Intelligent air moving apparatus

Abstract

An intelligent air moving apparatus for cooling an electronics enclosure includes a motor for driving a fan at a variable rotational speed and a microcontroller for controlling the rotational speed of the motor. The microcontroller includes a speed sensor for sensing the rotational speed such that when the sensed rotational speed deviates below a target speed, the microcontroller detects a locked rotor condition.

1 . An intelligent air moving apparatus for cooling an electronics enclosure, the apparatus comprising:
 a motor for driving a fan at a variable rotational speed;   a microcontroller for controlling the rotational speed of the motor, the microcontroller comprising a speed sensor for sensing the rotational speed;   wherein when the sensed rotational speed falls below a target speed by at least a threshold amount, the microcontroller detects a locked rotor condition and initiates a sequence to shut down and restart the motor.   
   
   
       2 . The air moving apparatus of  claim 1 , wherein the speed sensor senses back electromotive force from the motor. 
   
   
       3 . The air moving apparatus of  claim 1 , the microcontroller further comprising a voltage sensor, the motor having one or more phases, wherein when the voltage sensor senses a drop in voltage indicative of removal of power from the motor, the microcontroller simultaneously energizes all motor phases to stop the motor from rotating. 
   
   
       4 . The air moving apparatus of  claim 1 , the microcontroller further comprising a memory for storing data including speed avoidance zones, wherein when the target speed is within one of the speed avoidance zones, the microcontroller controls the motor speed to be slightly outside said speed avoidance zone. 
   
   
       5 . The air moving apparatus of  claim 1 , further comprising an interface for electronically communicating between the microcontroller and an infrastructure controller external to the air moving apparatus, wherein when the interface indicates a loss of communication, the microcontroller maintains the rotational speed at a default speed. 
   
   
       6 . The air moving apparatus of  claim 1 , the microcontroller further comprising memory for storing static data and an interface for electronically communicating between the microcontroller and an infrastructure controller external to the air moving apparatus, wherein the microcontroller communicates the static data to the infrastructure controller via the interface. 
   
   
       7 . The air moving apparatus of  claim 1 , the microcontroller further comprising memory for storing dynamic data and an interface for electronically communicating between the microcontroller and an infrastructure controller external to the air moving apparatus, wherein the microcontroller communicates the dynamic data to the infrastructure controller via the interface. 
   
   
       8 . The air moving apparatus of  claim 1 , further comprising an overcurrent protector for shutting down and restarting the motor upon the detection of a high current condition. 
   
   
       9 . The air moving apparatus of  claim 1 , further comprising an interface having redundant communication channels for electronically communicating between the microcontroller and an infrastructure controller external to the air moving apparatus, the infrastructure controller being adapted to switch between channels when one of the channels fails. 
   
   
       10 . The air moving apparatus of  claim 1 , further comprising at least one light emitting diode in electronic communication with the microcontroller to indicate at least one status condition of the apparatus. 
   
   
       11 . The air moving apparatus of  claim 1 , wherein the microcontroller further provides a failure alert when a locked rotor condition is detected. 
   
   
       12 . The air moving apparatus of  claim 1 , wherein the microcontroller further provides an alert indicating that inspection of the fan is needed after a predetermined number of shut down and restart sequences. 
   
   
       13 . The air moving apparatus of  claim 1 , wherein the microcontroller further measures power to the motor, and wherein the microcontroller provides a pre-failure alert when a deviation is detected from an expected relationship between the motor rotational speed and the motor power. 
   
   
       14 . The air moving apparatus of  claim 1 , further comprising a temperature sensor for measuring motor temperature, wherein the microcontroller provides a pre-failure alert when the motor temperature deviates from an expected normal operating temperature. 
   
   
       15 . The air moving apparatus of  claim 1 , further comprising a temperature sensor for measuring fan air inlet temperature, wherein the microcontroller controls the motor rotational speed based on the fan inlet temperature. 
   
   
       16 . A system for cooling an electronics enclosure, comprising:
 a plurality of fan modules, each fan module comprising:
 a motor for driving a fan at a variable rotational speed; 
 a microcontroller for controlling the rotational speed of the motor; 
 an interface for electronically communicating between the microcontroller and an infrastructure controller external to the fan module, the infrastructure controller providing a target speed to the microcontroller; and 
 a memory for storing data including speed avoidance zones; 
 wherein when the target speed falls within one of the speed avoidance zones, the microcontroller controls the motor speed to be slightly outside said speed avoidance zone. 
   
   
   
       17 . The system of  claim 16 , the microcontroller comprising a speed sensor for detecting the rotational speed, wherein when the rotational speed sensed by the speed sensor falls below a target speed by at least a threshold amount, the microcontroller detects a locked rotor condition and initiates a sequence to shut down and restart the motor. 
   
   
       18 . The system of  claim 16 , the microcontroller comprising a voltage sensor, wherein when the voltage sensor senses a drop in voltage indicative of removal of power from the motor, the microcontroller simultaneously energizes all one or more motor phases to stop the motor from rotating. 
   
   
       19 . The system of  claim 16 , wherein when the interface indicates a loss of communication with the infrastructure controller, the microcontroller maintains the rotational speed at a default speed. 
   
   
       20 . The system of  claim 16 , the fan module further comprising a crystal oscillator to ensure an accurate time base for motor speed measurements. 
   
   
       21 . A method of cooling an electronics enclosure comprising:
 providing at least one fan module comprising a multi-phase motor for driving a fan at a variable rotational speed and a microcontroller for controlling the rotational speed of the motor;   sensing the rotational speed; and   detecting a locked rotor event when the sensed rotational speed falls below a target speed by at least a threshold amount.   
   
   
       22 . The method of  claim 21 , further comprising:
 controlling the rotational speed to be outside one or more speed avoidance zones defined by natural frequencies of the fan module.   
   
   
       23 . The method of  claim 21 , further comprising:
 when more than one fan module is provided, starting the fans sequentially instead of simultaneously to avoid power surges.   
   
   
       24 . The method of  claim 21 , further comprising:
 providing a communications interface adapted to receive a target speed signal; and   maintaining the rotational speed at a default speed when the communications interface detects a loss of the target speed signal.