Power system

• US 8,446,046 B2
• Filed: 10/02/2009
• Issued: 05/21/2013
• Est. Priority Date: 10/03/2008
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Fells, Julian Andrew John, Baarman, David W.
• Primary Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US12/572,296
• Publication Number:
  US 20100084918A1
• Time in Patent Office: 1,327 Days
• Field of Search: 307/104
• US Class Current: 307/104
• CPC Class Codes: G01V 3/10 using induction coils
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• 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 7/00045 Authentication, i.e. circuits for checking compatibility between one component, e.g. a battery or a battery charger, and another component, e.g. a power source
• CPC Class Codes: H02M 3/28 using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

The present invention provides methods and apparatus for reducing power consumption. One method includes detecting the presence of an object, identifying whether the object is a valid device and restricting power if its not a valid device. Another method includes temporarily applying a low amount of power to the primary unit to detect a load, supplying more power to determine if its a valid secondary device, and restricting power if its not. An apparatus for reducing power consumption includes two power inputs, where the lower power input powers a sense circuit. A switch selectively decouples the higher power input from the primary subcircuit during detection mode and couples the higher power input to the primary subcircuit during power supply mode.

Claims

1. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

detecting presence of an object within proximity of said primary unit;

sending a pulse of power to said object in response to detecting presence of said object within proximity of said primary unit;

determining whether a valid secondary device is present in proximity to said primary unit in response to sending said pulse of power to said object;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

further including in response to determining that a valid secondary device is present, determining whether said valid secondary device desires power, and in response to a determination that no present valid secondary devices desire power, restricting power supplied to said primary unit.

2. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

detecting presence of an object within proximity of said primary unit;

sending a pulse of power to said object in response to detecting presence of said object within proximity of said primary unit;

determining whether a valid secondary device is present in proximity to said primary unit in response to sending said pulse of power to said object;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said pulse of power includes a communication signal.

3. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

detecting presence of an object within proximity of said primary unit;

sending a pulse of power to said object in response to detecting presence of said object within proximity of said primary unit;

determining whether a valid secondary device is present in proximity to said primary unit in response to sending said pulse of power to said object;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said pulse of power is sufficient to enable communication from a secondary device.

4. The method for reducing power consumption in said primary unit of claim 3 wherein said detecting uses a lower amount of power than said pulse of power.

5. The method for reducing power consumption in said primary unit of claim 3 wherein said detecting includes at least one of detecting a change in magnetic field indicative of presence of an object, detecting a change in capacitance, detecting a change in mass, detecting a change in motion indicative of presence of an object, detecting a change in pressure indicative of presence of an object, and detecting a change in light level indicative of presence of an object.

6. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

detecting presence of an object within proximity of said primary unit;

sending a pulse of power to said object in response to detecting presence of said object within proximity of said primary unit;

determining whether a valid secondary device is present in proximity to said primary unit in response to sending said pulse of power to said object;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit;

receiving communication from said secondary device indicative of the status of said secondary device; and

wherein said determining whether a valid secondary device is present is at least in part a function of said status of said secondary device.

7. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

detecting presence of an object within proximity of said primary unit;

sending a pulse of power to said object in response to detecting presence of said object within proximity of said primary unit;

determining whether a valid secondary device is present in proximity to said primary unit in response to sending said pulse of power to said object;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said detecting presence of an object includes detecting at least one of a change in number of objects in proximity to said primary unit; and

a change in position of one or more objects in proximity to said primary unit.

8. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

detecting presence of an object within proximity of said primary unit;

sending a pulse of power to said object in response to detecting presence of said object within proximity of said primary unit;

determining whether a valid secondary device is present in proximity to said primary unit in response to sending said pulse of power to said object;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said detecting presence of an object and said sending said pulse of power utilize power from different power sources.

9. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

detecting presence of an object within proximity of said primary unit;

sending a pulse of power to said object in response to detecting presence of said object within proximity of said primary unit;

determining whether a valid secondary device is present in proximity to said primary unit in response to sending said pulse of power to said object;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said detecting utilizes power from an energy storage element; and

in response to determining that a valid secondary device is present, supplying power to said primary unit sufficient to transfer power to said secondary device in order to at least one of charge a secondary device battery and directly power said secondary device.

10. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

detecting presence of an object within proximity of said primary unit;

sending a pulse of power to said object in response to detecting presence of said object within proximity of said primary unit;

determining whether a valid secondary device is present in proximity to said primary unit in response to sending said pulse of power to said object;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said detecting utilizes power from an energy storage element; and

in response to determining that a valid secondary device is present, both recharging said energy storage element and supplying power to said primary unit sufficient to transfer power to said secondary device in order to at least one of charge a secondary device battery and directly power said secondary device.

11. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

detecting presence of an object within proximity of said primary unit;

sending a pulse of power to said object in response to detecting presence of said object within proximity of said primary unit;

determining whether a valid secondary device is present in proximity to said primary unit in response to sending said pulse of power to said object;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein as a function of said determination of whether a valid secondary device is present, communicating with an auxiliary unit to control the power supplied to said auxiliary unit.

12. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

applying a pulse of low power to said primary unit;

detecting whether there is a draw of power in said primary unit indicative of a load within proximity to said primary unit;

upon detecting a load, supplying power to said primary unit at a higher level than said pulse of low power;

determining whether a valid secondary device is present in proximity to said primary unit in response to said supply of power at said higher level;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

further including in response to determining that a valid secondary device is present, determining whether said valid secondary device desires power, and in response to a determination that no present valid secondary devices desire power, restricting power supplied to said primary unit.

13. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

applying a pulse of low power to said primary unit;

detecting whether there is a draw of power in said primary unit indicative of a load within proximity to said primary unit;

upon detecting a load, supplying power to said primary unit at a higher level than said pulse of low power;

determining whether a valid secondary device is present in proximity to said primary unit in response to said supply of power at said higher level;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said applying the pulse of low power to said primary unit generates a sufficiently small magnetic field such that said secondary device cannot supply sufficient power to its circuitry to allow communication with said primary unit.

14. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

applying a pulse of low power to said primary unit;

detecting whether there is a draw of power in said primary unit indicative of a load within proximity to said primary unit;

upon detecting a load, supplying power to said primary unit at a higher level than said pulse of low power;

determining whether a valid secondary device is present in proximity to said primary unit in response to said supply of power at said higher level;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said power to said primary unit at said higher level than said pulse of low power includes a communication signal.

15. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

applying a pulse of low power to said primary unit;

detecting whether there is a draw of power in said primary unit indicative of a load within proximity to said primary unit;

upon detecting a load, supplying power to said primary unit at a higher level than said pulse of low power;

determining whether a valid secondary device is present in proximity to said primary unit in response to said supply of power at said higher level;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said power to said primary unit at said higher level than said pulse of low power is sufficient to enable communication from a secondary device.

16. The method for reducing power consumption in said primary unit of claim 15 wherein in response to a determination that a valid secondary device is present, supplying power to said primary unit to transfer power to said valid secondary device.

17. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

applying a pulse of low power to said primary unit;

detecting whether there is a draw of power in said primary unit indicative of a load within proximity to said primary unit;

upon detecting a load, supplying power to said primary unit at a higher level than said pulse of low power;

determining whether a valid secondary device is present in proximity to said primary unit in response to said supply of power at said higher level;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit;

receiving communication from said secondary device indicative of the status of said secondary device; and

wherein said determining whether a valid secondary device is present is at least in part a function of said status of said secondary device.

18. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

applying a pulse of low power to said primary unit;

detecting whether there is a draw of power in said primary unit indicative of a load within proximity to said primary unit;

upon detecting a load, supplying power to said primary unit at a higher level than said pulse of low power;

determining whether a valid secondary device is present in proximity to said primary unit in response to said supply of power at said higher level;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit;

wherein said detecting presence of a load includes detecting at least one of

a change in number of objects in proximity to said primary unit; and

a change in position of one or more objects in proximity to said primary unit.

19. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

applying a pulse of low power to said primary unit;

detecting whether there is a draw of power in said primary unit indicative of a load within proximity to said primary unit;

upon detecting a load, supplying power to said primary unit at a higher level than said pulse of low power;

determining whether a valid secondary device is present in proximity to said primary unit in response to said supply of power at said higher level;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said pulse of low power and said higher level of power utilize power from different power sources.

20. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

applying a pulse of low power to said primary unit;

detecting whether there is a draw of power in said primary unit indicative of a load within proximity to said primary unit;

upon detecting a load, supplying power to said primary unit at a higher level than said pulse of low power;

determining whether a valid secondary device is present in proximity to said primary unit in response to said supply of power at said higher level;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said pulse of low power utilizes power from an energy storage element; and

in response to determining that a valid secondary device is present, supplying power to said primary unit sufficient to transfer power to said secondary device in order to at least one of charge a secondary device battery and directly power said secondary device.

21. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

applying a pulse of low power to said primary unit;

detecting whether there is a draw of power in said primary unit indicative of a load within proximity to said primary unit;

upon detecting a load, supplying power to said primary unit at a higher level than said pulse of low power;

determining whether a valid secondary device is present in proximity to said primary unit in response to said supply of power at said higher level;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein said pulse of low power utilizes power from an energy storage element; and

in response to determining that a valid secondary device is present, both recharging said energy storage element and supplying power to said primary unit sufficient to transfer power to said secondary device in order to at least one of charge a secondary device battery and directly power said secondary device.

22. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

applying a pulse of low power to said primary unit;

detecting whether there is a draw of power in said primary unit indicative of a load within proximity to said primary unit;

upon detecting a load, supplying power to said primary unit at a higher level than said pulse of low power;

determining whether a valid secondary device is present in proximity to said primary unit in response to said supply of power at said higher level;

in response to a determination that a valid secondary device is not present, restricting power supplied to said primary unit; and

wherein as a function of said determination of whether a valid secondary device is present, communicating with an auxiliary unit to control the power supplied to said auxiliary unit.

23. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a first power input for supplying power during a power supply mode;

a second power input for supplying power during a detection mode, wherein said second power input provides less power than said first power input;

a primary subcircuit capable of transferring power to a secondary device;

a switch operable to selectively couple said first power input to said primary subcircuit;

a sense circuit for detecting the presence of an object within proximity of the primary unit, said sense circuit powered by said second power input, wherein said sense circuit operates said switch to decouple said primary subcircuit from said first power input during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode;

wherein said sense circuit includes;

an impedance element;

an oscillator coupled to said impedance element, said oscillator converting said second power input to AC power;

a peak detector for detecting a peak voltage across said impedance element; and

a microprocessor programmed to periodically read the value of the peak detector, detect a change in impedance, and activate said switch to selectively couple said first power input to said primary circuit.

24. The primary unit of claim 23 further including a switch to selectively connect said peak detector and said oscillator to said second power input for the duration of a peak detection measurement.

25. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a first power input for supplying power during a power supply mode;

a second power input for supplying power during a detection mode, wherein said second power input provides less power than said first power input;

a primary subcircuit capable of transferring power to a secondary device;

a switch operable to selectively couple said first power input to said primary subcircuit;

a sense circuit for detecting the presence of an object within proximity of the primary unit, said sense circuit powered by said second power input, wherein said sense circuit operates said switch to decouple said primary subcircuit from said first power input during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode;

wherein said sense circuit includes;

an oscillator circuit selectably coupled to a primary coil located within said primary subcircuit; and

a microprocessor programmed to measure the frequency of said oscillator circuit.

26. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a first power input for supplying power during a power supply mode;

a second power input for supplying power during a detection mode, wherein said second power input provides less power than said first power input;

a primary subcircuit capable of transferring power to a secondary device;

a switch operable to selectively couple said first power input to said primary subcircuit;

a sense circuit for detecting the presence of an object within proximity of the primary unit, said sense circuit powered by said second power input, wherein said sense circuit operates said switch to decouple said primary subcircuit from said first power input during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode; and

wherein said impedance element includes a primary coil located in said subcircuit for transferring power to a secondary device, and said sense circuit includes a switch to selectively connect said primary coil to said sense circuit for the duration of a peak detection measurement.

27. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a first power input for supplying power during a power supply mode;

a second power input for supplying power during a detection mode, wherein said second power input provides less power than said first power input;

a primary subcircuit capable of transferring power to a secondary device;

a switch operable to selectively couple said first power input to said primary subcircuit;

a sense circuit for detecting the presence of an object within proximity of the primary unit, said sense circuit powered by said second power input, wherein said sense circuit operates said switch to decouple said primary subcircuit from said first power input during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode; and

wherein said sense circuit includes a microprocessor with a watchdog timer that enables the microprocessor to only wake up during a sense circuit measurement.

28. The primary unit of claim 27 wherein said sense circuit includes at least one of a hall sensor, a reed switch, a motion sensor, a switch, a capacitance sensor, a mass sensor, a pressure sensor, and a light sensor.

29. The primary unit of claim 27 wherein said sense circuit is programmed to control a switch operable to selectively couple said first power input to an auxiliary unit.

30. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a first power input for supplying power during a power supply mode;

a second power input for supplying power during a detection mode, wherein said second power input provides less power than said first power input;

a primary subcircuit capable of transferring power to a secondary device;

a switch operable to selectively couple said first power input to said primary subcircuit;

a sense circuit for detecting the presence of an object within proximity of the primary unit, said sense circuit powered by said second power input, wherein said sense circuit operates said switch to decouple said primary subcircuit from said first power input during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode;

a receiver for receiving communication from said secondary device indicative of the status of said secondary device; and

wherein said identification unit determines whether said secondary device is valid at least in part as a function of said status of said secondary device.

31. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a first power input for supplying power during a power supply mode;

a second power input for supplying power during a detection mode, wherein said second power input provides less power than said first power input;

a primary subcircuit capable of transferring power to a secondary device;

a switch operable to selectively couple said first power input to said primary subcircuit;

a sense circuit for detecting the presence of an object within proximity of the primary unit, said sense circuit powered by said second power input, wherein said sense circuit operates said switch to decouple said primary subcircuit from said first power input during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode; and

wherein said primary subcircuit includes an identification unit, and wherein in response to said coupling of said first power input to said primary subcircuit, said identification unit is programmed to identify whether a valid secondary device is present within proximity of the primary unit, and in response to a determination that a valid secondary device is not present power to said primary subcircuit is restricted by operating said switch to disconnect said primary subcircuit from said first power input.

32. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a first power input for supplying power during a power supply mode;

a second power input for supplying power during a detection mode, wherein said second power input provides less power than said first power input;

a primary subcircuit capable of transferring power to a secondary device;

a switch operable to selectively couple said first power input to said primary subcircuit;

a sense circuit for detecting the presence of an object within proximity of the primary unit, said sense circuit powered by said second power input, wherein said sense circuit operates said switch to decouple said primary subcircuit from said first power input during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode; and

wherein said primary subcircuit includes an identification unit, and wherein in response to said coupling of said first power input to said primary subcircuit, said identification unit is programmed to identify whether said secondary device desires power, and in response to a determination that no secondary device desires power, power to said primary subcircuit is restricted by operating said switch to disconnect said primary subcircuit from said first power input.

33. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a first power input for supplying power during a power supply mode;

a second power input for supplying power during a detection mode, wherein said second power input provides less power than said first power input;

a primary subcircuit capable of transferring power to a secondary device;

a switch operable to selectively couple said first power input to said primary subcircuit;

a sense circuit for detecting the presence of an object within proximity of the primary unit, said sense circuit powered by said second power input, wherein said sense circuit operates said switch to decouple said primary subcircuit from said first power input during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode; and

wherein said second power input comprises an energy storage element; and

wherein said energy storage element is recharged while said first power input is coupled to said primary subcircuit.

34. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a first power input for supplying power during a power supply mode;

a second power input for supplying power during a detection mode, wherein said second power input provides less power than said first power input;

a primary subcircuit capable of transferring power to a secondary device;

a switch operable to selectively couple said first power input to said primary subcircuit;

a sense circuit for detecting the presence of an object within proximity of the primary unit, said sense circuit powered by said second power input, wherein said sense circuit operates said switch to decouple said primary subcircuit from said first power input during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode; and

wherein said second power input comprises an energy storage element.

35. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a power supply circuit for wirelessly transferring power to a secondary device during a power supply mode;

a detection circuit for detecting the presence of an object within proximity of the primary unit during a detection mode;

an identification unit for identifying whether a detected object is a valid secondary device during an identification mode;

a switch operable to selectively couple and decouple said power supply circuit to a supply of power;

a control circuit located within the primary unit programmed to alternately operate said primary unit in said detection mode, said identification mode, and said power supply mode, wherein said control circuit operates said switch to decouple said power supply circuit from said supply of power during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode; and

wherein said identification unit, during said identification mode determines whether said detected valid secondary device desires power.

36. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a power supply circuit for wirelessly transferring power to a secondary device during a power supply mode;

a detection circuit for detecting the presence of an object within proximity of the primary unit during a detection mode;

an identification unit for identifying whether a detected object is a valid secondary device during an identification mode;

a switch operable to selectively couple and decouple said power supply circuit to a supply of power;

a control circuit located within the primary unit programmed to alternately operate said primary unit in said detection mode, said identification mode, and said power supply mode, wherein said control circuit operates said switch to decouple said power supply circuit from said supply of power during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode;

wherein said detection mode includes;

restricting the supply of power to the power supply circuit by opening said switch;

detecting the presence of an object within proximity of the primary unit;

upon detecting the presence of an object within proximity of the primary unit, entering a different mode; and

wherein said power supply mode includes;

supplying power to the primary unit by closing said switch;

identifying if there is a secondary device in proximity;

remaining in the power supply or entering the detection mode in dependence upon the identification.

37. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a power supply circuit for wirelessly transferring power to a secondary device during a power supply mode;

a detection circuit for detecting the presence of an object within proximity of the primary unit during a detection mode;

an identification unit for identifying whether a detected object is a valid secondary device during an identification mode;

a switch operable to selectively couple and decouple said power supply circuit to a supply of power;

a control circuit located within the primary unit programmed to alternately operate said primary unit in said detection mode, said identification mode, and said power supply mode, wherein said control circuit operates said switch to decouple said power supply circuit from said supply of power during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode;

wherein said detection circuit includes;

an impedance element;

an oscillator coupled to said impedance element, said oscillator converting said second power input to AC power;

a peak detector for detecting a peak voltage across said impedance element; and

a microprocessor programmed to periodically read the value of the peak detector, detect a change in impedance, and activate said switch to selectively couple said first power input to said primary circuit.

38. The primary unit of claim 37 wherein said impedance element includes a primary coil located in said power supply circuit for transferring power to a secondary device, and said sense circuit includes a switch to selectively connect said primary coil to said sense circuit for the duration of a peak detection measurement.

39. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a power supply circuit for wirelessly transferring power to a secondary device during a power supply mode;

a detection circuit for detecting the presence of an object within proximity of the primary unit during a detection mode;

an identification unit for identifying whether a detected object is a valid secondary device during an identification mode;

a switch operable to selectively couple and decouple said power supply circuit to a supply of power;

a control circuit located within the primary unit programmed to alternately operate said primary unit in said detection mode, said identification mode, and said power supply mode, wherein said control circuit operates said switch to decouple said power supply circuit from said supply of power during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode;

wherein said detection circuit includes;

an oscillator circuit selectably coupled to a primary coil located within said primary subcircuit; and

a microprocessor programmed to measure the frequency of said oscillator circuit.

40. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a power supply circuit for wirelessly transferring power to a secondary device during a power supply mode;

a detection circuit for detecting the presence of an object within proximity of the primary unit during a detection mode;

an identification unit for identifying whether a detected object is a valid secondary device during an identification mode;

a switch operable to selectively couple and decouple said power supply circuit to a supply of power;

a control circuit located within the primary unit programmed to alternately operate said primary unit in said detection mode, said identification mode, and said power supply mode, wherein said control circuit operates said switch to decouple said power supply circuit from said supply of power during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode; and

further including a switch to selectively connect said peak detector and said oscillator to said second power input for the duration of a peak detection measurement.

41. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a power supply circuit for wirelessly transferring power to a secondary device during a power supply mode;

a detection circuit for detecting the presence of an object within proximity of the primary unit during a detection mode;

an identification unit for identifying whether a detected object is a valid secondary device during an identification mode;

a switch operable to selectively couple and decouple said power supply circuit to a supply of power;

a control circuit located within the primary unit programmed to alternately operate said primary unit in said detection mode, said identification mode, and said power supply mode, wherein said control circuit operates said switch to decouple said power supply circuit from said supply of power during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode; and

wherein said detection circuit includes a microprocessor with a watchdog timer that enables the microprocessor to only wake up during a sense circuit measurement.

42. The primary unit of claim 41 wherein said detection circuit includes at least one of a hall sensor, a reed switch, a motion sensor, a switch, a pressure sensor, and a light sensor.

43. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a power supply circuit for wirelessly transferring power to a secondary device during a power supply mode;

a detection circuit for detecting the presence of an object within proximity of the primary unit during a detection mode;

an identification unit for identifying whether a detected object is a valid secondary device during an identification mode;

a switch operable to selectively couple and decouple said power supply circuit to a supply of power;

a control circuit located within the primary unit programmed to alternately operate said primary unit in said detection mode, said identification mode, and said power supply mode, wherein said control circuit operates said switch to decouple said power supply circuit from said supply of power during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode;

a receiver capable of receiving communication from said secondary device indicative of a status of said secondary device; and

wherein said primary unit includes an identification circuit that determines whether said secondary device is valid at least in part as a function of said status of said secondary device.

44. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a power supply circuit for wirelessly transferring power to a secondary device during a power supply mode;

a detection circuit for detecting the presence of an object within proximity of the primary unit during a detection mode;

an identification unit for identifying whether a detected object is a valid secondary device during an identification mode;

a switch operable to selectively couple and decouple said power supply circuit to a supply of power;

a control circuit located within the primary unit programmed to alternately operate said primary unit in said detection mode, said identification mode, and said power supply mode, wherein said control circuit operates said switch to decouple said power supply circuit from said supply of power during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode; and

wherein said primary unit includes an identification unit, and wherein in response to said detection circuit detecting the presence of an object within proximity of the primary unit, said identification unit is programmed to

identify whether a valid secondary device is present within proximity of the primary unit, and

in response to a failure to identify a valid secondary device, said control circuit operates said switch to decouple said power supply circuit from said supply of power.

45. A primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said primary unit comprising:

a power supply circuit for wirelessly transferring power to a secondary device during a power supply mode;

a detection circuit for detecting the presence of an object within proximity of the primary unit during a detection mode;

an identification unit for identifying whether a detected object is a valid secondary device during an identification mode;

a switch operable to selectively couple and decouple said power supply circuit to a supply of power;

a control circuit located within the primary unit programmed to alternately operate said primary unit in said detection mode, said identification mode, and said power supply mode, wherein said control circuit operates said switch to decouple said power supply circuit from said supply of power during said detection mode, wherein said primary unit consumes less power during said detection mode than during said power supply mode; and

wherein said primary unit takes power from a mains power source during power supply mode and takes power from a secondary power source during detection mode.

46. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

providing a primary unit capable of selectively operating in a detection mode, an identification mode, and a power supply mode;

detecting presence of an object within proximity of said primary unit during said detection mode, wherein said detection mode includes;

restricting the supply of power to at least a portion of the primary unit;

detecting presence of an object within proximity of the primary unit;

in dependence upon said detecting, either staying in said detection mode or entering said identification mode;

identifying said object during said identification mode, wherein said identification mode includes;

identifying whether said detected object is a valid secondary device;

upon identifying a valid secondary device entering said power supply mode;

upon failing to identify a valid secondary device entering said detection mode;

supplying power wirelessly to the secondary device during said power supply mode, wherein said power supply mode includes;

supplying power to said primary unit at a higher level than during said detection mode, said higher level of power sufficient for said primary unit to function as a wireless power supply;

wherein said identification mode includes;

receiving communication from said secondary device indicative of the status of said secondary device; and

wherein said identifying whether said detected object is a valid secondary device is at least in part a function of said status of said secondary device.

47. The method for reducing power consumption in said primary unit of claim 46 wherein said detecting includes at least one of detecting a change in magnetic field indicative of presence of an object, detecting a change in capacitance, detecting a change in mass, detecting a change in motion indicative of presence of an object, detecting a change in pressure indicative of presence of an object, and detecting a change in light level indicative of presence of an object.

48. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

providing a primary unit capable of selectively operating in a detection mode, an identification mode, and a power supply mode;

detecting presence of an object within proximity of said primary unit during said detection mode, wherein said detection mode includes;

restricting the supply of power to at least a portion of the primary unit;

detecting presence of an object within proximity of the primary unit;

in dependence upon said detecting, either staying in said detection mode or entering said identification mode;

identifying said object during said identification mode, wherein said identification mode includes;

identifying whether said detected object is a valid secondary device;

upon identifying a valid secondary device entering said power supply mode;

upon failing to identify a valid secondary device entering said detection mode;

supplying power wirelessly to the secondary device during said power supply mode, wherein said power supply mode includes;

supplying power to said primary unit at a higher level than during said detection mode, said higher level of power sufficient for said primary unit to function as a wireless power supply; and

wherein said detecting presence of an object includes detecting at least one of a change in number of objects in proximity to said primary unit; and

a change in position of one or more objects in proximity to said primary unit.

49. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

providing a primary unit capable of selectively operating in a detection mode, an identification mode, and a power supply mode;

detecting presence of an object within proximity of said primary unit during said detection mode, wherein said detection mode includes;

restricting the supply of power to at least a portion of the primary unit;

detecting presence of an object within proximity of the primary unit;

in dependence upon said detecting, either staying in said detection mode or entering said identification mode;

identifying said object during said identification mode, wherein said identification mode includes;

identifying whether said detected object is a valid secondary device;

upon identifying a valid secondary device entering said power supply mode;

upon failing to identify a valid secondary device entering said detection mode;

supplying power wirelessly to the secondary device during said power supply mode, wherein said power supply mode includes;

supplying power to said primary unit at a higher level than during said detection mode, said higher level of power sufficient for said primary unit to function as a wireless power supply; and

wherein said primary unit uses power from different power sources during detection mode and said power supply mode.

50. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

providing a primary unit capable of selectively operating in a detection mode, an identification mode, and a power supply mode, detecting presence of an object within proximity of said primary unit during said detection mode, wherein said detection mode includes;

restricting the supply of power to at least a portion of the primary unit;

detecting presence of an object within proximity of the primary unit;

in dependence upon said detecting, either staying in said detection mode or entering said identification mode;

identifying said object during said identification mode, wherein said identification mode includes;

identifying whether said detected object is a valid secondary device;

upon identifying a valid secondary device entering said power supply mode;

upon failing to identify a valid secondary device entering said detection mode;

supplying power wirelessly to the secondary device during said power supply mode, wherein said power supply mode includes;

supplying power to said primary unit at a higher level than during said detection mode, said higher level of power sufficient for said primary unit to function as a wireless power supply; and

wherein during said detection mode power said primary unit uses power from an energy storage element;

and said power supply mode includes recharging said energy storage element.

51. A method for reducing power consumption in a primary unit capable of transferring power to a secondary device, said secondary device separable from said primary unit, said method comprising the steps of:

providing a primary unit capable of selectively operating in a detection mode, an identification mode, and a power supply mode;

detecting presence of an object within proximity of said primary unit during said detection mode, wherein said detection mode includes;

restricting the supply of power to at least a portion of the primary unit;

detecting presence of an object within proximity of the primary unit;

in dependence upon said detecting, either staying in said detection mode or entering said identification mode;

identifying said object during said identification mode, wherein said identification mode includes;

identifying whether said detected object is a valid secondary device;

upon identifying a valid secondary device entering said power supply mode;

upon failing to identify a valid secondary device entering said detection mode;

supplying power wirelessly to the secondary device during said power supply mode, wherein said power supply mode includes;

supplying power to said primary unit at a higher level than during said detection mode, said higher level of power sufficient for said primary unit to function as a wireless power supply; and

wherein during said detection mode said primary unit uses power from an energy storage element.