DETECTING DEVICE, POWER RECEIVING DEVICE, CONTACTLESS POWER TRANSMISSION SYSTEM, AND DETECTING METHOD

• US 20160218566A1
• Filed: 03/31/2016
• Published: 07/28/2016
• Est. Priority Date: 11/30/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Bunsen, Keigo, Nakano, Hiroaki, Murakami, Tomomichi, Fukuda, Shinichi
• Granted Patent: US 9,935,504 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 27/04 in circuits having distributed constants , e.g. having very long conductors or involving high frequencies
• CPC Class Codes: G01V 3/02 operating with propagation of electric current
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• 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

Abstract

Disclosed herein is a detecting device including a coil electromagnetically coupled to the external, a resonant circuit that includes at least the coil, and a detecting section that superimposes a measurement signal for measuring the Q-factor of the resonant circuit on a power transmission signal transmitted to the coil in a contactless manner and removes the power transmission signal from an alternating-current signal obtained by superimposing the measurement signal on the power transmission signal. The detecting section measures the Q-factor by using the alternating-current signal from which the power transmission signal is removed.

Claims

1. A detection circuit, comprising:

resonance circuitry configured to receive an alternating-current signal and including a coil configured to electromagnetically couple to an external device; and

detection circuitry configured to extract a measurement signal from the alternating-current signal, for measuring a Q-value of the resonance circuit.

2. The detection circuit according to claim 1, wherein a frequency of the alternating-current signal is different from a frequency of a power transfer using the resonance circuitry.

3. The detection circuit according to claim 2, wherein the frequency of the alternating-current signal is smaller than the frequency of the power transfer.

4. The detection circuit according to claim 1, wherein the detection circuitry is configured to calculate the Q-value based on a ratio between a first voltage at a first node of the resonance circuitry and a second voltage at a second node of the resonance circuitry.

5. The detection circuit according to claim 1, wherein the detection circuitry includes determination circuitry configured to compare the Q-value with a threshold value to determine whether a foreign object is in a space affecting the electromagnetic coupling.

6. The detection circuit according to claim 1, wherein the threshold value is a reference Q-value.

7. The detection circuit according to claim 1, wherein the detection circuitry includes an amplifier configured to amplify a signal received from the resonance circuitry.

8. The detection circuit according to claim 7, wherein the detection circuitry includes a filter configured to select a frequency range of an amplified signal received from the amplifier.

9. The detection circuit according to claim 8, wherein the detection circuitry includes a rectifier configured to rectify a filtered signal received from the filter.

10. The detection circuit according to claim 9, wherein the detection circuitry includes an analog-to-digital converter configured to convert an analog rectified signal received from the rectifier into a digital signal.

11. The detection circuit according to claim 10, wherein the detection circuitry includes an arithmetic processor configured to calculate the Q-value based on the digital signal.

12. The detection circuit according to claim 1, wherein the detection circuitry includes:

a first amplifier configured to amplify a first signal received from a first node of the resonance circuitry;

a second amplifier configured to amplify a second signal received from a second node of the resonance circuitry;

a first filter configured to select a first frequency range of a first amplified signal received from the first amplifier;

a second filter configured to select a second frequency range of a second amplified signal received from the second amplifier;

a first rectifier configured to rectify a first filtered signal received from the first filter;

a second rectifier configured to rectify a second filtered signal received from the second filter;

an analog-to-digital converter configured to convert a first analog rectified signal received from the first rectifier into a first digital signal; and

to convert a second analog rectified signal received from the second rectifier into a second digital signal; and

an arithmetic processor configured to calculate the Q-value based on a ratio between the second digital signal and the first digital signal.

13. The detecting device according to claim 1, wherein the detecting device is a part of a power transmission system including a power transmitting device.

14. The detecting device according to claim 1, wherein the measurement signal is generated by a first signal source, the alternating-current signal is generated by a second signal source, and the first signal source is different from the second signal source.

15. A detecting method, comprising:

receiving an alternating-current signal by resonance circuitry including a coil configured to electromagnetically couple to an external device, and

extracting a measurement signal from the alternating-current signal, for measuring a Q-value of the resonance circuitry.

16. The detecting method according to claim 15, wherein a frequency of the alternating-current signal is different from a frequency of a power transfer using the resonance circuitry.

17. The detection circuit according to claim 16, wherein the frequency of the alternating-current signal is smaller than the frequency of the power transfer.

18. The detecting method according to claim 15, further comprising calculating the Q-value based on a ratio between a first voltage at a first node of the resonance circuitry and a second voltage at a second node of the resonance circuitry.

19. The detecting method according to claim 15, further comprising comparing the Q-value with a threshold value to determine whether a foreign object is in a space affecting the electromagnetic coupling.

20. The detecting method according to claim 19, wherein the threshold value is a reference Q-value.

21. The detecting method according to claim 15, further comprising amplifying a signal received from the resonance circuitry.

22. The detecting method according to claim 21, further comprising selecting a frequency range of the amplified signal.

23. The detecting method according to claim 22, further comprising rectifying the filtered signal.

24. The detecting method according to claim 23, further comprising converting the rectified signal into a digital signal.

25. The detecting method according to claim 24, further comprising calculating the Q-value based on the digital signal.

26. The detecting method according to claim 15, further comprising:

amplifying a first signal received from a first node of the resonance circuitry;

amplifying a second signal received from a second node of the resonance circuitry;

selecting a first frequency range of the first amplified signal;

selecting a second frequency range of the second amplified signal;

rectifying a first filtered signal received from the first filter;

rectifying a second filtered signal received from the second filter;

converting a first rectified signal into a first digital signal;

converting a second rectified signal into a second digital signal; and

calculating the Q-value based on a ratio between the second digital signal and the first digital signal.

27. A power transmission detecting device, comprising:

resonance circuitry configured to receive an input signal and including a coil configured to electromagnetically couple to an external device; and

detection circuitry configured to use a measurement signal to measure a Q-value of the resonance circuitry,

wherein the input signal has a first frequency and the measurement signal has a second frequency.

28. The power transmission detecting device according to claim 27, wherein the first frequency is different from the second frequency.

29. The power transmission detecting device according to claim 28, wherein the first frequency is higher than the second frequency.

30. The power transmission detecting device according to claim 29, wherein the measurement signal is generated by a first signal source, the input signal is generated by a second signal source, and the first signal source is different from the second signal source.