Communication across an inductive link with a dynamic load

• US 8,450,877 B2
• Filed: 01/05/2010
• Issued: 05/28/2013
• Est. Priority Date: 01/06/2009
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Baarman, David W., Schwannecke, Joshua K., Mollema, Scott A., Norconk, Matthew J.
• Primary Examiner(s): Amrany, Adi
• Application Number:
  US12/652,061
• Publication Number:
  US 20100171369A1
• Time in Patent Office: 1,239 Days
• Field of Search: 307/104
• US Class Current: 307/104
• CPC Class Codes: G06K 19/0707 the arrangement being capable of collecting energy from external energy sources, e.g. thermocouples, vibration, electromagnetic radiation G06K19/0702 takes precedence
• CPC Class Codes: G06K 19/0712 the arrangement being capable of triggering distinct operating modes or functions dependent on the strength of an energy or interrogation field in the proximity of the record carrier active means for hindering electromagnetic reading or writing G06K19/07336
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: H02J 50/10 using inductive coupling
• 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: H04B 5/26 using coils
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

The present invention provides a load used for communication in a remote device having a dynamic communication load configuration. In one embodiment, the dynamic communication load configuration vanes as a function of a characteristic of power in the remote device. The remote device toggles between load configurations to communicate with the inductive power supply. A sensor in the remote device detects a characteristic of power in the remote device and configures the communication load based on the sensor output. In another embodiment, the remote device adjusts the dynamic communication load configuration in the remote device in response to a failure to receive a response from the inductive power supply.

Claims

1. A contactless power supply system comprising:

an inductive power supply and a remote device, said remote device capable of inductively receiving power from said power supply via an inductive coupling;

wherein said inductive power supply includes;

a primary for inductively transferring power to said remote device;

a primary circuit operatively coupled to said primary, said primary circuit

     1) generating an output indicative of a characteristic of power being affected by a characteristic of said remote device reflected through said inductive coupling and

     2) controlling operation of said inductive power supply in response to said output; and

wherein said remote device includes;

a target load capable of utilizing said power provided by said inductive power supply;

a sensor for detecting a characteristic of power in said remote device;

a communication load capable of being configured in at least three different communication load states each having a different value, and wherein;

a first communication load state of said at least three different communication load states has a first value, said first communication load state enabling current to pass through said target load and said communication load;

a second communication load state of said at least three different communication load states has a second value, said second communication load state enabling current to pass through said target load and said communication load, said first value and said second value being different;

a third communication load state of said at least three different communication load states is an off state in which current passes through said target load and effectively bypasses said communication load; and

said communication load capable of being toggled between said first and said second communication load states to communicate with said inductive power supply; and

a controller programmed to

     1) configure said communication load in one or more of said at least three different communication load states based on output from said sensor; and

     2) based on a binary data stream, toggle said communication load between said first communication load state to create a high signal and said second communication load state to create a low signal to communicate with said inductive power supply.

2. The contactless power supply system of claim 1 wherein said at least three different communication load states include at least one of said communication load including a resistor, said communication load including a diode, said communication load including a capacitor, said communication load including an inductor, said communication load including a dynamic load, and said communication load including a device with a constant voltage drop.

3. The contactless power supply system of claim 1 wherein said controller is programmed to configure said communication load to include a first resistance when said output from said sensor is below a threshold and wherein said controller is programmed to configure said communication load to include a second resistance when said output from said sensor is above said threshold. Zone Name:

OCRZone

4. The contactless power supply system of claim 1 wherein said controller is programmed to configure said communication load in one of said at least three communication load states when said output from said sensor is below a threshold and wherein said controller is programmed to configure said communication load in a different communication load state when said output from said sensor is above said threshold.

5. The contactless power supply system of claim 1 wherein said controller is programmed to switch between different communication load states by increasing a resistance of said communication load until a message is received by said inductive power supply.

6. The contactless power supply system of claim 1 wherein said communication load includes first and second communication resistors, and wherein one of said at least three communication load states includes said first communication resistor and another of said at least three communication load states includes said first and second communication resistors.

7. The contactless power supply system of claim 1 wherein said at least three communication states includes said off state and at least two working states, wherein said communication load is toggled between said off state and one of said at least two working states to communicate with said inductive power supply.

8. A remote device for receiving power from an inductive power supply, said remote device comprising:

a target load capable of utilizing said power provided by said inductive power supply;

a sensor for detecting a characteristic of power in said remote device;

a communication load capable of being configured in at least three different communication load states each having a different value, and wherein;

a first communication load state of said at least three different communication load states has a first value, said first communication load state enabling current to pass through said target load and said communication load;

a second communication load state of said at least three different communication load states has a second value, said second communication load state enabling current to pass through said target load and said communication load, said first value and said second value being different;

a third communication load state of said at least three different communication load states is an off state in which current passes through said target load and effectively bypasses said communication load; and

said communication load is capable of being toggled between said first and said second communication load states to communicate with said inductive power supply; and

a controller programmed to

     1) configure said communication load in one or more of said at least three different communication load states based on output from said sensor; and

2) based on a binary data stream, toggle said communication load between said first communication load state to create a high signal and said second communication load state to create a low signal to communicate with said inductive power supply.

9. The remote device of claim 8 wherein said at least three different communication load states include at least one of said communication load including a resistor, said communication load including a diode, said communication load including a capacitor, said communication load including an inductor, said communication load including a dynamic load, and said communication load including a device with a constant voltage drop.

10. The remote device of claim 8 wherein said controller is programmed to configure said communication load to include a first resistance when said output from said sensor is below a threshold and wherein said controller is programmed to configure said communication load to include a second resistance when said output from said sensor is above said threshold.

11. The remote device of claim 8 wherein said controller is programmed to configure said communication load in one of said at least three communication load states when said output from said sensor is below a threshold and wherein said controller is programmed to configure said communication load in a different communication load state when said output from said sensor is above said threshold.

12. The remote device of claim 8 wherein said controller is programmed to switch between different communication load states by increasing a resistance of said communication load until a message is received by said inductive power supply.

13. A method for communicating from a remote device and an inductive power supply comprising:

providing a communication load configurable in at least three communication load states, the at least three communication load states including a first communication load state, a second communication load state, and a third communication load state, the third communication load state being an off state;

receiving power from the inductive power supply;

measuring a characteristic of power received by the remote device;

determining a first configuration of the communication load for the first communication load state based on the characteristic of power measured, the first configuration of the communication load being different from a second configuration of the communication load for the second communication load state;

communicating with the inductive power supply by, based on a binary data stream, toggling between the first communication load state to create a high signal and the second communication load state to create a low signal.

14. The method of claim 13 wherein determining a first configuration of the communication load for the first communication load state includes determining the first a working communication load state based on an amount of power measured and comparing the amount of power measured to a threshold.

15. The method of claim 13 wherein determining a first configuration of the communication load for the first communication load state based on the characteristic of power measured includes determining the first communication load state to be a specific percentage greater than a delivered amount of power in another communication load state such that toggling between the first and second communication load states allows the reflected impedance to be distinguished as communication instead of noise.

16. The method of claim 13 wherein determining a first configuration of the communication load for the first communication load state based on the characteristic of power measured includes increasing a resistance in the first communication load state until a message is received by the inductive power supply.

17. The method of claim 13 wherein determining a first configuration of the communication load for the first a working communication load state based on the characteristic of power measured includes determining the first a working communication load state that reduces an amount of power lost due to communication with the inductive power supply using a static load configuration.

18. The method of claim 13 wherein determining a first configuration of the communication load for the first communication load state based on the characteristic of power measured includes determining first communication load state that creates a sufficient difference in reflected impedance so that the inductive power supply can receive communication from the remote device.

19. The method of claim 18 wherein the another of the at least three communication load states is the off state.

20. The method of claim 13 wherein the another of the at least three communication load states is the off state, and wherein communicating with the inductive power supply includes toggling between the working communication load state and the off state.

21. A method for communicating from a remote device to an inductive power supply comprising:

providing a communication load configurable in at least three communication load states, one of the at least three communication load states being an off state;

receiving power from the inductive power supply;

determining first working communication load state and a second working communication load state in the remote device, the first and second working communication load states state being selected from the at least three communication load states other than the off state, the first and second working communication load states having different communication load configurations;

transmitting a communication to the inductive power supply by, based on a binary data stream, toggling the communication load between the first determined working communication load state to create a high signal and the second determined working communication load state to create a low signal;

waiting for a response from the inductive power supply;

adjusting the first determined working communication load state in the remote device in response to a failure to receive the response, the adjusted first working communication load state being selected from the at least three communication load states;

re-transmitting the communication to the inductive power supply by toggling the communication load between the adjusted first working communication load state and another of the at least three communication load states.

22. A remote device for receiving power from an inductive power supply via an inductive coupling, said remote device comprising:

a secondary capable of receiving power from the inductive power supply via the inductive coupling;

a target load capable of utilizing said power received by said secondary;

a communication load capable of being configured in at least three communication load states, said at least three communication load states including an off state and at least two working communication states, said at least two working communication states including a first working communication state and a second working communication state, said communication load in said first working communication state being configured differently from said communication load in said second working communication state;

a controller coupled to said communication load, said controller programmed to communicate with the inductive power supply via the inductive coupling by, based on a binary data stream, toggling said communication load between said first working communication state to create a high signal and said second communication state to create a low signal.

23. The remote device as claimed in claim 22 wherein said controller is further programmed to communicate with the inductive power supply by toggling between one of said at least two working states and said off state.

24. The remote device as claimed in claim 22 wherein:

said communication load includes first and second communication elements;

said remote device further includes a first switch coupled to said first communication element and a second switch coupled to said second communication element;

said first switch is capable of selectively configuring said communication load in said first working communication state of said working communication states by shunting power received in said secondary through said first communication element; and

said second switch is capable of selectively configuring said communication load in said second working state of said working communication states by shunting power received in said secondary through said second communication element.

25. The remote device as claimed in claim 24 wherein:

said controller is coupled to said first and second switches;

said controller is programmed to communicate with the inductive power supply by selectively activating said first switch and said second switch to toggle between said first working communication state and said off second working communication state.

26. The remote device as claimed in claim 25 wherein said remote device further comprises a sensor for detecting a characteristic of power in said secondary, and wherein said controller determines a value of said communication load in said at least two working communication states based on said sensed characteristic of power.

27. The remote device as claimed in claim 24 wherein said controller is programmed to configure said communication load in said off state by opening said first and second switches to prevent said first and second communication elements from shunting power.

28. The remote device as claimed in claim 24 wherein said first communication element is a first resistor and said second communication element is a second resistor.