A method includes operating a power converter in a first mode of operation, where the power converter includes multiple first switches and multiple boost diodes coupled to multiple first rails. Each first rail is also coupled to a different one of multiple boost inductors, and the power converter is coupled to multiple second rails. The power converter in the first mode converts electrical power transported between the first and second rails. The method also includes, during the first mode of operation, operating multiple second switches coupled in parallel across the boost diodes as synchronous switches. Each second switch is coupled across a different one of the boost diodes. The method further includes switching the power converter to a second mode of operation in which the first switches are deactivated and the second switches and the boost diodes operate as a full-bridge power converter.

A power converter circuit includes a rectifier circuit having first and second input terminals that receive an AC input voltage and first and second output terminals that output a DC bus voltage, and a series circuit comprising a switch connected in series with an input capacitor connected across the first and second output terminals. A controller controls the switch so that the switch is on at least during a period when a magnitude of the AC input voltage is less than a selected DC bus voltage, and the switch is off during a period when the magnitude of the AC input voltage is greater than the selected DC bus voltage and less than a peak value of the AC input voltage. Power adapters incorporating these features benefit from low component count, reduced component current stress, reduced size and weight, and low cost, making then suitable for a range of portable devices such as laptop computers and cellphones.

A standby power consumption control device for a lighting system, includes a power factor correction module; first functional module for assisting in improving a power factor, the first functional module being located at an output end of a rectifier module of the lighting system and electrically connected to the power factor correction module; second functional module for assisting in improving a power factor, the second functional module being electrically connected to an output end of the power factor correction module; and a control module electrically connected to the first functional module, the second functional module, and the power factor correction module; the control module can control the first functional module, the second functional module, and the power factor correction module to be synchronously turned on or off according to a working state of the lighting system.

A dimmable induction RF fluorescent lamp comprising a dimming circuit enabling the induction RF fluorescent lamp to dim in response to a signal from an external dimming circuit, and having a main mercury amalgam having a vapor pressure at room temperature which is higher than the vapor pressure of the mercury amalgam formed on the flag.

A method and apparatus for detection of a failure of a rectifier connected to a passive harmonic filter with a tuned circuit reactor, or of the filter itself, using low cost voltage sensing, modeling of reactor resistance and saturable inductance, and a mathematical integration. The harmonic spectrum of the rectifier current is used to determine an estimate of the rectifier impedance. A template of expected rectifier current is calculated, and compared against a rectifier current calculated on the basis of sensed voltages, to generate a difference signal. The difference signal is compared against a predetermined fault threshold to determine if an error has occurred. The apparatus includes a DSP obtaining the voltages of the source and load, and the tuned circuit reactor voltage, and configured to compare the currents calculated from the actual voltages with the currents in the template, and to thereby determine whether to annunciate a fault.

A circuit for shaping an input current of a switching power converter. The circuit is a power factor circuit comprising an input to be coupled to receive a rectified line signal, an output, a resistance coupled to resist a flow of current from the input to the output. The resistance has a first value and a switch coupled in parallel with the resistance and coupled to switch from a less conductive state into a more conductive state in response to the flow of current through the input, and the more conductive state is sufficiently conductive to divert a portion of the current flow away from the resistance.

A method includes operating a power converter in a first mode of operation, where the power converter includes multiple first switches and multiple boost diodes coupled to multiple first rails. Each first rail is also coupled to a different one of multiple boost inductors, and the power converter is coupled to multiple second rails. The power converter in the first mode converts electrical power transported between the first and second rails. The method also includes, during the first mode of operation, operating multiple second switches coupled in parallel across the boost diodes as synchronous switches. Each second switch is coupled across a different one of the boost diodes. The method further includes switching the power converter to a second mode of operation in which the first switches are deactivated and the second switches and the boost diodes operate as a full-bridge power converter.

A switch power supply having active power factor correction is provided, including a power factor correction (PFC) circuit, a filter circuit, a main power stage, a first capacitor and an indicating circuit. The indicating circuit consists of a light emitting diode (LED) and an inductor; and the current direction of power supplied from the PFC circuit to the main power stage through the inductor is opposite to the conduction direction of the LED. The filter circuit at least comprises an electrolytic capacitor. When the electrolytic capacitor is normal, the LED does not emit light. When the equivalent series resistance (ESR) of the electrolytic capacitor sharply rises, the exciting current appears in the inductor. When a power transistor in the main power stage is switched off, the exciting current passes through the LED for freewheeling and enables the LED to emit light.

A standby power consumption control device for lighting system, the standby power consumption control device comprising power factor correction module; first functional module for assisting in improving a power factor, the first functional module being located at an output end of the rectifier module of the lighting system and electrically connected to the power factor correction module; second functional module for assisting in improving a power factor, the second functional module being electrically connected to an output end of the power factor correction module; the standby power consumption control device further comprising control module electrically connected to the first functional module, the second functional module, and the power factor correction module; the control module can control the first functional module, the second functional module, and the power factor correction module to be synchronously turned on or off according to the working state of the lighting system.

An RF fluorescent lamp, comprising a bulbous vitreous portion of the RF fluorescent lamp comprising a vitreous envelope filled with a working gas mixture, a power coupler to induce an alternating electric field within the vitreous envelope, an electronic ballast, and a mercury amalgam accommodating structure mounted within the lamp envelope and adapted to absorb power from the electric field to rapidly heat and vaporize an amalgam of mercury to rapidly illuminate the lamp envelope during a turn-on phase of the RF fluorescent lamp, wherein the structure is comprised of a substrate material coated with a mixture of indium and gold.