SYSTEM AND METHOD FOR DETECTING SENSOR LEAKAGE

• US 20150028883A1
• Filed: 10/14/2014
• Published: 01/29/2015
• Est. Priority Date: 04/28/2009
• Status: Active Grant

• Current Assignee: Textron Innovations Incorporated (Textron Inc)
• Original Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Inventors: FROMAN, GARY
• Granted Patent: US 9,476,928 B2
• Time in Patent Office: Days
• US Class Current: 324/509
• CPC Class Codes: G01R 31/008 on air- or spacecraft, railway rolling stock or sea-going vessels
• CPC Class Codes: G01R 31/2829 Testing of circuits in sensor or actuator systems testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults

Abstract

A test system for testing a sensor system includes a high-impedance resistor for forming a voltage divider with any corrosion or foreign substance that might be present between a signal conductor and a ground conductor. While a voltage is applied across the voltage divider, the voltage can be measured across the high-impedance resistor for determining whether an undesirable amount of conductance exists between the signal wire and ground. The test system also includes switching means for switching between any number of signal wires of a system undergoing testing.

Claims

1. A sensor test system, comprising:

a case configured to house a circuit;

a power source for producing a voltage;

a cable electrically connecting a first sensor to the circuit;

the first sensor comprising multiple connector pins and a grounded connector shell;

wherein the circuit comprises;

a high-impedance resistor connected between the power source and the multiple connector pins;

a return line from the grounded connector shell to the power source, such that the voltage produced from the power source renders a contaminant conductive, in that the contaminant provides conductive path between the multiple connector pins and the grounded connector shell and produces a contamination voltage across the high-impedance resistor, while the contaminant also provides a contaminant resistance;

a first comparator comparing the contamination voltage to a wire fault voltage.

2. The sensor test system of claim 1, wherein the voltage is approximately 28 volts.

3. The sensor test system of claim 1, further comprising:

a second comparator comparing the contamination voltage to a passing sensor voltage.

4. The sensor test system of claim 3, further comprising:

a third comparator comparing the contamination voltage to a dirty sensor voltage;

wherein the dirty sensor voltage is greater than the passing sensor voltage and less than a wire fault voltage.

5. The sensor test system of claim 1, further comprising:

a power source tester;

wherein the battery source tester signals when the voltage produced by the power source is less than 20 volts.

6. The sensor test system of claim 1, further comprising:

a wire fault indicator;

wherein the wire fault indicator illuminates when the contamination voltage is greater than 13 volts.

7. The sensor test system of claim 1, further comprising:

a passing sensor indicator;

wherein the passing sensor indicator illuminates when the contamination voltage is less than 1 volt.

8. The sensor test system of claim 1, further comprising:

a dirty sensor indicator;

wherein the dirty sensor indicator illuminates when the contamination voltage is greater than 1 volt and less than 13 volts.

9. The sensor test system of claim 1, further comprising:

a second sensor connected to the circuit with the cable;

a switch for selectively changing electrical connectivity of the circuit between the first sensor and the second sensor.

10. The sensor test system of claim 1, wherein the high-impedance resistor is between 100 k Ohms and 1M Ohms.

11. The sensor test system of claim 1, wherein the case is metallic.

12. The sensor test system of claim 1, wherein the case is sealed against dust and moisture.

13. The sensor test system of claim 1, further comprising:

filtered pins between the circuit and the first sensor.

14. The sensor test system of claim 1, further comprising:

a self test connector.

15. A method for detecting a leakage in a sensor with a tester, comprising:

using a circuitry in the tester to electrically couple a plurality of connector pins, the connector pins being located in a connector shell;

applying a source voltage to the circuitry, the circuitry including a high-impedance resistor located between the plurality of connector pins and the source voltage, a common connection of the multiple connector pins such that the connector pins remain at a same electrical potential having a single voltage source and a single return path, the circuitry being configured such that a contamination between the connector pins and the connector shell becomes conductive upon applying the source voltage;

comparing a voltage reading across the high-impedance resistor to a wire fault voltage; and

illuminating a wire fault light if the voltage is greater than the wire fault voltage.

16. The method according to claim 15, further comprising:

comparing a voltage reading across the high-impedance resistor to a passing sensor voltage; and

illuminating a pass light if the voltage is less than the passing sensor voltage.

17. The method according to claim 16, further comprising:

comparing a voltage reading across the high-impedance resistor to a dirty sensor voltage; and

illuminating a dirty sensor light if the voltage is greater than the passing sensor voltage and if the voltage is less than the wire fault voltage.

18. The method according to claim 17, wherein the wire fault voltage is 13 volts;

and

wherein the passing sensor voltage is 1 volt.

19. The method according to claim 17, further comprising:

connecting a self test connector.