Wireless power bridge

• US 8,729,734 B2
• Filed: 02/29/2008
• Issued: 05/20/2014
• 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): Barnie, Rexford
• Assistant Examiner(s): INGE, JOSEPH N
• Application Number:
  US12/040,783
• Publication Number:
  US 20090127937A1
• Time in Patent Office: 2,272 Days
• Field of Search: 307/104, 320/108
• 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: 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. A method of directing power wirelessly through a solid object, comprising:

generating, by a transmitting antenna, a magnetic field, the transmitting antenna located on one side of a solid object, the solid object comprising a wall or window;

coupling a receiving antenna to the magnetic field, the receiving antenna located on another side of the solid object;

producing, by the receiving antenna, an output that includes power transferred from said magnetic field; and

adjusting a resonant frequency of the transmitting antenna, said adjusting causes an increase in power transfer efficiency between the transmitting antenna and the receiving antenna, said adjusting of the resonant frequency based on a current measurement taken by a sensor.

2. A method as in claim 1, wherein the transmitting antenna and the receiving antenna are each resonant antennas which are tuned at a substantially resonant frequency of the receiving antenna.

3. A method as in claim 1, wherein said solid object cannot be seen through, and further comprising indicating an alignment of said transmitting antenna and said receiving antenna.

4. A method as in claim 1, further comprising:

receiving, at a transmitting circuit, AC power from an AC power source; and

converting the power into a form which can be transmitted by said transmitting antenna as a magnetic field.

5. A method as in claim 4, further comprising:

receiving, at a receiving circuit, power that has been induced into said receiving antenna;

converting said power into electrical power; and

coupling said electrical power to a power output jack.

6. A method as in claim 5, wherein said power output jack provides AC power.

7. A method as in claim 4, wherein said power converter in said transmitting circuit operates without transformers.

8. A method as in claim 4, wherein said transmitting circuit includes a control system that senses at least one parameter indicative of power transmission, and produces at least one control signal that can change based on said sensed parameter.

9. A method as in claim 8, wherein said control signal controls operation of at least one element of said transmitting circuit.

10. A method as in claim 8, wherein said transmitting circuit includes at least one power converting element that is driven by at least one frequency from a frequency generation and control unit.

11. A method as in claim 1, further comprising controlling power and increasing transfer efficiency, without an additional communication between the receiving antenna and the transmitting antenna, by stimulating and sensing the characteristics of the receiving antenna and its behavioral pattern.

17. A method as in claim 8, wherein said transmitting circuit includes at least one tuning network, and wherein said tuning network is driven by at least one control signal from a frequency generation and control unit.

12. A system for directing power wirelessly through a solid object, comprising:

a transmitting antenna configured to generate an AC magnetic field;

a transmitting circuit, coupled to said transmitting antenna, and operative to receive power from an AC connection, and to produce an output power which is coupled to said transmitting antenna and which drives said transmitting antenna in a substantially resonant state;

a receiving antenna configured to receive power from said AC magnetic field and transmitted by said transmitting antenna across a substantially solid object which is one of a solid wall or window;

a receiving circuit, coupled to receive power transferred at substantial resonance that has been received by said receiving antenna, and to produce an output power based on said receiving of the power by said receiving antenna; and

at least one sensor coupled to the transmitting antenna, the sensor configured to produce an output based on a measured current of the transmitting antenna, the output used as a basis for modifying a resonant frequency of the transmitting antenna so as to increase power transfer efficiency between the transmitting antenna and the receiving antenna.

13. A system as in claim 12, wherein at least one of said receiving antenna or said transmitting antenna includes a detection part that detects information indicative of an alignment between said transmitting and receiving antennas.

14. A system as in claim 12, wherein each of said transmitting and receiving antennas has a Q value greater than 200.

15. A system as in claim 12, wherein each of said transmit and receive antennas has wire with an insulation capable of withstanding at least 1000 V.

16. A system as in claim 12, wherein said transmitting circuit further comprises:

an inverter that creates a waveform with a frequency value, said waveform coupled to said transmitting antenna, and a tuning circuit that changes the resonance frequency of said transmitting antenna.

18. A system as in claim 12, wherein said receiving circuit comprises a synchronous rectifier to reduce power conversion losses.

19. A wireless power bridge, comprising:

a transmitting unit configured to receive AC power, and to carry out an AC to AC power conversion, the transmitting unit including a transmitting antenna and at least one sensor configured to produce an output based on a measured current of the transmitting antenna;

a resonant transmitting antenna unit, separate from the transmitting unit and coupled to the transmitting unit, said resonant transmitting antenna unit composed of at least one wire loop and a principle capacitor, said resonant transmitting antenna unit including an antenna tuning circuit to tune a resonant frequency of the transmitting antenna based on the output produced by the sensor;

a resonant receiving antenna unit configured to receive power transferred at a substantially resonant frequency of the resonant receiving antenna unit, the resonant receiving antenna unit comprising at least one wire loop and another principle capacitor to achieve the substantially resonant frequency; and

a receiving unit, separate from said resonant receiving antenna unit, and configured to accommodate a received power conversion, the receiving unit comprising an antenna tuning and matching circuit configured to tune a resonance frequency of the resonant receiving antenna unit and to match said received power conversion to a source impedance of said resonant receiving antenna unit.

20. A wireless power bridge as in claim 19, wherein said transmitting unit is configured to control power and increase transfer efficiency without an additional communication between the receiving unit and the transmitting unit, by stimulating and sensing the characteristics of the receiver and its behavioral pattern.

21. A wireless power bridge as in claim 19, wherein said receiving unit is configured to control power and increase transfer efficiency independently of the transmitting unit without additional communication between transmitting unit and receiving unit.

22. A wireless power bridge as in claim 19, wherein said receiving unit includes a synchronous rectifier to reduce power conversion losses.

23. A wireless power bridge as in claim 19, wherein said transmitting unit automatically enters into a stand-by mode when no receiver can be detected, or when coupling to the receiver is below a specified level, wherein while in said stand-by mode, said transmitting unit operates at a reduced power level which is sufficient to detect a presence of a receiver.

24. A wireless power bridge as in claim 19, wherein said transmitting unit detects a presence of a receiver through stimulating and sensing the characteristics of a receiver and its behavioral pattern.

25. A wireless power bridge as in claim 19, wherein said transmitting unit uses a fixed frequency for wireless power transfer derived from a crystal stabilized oscillator.

26. A wireless power bridge as in claim 19, wherein said antennas are coupled via a double wire power cord.

27. A method of directing power wirelessly through a solid object, comprising:

applying power from an AC outlet to a power transmitting device on a first side of a solid object, where the solid object is an object from the group comprising of a solid wall or a solid window;

wirelessly transmitting a magnetic signal from said power transmitting device;

receiving said magnetic signal on a second side of the solid object;

creating power output on the second side of the solid object, in a power receiving device, based on the wirelessly transmitted power transferred at substantial resonance; and

adjusting a resonant frequency of the first power transmitting device, said adjusting causes an increase in power transfer efficiency between the power transmitting device and the power receiving device, said adjusting of the resonant frequency based on a current measurement taken by a sensor.

28. A method as in claim 27, further comprising a first part in said power transmitting device, and a second part in second power receiving device, wherein an efficiency of power transmission depends on alignment between said first and second parts.

29. A method as in claim 28, wherein said solid object cannot be seen through, the method further comprising indicating an alignment of said first part and said second part.

30. A method of directing power wirelessly through a solid object, comprising:

generating, by a transmitting antenna, a magnetic field, the transmitting antenna located on one side of a solid object;

coupling, by a receiving antenna, to the magnetic field, the receiving antenna located on another side of the solid object;

producing, by the receiving antenna, an output that includes power transferred from said magnetic field; and

adjusting a resonant frequency of the transmitting antenna, said adjusting causes an increase in power transfer efficiency between the transmitting antenna and the receiving antenna, said adjusting of the resonant frequency based on a current measurement taken by a sensor.

31. A method as in claim 30, wherein the transmitting antenna and the receiving antenna are each resonant antennas which are tuned at a substantially resonant frequency of the receiving antenna.

32. A method as in claim 30, wherein said solid object cannot be seen through, and further comprising indicating an alignment of said transmitting antenna and said receiving antenna.

33. A method as in claim 30, further comprising:

receiving, at a transmitting circuit, AC power from an AC power source; and

converting the received AC power into a form which can be transmitted by said transmitting antenna as a magnetic field.

34. A method as in claim 33, further comprising:

receiving, at a receiving circuit, power that has been induced into said receiving antenna;

converting said power into electrical power; and

coupling said electrical power to a power output jack.

35. A method as in claim 34, wherein said power output jack provides AC power.

36. A method as in claim 35, wherein said power converter in said transmitting circuit operates without transformers.

37. A method as in claim 33, wherein said transmitting circuit includes a control system that senses at least one parameter indicative of power transmission, and produces at least one control signal that can change based on said sensed parameter.

38. A method as in claim 37, wherein said control signal controls operation of at least one element of said transmitting circuit.

39. A method as in claim 37, wherein said transmitting circuit includes at least one power converting element that is driven by at least one frequency from said frequency generation and control unit.

40. A method of directing power wirelessly through a solid object, comprising:

applying power from an AC outlet to a power transmitting device on a first side of a solid object;

wirelessly transmitting a magnetic signal from said power transmitting device;

receiving said magnetic signal on a second side of the solid object;

creating power output on the second side of the solid object, in a power receiving device, based on the wirelessly transmitted magnetic signal being transferred at substantial resonance; and

adjusting a resonant frequency of the power transmitting device, said adjusting causes an increase in power transfer efficiency between the power transmitting device and the power receiving device, said adjusting of the resonant frequency based on a current measurement taken by a sensor.

41. A method as in claim 40, further comprising a first part in said power transmitting device, and a second part in said power receiving device, wherein an efficiency of power transmission depends on alignment between said first and second parts.

42. A method as in claim 41, wherein said solid object cannot be seen through, and further comprising indicating an alignment of said first part and said second part.

43. A system for directing power wirelessly through a solid object, comprising:

a transmitting antenna configured to generate a magnetic field from an AC connection;

a transmitting circuit, coupled to said transmitting antenna, and operative to receive power from the AC connection, and to produce output power which is coupled to said transmitting antenna and which drives said transmitting antenna to create AC power wirelessly in a receiving antenna configured to receive power from said magnetic field; and

at least one sensor coupled to the transmitting antenna, the at least one sensor configured to produce an output based on a measured current of the transmitting antenna, the output used as a basis for modifying a resonant frequency of the transmitting antenna so as to increase power transfer efficiency between the transmitting antenna and the receiving antenna.

44. A system for directing power wirelessly through a solid object, comprising:

a receiving antenna configured to receive power from magnetic field transmitted by a transmitting antenna that has been created from an AC connection, said receiving antenna adapted for mounting adjacent to a solid object, with said solid object located between said receiving antenna and said transmitting antenna;

a receiving circuit, coupled to receive power transferred at substantial resonance that has been received by said receiving antenna, and to produce output AC power based on said receiving by said receiving antenna; and

at least one sensor coupled to the receiving antenna, the at least one sensor configured to produce an output based on a measured current of the receiving antenna, the output used as a basis for modifying a resonant frequency of the receiving antenna so as to increase power transfer efficiency between the transmitting antenna and the receiving antenna.

45. A method of directing power wirelessly through a solid object, comprising:

generating, by a transmitting antenna, a magnetic field from an AC connection;

receiving, by a transmitting circuit coupled to said transmitting antenna, power from the AC connection;

producing, by the transmitting circuit, output power which is coupled to said transmitting antenna and which drives said transmitting antenna to create AC power wirelessly in a receiving antenna configured to receive power from said magnetic field; and

producing, by at least one sensor coupled to the transmitting antenna, an output based on a measured current of the transmitting antenna, the output used as a basis for modifying a resonant frequency of the transmitting antenna so as to increase power transfer efficiency between the transmitting antenna and the receiving antenna.

46. An apparatus for directing power wirelessly through a solid object, comprising:

means for generating magnetic field from an AC connection;

means for receiving power from the AC connection, the means for receiving comprising means for producing output power which is coupled to said means for generating and which drives said means for generating to create AC power wirelessly in a receiving antenna configured to receive power from said magnetic field; and

means for producing an output based on a measured current of the means for generating, the output used as a basis for modifying a resonant frequency of the means for generating so as to increase power transfer efficiency between the means for generating and the receiving antenna.

47. A method of directing power wirelessly through a solid object, comprising:

receiving, by a receiving antenna, power from a magnetic field transmitted by a transmitting antenna that has been created from an AC connection, said receiving antenna adapted for mounting adjacent to a solid object, said received power transferred at substantial resonance;

receiving, by a receiving circuit, said received power from the receiving antenna;

producing, by the receiving circuit, output AC power based on said received power; and

producing, by at least one sensor coupled to the receiving antenna, an output based on a measured current of the receiving antenna, the output used as a basis for modifying a resonant frequency of the receiving antenna so as to increase power transfer efficiency between the transmitting antenna and the receiving antenna.

48. An apparatus for directing power wirelessly through a solid object, comprising:

first means for receiving power from a magnetic field transmitted by a transmitting antenna that has been created from an AC connection, said first means adapted for mounting adjacent to a solid object, said received power transferred at substantial resonance;

second means for receiving said received power from the first means, said second means comprising means for producing output AC power based on said received power; and

means for producing an output based on a measured current of the first means, the output used as a basis for modifying a resonant frequency of the first means so as to increase power transfer efficiency between the transmitting antenna and the first means.