Intelligent cooling fan device and fan rotation speed controlling method thereof

Abstract

A fan cooling device and a method of controlling a fan rotation speed are provided. The fan cooling device includes a thermo sensor, a thermo monitor unit, a processing unit, a driving unit, and a fan. The thermo monitor unit compares the sensed result from the thermo sensor with at least one threshold, and decides whether or not to send an interrupt event according to the compared result. The processing unit executes an interrupt service according to the interrupt event, and then sets and outputs a value of the fan rotation speed. The driving unit drives the fan and controls the rotation speed of the fan according to the value of the fan rotation speed. The fan sends out a wind flow to reduce the internal temperature of a computer system or a CPU.

1 . A fan cooling device, comprising:
 a thermo sensor, for sensing an operating temperature and outputting a sensed result;   a fan, for providing a wind flow to reduce the operating temperature;   a thermo monitor unit, coupled to the thermo sensor, for comparing the sensed result with at least one threshold, and deciding whether or not to send an interrupt event according to a compared result;   a processing unit, coupled to the thermo monitor unit, for executing an interrupt service according to the interrupt event to set and output a value of a fan rotation speed; and   a driving unit, coupled between the processing unit and the fan, for driving the fan and controlling a rotation speed of the fan according to the value of the fan rotation speed.   
   
   
       2 . The fan cooling device according to  claim 1 , wherein the thermo monitor unit comprises a plurality of thresholds for defining a plurality of temperature control ranges. 
   
   
       3 . The fan cooling device according to  claim 1 , wherein the interrupt service comprises a rotation speed table, and wherein once the interrupt event occurs, the interrupt service reads the sensed result from the thermo sensor, looks up the rotation speed table to obtain a corresponding value of the fan rotation speed, and outputs the value of the fan rotation speed to the driving unit. 
   
   
       4 . The fan cooling device according to  claim 1 , wherein the operating temperature is an internal temperature of a computer system. 
   
   
       5 . The fan cooling device according to  claim 4 , wherein the operating temperature is a temperature of a central processing unit (CPU). 
   
   
       6 . A method of controlling a fan rotation speed, comprising:
 sensing an operating temperature to obtain a sensed result;   comparing the sensed result with at least one threshold to obtain a compared result;   deciding whether or not to send an interrupt event according to a compared result;   executing an interrupt service according to the interrupt event to set a value of a fan rotation speed; and   driving a fan and controlling a rotation speed of the fan according to the value of the fan rotation speed to provide a wind flow to reduce the operating temperature.   
   
   
       7 . The method of controlling a fan rotation speed according to  claim 6 , further comprising:
 setting a plurality of thresholds to define a plurality of temperature control ranges, wherein when the sensed result indicates that the operating temperature falls within one of the temperature control ranges, the interrupt service sets a corresponding value of the fan rotation speed.   
   
   
       8 . The method of controlling a fan rotation speed according to  claim 6 , further comprising providing a rotation speed table, wherein once the interrupt event occurs, the interrupt service looks up the rotation speed table according to the sensed result, so as to obtain the corresponding value of the fan rotation speed. 
   
   
       9 . The method of controlling a fan rotation speed according to  claim 6 , wherein the operating temperature is an internal temperature of a computer system. 
   
   
       10 . The method of controlling a fan rotation speed according to  claim 9 , wherein the operating temperature is a temperature of a CPU.