Det International Holding Limited

Gan Systems Inc.

Puls Gmbh

Delta Electronics (Thailand) Public Company Limited

Wiferion Gmbh

Nigel Springett

Ahmad Mizan

Cameron Mcknight-Macneil

Howard Tweddle

Wolfgang Bitsch

Greg P Klowak

Gregory P Klowak

Darko Vracar

Malhar Bhatt

Efficient measures to improve electrical performance in a mobile side output circuitry of a wireless power transmission system are provided. The mobile side circuitry of the wireless power transmission system has a mobile side transformer stage comprising at least one primary side winding and a plurality of secondary side windings. To the plurality of secondary side windings there are connected a plurality of mobile side AC/DC converters. According to a first alternative of the present invention output terminal pairs of the plurality of mobile side AC/DC converters are connected in series. According to a second alternative of the present invention output terminal pairs of the plurality of mobile side AC/DC converters are connected in parallel. According to a third alternative of the present invention mobile side AC/DC converters are grouped into a plurality of mobile side output groups such that output terminal pairs within each mobile side output group are connected in series and output terminal pairs of different mobile side output groups are connected in parallel.

Wireless power transmission with modular output

A fault tolerant design for large area nitride semiconductor devices is provided, which facilitates testing and isolation of defective areas. A transistor comprises an array of a plurality of islands, each island comprising an active region, source and drain electrodes, and a gate electrode. Electrodes of each island are electrically isolated from electrodes of neighboring islands in at least one direction of the array. Source, drain and gate contact pads are provided to enable electrical testing of each island. After electrical testing of islands to identify defective islands, overlying electrical connections are formed to interconnect source electrodes in parallel, drain electrodes in parallel, and to interconnect gate electrodes to form a common gate electrode of large gate width Wg. Interconnections are provided selectively to good islands, while electrically isolating defective islands. This approach makes it economically feasible to fabricate large area GaN devices, including hybrid devices.

Fault tolerant design for large area nitride semiconductor devices

The invention relates to a power conversion system, wherein a first switch is connected between a input voltage source and a second switch, wherein the second switch is connected to a third switch, wherein the third switch is connected to a fourth switch, wherein the fourth switch is connected to the input voltage source, wherein a first diode is connected between a neutral point and the second switch, wherein a second diode is connected between the third switch and the neutral point. Two or more current transformers are arranged such that a drive signal is produced in an interleaved mode.

Power conversion system

In an AC-AC converter comprising a primary side, a secondary side and a regulator, wherein the regulator comprises a voltage regulation circuit configured to determine an error voltage based on an at least partially alternating feedback voltage fed into the regulator from the secondary side of the AC-AC converter and to supply this error voltage and/or an information about this error voltage to the primary side of the AC-AC converter, the regulator comprises an averaging circuit configured to determine an average DC voltage based on the feedback voltage.

Synchronized isolated AC-AC converter with variable regulated output voltage

A converter transformer () with a primary winding and a secondary winding, an integrated current transformer arranged to measure a winding current of the converter transformer, and a synchronous rectifier () connected to the secondary winding of the converter transformer are provided. A controller is arranged to close respectively to open the synchronous rectifier depending on the measured winding current. The controller is arranged to close and/or to open the synchronous rectifier as a function of the winding current at a later and/or at an earlier time, whereby the time difference between the later and the earlier time is linearly dependent on the winding current difference, particularly to optimize a discharge process, and/or that an auxiliary supply circuit is arranged to provide auxiliary supply power, wherein the auxiliary supply circuit is arranged to derive auxiliary supply power from the integrated current transformer, in particular in overload situations.

Multiple use of a current transformer

A magnetic device to be surface mounted on a substantially planar thermally conductive surface comprises a circuit board containing a winding pattern having at least one winding and a magnetic core that is at least partially encompassing the winding pattern. On a bottom side of the circuit board a region corresponding to a substantial part of the winding pattern is covered by a thermally conductive material for thermally contacting the thermally conductive surface. A transformer arrangement comprises such a magnetic device as well as a thermally clad circuit board having a surface area covered by a thermally conductive material, corresponding to at least substantially the covered region on the bottom side of the circuit board. For assembly, the covered region on the bottom side of the circuit board is soldered to the covered region on the surface of the thermally clad circuit board. The extensive cover and thermal contact to the thermally conductive surface allows for heat transfer from the complete winding area, reducing the total thermal resistance and temperature gradients in the winding structure. The solution is inexpensive and easy to manufacture.

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Emmendingen, Germany

Nigel Springett