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:
Feb. 25, 2003
Filed:
Feb. 23, 2000
Yasuhiro Nonobe, Aichi-ken, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
In a polymer electrolyte fuel cell system, a condition of humidification of electrolyte membranes is precisely determined, and adjustment is performed so that the condition of humidification of the electrolyte membranes substantially remains within a proper range. The system determines a condition of humidification of the electrolyte membranes of the fuel cell based on a differential value of the resistance of the fuel cell detected by a resistance detector when the electric current outputted by the fuel cell equals a predetermined value. The current from the cell is detected by an ammeter. The fuel cell is formed by stacking electrically conductive electrodes and separators, and proton-conductive electrolyte membranes. The electric conductivity of the electrodes and the separators is not affected by the humidification condition thereof, whereas the proton-conductivity of the electrolyte membranes greatly changes depending on the condition of humidification thereof. Therefore, the changing rate of the resistance of the fuel cell directly represents the changing rate of the proton-conductivity of the electrolyte membranes, so that the humidification condition of the electrolyte membranes can be precisely determined.