Wirelessly charged battery system

• US 9,780,573 B2
• Filed: 02/03/2015
• Issued: 10/03/2017
• Est. Priority Date: 02/03/2014
• Status: Active Grant

Abstract

The disclosure features power transmitting apparatus for wireless power transfer to a receiver that includes a housing having a form factor that corresponds to a container featuring lateral surfaces, a bottom surface, and an opening opposite the bottom surface, a first coil formed by a continuous path of electrically conductive material and featuring a plurality of non-planar loops that conform to a first pair of opposite lateral surfaces and to the bottom surface, and a second coil formed by a continuous path of electrically conductive material and featuring a plurality of non-planar loops that conform to a second pair of opposite lateral surfaces and to the bottom surface.

Claims

1. A power transmitting apparatus for wireless power transfer to a receiver, the apparatus comprising:

a housing having a form factor that corresponds to a container comprising lateral surfaces, a bottom surface, and an opening opposite the bottom surface;

a first coil comprising a first plurality of non-planar loops of electrically conductive material, wherein the first plurality of loops conforms to a first pair of opposite lateral surfaces and to the bottom surface; and

a second coil comprising a second plurality of non-planar loops of electrically conductive material, wherein the second plurality of loops conforms to a second pair of opposite lateral surfaces and to the bottom surface.

2. The apparatus of claim 1, wherein the first and second coils are positioned so that during operation of the power transmitting apparatus, the first coil generates a magnetic field having a dipole moment that extends in a first direction, and the second coil generates a magnetic field having a dipole moment that extends in a second direction substantially perpendicular to the first direction.

3. The apparatus of claim 1, wherein the housing comprises a first layer comprising magnetic material.

4. The apparatus of claim 3, wherein the magnetic material comprises a ferrite material.

5. The apparatus of claim 3, wherein the housing comprises a second layer comprising a shielding material.

6. The apparatus of claim 5, wherein the shielding material comprises copper.

7. The apparatus of claim 1, further comprising a third coil comprising a third plurality of non-planar loops of electrically conductive material, wherein the third plurality of loops conforms to each of the lateral surfaces.

8. The apparatus of claim 7, wherein during operation of the power transmitting apparatus, the third coil generates a magnetic field having a dipole moment that extends in a third direction substantially perpendicular to the first and second directions.

9. The apparatus of claim 7, wherein the first, second, and third coils are printed on one or more circuit boards.

10. The apparatus of claim 8, wherein the first and second directions are substantially parallel to a plane defined by the bottom surface, and wherein the third direction is substantially perpendicular to the bottom surface.

11. The apparatus of claim 7, further comprising a control unit connected to each of the first, second, and third coils, wherein during operation, the control unit is configured to:

apply a first oscillating electrical potential to the first coil; and

apply a second oscillating electrical potential to the second coil, wherein the second oscillating electrical potential is out of phase with respect to the first oscillating electrical potential.

12. The apparatus of claim 11, wherein the first and second oscillating electrical potentials are out of phase by about 90°

.

13. The apparatus of claim 11, wherein the control unit is configured to apply a third oscillating electrical potential to a third coil, the third coil comprising a plurality of non-planar loops that conform to each of the lateral surfaces, and to vary a phase difference between and first and third oscillating electrical potentials between 0°

and 90°

.

14. The apparatus of claim 7, further comprising a first decoupling unit connected to the first coil, a second decoupling unit connected to the second coil, and a third decoupling unit connected to the third coil.

15. The apparatus of claim 14, wherein at least one of the decoupling units comprises inductors.

16. The apparatus of claim 14, wherein at least one of the decoupling units comprises inductors connected in parallel to capacitors.

17. The apparatus of claim 16, wherein the capacitors comprise capacitors having a variable capacitance.

18. The apparatus of claim 14, wherein:

the first decoupling unit comprises a first decoupling element configured to reduce magnetic coupling between the first coil and the second coil, and a second decoupling element configured to reduce magnetic coupling between the first coil and the third coil;

the second decoupling unit comprises a third decoupling element configured to reduce magnetic coupling between the second coil and the first coil, and a fourth decoupling element configured to reduce magnetic coupling between the second coil and the third coil; and

the third decoupling unit comprises a fifth decoupling element configured to reduce magnetic coupling between the third coil and the first coil, and a sixth decoupling element configured to reduce magnetic coupling between the third coil and the second coil.

19. The apparatus of claim 18, wherein each of the first, second, third, fourth, fifth, and sixth decoupling elements comprises an inductor, and wherein the control unit is configured to adjust positions of the first, second, third, fourth, fifth, and sixth decoupling elements to reduce magnetic coupling between the first, second, and third coils.

20. The apparatus of claim 18, wherein each of the first, second, third, fourth, fifth, and sixth decoupling elements comprises an inductor connected in parallel to a capacitor having a variable capacitance, and wherein the control unit is configured to adjust capacitances of each of the capacitors in the first, second, third, fourth, fifth, and sixth decoupling elements to reduce magnetic coupling between the first, second, and third coils.

21. The apparatus of claim 1, wherein each lateral surface of the housing comprises a first edge width measured at a position where the lateral surface contacts the bottom surface, and a second edge width measured at an opening opposite to the position where the lateral surface contacts the bottom surface, and wherein the second edge width is larger than the first edge width.