WIRELESS CHARGER CIRCUIT AND METHOD

• US 20140194160A1
• Filed: 01/04/2013
• Published: 07/10/2014
• Est. Priority Date: 01/04/2013
• Status: Active Grant

• Current Assignee: Silicon Spread Corporation
• Original Assignee: Silicon Spread Corporation
• Inventors: JING, Tao, REN, Chenxiao, GE, Yongmin
• Granted Patent: US 9,276,625 B2
• Time in Patent Office: Days
• US Class Current: 455/557
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H04B 1/3883 Arrangements for mounting batteries or battery chargers
• CPC Class Codes: H04M 1/0202 Portable telephone sets, e.g. cordless phones, mobile phones or bar type handsets constructional features of telephone transmitters or receivers, e.g. of speakers or microphones H04M1/03
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A charging system for a mobile device includes a transmitter and a receiver. The transmitter includes (a) a first interface to a power source; (b) a second interface to the receiver; (c) a polarity detection circuit for detecting polarities of the; and (d) first and second switches controlled by the polarity detection circuit, wherein each switch selectively connects a terminal of the first interface to a terminal of the second interface. The receiver includes: (a) a first interface; (b) a second interface coupled to a device to be charged; and (c) a connection circuit between a terminal of the first interface and a terminal of the second interface, wherein the connection circuit is conductive when the voltage across these terminals is of a first polarity, and a second polarity otherwise.

Claims

1. In a charging system for a mobile device including a transmitter and a receiver, the transmitter comprising:

a first interface to a power source having a first terminal and a second terminal;

a second interface to the receiver having a first terminal and a second terminal;

a polarity detection circuit coupled to the first and second terminals of the second interface for detecting polarities of the first and second terminals of the second interface; and

first and second switches controlled by the polarity detection circuit, wherein the first switch selectively connects the first terminal of the first interface to either the first terminal of the second interface or the second terminal of the second interface, and wherein the second switch selectively connects the first terminal of the first interface to either the first terminal of the second interface or the second terminal of the second interface.

2. The transmitter of claim 1, wherein the first and second terminals of the second interface are coupled to planar electrodes on a charging station for contacting charging terminals of a mobile device.

3. The transmitter of claim 1, further comprising:

a plurality of additional terminals in the second interface, and

a plurality of additional switches each selectively connecting one of the additional terminals to either the first terminal of the first interface or the second terminal of the first interface.

4. The transmitter of claim 1, further comprising a communication circuit for providing data over the first and second terminals of the second interface.

5. The transmitter of claim 4, further comprising a modulation circuit for modulating data for transmission to the receiver.

6. The transmitter of claim 4, further comprising a demodulation circuit for demodulating data received from the receiver.

7. The transmitter of claim 4, wherein the data comprises identification information received from the receiver.

8. The transmitter of claim 1, wherein the polarity circuit applies a voltage on one of the first and second terminals of the second interface and measures if a current at the other one of the first and second terminals of the second interface.

9. The transmitter of claim 1, further comprising a temperature sensing circuit.

10. The transmitter of claim 1, further comprising an over-current sensing circuit monitoring the currents in the first and second terminals of the second interface.

11. In a charging system for a mobile device including a transmitter and a receiver, the receiver comprising:

a first interface having a first terminal and a second terminal;

a second interface having a first terminal and a second terminal coupled to a device to be charged;

a connection circuit between the first terminal of the first interface and the first terminal of the second interface, wherein the connection circuit is conductive when the voltage across the first terminal of the first interface and the second terminal of the first interface is of a first polarity, and the connection circuit is non-conductive when the voltage across the first terminal of the first interface and the second terminal of the first interface is of a second polarity opposite the first polarity.

12. The receiver of claim 11, further comprises a diode connecting the first and second terminals of the second interface.

13. The receiver of claim 11, wherein the connection circuit comprises a zener diode.

14. The receiver of claim 11, wherein the connection circuit comprises a transistor.

15. The receiver of claim 14, further comprising current sensing circuit that senses the channel current in the transistor wherein, when the channel current exceeds a predetermined threshold, the current sensing circuit turns off the transistor.

16. The receiver of claim 15, wherein the current sensing circuit comprises a comparator that compares the voltage across the first terminal of the first interface and a voltage at the second terminal of the second interface.

17. The receiver of claim 11, further comprising a communication circuit for providing data over the first and second terminals of the first interface.

18. The receiver of claim 17, further comprising a modulation circuit for modulating data for transmission to the transmitter.

19. The receiver of claim 17, further comprising a demodulation circuit for demodulating data received from the transmitter.

20. The receiver of claim 11, wherein the receiver is provided a cover to be placed over the device to be charged.

21. The receiver of claim 20, wherein the device to be charged comprises a mobile communication device.

22. The receiver of claim 21, wherein the mobile communication device comprises a camera, wherein the first terminal of the first interface is provided as a conductive ring around the camera of the mobile communication device.

23. The receiver of claim 21, wherein the second terminal of the second interface comprises a conductive name plate.

24. The receiver of claim 21, wherein the cover further comprises a connector for coupling a power connector of the mobile communication device.

25. In a charging system for a mobile device including a transmitter and a receiver, a method for a transmitter comprising:

providing a first interface to a power source having a first terminal and a second terminal;

providing a second interface to the receiver having a first terminal and a second terminal;

detecting polarities of the first and second terminals of the second interface; and

controlling the first and second switches according to the detected polarities, wherein the first switch selectively connects the first terminal of the first interface to either the first terminal of the second interface or the second terminal of the second interface, and wherein the second switch selectively connects the first terminal of the first interface to either the first terminal of the second interface or the second terminal of the second interface.

26. The method of claim 25, further comprising connecting the first and second terminals of the second interface to planar electrodes on a charging station for contacting charging terminals of a mobile device.

27. The method of claim 25, further comprising:

providing a plurality of additional terminals in the second interface, and

providing a plurality of additional switches each selectively connecting one of the additional terminals to either the first terminal of the first interface or the second terminal of the first interface.

28. The method of claim 25, further comprising providing a communication circuit for providing data over the first and second terminals of the second interface.

29. The method of claim 28, wherein the data are provided after polarities on the first and second terminals of the first interface are detected.

30. The method of claim 28, further comprising providing a modulation circuit for modulating data for transmission to the receiver.

31. The method of claim 28, further comprising providing a demodulation circuit for demodulating data received from the receiver.

32. The method of claim 28, wherein the data comprises identification information received from the receiver.

33. The method of claim 25, further comprising initiating a charging operation after polarities of the first and second terminals of the first interface are detected.

34. The method of claim 25, further comprising applying a voltage on one of the first and second terminals of the second interface and measuring a current at the other one of the first and second terminals of the second interface.

35. The method of claim 25, further comprising sensing a temperature of the transmitter.

36. The method of claim 25, further comprising monitoring an over-current condition in the first and second terminals of the second interface.

37. In a charging system for a mobile device including a transmitter and a receiver, the method for a receiver comprising:

providing a first interface having a first terminal and a second terminal;

providing a second interface having a first terminal and a second terminal coupled to a device to be charged;

providing a connection circuit between the first terminal of the first interface and the first terminal of the second interface, wherein the connection circuit is conductive when the voltage across the first terminal of the first interface and the second terminal of the first interface is of a first polarity, and the connection circuit is non-conductive when the voltage across the first terminal of the first interface and the second terminal of the first interface is of a second polarity opposite the first polarity.

38. The method of claim 37, further comprises connecting a diode between the first and second terminals of the second interface.

39. The method of claim 37, wherein the connection circuit comprises a zener diode.

40. The method of claim 37, wherein the connection circuit comprises a transistor.

41. The method of claim 40, further comprising sensing the channel current in the transistor wherein, when the channel current exceeds a predetermined threshold, turning off the transistor.

42. The method of claim 41, wherein sensing the channel current comprises providing a comparator that compares the voltage across the first terminal of the first interface and a voltage at the second terminal of the second interface.

43. The method of claim 37, further comprising providing a communication circuit for providing data over the first and second terminals of the first interface.

44. The method of claim 37, further comprising providing a modulation circuit for modulating data for transmission to the transmitter.

45. The method of claim 37, further comprising providing a demodulation circuit for demodulating data received from the transmitter.

46. The method of claim 37, wherein the receiver is provided a cover to be placed over the device to be charged.

47. The method of claim 46, wherein the device to be charged comprises a mobile communication device.

48. The method of claim 47, wherein the mobile communication device comprises a camera, wherein the first terminal of the first interface is provided as a conductive ring around the camera of the mobile communication device.

49. The method of claim 47, wherein the second terminal of the second interface comprises a conductive name plate.

50. The method of claim 47, wherein the cover further comprises a connector for coupling a power connector of the mobile communication device.