The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 12, 2024
Filed:
Dec. 23, 2021
Seiko Epson Corporation, Tokyo, JP;
Toshihiko Katayama, Yamagata, JP;
SEIKO EPSON CORPORATION, , JP;
Abstract
An abnormality detection circuit includes a first voltage detection circuit to which a voltage is applied from an AC power source when a first relay contact is closed and a second voltage detection circuit to which a voltage is applied from the AC power source when a second relay contact is closed. One end of the first voltage detection circuit is connected to the AC power source via the second wiring line while passing through no other switch. One end of the second voltage detection circuit is connected to the AC power source via the first wiring line while passing through no other switch. Abnormalities of the first and second relay contacts are detected by comparing the voltage applied to a comparative voltage detection circuit with each of the voltages applied to the first and second voltage detection circuits, respectively.