ALEXANDRIA, Va., June 10 -- United States Patent no. 12,293,890, issued on May 6, was assigned to PHOENIX CONTACT GMBH & Co. KG (Blomberg, Germany).
"Contact monitoring apparatus for a three-pole changeover contact" was invented by Christian Reinhold (Hameln, Germany) and Peter Scholz (Brakel, Germany).
According to the abstract* released by the U.S. Patent & Trademark Office: "A contact monitoring means for monitoring an electrical, three-pole changeover contact includes: a signal generator, which generates a monitoring signal; a coupling means, which is connected downstream from the signal generator; a sensing circuit, which is connected downstream from the coupling means and which is coupled or can be coupled to the changeover contact....