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.

The converter includes: an input direct current (DC) power supply, a main power transistor, an auxiliary power transistor, a first capacitor, a transformer, and a controller. The first capacitor is connected in series to the transformer to form a series circuit. The series circuit is connected in parallel to the auxiliary power transistor. A source of the main power transistor is connected to a drain of the auxiliary power transistor. A source of the auxiliary power transistor is connected to another electrode of the input DC power supply. An input negative electrode of the input DC power supply is grounded. The controller is configured to: monitor a value of a current on the transformer to obtain a quantity of times that the value of the current on the transformer reaches a specified current threshold.

An isolated DC-DC converter includes a non-isolated DC-DC converter as a primary side. The non-isolated DC-DC converter includes a first inductor, a switch controller, and first and second switches. The non-isolated DC-DC converter is configured to receive an input voltage. The non-isolated DC-DC converter also includes a secondary side including a second inductor, a full wave rectifying circuit, and a filter circuit. The second inductor in the secondary side is coupled with the first inductor in the primary side to define a transformer. The secondary side is electrically isolated from the primary side by the transformer and is configured to output a DC voltage based on a voltage induced in the second inductor via the transformer.

A dual-input power conversion system includes a first primary side power network comprising a first hold-up capacitor, wherein the first primary side power network has inputs configured to be coupled to a first power source, and outputs coupled to a transformer, a second primary side power network comprising a second hold-up capacitor, wherein the second primary side power network has inputs configured to be coupled to a second power source, and outputs coupled to the transformer, and a secondary side power network having inputs coupled to a secondary side of the transformer, and outputs coupled to a load, wherein the first primary side power network and the second primary side power network are configured such that a voltage across one of the first hold-up capacitor and the second hold-up capacitor is maintained by a voltage reflected from the secondary side to a corresponding primary side.

A power converter-circuit (100) having a transformer (T), comprising a snubber-circuit (C.sub.sn, D.sub.Sn,S3, S.sub.3, D.sub.Sn,S4) for suppressing voltage peaks on a secondary side of the transformer (T) that comprises a snubber capacitor (C.sub.sn); and an auxiliary DC-DC converter (101) having a first input connected with the snubber capacitor (C.sub.sn) and a first output connected with a first output (V.sub.Out) of the power converter-circuit (100). This circuit increases efficiency of electrical conversion and reduces thermal losses.

Isolated buck converters can be an efficient solution in applications that deal with wide variations in input and/or output voltage. The double ended embodiments of such converters can also offer improved transformer utilization. Such converters can be operated in fixed frequency DCM mode operation or variable frequency boundary conduction mode (BCM). The buck/energy storage inductor may be placed in series with primary or secondary winding of the isolation transformer The inherent leakage inductance of the isolation transformer may also utilized as part of the buck inductance. If the leakage inductance of the isolation transformer is sufficiently high (such as in wireless power transfer applications), such converters can use the leakage inductance as the buck inductor.

A voltage converter, including an input adapted to couple to a voltage source and a transformer including a primary coil and a secondary coil. Primary side circuitry, including a first switching circuit, is coupled to the primary coil. A second switching circuit is coupled between a first terminal and a second terminal of the secondary coil, and configured to selectively close to short circuit the first terminal to the second terminal.

A fully isolated drive circuit to be used for regulating an output voltage across a load. The isolated drive circuit may charge, discharge, or preserve the load charge using a controller that controls one or more switches. The controller may operate a switch according to an internal/external clock or an external control signal received by the controller. The isolated drive circuit may be an effective solution to simplify the drive design and decrease the amount of energy dissipated by the drive, especially when the load, associated with the drive, requires a high input voltage level.

A transformer that can easily cope with various input voltage specifications and that, has improved productivity is obtained. A transformer includes: a core portion for forming a magnetic circuit; and a primary-side winding and a secondary-side winding wound at the core portion. One or both of the primary-side winding and the secondary-side winding are divided into a plurality of division windings, and each of the plurality of the division windings of the at least one divided winding has a wound part wound at the core portion, and two extending members extending from both ends of the wound part. The extending members of the plurality of the division windings of the at least one divided winding are mutually connected, and a number of turns in the transformer of the at least one divided winding is set.

A circuit to rectify an alternating current (AC) signal produced by an output coil of a transformer responsive to an input current in an input coil of the transformer comprises: an output node and a return node coupled to an output load; a first rectifier, coupled to a first terminal of the output coil and the return node, to rectify the AC signal to supply a current to the output node when the input current is ON; a second rectifier, coupled to a second terminal of the output coil and the return node, to rectify the AC signal to supply a current to the output node when the input current is OFF; and a voltage clamp to clamp a first voltage transient and a second voltage transient of the AC signal that occur at the first terminal and the second terminal when the input current is switched OFF and ON.