Abstract: A power supply system for a lighting unit, comprises a driver, a local energy storage device and a converter. The converter implements a first, charging mode, mode by connecting to the output of said driver for diverting at least a part of the driving current from the lighting unit to charge the energy storage device, a second, battery driving, mode by connecting to the lighting unit for converting the local energy storage device power supply to drive the lighting unit, and a third, grid driving, mode to neither charge the energy storage device nor convert the secondary power supply. The converter and the driver are controlled actively and synchronously to maintain the current through the lighting unit when switching the converter between modes.

Abstract: A lighting network for altering a power factor of an alternating current, AC, supply (5). The lighting network comprises luminaires (2, 3) having reactive components of a first reactive type which are controllably coupled, by a controller, to the AC supply so as to adjust the power factor of the AC supply. The controller controls the coupling of the luminaires based on a power factor signal indicative of a power factor of the AC supply, which is influenced by an appliance (6) with a reactive load of a second reactive type, which appliance is different to any one of the luminaires. Preferably, the first reactive type is capacitive, and the second reactive type is inductive.

Abstract: A power supply system for a lighting unit, comprises a driver, a local energy storage device and a converter. The converter implements a first, charging mode, mode by connecting to the output of said driver for diverting at least a part of the driving current from the lighting unit to charge the energy storage device, a second, battery driving, mode by connecting to the lighting unit for converting the local energy storage device power supply to drive the lighting unit, and a third, grid driving, mode to neither charge the energy storage device nor convert the secondary power supply. The converter and the driver are controlled actively and synchronously to maintain the current through the lighting unit when switching the converter between modes.

Abstract: A driving circuit for driving an appliance has a two-line power input, a first output for connection to the appliance, a second, two-line, output, an internal energy source and a switching arrangement. The switching arrangement is configurable into at least a first mode, in which the two-line power input is connected to the second, two-line, output, and the internal energy source is isolated from direct connection to the two-line power input, and a second mode in which the internal energy source is in series between a first line of the two-line power input and a corresponding first line of the second, two-line, output. The first mode is used for normal operation of an appliance and the second mode is used for grid feeding.

Abstract: Methods and devices are disclosed for a reusable PaYG dongle (10) including a data connection (11) arranged to connect to one or more PaYG products (20) and transfer data (17) to the one or more PaYG product (20) and an input unit arranged to receive an external signal (18). A controller (12) is arranged to process the external signal (18) and transfer the enable signal (17) using the data connection (11) to the one or more PaYG products (20) based upon the external signal (18). The methods are for enabling the one or more PaYG products (20) using the reusable PaYG dongle (10).

Abstract: A battery charger, or charge controller, for a photovoltaic system is disclosed, comprising a maximum power point tracker (MPPT) circuit, which may be bypassed by means of a bypass circuit. The bypass circuit may be a simple electrical wire or link. The battery charger is operable to track the maximum power of a photogenerator by means of the MPPT, or to bypass the MPPT and disable it, in dependence on whether the power loss which results from the MPPT would be greater than the power saving achieved by tracking the maximum power point of the photogenerator. Also disclosed is a control unit for use in such a battery charger, and a method for controlling such a battery charger.

Abstract: A battery charger, or charge controller, for a photovoltaic system is disclosed, comprising a maximum power point tracker (MPPT) circuit, which may be bypassed by means of a bypass circuit. The bypass circuit may be a simple electrical wire or link. The battery charger is operable to track the maximum power of a photogenerator by means of the MPPT, or to bypass the MPPT and disable it, in dependence on whether the power loss which results from the MPPT would be greater than the power saving achieved by tracking the maximum power point of the photogenerator. Also disclosed is a control unit for use in such a battery charger, and a method for controlling such a battery charger.