Wireless power system and method with improved alignment

• US 8,912,686 B2
• Filed: 11/01/2011
• Issued: 12/16/2014
• Est. Priority Date: 11/04/2010
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Stoner, William T. Jr., Moore, Colin J., Moes, Benjamin C., Schwannecke, Joshua K., Baarman, David W., Weber, Richard J., Schamper, Ryan D.
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): SHIAO, DAVID A
• Application Number:
  US13/286,428
• Publication Number:
  US 20120112553A1
• Time in Patent Office: 1,141 Days
• Field of Search: None
• US Class Current: 307/104
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01F 7/0247 Orientating, locating, transporting arrangements
• 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 7/0047 with monitoring or indicating devices or circuits

Abstract

A wireless power system that may align a portable electronic device with an inductive wireless power supply. The induction coils used for transferring power wirelessly may be used as DC electromagnets to align the portable electronic device with the inductive wireless power supply. A DC current may be supplied to the primary coil and to the secondary coil to generate DC electromagnetic fields and attractive force between the primary and secondary coils. This attractive force may be used for alignment.

Claims

1. An inductive power supply with magnetic attraction, said inductive power supply for transferring power wirelessly to a remote device, said inductive power supply comprising:

a primary capable of transferring power wirelessly via an inductive coupling;

a controller for controlling a supply of current to said primary, wherein said current includes direct current and alternating current;

wherein in response to supplying said alternating current to said primary, said primary transfers power wirelessly to said remote device;

wherein in response to supplying said direct current to said primary, an attractive force capable of aligning said remote device for more efficient wireless power transfer is produced; and

a frictional material coupled to a first magnet, wherein said direct current supplied to said primary attracts said first magnet and causes said frictional material to retract such that said frictional material is prevented from contacting a surface of the remote device.

2. The inductive power supply of claim 1 wherein said direct current supplied to said primary generates a DC magnetic field that interacts with a secondary magnetic material in said remote device.

3. The inductive power supply of claim 2 wherein said DC magnetic field has a first magnetic moment and said secondary magnet has a secondary magnetic moment, where said first magnetic moment is aligned in a same direction as said secondary magnetic moment.

4. The inductive power supply of claim 2 wherein said secondary magnetic material is a secondary permanent magnet or a secondary magnetic attractor.

5. A method for aligning an inductive power supply with an electronic portable device using magnetic attraction comprising the steps of:

supplying DC current through a first coil;

providing a DC magnetic field that interacts with the DC current through the first coil;

retracting, in response to the DC current through the first coil, a frictional material coupled to a first magnet such that the frictional material is prevented from contacting an opposing surface; and

aligning the inductive power supply with the electronic portable device for efficient power transfer using the attractive force caused by the interaction of the DC current and the DC magnetic field.

6. The method of claim 5 wherein the DC magnetic field is produced from the inductive power supply and the first coil is a secondary inductor in the electronic portable device, and wherein the opposing surface is a surface of the inductive power supply.

7. The method of claim 5 wherein the DC magnetic field is produced from the electronic portable device and the first coil is a primary inductor in the inductive power supply, and wherein the opposing surface is a surface of the electronic portable device.

8. The method of claim 5 wherein the DC magnetic field is generated by at least one of a magnet and supplying DC current through a second coil.

9. A wireless power supply with magnetic attraction comprising:

an inductive power supply having a primary inductor for transferring power wirelessly to an electronic device having a secondary inductor that receives power from said primary inductor via inductive coupling;

a first DC magnetic field generated by a DC current through a first coil;

a second DC magnetic field, wherein said second DC magnetic field interacts with said DC current through said first coil to cause alignment of said inductive power supply with said electronic device for efficient power transfer; and

a frictional material coupled to a first magnet, wherein said DC current supplied to said first coil attracts said first magnet and causes said frictional material to retract such that said frictional material is prevented from contacting an opposing surface.

10. The wireless power supply of claim 9 wherein said first coil is said primary inductor and said first DC magnetic field originates from said inductive power supply, and wherein said opposing surface is a surface of the electronic device.

11. The wireless power supply of claim 9 wherein said first coil is said secondary inductor and said first DC magnetic field originates from said electronic device, and wherein said opposing surface is a surface of the inductive power supply.

12. The wireless power supply of claim 9 wherein said second DC magnetic field is generated by at least one of a magnet and a DC current supplied to a second coil.

13. The wireless power supply of claim 12 wherein said magnet is a permanent magnet or a magnetic attractor.

14. The wireless power supply of claim 9 wherein said first DC magnetic field is supplemented with a magnet.

15. The wireless power supply of claim 9 further comprising a plurality of primary inductors forming an array.

16. The wireless power supply of claim 15 wherein said DC current is supplied to at least one of said plurality of primary inductors to cause alignment of said inductive power supply with said electronic device for efficient power transfer.

17. A friction enhancement system for a wireless power system, said wireless power system including a wireless power supply and a portable electronic device capable of receiving wireless power, said wireless power supply having a surface for placing said portable electronic device, said friction enhancement system comprising:

a frictional material selectively moveable between a disengaged position where said portable electronic device is capable of sliding over said surface and an engaged position where said frictional material increases friction between said wireless power supply and said portable electronic device thereby reducing said capability to slide said portable electronic device over said surface; and

a magnet coupled to said frictional material, wherein in a presence of a DC magnetic field, said magnet moves said frictional material from a normal state to an alternate state.

18. The friction enhancement system of claim 17 further comprising a dual-use inductive element for use in wireless power transfer and friction enhancement,

wherein an AC current through said dual-use inductive element generates wireless power transfer between said wireless power supply and said portable electronic device;

wherein a DC current through said dual-use inductive element produces said DC magnetic field, wherein said normal state is said engaged position, and wherein said magnet moves said frictional material to said disengaged position as said alternate state such that said surface is free from said frictional material.

19. The friction enhancement system of claim 17 wherein said normal state is said disengaged position, and wherein in said presence of said DC magnetic field, said magnet moves said frictional material to an engaged position as said alternate state.

20. The friction enhancement system of claim 17 further comprising a cavity for use with said disengaged position such that said frictional material enters a retracted position.

21. The friction enhancement system of claim 17 wherein said DC magnetic field is produced by a permanent magnet.

22. The friction enhancement system of claim 17 further comprising a spring-like element that exerts a force on said frictional material such that said frictional material is urged toward said normal state, wherein said frictional material remains in said normal state in absence of said DC magnetic field.

23. The friction enhancement system of claim 17 wherein said magnet is a permanent magnet or a magnetic attractor.

24. The friction enhancement system of claim 17 wherein said frictional material moving to an engaged position provides haptic feedback to a user.

25. The friction enhancement system of claim 17 wherein said surface has a coefficient of friction with respect to said portable electronic device and said coefficient of friction of said surface increases in response to said frictional material moving to said engaged position.