The invention relates to a method for the data transmission from an emitter (1) to a receiver (2) in an AC voltage network, comprising a distributor (3) and at least one user group (4) with one or several users (5), wherein the emitter (1) feeds a signal to the AC voltage network by means of a power source (6).

In a system and method for operating a system, a drive is connectable to a supply-voltage source, especially an AC-voltage source, with the aid of an apparatus, in particular a control unit, via electric lines installed in the system, and information is transmittable between the control unit and the drive, using the lines.

A load control device may control power delivered from a power source, such as an alternating-current (AC) power source, to at least two electrical loads, such as a lighting load and a motor load. The load control device may include multiple load control circuit, such as a dimmer circuit and a motor drive circuit, for controlling the power delivered to the lighting load and the motor load, respectively. The load control device may adjust the rotational speed of the motor load in a manner so as to minimize acoustic noise generated by the load control device and reduce the amount of time required to adjust the rotational speed of the motor load. The load control device may remain powered when one of the electrical loads (e.g., the lighting load) has been removed (e.g., electrically disconnected or uninstalled) and/or has failed in an open state (has burnt out or blown out).

In examples, a transmission system for transmitting data and energy, with a master-module, at least one slave-module, and a two-wire line between the master-module and the slave-module for bidirectional data transmission between the master-module and the slave-module and for energy transmission from the master-module to the slave-module. Examples provide for the transmission system to be switchable be-tween several operating states, the operating states preferably differing with regard to energy transmission and/or with regard to data transmission. Furthermore, examples include an adapted master-module, a slave-module and an associated operating method.

The present application discloses an identification circuit for a power-line carrier signal. During signal transmission on a power line, the amplitude change and duration of a voltage signal on the power line are identified and then decoded into corresponding data, so as to reduce dependency on a power supply voltage during signal identification, and prevent the signal identification rate from decreasing as a result of an increase in the transmission distance, thereby reducing requirements for a system power supply.

A method for direct current power line communication in a photovoltaic system includes (a) transferring power between at least one photovoltaic device and a load using a power line, (b) maintaining a magnitude of a current flowing through the power line above a threshold value in a normal operating mode of the photovoltaic system, (c) detecting a change in operation of the power line in response to magnitude of a direct current component of the current flowing through the power line falling below the threshold value, and (d) in response to the detected change in operation of the power line, decoding operating state of the power line to obtain information.

Included are embodiments for customized load control. One embodiment of a method includes receiving altered alternating current power, where the altered alternating current power is altered via inclusion of a delay to communicate a message, converting the message in the altered alternating current power into a computer-readable format, and determining an action to take related to the message. Some embodiments include utilizing the altered alternating current power for performing the action, based on the message.

Techniques for duplex communication and power transfer across an isolator are provided. In an example, a first transceiver coupled to a firs-t side of an isolator can include a transmit modulator configured to receive first data and timing signals, to provide control signals to oscillate an output of the transceiver to transmit power and to order each half-cycle of an oscillation cycle of the output to transmit the first data. A second transceiver coupled to a second side of the isolator can include a receive detection circuit configured to compare a received oscillation cycle with a plurality of thresholds and to provide a plurality of comparator outputs indicative of reception of the positive half-cycle and the negative half-cycle, and a receive decoder configured to identify the order of half-cycles and to provide an output indicative of logic level of the first data.

Provided is a communication device using a powerline which can transmit and receive control data and so on by using the powerline, and an LED (Light Emitting Diode) lighting system using the device which can control the illumination of an LED by using the communication device. The LED illumination device comprising: one or more control devices coupled with commercial power source through powerlines; one or more LED illumination devices coupled with control devices, respectively, through the powerlines; and a management device for performing communication with the control devices; wherein the control devices and the LED illumination device perform data transmission and reception by using the powerlines, the data communication from the control devices to the LED illumination device is executed by broadcasting method, and the data communication from the LED illumination device to the control devices is executed by polling method.

A lighting system includes a light-emitting diode (LED) that emits light having a hue that varies in response to variations in a voltage applied to the LED and an intensity that varies in response to variations in a duty cycle of the applied voltage. The lighting system includes a controller configured to receive a command signal having a periodic peak voltage and a periodic valley voltage. The controller includes a peak detector and a valley detector that detects the peak voltage and the valley voltage, respectively. The controller includes a pulse generator that generates a pulse stream having a pulse-voltage magnitude substantially equal to the detected peak voltage and a pulse-voltage duty cycle substantially equal to the ratio of the detected valley voltage to the detected peak voltage. The generated pulse stream is applied to the LED resulting in light emission of the controlled hue and of the controlled intensity.