WIRELESS CHARGING SYSTEM

• US 20130082650A1
• Filed: 09/25/2012
• Published: 04/04/2013
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: Wit Co., Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Lee, Hyun Seok, Yoon, Jeong Ho, Min, Jun Ki, Lee, Kwang Du
• Granted Patent: US 9,419,464 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

Disclosed herein is a wireless charging system that includes a transmission device including a primary coil and a reception device including a secondary coil, wherein the transmission device determines the presence or absence of the reception device upon receiving the remaining amount of current supplied from the primary coil to the secondary coil, and controls a voltage input to the primary coil based on the determination results. The wireless charging system can generate a sensing signal for determining the presence and absence of the reception device by measuring the amount of current applied from the transmitter coil to the receiver coil through the detection unit. Thus, the receiver controller of the wireless charging system can accurately determine whether to transmit power by comparing the sensing signal provided from the detection unit with a reference signal, thus reducing power consumption.

Claims

1. A wireless charging system that includes a transmission device including a primary coil and a reception device including a secondary coil,

wherein the transmission device determines the presence or absence of the reception device upon receiving a feedback remaining amount of a current supplied from the primary coil to the secondary coil, and controls a voltage input to the primary coil based on the determination results.

2. The wireless charging system according to claim 1, wherein the transmission device includes:

a detection unit generating a sensing signal for determining the presence or absence of the reception device upon receiving the feedback remaining amount of a current; and

a transmitter controller comparing the sensing signal supplied from the detection unit with a pre-set comparison signal, and generating a control signal for determining the level of a voltage input to the primary coil based on the comparison results.

3. The wireless charging system according to claim 2, wherein when the remaining amount of current is gradually reduced, the detection unit generates the sensing signal indicating that the reception device is present.

4. The wireless charging system according to claim 2, wherein when the remaining amount of current is gradually increased, the detection unit generates the sensing signal indicating that the reception device is not present.

5. A wireless charging system that includes a transmission device including a primary coil and a reception device including a secondary coil,

wherein the transmission device includes:

a power source unit generating charging power by using an external power source;

a power amplifier (PA) driving unit amplifying a high frequency from the charging power generated by the power source unit;

a detection unit electrically connected with the primary coil and generating a sensing signal upon receiving a feedback remaining amount of a current supplied from the primary coil to the secondary coil; and

a controller comparing the sensing signal provided from the detection unit with a reference signal and generating a control signal for driving the PA driving unit based on the comparison results.

6. The wireless charging system according to claim 5, wherein the detection unit includes:

an isolation unit preventing interference with main power when the remaining amount of current is fed back from the primary coil;

a sensing unit having one end connected with the isolation unit and sensing the remaining amount of current supplied from the isolation unit to generate a measurement signal;

a comparison unit comparing an input signal provided from the isolation unit with the measurement signal provided from the sensing unit to generate a comparison signal; and

a calculation unit digitalizing the comparison signal output from the comparison unit to generate the sensing signal.

7. The wireless charging system according to claim 6, wherein the isolation unit is a transformer.

8. The wireless charging system according to claim 6, wherein the sensing unit is configured as a resistor, and one end of the resistor is connected with the isolation unit and the other end of the resistor is connected with any one of the input terminals of the comparison unit.

9. The wireless charging system according to claim 6, wherein when the remaining amount of current is gradually reduced, the detection unit generates the sensing signal indicating that the reception device is present.

10. The wireless charging system according to claim 6, wherein when the remaining amount of current is gradually increased, the detection unit generates the sensing signal indicating that the reception device is not present.

11. The wireless charging system according to claim 5, wherein when the sensing signal is smaller than the reference signal, the controller recognizes that the reception device is present, and generates the control signal for activating the PA driving unit.

12. The wireless charging system according to claim 5, wherein when the sensing signal is greater than the reference signal, the controller recognizes that the reception device is not present, and generates the control signal for deactivating the PA driving unit.

13. A charging method of a wireless charging system including a transmission device including a primary coil and a reception device including a secondary coil, the method comprising:

generating a sensing signal upon receiving a feedback remaining amount of a current supplied from the primary coil to the secondary coil and;

comparing the sensing signal with a pre-set reference signal; and

controlling a voltage input to the primary coil based on the comparison results.

14. The method according to claim 13, wherein, in generating of the sensing signal, when the remaining amount of current is gradually reduced, the sensing signal indicating that the reception device is present is generated.

15. The method according to claim 13, wherein, in generating of the sensing signal, when the remaining amount of current is gradually increased, the sensing signal indicating that the reception device is not present is generated.

16. The method according to claim 13, wherein, in comparing of the sensing signal, when the sensing signal is smaller than the reference signal, the presence of the reception device is recognized and the control signal for activating the PA driving unit is generated.

17. The method according to claim 13, wherein, in comparing of the sensing signal, when the sensing signal is greater than the reference signal, the absence of the reception device is recognized and the control signal for deactivating the PA driving unit is generated.

18. The method according to claim 13, wherein the comparison signal is a signal, which is generated in the transmission device in a state in which the reception device is not present, stored as a default value.