Transmitter for inductive power transfer systems

• US 10,396,596 B2
• Filed: 11/07/2014
• Issued: 08/27/2019
• Est. Priority Date: 11/13/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Abdolkhani, Ali, Hu, Aiguo, Wang, Ya-Ting, Kumar, Arunim
• Primary Examiner(s): Pacheco, Alexis B
• Application Number:
  US15/036,656
• Publication Number:
  US 20160308394A1
• Time in Patent Office: 1,754 Days
• Field of Search: 320107, 320108, 320109, 320113, 320114, 320115, 320116, 320134
• 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 7/0042 characterised by the mechanical construction
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

An inductive power transmitter having a plurality of transmitting coils for generating an alternating magnetic field arranged in a row with each transmitting coil partially overlapping with adjacent transmitting coils in the row. A transmitting circuit connected to each transmitting coil may drive the transmitting coils so that each transmitting coil'"'"'s alternating magnetic field is phase shifted with respect to the alternating magnetic field of adjacent transmitting coils in the row or so that the alternating magnetic field generated by the transmitting coils travels along a charging surface.

Claims

1. An inductive power transmitter comprising:

a plurality of transmitting coils configured to generate an alternating magnetic field, wherein each transmitting coil in the plurality of transmitting coils partially overlaps at least one other transmitting coil in the plurality of transmitting coils and wherein the transmitting coils in the plurality of transmitting coils are spatially offset in at least two dimensions with respect to each other; and

transmitting circuitry coupled to each of the transmitting coils in the plurality of transmitting coils, wherein the transmitting circuitry is configured to drive the plurality of transmitting coils with a phase shift between adjacent transmitting coils in the plurality of transmitting coils, and wherein the alternating magnetic field generated by the plurality of transmitting coils travels along a surface of the inductive power transmitter.

2. The inductive power transmitter of claim 1, wherein the inductive power transmitter includes a magnetically permeable layer.

3. The inductive power transmitter of claim 1, wherein the plurality of transmitting coils are arranged in a row and there is only one row of transmitting coils in the inductive power transmitter.

4. The inductive power transmitter of claim 1, wherein the plurality of transmitting coils are arranged in a row and there are at least two rows of transmitting coils in the inductive power transmitter.

5. The inductive power transmitter of claim 1, wherein the transmitting coils in the plurality of transmitting coils are arranged in a row with a regular distribution.

6. The inductive power transmitter of claim 1, wherein the plurality of transmitting coils are arranged in a row and each transmitting coil in the row partially overlaps all other transmitting coils in the row.

7. The inductive power transmitter of claim 1, wherein the plurality of transmitting coils are arranged in a row and each transmitting coil in the row is the same size.

8. The inductive power transmitter of claim 1, wherein the plurality of transmitting coils are arranged in a row and each transmitting coil in the row is defined by a transmitting coil width parallel to a direction of the row and a transmitting coil length perpendicular to the direction of the row.

9. The inductive power transmitter of claim 8, wherein each transmitting coil in the row partially overlaps an immediately adjacent transmitting coil in the row by (n−

1)/n of the transmitting coil width, where n is the number of transmitting coils in the row.

10. The inductive power transmitter of claim 1, wherein the inductive power transmitter is incorporated into a charging mat having a charging surface.

11. The inductive power transmitter of claim 10, wherein the transmitting coils in the plurality of transmitting coils are coplanar with the charging surface.

12. The inductive power transmitter of claim 10, wherein the charging surface is defined by a charging surface length and a charging surface width.

13. The inductive power transmitter of claim 12, wherein the plurality of transmitting coils are arranged in a row and each transmitting coil in the row is defined by a transmitting coil width parallel to a direction of the row and a transmitting coil length perpendicular to the direction of the row.

14. The inductive power transmitter of claim 13, wherein the transmitting coil length is the same as the charging surface width.

15. The inductive power transmitter of claim 13, wherein the transmitting coil width is n/(2n−

1) of the charging surface length, where n is the number of transmitting coils in the row.

16. The inductive power transmitter of claim 1, wherein each transmitting coil in the plurality of transmitting coils is coupled to a resonant capacitor to create a resonant circuit.

17. The inductive power transmitter of claim 16, wherein each transmitting coil in the plurality of transmitting coils is coupled in parallel to the resonant capacitor.

18. The inductive power transmitter of claim 16, wherein each transmitting coil in the plurality of transmitting coils is coupled in series to the resonant capacitor.

19. The inductive power transmitter of claim 1, wherein each transmitting coil in the plurality of transmitting coils produces an alternating magnetic field that is phase shifted with respect to an alternating magnetic field produced by an immediately adjacent transmitting coil in the plurality of transmitting coils by 180/n degrees, where n is the total number of transmitting coils in the inductive power transmitter.

20. The inductive power transmitter of claim 1, wherein each transmitting coil in the plurality of transmitting coils is coupled to separate transmitting circuitry.

21. The inductive power transmitter of claim 1, wherein the transmitting circuitry comprises a single transmitting circuit shared by all of the transmitting coils in the plurality of transmitting coils and wherein the single transmitting circuit is adapted to generate a multiphase signal.

22. The inductive power transmitter of claim 1, wherein the plurality of transmitting coils comprises three transmitting coils arranged in a row.