Transducer and interrogator device

• US 5,701,121 A
• Filed: 12/12/1994
• Issued: 12/23/1997
• Est. Priority Date: 04/11/1988
• Status: Expired due to Term

• Current Assignee: SATO Vicinity Pty Limited (SATO Holdings Corporation)
• Original Assignee: Magellan Technology Pty. Ltd (SATO Holdings Corporation), Uniscan Limited
• Inventors: Murdoch, Graham Alexander M.
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): HILL, ANDREW M
• Application Number:
  US08/356,782
• Time in Patent Office: 1,107 Days
• Field of Search: 340/825.54, 340/825.72, 340/572, 340/870.3, 340/870.31, 340/870.32, 340/825.3, 340/825.31, 340/825.69, 455/41, 455/60, 342/44, 342/51, 324/207.15, 324/207.16, 324/207.22
• US Class Current: 340/10.34
• CPC Class Codes: B61L 23/005 Automatic control or safety means for points for operator-less railway, e.g. transportation systems
• CPC Class Codes: B61L 25/043 using inductive tags
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• 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: H03J 2200/10 Tuning of a resonator by means of digitally controlled capacitor bank
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A transducer and interrogator device is disclosed in which the interrogator provides power and information to the transducer via a magnetic field. The transducer is a passive actuator device that includes an inductive pickup coil that, when subjected to the interrogator'"'"'s magnetic field, powers the passive actuator and an external electrical device. The magnetic field produced by the interrogator can be modulated in such a manner as to provide identification, commands, or other information to the passive actuator without substantially reducing the power transferred to the passive actuator. Modulation can be by amplitude, phase, frequency, pulse width, or pulse position. An antiphase magnetic field can also be generated to cancel far field radiation. The passive actuator can include a logic circuit to demodulate any received data from the interrogator via the magnetic field, which data can be used to control the operation of the external device. The passive actuator can also include a circuit for transmitting information back to the interrogator using the power extracted from the interrogator'"'"'s magnetic field. Transmission can be either by a modulated electromagnetic signal generated by an oscillator internal to the passive actuator or by coupled impedance signalling using the passive actuator'"'"'s pickup coil.

Claims

1. A passive actuator device for supplying power to an external device in response to an impinging magnetic powering field, comprising:

an inductive coil adapted to receive a magnetic powering field transmitted from an interrogator, said coil providing an induced powering signal when in the presence of the magnetic field,

a first portion of said powering signal supplying power to said actuator device,

a plurality of output terminals for connection to the external device, and

a circuit operable upon being energized by the first portion of the powering signal to provide selectively a further portion of said powering signal as supply power to at least one of said output terminals to thereby supply power to the external device.

2. An actuator device as claimed in claim 1, wherein said inductive coil is adapted to receive data via a modulated magnetic field and wherein the actuator device further comprises:

a circuit coupled to said inductive coil and adapted to extract the data received by said inductive coil,

wherein said data includes command and/or informational signals.

3. An actuator device as claimed in claim 2, wherein said circuit includes a switch coupled to said inductive coil;

and

wherein said circuit is operable to determine if the data constitutes a valid command and, upon receipt of the valid command, activate said switch to provide the further portion of the powering signal to the external device.

4. An actuator device as claimed in claim 2, wherein said inductive coil and said circuit are adapted to obtain the powering signal and the data from a single modulated magnetic field.

5. An actuator device as claimed in claim 2, wherein said switch comprises a transistor.

6. An actuator device as claimed in claim 1, wherein the additional supply power is sourced from a tap on said coil.

7. An actuator device as claimed in claim 1, further comprising:

driver means for providing information, status and/or code signals to said coil for transmission to said interrogator.

8. An actuator device as claimed in claim 7, further comprising rectifer means coupled between one end of said coil and a reference potential, said driver means being coupled to said coil between said one end of said coil and its other end wherein said coil is adapted to transmit said information, status and/or code signals.

9. An actuator device as claimed in claim 1, including means for dissipating any unused powering signal.

10. An actuator device as claimed in claim 1, further comprising modulator means adapted to modulate said powering signal with data, status and/or information signals for transmission via said coil to said interrogator.

11. An actuator device as claimed in claim 10, wherein said modulator means utilizes coupled impedance signalling.

12. An actuator device as claimed in claim 10, wherein said modulator means utilizes shunting of a capacitor coupled to said coil, said shunting being synchronous with said powering signal.

13. A passive actuator device adapted to be influenced by a magnetic field that is transmitted from an interrogator and that is modulated in accordance with a data communication, said device comprising:

receiver means including an inductive coil adapted to receive the magnetic field and provide an induced powering signal when in the presence of the magnetic field, a first portion of said powering signal providing a source of power to said actuator device,

logic means coupled to said receiver means and adapted to demodulate the powering signal to thereby extract the data communication, said logic means being further adapted to provide a control signal in accordance with the data communication, and

switch means responsive to said control signal and being adapted to direct a further portion of said powering signal to an external electric or electromechanical device.

14. An actuator as claimed in claim 13, wherein the actuator is mounted on a rolling stock railway wagon and the external device is a solenoid.

15. An actuator as claimed in claim 14, further comprising sensing means adapted to provide information regarding door operation to said actuator.

16. An actuator as claimed in claim 13 wherein in response to said control signal, said logic means provides a command signal to provide a controlling function on said external device.

17. An actuator device as claimed in claim 13 or 16, further comprising:

transmitter means coupled to said logic means, said transmitter means being adapted to transmit second data to the interrogator.

18. An actuator device as claimed in claim 17, wherein said second data includes information received from the external device.

19. An actuator as claimed in claim 13, wherein said inductive coil is a single inductive coil.

20. An actuator as claimed in claim 19, wherein the actuator is mounted on a rolling stock railway wagon and the external device is a solenoid operated pneumatic valve operable to open doors on said wagon.

21. An actuator as claimed in claim 20, further comprising sensing means adapted to provide information regarding door operation to said actuator.

22. An actuator as claimed in claim 19, wherein the further portion of said powering signal is sourced from a tap on said inductive coil.

23. An actuator as claimed in claim 19, further including means for dissipating any unused powering signal.

24. An actuator as claimed in claim 19, wherein the powering signal has a frequency and wherein said inductive coil is tuned by shunting of a capacitor, the shunting being synchronous with the frequency of said powering signal.

25. An actuator as claimed in claim 19, wherein in response to said control signal, said logic means provides a command signal to provide a controlling function on said external device.

26. An actuator as claimed in claim 25, wherein said data includes command and/or informational signals.

27. An actuator as claimed in claim 19 or 25, further comprising transmitter means coupled to said logic means, said transmitter means being adapted to transmit data signals to the interrogator.

28. An actuator as claimed in claim 19 or 25, further comprising modulator means adapted to modulate said powering signal with data, status and/or information signals for transmission by said inductive coil to the interrogator.

29. An actuator as claimed in claim 28, wherein said modulator means utilizes coupled impedance signalling.

30. An actuator as claimed in claim 28, wherein said modulator means utilizes shunting of a capacitor coupled to said coil, said shunting being synchronous with said powering signal.

31. An actuator as claimed in claim 27 or 28, wherein said data signals include information received from the external device.

32. A system for remote actuation of an external device, comprising:

a passive actuator device and an inductive powering device adapted to remotely power said actuator device, said powering device generating a first near field, a first far field, a second near field and a second far field,

said passive actuator device comprising;

an inductive coil adapted to extract power from said near fields when in relatively close proximity to said powering device and to thereby provide a powering signal, wherein said actuator device is configured such that a first portion of the powering signal supplies electrical power used by said actuator device, and

a circuit operable upon being energized by the first portion of the powering signal to provide selectively a further portion of the powering signal as supply power to the external device, and

said powering device comprising;

a field generating means having a first portion and a second portion, the first portion being adapted to generate the first fields, the second portion being adapted to generate the second fields, wherein;

the first portion generates the first far field substantially antiphase with respect to the second far field generated from the second portion such that the first far field and the second far field substantially cancel each other at a predetermined distance from the generating means.

33. A system as claimed in claim 32, wherein each of the first and second near fields are substantially undiminished by the presence of the other of the first and second near fields.

34. A system as claimed in claim 33, wherein the first and second portions each comprise a coil.

35. A system as claimed in claim 34, wherein said first and second portions are located along opposite sides of a railway line and are spaced along the railway line by a distance approximately equal to the length of a railway wagon.

36. A system as claimed in claim 32, wherein the first and second portions each comprise a coil.

37. A system as claimed in claim 36, wherein said first and second portions are located along opposite sides of a railway line and are spaced along the railway line by a distance approximately equal to the length of a railway wagon.

38. A system as claimed in claim 32, wherein the actuator is mounted on a rolling stock railway wagon and the external device is a solenoid, further wherein

the powering device is located at a wagon unloading terminus.

39. A system as claimed in claim 32, wherein said inductive coil is a single inductive coil.