Power Links and Methods for Improved Efficiency

• US 20170201131A1
• Filed: 06/25/2015
• Published: 07/13/2017
• Est. Priority Date: 06/25/2014
• Status: Active Grant

• Current Assignee: Daxsonics Ultrasound Inc.
• Original Assignee: Dalhousie University
• Inventors: BANCE, Manohar, VIHVELIN, Hugo, LEADBETTER, Jeff, ADAMSON, Robert B.A., BROWN, Jeremy A.
• Granted Patent: US 10,559,981 B2
• Time in Patent Office: Days
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/15 using ultrasonic waves
• 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: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

Among other things, in general, methods of increasing transfer efficiency in a power link are described, as well as power links implementing such methods. Methods of dynamic charging are also described. Applications of such methods and power links include the charging of portable electronic devices as well as implantable medical devices.

Claims

1. A method of improving transfer efficiency in a power link having a send transducer and a receive transducer and configured to transmit at a transmit frequency, the method comprising detecting changes in inter-transducer separation and adjusting the transmit frequency.

7. A power link having circuitry and/or software that implements the method of any of claims 1-6.

2. A method of improving transfer efficiency in a power link having a send transducer and configured to transmit at a transmit frequency, the method comprising detecting changes in impedance phase as seen by the send transducer and adjusting the transmit frequency.

3. The method of claim 2, in which the frequency is set to the extremum closest in value to f_opt for the send transducer.

4. A method of dynamic charging in a power link, the method comprising detecting a change in an electrical impedance during charging and discontinuing the charge upon detection of the change.

5. A method of dynamic charging in a power link having a transmit unit and a receive transducer, the method comprising changing an electrical load impedance as seen by the receive transducer, wherein the transmit unit detects that more power is needed.

6. A method of maintaining high power transfer efficiency in a power link having a send transducer and configured to transmit at a transmit frequency, the method comprising the steps of:

periodically scanning the transmit frequency through a range of discrete frequencies;

digitizing current and voltage waveforms from the power link at each discrete frequency;

integrating, digitizing, and calculating impedance phase at each discrete frequency; and

setting the transmit frequency to the discrete frequency having an impedance phase extremum closest to f_opt for the send transducer.

8. The power link of claim 7 in which the link has a receive side comprising a receive transducer;

and a transmit side comprising a microcontroller having memory and a frequency tunable amplifier driving a send transducer, an impedance phase measurement circuit, and an analog to digital converter;

wherein f_opt is preselected for the send and receive transducers and is stored in the microcontroller memory;

wherein the microcontroller memory also has instructions for implementing the method of claim 6.