SYSTEMS AND METHODS FOR DETECTING DATA COMMUNICATION OVER A WIRELESS POWER LINK

• US 20110204711A1
• Filed: 01/24/2011
• Published: 08/25/2011
• Est. Priority Date: 01/25/2010
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Amistadi, Jason L., Blaha, Mark A., Zeik, Andrew C., Liff, Dale R., Gruich, Robert D., Baarman, David W., Norconk, Matthew J., Schwannecke, Joshua K., Mollema, Scott A.
• Granted Patent: US 9,154,002 B2
• Time in Patent Office: Days
• US Class Current: 307/3
• CPC Class Codes: H02J 50/12 of the resonant type
• 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 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/70 specially adapted for specific purposes
• 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

A wireless power supply system that detects communications in the input power to the switching circuit. In this aspect of the invention, the wireless power supply includes a detector for generating a signal indicative of the current in the input to the switching circuitry, a band-pass filter for filtering the detected signal, an amplifier for amplifying the filtered signal, a filter for filtering the amplified signal and a comparator for converting the final signal into a stream of high and low signals that can be passed to a controller for processing as binary data stream. In a second aspect, the wireless power supply system includes a detector for generating a signal that varies in dependence on changes in the phase relationship between the current and the voltage in the primary-side tank circuit, a band-pass filter for filtering the signal, an amplifier for amplifying the filtered signal, a filter for filtering the amplified signal and a comparator for converting the final signal into a stream of high and low signals that can be passed to a controller for processing as binary data stream.

Claims

1. A wireless power supply system, comprising:

a tank circuit arranged to generate an electromagnetic field in response to a supply of input;

a power supply operatively coupled to said tank circuit, said power supply supplying an input power to said tank circuit;

a detector for generating a signal indicative of said input power supplied to said tank circuit; and

a controller for interpreting said generated signal to extract data communications carried on said generated signal.

2. The wireless power supply of claim 1 wherein said detector includes an amplifier operatively coupled to said input power, said amplifier including two inputs connected to said input power across a resistor, whereby said generated signal is representative of a current in said input power.

3. The wireless power supply of claim 1 further including filtering circuitry arranged between said detector and said controller, said filtering circuitry filtering said signal to improve differentiation of communication signals carried in said generated signal.

4. The wireless power supply of claim 3 wherein said filtering circuitry is further defined as band-pass filtering circuitry.

5. The wireless power supply of claim 4 wherein said band-pass filtering circuitry includes separate low-pass filtering circuitry and high-pass filtering circuitry.

6. The wireless power supply of claim 3 further including a comparator disposed between said detector and said controller, said comparator arranged to convert said generated signal into high and low signals corresponding to communications carried on said generated signal.

7. The wireless power supply of claim 6 further wherein said filtering circuitry and said comparator are embodied in a digital signal processor.

8. A method for detecting communications modulated onto a power signal in a wireless power supply having a tank circuit, comprising the steps of:

producing a signal indicative of current in an input power to a tank circuit;

filtering the produced signal with filtering circuitry;

amplifying the filtered signal with an amplifier;

converting the filtered signal into high and low signals corresponding to communications modulated onto the power signal; and

feeding the converted signal to a controller arranged to interpret high and low signals as a binary data stream.

9. The method of claim 8 wherein said filtering step is further defined as filtering the produced signal to reduce harmonics outside a frequency range of communications modulated onto the power signal.

10. The method of claim 9 wherein said converting step is performed by a comparator.

12. The wireless power supply system of claim 10 wherein said detector includes an input taken from said tank circuit across a ballast capacitor and phase conversion circuitry for converting an input signal into a signal varying with a phase of said current in said tank circuit.

13. The wireless power supply system of claim 12 wherein said phase conversion circuitry includes a buffer for creating a buffer copy of an input signal and an inverting buffer for creating an inverted buffer copy of an input signal.

14. The wireless power supply system of claim 13 wherein said phase conversion circuitry includes a multiplexer for generating an output signal that is a time-sliced combination of the buffer copy and the inverted buffer copy.

15. The wireless power supply system of claim 14 wherein said power supply includes a switching circuit;

and

wherein said multiplexer includes an input for controlling a timing of said multiplexer, said input being operatively couple to a drive signal for said switching circuit so that said output signal alternates between said buffer copy and said inverted buffer copy in substantial synchronization with a timing of said switching circuit.

16. The wireless power supply system of claim 15 wherein said detector includes averaging circuitry arranged such that said output signal is indicative of a running average of said voltage in said multiplexer.

17. The wireless power supply of claim 15 wherein said switching circuit includes a high-side switch controlled by a high-side switch drive signal, and

wherein said timing of said multiplexer is controlled by said high-side switch drive signal such that said output signal includes said buffer copy when said high-side switch drive signal is high and includes said inverted buffer copy when said high-side switch drive signal is low.

11. A wireless power supply system comprising:

a tank circuit arranged to generate an electromagnetic field in response to a supply of input;

a power supply operatively coupled to said tank circuit, said power supply supplying an input power to said tank circuit;

a detector for generating a signal indicative of a phase relationship between a current and a voltage in said tank circuit; and

a controller for interpreting said generated signal to extract data communications carried on said generated signal.

18. A method for detecting communications modulated onto a power signal in a wireless power supply having a tank circuit, comprising the steps of:

producing a signal that varies with changes in a phase of current in a tank circuit;

filtering the produced signal with filtering circuitry;

amplifying the filtered signal with an amplifier;

converting the filtered signal into high and low signals corresponding to communications modulated onto the power signal; and

feeding the converted signal to a controller arranged to interpret high and low signals as a binary data stream.

19. The method of claim 18 wherein said filtering step is further defined as filtering the produced signal with a band-pass filter to reduce harmonics outside a frequency range of communications modulated onto the power signal.

20. The method of claim 19 wherein said producing step includes the steps of:

providing a signal indicative of the current in the tank circuit;

producing a buffer copy of the signal;

producing an inverted buffer copy of the signal; and

combining the buffer copy and the inverted buffer copy into a time-sliced waveform alternating between the buffer copy and the inverted buffer copy.

21. The method of claim 20 wherein said producing step further includes the step of producing a signal representing a running average of said time-sliced waveform.

22. The method of claim 21 wherein said combining step is further defined as combining the buffer copy and the inverted buffer copy into a time-sliced waveform alternating between the buffer copy and the inverted buffer copy based on a timing of a switching circuit controlling a supply of power to the tank circuit.

23. The method of claim 21 wherein said combining step is further defined as combining the buffer copy and the inverted buffer copy into a time-sliced waveform alternating between the buffer copy and the inverted buffer copy based on a high-side switch drive signal for a switching circuit having a high-side switch and a low-side switch.

24. The method of claim 19 wherein said producing step includes the steps of:

providing a signal indicative of the current in the tank circuit;

producing a buffer copy of the signal using a buffer amplifier;

producing an inverted buffer copy of the signal using an inverting buffer amplifier;

combining the buffer copy and the inverted buffer copy into a time-sliced waveform alternating between the buffer copy and the inverted buffer copy; and

producing a signal representing an average of said time-sliced waveform using a 2-pole filter.