Abstract: Low cost and low power LED lamps exhibit current harmonic contents due to their nonlinear characteristics. A large scale lighting network requires tens to hundreds LED lamp installations, the resultant harmonic currents pollute the grid seriously. Furthermore, light intensity fluctuations are becoming a concern nowadays to many users, as a safety and a health problems. This phenomenon is mainly caused by heavy loads as they lead to voltage fluctuations and deteriorating in PQ and hence visual flickering in LED lamps. A single phase transformer-less unified power quality conditioner (UPQC) topology is provided with its controls to mitigate all PQ problems in a network.

Abstract: An apparatus that can operate with electronic ballasts (10) for electric discharge lamps to drive dc-powered lighting equipment (26) is provided. The apparatus is directly connected to the output of the electronic ballast (10) and is then used to control the power being supplied to the dc-powered lighting equipment (26). The maximum power delivered to the dc-powered lighting equipment (26) is substantially equal to the rated output power of the electronic ballast (10). A switching converter is acted as the necessary input impedance for the electronic ballast (10). Thus, the active power and reactive power drawn from the electronic ballast (10) can be controlled. The output of the switching converter provides dc power for the dc-powered lighting equipment (26).

Abstract: An apparatus that can operate with electronic ballasts (10) for electric discharge lamps to drive dc-powered lighting equipment (26) is provided. The apparatus is directly connected to the output of the electronic ballast (10) and is then used to control the power being supplied to the dc-powered lighting equipment (26). The maximum power delivered to the dc-powered lighting equipment (26) is substantially equal to the rated output power of the electronic ballast (10). A switching converter is acted as the necessary input impedance for the electronic ballast (10). Thus, the active power and reactive power drawn from the electronic ballast (10) can be controlled. The output of the switching converter provides dc power for the dc-powered lighting equipment (26).

Abstract: An output compensator for a regulator is provided that can improve the dynamic response of a regulator, and which does not require the redesigning of the power conversion stage or control stage of the regulator, but simple circuit connection of the compensator circuit to the output stage of the regulator. The compensator senses an output signal at a passive component at an output of the regulator; generates a compensating signal based on a difference signal, the difference being a difference between a level of a reference signal for the regulator and the sensed output signal; and applies the compensating signal to the passive output component to reduce the difference between the level of the reference signal and the sensed output signal. The passive output component may be, for example, a capacitor or an inductor, depending on the operation of the regulator.

Abstract: Reducing, suppressing or canceling parallel parasitic capacitance and/or resistive effects that affect the frequency response of components, elements and/or circuits in an electronic circuit or system that exhibit inductance is disclosed. Noise generated by parallel parasitic capacitance and/or parasitic resistance of the components, the physical orientation of the components, and/or the layout of components, devices and/or conductive tracks (board traces) on printed circuit boards within an electronic circuit or system is reduced, suppressed or canceled. The reduction, suppression or cancelation is achieved by adding a current source in parallel with a part or component of the electronic circuit or system that exhibits inductance, the current source being adapted to deliver a compensating current of roughly equal magnitude and roughly opposite phase to parasitic current associated with the part or component.

Abstract: Reducing, suppressing or canceling series parasitic inductance and/or resistive effects that affect the frequency response of components, elements and/or circuits in an electronic circuit or system that exhibit capacitance is disclosed. Noise generated by series parasitic inductance and/or parasitic resistance of the components, the physical orientation of the components, and/or the layout of components, devices and/or conductive tracks (board traces) on printed circuit boards within an electronic circuit or system is reduced, suppressed or canceled. The reduction, suppression or cancellation is achieved by adding a voltage source in series with a part or component of the electronic circuit or system that exhibits capacitance, the current source being adapted to deliver a compensating voltage of roughly equal magnitude and roughly opposite phase to parasitic voltage associated with the part or component.

Abstract: The present invention provides an apparatus and method for tracking the maximum power point of a solar panel. A pulsewidth-modulated converter, for example a SEPIC or Cuk converter, is provided between the output of the panel and the load, and a perturbation is introduced into a switching parameter of the converter.

Abstract: The present invention provides an apparatus and method for tracking the maximum power point of a solar panel. A pulsewidth-modulated converter, for example a SEPIC or Cuk converter, is provided between the output of the panel and the load, and a perturbation is introduced into a switching parameter of the converter.

Abstract: This invention relates to dimmable electronic ballasts for particular use with fluorescent lamps.

Abstract: Novel structures for electronically-controlled integral compact fluorescent lamps are described in which the space defined by a folded discharge tube is used to locate a housing for at least a part of the electronic-control circuitry. The housing is provided with ventilation means to allow the escape of heated air from the interior of the housing. This reduces the size of the lamp, and allows temperature sensitive components to be located in a relatively cool region. The housing can be provided with a reflective coating to improve the illumination uniformity, and if made of metal can act as a heat sink.

Abstract: Novel structures for electronically-controlled compact fluorescent lamps are described in which the space defined by a folded discharge tube is used to locate a housing for at least a part of the electronic-control circuitry. This reduces the size of the lamp, and allows temperature sensitive components to be located in a relatively cool region. The housing can be provided with a reflective coating to improve the illumination uniformity, and if made of metal can act as a heat sink.

Abstract: This invention relates to dimmable electronic ballasts for particular use with fluorescent lamps.

Abstract: Apparatus and methods are described for the voltage control of power converters in which the input and output voltages of the converter are not sensed directly but are derived from an inductor voltage which in turn is derived by sensing an instantaneous inductor current.