Wireless charging station

• US 10,277,056 B2
• Filed: 06/16/2016
• Issued: 04/30/2019
• Est. Priority Date: 06/16/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Ritter, David W., Kosecoff, David B., Kumka, David S., Sampath, Madhusudanan Keezhveedi, Michalske, Steven Charles, Ashcroft, Tavys Q., Rao, Aditya, Smith, Ariadne
• Primary Examiner(s): Whitmore, Stacy
• Application Number:
  US15/184,868
• Publication Number:
  US 20160372960A1
• Time in Patent Office: 1,048 Days
• Field of Search: 320107
• CPC Class Codes: H01F 27/28 Coils; Windings; Conductive connections
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence

Abstract

A wireless charging system including a transmitter and a receiver. The transmitter is formed of a coil of wire that includes a first loop portion, a second loop portion, and a crossing portion. The crossing portion electrically couples the first loop portion and the second loop portion such that when current is generated in the coil, electrical current flows through the first loop portion in a different rotational direction than in the second loop portion. The receiver is formed of a ferromagnetic core and multiple (e.g., three) coils disposed about the ferromagnetic core. Each coil may be disposed about a different axis of the core such that current may be induced in at least one of the coils by a magnetic field in any direction.

Claims

1. A wireless charging transmitter comprising:

a coil configured to transmit power, the coil comprising;

a first loop portion coupled to a first node and a second node different from the first node, each node providing an avenue through which current can enter and exit out of the first loop portion of the coil;

a second loop portion coplanar with the first loop portion; and

a crossing portion comprising overlapping conductive paths that electrically couple the first loop portion and the second loop portion such that, when an electrical current is generated in the coil, the electrical current flows;

through the first loop portion in a first rotational direction; and

through the second loop portion in a second rotational direction opposite the first rotational direction.

2. The transmitter of claim 1 wherein the first loop portion and the second loop portion are characterized by substantially the same shape and dimensions.

3. The transmitter of claim 1 wherein when the electrical current is generated in the coil:

a first magnetic field is generated by the electrical current flowing through the first loop portion, the first magnetic field being characterized by a first direction; and

a second magnetic field is generated by the electrical current flowing through the second loop portion, the second magnetic field being characterized by a second direction different than the first direction.

4. The transmitter of claim 3 wherein the first direction and the second direction extend in opposite directions.

5. The transmitter of claim 1 wherein the coil is a first coil, wherein the crossing portion is a first crossing portion, and wherein the transmitter further comprises a second coil configured to transmit power, the second coil comprising:

a third loop portion;

a fourth loop portion; and

a second crossing portion comprising overlapping conductive paths that electrically couple the third loop portion and the fourth loop portion such that, when an electrical current is generated in the second coil, the electrical current flows;

through the third loop portion in the first rotational direction; and

through the fourth loop portion in the second rotational direction.

6. The transmitter of claim 5 wherein when the electrical current is generated in the first coil and the second coil, a bridging magnetic field is generated in a region between the first coil and the second coil.

7. The transmitter of claim 6 wherein the bridging magnetic field bends between the second loop portion and the third loop portion.

8. The transmitter of claim 5 wherein the second coil overlaps at least a portion of the first coil.

9. The transmitter of claim 1 wherein the first loop portion has a first horizontal part and a first vertical part, and the second loop portion has a second horizontal part and a second vertical part.

10. The transmitter of claim 9 wherein the first horizontal part extends above the second vertical part, and wherein the second horizontal part extends below the first vertical part.

11. A wireless charging system comprising:

a transmitter assembly comprising;

a charging surface; and

a plurality of transmitter coils disposed below the charging surface, each transmitter coil of the plurality of transmitter coils comprising;

a first loop portion coupled to a first node and a second node different from the first node, each node providing an avenue through which current can enter and exit out of the first loop portion of the coil;

a second loop portion coplanar with the first loop portion; and

a crossing portion comprising overlapping conductive paths that electrically couple the first loop portion and the second loop portion such that, when an electrical current is generated in the coil, the electrical current flows;

through the first loop portion in a first rotational direction; and

through the second loop portion in a second rotational direction opposite the first rotational direction;

a receiver assembly comprising;

a first coil disposed relative to a first axis;

a second coil disposed relative to a second axis, the second axis extending in a direction different than the first axis; and

a ferromagnetic structure positioned adjacent to the first coil and the second coil.

12. The wireless charging system of claim 11 further comprising a third receiver coil disposed relative to a third axis, the third axis being substantially perpendicular to the first axis and the second axis.

13. The wireless charging system of claim 11 wherein each transmitter coil has a length and a width, wherein the length is correlated with a dimension of the charging surface;

and wherein the plurality of coils comprises;

first and second transmitter coils configured to transmit power, the first coil generating first and second magnetic fields and the second coil generating third and fourth magnetic fields when driven with electrical current, the first and second transmitter coils forming a bridging magnetic field disposed between the first and second transmitter coils.