System and method for inductive charging of portable devices

• US 8,169,185 B2
• Filed: 05/07/2008
• Issued: 05/01/2012
• Est. Priority Date: 01/31/2006
• Status: Active Grant

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 the energy from the alternating magnetic field from the pad and transferring it to a mobile device, battery, or other device. In accordance with various embodiments, additional features can be incorporated into the system to provide greater power transfer efficiency, and to allow the system to be easily modified for applications that have different power requirements. These include 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/or charging of portable devices or batteries, comprising:

a base unit such as a charger or power supply, which includes one or more primary coils generally having a plane or curved surface, wherein each of the primary coils can be activated to generate an inductive field in a direction substantially perpendicular to the plane or curved surface of the coil, for use in powering or charging one or more portable devices or batteries,

wherein the base unit can provide power to one or more receiver units associated with one or more portable devices or batteries to be powered or charged, each of which receiver units includes a receiver coil, wherein the receiver unit is coupled to or incorporated into a portable device or battery, or case, skin, or other accessory for use therewith, and wherein the receiver unit receives energy inductively via its receiver coil from the primary coil and uses the energy to power or charge the portable device or battery; and

one or more features within the base unit for allowing that assist in providing position independence of the portable devices or batteries on the base unit, including detecting the presence of one or more portable devices or batteries, and then selectively activating appropriate one or more primary coils so that the base unit can charge or power the one or more portable devices or batteries so detected.

2. The system of claim 1, wherein the base unit includes a plurality of primary coils, and wherein the one or more features within the base unit that assist in providing position independence of the portable devices or batteries on the base unit is used to control the powering on and off or activation of operations of the primary coils in the vicinity of the portable devices or batteries so detected.

3. The system of claim 1, wherein one or both of the base unit and the receiver unit for the portable device or battery include a microcontroller unit which monitors current flow and/or voltage and/or 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 prior to activating the one or more primary coils for powering or charging, to verify the identity or permissions of a portable device or battery being powered or charged.

5. The system of claim 2, wherein the plurality of primary coils are integrated into the base unit such as a charger or power supply, and wherein the plurality of primary coils are used to form a coil mosaic and an effective area of charging or power supply that does not cover more than approximately 95% of the charger or power supply surface.

6. The system of claim 1, wherein each or a selection of the one or more primary coils are driven by one or more drive circuits to selectively power on and off that primary coil or a selection of coils when appropriate, and provide power to a receiver unit nearby.

7. The system of claim 3, wherein a group of one or more primary coils includes a switching component, and wherein the microcontroller unit periodically

starts switching on primary coils in that group in a sequence or individually

monitors the current flow through the primary coil being switched, and

uses the current flow to sense the proximity of a receiver and device or battery to that primary coil, and thereafter activate powering or charging of the portable device or battery via that primary coil, or a selection of primary 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, and so that powering or charging via any one or a selection of the primary coils allows a receiver unit whose receiver coil center is within the effective area to be charged.

14. The system of claim 1 further comprising one or more of

a solar cell, fuel cell, wind power component, crank or other mechanical method or a combination thereof or other renewable or non-renewable power source or other inductive charger or power supply coupled to a battery in the base unit, for charging the battery in the base unit;

and/or

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

/or

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

15. The system of claim 1, wherein

a portion or majority of the charger or power supply is mechanically flexible, and/or

a plurality of modular chargers or power supplies can be interconnected to form a single unit, or folded to save space, and/or

modular units can be added to the base unit to provide added functionality such as a battery, solar cell, fuel cell or crank or other mechanical method or other renewable or non-renewable power source to power the unit, a communication unit for communication of data with a device to be charged, or a storage device to store the communicated data,

or a combination of the above.

16. The system of claim 1, wherein the portable device or battery to be charged or powered includes

a receiver circuit having a regulator and/or shunt regulator such as a Zener diode, wherein the regulator or shunt regulator clamps or regulates the voltage to the portable device or battery or the regulator to a predetermined voltage, and/or

wherein the receiver circuit includes a capacitor for smoothing the output voltage from the receiver coil.

17. The system of claim 1, further comprising means within the base unit for providing control regulation, and/or verification of the power charging and/or powering, including a switch means for adjusting and/or controlling the power into the 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 means is a zero voltage switching or zero current switching geometry, and wherein the adjusting and/or controlling of output power or voltage is achieved by changing the input voltage to the switching circuit in the base unit, or the frequency or duty cycle, or a combination thereof.

19. The system of claim 1, wherein the base unit and the receiver unit communicate wirelessly with one another to perform control and switching functions, and/or to communicate a range of one of either a predefined value of voltage or current, or an appropriate power parameter of the portable device and/or battery.

20. The system of claim 19, wherein the base unit and the receiver unit communicate wirelessly through the same or another set of base unit and receiver coils or antennas by one or more analog or digital wireless links selected from the group comprising Bluetooth, WiFi, NFC, Felica, RFID, Wireless USB, WiMax, or other technologies including custom technologies.

21. The system of claim 1, wherein the system is configured to regulate output power through a wide range, including

while the one or more portable devices or batteries are being charged or the load condition changes to require low output power, using a voltage regulator to switch the input voltage of the base unit between two or more values,

wherein when the output requires low power the voltage regulator is switched on and the output power is maintained by shifting to the appropriate frequency, duty cycle and/or input voltage of the base unit to provide the required output power.

22. The system of claim 1, wherein the base unit includes a plurality of primary coils arranged as a mosaic that provides an effective area of charging, and wherein each or a selection of the primary coils are driven by an individual or multiplicity of drive circuits to provide power to that primary coil or selection of coils, and wherein the base unit can selectively activate one or a selection of the primary coils to alter the location and size of the effective area of charging.

23. The system of claim 1, wherein the base unit includes one or more aligning magnets at or near the one or more primary coils, wherein the aligning magnets encourage the general alignment of a primary coil with a receiver coil using corresponding magnets or magnetic materials at the receiver coil, or at the portable devices or batteries or case, skin, or other accessory for use therewith.

24. The system of claim 23, wherein the aligning magnets in the base unit are oriented so that their magnetic fields are perpendicular to the surface of the base unit.

25. The system of claim 1, wherein one or more primary coils are free to move within a sector or whole of the base unit, and wherein upon placing a portable device or battery or case, skin, or the primary coil moves within its sector or whole of the base unit so that the primary coil and receiver coil are better aligned.

26. The system of claim 25, wherein the one or more primary coils that are free to move within a sector or whole of the base unit are initially disposed within the sector or whole of the base unit and are connected by wires and/or springs carrying power to the primary coil while allowing a degree of movement.

27. The system of claim 25 wherein the base unit includes one or more aligning magnets at or near the primary coil, wherein the aligning magnets encourage the general alignment of the primary coil with a receiver coil using corresponding magnets or magnetic material at the receiver coil, or at the portable devices or batteries or case, skin, or other accessory for use therewith.

28. The system of claim 23, wherein at least some of the magnets or magnetic material are manufactured of non-electrically conductive material and/or are divided or layered into two or more sections, such as semi-circles, including a gap or non-conductive material between the two or more sections, to reduce current circulation within the magnet or magnetic material.

29. The system of claim 23, wherein at least some of the magnets or magnetic materials are placed such that each magnet or magnetic materials do not cover an area extending beyond the center of the coil.

30. The system of claim 1, wherein the base unit is built-in to a portable device such as a mobile phone, laptop, tablet, netbook, camera, MP3 player, GPS, or battery holder, such as a mobile phone holder, belt holder, or case, for receiving and holding the one or more portable devices or batteries during powering or charging.

31. The system of claim 30 wherein the base unit is powered by a battery, solar cell, fuel cell, wind power component, crank or other mechanical method or other renewable or rechargeable or non-renewable power source coupled to the base unit and/or may be itself charged or powered by an inductive charger or power supply.

32. The system of claim 1, wherein at least some of the primary coils or receiver coils are coupled to a magnetic shield and/or heat conductivity layer or component which is positioned, structured and/or patterned to provide removal of heat from the coil.

33. The system of claim 1, wherein the base unit detects the presence of one or more portable devices or batteries using an optical sensor.

34. The system of claim 1, wherein the base unit detects the presence of one or more portable devices or batteries using a magnetic or capacitive sensor.

35. The system of claim 1, wherein the base unit detects the presence of one or more portable devices or batteries using a radiofrequency sensor including RFID, NFC, Felica, Bluetooth, WiFi, Wireless USB or a combination thereof or other technology.

36. The system of claim 1, wherein the base unit detects the presence of one or more portable devices or batteries by periodically switching on primary coils, monitoring the current flow through the primary coil being switched, and using the current flow to determine the presence of the portable devices or batteries.

37. The system of claim 1, wherein the system includes the one or more receiver units.

38. The system of claim 1, wherein the portable device is, or includes a case, skin or other accessory.

9. A portable device capable of being inductively powered and/or charged comprising:

a receiver unit, which includes a receiver coil generally having a planar or curved surface, wherein the receiver unit is coupled to or incorporated into a portable device or battery, or case, skin, or other accessory for use therewith, and wherein the receiver unit is capable of receiving energy from a base unit such as a charger or power supply via an inductive field in a direction substantially perpendicular to the plane or curved surface of its receiver coil, and using the energy to power or charge the portable device or battery; and

a regulator circuit coupled to the receiver unit, that regulates current drawn from the receiver coil and/or output voltage or output current from the receiver unit to be within the range of one of either a predefined value of voltage or current, or an appropriate power parameter of the portable device and/or battery.

10. The portable device or battery of claim 9, wherein the receiver coil receives the inductive field from a primary coil in the base unit, and wherein the primary and/or receiver coils are formed within one or more printed circuit board (PCB) layers and/or using wire coil layers or a combination thereof.

11. The portable device or battery of claim 9, wherein the base unit such as a charger or the power supply, and the portable device, battery, or receiver unit coupled thereto or incorporated therein, communicate with each other to transfer data.

12. The portable device or battery of claim 11, wherein the data transferred includes information about the presence of the portable device or battery adjacent to the charger or power supply and/or wherein the charger or power supply stores charging or power requirements for portable devices or batteries which can be charged or powered by the charger or power supply.

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

a base unit such as a charger or power supply, which includes one or more primary coils generally having a plane or curved surface, wherein each of the primary coils can be activated to generate an inductive field in a direction substantially perpendicular to the plane or curved surface of the coil, for use in powering or charging one or more portable devices or batteries simultaneously;

a battery or fuel cell or renewable or non-renewable power source within or coupled to the base unit; and

wherein the battery or fuel cell or renewable or non-renewable power source can have a charge or power sufficient to power the base unit while disconnected from the external power source, for a period of time.

39. A system for inductive powering and/or charging of portable devices or batteries that includes electromagnetic shielding, comprising:

a base unit such as a charger or power supply, which includes one or more primary coils generally having a plane or curved surface, wherein each of the primary coils can be activated to generate an inductive field in a direction substantially perpendicular to the plane or curved surface of the coil, for use in powering or charging one or more portable devices or batteries simultaneously;

an electromagnetic shielding material or layer or layers in front of the charger or power supply coil(s) that suppresses undesirable electromagnetic radiation during powering or charging of the one or more portable devices or batteries.

40. The system of claim 39 whereby the shielding material or layers contain metal.

41. The system of claim 39 whereby the shielding materials or layers are several micrometers thick.

42. A wearable clothing item which enables inductive powering and/or charging of portable devices or batteries, comprising:

a base unit, within the clothing item, which includes one or more primary coils generally having a plane or curved surface, wherein each of the primary coils can be activated to generate an inductive field in a direction substantially perpendicular to the plane or curved surface of the coil, for use in powering or charging one or more portable devices or batteries simultaneously;

one or more features within the base unit that assist in providing some degree of position independence of the portable devices or batteries with respect to the base unit, including detecting the presence of one or more portable devices or batteries within or on or attached to the clothing item, and then selectively activating appropriate one or more primary coils so that the base unit can charge or power the one or more portable devices or batteries so detected.

43. The wearable clothing item of claim 42 further comprising one or more of

a battery, solar cell, fuel cell, wind power component, crank or other mechanical or renewable or rechargeable or non-renewable power source coupled to the base unit, for use in charging or powering the one or more portable devices or batteries while within or attached to the clothing item.

44. A kiosk or charging station which enables inductive powering and/or charging of portable devices or batteries, comprising:

a base unit, within or on the kiosk or charging station, which includes one or more primary coils generally having a plane or curved surface, wherein each of the primary coils can be activated to generate an inductive field in a direction substantially perpendicular to the plane or curved surface of the coil, for use in powering or charging one or more portable devices or batteries;

one or more features within the base unit that assist in providing position independence of the portable devices or batteries with respect to the base unit, including detecting the presence of one or more portable devices or batteries within an area of the kiosk or charging station, and then selectively activating appropriate one or more primary coils so that the base unit can charge or power the one or more portable devices or batteries so detected.

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

a base unit such as a charger or power supply, which includes a primary coil generally having a plane or curved surface, wherein the primary coil can be activated to generate an inductive field in a direction substantially perpendicular to the plane or curved surface of the coil, for use in powering or charging a portable device or battery;

one or more features within the base unit that assist in providing position independence of the portable devices or batteries on the base unit, including detecting the presence of one or more portable devices or batteries, and then selectively activating the primary coil so that the base unit can charge or power the one or more portable devices or batteries so detected; and

wherein the base unit includes one or more aligning magnets at or near the primary coil, wherein the aligning magnets encourage the general alignment of the primary coil with a receiver coil using corresponding magnets or magnetic material at the receiver coil, or at the portable devices or batteries or case, skin, or other accessory for use therewith.

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

a base unit such as a charger or power supply, which includes a plurality of primary coils generally having a plane or curved surface, wherein each of the primary coils can be activated to generate an inductive field in a direction substantially perpendicular to the plane or curved surface of the coil, for use in powering or charging one or more portable devices or batteries;

one or more features within the base unit that assist in providing position independence of the portable devices or batteries on the base unit, including detecting the presence of one or more portable devices or batteries, and then selectively activating appropriate one or more primary coils so that the base unit can charge or power the one or more portable devices or batteries so detected; and

wherein the plurality of primary coils are provided as a coil mosaic, and wherein the base unit detects the presence of one or more portable devices or batteries by periodically switching on primary coils, monitoring the current flow through the primary coil being switched, using the current flow and/or communication from the receiver in the portable device or battery or its case, skin, or other accessory for use therewith to determine the presence of the one or more portable devices or batteries proximate that primary coil, and then activating the appropriate primary coils.

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

a base unit such as a charger or power supply, which includes one or more primary coils generally having a plane or curved surface, wherein each of the primary coils can be activated to generate an inductive field in a direction substantially perpendicular to the plane or curved surface of the coil, for use in powering or charging one or more portable devices or batteries, and wherein one or more primary coils are free to move within a sector or whole of the base unit; and

one or more features within the base unit that assist in providing position independence of the portable devices or batteries on the base unit, including detecting the presence of one or more portable devices or batteries, and then selectively activating appropriate one or more primary coils so that the base unit can charge or power the one or more portable devices or batteries so detected, including wherein upon placing a portable device or battery or case, skin, or other accessory for use therewith is placed on the base unit, the primary coil is caused to move within its sector or whole of the base unit so that it is better aligned with the portable device or battery or case, skin, or other accessory for use therewith.

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

a base unit such as a charger or power supply, which includes one or more primary coils generally having a plane or curved surface, wherein each of the primary coils can be activated to generate an inductive field in a direction substantially perpendicular to the plane or curved surface of the coil, for use in powering or charging one or more portable devices or batteries simultaneously,

wherein the base unit can provide power to one or more receiver units associated with one or more portable devices or batteries to be powered or charged, each of which receiver units includes a receiver coil, wherein the receiver unit is coupled to or incorporated into a portable device or battery, or case, skin, or other accessory for use therewith, and wherein the receiver unit receives energy inductively via its receiver coil from the primary coil and uses the energy to power or charge the portable device or battery; and

wherein one or more of the base unit and/or the one or more receiver units include additional circuitry and/or coils or antennas to provide further functionalities to the portable device or battery, including exchanging data through one or more of Bluetooth, WiFi, NFC, Felica, WiMax, RFID, Wireless USB or another wireless or optical medium.

49. The system of claim 48, wherein the base unit includes one or more lights, LEDs, displays, or audio signals or messages to help guide a user to place the portable device or battery on a primary coil for maximum reception, to show charging is occurring, to show the device is fully charged and/or provide further functionalities or information.

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

a receiver unit, which includes a receiver coil generally having a planar or curved surface, wherein the receiver unit is coupled to or incorporated into the portable device or battery, or case, skin, or other accessory for use therewith, and wherein the receiver unit is capable of receiving energy from a base unit such as a charger or power supply via an inductive field in a direction substantially perpendicular to the plane or curved surface of its receiver coil, and using the energy to power or charge the portable device or battery; and

wherein one or more of the base unit and/or the receiver unit include additional circuitry and/or coils or antennas to provide further functionalities to the portable device or battery, including exchanging data through one or more of Bluetooth, WiFi, NFC, Felica, WiMax, RFID, Wireless USB or another wireless or optical medium.