A dual-input power supply has two power paths that connect a server to electrical Each power path has a first stage that comprises a power-factor correction circuit. The power paths share a common second stage that comprises a dc/dc converter. The first stages of the power paths collectively defining a pair of first stages that is disposed either within a package that is off the motherboard or without a package and on the motherboard. Similarly, the second stage is disposed either within a package that is off the motherboard or without a package and on the motherboard.

A control circuit includes: an output terminal configured to be coupled to a control terminal of a transistor that has a current path coupled to an inductor; a transconductance amplifier configured to produce a sense current based on a current flowing through the current path of the transistor; and a first capacitor, where the control circuit is configured to: turn on the transistor based on a clock signal, integrate the sense current with an integrating capacitor to generate a first voltage, generate a second voltage across the first capacitor based on a first current, generate a second current based on the second voltage, generate a third voltage based on the second current, turn off the transistor when the first voltage becomes higher than the third voltage; discharge the integrating capacitor when the transistor turns off; and regulate an average output current flowing through the inductor based on the first current.

A multiple output universal serial bus travel adaptor includes: at least one AC-DC converter for converting an AC power to a first DC power; at least one DC-DC converter for providing a second DC power according to the first DC power; plural switches which are coupled to the AC-DC converter and/or the DC-DC converter to provide the first DC power or the second DC power to corresponding connectors according to operation signals; and a protocol controller configured to generate the operation signals according to at least one of the following parameters: a) the types of the connectors; b) whether there is a mobile device connected with the connectors; c) a first command from the mobile device; d) the power consumed by the mobile devices; e) the currents flowing through the connectors; and f) the voltages at the connectors.

An AC/DC power converter includes input terminals, output terminals, a power factor correction circuit coupled between the input and output terminals and including at least one power switch defining a switched current path, and a current transformer including a primary winding and a secondary winding. The primary winding is coupled in series with the switched current path. The power converter also includes a first sense switch coupled with a first end of the secondary winding, a second sense switch coupled with a second end of the secondary winding, and a control circuit. The control circuit is configured to turn on the first sense switch and turn off the second sense switch during a positive polarity of the AC voltage input, and to turn off the first sense switch and turn on the second sense switch during a negative polarity of the AC voltage input.

An electronic transformer including a controller and a dimming control circuit. The controller is configured to control an output voltage. The dimming control circuit is configured to receive a user-input and output a control signal based on the user-input. The controller varies the output voltage based on the control signal. Wherein the output voltage is substantially the same regardless of an amplitude of an input voltage.

A control device for controlling a switching converter includes a switch controller that generates a control signal with a switching period for controlling switching of a switch of the switching converter and setting a first interval in which a current flows in the switch, a second interval in which energy is transferred onto a storage element of the switching converter, and a third, wait, interval, at the end of the second interval. The duration of the first interval is determined based on a control voltage indicating the output voltage. A pre-distortion stage receives the control voltage and generates a pre-distorted control voltage as a function of the control voltage and a relationship between one of the first and third time intervals and the switching period, wherein the switch controller is configured to control a duration of the first interval based on the pre-distorted control voltage.

A micro-electro-mechanical device, wherein a platform is formed in a top substrate and is configured to turn through a rotation angle. The platform has a slit and faces a cavity. A plurality of integrated photodetectors is formed in a bottom substrate so as to detect the light through the slit and generate signals correlated to the light through the slit. The area of the slit varies with the rotation angle of the platform and causes diffraction, more or less marked as a function of the angle. The difference between the signals of two photodetectors arranged at different positions with respect to the slit yields the angle.

A primary-side controlled high power factor, low total harmonic distortion, quasi resonant converter converts an AC mains power line input to a DC output for powering a load, such as a string of LEDs. The AC mains power line input is supplied to a transformer that is controlled by a power switch. A device for controlling a power transistor of a power stage includes a shaper circuit including a first current generator configured to output a first current responsive to a bias voltage signal and to generate a reference voltage signal based on the first current. A bias circuit includes a second current generator configured to output a second current responsive to a compensation voltage signal and to generate the bias voltage based on the second current. An error detection circuit includes a third current generator configured to output a third current responsive to the reference voltage signal and to generate the compensation voltage signal based on the third current. A driver circuit has a first input configured to receive the reference voltage signal and having an output configured to drive the power transistor.

Provided are a power supply conversion device and a charging control method. The device includes: a transformer; a first rectifier circuit connected to a primary winding of the transformer used for converting a received alternating current into a first direct current, a voltage value of the first direct current being a first direct-current voltage, and the transformer used for converting the first direct-current voltage into a second direct-current voltage; a voltage converter connected to a secondary winding of the transformer and used for converting the second direct-current voltage to output a constant direct-current voltage or a pulsating direct-current voltage; and a controller connected to the first rectifier circuit and the voltage converter and used for controlling the voltage converter to selectably output the constant direct-current voltage or the pulsating direct-current voltage according to a desired charging mode of a device to be charged connected to the power supply conversion device.

An integrated single stage ac-dc driver for powering LED loads includes a boost converter operating in a Discontinuous Conduction Mode, DCM, comprising a half-bridge, and a Zeta Asymmetrical Half Bridge, ZAHB, integrated with the boost converter such that the boost converter and the ZAHB share the half-bridge to perform power factor control, PFC, with a fixed duty cycle and control an output voltage.