WIRELESS POWER RECEIVER AND WIRELESS POWER TRANSMISSION SYSTEM

• US 20120248882A1
• Filed: 03/28/2011
• Published: 10/04/2012
• Est. Priority Date: 03/28/2011
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: URANO, Takashi
• Granted Patent: US 8,970,069 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• 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 50/12 of the resonant type

Abstract

Power is fed from a feeding coil to a receiving coil L3 by magnetic resonance. The receiving coil L3 and a capacitor C3 are connected in series to constitute a receiving coil circuit. A loading coil L4 electromagnetically coupled to the receiving coil L3 is connected to a load through a rectification circuit 142 to constitute a loading circuit. Placing the rectification circuit 142 on a first flat plate electrode 132 of the capacitor C3 allows heat generated from the rectification circuit 142 to escape to the first flat plate electrode 132.

Claims

1. A wireless power receiver that receives, at a receiving coil, AC power fed from a feeding coil by wireless using a magnetic field resonance phenomenon between the feeding coil and receiving coil, said receiver comprising:

a receiving coil circuit that includes a capacitor constituted by flat plate electrodes facing each other and the receiving coil; and

a loading circuit that includes a loading coil that is magnetically coupled to the receiving coil to receive the AC power from the receiving coil and a load to which the AC power is supplied from the loading coil,

a heating element included in the loading circuit being placed on the electrode.

2. The wireless power receiver according to claim 1, wherein

the loading circuit further comprises a rectification circuit that rectifies the AC power received by the loading coil and supplies the resultant power to the load, and

the rectification circuit is placed on the electrode as the heating element.

3. The wireless power receiver according to claim 1, wherein

a first electrode on which the heating element is placed has a plurality of protrusions.

4. The wireless power receiver according to claim 3, wherein

a second electrode opposite to the first electrode has a plurality of protrusions, and

the protrusions of the first electrode and those of the second electrode face each other alternately.

5. The wireless power receiver according to claim 1, wherein

the receiving coil is wound outside the capacitor.

6. The wireless power receiver according to claim 5, wherein

the loading coil is wound outside the receiving coil.

7. The wireless power receiver according to claim 5, wherein

both or one of the receiving coil and loading coil have a rectangular shape in coil cross-section.

8. The wireless power receiver according to claim 1, wherein

the receiving coil circuit resonates at a resonance frequency of the feeding coil.

9. A wireless power transmission system comprising

the wireless power receiver as claimed in claim 1;

the feeding coil; and

a power supply circuit that supplies the AC power to the feeding coil.

10. The wireless power transmission system according to claim 9, wherein

the power supply circuit supplies the AC power from the feeding coil that does not substantially resonate with power feeding side circuit elements to the receiving coil.

11. The wireless power transmission system according to claim 9, wherein

the feeding coil does not constitute a resonance circuit that resonates with power feeding side circuit elements at a resonance point corresponding to the resonance frequency of the receiving coil.

12. The wireless power transmission system according to claim 9, wherein

no capacitor is inserted in series or in parallel to the feeding coil.

13. The wireless power transmission system according to claim 9, wherein

the feeding coil is connected to the capacitor to constitute a circuit that resonates at the resonance frequency of the receiving coil.