Wireless charger for charging control and charging control method therefor

• US 8,796,989 B2
• Filed: 10/28/2010
• Issued: 08/05/2014
• Est. Priority Date: 11/13/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Woo-Ram, Park, Sung-Kweon, Kim, Ki-Hyun, Kim, Hong-Kweun, Park, Se-Ho
• Primary Examiner(s): Dunn, Drew A
• Assistant Examiner(s): DIBENEDETTO, MICHAEL N
• Application Number:
  US12/914,028
• Publication Number:
  US 20110115433A1
• Time in Patent Office: 1,377 Days
• Field of Search: 320/108, 307/150
• 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 a plurality of flat spiral concentric coils having different radii;

checking a location on which the charging target is placed;

selecting a coil to be activated from among the plurality of coils according the checked location;

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

supplying the determined power to the selected coil,

wherein the plurality of flat spiral concentric coils having different radii have smaller numbers of turns as the radii thereof increase so as to generate the same inductance among the flat spiral concentric coils.

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 the coil to be activated comprises:

checking an area corresponding to the location where the charging target is placed among areas distinguished by the plurality of coils; and

selecting a coil corresponding to the checked area.

4. 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 plurality of coils and the location of the charging target.

5. 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:

a plurality of flat spiral 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 plurality of 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,

wherein the plurality of flat spiral concentric coils having different radii have smaller numbers of turns as the radii thereof increase so as to generate the same inductance among the plurality of flat spiral concentric coils.

6. The wireless charger of claim 5, wherein the location sensor is a pressure sensor.

7. The wireless charger of claim 5, wherein the power determiner determines the power according to a distance between the center of the plurality of coils and the location of the charging target.

8. The wireless charger of claim 5, further comprising:

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

a switch connected to the plurality of coils, for supplying the AC power to the selected coil.

9. The wireless charger of claim 5, wherein the controller checks an area corresponding to a location where the charging target is placed among areas distinguished by the plurality of coils and selects a coil corresponding to the checked area.