Communication through a barrier

• US 20090156119A1
• Filed: 12/16/2008
• Published: 06/18/2009
• Est. Priority Date: 12/14/2007
• Status: Active Grant

• Current Assignee: Wfs Technologies Ltd.
• Original Assignee: Wfs Technologies Ltd.
• Inventors: Hyland, Brendan, Rhodes, Mark
• Granted Patent: US 8,175,526 B2
• Time in Patent Office: Days
• US Class Current: 455/41.100
• CPC Class Codes: H01F 2038/143 for signals
• CPC Class Codes: H01F 3/00 Cores, Yokes, or armatures magnetic materials H01F1/00; permanent magnets H01F7/02
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H04B 5/00 Near-field transmission systems, e.g. inductive or capacitive transmission systems
• CPC Class Codes: H04B 5/0031 for data transfer
• CPC Class Codes: H04B 5/0037 for power transfer
• CPC Class Codes: H04B 5/0093 with one coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A magnetic flux coupling transducer system comprising a primary coil (51) and primary coupling core (52) and a secondary coil (54) and secondary coupling core (55) for passing communications signals and/or electrical power from one side of an electrically conductive barrier to receiving equipment on the other side.

Claims

1. A magnetic flux coupling transducer system comprising a primary coil and primary coupling core and a secondary coil and secondary coupling core for passing communications signals and/or electrical power from one side of an electrically conductive barrier to receiving equipment on the other side.

2. A magnetic flux coupling transducer system as claimed in claim 1 wherein the communications signal comprises a carrier signal that is modulated to represent data.

3. A magnetic flux coupling transducer system as claimed in claim 2 wherein the signal received in the secondary coil is de-modulated to recover transmitted data.

4. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the secondary core magnetic permeability is greater than that of the barrier material at the frequency of operation, for example two or more times greater than that of the barrier material at the frequency of operation.

5. A magnetic flux coupling transducer system as claimed in any of the preceding claims, wherein the coupling core material has a bulk electrical conductivity of less than 10 mS/m.

6. A magnetic flux coupling transducer system as claimed in any of the preceding claims, wherein the primary coupling core defines part of a coupling arm that has a length that is greater than the barrier thickness and/or the secondary coupling core defines part of a coupling arm that has a length that is greater than the barrier thickness

7. A magnetic flux coupling transducer system as claimed in any of the preceding claims comprising means for implementing unidirectional communications and/or electrical power transfer.

8. A magnetic flux coupling transducer system as claimed in any of claims 1 to 6 comprising means for implementing a bidirectional communications and/or electrical power transfer.

9. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the coupling core has contact surfaces that are polished to reduce surface roughness.

10. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the barrier surface is polished to reduce surface roughness.

11. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the coupling core is bonded in contact with the barrier.

12. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein a flexible material with relative magnetic permeability greater than 10 is placed between the first and/or second coupling core surfaces and the barrier.

13. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein a flexible polymer loaded with ferrite powder to achieve a bulk relative magnetic permeability greater than 10 is placed between the first and/or second coupling core surfaces and the barrier.

14. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein a powder material with relative magnetic permeability greater than 10 is enclosed by a flexible membrane and placed between the first and/or second coupling core surfaces and the barrier.

15. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the first and/or second coupling core is bonded using adhesive loaded with powder magnetic permeability to achieve a bulk relative magnetic permeability of greater than 10.

16. A magnetic flux coupling transducer system as claimed in any of the preceding claims comprising means for applying a direct current component to the primary and/or secondary coil to clamp the primary and/or secondary coupling core to the barrier.

17. A magnetic flux coupling transducer system as claimed in claim 2 or any claim dependent on claim 2, wherein the carrier frequency is greater than 10 kHz.

18. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the coupling poles are separated in the X-Y plane by a distance greater than or equal to the barrier thickness.

19. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein a signal carrying waveform and a power carrying waveform are transmitted simultaneously and one or more frequency dependent filters are provided to prevent the power carrying waveform from impinging on receiver circuitry for the signal carrying waveform.

20. A magnetic flux coupling transducer system as claimed in any of the preceding claims comprising transmit circuitry that includes a modulator and receive circuitry that includes a demodulator.

21. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the barrier has a magnetic relative permeability of greater than 10.

22. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the magnetic reluctance of the secondary coupling core is less than 100 times greater than the magnetic reluctance of the leakage path between the primary coupling arm contact points running through the barrier material.

23. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the relative magnetic permeability of the primary coupling core is greater than 100.

24. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the primary coil and secondary coil have a turns ratio designed to meet a desired transformer ratio.

25. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the frequency of operation is selected to enhance the ratio of magnetic reluctance of the through barrier leakage path divided by the magnetic reluctance of the secondary coupling core

26. A magnetic flux coupling transducer system as claimed in any of the preceding claims wherein the first and/or second coupling core material has an electrical conductivity of less than 10 mS/M.

27. A magnetic flux coupling transducer as claimed in any of the preceding claims wherein the primary coupling core and secondary coupling core are U-shaped, each core having substantially co-planar coupling faces.

28. A magnetic flux coupling transducer as claimed in any of the preceding claims wherein the primary coupling core and secondary core are rotationally symmetric and co-axial, each core having substantially co-planar coupling faces.

29. An installation method for a magnetic flux coupling transducer system as claimed in any of the preceding claims wherein alignment of the secondary coupling core and coil relative to the primary coupling core and coil is based on signal strength.

30. An installation method for a magnetic flux coupling transducer system as claimed in claim 29 wherein alignment of a secondary U-shaped transducer relative to a primary U-shaped transducer is based on signal strength mapped against X-Y position and relative rotation.

31. A kit of parts for forming a magnetic flux coupling transducer as claimed in any of claims 1 to 28.

32. A structure or vehicle or barrier fitted with a magnetic flux coupling transducer as claimed in any of claims 1 to 28.