US 11,901,145 B2
Systems and methods for detecting welded contacts in an electromagnetic switch system
Kyle B. Adkins, Oak Creek, WI (US); Andrew E. Carlson, Franklin, WI (US); David M. Messersmith, Kenosha, WI (US); and David Elmiger, Hitzkirch (CH)
Assigned to Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US)
Filed by Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US)
Filed on Sep. 27, 2021, as Appl. No. 17/485,734.
Prior Publication US 2023/0101428 A1, Mar. 30, 2023
Int. Cl. H02P 1/10 (2006.01); H01H 47/00 (2006.01); H01H 50/18 (2006.01); H01H 50/44 (2006.01)
CPC H01H 47/002 (2013.01) [H01H 50/18 (2013.01); H01H 50/44 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system, comprising:
a first power source; and
a switching device, comprising:
an armature configured to electrically couple one or more movable contacts to one or more contacts of an electric circuit;
a relay coil configured to receive a current from a second power source, thereby causing the armature to electrically couple the one or more movable contacts to the one or more contacts of the electric circuit or electrically disconnect the one or more movable contacts from the one or more contacts after a period of time; and
a control system configured to perform operations comprising:
transmitting a command to the second power source to provide power to the relay coil with a fixed current profile;
receiving one or more voltage measurements associated with the relay coil during the period of time;
determining that the one or more voltage measurements indicate that the one or more movable contacts are at least partially welded to the one or more contacts of the electric circuit; and
in response to determining that the one or more voltage measurements indicate that the one or more movable contacts are at least partially welded to the one or more contacts of the electric circuit, transmitting an additional command to the second power source to disconnect the current to the relay coil.