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US 7,890,219 B2Granted
Cooling fan with speed maintained during wait period despite decreasing temperature
AssigneeHewlett-Packard Development Company, L.P.
InventorGeorge Tuma
Life of this patent
Estimating the term…
Abstract
A controller controls fan speed as a function of temperature indications. The controller maintains a constant fan speed despite indications of decreasing temperature at least until a preset wait period has expired since the last fan-speed change.
Claims20
A system comprising:
- a fan having a variable fan speed;
- a thermal sensor for providing temperature indications;
- a timer for indicating whether a preset wait period since a last fan-speed change is active or has expired;
- a controller communicatively coupled to said sensor for controlling said fan speed at least in part in response to changes in said temperature indications, said controller, in response to said temperature indications indicating said fan speed can be reduced, determining whether to maintain or decrease said fan speed based on whether said wait period is active or has expired.
1 more element
A method comprising:
- monitoring a temperature level and a direction of temperature change to provide temperature indications;
- determining a required fan speed for a fan at least in part as a function of said temperature indications;
- comparing said required fan speed with a current fan speed of said fan;
- if said required fan speed equals said current fan speed, maintaining said current fan speed;
- if said required fan speed is greater than said current fan speed, increasing said fan speed to said required fan speed;
- if said required fan speed is less than said current fan speed, determining whether to maintain or decrease said fan speed based on whether a wait period since a last fan-speed change is active or has expired;
- and
- if said wait period is active, maintaining said current fan speed, and
- if said wait period has expired, decreasing said fan speed.
6 more elements
Dependencies are inferred from the claim text.