Solenoid transient variable resistance feedback for effecter position detection

Patent metadata

Field	Value
Publication number	US-9632142-B2
Application number	US-201614990537-A
Country	US
Kind code	B2
Filing date	Jan 7, 2016
Priority date	Jul 20, 2012
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

Feedback from a solenoid is achieved by adding at least one variable resistance in parallel with the solenoid current feedback circuit for position detection. The resistance has current flowing therethrough when a switching device actuated by the solenoid is in one position or transitions from one position to at least one other position. A feedback current may be measured in the current feedback circuit and the position of the switching device in response to actuation thereof by the solenoid may be determined from the measured feedback current.

First claim

The invention claimed is:

1. A switching device position detection system comprising:
a solenoid adapted to generate mechanical energy from an energizing current supplied thereto;
a switching device coupled to the solenoid and adapted to be driven by the mechanical energy generated from the solenoid to move between a first position and at least one second position;
at least one measuring element coupled to the switching device, the at least one measuring element adapted to be engaged by the switching device and to have a measuring current flowing therethrough when the switching device moves to the at least one second position; and
a solenoid driver coupled to the solenoid to supply the energizing current to the solenoid, the solenoid driver coupled to the at least one measuring element to detect the measuring current and configured to identify a fault in the switching device when the energizing current has been supplied to the solenoid and the measuring current is not detected by the solenoid driver.

2. The system of claim 1 , wherein the solenoid driver is adapted to update the energizing current for supply to the solenoid.

3. The system of claim 1 , wherein the solenoid driver is adapted to receive a feedback current comprising a sum of the energizing current and the measuring current when the at least one measuring element has moved to the at least one second position, and compare the feedback current to a predetermined threshold to detect the measuring current.

4. The system of claim 3 , wherein the predetermined threshold corresponds to the energizing current at a time t=t 1 preceding a time t=t 2 at which the switching device has moved to the at least one second position.

5. The system of claim 1 , wherein the at least one measuring element comprises at least one resistor.

6. The system of claim 1 , wherein the switching device is adapted to move between the first position and a plurality of successive second positions.

7. The system of claim 6 , wherein the at least one measuring element comprises a first measuring element, the first measuring element adapted to be engaged by the switching device and to have a first measuring current flowing therethrough when the switching device is in the first position, and a plurality of second measuring elements each adapted to be successively engaged by the switching device and to have a second measuring current flowing therethrough when the switching device is in a corresponding one of the plurality of successive second positions.

8. The system of claim 7 , wherein the second measuring current flowing through a first one of the plurality of second measuring elements is different from the first measuring current and from the second measuring current flowing through a second one of the plurality of second measuring elements.

9. The system of claim 1 , wherein the switching device is adapted to move between a plurality of successive steady state positions and to pass through a transient position when moving between each pair of the plurality of successive steady state positions.

10. The system of claim 9 , wherein the at least one measuring element comprises a plurality of measuring elements each adapted to be temporarily engaged by the switching device and have the measuring current flowing therethrough when the switching device passes through the transient position.

11. A switching device position detection method comprising:
energizing a solenoid by supplying an energizing current from a solenoid driver coupled thereto, thereby actuating a switching device coupled to the solenoid to move between a first position and at least one second position when the solenoid generates mechanical energy in response to being energized;
generating a measuring current through at least one measuring element coupled to the switching device when the switching device moves between the first position and the at least one second position;
detecting the measuring current from the measuring element at the solenoid driver; and
identifying a fault in the switching device when the energizing current has been supplied to the solenoid and the measuring current is not detected by the solenoid driver.

12. The method of claim 11 , wherein detecting the measuring current comprises receiving a feedback current comprising a sum of the energizing current and the measuring current when the at least one measuring element has moved to the at least one second position, and comparing the feedback current to a predetermined threshold.

13. The method of claim 12 , wherein comparing the feedback current to a predetermined threshold comprises comparing the feedback current to the energizing current at a time t=t 1 preceding a time t=t 2 at which the switching device has moved to the at least one second position.

14. The method of claim 11 , further comprising updating the energizing current for supply to the solenoid.

15. The method of claim 11 , wherein energizing the solenoid actuates the switching device to move between the first position and a plurality of successive second positions.

16. The method of claim 15 , wherein generating a measuring current comprises generating the measuring current through a first measuring element coupled to the switching device when the switching device is in the first position and generating the measuring current through each one of a plurality of second measuring elements coupled to the switching device when the switching device is in a corresponding one of the plurality of successive second positions.

17. The method of claim 11 , wherein energizing the solenoid actuates the switching device to move between a plurality of successive steady state positions and to pass through a transient position when moving between each pair of the plurality of successive steady state positions.

18. The method of claim 17 , wherein generating a measuring current comprises generating the measuring current through each one of a plurality of measuring elements coupled to the switching device when the switching device passes through the transient position.

19. A switching device position detection system comprising:
means for energizing a solenoid by supplying an energizing current from a solenoid driver coupled thereto, thereby actuating a switching device coupled to the solenoid to move between a first position and at least one second position when the solenoid generates mechanical energy in response to being energized;
means for generating a measuring current through at least one measuring element coupled to the switching device when the switching device moves between the first position and the at least one second position; and
means for detecting the measuring current from the measuring element at the solenoid driver; and
means for identifying a fault in the switching device when the energizing current has been supplied to the solenoid and the measuring current is not detected by the solenoid driver.

Assignees

• Pratt & Whitney Canada

Inventors

• Day Christopher Bryan

Classifications

• H01H47/002

  Monitoring or fail-safe circuits · CPC title

• G01R31/3278 Primary

  of relays, solenoids or reed switches (measuring contact resistance G01R27/205; high voltage magnetic switches G01R31/3271, G01R31/333; testing electric windings G01R31/72; monitoring of fail safe circuits H01H47/002) · CPC title