WIRELESS CHARGER FOR CHARGING CONTROL AND CHARGING CONTROL METHOD THEREFOR

• US 20110115433A1
• Filed: 10/28/2010
• Published: 05/19/2011
• Est. Priority Date: 11/13/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Sung-Kweon, Lee, Woo-Ram, Park, Se-Ho, Kim, Ki-Hyun, Kim, Hong-Kweun
• Granted Patent: US 8,796,989 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• 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 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction

Abstract

A coil structure and a charging control method in a wireless charger having a primary coil are provided to supply an induced electromotive force suitable for a charging target having a secondary coil. Concentric coils having different radii are arranged in a wireless charger, and a coil suitable for the location of a charging target placed on the wireless charger is selected. An input power corresponding to the selected coil is determined, and the determined power is applied to the selected coil. Then the same charging efficiency can be provided irrespective of a location of a charging target placed on the wireless charger.

Claims

1. A charging control method in a wireless charger including a primary coil for performing charging through a secondary coil included in a charging target, the method comprising:

sensing whether the charging target is placed on the wireless charger, the wireless charger including one or more concentric coils having different radii;

checking the location on which the charging target is placed;

selecting a coil to be activated among the one or more coils according the checked location;

determining a power to be applied to the selected coil; and

supplying the determined power to the selected coil.

2. The charging control method of claim 1, wherein sensing whether the charging target is placed on the wireless charger comprises sensing the location of the charging target by a location sensor included in a touch pad, if the charging target is placed on the touch pad provided on one surface of the wireless charger.

3. The charging control method of claim 1, wherein selecting a coil to be activated comprises:

checking an area corresponding to a location where the charging target is placed among areas distinguished by the one or more coils; and

selecting a coil corresponding to the checked area.

4. The charging control method of claim 1, wherein the concentric coils having different radii have small numbers of turns as the radii thereof increase so as to generate the same inductance among the concentric coils.

5. The charging control method of claim 1, wherein determining power to be applied to the selected coil comprises determining the power according to a distance between the center of the one or more coils and the location of the charging target.

6. A wireless charger for charging control, including a primary coil for performing charging through a secondary coil included in a charging target, the wireless charger comprising:

one or more concentric coils having different radii;

a touch pad provided on one surface of the wireless charger;

a location sensor included in the touch pad, for sensing whether the charging target is placed on the touch pad and providing information about a location where the charging target is placed;

a controller for selecting a coil to be activated among the one or more coils according the location information provided by the location sensor; and

a power determiner for determining power to be applied to the selected coil and supplying the determined power to the selected coil.

7. The wireless charger of claim 6, wherein the one or more concentric coils having different radii have small numbers of turns as the radii thereof increase so as to generate the same inductance among the concentric coils.

9. The wireless charger of claim 6, wherein the one or more concentric coils are arranged in the wireless charger such that centers thereof are the same.

10. The wireless charger of claim 6, wherein the power determiner determines the power according to a distance between the center of the one or more coils and the location of the charging target.

11. The wireless charger of claim 6, further comprising:

an inverter for receiving the determined power from the power determiner and converting the determined power into a DC power; and

a switch connected to the one or more coils, for supplying the DC power to the selected coil.

12. The wireless charger of claim 6, wherein the controller checks an area corresponding to a location where the charging target is placed among areas distinguished by the one or more coils and selects a coil corresponding to the checked area.

8. The wireless charger of claim 8, wherein the one or more concentric coils are helical coils having a planar circular shape.