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:
Jul. 21, 2009
Filed:
Mar. 12, 2007
Richard M. Breese, Los Angeles, CA (US);
Thomas P. O'meara, Venice, CA (US);
Stanley K. Fujii, Torrance, CA (US);
Bernd Peter Elgas, Hilbersheim, DE;
Stephen Raiser, Wiesbaden, DE;
Richard M. Breese, Los Angeles, CA (US);
Thomas P. O'Meara, Venice, CA (US);
Stanley K. Fujii, Torrance, CA (US);
Bernd Peter Elgas, Hilbersheim, DE;
Stephen Raiser, Wiesbaden, DE;
GM Global Technology Operations, Inc., Detroit, MI (US);
Abstract
Methods and apparatus are provided for monitoring a coolant conductivity of a fuel cell supplying power via positive and negative buses. The method includes measuring a first voltage of the positive bus, measuring a second voltage of the negative bus, applying a resistance between the positive bus and a reference potential, measuring a third voltage of the positive bus after a period of applying the resistance, and determining an isolation resistance based on the measured voltages. The isolation resistance is a function of the coolant conductivity.