Wireless charging system

• US 9,419,464 B2
• Filed: 09/25/2012
• Issued: 08/16/2016
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: Wit Co., Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Yoon, Jeong Ho, Lee, Hyun Seok, Min, Jun Ki, Lee, Kwang Du
• Primary Examiner(s): Alam, Mohammed
• Application Number:
  US13/626,798
• Publication Number:
  US 20130082650A1
• Time in Patent Office: 1,421 Days
• Field of Search: 320/108
• US Class Current: 1/1
• 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 transmission device, for a wireless charging device, comprising:

a primary coil;

a detection unit configured to generate a sensing signal, upon receiving a feedback remaining amount of a current supplied from the primary coil, wherein the feedback remaining amount of the current supplied from the primary coil corresponds to a difference between an amount of a current to be transmitted from the primary coil and an amount of a current that has been transmitted from the primary coil, and wherein the detection unit comprises an isolation unit configured to prevent interference with main power when the feedback remaining amount of current is fed back from the primary coil; and

a controller configured to;

determine the presence or absence of the reception device, by comparing the sensing signal with a pre-set reference signal generated during an absence or presence of the reception device, and

generate a control signal to control a voltage provided to the primary coil, based on the determination of the presence or absence of the reception device.

2. The wireless transmission device according to claim 1, wherein when the feedback remaining amount of current declines, the detection unit is configured to generate a sensing signal indicating that the reception device is present.

3. The wireless transmission device according to claim 1, wherein when the feedback remaining amount of current increases, the detection unit is configured to generate a sensing signal indicating that the reception device is not present.

4. A wireless transmission device, for a wireless charging device, comprising:

a power source unit configured to generate charging power, by using an external power source, and configured to transmit power via the primary coil;

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

a detection unit, electrically connected with a primary coil, and configured to generate a sensing signal, upon receiving a feedback remaining amount of a current, wherein the feedback remaining amount of the current corresponds to a difference between an amount of a current to be transmitted from the primary coil and an amount of a current that has been transmitted from the primary coil, and wherein the detection unit comprises an isolation unit configured to prevent interference with main power when the feedback remaining amount of current is fed back from the primary coil; and

a controller configured to;

determine the presence or absence of the reception device, by comparing the sensing signal with a pre-set reference signal generated during an absence or presence of the reception device, and

generate a control signal to drive the PA driving unit, based on the determination of the presence or absence of the reception device.

5. The wireless transmission device according to claim 4, wherein the detection unit further includes:

a sensing unit connected to the isolation unit, configured to sense the feedback remaining amount of current supplied from the primary coil via the isolation unit, and configured to generate a measurement signal;

a comparison unit configured to compare a signal provided from the isolation unit, with the measurement signal provided from the sensing unit, to generate a comparison signal; and

a calculation unit configured to digitalize the comparison signal output from the comparison unit, and configured to generate the sensing signal.

6. The wireless transmission device according to claim 5, wherein the isolation unit includes a transformer.

7. The wireless transmission device according to claim 5, wherein the sensing unit is configured to include a resistor, wherein 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.

8. The wireless transmission device according to claim 5, wherein when the feedback remaining amount of current declines, the detection unit is configured to generate a sensing signal indicating that the reception device is present.

9. The wireless transmission device according to claim 5, wherein when the feedback remaining amount of current increases, the detection unit is configured to generate a sensing signal indicating that the reception device is not present.

10. The wireless transmission device according to claim 4, wherein when the sensing signal is smaller than the pre-set reference signal, the controller is configured to recognize that the reception device is present, and is configured to generate a control signal to activate the PA driving unit.

11. The wireless transmission device according to claim 4, wherein when the sensing signal is greater than the pre-set reference signal, the controller is configured to recognize that the reception device is not present, and is configured to generate a control signal to deactivate the PA driving unit.

12. A wireless transmission method, of a wireless charging device, comprising:

detecting a feedback remaining amount of a current supplied from a primary coil, wherein the feedback remaining amount of the current corresponds to a difference between an amount of a current to be transmitted from the primary coil and an amount of a current that has been transmitted from the primary coil;

generating a sensing signal based on the feedback remaining amount;

determining the presence or absence of the reception device, by comparing the sensing signal with a pre-set reference signal generated during an absence or presence of the reception device;

controlling, based on the determination, a voltage input to the primary coil; and

preventing interference with main power when the feedback remaining amount of current is fed back from the primary coil.

13. The wireless transmission method according to claim 12, wherein when the feedback remaining amount of current declines, a sensing signal indicating that the reception device is present is generated.

14. The wireless transmission method according to claim 12, wherein when the feedback remaining amount of current increases, a sensing signal indicating that the reception device is not present is generated.

15. The wireless transmission method according to claim 12, wherein when the sensing signal is compared to the pre-set reference signal, and found to be smaller than the pre-set reference signal, the presence of the reception device is recognized, and a control signal to activate the PA driving unit is generated.

16. The wireless transmission method according to claim 12, wherein when the sensing signal is compared to the pre-set reference signal, and found to be greater than the pre-set reference signal, the absence of the reception device is recognized, and the control signal to deactivate a PA driving unit is generated.