System and method for inductive charging of portable devices

• US 8,629,654 B2
• Filed: 04/09/2012
• Issued: 01/14/2014
• Est. Priority Date: 01/31/2006
• Status: Active Grant

• Current Assignee: Mojo Mobility, Inc.
• Original Assignee: Mojo Mobility, Inc.
• Inventors: Partovi, Afshin, Sears, Michael
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US13/442,698
• Publication Number:
  US 20120256585A1
• Time in Patent Office: 645 Days
• Field of Search: 320/107, 320/108, 320/112, 320/114, 320/115, 320/150, 320/180
• US Class Current: 320/108
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/361 made of combinations of electrically conductive material and ferromagnetic material
• CPC Class Codes: H01F 27/363 made of electrically conductive material
• CPC Class Codes: H01F 27/366 made of ferromagnetic material
• 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: H02J 2310/22 The load being a portable electronic device
• 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 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• 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 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication

Abstract

A system and method for variable power transfer in an inductive charging or power system. In accordance with an embodiment the system comprises a pad or similar base unit that contains a primary, which creates an alternating magnetic field. A receiver comprises a means for receiving energy from the alternating magnetic field and transferring it to a mobile device, battery, or other device. In accordance with various embodiments, additional features can be incorporated to provide greater power transfer efficiency, and to allow the system to be easily modified for applications that have different power requirements; such as variations in the material used to manufacture the primary and/or the receiver coils; modified circuit designs to be used on the primary and/or receiver side; and additional circuits and components that perform specialized tasks, such as mobile device or battery identification, and automatic voltage or power-setting for different devices or batteries.

Claims

1. A system for inductive powering and charging of portable devices or batteries, comprising:

a base unit, including one or more primary coils which are capable of generating an inductive field for use in powering or charging one or multiple portable devices or batteries simultaneously, wherein each primary coil is positioned within the base unit so that an electrical current can be passed through the primary coil to generate an inductive field;

a receiver unit, including a receiver coil which is coupled to or incorporated into a portable device or battery, or a skin, case, or battery door associated therewith, wherein the receiver coil receives energy inductively from the one or more primary coils and uses it to charge or power the portable device or battery; and

components within the base unit for allowing a degree of position independence of the portable device, battery, skin, case, or battery door with respect to the base unit, including selectively activating an appropriate number of the one or more primary coils, including

verifying a presence of the receiver unit placed close to the base unit,

activating the appropriate number of primary coils to be used with the receiver unit and its portable device, battery, skin, case, or battery door, and

communicating information for use in managing power transfer to the portable device or battery.

2. The system of claim 1, wherein the base unit includes a plurality of primary coils, and wherein activating the appropriate number of the plurality of primary coils includes controlling the on/off operation of the primary coils in the vicinity of the receiver unit and its portable device, battery, skin, case, or battery door.

3. The system of claim 1, wherein the base unit and/or the receiver unit both include microcontrollers, wherein the microcontroller in the base unit and/or the receiver unit provides communication between the base unit and the receiver unit for use in controlling charging.

4. The system of claim 1, wherein the base unit performs an additional verification step prior to activating charging, to verify the identity or permissions of the receiver unit or the portable device, battery, skin, case, or battery door.

5. The system of claim 1, wherein, within the base unit, a plurality of primary coils are integrated into a pad-like charger or power supply and wherein the coils are used to form a coil mosaic and an effective area of charging or power.

6. The system of claim 1, wherein the base unit includes a plurality of primary coils, and wherein each one or a group of the plurality of coils are driven by an individual drive circuit to provide power to each coil and to selectively activate one or more coils.

7. The system of claim 1, wherein each of the one or more primary coils or a group of them includes a switch component, and wherein the base unit includes a microcontroller that periodically switches alternating voltage to one or more primary coils, monitors the current therein, and uses the current to sense the proximity of a receiver unit to a particular coil or a region thereof, and activate charging in that particular coil, or a selection of coils in that region.

8. The system of claim 1, wherein a plurality of layers of primary coils are layered upon one another to create an effective area of charging or power, and so that powering any one or a selection of the primary coils allows a receiver unit within the effective area to be charged.

9. A mobile device capable of being inductively powered or charged comprising:

a battery; and

a receiver unit, for one of inductively powering the mobile device or charging the battery in the mobile device,

wherein the receiver unit is one of attached to or incorporated into the battery or the mobile device or a skin, case, or battery door associated therewith, and includes a receiver coil which receives energy inductively from one or more primary coils in a base unit and uses it to charge or power the mobile device or battery, and

wherein the base unit allows a degree of position independence of the mobile device, battery, skin, case, or battery door with respect to the base unit, including selectively activating an appropriate number of its one or more primary coils, including verifying a presence of the receiver unit placed close to the base unit, activating the appropriate number of primary coils to be used with the receiver unit and its mobile device, battery, skin, case, or battery door; and

wherein the receiver unit communicates with the base unit to communicate information for use in managing power transfer to the mobile device or battery.

10. The mobile device of claim 9, wherein the information communicated between the receiver unit with the base unit includes information about the presence of the mobile device adjacent to the base unit and/or wherein the base unit stores charging or power requirements for mobile devices which can be charged or powered by the base unit.

11. A system for use with a mobile device or battery for charging or powering the mobile device or battery inductively, comprising:

a base unit, including one or more primary coils which are capable of generating an inductive field for use in powering or charging one or multiple mobile devices or batteries simultaneously, wherein each primary coil is positioned within the base unit so that an electrical current can be passed through the primary coil to generate an inductive field;

components within the base unit for allowing a degree of position independence of a mobile device or battery, or skin, case, or battery door associated therewith, with respect to the base unit, including selectively activating an appropriate number of the one or more primary coils, including

verifying a presence of a receiver unit placed close to the base unit,

activating the appropriate number of primary coils to be used with the receiver unit and its mobile device, battery, skin, case, or battery door, and

communicating information for use in managing power transfer to the mobile device or battery; and

wherein the inductive field is used to generate a current in receiver unit, to charge or power the mobile device or battery.

12. The system of claim 11, wherein one or more of the primary coils are manufactured on printed circuit boards and are manufactured to have a low resistance.

13. The system of claim 11, further comprising a battery coupled to and powering the base unit, and wherein the battery can be occasionally charged by an external power supply to maintain a charge sufficient to power the base unit for a period of time.

14. The system of claim 11, further comprising one or more of

a solar cell coupled to a battery in the base unit, for charging the battery in the base unit;

a data storage component for storage of data, for subsequent transmission of data to or from the mobile device; and

/or

a cover surface of the base unit that includes a decorative or non-slip surface.

15. The system of claim 11, wherein the base unit includes a plurality of modular chargers or power supplies that can be interconnected to form the base unit.

16. The system of claim 11, wherein the mobile device to be charged or powered includes

a charging circuit having a Zener diode and/or voltage regulator, wherein the Zener diode limits the voltage to the mobile device or battery to a predetermined maximum voltage, and

a switch that includes a MOSFET and a capacitor, and wherein alternating switching in each of the one or more primary coils is automatically started by the MOSFET when the base unit detects a mobile device or battery placed close to or aligned with that primary coil.

17. The system of claim 11, further comprising a switch within the base unit for adjusting and/or controlling the power into the one or more primary coils under different load conditions, to maintain high efficiency during different load conditions or charging stages.

18. The system of claim 17, wherein the switch includes a zero voltage switching or zero current switching switch geometry, and wherein the controlling of output power is achieved by changing the frequency of the switching operation.

19. The system of claim 11, wherein the base unit includes a microcontroller for controlling one or more of the verifying a presence of a receiver unit placed close to the base unit, activating the appropriate number of primary coils to be used with the receiver unit and its mobile device, battery, skin, case, or battery door, and/or communicating information for use in managing power transfer to the mobile device or battery.

20. The system of claim 19, wherein the microcontroller includes a firmware which is used to configure the microcontroller.

21. The system of claim 19, wherein the microcontroller monitors current flow, and communicates information about current flow between the base unit and the receiver unit for use in controlling charging.

22. The system of claim 11, wherein the base unit includes one or more magnets that exert an attractive force to cause the primary coil in the base unit to become more aligned with the receiver unit.

23. The system of claim 22, wherein the one or more magnets are in the form a flat disk, a ring or arc magnet, and optionally include one or more cuts or breaks, and are placed at a center or at an outer edge of the primary coil.

24. The system of claim 11, wherein additional layers are included proximate to the primary coil, to provide one or more of electromagnetic shielding and/or heat dissipation.

25. The system of claim 11, wherein the base unit is powered by another electronic device, such as through a USB connector in the base unit.

26. The system of claim 11, wherein one or more of the primary coils are movable within the base unit, and wherein when a device having a receiver unit is placed on the base unit, the base unit senses the position of the receiver coil and moves the coil to the correct position to optimize power transfer.

27. The system of claim 11, wherein the base unit is incorporated into a compartment in a vehicle.

28. The system of claim 11, wherein the base unit is incorporated into a compartment in one of a briefcase, handbag, backpack, carrier, or clothing.

29. The system of claim 11, wherein the receiver unit is incorporated into one of a holster, case, pouch, bag, wallet, or an equivalent holding, carrying, or storage for the mobile device, which is then used with the base unit.

30. The system of claim 11, wherein upon the base unit being used to charge or power the mobile device or battery, the system further communicates data between the base unit and the mobile device or performs other functions.

31. The system of claim 11, further comprising a thin layer of a copper, aluminum, other metallic or other conductive material, or an organic, nanotech, or other material, deposited upon or covering all or part of the base unit and/or the primary coils, or its other components, to provide selective frequency attenuation and/or reduced undesirable electromagnetic emission during operation of the base unit.

32. The system of claim 31, wherein the thin layer of material is formed by one or more of sputtering, evaporation, electroplating, coating through dipping, Langmuir Blodgett, painting, Ecoplating, or other deposition method used to deposit or coat the appropriate material onto some or all or part of the base unit components, its interior and/or exterior or a combination thereof.

33. The system of claim 31, wherein the thin layer of material is adapted to allow desired low frequency components to pass with little or no attenuation, while greatly reducing undesired higher frequency electromagnetic emissions.