Methods and devices for controlling wireless power transfer levels

• US 10,424,968 B2
• Filed: 04/25/2017
• Issued: 09/24/2019
• Est. Priority Date: 12/23/2014
• Status: Active Grant

• Current Assignee: UVic Industry Partnerships Inc. (University of Victoria)
• Original Assignee: UVic Industry Partnerships Inc. (University of Victoria)
• Inventors: Badr, Basem M., Makosinski, Arthur, Delaney, Kerry R., Dechev, Nikolai
• Primary Examiner(s): Borroto, Alfonso Perez
• Assistant Examiner(s): Yeshaw, Esayas G
• Application Number:
  US15/496,863
• Publication Number:
  US 20170256992A1
• Time in Patent Office: 882 Days
• CPC Class Codes: H01F 27/28 Coils; Windings; Conductive connections
• 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 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop

Abstract

Disclosed herein are embodiments of novel WPT systems, devices, and methods of using the same. Also disclosed herein are methods for controlling the power delivered from a stationary source (e.g., a primary coil) to a moving telemetric device (e.g., a secondary coil) via magnetic resonance coupling. The systems, device, and methods described herein can be used to tune and/or detune resonant frequency between a primary coil and a telemetric device so as to prevent device malfunction and/or tissue damage for the small animals associated with the telemetric device.

Claims

1. A device, comprising:

a coil defining a coil axis;

a tank capacitor electrically coupled to the coil and wherein the coil and the tank capacitor define a resonant frequency;

a rectifier coupled to the coil so as to receive and rectify an electrical voltage induced in the coil;

four switching capacitors electrically coupled to the tank capacitor, wherein two switching capacitors are configured to tune the device when heat increases due to high induced current, one switching capacitor is configured to tune the device, and one switching capacitor is configured to compensate any decreasing secondary capacitance of the tank capacitor; and

a microcontroller electrically coupled to the four switching capacitors so as to tune or detune the resonant frequency established by the coil, the tank capacitor, and the four switching capacitors.

2. The device of claim 1, further comprising a ferrite rod having a rod axis and situated to be at least partially proximate to the coil.

3. The device of claim 1, wherein the rectifier is a half-wave bridge rectifier.

4. The device of claim 1, wherein the rectifier is electrically coupled to a stimulator component.

5. The device of claim 1, further comprising a transistor electrically coupled to at least one of the four switching capacitors and the microcontroller, wherein the microcontroller is coupled to at least one of the four switching capacitors so as to tune or detune the resonant frequency.

6. The device of claim 5, wherein at least one of the four switching capacitors is connected to the transistor such that at least one of the four switching capacitors is connected to a drain of the transistor and a transistor source is connected to ground.

7. The device of claim 1, wherein the microcontroller is configured to control at least one of the four switching capacitors by switching the one or more transistors on or off.

8. The device of claim 1, wherein at least one of the four switching capacitors is coupled in parallel with the tank capacitor.

9. The device of claim 1, wherein at least one of the four switching capacitors is coupled in series with the tank capacitor.

10. The device of claim 1, wherein the microcontroller includes an analog input configured to adjust a capacitance associated with at least one of the four switching capacitors.

11. A system, comprising:

a primary circuit comprising (i) a primary coil defining a primary coil axis; and

(ii) a primary tank capacitor coupled to the primary coil; and

a secondary circuit comprising (i) a secondary coil defining a secondary coil axis;

(ii) a secondary tank capacitor;

wherein the secondary coil and the secondary tank capacitor define a resonant frequency;

(iv) a rectifier coupled to the secondary coil so as to receive and rectify an electrical voltage induced in the secondary coil by the primary coil;

(v) four switching capacitors electrically coupled to the tank capacitor, wherein two switching capacitors are configured for tuning in response to high induced current, one switching capacitor is configured to tune the with respect to the primary circuit, and one switching capacitor is configured to compensate any decreasing secondary capacitance of the secondary tank capacitor; and

(vi) a microcontroller electrically coupled to the four switching capacitors so as to tune or detune a secondary resonant frequency of the secondary circuit with respect to a primary resonant frequency associated with the primary coil and the primary tank capacitor.

12. The system of claim 11, wherein the primary circuit further comprises a power supply, a signal generator, a gate driver, an amplifier, or a combination thereof.

13. A method, comprising:

inducing an oscillating voltage in a secondary circuit with an oscillating electromagnetic field in a primary circuit, wherein the secondary circuit is part of a telemetric device associated with an animal and the primary circuit is part of a cage in which the animal is physically confined;

measuring a voltage associated with the oscillating voltage in the secondary circuit with a microcontroller using an analog input; and

providing four switching capacitors in the secondary circuit, wherein two switching capacitors are configured for tuning in response to high induced current, one switching capacitor is configured to tune the with respect to the primary circuit, and one switching capacitor is configured to compensate any decreasing secondary capacitance of a secondary tank capacitor; and

adjusting a resonant frequency difference between the secondary circuit and the primary circuit based on the measured voltage with one or more of the four switching capacitors.

14. The method of claim 13, wherein the resonant frequency difference is adjusted by tuning a resonant frequency of the secondary circuit.

15. The method of claim 13, wherein the measured voltage is a rectified voltage associated with an alternating voltage in the secondary circuit.

16. The method of claim 13, wherein the resonant frequency difference is adjusted by adjusting at least one of the four switching capacitors of the secondary circuit.

17. The method of claim 13, wherein the resonant frequency difference is adjusted by applying a control voltage to a transistor coupled to at least one of the four switching capacitors.

18. The method of claim 13, further comprising electrically coupling a microcontroller so as to adjust at least one of the four switching capacitors of the secondary circuit so as to adjust the resonant frequency difference.

19. The method of claim 13, wherein the resonant frequency difference is adjusted so as to decrease the measured rectified voltage.

20. The method of claim 13, wherein the resonant frequency difference is adjusted so as to increase the measured rectified voltage.