US 12,422,484 B2
Detecting welded relay contacts using electrical pulse
David Elmiger, Hitzkirch (CH); Kyle B. Adkins, Oak Creek, WI (US); Andrew E. Carlson, Franklin, WI (US); and David M. Messersmith, Kenosha, WI (US)
Assigned to Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US)
Filed by Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US)
Filed on Jun. 21, 2023, as Appl. No. 18/338,870.
Prior Publication US 2024/0426912 A1, Dec. 26, 2024
Int. Cl. G01R 31/327 (2006.01)
CPC G01R 31/3278 (2013.01) 20 Claims
OG exemplary drawing
 
1. A system, comprising:
a relay system, comprising a plurality of relays each having a first contact on an input side of the respective relay, the input side coupled to a power source, and a second contact on a load side of the respective relay coupled to a load, wherein the load sides of each of the respective relays are coupled through their respective loads; and
a controller, comprising:
one or more processors; and
a memory having stored thereon instructions that, upon execution by the one or more processors, cause the one or more processors to perform a weld detection check comprising:
transmit a close signal to a first relay of the plurality of relays, wherein the close signal is configured to close the first contact and the second contact of the first relay;
transmit a pulse signal to a second relay of the plurality of relays, wherein the pulse signal is configured to have a sufficient electrical magnitude and duration to close the second relay when the second relay has an electrical weld of one of the first contact and the second contact of the second relay and the pulse signal is configured to have an insufficient electrical magnitude and duration to close the first contact and the second contact of the second relay when the second relay has no electrical weld;
measure a current flow through the second relay in response to the pulse signal; and
based on the current flow through the second relay, determine whether the electrical weld of the one of the first contact and the second contact of the second relay exists.