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:
Nov. 24, 2009
Filed:
Sep. 29, 2005
Timothy Dorr, North Attleboro, MA (US);
Timothy Dorr, North Attleboro, MA (US);
EMC Corporation, Hopkinton, MA (US);
Abstract
A speed control system is provided for controlling temperature within a chassis. The chassis includes therein a temperature sensing device for producing a temperature signal representative of temperature within the chassis, a fan, and a fan speed controller. The fan speed controller produces a nominal fan speed control signal comprising a train of pulses, successive pulses having a duty cycle related to the temperature signal produced by the temperature sensing device, such time durations decreasing with increasing temperature. The speed control system includes a decoupling circuit responsive to the nominal fan speed control signal for, in response to relatively a low duty cycle, coupling the nominal fan control signal to an output of the decoupling circuit, and, in response a relatively high duty cycle, producing a preset fan speed signal at the output of the decoupling circuit. The fan has a speed in accordance with the signal at the output of the decoupling circuit.