Active tester for vehicle circuit evaluation

• US 7,209,850 B2
• Filed: 08/03/2004
• Issued: 04/24/2007
• Est. Priority Date: 08/03/2004
• Status: Expired due to Fees

• Current Assignee: Snap-On Incorporated
• Original Assignee: Snap-On Incorporated
• Inventors: Brott, Alejandro P., Thibedeau, Dennis
• Primary Examiner(s): Barlow, Jr.; John E.
• Assistant Examiner(s): KUNDU, SUJOY K
• Application Number:
  US10/909,367
• Publication Number:
  US 20060031035A1
• Time in Patent Office: 994 Days
• Field of Search: 702/117
• US Class Current: 702/117
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00

Abstract

An active tester for vehicle circuit evaluation includes a signal source for generating a dynamic signal, such as an AC current, for injecting to a circuit under test. The tester includes a data storage device for storing at least one test parameter and a data processor for processing data. In operation, the data processor controls to apply the dynamic signal to the separated points of the circuit via the first set of terminals. The response of the circuit under test to the applied dynamic signal is measured. The data processor determines a dynamic parameter of the circuit under test as a function of the dynamic signal and the response. The data process then generates a test result related to the characteristics of the circuit as a function of the at least one test parameter and the determined dynamic parameter. The test result is compared with specification values to determine whether the circuit under test works normally.

Claims

1. A tester for testing a circuit including a first device, a second device and a conductor external to the first device and the second device, attaching to the first device and the second device at separated points, the tester comprising:

a first set of terminals and a second set of terminals;

a signal source for generating a dynamic signal;

a first set of leads connectable at respective first ends to the separated points of the circuit and connectable at respective second ends to the first set of terminals;

a second set of leads connectable at respective first ends to the separated points of the circuit and connectable at respective second ends to the second set of terminals;

a data storage device for storing at least one test parameter; and

a data processor, coupled to the data storage device and the signal source, configured to perform the steps of;

controlling application of the dynamic signal to the separated points of the circuit via the first set of terminals;

obtaining a response signal from the second set of terminals representing a response of the circuit between the separated points to the applied dynamic signal;

determining a dynamic parameter of the circuit between the separated points as a function of the dynamic signal;

accessing the at least one test parameter stored in the data storage device;

calculating a value related to the characteristics of the conductor between the separated points, wherein the calculated value is a function of the at least one test parameter and the determined dynamic parameter; and

generating a result related to the characteristics of the conductor according to the calculated value.

2. The tester of claim 1, wherein the dynamic parameter is selected from a group consisting of the impedance, the conductance, the resistance and the admittance of the circuit between the separated points.

3. The tester of claim 1, wherein:

the at least one test parameter includes a plurality of test parameters; and

for each of the plurality of test parameters, the data processor is configured to generate a respective test result representing characteristics of the circuit between the separated points as a function of each of the plurality of test parameters and the determined dynamic parameter.

4. The tester of claim 1, wherein:

the at least one test parameter includes a plurality of test parameters; and

the data processor is configured to perform the steps of;

receiving a user selection of one of the plurality of the tester parameters; and

generating the test result representing characteristics of the circuit between the separated points as a function of the selected one of the plurality of test parameters and the determined dynamic parameter.

5. The tester of claim 4 further comprising an input device, coupled to the data processor, for receiving the user selection.

6. The tester of claim 1, wherein the at least one test parameter is pre-stored in the data storage device or obtained from a measurement previously performed by the tester.

7. The tester of claim 1, wherein the at least one test parameter is a current flowing through the circuit between the separated points.

8. The tester of claim 7 further comprising a non-contact current sensor coupled to the data processor, for measuring the current;

and the data processor is configured to control storing of the measured current in the data storage device.

9. The tester of claim 8, wherein the non-contact current sensor is a hall effect current sensor.

10. The tester of claim 1, wherein:

the dynamic parameter represents the impedance of the circuit between the separated points;

the dynamic signal is an AC signal;

the test parameter represents a current; and

the test result represents a voltage across the separated points calculated based on the current and the impedance.

11. The tester of claim 1 further comprising a display coupled to the data processor for displaying the test result.

12. The tester of claim 1, wherein the data processor is further configured to performed the steps of:

accessing specification data from the data storage device or a remote data storage device coupled to the tester through a data link, wherein the specification data relates to the specification value corresponding to the circuit;

comparing the test result with the accessed specification data; and

generating a diagnostic result based on a result of the comparing step.

13. The tester of claim 12, wherein the specification value corresponds to the test parameter.

14. The tester of claim 13, wherein:

the dynamic parameter represents the impedance of the circuit between the separated points;

the dynamic signal is an AC signal;

the at least one test parameter is a current;

the test result represents a voltage across the separated points of the circuit corresponding to the test parameter; and

the specification data represents a specification voltage value corresponding to the at least one test parameter.

56. The tester of claim 1, wherein the data processor is configured to perform a further step of generating a test result based on the value and a specification value.

64. The tester of claim 1, wherein the first device is a battery and the second device is a device other than a battery.

15. In a tester including a signal source for generating a dynamic signal, and a data processor configured to apply the dynamic signal to a circuit via separated points of the circuit, and determine a dynamic parameter of the circuit between the separated points as a function of the dynamic signal applied to the circuit, wherein the circuit includes a first device, a second device and a conductor external to the first device and the second device, attaching to the first device and the second device at the separated points, the improvement comprising:

a data storage device, accessible by the data processor, for storing the determined dynamic parameter and at least one test parameter; and

the data processor configured to perform the steps of;

accessing the at least one test parameter stored in the data storage device;

accessing the determined dynamic parameter stored in the data storage device;

calculating a value related to characteristics of the conductor, wherein the calculated value is a function of the at least one test parameter and the determined dynamic parameter; and

providing a result related to the characteristics of the conductor according to the calculated value.

16. The method of claim 15, wherein the dynamic parameter is selected from a group consisting of the impedance, the conductance, the resistance and the admittance of the circuit between the separated points.

57. The tester of claim 15, wherein the data processor is configured to perform a further step of generating a test result based on the value and a specification value.

65. The tester of claim 15, wherein the first device is a battery and the second device is a device other than a battery.

17. A method for determining characteristics of a circuit, wherein the circuit includes a first device, a second device and a conductor external to the first device and the second device, connecting the first device and the second device at separated points, the method comprising the machine-implemented steps of:

generating a dynamic signal;

applying the dynamic signal to the separated points of the circuit;

determining a response of the circuit between the separated points to the applied dynamic signal;

determining a dynamic parameter of the circuit between the separated points based on the dynamic signal and the determined response;

accessing at least one test parameter;

calculating a value related to the characteristics of the conductor between the separated points, wherein the calculated value is a function of the dynamic parameter of the circuit between the separated points and the at least one test parameter; and

providing a result related to the characteristics of the conductor according to the calculated value.

18. The method of claim 17, wherein the at least one test parameter includes a plurality of test parameters.

19. The method of claim 18 further comprising the step of receiving a user selection of one of the plurality of test parameters, wherein the test result is generated as a function of the selected one of the plurality of test parameters and the dynamic parameter of the circuit between the separated points.

20. The method of claim 17, wherein the dynamic parameter is selected from a group consisting of the impedance, the conductance, the resistance and the admittance of the circuit.

58. The method of claim 17 further comprising the step of generating a test result based on the value and a specification value.

66. The method of claim 17, wherein the first device is a battery and the second device is a device other than a battery.

21. A method for testing characteristics of a circuit, the method comprising the machine-implemented steps of:

applying an AC signal to the circuit via separated points of the circuit;

obtaining a response signal representing a response of the circuit between the separated points to the applied AC signal;

calculating the impedance of the circuit between the separated points based on the AC signal and the response signal;

storing the impedance of the circuit between the separated points;

accessing a preset test parameter representing a current; and

providing a predicted voltage between the separated points of the circuit in response to the current based on the preset test parameter and the impedance.

22. The method of claim 21 further comprising the steps of:

accessing specification data representing a specification voltage value corresponding to the current;

comparing the calculated voltage with the specification voltage; and

generating a diagnostic result based on a result of the comparing step.

23. The method of claim 22, wherein the step of generating the diagnostic result includes the steps of:

determining a difference between the calculated voltage and the specification voltage value obtained in the comparing step;

accessing threshold data including information related to an acceptable difference;

comparing the difference between the calculated voltage and the specification voltage value with the acceptable difference; and

generating the diagnostic result based on a result of the step of comparing the difference between the calculated voltage and the specification voltage value with the acceptable difference.

24. The method of claim 21 further comprising the step of outputting the diagnostic result.

25. A tester for testing a circuit including a first device, a second device and a conductor external to the first device and the second device, connecting the first device and the second device at separated points, the tester comprising:

a first set of signal coupling means and a second set of signal coupling means;

means for generating a dynamic signal;

a first set of connecting means for connecting the separated points of the circuit to the first set of signal coupling means;

a second set of connecting means for connecting the separated points of the circuit to the second set of signal coupling means;

data storage means for storing at least one test parameter; and

data processing means, coupled to the data storage means and the means for generating the dynamic signal, for performing the steps of;

controlling application of the dynamic signal to the separated points of the circuit via the first set of signal coupling means;

obtaining a response signal from the second set of signal coupling means representing a response of the circuit between the separated points to the applied dynamic signal;

determining a dynamic parameter of the circuit between the separated points as a function of the dynamic signal;

accessing the at least one test parameter stored in the data storage means;

calculating a value related to the characteristics of the conductor between the separated points, wherein the calculated value is a function of the at least one test parameter and the determined dynamic and

generating a result related to the characteristics of the conductor according to the calculated value.

26. The tester of claim 25, wherein the dynamic parameter is selected from a group consisting of the impedance, the conductance, the resistance and the admittance of the circuit between the separated points.

27. The tester of claim 25, wherein:

the at least one test parameter includes a plurality of test parameters; and

for each of the plurality of test parameters, the data processing means is configured to generate a respective test result representing characteristics of the circuit between the separated points as a function of each of the plurality of test parameters and the determined dynamic parameter.

28. The tester of claim 25, wherein:

the at least one test parameter includes a plurality of test parameters; and

the data processing means is further configured to perform the steps of;

receiving a user selection of one of the plurality of the tester parameters; and

generating the test result representing characteristics of the circuit between the separated points as a function of the selected one of the plurality of test parameters and the determined dynamic parameter.

29. The tester of claim 28 further comprising input means for receiving the user selection.

30. The tester of claim 25, wherein:

the dynamic parameter represents the impedance of the circuit between the separated points;

the dynamic signal is an AC signal;

the test parameter represents a current; and

the test result represents a voltage across the separated points calculated based on the current and the impedance.

31. The tester of claim 25 further comprising display means for displaying the test result.

32. The tester of claim 25, wherein the data processing means is further configured to performed the steps of:

accessing specification data related to the circuit from the data storage means or a remote data storage means coupled to the tester through a data link, wherein the specification data includes the specification value;

comparing the test result with the accessed specification data; and

generating a diagnostic result based on a result of the comparing step.

33. The tester of claim 25, wherein:

the dynamic parameter represents the impedance of the circuit between the separated points;

the dynamic signal is an AC signal;

the at least one test parameter is a current;

the test result represents a voltage across the separated points of the circuit corresponding to the test parameter; and

the specification data represents a specification voltage value corresponding to the at least one test parameter.

59. The tester of claim 25, wherein the data processing means further performs the step of generating a test result based on the value and a specification value.

67. The tester of claim 25, wherein the first device is a battery and the second device is a device other than a battery.

34. A tester for testing a circuit including a first device, a second device and a conductor external to the first device and the second device, connecting the first device and the second device at separated points, the tester comprising:

at least one first terminal and at least one second terminal;

a signal source for generating a dynamic signal;

a data storage device for storing at least one test parameter; and

a data processor, coupled to the data storage device and the signal source, configured to perform the steps of;

controlling application of the dynamic signal to the separated points via the at least one first terminal;

obtaining a response signal from the at least one second terminal representing a response of the circuit between the separated points to the applied dynamic signal;

determining a dynamic parameter of the circuit between the separated points as a function of the dynamic signal;

accessing the at least one test parameter stored in the data storage device; and

calculating a value related to the characteristics of the conductor between the separated points, wherein the calculated value is a function of the at least one test parameter and the determined dynamic parameter; and

generating a result related to the characteristics of the conductor according to the calculated value.

35. The tester of claim 34, wherein:

the dynamic parameter represents the impedance of the circuit between the separated points;

the dynamic signal is an AC signal;

the test parameter represents a current; and

the test result represents a voltage across the separated points calculated based on the current and the impedance.

36. The tester of claim 34, wherein the data processor is further configured to performed the steps of

accessing specification data related to the circuit from the data storage device or a remote data storage device coupled to the tester through a data link, wherein the specification data includes the specification value;

comparing the test result with the accessed specification data; and

generating a diagnostic result based on a result of the comparing step.

37. The tester of claim 34, wherein the data processor is further configured to perform the steps of:

responsive to the diagnostic result representing that the circuit is abnormal, accessing specification data related to a required dynamic parameter of the circuit;

comparing the determined dynamic parameter of the circuit with the required dynamic parameter; and

determining a condition of the measured dynamic parameter of the circuit based on a result of the step of comparing the determined dynamic parameter of the circuit with the required dynamic parameter.

38. The tester of claim 37, wherein the data processor is further configured to perform the steps of:

responsive to the measured dynamic parameter of the circuit being determined as abnormal, generating an output indicating that the measured dynamic parameter of the circuit is abnormal; and

responsive to the measured dynamic parameter of the circuit being determined as normal, generating an output indicating that the measured dynamic parameter of the circuit is normal.

60. The tester of claim 34, wherein the data processor is configured to perform the step of generating a test result based on the value and a specification value.

68. The tester of claim 34, wherein the first device is a battery and the second device is a device other than a battery.

39. A tester for testing a circuit including a first device, a second device and a conductor external to the first device and the second device, connecting the first device and the second device at separated points, the tester comprising:

first means for coupling signals;

means for generating a dynamic signal;

data storage means for storing at least one test parameter; and

data processing means, coupled to the data storage means and the means for generating the dynamic signal, configured to perform the steps of;

controlling application of the dynamic signal to the separated points via the signal coupling means;

obtaining a response signal from the signal coupling means from the separated points representing a response of the circuit between the separated points to the applied dynamic signal;

determining a dynamic parameter of the circuit between the separated points as a function of the dynamic signal;

accessing the at least one test parameter stored in the data storage means;

calculating a value related to the characteristics of the conductor between the separated points, wherein the calculated value is a function of the at least one test parameter and the determined dynamic parameter; and

generating a result related to the characteristics of the conductor according to the calculated value.

40. The tester of claim 39, wherein:

the dynamic parameter represents the impedance of the circuit between the separated points;

the dynamic signal is an AC signal;

the test parameter represents a current; and

the test result represents a voltage across the separated points calculated based on the current and the impedance.

41. The tester of claim 39, wherein the data processing means is further configured to performed the steps of:

accessing specification data related to the circuit from the data storage device or a remote data storage device coupled to the tester through a data link, wherein the specification data includes the specification value;

comparing the test result with the accessed specification data; and

generating a diagnostic result based on a result of the comparing step.

42. The tester of claim 39, wherein the data processing means is further configured to perform the steps of:

responsive to the diagnostic result representing that the circuit is abnormal, accessing specification data related to a required dynamic parameter of the circuit;

comparing the determined dynamic parameter of the circuit with the required dynamic parameter; and

determining a condition of the measured dynamic parameter of the circuit based on a result of the step of comparing the determined dynamic parameter of the circuit with the required dynamic parameter.

43. The tester of claim 42, wherein the data processing means is further configured to perform the steps of:

responsive to the measured dynamic parameter of the circuit being determined as abnormal, generating an output indicating that the measured dynamic parameter of the circuit is abnormal; and

responsive to the measurement dynamic parameter of the circuit being determined as normal, generating an output indicating that the measured dynamic parameter of the circuit is normal.

61. The tester of claim 39, wherein the data processing means is configured to perform the step of generating a test result based on the value and a specification value.

69. The tester of claim 39, wherein the first device is a battery and the second device is a device other than a battery.

44. A method for testing a circuit including a first device, a second device and a conductor external to the first device and the second device, connecting the first device and the second device at separated points, the method comprising the steps of:

applying the dynamic signal to the circuit;

obtaining a response signal representing a response of the circuit between the separated points to the applied dynamic signal;

determining a dynamic parameter of the circuit between the separated points as a function of the dynamic signal;

accessing at least one test parameter;

calculating a value related to the characteristics of the conductor between the separated points, wherein the calculated value is a function of the at least one test parameter and the determined dynamic parameter; and

providing a result related to the characteristics of the conductor according to the calculated value.

45. The method of claim 44, wherein:

the dynamic parameter represents the impedance of the circuit between the separated points;

the dynamic signal is an AC signal;

the test parameter represents a current; and

the test result represents a voltage across the separated points calculated based on the current and the impedance.

46. The method of claim 44 further comprising the steps of:

accessing specification data related to the circuit, wherein the specification data includes the specification value;

comparing the test result with the accessed specification data; and

generating a diagnostic result based on a result of the comparing step.

47. The tester of claim 44 further comprising the steps of:

responsive to the diagnostic result representing that the circuit is abnormal, accessing specification data related to a required dynamic parameter of the circuit;

comparing the determined dynamic parameter of the circuit with the required dynamic parameter; and

determining a condition of the measured dynamic parameter of the circuit based on a result of the step of comparing the determined dynamic parameter of the circuit with the required dynamic parameter.

48. The tester of claim 47 further comprising the steps of:

responsive to the measured dynamic parameter of the circuit being determined as abnormal, generating an output indicating that the measured dynamic parameter of the circuit is abnormal; and

responsive to the measurement dynamic parameter of the circuit being determined as normal, generating an output indicating that the measured dynamic parameter of the circuit is normal.

62. The method of claim 44 further comprising the step of generating a test result based on the value and a specification value.

70. The method of claim 44, wherein the first device is a battery and the second device is a device other than a battery.

49. In a tester including a signal source for generating a dynamic signal, and a data processor configured to apply the dynamic signal to a circuit between separated points of the circuit, and determine a dynamic parameter of the circuit as a function of the dynamic signal applied to the circuit, wherein the circuit includes a first device, a second device and a conductor external to the first device and the second device, connecting the first device and the second device at the separated points, the improvement comprising:

a data storage device, accessible by the data processor, for storing the determined dynamic parameter and at least one test parameter; and

the data processor configured to perform the steps of;

accessing the at least one test parameter stored in the data storage device;

accessing the determined dynamic parameter stored in the data storage device;

calculating a value related to the characteristics of the conductor between the separated points, wherein the calculated value is a function of the at least one test parameter and the determined dynamic parameter; and

generating a result related to the characteristics of the conductor according to the calculated value.

50. The tester of claim 49, wherein:

the at least one test parameter includes a plurality of test parameters; and

the data processing means is further configured to perform the steps of;

receiving a user selection of one of the plurality of the tester parameters; and

generating the test result as a function of the selected one of the plurality of test parameters and the determined dynamic parameter.

63. The tester of claim 49, wherein the data processor is configured to perform the step of generating a test result based on the value and a specification value.

71. The tester of claim 49, wherein the first device is a battery and the second device is a device other than a battery.

51. A tester for testing a circuit comprising:

at least one first terminal and at least one second terminal;

a signal source for generating a dynamic signal;

a data storage device for storing specification information; and

a data processor, coupled to the data storage device and the signal source, configured to perform the steps of;

controlling application of the dynamic signal to the circuit via the at least one first terminal;

obtaining a response signal from the at least one second terminal representing a response of the circuit to the applied dynamic signal;

determining a dynamic parameter of the circuit as a function of the dynamic signal;

accessing the specification information stored in the data storage device;

comparing the specification information and the dynamic parameter; and

indicating a connection condition of the circuit based on a result of the comparing step.

52. A tester comprising:

a first set of terminals and a second set of terminals;

a signal source for generating a dynamic signal;

a first set of leads connectable at respective first ends to separated points of a circuit and connectable at respective second ends to the first set of terminals;

a second set of leads connectable at respective first ends to the separated points of the circuit and connectable at respective second ends to the second set of terminals;

a data storage device for storing at least one test parameter; and

a data processor, coupled to the data storage device and the signal source, configured to perform the steps of;

controlling application of the dynamic signal to the separated points of the circuit via the first set of terminals;

obtaining a response signal from the second set of terminals representing a response of the circuit between the separated points to the applied dynamic signal;

determining a dynamic parameter of the circuit between the separated points as a function of the dynamic signal;

accessing the at least one test parameter stored in the data storage device;

generating a test result related to the characteristics of the circuit between the separated points as a function of the dynamic parameter and the at least one test parameter, wherein the test result relates to a connection condition of the circuit; and

indicating the connection condition.

53. A method for determining characteristics of a circuit, the method comprising the machine-implemented steps of:

generating a dynamic signal;

applying the dynamic signal to separated points of the circuit;

determining a response of the circuit between the separated points to the applied dynamic signal;

determining a dynamic parameter of the circuit between the separated points based on the dynamic signal and the determined response;

accessing at least one test parameter;

generating a test result related to the characteristics of the circuit as a function of the dynamic parameter of the circuit between the separated points and the at least one test parameter, wherein the test result relates to a connection condition of the circuit; and

providing the connection condition.

54. A tester comprising:

at least one first terminal and at least one second terminal;

a signal source for generating a dynamic signal;

a data storage device for storing at least one test parameter; and

a data processor, coupled to the data storage device and the signal source, configured to perform the steps of;

controlling application of the dynamic signal to a circuit via the at least one first terminal;

obtaining a response signal from the at least one second terminal representing a response of the circuit to the applied dynamic signal;

determining a dynamic parameter of the circuit as a function of the dynamic signal;

accessing the at least one test parameter stored in the data storage device;

generating a test result related to the characteristics of the circuit as a function of the at least one test parameter and the determined dynamic parameter, wherein the test result relates to a connection condition of the circuit; and

providing the connection condition.

55. A method for testing a circuit comprising the steps of:

applying the dynamic signal to the circuit;

obtaining a response signal representing a response of the circuit to the applied dynamic signal;

determining a dynamic parameter of the circuit as a function of the dynamic signal;

accessing at least one test parameter;

generating a test result related to the characteristics of the circuit as a function of the at least one test parameter and the determined dynamic parameter, wherein the test result relates to a connection condition of the circuit; and

indicating the connection condition.