Abstract: Embodiments provide an apparatus for controlling conversion between an alternating current and a direct current, including a rectifier circuit, a detection circuit, and a logic circuit, where the detection circuit includes a voltage divider module, a first comparator module, and a second comparator module.

Abstract: A constant current control circuit includes a sample and hold unit coupled to a current sensing resistor of a power converter, for storing a current sensing voltage of the current sensing resistor; a first capacitor for storing a comparison voltage; a discharge unit coupled between the sample and hold unit and the first capacitor, for controlling a discharge current of the first capacitor according to a reference voltage and the current sensing voltage stored in the sample and hold unit; a charge unit coupled to the first capacitor, for controlling a charging current of the first capacitor according to the reference voltage and a ground voltage; and a comparator for comparing the comparison voltage with the reference voltage to generate a comparison result, and outputting a control signal according to the comparison result, in order to control a duty cycle of the power converter.

Abstract: Systems and methods for providing a self-driven synchronous rectification circuit for an active-clamp forward converter which includes automatically enhancing synchronous MOSFETs and maximizing input voltage range. The gate signals for the synchronous MOSFETs are derived from a unipolar magnetic coupling signal instead of a bipolarized magnetic coupling signal. The unipolar signal is retained for fully enhanced driving of the MOSFETs at low line voltage and the unipolar signal is automatically converted to a bipolar signal at high line amplitude due to line variance to maximize input voltage range by utilizing non-polarized characteristics of the MOSFET gate-to-source voltage (Vgs). The circuit permits efficient scaling for higher output voltages such as 12 volts DC or 15 volts DC, without requiring extra windings on the transformer of the forward converter.

Abstract: A power conversion device includes an inverter that drives a motor; a fin that cools down the inverter; a first core including a through hole that allows passage of a positive side conductor that connects a power supply system and the inverter and a negative side conductor that grounds the inverter; a ground conductor that grounds the fin; a ground conductor that grounds a motor yoke via a capacitor; and a ground conductor including one end that is connected to the negative side conductor or the ground conductor and the other end that is grounded.

Abstract: FETs disposed in a DC/DC converter are each driven by a drive transformer. A voltage from a single drive power supply disposed in common for the FETs is divided into positive and negative biases to be applied to the FETs, and an operational state of the FETs is detected based on voltage signals. A sequence circuit turns on an input from a three-phase AC power supply by driving a relay circuit at a time point when it is confirmed that the FETs have normally started stable ON/OFF operation, and drives a power factor improvement circuit, which converts AC voltage from the three-phase AC power supply into a DC voltage by simultaneously performing full-wave rectification and power factor improvement.

Abstract: A low drop out voltage regulator includes an operational transconductance amplifier configured to be supplied with a supply voltage of the regulator, receive as inputs a reference voltage and a feedback voltage, and generate an intermediate current based upon a difference between the reference voltage and the feedback voltage. A current-to-voltage amplification stage is configured to be supplied with a boosted voltage greater than the supply voltage from a high voltage line, receive as input the intermediate current, and generate a driving voltage that is changed based upon the intermediate current. A pass transistor is controlled with the driving voltage to keep constant on a second conduction terminal thereof a regulated output voltage. A feedback network generates the feedback voltage based on the regulated output voltage.

Abstract: An AC/DC converter includes a rectifier circuit and an active power factor correction circuit. The rectifier circuit is electrically connected to a power supply, and is used to convert an alternate current into a direct current, wherein the rectifier circuit has a positive output and a negative output for sending out the direct current. The active power factor correction circuit electrically connects the rectifier circuit and a loading, wherein the active power factor correction circuit is used to suppress voltage ripples provided to the loading.