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:
Jun. 17, 2025
Filed:
Feb. 05, 2021
Hitachi Astemo, Ltd., Hitachinaka, JP;
Hitachi Astemo, Ltd., Hitachinaka, JP;
Abstract
In a case where a load current flows in an energized state where a power supply is connected to a load, it is assumed that a measured voltage fluctuates due to a voltage drop caused by contact resistance of a relay contact, and thus the relay state cannot be accurately diagnosed. A relay control device that controls a relay connected between a secondary battery and a load device calculates, in a failure diagnosis during energization with the relay being closed, a contact resistance value of the relay based on a voltage applied to the relay and a current flowing through the secondary battery, and determines a first threshold set as a variable value in accordance with a temperature change amount of the relay and compares the calculated contact resistance value with the first threshold to diagnose a failure of the relay.