Access Business Group International LLC

Fen Technology Limited

Philips IP Ventures B.v.

Kevin Alan Lamb

Alexander Charles Knill

John Robert Dunton

Michael Craig Stevens

Andrew Nicolas Dames

A driver circuit for receiving a voltage supply at a supply input and driving a load through a load output, the circuit comprising: a charge inductor and a discharge inductor; a switching array comprising a plurality of switches; and a load switch coupled between a first terminal of the charge inductor and the load output; the switching array being arranged so that: in a first mode it can couple a second terminal of the charge inductor to the supply input and the first terminal of the charge inductor to ground to load a flux on the charge inductor; in a second mode it can decouple the first terminal of the charge inductor from ground so that, when the load switch is closed, flux can flow from the inductor to the load output; and in a third mode it can couple the discharge inductor between the load output and ground so that flux can be loaded on the discharge inductor from the load output.

Driver circuit

An inductive power transfer system () comprises a primary unit () operable to generate an electromagnetic field and at least one secondary device (), separable from the primary unit, and adapted to couple with the field when the secondary device is in proximity to the primary unit so that power can be received inductively by the secondary device from the primary unit without direct electrical conductive contacts therebetween. The system detects if there is a substantial difference between, on the one hand, a power drawn from the primary unit and, on the other hand, a power required by the secondary device or, if there is more than one secondary device, a combined power required by the secondary devices. Following such detection, the system restricts or stops the inductive power supply from the primary unit. Such a system can detect the presence of unwanted parasitic loads in the vicinity of the primary unit reliably.

Controlling inductive power transfer systems

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Chesterton, United Kingdom

Kevin Alan Lamb