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:
Oct. 11, 2005
Filed:
Jul. 25, 2001
Applicant:
Brian Wells, Vancouver, CA;
Inventor:
Brian Wells, Vancouver, CA;
Assignee:
Ballard Power Systems Inc., Burnaby, CA;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H01M008/04 ; H01M008/24 ;
U.S. Cl.
CPC ...
Abstract
A respective bipolar junction transistor is coupled across pairs of fuel cells in a fuel cell stack to monitor the voltage across each fuel cell pairs for a drop in voltage below a threshold voltage. A respective optoisolator coupled to each of the transistors produces a digital signal corresponding to the status of the respective pair of fuel cells. An 'AND' circuit produces a single digital signal corresponding to the status of one or more pairs of fuel cells.