ADJUSTING FILTER IN A COUPLED COIL SYSTEM

• US 20150244179A1
• Filed: 02/20/2015
• Published: 08/27/2015
• Est. Priority Date: 02/23/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Ritter, David W., Alves, Jeffrey M., Moyer, Todd K., Herbst, Steven G.
• Granted Patent: US 9,923,383 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance

Abstract

A receiver device in a coupled coil system for wireless energy transfer includes a receiver coil and a load device operatively connected to the receiver coil and configured to receive a signal from the receiver coil. As one example, the load device is a rechargeable battery. An adjusting filter is included in the receiver device and is operatively connected between the receiver coil and the load device. The adjusting filter can be used to transform the effective resistance or impedance of the load as presented to the transformer during energy transfer so that the effective resistant or impedance of the load is maintained at a substantially constant level, and the signal received by the load device is maintained at a substantially constant level.

Claims

1. A receiver device configured for wireless energy transfer, the receiver device comprising:

a receiver coil;

a load device operatively connected to the receiver coil; and

an adjusting filter operatively connected between the receiver coil and the load device, wherein the adjusting filter adjusts a signal received from the receiver coil to adjust an effective resistance or impedance of a load of the receiver device.

2. The receiver device as in claim 1, further comprising a rectifier operatively connected between the adjusting filter and the load device.

3. The receiver device as in claim 1, wherein the adjusting filter comprises a linear adjusting filter.

4. The receiver device as in claim 3, wherein the adjusting filter comprises:

a first capacitor connected in series to the receiver coil; and

a second capacitor connected in parallel with the receiver coil.

5. The receiver device as in claim 1, wherein the adjusting filter comprises a non-linear adjusting filter.

6. The receiver device as in claim 2, wherein the adjusting filter comprises a non-linear adjusting filter.

7. The receiver device as in claim 6, wherein the rectifier comprises four diodes arranged in a bridge circuit.

8. The receiver device as in claim 7, wherein the non-linear adjusting filter comprises:

a first capacitor connected in series to the receiver coil; and

a second capacitor connected in parallel with a grounded diode in the rectifier.

9. The receiver device as in claim 1, wherein the load device comprises a rechargeable battery.

10. The receiver device as in claim 1, wherein the receiver device comprises a portable electronic device.

11. The receiver device as in claim 1, wherein the adjusting filter comprises a programmable adjusting filter.

12. The receiver device as in claim 11, wherein the programmable adjusting filter comprises a first variable capacitor connected in series with the receiver coil and a second variable capacitor connected in parallel with the receiver coil.

13. The receiver device as in claim 2, wherein the rectifier comprises four diodes arranged in a bridge circuit.

14. The receiver device as in claim 13, wherein the adjusting filter comprises a programmable adjusting filter.

15. The receiver device as in claim 14, wherein the programmable adjusting filter comprises a first variable capacitor connected in series with the receiver coil and a second variable capacitor connected in parallel with a grounded diode in the rectifier.

16. A method for wirelessly transferring energy from a transmitter coil in a transmitter device to a receiver coil in a receiver device, the method comprising:

determining one or more operating parameters of a load device in the receiver device operatively connected to the receiver coil and configured to receive a signal from the receiver coil;

determining a frequency of a signal applied to the transmitter coil in the transmitter device; and

setting a capacitance value for at least one variable capacitor in a programmable adjusting filter operatively connected to the receiver coil based on the one or more operating parameters of the load device and the frequency of the signal.

17. The method as in claim 16, wherein the one or more operating parameters comprises a current.

18. The method as in claim 16, wherein the one or more operating parameters comprises a voltage.

19. The method as in claim 16, wherein setting the capacitance value for at least one variable capacitor in the programmable adjusting filter operatively connected to the receiver coil comprises setting a first capacitance value for a first variable capacitor connected in series with the receiver coil and setting a second capacitance value for a second variable capacitor connected in parallel with the receiver coil.

20. The method as in claim 16, wherein the transmitter device comprises a charging device.

21. The method as in claim 16, wherein the receiver device comprises a portable electronic device.

22. A method for wirelessly transferring energy from a transmitter coil in a transmitter device to a receiver coil in a receiver device, the method comprising:

transferring energy to the receiver coil by applying a signal to the transmitter coil when a battery operatively connected to the receiver coil is in an operating mode;

adjusting a signal received from the receiver coil;

inputting the adjusted signal into the battery; and

shifting a frequency of the signal applied to the transmitter coil based on a change in the operating mode of the battery.

23. The method as in claim 22, wherein the transmitter device comprises a charging device.

24. The method as in claim 22, wherein the receiver device comprises a portable electronic device.

25. The method as in claim 22, wherein adjusting the signal received from the receiver coil comprises increasing a signal received from the receiver coil.

26. The method as in claim 22, wherein adjusting the signal received from the receiver coil comprises decreasing a signal received from the receiver coil.

27. A method for wirelessly transferring energy from a transmitter coil in a transmitter device to a receiver coil in a receiver device, the method comprising:

determining one or more operating parameters of a load device in the receiver device operatively connected to the receiver coil and configured to receive a signal from the receiver coil;

determining a frequency of a signal applied to the transmitter coil in the transmitter device; and

setting a component value for at least one variable component in a programmable adjusting filter operatively connected to the receiver coil based on the one or more operating parameters of the load device and the frequency of the signal.

28. The method as in claim 27, wherein the one or more operating parameters comprises a current.

29. The method as in claim 27, wherein the one or more operating parameters comprises a voltage.

30. The method as in claim 27, wherein setting a component value for at least one variable component in a programmable adjusting filter operatively connected to the receiver coil comprises setting a first capacitance value for a first variable capacitor connected in series with the receiver coil and setting a second capacitance value for a second variable capacitor connected in parallel with the receiver coil.