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. 04, 2002
Filed:
Jul. 19, 2000
Ray Garcia, Boca Raton, FL (US);
Will E. Hamel, Parkland, FL (US);
Kendall A. Honeycutt, Boca Raton, FL (US);
Stephen E. Still, Lake Worth, FL (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Apparatus for monitoring fan speeds within a computing system includes a tachometer turning with the fan, providing a tachometer signal including a number of pulses during each revolution of the fan. This tachometer signal is provided as an input to a signal generator in the form of a flip-flop, which generates a square-wave signal having transitions between high and low levels corresponding to tachometer signal pulses. The square-wave signals are provided as inputs to separate input ports of a microprocessor. These input ports are sequentially sampled at a rate providing at least two samples per period of the fastest square-wave signal, so that transitions of each square wave signal during a predetermined time interval can be detected and counted. For each input port, the number of counted transitions is compared to a stored acceptable value to establish whether the fan is operating in an acceptable speed range.