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:
Dec. 02, 2003
Filed:
Jan. 11, 2001
Robert Christopher Dixon, Austin, TX (US);
Thoi Nguyen, Austin, TX (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A multiple fan sensing circuit for use with a single fan sense input and method of operation thereof. The multiple fan sensing circuit includes a logic circuit, coupled to the fan sense input, that combines feedback signals from a first fan and a second fan. The first fan generates a tach signal indicative of the first fan operation and the second fan, e.g., a stuck rotor type fan, generates either an ON or OFF signal indicative of the second fan operation. In a related embodiment, the second fan generates a logic high signal in response to a failure in the second fan. In an advantageous embodiment, the logic circuit is a connector and a logic low level in the combined operational signal indicates a failed fan.