Apparatuses and related methods for detecting coil alignment with a wireless power receiver

• US 9,948,112 B2
• Filed: 09/26/2014
• Issued: 04/17/2018
• Est. Priority Date: 09/26/2014
• Status: Active Grant

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Inventors: Hao, Jianbin, Martchovsky, Detelin, Jeong, Chan Young, Naghavi, Arman
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Barnett, Joel
• Application Number:
  US14/499,009
• Publication Number:
  US 20160094043A1
• Time in Patent Office: 1,299 Days
• Field of Search: None
• 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 50/12 of the resonant type
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A wireless power receiver may include a receive coil configured to generate an AC power signal responsive to wireless power transfer from a wireless power transmitter, and control logic configured to detect misalignment of the receive coil and a transmit coil of the wireless power transmitter responsive to a determination of efficiency of wireless power transfer therebetween. A method for operating a wireless power receiver may include detecting misalignment between a receive coil and a transmit coil of a wireless power transmitter responsive to detecting monitoring a value indicative of efficiency of wireless power transfer between the wireless power transmitter and the wireless power receiver, and causing an indication to be provided to a user to assist with correcting the misalignment.

Claims

1. A wireless power enabled apparatus, comprising:

a wireless power receiver, including;

a receive coil configured to generate an AC power signal responsive to wireless power received from a wireless power transmitter; and

a control logic configured to;

determine an efficiency of wireless power transfer between a transmit coil and the receive coil; and

determine an amount of positional misalignment of the receive coil with respect to the transmit coil, when the receive coil is in a near field zone of the transmit coil, based at least on the determined efficiency.

2. The wireless power enabled apparatus of claim 1, wherein the control logic is configured to determine the efficiency of wireless power transfer based, at least in part, on determining an operating frequency of the AC power signal, and wherein the control logic is further configured to determine the amount of positional misalignment based at least in part on the operating frequency of the AC power signal.

3. The wireless power enabled apparatus of claim 2, wherein the control logic is configured to compare the operating frequency of the AC power signal with a look up table comprising positional misalignment amounts and corresponding operating frequencies.

4. The wireless power enabled apparatus of claim 3, wherein the look up table includes different entries of the operating frequencies adjusted for different operating conditions of the wireless power receiver.

5. The wireless power enabled apparatus of claim 4, wherein the different operating conditions include a load condition.

6. The wireless power enabled apparatus of claim 4, wherein the different operating conditions include an operational mode of a rectifier of the wireless power receiver.

7. The wireless power enabled apparatus of claim 6, wherein the operational mode of the rectifier includes one of a diode mode, half-synchronous mode, and full-synchronous mode.

8. The wireless power enabled apparatus of claim 4, wherein the different operating conditions include an operational mode of a voltage converter of the wireless power receiver.

9. The wireless power enabled apparatus of claim 8, wherein the operational mode of the voltage converter includes an input voltage level for the voltage converter.

10. The wireless power enabled apparatus of claim 1, wherein the control logic is further configured to provide an indication signal configured to indicate to a user a level of positional misalignment as either acceptable or unacceptable.

11. A wireless power enabled apparatus, comprising:

a wireless power receiver, including;

a receive coil configured to generate an AC power signal responsive to a wireless power signal; and

a control logic configured to;

determine an efficiency of wireless power transfer from a wireless power transmitter to the wireless power receiver; and

determine an amount of positional misalignment between the receive coil and a transmit coil of the wireless power transmitter, when the receive coil is in a near field zone of the transmit coil, based at least in part, on a comparison of a measured value with a reference value, the measured value indicative of the determined efficiency of wireless power transfer and the reference value indicative of an expected value of the efficiency of the wireless power transfer adjusted based on an operating condition of the wireless power receiver.

12. The wireless power enabled apparatus of claim 11, wherein the measured value and the reference value are power loss values.

13. The wireless power enabled apparatus of claim 11, wherein the measured value and the reference value are ratios of received power and transmitted power.

14. The wireless power enabled apparatus of claim 11, wherein data associated with the transmitted power is received by the control logic via communication with the wireless power transmitter.

15. The wireless power enabled apparatus of claim 11, wherein the measured value and the reference value are determined based on operating frequencies for the wireless power signal.

16. The wireless power enabled apparatus of claim 11, wherein the measured value and the reference value are determined based on voltages across the receive coil.

17. The wireless power enabled apparatus of claim 11, wherein the wireless power receiver further includes:

a rectifier and a voltage converter operably coupled with the receive coil to receive the AC power signal, wherein at least the reference value is adjusted for the operating condition that includes an operational mode of the rectifier and the voltage converter.

18. A method for operating a wireless power receiver, the method comprising:

determining a value indicative of an efficiency of wireless power transfer between a wireless power transmitter and the wireless power receiver;

determining an amount of positional misalignment between a receive coil of the wireless power receiver and a transmit coil of the wireless power transmitter, when the receive coil is in a near field zone of the transmit coil, based on the determined value; and

causing an indication of the amount of positional misalignment to be provided to a user to assist with correcting the positional misalignment.

19. The method of claim 18, wherein the determining the value indicative of the efficiency of wireless power transfer includes:

monitoring an operating frequency of a wireless power signal; and

comparing the operating frequency with reference operating frequencies, each reference frequency indicative of one of the efficiency of wireless power transfer or the amount of positional misalignment between the receive coil and the transmit coil, wherein the efficiency of wireless power transfer is adjusted based on an operating condition of the wireless power receiver.

20. The method of claim 18, wherein the causing the indication of the positional misalignment to be provided to the user to assist with correcting the positional misalignment includes providing the user with a level of misalignment from among a plurality of different levels of misalignment.