A direct-current voltage conversion circuit having on/off control with a dead-time period performed alternately on a first switch and a second switch included in a direct-current voltage conversion circuit. When alternating current flows in a series circuit part including two transformers magnetically independent, current flows in an output circuit including a secondary side of one transformer, and energy is accumulated in the other transformer. The permeabilities of the magnetic cores in the first and second transformers is between 15 and 120.

A transformer includes a magnetic core, a primary side winding and a plurality of secondary side windings. The magnetic core includes a first outer column, a second outer column, an upper cover and a lower cover. The first outer column and the second outer column are disposed between the upper cover and the lower cover. The primary side winding is disposed on the first outer column and the second outer column, and the plurality of secondary side windings are disposed on the first outer column and the second outer column. Each of the secondary windings has one end passing through a region between the first outer column and the second outer column.

A power apparatus comprising a wireless power receiver and a photovoltaic panel including a first p-n junction fabricated via a common process onto a substrate comprising low conductivity.

A low-core-loss transformer for high transfer ratio and high power density applications can have five pillars including four corner pillars and at least one center pillar between magnetic metal plates. The center pillar provides an additional flux path to reduce thermal and core losses and improve efficiency. Magnetic flux density may be further reduced by having multiple central pillars in an N-track configuration in several kinds of symmetrical arrangements. The low-core-loss transformer achieves a flexible voltage transfer ratio. The ratio can be either even or odd numbers. An odd ratio design is able to fulfill the requirement of future data centers to supply a 400-volt high-distribution power bus. The transformer windings can be traces on a Printed Circuit Board (PCB) that integrate electronic components for a compact and modular design.

Various examples of magnetic integration of matrix transformers with controllable leakage inductance are described. In one example, a transformer includes a magnetic core comprising a plurality of core legs and a leakage core leg. The leakage core leg is positioned among the plurality of core legs to control a leakage inductance of the transformer. The transformer also includes a planar winding structure. The planar winding structure includes a primary winding and a plurality of secondary windings. The primary winding and the plurality of secondary windings extend in a number of turns around the plurality of core legs, without a turn around the leakage core leg, to further control the leakage inductance of the matrix transformer.

A power conversion circuit has a multilayer transformer and a plurality fo rectifying transistors coupled to the secondary windings of the multilayer transformer. The multilayer transformer is formed as multiple layers within a PCB stack, where primary winding conductors and secondary winding conductors are vertically aligned and stacked. The secondary winding conductors are constructed to have one or more secondary winding arms that provide area to which the plurality of rectifying transistors are physically connected. The primary winding conductors are constructed to have a primary winding arm. A footprint of each primary winding conductor is configured to substantially overlap an entire footprint of each of the secondary winding conductors. As such, an entirety of the secondary current flowing through the secondary winding conductors is vertically aligned with the primary winding conductors, and therefore with the primary current flowing through the secondary winding conductors.

The present disclosure discloses a charging device, a charging method, a power adapter and a terminal. The charging device includes a charging receiving terminal, a voltage adjusting circuit and a central control module. The charging receiving terminal is configured to receive an alternating current. The voltage adjusting circuit includes a first rectifier, a switch unit, a transformer and a second rectifier. The first rectifier is configured to rectify the alternating current and output a first voltage. The switch unit is configured to modulate the first voltage to output a modulated first voltage. The transformer is configured to output a second voltage according to the modulated first voltage. The second rectifier is configured to rectify the second voltage to output a third voltage. The voltage adjusting circuit applies the third voltage to a battery directly.

The present invention relates to a wireless charging system using a wireless charging system, and a device therefor. A wireless power receiving device according to one embodiment of the present invention may comprise: first to N.sup.th receiving coils disposed to be partially overlapped on the same plane so as to receive wireless power signals; first to N.sup.th output terminals formed to enable both ends of each of the first to N.sup.th receiving coils to be connected thereto so as to transfer alternating current power induced by at least any one among the first to N.sup.th receiving coils; and a rectifier for converting, into direct current power, the alternating current power to be input from the first to N.sup.th output terminals. Therefore, the present invention has an advantage of minimizing charging interruptions and minimizing manufacturing costs of a wireless power transmitting device.

The present disclosure discloses a charging device, a charging method, a power adapter and a terminal. The charging device includes a charging receiving terminal, a voltage adjusting circuit and a central control module. The charging receiving terminal is configured to receive an alternating current. The voltage adjusting circuit includes a first rectifier, a switch unit, a transformer and a second rectifier. The first rectifier is configured to rectify the alternating current and output a first voltage. The switch unit is configured to modulate the first voltage to output a modulated first voltage. The transformer is configured to output a second voltage according to the modulated first voltage. The second rectifier is configured to rectify the second voltage to output a third voltage. The voltage adjusting circuit applies the third voltage to a battery directly.

The present disclosure discloses a charging method, a power adapter and a charging device. The power adapter includes: a first rectification unit, configured to rectify a first alternating current and output a voltage with a first pulsating waveform; a switch unit, configured to modulate the voltage according to a control signal; a transformer, configured to output a plurality of voltages with pulsating waveforms according to the modulated voltage; a synthesizing unit, configured to synthesis the plurality of voltages to output a second alternating current; a sampling unit, configured to sample voltage and/or current of the second alternating current to obtain a voltage sampling value and/or a current sampling value; and a control unit, configured to output the control signal to the switch unit, and to adjust a duty ratio of the control signal according to the current sampling value and/or the voltage sampling value.