line communication, and a power line communication apparatus and system. The data transmission method includes: a power line node generates a data frame, where the data frame includes a first field, a second field, and a third field, the first field is used to carry a modulation parameter, the second field is used to carry, in a bit mapping manner, identification information that is of at least one destination node of current multicast and that is configured by the power line node, and the third field is used to carry service data; and the power line node sends the data frame to a node in a power line communication network. According to the data transmission method, data can be efficiently transmitted to a plurality of destination nodes to save bandwidth.

A power line communication device including a current path provided between a first terminal and a second terminal. A coupling circuit connected between the first and second terminals includes a first circuit of a first inductor connected in parallel with a first capacitor and a first resistor. A sensor is configured to sense a communication parameter of the coupling circuit. The communication parameter may be a resonance of the first circuit, the quality (Q) factor of the resonance, the bandwidth (BW) of the coupling circuit, the resistance of the first resistor, or the impedance of the first circuit. A transceiver is adapted to couple to the first and second terminal to transmit a signal onto the current path or receive a signal from the current path responsive to the parameter of the coupling circuit and a level of current in the current path sensed by the sensor.