Magnetoresistive smart switch

• US 20040095218A1
• Filed: 11/14/2002
• Published: 05/20/2004
• Est. Priority Date: 11/14/2002
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Wan, Hong, Freeman, Michael L., Mallison, Edgar R.
• Granted Patent: US 6,960,974 B2
• Time in Patent Office: Days
• US Class Current: 335/207
• CPC Class Codes: G01D 3/08 with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown
• CPC Class Codes: G01D 5/14 influencing the magnitude of a current or voltage

Abstract

A smart switch has a magnetic operator, at least one magnetic sensor located to sense movement of the magnetic operator, and a processor that processes an output of the magnetic sensor so as to detect right and left over travel ranges and a normal operating range of the magnetic operator. The magnetic sensor may be a magnetoresistive sensor.

Claims

1. A smart switch comprising:

a magnetic operator;

at least one magnetic sensor located to sense movement of the magnetic operator; and

,

a processor arranged to process an output of the magnetic sensor so as to detect an over travel range and a normal operating range of the magnetic operator.

2. The smart switch of claim 1 wherein the at least one magnetic sensor comprises at least one magnetoresistive sensor.

3. The smart switch of claim 1 wherein the at least one magnetic sensor comprises first, second, and third magnetic sensors located so as to sense movement of the magnetic operator, and wherein the processor is arranged to process respective outputs of the first, second, and third magnetic sensors so as to detect a right over travel range of the magnetic operator, a left over travel range of the magnetic operator, and a normal operating range of the magnetic operator.

4. The smart switch of claim 3 wherein the first, second, and third magnetic sensors comprise corresponding first, second, and third magnetoresistive sensors.

5. The smart switch of claim 3 wherein the processor comprises an analog processor.

6. The smart switch of claim 5 wherein the processor is arranged to process the combined output so that the combined output has a substantially flat left over travel voltage versus position range, a substantially flat right over travel voltage versus position range, and a sloped normal operating voltage versus position range between the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

7. The smart switch of claim 5 wherein the analog processor comprises:

a first comparator coupled to the first magnetic sensor;

an amplifier coupled to the second magnetic sensor;

a second comparator coupled to the third magnetic sensor; and

,

a logical gate coupled to the amplifier and the first and second comparators.

8. The smart switch of claim 7 wherein the processor is arranged to process the combined output so that the combined output has a substantially flat left over travel voltage versus position range, a substantially flat right over travel voltage versus position range, and a sloped normal operating voltage versus position range between the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

9. The smart switch of claim 3 wherein the processor comprises a digital processor.

10. The smart switch of claim 9 wherein the processor is arranged to process the combined output so that the combined output has a substantially flat left over travel voltage versus position range, a substantially flat right over travel voltage versus position range, and a sloped normal operating voltage versus position range between the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

11. The smart switch of claim 9 wherein the digital processor comprises a microprocessor.

12. The smart switch of claim 11 wherein the processor is arranged to process the combined output so that the combined output has a substantially flat left over travel voltage versus position range, a substantially flat right over travel voltage versus position range, and a sloped normal operating voltage versus position range between the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

13. The smart switch of claim 1 wherein the processor comprises an analog processor.

14. The smart switch of claim 13 wherein the processor is arranged to process the combined output so that the combined output has a substantially flat left over travel voltage versus position range, a substantially flat right over travel voltage versus position range, and a sloped normal operating voltage versus position range between the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

15. The smart switch of claim 13 wherein the analog processor comprises:

a first comparator coupled to the magnetic sensor;

an amplifier coupled to the magnetic sensor;

a second comparator coupled to the magnetic sensor; and

,

a logical gate coupled to the amplifier and the first and second comparators.

16. The smart switch of claim 15 wherein the processor is arranged to process the combined output so that the combined output has a substantially flat left over travel voltage versus position range, a substantially flat right over travel voltage versus position range, and a sloped normal operating voltage versus position range between the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

17. The smart switch of claim 1 wherein the processor comprises a digital processor.

18. The smart switch of claim 17 wherein the processor is arranged to process the combined output so that the combined output has a substantially flat left over travel voltage versus position range, a substantially flat right over travel voltage versus position range, and a sloped normal operating voltage versus position range between the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

19. The smart switch of claim 17 wherein the digital processor comprises a microprocessor.

20. The smart switch of claim 19 wherein the processor is arranged to process the combined output so that the combined output has a substantially flat left over travel voltage versus position range, a substantially flat right over travel voltage versus position range, and a sloped normal operating voltage versus position range between the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

21. The smart switch of claim 1 wherein the processor is arranged to process the combined output so that the combined output has a substantially flat left over travel voltage versus position range, a substantially flat right over travel voltage versus position range, and a sloped normal operating voltage versus position range between the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

22. The smart switch of claim 1 wherein the processor comprises an ASIC.

23. The smart switch of claim 1 wherein the processor is arranged to process the output of the magnetic sensor so as to detect a right over travel range of the magnetic operator, a left over travel range of the magnetic operator, and a normal operating range of the magnetic operator.

24. The smart switch of claim 1 wherein the processor is arranged to perform self-diagnostics on the smart switch.

25. The smart switch of claim 24 wherein the self-diagnostics include determining that a failure has occurred when the processor detects that the output from the magnetic sensor is below a predetermined threshold.

26. The smart switch of claim 24 wherein the self-diagnostics include determining that a failure has occurred when an output from the magnetic sensor is not in accord with a predetermined pattern.

27. The smart switch of claim 24 wherein the processor comprises high temperature electronics.

28. The smart switch of claim 1 wherein the processor is arranged to provide temperature compensation to an output of the magnetic sensor.

29. A smart switch comprising:

a magnetic operator;

first, second, and third magnetoresistive sensors located to sense movement of the magnetic operator; and

,

a processor arranged to process outputs of the first, second, and third magnetoresistive sensors so as to detect right and left over travel ranges and a normal operating range of the magnetic operator.

30. The smart switch of claim 29 wherein the processor is arranged to process the combined output so that the combined output has a substantially flat left over travel voltage versus position range, a substantially flat right over travel voltage versus position range, and a sloped normal operating voltage versus position range between the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

31. The smart switch of claim 29 wherein the processor comprises a microprocessor.

32. The smart switch of claim 29 wherein the processor comprises an ASIC.

33. The smart switch of claim 29 wherein the processor is arranged to determine a failure when the processor detects that the output from at least one of the first, second, and third magnetoresistive sensors is below a predetermined threshold.

34. The smart switch of claim 29 wherein the processor comprises:

a first comparator coupled to the first magnetoresistive sensor;

an amplifier coupled to the second magnetoresistive sensor;

a second comparator coupled to the third magnetoresistive sensor; and

,

a logical gate coupled to the amplifier and the first and second comparators.

35. The smart switch of claim 29 wherein the processor is arranged to provide temperature compensation to an output of the first, second, and third magnetoresistive sensors.

36. A smart switch comprising:

a magnetic operator;

a single magnetoresistive sensor located to sense movement of the magnetic operator; and

,

a processor arranged to process an output of the single magnetoresistive sensor so as to detect an over travel range and a normal operating range of the magnetic operator.

37. The smart switch of claim 36 wherein the processor is arranged to process the output of the single magnetoresistive sensor so as to detect a right over travel range of the magnetic operator, a left over travel range of the magnetic operator, and a normal operating range of the magnetic operator.

38. The smart switch of claim 36 wherein the processor is arranged to process the output of the single magnetoresistive sensor so that the output has a substantially flat left over travel voltage versus position range, a substantially flat right over travel voltage versus position range, and a sloped normal operating voltage versus position range between the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

39. The smart switch of claim 36 wherein the processor comprises first and second comparators to produce the substantially flat left over travel voltage versus position range and the substantially flat right over travel voltage versus position range.

40. The smart switch of claim 36 wherein the processor is arranged to determine a failure when the processor detects that the output from the single magnetoresistive sensor is below a predetermined threshold.

41. The smart switch of claim 36 wherein the processor comprises a microprocessor.

42. The smart switch of claim 36 wherein the processor comprises an ASIC.

43. The smart switch of claim 36 wherein the processor is arranged to provide temperature compensation to an output of the single magnetoresistive sensor.