Selectable coil array

摘要

An inductive wireless power system using an array of coils with the ability to dynamically select which coils are energized. The coil array can determine the position of and provide power to one or more portable electronic devices positioned on the charging surface. The coils in the array may be connected with series resonant capacitors so that regardless of the number of coils selected, the resonance point is generally maintained. The coil array can provide spatial freedom, decrease power delivered to parasitic loads, and increase power transfer efficiency to the portable electronic devices.

主权项

1. A coil array system comprising:
one or more driver circuits, each of said one or more driver circuits for generating an AC signal; a plurality of coils arranged in a plurality of layers to form a selectable coil array associated with a charging surface for placing a secondary device, wherein the pluralities of coils are overlapping and successfully layered along a single direction to provide spatial freedom, wherein said selectable coil array includes a plurality of switches operable to selectively and simultaneously electrically connect a subset of two or more of said plurality of coils to one of said one or more driver circuits in order to generate a magnetic field in said subset of said plurality of coils; wherein said selectable coil array including said plurality of coils is operably coupled to said one driver circuit of said one or more driver circuits such that said one driver circuit is operable to provide said AC signal to each of said plurality of coils, wherein said one driver circuit provides said AC signal simultaneously to said subset of two or more of said plurality of coils selectively connected to said one driver circuit via said plurality of switches; wherein each of said plurality of coils is selectively connectable to said one driver circuit such that a number of said plurality of coils that are selectively connected to said driver circuit is variable; wherein each of said plurality of coils is electrically connected with a separate series resonant capacitor, wherein a resonance point of said plurality of coils is maintained independent of the number of coils selectively electrically connected in parallel to said one driver circuit in said coil array system; a position detection circuit for obtaining position information regarding a secondary coil of said secondary device placed on said charging surface; and a controller programmed to operate said selectable coil array as a function of said position information in order to position said magnetic field relative to said position of said secondary device on said charging surface, wherein the number of coils selectively electrically connected to said one driver circuit in said selectable coil array depends at least in part on said secondary device position information.