Wireless power bridge

• US 9,966,188 B2
• Filed: 03/05/2014
• Issued: 05/08/2018
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Cook, Nigel P., Sieber, Lukas, Widmer, Hanspeter
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Inge, Joseph
• Application Number:
  US14/198,322
• Publication Number:
  US 20140183969A1
• Time in Patent Office: 1,525 Days
• Field of Search: 307104
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01F 5/003 Printed circuit coils
• CPC Class Codes: H01F 7/20 without armatures cores H01F3/00; coils H01F5/00 ; shaping metal by applying magnetic forces B21D26/14; electromagnets specially adapted for NMR applications G01R33/381
• CPC Class Codes: H01Q 1/1285 with capacitive feeding through the windscreen
• CPC Class Codes: H01Q 1/248 provided with an AC/DC converting device, e.g. rectennas
• 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 50/90 involving detection or optimisation of position, e.g. alignment

Abstract

A wireless power bridge that allows magnetic transmission of energy across a solid barrier such as a wall. A circuit is described for controlling the operation.

Claims

1. An apparatus for transferring power wirelessly, comprising:

a transmit antenna configured to transmit power wirelessly via a magnetic field; and

a transmitting unit coupled to the transmit antenna, the transmitting unit comprising a control subunit configured to change a duty cycle of a switching waveform that causes the transmitting unit to intermittently transmit power, the transmitting unit configured to cause the transmit antenna to;

transmit power wirelessly, via the magnetic field, at a first power level in a first mode;

intermittently transmit power, via the magnetic field, at a second power level, lower than the first power level, in a second mode, the second power level sufficient to detect a presence of a receiver, and

in the second mode, detect the presence of the receiver by stimulating and sensing the characteristics of the receiver and its behavioral pattern.

2. An apparatus as in claim 1, wherein the transmitting unit is further configured to cause the transmit antenna to transmit power wirelessly via the magnetic field at the first power level when the receiver is detected.

3. An apparatus as in claim 2, further comprising a resonant transmit circuit comprising the transmit antenna, the transmitting unit configured to tune a resonant frequency of the transmit circuit.

4. An apparatus as in claim 1, wherein the transmitting unit is further configured to enter into the second mode in response to detecting no receiver is present or when coupling of power to the receiver is below a specified level.

5. An apparatus as in claim 1, wherein the transmitting unit is configured to operate at a fixed frequency for wireless power transfer.

6. The apparatus of claim 1, wherein the transmitting unit comprises an indicator configured to indicate the presence of the receiver device.

7. A method of transferring power wirelessly, comprising:

transmitting, via a magnetic field, power wirelessly at a first power level in a first mode;

intermittently transmitting power, via the magnetic field, at a second power level, lower than the first power level, during a second mode, the second power level sufficient to detect a receiver device, wherein intermittently transmitting power comprises changing a duty cycle of a switching waveform;

detecting a presence of the receiver device when the receiver device is positioned within the magnetic field at the second power level by stimulating and sensing the characteristics of the receiver device and its behavioral pattern.

8. A method as in claim 7, further comprising transmitting, via the magnetic field, power wirelessly at the first power level when a receiver device is detected.

9. A method as in claim 8, further comprising tuning a resonant frequency of a resonant transmit circuit configured to transmit the power wirelessly via the magnetic field.

10. A method as in claim 7, further comprising entering into the second mode when no receiver device is detected or when coupling of power to the receiver device is below a specified level.

11. A method as in claim 7, further comprising operating the transmitting unit at a fixed frequency for wireless power transfer.

12. The method of claim 7, further comprising indicating the presence of the receiver device.

13. An apparatus for transferring power wirelessly, comprising:

means for transmitting, via a magnetic field, power wirelessly at a first power level in a first mode;

means for intermittently transmitting power, via the magnetic field, at a second power level, lower than the first power level, during a second mode, the second power level sufficient to detect a receiver device, wherein the means for intermittently transmitting power comprises a means for controlling a duty cycle of a switching waveform; and

means for detecting a presence of the receiver device when the receiver device is positioned within the magnetic field and the apparatus is operating at the second power level by stimulating and sensing the characteristics of the receiver device and its behavioral pattern.

14. An apparatus as in claim 13, wherein the transmitting means is configured to transmit, via the magnetic field, power wirelessly the first power level higher than the second power level when the receiver device is detected.

15. An apparatus as in claim 14, wherein the means for transmitting comprises a resonant means, and wherein the apparatus further comprises a means for tuning a resonant frequency of the resonant means for transmitting the power wirelessly via the magnetic field.

16. An apparatus as in claim 13, further comprising means for entering into the second mode when no receiver device is detected or when coupling of power to the receiver device is below a specified level.

17. An apparatus as in claim 13, wherein the transmitting means is further configured to enter into the second mode in response to detecting no receiver device is present or when coupling of power to the receiver device is below a specified level.

18. An apparatus as in claim 13, wherein the transmitting means is configured to operate at a fixed frequency for wireless power transfer.

19. The apparatus of claim 13, further comprising means for indicating the presence of the receiver device.