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. 01, 2008
Filed:
Dec. 27, 2005
Eileen M. Marando, Bellmore, NY (US);
Eileen M. Marando, Bellmore, NY (US);
Standard Microsystems Corporation, Hauppauge, NY (US);
Abstract
A control signal value, such as a duty cycle value for a Pulse Width Modulated (PWM) generator output, for controlling and/or powering a fan may be calculated using an autofan function configured with dynamic hysteresis control (DHC). As part of the DHC, the PWM duty cycle value may be determined by applying a hysteresis component at every point of the autofan function relating the PWM duty cycle to temperature. The PWM duty cycle value may be computed based on two functions, each function relating the PWM duty cycle to temperature, the first function applied when the temperature is increasing, and the second function applied when the temperature is decreasing. When a newly computed PWM duty cycle value falls within a range of duty cycle values defined by the hysteresis value, the current duty cycle of the PWM generator output may remain unchanged, minimizing noise resulting from the fan changing speed.