SYSTEMS AND METHODS FOR LIMITING VOLTAGE IN WIRELESS POWER RECEIVERS

• US 20130099585A1
• Filed: 09/18/2012
• Published: 04/25/2013
• Est. Priority Date: 10/21/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Von Novak, William H., Archambault, Joseph L., Tseng, Ryan, Wood, Adam J., Mayo, Gabriel Isaac, Kallal, Edward
• Granted Patent: US 9,508,487 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• 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: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/50 using additional energy repeaters between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

This disclosure provides systems, methods, and apparatus for the limiting of voltage in wireless power receivers. In one aspect, an apparatus includes a power transfer component configured to receive power wirelessly from a transmitter. The apparatus further includes a circuit coupled to the power transfer component and configured to reduce a received voltage when activated. The apparatus further includes a controller configured to activate the circuit when the received voltage reaches a first threshold value and configured to deactivate the circuit when the received voltage reaches a second threshold value. The apparatus further includes an antenna configured to generate a signal to the transmitter that signals to the transmitter that the received voltage reached the first threshold value.

Claims

1. An apparatus to receive power wirelessly from a transmitter, comprising:

a power transfer component configured to receive power wirelessly from the transmitter;

a circuit coupled to the power transfer component, the circuit configured to reduce a received voltage when activated;

a controller configured to activate the circuit when the received voltage reaches a first threshold value and configured to deactivate the circuit when the received voltage reaches a second threshold value; and

an antenna configured to generate a signal to the transmitter that signals to the transmitter that the received voltage reached the first threshold value.

2. The apparatus of claim 1, wherein the antenna is further configured to generate the signal when the circuit is activated.

3. The apparatus of claim 1, wherein the transmitter reduces a power level of the power transmitted to the power transfer component based on the signal received from the antenna that the received voltage reached the first threshold value.

4. The apparatus of claim 1, wherein the circuit is further configured to generate a pulse received by the transmitter when activated that signals to the transmitter that the received voltage reached the first threshold value.

5. The apparatus of claim 4, wherein the pulse is generated according to a pulse width modulation process.

6. The apparatus of claim 4, wherein the circuit is configured to generate a pulse at a first frequency that indicates to the transmitter that the received voltage reached the first threshold value, and wherein the first frequency is based on a frequency of the circuit and at least one capacitor.

7. The apparatus of claim 6, wherein the pulse is encoded by a change in an impedance of the power transfer component.

8. The apparatus of claim 4, wherein the controller is configured to activate a switch when the received voltage reaches the first threshold value to reduce the received voltage.

9. The apparatus of claim 8, wherein the controller is configured to deactivate the switch when the received voltage reaches the second threshold value.

10. The apparatus of claim 8, wherein the switch is configured to generate a pulse received by the transmitter, wherein the transmitter determines whether the received voltage reached the first threshold value based on the received pulse, and wherein an output of the pulse generated by the switch is based on whether the received voltage reached the first threshold value.

11. The apparatus of claim 10, wherein an output of the pulse is inverted if the received voltage reached the first threshold value.

12. The apparatus of claim 10, wherein an output of the pulse is non-inverted if the received voltage reached the second threshold value.

13. The apparatus of claim 1, wherein the first threshold value is less than a maximum voltage necessary to operate the apparatus in a steady state.

14. The apparatus of claim 1, wherein the second threshold value is greater than a minimum voltage necessary to operate the apparatus in a steady state.

15. A method for limiting voltage in a wireless power receiver, the method comprising:

receiving power wirelessly from a transmitter;

measuring a value of a received voltage;

activating a circuit when the received voltage reaches a first threshold value, the circuit configured to reduce the received voltage;

generating a pulse received by the transmitter when the circuit is activated that signals to the transmitter that the received voltage reached the first threshold value; and

deactivating the circuit when the received voltage reaches a second threshold value.

16. The method of claim 15, wherein generating a pulse comprises signaling to the transmitter a message that causes the transmitter to reduce a power level of the power transmitted to the wireless power receiver.

17. The method of claim 15, wherein generating a pulse comprises generating the pulse according to a pulse width modulation process.

18. The method of claim 15, wherein generating a pulse comprises generating a pulse at a first frequency that indicates to the transmitter that the received voltage reached the first threshold value, wherein the first frequency is based on a frequency of the circuit and at least one capacitor.

19. The method of claim 18, further comprising encoding the pulse based on a change in an impedance of the wireless power receiver.

20. The method of claim 15, wherein activating a circuit comprises activating a switch when the received voltage reaches the first threshold value to reduce the received voltage.

21. The method of claim 20, wherein deactivating a circuit comprises deactivating the switch when the received voltage reaches the second threshold value.

22. The method of claim 20, wherein generating a pulse received by the transmitter comprises generating the pulse by the switch, wherein the transmitter determines whether the received voltage reached the first threshold value based on the received pulse, and wherein an output of the generated pulse is based on whether the received voltage reached the first threshold value.

23. The method of claim 22, wherein an output of the pulse is inverted if the received voltage reached the first threshold value.

24. The method of claim 22, wherein an output of the pulse is non-inverted if the received voltage reached the second threshold value.

25. The method of claim 15, wherein activating the circuit comprises activating the circuit when the received voltage is less than a maximum voltage necessary to operate the wireless power receiver in a steady state.

26. The method of claim 15, wherein deactivating the circuit comprises deactivating the circuit when the received voltage is greater than a minimum voltage necessary to operate the wireless power receiver in a steady state.

27. The method of claim 15, wherein generating a pulse received by the transmitter comprises generating the pulse for transmission via an antenna coupled to the circuit, wherein the antenna does not receive power wirelessly from the transmitter.

28. An apparatus configured to limit voltage in a wireless power receiver, the apparatus comprising:

means for receiving power wirelessly from a transmitter;

means for measuring a value of a received voltage;

means for activating a circuit when the received voltage reaches a first threshold value, the circuit configured to reduce the received voltage;

means for generating a pulse received by the transmitter when the circuit is activated that signals to the transmitter that the received voltage reached the first threshold value; and

means for deactivating the circuit when the received voltage reaches a second threshold value.

29. The apparatus of claim 28, wherein means for generating a pulse comprises means for signaling to the transmitter a message that causes the transmitter to reduce a power level of the power transmitted to the wireless power receiver.

30. The apparatus of claim 28, wherein means for generating a pulse comprises means for generating the pulse according to a pulse width modulation process.

31. The apparatus of claim 28, wherein means for generating a pulse comprises means for generating a pulse at a first frequency that indicates to the transmitter that the received voltage reached the first threshold value, wherein the first frequency is based on a frequency of the circuit and at least one capacitor.

32. The apparatus of claim 31, further comprising means for encoding the pulse based on a change in an impedance of the wireless power receiver.

33. The apparatus of claim 28, wherein means for activating a circuit comprises means for activating a switch when the received voltage reaches the first threshold value to reduce the received voltage.

34. The apparatus of claim 33, wherein means for deactivating a circuit comprises means for deactivating the switch when the received voltage reaches the second threshold value.

35. The apparatus of claim 33, wherein means for generating a pulse received by the transmitter comprises means for generating the pulse by the switch, wherein the transmitter determines whether the received voltage reached the first threshold value based on the received pulse, and wherein an output of the generated pulse is based on whether the received voltage reached the first threshold value.

36. The apparatus of claim 35, wherein an output of the pulse is inverted if the received voltage reached the first threshold value.

37. The apparatus of claim 35, wherein an output of the pulse is non-inverted if the received voltage reached the second threshold value.

38. The apparatus of claim 28, wherein means for activating the circuit comprises means for activating the circuit when the received voltage is less than a maximum voltage necessary to operate the wireless power receiver in a steady state.

39. The apparatus of claim 28, wherein means for deactivating the circuit comprises means for deactivating the circuit when the received voltage is greater than a minimum voltage necessary to operate the wireless power receiver in a steady state.

40. The apparatus of claim 28, wherein the means for receiving comprises a receive coil, wherein the means for measuring, the means for activating, and the means for deactivating comprise a controller, and wherein the means for generating comprises a switch.

41. The apparatus of claim 28, wherein the means for receiving comprises a receive coil and the means for generating comprises an antenna.

42. A non-transitory computer-readable medium comprising code that, when executed, causes an apparatus to:

receive power wirelessly from a transmitter;

measure a value of a received voltage;

activate a circuit when the received voltage reaches a first threshold value, the circuit configured to reduce the received voltage;

generate a pulse received by the transmitter when the circuit is activated that signals to the transmitter that the received voltage reached the first threshold value; and

deactivate the circuit when the received voltage reaches a second threshold value.

43. The medium of claim 42, further comprising code that, when executed, causes the apparatus to signal to the transmitter a message that causes the transmitter to reduce a power level of the power transmitted to the wireless power receiver.

44. The medium of claim 42, further comprising code that, when executed, causes the apparatus to generate the pulse according to a pulse width modulation process.

45. The medium of claim 42, further comprising code that, when executed, causes the apparatus to generate a pulse at a first frequency that indicates to the transmitter that the received voltage reached the first threshold value, wherein the first frequency is based on a frequency of the circuit and at least one capacitor.

46. The medium of claim 45, further comprising code that, when executed, causes the apparatus to encoding the pulse based on a change in an impedance of the apparatus.

47. The medium of claim 42, further comprising code that, when executed, causes the apparatus to activate a switch when the received voltage reaches the first threshold value to reduce the received voltage.

48. The medium of claim 47, further comprising code that, when executed, causes the apparatus to deactivate the switch when the received voltage reaches the second threshold value.

49. The medium of claim 47, further comprising code that, when executed, causes the apparatus to generate the pulse by the switch, wherein the transmitter determines whether the received voltage reached the first threshold value based on the received pulse, and wherein an output of the generated pulse is based on whether the received voltage reached the first threshold value.

50. The medium of claim 49, wherein an output of the pulse is inverted if the received voltage reached the first threshold value.

51. The medium of claim 49, wherein an output of the pulse is non-inverted if the received voltage reached the second threshold value.

52. The medium of claim 43, further comprising code that, when executed, causes the apparatus to activate the circuit when the received voltage is less than a maximum voltage necessary to operate the wireless power receiver in a steady state.

53. The medium of claim 43, further comprising code that, when executed, causes the apparatus to deactivate the circuit when the received voltage is greater than a minimum voltage necessary to operate the wireless power receiver in a steady state.

54. The medium of claim 42, further comprising code that, when executed, causes the apparatus to generate the pulse for transmission via an antenna coupled to the circuit, wherein the antenna does not receive power wirelessly from the transmitter.

55. A method for limiting voltage in a wireless power receiver, the method comprising:

receiving power wirelessly from a transmitter;

measuring a value of a received voltage;

activating a circuit when the received voltage reaches a first threshold value to reduce the received voltage;

generating a pulse received by the transmitter when the circuit is activated that signals to the transmitter that the received voltage reached the first threshold value; and

deactivating the circuit after a fixed time.