Wireless charger circuit and method

• US 9,276,625 B2
• Filed: 01/04/2013
• Issued: 03/01/2016
• Est. Priority Date: 01/04/2013
• Status: Expired due to Fees

• Current Assignee: Silicon Spread Corporation
• Original Assignee: Silicon Spread Corporation
• Inventors: Jing, Tao, Ren, Chenxiao, Ge, Yongmin
• Primary Examiner(s): Nguyen, Lee
• Application Number:
  US13/734,610
• Publication Number:
  US 20140194160A1
• Time in Patent Office: 1,152 Days
• Field of Search: 455/127.1, 455/572, 455/573, 320/165
• US Class Current: 1/1
• 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, the polarity detection circuit detecting the polarities based on measurements made upon (a) imposing a positive voltage across the first and second terminals of the second interface during a first time period and (b) imposing a negative voltage across the first and second terminals of the second interface during a second time period;

a current sensing circuit; and

first and second switches controlled by the polarity detection circuit, wherein the polarity detection circuit causes (i) the first switch selectively connect 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 (ii) the second switch to selectively connect the second terminal of the first interface to either the first terminal of the second interface or the second terminal of the second interface, and wherein, when the terminals of the first and second interfaces are connected by the first and second switches, the current sensing circuit monitors charging currents in real time in the first and second terminals 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 the positive voltage on one of the first and second terminals of the second interface and measures if a current flows out of 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, wherein the current sensing circuit further comprises an over-current sensing circuit monitoring an over-current condition 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, 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 based on measurements made upon (a) imposing a positive voltage across the first and second terminals of the second interface during a first time period and (b) imposing a negative voltage across the first and second terminals of the second interface during a second time period;

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 second terminal of the first interface to either the first terminal of the second interface or the second terminal of the second interface; and

upon the terminals of the first and second interfaces are connected, monitoring charging currents in real time in the first and second terminals of the second interface.

12. The method of claim 11, 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.

13. The method of claim 11, 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.

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

15. The method of claim 14, wherein the data are provided after polarities on the first and second terminals of the first interface are detected.

16. The method of claim 14, further comprising providing a modulation circuit for modulating data for transmission to the receiver.

17. The method of claim 14, further comprising providing a demodulation circuit for demodulating data received from the receiver.

18. The method of claim 14, wherein the data comprises identification information received from the receiver.

19. The method of claim 11, further comprising initiating a charging operation after polarities of the first and second terminals of the first interface are detected.

20. The method of claim 11, wherein the positive voltage is applied 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.

21. The method of claim 11, further comprising sensing a temperature of the transmitter.

22. The method of claim 11, further comprising monitoring an over-current condition in the first and second terminals of the second interface.