Joseph E Schumacher

US Patent:

7483253, Jan 27, 2009

Filed:

May 30, 2006

Appl. No.:

11/442143

Inventors:

Joseph Wilfred Schumacher - East Peoria IL, US

Assignee:

Caterpillar Inc. - Peoria IL

International Classification:

H01H 47/00

US Classification:

361160

Abstract:

A method for detecting actuation of an armature associated with a solenoid includes providing a voltage potential to a solenoid coil associated with the solenoid. The method also includes measuring a current flowing through the solenoid coil. The method further includes switching the voltage potential off when the measured current reaches a predetermined maximum value. The method also includes switching the voltage potential on when the measured current reaches a predetermined minimum value. The method further includes measuring a time period between pulses associated with the switching on and off of the voltage potential. The method also includes comparing the measured time period between pulses with predetermined data indicative of an inductance growth level associated with the coil. The method further includes determining, based on the comparison, a pull-in time of an armature associated with the solenoid.

US Patent:

20110149458, Jun 23, 2011

Filed:

Dec 17, 2009

Appl. No.:

12/640372

Inventors:

Philip J. Thomas - Peoria Heights IL, US
Joseph W. Schumacher - East Peoria IL, US
William J. Love - Dunlap IL, US

Assignee:

Caterpillar Inc. - Peoria IL

International Classification:

H01H 47/00

US Classification:

361160

Abstract:

A method for detecting actuation of an armature associated with a solenoid includes providing a voltage potential to a solenoid coil associated with the solenoid. The method also includes measuring a current flowing through the solenoid coil. The method further includes switching the voltage potential off when the measured current reaches a predetermined maximum value. The method also includes switching the voltage potential on when the measured current reaches a predetermined minimum value. The method further includes measuring a chop period between pulses associated with the switching on and off of the voltage potential. The method also includes analyzing successive chop periods to detect armature movement and armature seating. The method further includes determining, based on the comparison of chop periods, a pull-in time of an armature associated with the solenoid.