WIRELESS POWER RECEIVER AND METHOD FOR CONTROLLING THE SAME

• US 20120293008A1
• Filed: 05/16/2012
• Published: 11/22/2012
• Est. Priority Date: 05/17/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: PARK, Sung-Kweon, Kim, Ki-Hyun, Ko, Kil-Soo, Park, Se-Ho, Park, Jin-Hyoung
• Granted Patent: US 9,780,568 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/10 using inductive coupling
• 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 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H02M 1/14 Arrangements for reducing ripples from dc input or output

Abstract

A wireless power receiver that receives wireless power from a wireless power transmitter and a control method thereof are provided, wherein the wireless power receiver receives the wireless power from the wireless power transmitter; rectifies the wireless power; monitoring a voltage value of the rectified wireless power; determines whether a ripple of the voltage value of the wireless power is greater than or equal to a preset threshold; and if the ripple of the voltage value of the wireless power is greater than or equal to the preset threshold, changes at least one element value of the wireless power receiver to suppress the ripple below the preset threshold.

Claims

1. A control method in a wireless power receiver that receives wireless power from a wireless power transmitter, the method comprising:

receiving the wireless power from the wireless power transmitter;

rectifying the wireless power;

monitoring a voltage value of the rectified wireless power;

determining whether a ripple of the voltage value of the rectified wireless power is greater than or equal to a preset threshold; and

if the ripple of the voltage value of the wireless power is greater than or equal to the preset threshold, changing at least one element value of the wireless power receiver to suppress the ripple below the preset threshold.

2. The control method of claim 1, further comprising outputting the rectified wireless power in a form of Direct Current (DC)

3. The control method of claim 1, further comprising modulating the rectified wireless power.

4. The control method of claim 3, wherein the rectified wireless power is modulated based on a resistive load modulation scheme.

5. The control method of claim 3, wherein the rectified wireless power is modulated based on a capacitive load modulation scheme.

6. The control method of claim 1, wherein changing the at least one element value comprises changing a resistance of a variable resistor.

7. The control method of claim 1, wherein changing the at least one element value comprises changing a capacitance of a variable capacitor.

8. The control method of claim 1, wherein changing the at least one element value comprises repeatedly changing the at least one element value by a preset value until the ripple falls below the preset threshold.

9. The control method of claim 1, wherein changing the at least one element value comprises:

calculating a difference between an absolute value of the ripple and an absolute value of a proper ripple;

reading a look-up table for a relationship between the difference and a change in element value, which corresponds to the difference; and

changing the at least one element value by the read change in the element value.

10. A wireless power receiver for receiving wireless power from a wireless power transmitter, comprising:

a power receiver for receiving the wireless power from the wireless power transmitter;

a rectifier for rectifying the wireless power;

a controller for monitoring a voltage value of the rectified wireless power, determining whether a ripple of the voltage value of the rectified wireless power is greater than or equal to a preset threshold, and if the ripple of the voltage value of the wireless power is greater than or equal to a preset threshold, changing at least one element value of the wireless power receiver to suppress the ripple below the preset threshold; and

a charger for charging the rectified wireless power.

11. The wireless power receiver of claim 10, wherein the controller outputs the rectified wireless power in a form of Direct Current (DC).

12. The wireless power receiver of claim 10, further comprising a modulator for modulating the rectified wireless power.

13. The wireless power receiver of claim 12, wherein the modulator modulates the rectified wireless power based on a resistive load modulation scheme, and includes a variable resistor.

14. The wireless power receiver of claim 13, wherein the controller changes a resistance of the variable resistor to suppress the ripple below the preset threshold.

15. The wireless power receiver of claim 12, wherein the modulator modulates the rectified wireless power based on a capacitive load modulation, and includes a variable capacitor.

16. The wireless power receiver of claim 15, wherein the controller changes a capacitance of the variable capacitor to suppress the ripple below the preset threshold.

17. The wireless power receiver of claim 10, wherein the controller repeatedly changes the at least one element value by a preset value, until the ripple is below the preset threshold.

18. The wireless power receiver of claim 10, further comprising a storage for storing a look-up table including a relationship between an absolute value of a proper ripple and a change in element value that corresponds to a difference between an absolute value of a ripple and the absolute value of the proper ripple,

wherein the controller calculates the difference between the absolute value of the ripple and the absolute value of the proper ripple, reads the look-up table for the relationship between the difference and the change in element value, which corresponds to the difference, and changes the at least one element value by the read change in the element value.

19. The wireless power receiver of claim 12, wherein the modulator comprises:

a first resistor having a first end connected to the rectifier and a second end connected to the controller;

a second resistor having a first end connected to the controller and the second end of the first resistor, and a second end connected to the rectifier;

a variable resistor having a first end connected to the first resistor and a second end connected to the controller; and

a switch having a first end connected to the second end of the variable resistor and a second end connected to the charger.

20. The wireless power receiver of claim 19, wherein the switch includes an N-channel Metal-Oxide-Semiconductor (N-MOS) element, a gate of which is connected to the controller.