Pulse width modulation fan

Abstract

An apparatus can include a fan including a control pin. The fan may receive a pulse width modulated (PWM) signal at the control pin. The fan may further control a speed of the fan based on a duty cycle of the PWM signal when the PWM signal is in a first range and, responsive to the duty cycle of the PWM signal being in a second range, transmit information corresponding to the fan to an external controller.

What is claimed: 
     
         1 . An apparatus, comprising:
 a fan including a control pin, the fan to:
 receive a pulse width modulated (PWM) signal at the control pin; 
 control a speed of the fan based on a duty cycle of the PWM signal when the PWM signal is in a first range; and 
 responsive to the duty cycle of the PWM signal being in a second range, transmit information corresponding to the fan to an external controller. 
   
     
     
         2 . The apparatus of  claim 1 , wherein the PWM signal being in the second range include the PWM signal being in a range that spans about 10% of a total PWM signal range receivable by the control pin. 
     
     
         3 . The apparatus of  claim 1 , wherein the information corresponding to the fan includes static data, telemetry data, or combinations thereof. 
     
     
         4 . The apparatus of  claim 1 , wherein the fan is to operate at a same speed when the PWM signal is in the first range and when the PWM signal is in the second range. 
     
     
         5 . The apparatus of  claim 4 , wherein the fan further comprises control circuitry to lock the speed of the fan responsive to the duty cycle of the PWM signal being in the second. 
     
     
         6 . The apparatus of  claim 1 , wherein the fan further comprises a sensor to detect a change in an environment of the fan. 
     
     
         7 . The apparatus of  claim 1 , wherein the fan is to transmit information corresponding to the fan via a fault signal pin of the fan. 
     
     
         8 . An apparatus, comprising:
 a fan control component including a processing resource and operable to:
 control operation of a fan based, at least in part, on a duty cycle of a pulse width modulated (PWM) signal when the duty cycle of the PWM signal is in a first range; and 
 request information corresponding to the fan based, at least in part, on the duty cycle of the PWM signal being in a second range. 
   
     
     
         9 . The apparatus of  claim 8 , wherein the fan control component is to cause the information corresponding to the fan to be processed to determine statistical information, analytical information, or combinations thereof, associated with the fan. 
     
     
         10 . The apparatus of  claim 8 , wherein the information corresponding to the fan includes static data, telemetry data, or combinations thereof. 
     
     
         11 . The apparatus of  claim 8 , wherein the duty cycle of the PWM signal being in the second range includes the duty cycle of the PWM signal spanning about 10% of a full duty cycle. 
     
     
         12 . The apparatus of  claim 8 , wherein the duty cycle being in the second range includes the duty cycle being within an upper range of a total pulse width modulation range receivable by the particular signal pin. 
     
     
         13 . The apparatus of  claim 8 , wherein the fan control component is to request information from the fan to be transmitted from a fault signal pin of the fan. 
     
     
         14 . The apparatus of  claim 8 , wherein the fan control component is to cause a diagnostic operation to be performed on the fan based, at least in part, on the received information corresponding to the fan. 
     
     
         15 . A non-transitory machine-readable medium storing instructions executable by a processing resource to cause a computing system to:
 cause a pulse width modulated (PWM) signal corresponding to a first duty cycle range to be asserted on a control pin of a fan to control a speed of the fan;   cause a PWM signal corresponding to a second duty cycle range to be asserted on the control pin of the fan to request information corresponding to the fan to be transferred to a controller external to the fan.   
     
     
         16 . The non-transitory machine-readable medium of  claim 15 , wherein the instructions are further executable to cause the computing system to cause the PWM signal corresponding to the second duty cycle to span about 10% of a full duty cycle. 
     
     
         17 . The non-transitory machine-readable medium of  claim 15 , wherein the instructions are further executable to cause the computing system to process the information requested from the fan to determine static data, telemetry data, or combinations thereof, corresponding to the fan. 
     
     
         18 . The non-transitory machine-readable medium of  claim 15 , wherein the instructions are further executable to cause the computing system to cause the information corresponding to the fan to be displayed via a graphical user interface. 
     
     
         19 . The non-transitory machine-readable medium of  claim 15 , wherein the instructions are further executable to cause the computing system to perform a diagnostic operation on the fan based, at least in part, on the received information corresponding to the fan. 
     
     
         20 . The non-transitory machine-readable medium of  claim 15 , wherein the instructions are further executable to cause the computing system to cause the fan to operate at a same speed that is was operating at immediately prior to the PWM signal having the second duty cycle range being asserted on the control pin of the fan.