# US 2017/0256992 A1 · Methods and devices for controlling wireless power transfer levels

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- Number: US 2017/0256992 A1
- Document ID: US20170256992A1
- Status: Published application
- Kind: A1
- Application number: 15/496,863
- Filed: 2017-04-25
- Published: 2017-09-07
- Earliest claimed: 2014-12-23
- Assignees: UVic Industry Partnerships Inc.
- Applicants: UVic Industry Partnerships Inc.
- Inventors: Basem M. Badr; Arthur Makosinski; Kerry R. Delaney; Nikolai Dechev
- Web page: https://patentgrep.com/patent/US20170256992A1

## CPC

- H02J 50/12: of the resonant type
- H01F 27/28: Coils; Windings; Conductive connections
- H02J 50/60: responsive to the presence of foreign objects, e.g. detection of living beings
- H02J 50/70: involving the reduction of electric, magnetic or electromagnetic leakage fields
- H02M 3/33523: {with galvanic isolation between input and output of both the power stage and the feedback loop}
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)

## 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

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

### Claim 2 (depends on 1)

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.

### Claim 3 (depends on 1)

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

### Claim 4 (depends on 1)

The device of claim 1, wherein the rectifier is electrically coupled to a stimulator component and/or a microprocessor.

### Claim 5 (depends on 1)

The device of claim 1, further comprising a transistor electrically coupled to the switching capacitor and the microcontroller, wherein the microcontroller is coupled to the switching capacitor so as to tune or detune the resonant frequency.

### Claim 6 (depends on 5)

The device of claim 5, wherein the switching capacitor is connected to the transistor such that the switching capacitor is connected to a drain of the transistor and a transistor source is connected to ground.

### Claim 7 (depends on 1)

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

### Claim 8 (depends on 1)

The device of claim 1, wherein the switching capacitor is coupled in parallel with the tank capacitor.

### Claim 9 (depends on 1)

The device of claim 1, wherein the switching capacitor is coupled in series with the tank capacitor.

### Claim 10 (depends on 1)

The device of claim 1, wherein the microcontroller includes an analog input configured to adjust a capacitance associated with the switching capacitor.

### Claim 11 (depends on 1)

The device of claim 1, further comprising two switching capacitors that are electrically coupled to the microcontroller and the tank capacitor and that can be switched on or off by the microcontroller.

### Claim 12 (depends on 1)

The device of claim 1, further comprising four switching capacitors, 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.

### Claim 13

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 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) a switching capacitor electrically coupled to the tank capacitor; and (vi) a microcontroller electrically coupled to the switching capacitor 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.

### Claim 14 (depends on 13)

The system of claim 13, wherein the primary circuit further comprises a power supply, a signal generator, a gate driver, an amplifier, or a combination thereof.

### Claim 15

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
adjusting a resonant frequency difference between the secondary circuit and the primary circuit based on the measured voltage.

### Claim 16 (depends on 15)

The method of claim 15, wherein the resonant frequency difference is adjusted by tuning a resonant frequency of the secondary circuit.

### Claim 17 (depends on 15)

The method of claim 15, wherein the secondary circuit comprises a switching capacitor that is switched to detune the resonant frequency.

### Claim 18 (depends on 15)

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

### Claim 19 (depends on 17)

The method of claim 17, wherein the resonant frequency difference is adjusted by adjusting the switching capacitor of the secondary circuit.

### Claim 20 (depends on 17)

The method of claim 17, wherein the resonant frequency difference is adjusted by applying a control voltage to a transistor coupled to the switching capacitor.

### Claim 21 (depends on 17)

The method of claim 17, further comprising electrically coupling a microcontroller so as to adjust the switching capacitor of the secondary circuit so as to adjust the resonant frequency difference.

### Claim 22 (depends on 19)

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

### Claim 23 (depends on 19)

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