Current sensing temperature control circuit and methods for maintaining operating temperatures within information handling systems

Abstract

An information handling system including a system fan control is disclosed. The information handling system can include a power trace operable to produce a temperature differential in response to a current change within the reduced trace width region. A thermistor may be provided in close proximity to the reduced trace width region and can be operable to detect the temperature differential provided in response to the current change. A printed circuit board for use in an information handling system and a method of using the information handling system are also disclosed.

1 . An information handling system including a system fan control, the information handling system comprising: 
 a first power trace operable to produce a temperature differential in response to a current change within a first reduced trace width region of the first power trace; and    a first thermistor provided in close proximity to the first reduced trace width region and operable to detect the temperature differential provided in response to the current change.    
   
   
       2 . The system of  claim 1 , further comprising: 
 a fan controller coupled to an output of the first thermistor and responsive to the temperature differential detected by the first thermistor, the fan controller operable to alter a fan speed of a first fan based on the output to maintain an operating temperature of the electronics coupled to the first power trace;    a second thermistor proximally located to a second reduced trace width region along a second power trace and operable to detect a second temperature differential; and    wherein the second thermistor is operable to provide a second input to the fan controller to alter the first fan speed.    
   
   
       3 . The system of  claim 2 , wherein the fan controller is operable to detect the second input and alter an operating speed of a second fan to maintain an operating temperature of electronics coupled to the second power trace.  
   
   
       4 . The system of  claim 1 , further comprising a remote thermistor coupled at a location remote to the first thermistor, the remote thermistor operable to provide an input to the fan controller to alter the fan speed of the first fan based on an ambient temperature.  
   
   
       5 . The system of  claim 4 , wherein the fan controller is operable to receive an input from the first thermistor and an input from the remote thermistor and alter the fan speed of the first fan in response to at least one of the inputs.  
   
   
       6 . The system of  claim 1 , wherein the first thermistor is thermally coupled to the first reduced contact region using a thermal via.  
   
   
       7 . The system of  claim 1 , wherein the first thermistor is coupled to a rear portion of a printed circuit board having the first reduced trace width region.  
   
   
       8 . The system of  claim 1 , further comprising: 
 sensing means for detecting power consumed by the electronics;    controller means for altering the fan speed to maintain an operating temperature of the electronics; and    input means for receiving signals from the thermistor.    
   
   
       9 . A method of maintaining operating temperatures of electronics stored within an information handling system, the method comprising the steps of: 
 detecting a first temperature differential using a first thermistor provided in close proximity to a first power trace including a first reduced trace width region;    receiving an input from the first thermistor; and    altering a fan speed of a first fan to maintain an operating temperature of the electronics in response to the first temperature differential.    
   
   
       10 . The method of  claim 9 , further comprising: 
 detecting a second temperature differential using a second thermistor proximally located to a second power trace having a second reduced trace width region along the second power trace; and    altering the fan speed of the first fan in response to a second temperature differential to maintain an operating temperature of electronics coupled to the second power trace.    
   
   
       11 . The method of  claim 9 , further comprising: 
 detecting a second temperature differential using a second thermistor proximally located to a second power trace having a second reduced trace width region; and    altering the fan speed of the first fan in response to a second temperature differential to maintain an operating temperature of electronics coupled to the second power trace.    
   
   
       12 . The method of  claim 11 , further comprising: 
 receiving a second input at a fan controller from a source other than the first thermistor; and    altering the fan speed of the first fan in response to the second input.    
   
   
       13 . The method of  claim 9 , further comprising: 
 determining a trace width sufficient to provide a temperature differential as an input to a controller to maintain the operating temperature through altering the fan speed of the first fan; and    providing the trace width at the reduced trace width region of the first power trace.    
   
   
       14 . The method of  claim 13 , further comprising: 
 determining a resistive heating to be provided by the reduced trace width region;    determining a thermistor type operable to detect the resistive heating as the first temperature differential and provide the input; and    coupling the thermistor type as the first thermistor proximal to the first reduced trace width region.    
   
   
       15 . A printed circuit board comprising: 
 a power trace of a power circuit operable to power electronics, the power trace including a width and a reduced trace width region; and    a thermistor-coupling region operable to mount a thermistor in close proximity to the reduced trace width region.    
   
   
       16 . The printed circuit board of  claim 15 , wherein the reduced trace width region is reduced by at least twenty-five percent (25%) of the width.  
   
   
       17 . The printed circuit board of  claim 15 , wherein the reduced trace width region is reduced by at least fifty percent (50%) of the width.  
   
   
       18 . The printed circuit board of  claim 15 , wherein the reduced trace width region is located at a distance from a ground plane.  
   
   
       19 . The printed circuit board of  claim 15 , wherein the reduced trace width region is located at a distance from a power plane.  
   
   
       20 . The printed circuit board of  claim 15 , further comprising a thermistor mounted to the thermistor-coupling region and operable to detect resistive heating of the reduced trace width region.