Contact-less power transfer

• US 20060076922A1
• Filed: 11/22/2005
• Published: 04/13/2006
• Est. Priority Date: 05/13/2002
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: James Westwood Hay, Lily Ka-Lai Cheng, Pilgrim Giles William Beart
• Inventors: Beart, Pilgrim Giles William, Cheng, Lily Ka-Lai, Hay, James Westwood
• Granted Patent: US 7,248,017 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

There is disclosed a system and method for transferring power without requiring direct electrical conductive contacts. There is provided a primary unit having a power supply and a substantially laminar charging surface having at least one conductor that generates an electromagnetic field when a current flows therethrough and having an charging area defined within a perimeter of the surface, the at least one conductor being arranged such that electromagnetic field lines generated by the at least one conductor are substantially parallel to the plane of the surface or at least subtend an angle of 45° or less to the surface within the charging area; and at least one secondary device including at least one conductor that may be wound about a core. Because the electromagnetic field is spread over the charging area and is generally parallel or near-parallel thereto, coupling with flat secondary devices such as mobile telephones and the like is significantly improved in various orientations thereof.

Claims

1. A portable electrical or electronic device, adapted to receive power inductively from an external unit that has a field generating surface and a field generator which generates an electromagnetic field at or over the field generating surface, the device being adapted to receive power from the external unit when placed in an intended power-receiving disposition on or in proximity to said field generating surface and being separable from the external unit when not receiving power therefrom, the device comprising:

a housing including a predetermined portion having an external surface which faces said field generating surface when the device is placed in said power-receiving disposition, said predetermined portion also having an internal surface; and

a magnetic core component arranged within said housing on or in proximity to said internal surface of said predetermined portion so that the core component couples with said field when the device is in its said power-receiving disposition, the magnetic core component including a thin sheet of magnetic material and also including a coil wound around said sheet for receiving power inductively from the external unit, the sheet and the coil being arranged so that a longitudinal axis of said sheet and a central axis of said coil each extend generally parallel to said field generating surface when the device is in said power-receiving disposition.

2. A portable electrical or electronic device as claimed in claim 1, wherein said thin sheet is substantially flat.

3. A portable electrical or electronic device as claimed in claim 1, wherein said thin sheet is curved.

4. A portable electrical or electronic device as claimed in claim 1, wherein said coil extends in its axial direction over a distance that is large compared to a thickness of said magnetic core component.

5. A portable electrical or electronic device as claimed in claim 1, wherein the largest dimension of said thin sheet is in the direction of said central axis of said coil.

6. A portable electrical or electronic device as claimed in claim 1, wherein said magnetic material is amorphous magnetically permeable material.

7. A portable electrical or electronic device as claimed in claim 1, wherein said magnetic core component has two such coils, the respective central axes of said two coils extending in mutually orthogonal directions generally parallel to said field generating surface when the device is in said power-receiving disposition.

8. A rechargeable battery adapted to receive power inductively from an external unit when fitted into a battery holder in a portable electrical or electronic device, the external unit having a field generating surface and a field generator which generates an electromagnetic field at or over the field generating surface, and the device being adapted to be placed in an intended power-receiving disposition on or in proximity to said field generating surface of the external unit when the battery is to be recharged, and the device comprising a housing including a predetermined portion having an external surface which faces said field generating surface when said device is placed in its said power-receiving disposition, the battery comprising:

a magnetic core component carried in or by said battery in such a way that when the battery is retained by said battery holder and said device is in its said power-receiving disposition the core component is in proximity to said internal surface of said predetermined portion and couples with the field, the magnetic core component including a thin sheet of magnetic material and also including a coil wound around said sheet for receiving power inductively from the external unit, the sheet and the coil being arranged so that a longitudinal axis of the sheet and a central axis of the coil each extend generally parallel to said field generating surface when the battery is retained in said battery holder and the device is in its said power-receiving disposition.

9. A rechargeable battery as claimed in claim 8, wherein said thin sheet is substantially flat.

10. A rechargeable battery as claimed in claim 8, wherein said thin sheet is curved.

11. A rechargeable battery as claimed in claim 8, wherein said coil extends in its axial direction over a distance that is large compared to a thickness of said magnetic core component.

12. A rechargeable battery as claimed in claim 8, wherein said magnetic material is amorphous magnetically permeable material.

13. A rechargeable battery as claimed in claim 8, wherein:

the battery holder is adapted to retain the battery in the device with its longitudinal axis extending generally parallel to said field generating surface when the device is in its said power-receiving disposition; and

the sheet and the coil are arranged so that said longitudinal axis of the sheet and said central axis each extend generally parallel to said field generating surface when the battery is so retained in said battery holder and the device is in its said power-receiving disposition.

14. A rechargeable battery as claimed in claim 8, wherein the magnetic core component is at least partially wrapped around an axis of the battery such that it couples with an electromagnetic field generated by said external unit in any rotation about the axis when the device is in its said power-receiving disposition and the battery is retained in said battery holder.

15. A rechargeable battery adapted to receive power inductively from a primary unit when fitted into a space in a portable electrical or electronic device, the device comprising a cover element having a substantially planar portion with inner and outer surfaces and being adapted to be placed with said outer surface on or in proximity to such a primary unit when the battery is to be recharged, and the device being adapted to retain the battery in the space with its longitudinal axis extending generally parallel to a plane of said planar portion, the battery comprising:

a power-receiving element comprising a coil which is in close proximity to said inner surface of said cover element when the cell is so retained in said space and which has a central axis that extends generally parallel to a plane of said planar portion, for receiving power inductively from the primary unit when the device is so placed on or in proximity to the primary unit; and

a rechargeable energy-storing element connected to the power-receiving element for storing the power received inductively by the power-receiving element;

wherein said power-receiving element is in the form of a thin sheet.

16. A rechargeable battery as claimed in claim 15, wherein said thin sheet is substantially flat.

17. A rechargeable battery as claimed in claim 15, wherein said thin sheet is curved.

18. A rechargeable battery as claimed in claim 15, wherein said power-receiving element further comprises a core of magnetic material, said core having a longitudinal axis which extends generally parallel to said plane.

19. A rechargeable battery as claimed in claim 18, wherein said coil is wound about said core.

20. A rechargeable battery as claimed in claim 18, wherein said coil extends in its axial direction over a distance that is large compared to a thickness of said power-receiving element.

21. A rechargeable battery as claimed in claim 18, wherein said core is made of amorphous magnetically permeable material.

22. A rechargeable battery as claimed in claim 15, wherein said power-receiving element has two such coils, the respective central axes of said two coils extending in mutually orthogonal directions generally parallel to said plane.

23. A rechargeable battery as claimed in claim 15, wherein said portable electrical or electronic device has a metal plane extending generally parallel to said plane of said planar portion of said cover element.

24. A rechargeable battery as claimed in claim 15, wherein the portable electrical or electronic device has a printed circuit board extending generally parallel to a plane of said planar portion of said cover element.

25. A rechargeable battery as claimed in claim 15, wherein said planar portion of said cover element includes metal.

26. A rechargeable battery as claimed in claim 18, wherein, when the battery is retained in said space, said core is located between said cover element and components of the device susceptible to electromagnetic fields so that the core can serve to reduce the effects on such components of an electromagnetic field generated by the primary unit.

27. A rechargeable battery as claimed in claim 15, wherein said rechargeable battery further comprises a power conversion unit which converts power received inductively by the power-receiving element into a form suitable for delivery to outside said battery through external electrical connections thereof, or into a form suitable for recharging the energy-storing element, or into both said forms.

28. A rechargeable battery as claimed in claim 27, wherein said rechargeable battery has a charge-control unit operable, when the power-receiving element is receiving power inductively, to meter the supply of inductively-received power to the external electrical connections and to the energy-storing element.

29. A rechargeable battery as claimed in claim 15, having an enclosure and external electrical connections similar in dimensions to an industry-standard battery.

30. A rechargeable battery adapted to receive power inductively from a primary unit when fitted into a space in a portable electrical or electronic device, the device comprising a cover element having a substantially planar portion with inner and outer surfaces and being adapted to be placed with said outer surface on or in proximity to such a primary unit when the battery is to be recharged, and the device being adapted to retain the battery in the space with its longitudinal axis extending generally parallel to a plane of said planar portion, the battery comprising:

a power-receiving element comprising a coil which is in close proximity to said inner surface of said cover element when the cell is so retained in said space and which has a central axis that extends generally parallel to a plane of said planar portion, for receiving power inductively from the primary unit when the device is so placed on or in proximity to the primary unit; and

a rechargeable energy-storing element connected to the power-receiving element for storing the power received inductively by the power-receiving element;

wherein a thickness of said power-receiving element, measured in a direction perpendicular to said plane, is small relative to the dimensions of the power-receiving element parallel to said plane.

39. A rechargeable battery as claimed in claim 30, wherein said rechargeable battery has a charge-control unit operable, when the power-receiving element is receiving power inductively, to meter the supply of inductively-received power to the external electrical connections and to the energy-storing element.

31. A rechargeable battery adapted to receive power inductively from a primary unit, the battery comprising:

a generally cylindrical body having a central axis;

a power-receiving element, comprising a coil having a central axis extending generally in parallel with said central axis of said body, for receiving power inductively from the primary unit when the battery is placed on or in proximity to a power transfer surface of the primary unit with said central axis of said body lying across the surface; and

a rechargeable energy-storing element connected to said power-receiving element for storing the power received inductively by the power-receiving element;

wherein said power-receiving element is in the form of a thin sheet.

32. A rechargeable battery as claimed in claim 31, wherein said thin sheet is curved.

33. A rechargeable battery as claimed in claim 31, wherein said thin sheet is wrapped circumferentially around said body or around another generally cylindrical component of the battery.

34. A rechargeable battery as claimed in claim 31, wherein said power-receiving element further comprises a core of magnetic material, said core having a longitudinal axis which extends generally parallel to said central axis of said body.

35. A rechargeable battery as claimed in claim 34, wherein said coil is wound about said core.

36. A rechargeable battery as claimed in claim 34, wherein said coil extends in its axial direction over a distance that is large compared to a thickness of said power-receiving element.

37. A rechargeable battery as claimed in claim 34, wherein said core is made of amorphous magnetically permeable material.

38. A rechargeable battery as claimed in claim 31, wherein said rechargeable battery further comprises a power conversion unit which converts power received inductively by the power-receiving element into a form suitable for delivery to outside said battery through external electrical connections thereof, or into a form suitable for recharging the energy-storing element, or into both said forms.

40. A rechargeable battery as claimed in claim 31, having an enclosure and external electrical connections similar in dimensions to an industry-standard battery.