Inductive power harvester with power limiting capability

Patent metadata

Field	Value
Publication number	US-2016276954-A1
Application number	US-201514661468-A
Country	US
Kind code	A1
Filing date	Mar 18, 2015
Priority date	Mar 18, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

A power harvester having a current transformer configured to be inductively coupled to a current conductor and a circuit for delivering power to a load. The transformer core has two sections joined together and separable from one another at interleaved portions, allowing the transformer to be installed around the current conductor. The circuit includes a rectifier coupled to the transformer and a transistor coupled in series between the rectifier and a load. The transistor receives an output current from the rectifier and provides power to the load. A resistor is coupled to the transistor and the load, and the transistor and resistor provide for limiting of the power to the load over a wide range of the conductor line currents.

First claim

1 . A power harvester, comprising:
a transformer having a core and a coil around the core, wherein the core has an interleaved portion and the transformer is configured to be inductively coupled to a current conductor; a rectifier coupled to the coil; a transistor coupled in series between the rectifier and a load, wherein the transistor receives an output current from the rectifier and provides power to the load; and a resistor coupled to the transistor and the load, wherein the transistor and resistor provide for limiting of the power to the load over a particular range of currents within the current conductor.

2 . The power harvester of claim 1 , wherein the rectifier comprises a diode bridge.

3 . The power harvester of claim 1 , wherein the transistor comprises a depletion transistor.

4 . The power harvester of claim 1 , wherein the resistor is coupled in series between the transistor and the load.

5 . The power harvester of claim 1 , wherein the load contains a parallel capacitor.

6 . The power harvester of claim 1 , wherein the load contains a parallel zener diode.

7 . The power harvester of claim 1 , wherein the resistor is coupled in parallel with the load.

8 . The power harvester of claim 1 , wherein the core comprises a first section and a second section, and the first section is separable from the second section at the interleaved portion.

9 . The power harvester of claim 1 , wherein core comprises laminated steel sheets.

10 . The power harvester of claim 1 , wherein the coil is around the interleaved portion.

11 . The power harvester of claim 1 , wherein the interleaved portion is comprised of rectangular shaped protrusions.

12 . A power harvester, comprising:
a transformer configured to be inductively coupled to a current conductor and having a core and a coil around the core, wherein the core has first and second sections, first and second interleaved portions, and the first section is separable from the second section at the first and second interleaved portions; a rectifier coupled to the coil; a transistor coupled in series between the rectifier and a load, wherein the transistor receives an output current from the rectifier and provides power to the load; and a resistor coupled to the transistor and the load, wherein the transistor and resistor provide for limiting of the power to the load over a particular range of currents within the current conductor.

13 . The power harvester of claim 12 , wherein the rectifier comprises a diode bridge.

14 . The power harvester of claim 12 , wherein the transistor comprises a depletion transistor.

15 . The power harvester of claim 12 , wherein the resistor is coupled in series between the transistor and the load.

16 . The power harvester of claim 12 , wherein the resistor is coupled in parallel with the load.

17 . The power harvester of claim 12 , wherein the load contains a parallel capacitor.

18 . The power harvester of claim 12 , wherein the load contains a parallel zener diode.

19 . The power harvester of claim 12 , wherein core comprises laminated steel sheets.

20 . The power harvester of claim 12 , wherein the coil comprises a first coil of insulated wire around a first part of the core and a second coil of insulated wire around a second part of the core opposite the first part, and the first coil is coupled in series with the second coil.

21 . The power harvester of claim 20 , wherein the first coil is around the first interleaved portion, and the second coil is around the second interleaved portion.

22 . The power harvester of claim 12 , wherein the first and second sections are each comprised of U-shaped portions and I-shaped portions.

23 . The power harvester of claim 12 , wherein the first and second interleaved portions are each comprised of rectangular shaped protrusions.

Assignees

• 3M Innovative Properties Co

Inventors

• Vos Martin J

Classifications

• H01F38/14

  Inductive couplings {(for wireless supply or distribution of electric power using inductive coupling H02J50/10)} · CPC title

• H02M3/155

  using semiconductor devices only · CPC title

• H02M7/2176

  comprising a passive stage to generate a rectified sinusoidal voltage and a controlled switching element in series between such stage and the output · CPC title

• H01F27/245 Primary

  made from sheets, e.g. grain-oriented (H01F27/26 takes precedence) · CPC title

• H01F38/30

  Constructions · CPC title