US 11,742,163 B2
Welding detection device and welding detection method
Shinichi Katayama, Kyoto (JP); and Hiroshi Tsuji, Kusatsu (JP)
Assigned to OMRON CORPORATION, Kyoto (JP); and OWL SOLUTION CO., LTD., Shiga (JP)
Appl. No. 17/781,709
Filed by OMRON Corporation, Kyoto (JP); and OWL SOLUTION CO., LTD., Kusatsu (JP)
PCT Filed Nov. 16, 2020, PCT No. PCT/JP2020/042610
§ 371(c)(1), (2) Date Jun. 2, 2022,
PCT Pub. No. WO2021/131394, PCT Pub. Date Jul. 1, 2021.
Claims priority of application No. 2019-234596 (JP), filed on Dec. 25, 2019.
Prior Publication US 2023/0005686 A1, Jan. 5, 2023
Int. Cl. H02H 7/00 (2006.01); H01H 47/00 (2006.01); H02H 7/20 (2006.01)
CPC H01H 47/002 (2013.01) [H02H 7/20 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A welding detection device configured to detect welding in a main relay, the main relay being configured to open and close a connection between a load and a power supply, the power supply being configured to supply AC power to the load, the welding detection device comprising:
a first circuit including a detection element configured to detect a current, the first circuit being connected to a first line and a second line, the first line being configured to connect the power supply and the main relay, the second line being configured to connect the load and the main relay;
a first circuit power supply configured to supply a direct current to the first circuit; and
a second circuit connected to the first circuit, the second circuit being configured to detect a voltage difference between the first line and the second line,
the first circuit configured to detect welding in the main relay based on whether or not a current from the first circuit power supply has flowed to the detection element through the main relay when the main relay is controlled to be in an open state from a closed state, and
the second circuit configured to cut off the first circuit only when the voltage difference is present between the first line and the second line while the main relay is controlled to be in the open state from the closed state.