Transducer circuit coupled to a control unit through a cable

• US 7,583,562 B2
• Filed: 11/14/2006
• Issued: 09/01/2009
• Est. Priority Date: 11/14/2005
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens Milltronics Process Instruments, Inc. (Siemens AG)
• Inventors: Lyon, George Quinton
• Primary Examiner(s): PIHULIC, DANIEL T
• Application Number:
  US11/598,882
• Publication Number:
  US 20070194659A1
• Time in Patent Office: 1,022 Days
• Field of Search: 367/903, 367/135
• US Class Current: 367/135
• CPC Class Codes: G01F 23/284 Electromagnetic waves
• CPC Class Codes: G01F 23/2962 Measuring transit time of reflected waves
• CPC Class Codes: Y10S 367/903 Transmit-receive circuitry

Abstract

The transducer circuit includes a transducer component, a drive circuit for the transducer component, a control port for coupling the drive circuit to a control unit and a modulator. The modulator has an input port for receiving a signal or data from another device. The modulator has an output which is coupled to an output stage in the drive circuit. The modulator operates to transmit data, received at the input port, through the drive circuit and the control port to a control unit.

Claims

1. A transducer circuit coupled to a control unit via a cable, comprising:

a transducer component;

a control port for connecting to the cable;

a data port;

a modulator having an input port and an output port, said input port being coupled to said data port for receiving a data signal; and

a drive circuit coupled to said transducer component, the drive circuit comprising;

an input-output stage coupled to said control port, and

an output stage coupled to the output port of said modulator for outputting a modulated signal to the control unit corresponding to said received data signal,

wherein said modulator comprises a pulse amplitude modulator and converts said data signal into a pulse amplitude modulated signal for the control unit.

2. The transducer circuit according to claim 1, further comprising a power supply circuit for said modulator, said power supply circuit comprising an energy storage device coupled to said drive circuit for tapping energy.

3. The transducer circuit according to claim 1, wherein said energy storage device comprises a capacitor and a blocking diode.

4. The transducer circuit according to claim 1, wherein said drive circuit comprises a transformer comprising:

an electromagnetically coupled primary winding comprising said input-output stage and being connected to said control port,

an electromagnetically coupled secondary winding connected to said transducer component, and

an electromagnetically coupled auxiliary winding comprising said output stage for said drive circuit.

5. The transducer circuit according to claim 1, wherein said modulator comprises a pulse width modulator and converts said data signal into a pulse width modulated data signal for the control unit.

6. The transducer circuit according to claim 5, wherein said modulated data signal is transmitted as an alternating current signal burst.

7. The transducer circuit according to claim 6, wherein said modulated data signal is transmitted as a plurality of alternating current signal bursts.

8. The transducer circuit according to claim 1, wherein said modulator comprises a pulse position modulator and converts said data signal into a pulse position modulated signal for the control unit.

9. A transducer circuit coupled to a control unit via a cable, comprising:

a transducer component;

a control port for connecting to the cable;

a data port;

a modulator having an input port and an output port, said input port being coupled to said data port for receiving a data signal; and

a drive circuit coupled to said transducer component, the drive circuit comprising;

an input-output stage coupled to said control port, and

an output stage coupled to the output port of said modulator for outputting a modulated signal to the control unit corresponding to said received data signal,

wherein said modulator applies binary phase shift keying to the received data signal.

10. The transducer circuit according to claim 9, wherein the control unit includes a decoder for decoding said modulated data signal.

11. The transducer circuit according to claim 9, further comprising a power supply circuit for said modulator, said power supply circuit comprising an energy storage device coupled to said drive circuit for tapping energy.

12. The transducer circuit according to claim 9, wherein said energy storage device comprises a capacitor and a blocking diode.

13. The transducer circuit according to claim 9, wherein said drive circuit comprises a transformer comprising:

an electromagnetically coupled primary winding comprising said input-output stage and being connected to said control port,

an electromagnetically coupled secondary winding connected to said transducer component, and

an electromagnetically coupled auxiliary winding comprising said output stage for said drive circuit.

14. The transducer circuit according to claim 9, wherein said modulator comprises a pulse width modulator and converts said data signal into a pulse width modulated data signal for the control unit.

15. The transducer circuit according to claim 14, wherein said modulated data signal is transmitted as an alternating current signal burst.

16. The transducer circuit according to claim 15, wherein said modulated data signal is transmitted as a plurality of alternating current signal bursts.

17. The transducer circuit according to claim 9, wherein said modulator comprises a pulse position modulator and converts said data signal into a pulse position modulated signal for the control unit.

18. The transducer circuit according to claim 9, wherein the control unit includes a decoder for decoding said modulated data signal.

19. A transducer circuit coupled to a control unit via a cable, comprising:

a transducer component;

a control port for connecting to the cable;

a data port;

a modulator having an input port and an output port, said input port being coupled to said data port for receiving a data signal; and

a drive circuit coupled to said transducer component, the drive circuit comprising;

an input-output stage coupled to said control port, and

an output stage coupled to the output port of said modulator for outputting a modulated signal to the control unit corresponding to said received data signal,

wherein said modulator includes frequency division multiplexing to avoid interference between said modulated data signal and a transducer signal.

20. The transducer circuit according to claim 19, further comprising a power supply circuit for said modulator, said power supply circuit comprising an energy storage device coupled to said drive circuit for tapping energy.

21. The transducer circuit according to claim 19, wherein said energy storage device comprises a capacitor and a blocking diode.

22. The transducer circuit according to claim 19, wherein said drive circuit comprises a transformer comprising:

an electromagnetically coupled primary winding comprising said input-output stage and being connected to said control port,

an electromagnetically coupled secondary winding connected to said transducer component, and

an electromagnetically coupled auxiliary winding comprising said output stage for said drive circuit.

23. The transducer circuit according to claim 19, wherein said modulator comprises a pulse width modulator and converts said data signal into a pulse width modulated data signal for the control unit.

24. The transducer circuit according to claim 23, wherein said modulated data signal is transmitted as an alternating current signal burst.

25. The transducer circuit according to claim 24, wherein said modulated data signal is transmitted as a plurality of alternating current signal bursts.

26. The transducer circuit according to claim 19, wherein said modulator comprises a pulse position modulator and converts said data signal into a pulse position modulated signal for the control unit.

27. The transducer circuit according to claim 19, wherein the control unit includes a decoder for decoding said modulated data signal.