Abstract: For online audio/video conferencing applications deployed in an open office environment, using shared conference devices, it can be advantageous to define an acoustic fence. A non-participant audio received from outside the acoustic fence can be considered noise and filtered out before transmission of an audio signal to a far end recipient. Three suppression stages are used to filter the non-participant audio. The first suppression stage uses beamformers for suppression. The second suppression stage is mask-based, and the third suppression stage is reference-based. The three suppression stages filter out non-participant audio signals, having a wide range of frequencies.

Abstract: A control circuit for a resonant converter, that is configured to: adjust a conduction time of one power switch and a conduction time of one corresponding synchronous rectifier switch in the resonant converter in a resonant period detection mode; control a resonance current to cross zero twice during the conduction time of the synchronous rectifier switch; and obtain a resonant period of the resonant converter.

Abstract: A control circuit for a resonant converter, that is configured to: adjust a conduction time of one power switch and a conduction time of one corresponding synchronous rectifier switch in the resonant converter in a resonant period detection mode; control a resonance current to cross zero twice during the conduction time of the synchronous rectifier switch; and obtain a resonant period of the resonant converter.

Abstract: A rectifier circuit applied in an AC/AC power supply, the rectifier circuit including: a filter circuit configured to receive a DC pulsating voltage, and to generate a supply voltage, where the supply voltage follows the DC pulsating voltage during a first time interval of an operation cycle; and where during a second time interval of the operation cycle, a value of the supply voltage is greater than the value of the supply voltage at an end of the first time interval, in order to reduce a size of the filter circuit.

Abstract: A power factor correction circuit includes a power meter configured to measure a total harmonic distortion (THD) and an amplitude ratio of each harmonic component at an input port; a switching-type regulator that is controllable by a switch control signal in order to adjust a power factor; and a controller configured to generate the switch control signal to control the switching-type regulator to perform power factor correction, where the controller decreases the THD by adjusting a current reference signal according to the measured THD and the amplitude ratio of each harmonic component.

Abstract: A power factor correction circuit includes a power meter configured to measure a total harmonic distortion (THD) at an input port; a switching-type regulator that is controllable by a switch control signal in order to adjust a power factor; and a controller configured to generate the switch control signal to control the switching-type regulator to perform power factor correction, where the controller adjusts an on-time of a main switch of the switching-type regulator based on the measured THD to decrease the THD.

Abstract: A control circuit for a resonant converter, that is configured to: adjust a conduction time of one power switch and a conduction time of one corresponding synchronous rectifier switch in the resonant converter in a resonant period detection mode; control a resonance current to cross zero twice during the conduction time of the synchronous rectifier switch; and obtain a resonant period of the resonant converter.

Abstract: A rectifier circuit applied in an AC/AC power supply, the rectifier circuit including: a filter circuit configured to receive a DC pulsating voltage, and to generate a supply voltage, where the supply voltage follows the DC pulsating voltage during a first time interval of an operation cycle; and where during a second time interval of the operation cycle, a value of the supply voltage is greater than the value of the supply voltage at an end of the first time interval, in order to reduce a size of the filter circuit.

Abstract: A power factor correction circuit includes a power meter configured to measure a total harmonic distortion (THD) and an amplitude ratio of each harmonic component at an input port; a switching-type regulator that is controllable by a switch control signal in order to adjust a power factor; and a controller configured to generate the switch control signal to control the switching-type regulator to perform power factor correction, where the controller decreases the THD by adjusting a current reference signal according to the measured THD and the amplitude ratio of each harmonic component.

Abstract: A power factor correction circuit includes a power meter configured to measure a total harmonic distortion (THD) at an input port; a switching-type regulator that is controllable by a switch control signal in order to adjust a power factor; and a controller configured to generate the switch control signal to control the switching-type regulator to perform power factor correction, where the controller adjusts an on-time of a main switch of the switching-type regulator based on the measured THD to decrease the THD.

Abstract: A power factor correction circuit can include: a power meter configured to measure a power factor at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust the power factor of an input AC power; an EMI filter disposed between the switching-type regulator and the input port; and a controller configured to generate the switching control signal to maximize the power factor by adjusting a current reference signal according to a measured power factor, where the current reference signal represents an expected inductor current of the switching-type regulator.

Abstract: The present invention relates compounds useful as reagents for the diazomethylation reaction, their preparation and the use thereof as reagents in a method for the diazomethylation reaction of aromatic substrates. It relates in particular to a compound of formula (I) wherein E is an electron withdrawing group.

Abstract: The present invention relates compounds useful as reagents for the diazomethylation reaction, their preparation and the use thereof as reagents in a method for the diazomethylation reaction of aromatic substrates. It relates in particular to a compound of formula (I) wherein E is an electron withdrawing group.

Abstract: A power factor correction circuit can include: a power meter configured to measure THD at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust a power factor of an input signal thereof; and a controller configured to generate the switching control signal to control the switching-type regulator to perform power factor correction, where the controller minimizes the THD by adjusting a current reference signal according to a measured THD, and the current reference signal represents an expected inductor current of the switching-type regulator.

Abstract: A power factor correction circuit can include: a power meter configured to measure a power factor at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust the power factor of an input AC power; an EMI filter disposed between the switching-type regulator and the input port; and a controller configured to generate the switching control signal to maximize the power factor by adjusting a current reference signal according to a measured power factor, where the current reference signal represents an expected inductor current of the switching-type regulator.

Abstract: A power factor correction circuit can include: a power meter configured to measure a power factor at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust the power factor of an input AC power; an EMI filter disposed between the switching-type regulator and the input port; and a controller configured to generate the switching control signal to maximize the power factor by adjusting a current reference signal according to a measured power factor, where the current reference signal represents an expected inductor current of the switching-type regulator.

Abstract: Disclosed is a method and a device for detecting states of a battery and a battery pack. The disclosure obtains a first state of charge and a second state of charge of the battery by use of a charge calculation method and a method based on battery model, respectively. The charge calculation method is more accurate when the charge-discharge current is large and the method based on battery model performs better in handling a small current, so that a chemistry state of charge obtained by performing a weighted calculation for the first state of charge and the second state of charge can represent the real state of charge of the battery more precisely. The disclosure settles the difficulty on parameter extraction of the conventional model method, eliminates the influence of the accumulated error of the charge calculation method, and combines the advantages of the method based on the battery model and the coulometer method.

Abstract: A power factor correction circuit can include: a power meter configured to measure THD at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust a power factor of an input signal thereof; and a controller configured to generate the switching control signal to control the switching-type regulator to perform power factor correction, where the controller minimizes the THD by adjusting a current reference signal according to a measured THD, and the current reference signal represents an expected inductor current of the switching-type regulator.

Abstract: A power factor correction circuit can include: a power meter configured to measure THD at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust a power factor of an input signal thereof; and a controller configured to generate the switching control signal to control the switching-type regulator to perform power factor correction, where the controller minimizes the THD by adjusting a current reference signal according to a measured THD, and the current reference signal represents an expected inductor current of the switching-type regulator.