Electric device, wireless power transmission device, and power transmission method thereof

• US 8,110,949 B2
• Filed: 10/20/2009
• Issued: 02/07/2012
• Est. Priority Date: 05/28/2009
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Kim, Yong Hae, Kang, Seung Youl, Lee, Myung Lae, Zyung, Taehyoung, Lee, Jong-Moo, Cheon, Sang Hoon
• Primary Examiner(s): DeBeradinis, Robert L.
• Application Number:
  US12/581,923
• Publication Number:
  US 20100301678A1
• Time in Patent Office: 840 Days
• Field of Search: 307/104
• US Class Current: 307/104
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• 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 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection

Abstract

Provided is a wireless power transmission device. The wireless power transmission device includes a power coil in which a high frequency current is applied, a transmission coil in which the high frequency current is induced by magnetic induction, the transmission coil configured to generate an non-radiative electromagnetic wave when the transmission coil has the same resonant frequency as an at least one external target device, and a resonant frequency regulator configured to regulate the resonant frequency of the transmission coil. The wireless power transmission device can transmit the power when it has the same resonant frequency as the target device. Therefore, the overheating due to an eddy current may not occur, and the design may be easily varied.

Claims

1. A wireless power transmission device, comprising:

a power coil to which a first high frequency current is applied;

a transmission coil in which a second high frequency current corresponding to the first high frequency current is induced by magnetic induction; and

a resonant frequency regulator configured to adjust a resonant frequency of the transmission coil to equal a resonant frequency of an external target device,

wherein the transmission coil is configured to generate a non-radiative electromagnetic wave to transfer power to the external target device when the resonant frequency of the transmission coil is equal to the resonant frequency of the external target device.

2. The wireless power transmission device of claim 1, wherein the transmission coil includes a plurality of transmitting coils and the resonant frequency regulator adjusts a distance between the transmitting coils to adjust the resonant frequency of the transmission coil.

3. The wireless power transmission device of claim 1, wherein the transmission coil includes a plurality of transmitting coils and the resonant frequency regulator adjusts the resonant frequency of the transmission coil by inserting a dielectric between the transmitting coils.

4. The wireless power transmission device as recited in claim 1, wherein the power coil has a diameter greater than about 3 mm and has only one turn.

5. The wireless power transmission device as recited in claim 1, wherein a diameter of the transmission coil is greater than 3 mm.

6. The wireless power transmission device according to claim 1, wherein the transmission coil transfers power to the external target device only when the transmission coil has the same resonant frequency as the external target device.

7. An electric device for receiving power from a wireless power transmission device, comprising:

a receiving coil inserted into a PC board, the receiving coil being configured to receive the power through a non-radiative electromagnetic wave generated from the wireless power transmission device when the receiving coil has the same resonant frequency as does the wireless power transmission device, the receiving coil having a spiral structure; and

a loading coil configured to receive the power from the receiving coil by magnetic induction to supply the power to a target device.

8. The electric device for receiving power from a wireless power transmission device as recited in claim 7, wherein the receiving coil has a diameter of about 0.05 mm to about 0.20 mm and is ultrasonically bonded to the PC board.

9. The electric device for receiving power from a wireless power transmission device as recited in claim 7, wherein the receiving coil includes copper plating.

10. The electric device for receiving power from a wireless power transmission device as recited in claim 7, wherein the loading coil has a single turn and has a diameter of about 3 mm.

11. The electric device for receiving power from a wireless power transmission device as recited in claim 10, wherein the receiving coil includes a plurality of turns.

12. The electric device for receiving power from a wireless power transmission device as recited in claim 11, further including a DC converter electrically connected to the loading coil.

13. The electric device for receiving power from a wireless power transmission device as recited in claim 7, wherein the receiving coil receives the power from the wireless power transmission device only when the receiving coil has the same resonant frequency as the wireless power transmission device.

14. A wireless power transmission system comprising:

an electric device including

a receiving coil configured to receive power through a non-radiative electromagnetic wave and having a resonant frequency, and

a loading coil configured to receive the power from the receiving coil by magnetic induction to supply the power to a target device; and

a wireless power transmission device including

a power coil to which a first high frequency current is applied,

a transmission coil in which a second high frequency current corresponding to the first high frequency current is induced by magnetic induction, and

a resonant frequency regulator configured to adjust a resonant frequency of the transmission coil to equal the resonant frequency of the receiving coil,

wherein the transmission coil is configured to generate a non-radiative electromagnetic wave to transfer the power to the electric device when the resonant frequency of the transmission coil is equal to the resonant frequency of the receiving coil.

15. The wireless power transmission system of claim 14, wherein the transmission coil includes a plurality of transmitting coils and the resonant frequency regulator adjusts a distance between the transmitting coils to adjust the resonant frequency of the transmission coil.

16. The wireless power transmission device of claim 14, wherein the transmission coil includes a plurality of transmitting coils and the resonant frequency regulator adjusts the resonant frequency of the transmission coil by inserting a dielectric between the transmitting coils.

17. The wireless power transmission system as recited in claim 14, wherein the transmission coil transfers the power to the electric device only when the transmission coil has the same resonant frequency as the receiving coil.

18. A wireless power transmission device, comprising:

a power coil in which a first high frequency current is applied;

a transmission coil having a plurality of coils and in which a second high frequency current is induced by magnetic induction; and

a resonant frequency regulator configured to adjust a resonant frequency of the transmission coil to equal a resonant frequency of an external target device, the resonant frequency regulator adjusting a distance between the plurality of coils of the transmission coil to adjust the resonant frequency of the transmission coil to be equal to the resonant frequency of the external target device,

wherein the transmission coil is configured to generate a non-radiative electromagnetic wave to transfer power to the external target device when the resonant frequency of the transmission coil is equal to the resonant frequency of the external target device.

19. The wireless power transmission device according to claim 18, wherein the resonant frequency regulator further adjusts the resonant frequency of the transmission coil by inserting a dielectric between the plurality of coils of the transmission coil.

20. The wireless power transmission device according to claim 18, wherein the transmission coil transfers power to the at least one external target device only when the transmission coil has the same resonant frequency as the at least one external target device.