Patent Publication Number: US-2013235523-A1

Title: Server

Description:
BACKGROUND  
     1. Technical Field 
     The present disclosure relates to a server. 
     2. Description of Related Art 
     In a cabinet, a plurality of fans is used for cooling servers. A power supply unit supplies power for the fans in the cabinet. If there are more than one server in the cabinet, the fans are powered on without reference to working status of the servers. For example, if only one server is operating in the cabinet, all of the fans are powered on through the power supply unit. This is a waste of energy. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
       Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawing are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an isometric view of an exemplary embodiment of a server. 
         FIG. 2  is a block diagram of the server of  FIG. 1 , wherein the server includes first and second subsystems and a backplane. 
         FIG. 3  is a circuit diagram of the first subsystem and the backplane of  FIG. 1 . 
         FIG. 4  is a circuit diagram of the second subsystem and the backplane of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION  
     The disclosure, including the accompanying drawings, is illustrated by way of examples and not by way of limitation. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. 
     Referring to  FIGS. 1-4 , an exemplary embodiment of a server  100  is shown. The server  100  includes a chassis  10 , a first subsystem  20 , a second subsystem  30 , and a backplane  40 . 
     First and second groups of connectors are set on the backplane  40 . In the embodiment, the first group of connectors includes a first connector  41  and a second connector  42 . The second group of connectors includes a third connector  43  and a fourth connector  44 . 
     The first subsystem  20  has same structure and function with the second subsystem  30 . The first subsystem  20  is described as follows. 
     The first subsystem  20  includes a first group of fans, a first group of motherboards, and a first fan control circuit  25 . In the embodiment, the first group of fans includes a first fan  21  and a second fan  22 . The first group of motherboards includes a first motherboard  23  and a second motherboard  24 . 
     Referring to  FIG. 3 , the first motherboard  23  and the second motherboard  24  are mounted in the chassis  10  of the server  100 , with the second motherboard  24  located below the first motherboard  23 . A first fan controller  232 , a first voltage pin  234 , and a first ground pin  236  are set on the first motherboard  23 . A second fan controller  242 , a second voltage pin  244 , and a second ground pin  246  are set on the second motherboard  24 . 
     The first fan  21  and the second fan  22  are mounted in the chassis  10 , respectively behind the first motherboard  23  and the second motherboard  24 . The first fan  21  includes a first ground pin  211 , a first control pin  212 , a first speed pin  213 , and a first voltage pin  214 . The second fan  22  includes a second ground pin  221 , a second control pin  222 , a second speed pin  223 , and a second voltage pin  224 . 
     The first fan control circuit  25  includes a first comparator  252 , a first diode D 1 , and a second diode D 2 . 
     The first ground pin  211  of the first fan  21  is connected to the first ground pin  236  of the first motherboard  23  through the first connector  41  of the backplane  40 . The first speed pin  213  of the first fan  21  is connected to the first fan controller  232  of the first motherboard  23  through the first connector  41 , for outputting a first speed signal to the first fan controller  232 . The first speed pin  213  of the first fan  21  is connected to the second fan controller  242  on the second motherboard  24  through the second connector  42 , for outputting the first speed signal to the second fan controller  242 . The first voltage pin  214  of the first fan  21  is connected to a first terminal of a first fuse L 1 . A second terminal of the first fuse L 1  is connected to cathodes of the first and second diodes D 1  and D 2 . An anode of the first diode D 1  is connected to the first voltage pin  234  on the first motherboard  23  through the first connector  41  on the backplane  40 . The first control pin  212  of the first fan  21  is connected to an output pin of the first comparator  252 . 
     The second ground pin  221  of the second fan  22  is connected to the second ground pin  246  of the second motherboard  24  through the second connector  42  on the backplane  40 . The second speed pin  223  of the second fan  22  is connected to the second fan controller  242  on the second motherboard  24  through the second connector  42  on the backplane  40 , for outputting a second speed signal to the second fan controller  242 . The second speed pin  223  of the second fan  22  is further connected to the first fan controller  232  on the first motherboard  23  through the first connector  41  on the backplane  40 , for outputting the second speed signal to the first fan controller  232 . The second voltage pin  224  of the second fan  22  is connected to a first terminal of a second fuse L 2 . A second terminal of the second fuse L 2  is connected to cathodes of the first and second diodes D 1  and D 2 . An anode of the second diode D 2  is connected to the second voltage pin  244  on the second motherboard  24  through the second connector  42  on the backplane  40 . The second control pin  222  of the second fan  22  is connected to the output pin of the first comparator  252 . 
     A first input pin of the first comparator  252  is connected to the first fan controller  232  on the first motherboard  23  through the first connector  41  on the backplane  40 , for receiving a first pulse-width modulation (PWM) signal. A second input pin of the first comparator  252  is connected to the second fan controller  242  on the second motherboard  24  through the second connector  42  on the backplane  40 , for receiving a second PWM signal. The first comparator  252  compares the first PWM signal with the second PWM signal, and outputs one of the PWM signals with a greater duty cycle to the first control pin  212  of the first fan  21  and the second control pin  222  of the second fan  22 , for controlling the first fan  21  and the second fan  22  to operate at greater speeds. 
     When the first motherboard  23  and the second motherboard  24  are operating, the first voltage pin  234  of the first motherboard  23  outputs a voltage to the anode of the first diode D 1 , and the second voltage pin  244  of the second motherboard  24  outputs a voltage to the anode of the second diode D 2 . The first diode D 1  and the second diode D 2  are turned on. The first fan  21  and the second fan  22  are powered on. 
     When one of the first motherboard  23  or the second motherboard  24  is not operating, such as the first motherboard  23  is not operating but the second motherboard  234  is operating, the first voltage pin  234  of the first motherboard  23  does not output the voltage, and the second voltage pin  244  of the second motherboard  24  outputs the voltage. In this condition, the first diode D 1  is turned off, and the second diode D 2  is turned on. The second voltage pin  244  of the second motherboard  24  outputs the voltage to the first fan  12  and the second fan  22 . The first fan  21  and the second fan  22  are powered on. 
     When both the first motherboard  23  and the second motherboard  24  are not operating, the first voltage pin  234  of the first motherboard  23  and the second voltage pin  244  of the second motherboard  24  do not output the voltage. In this condition, the first diode D 1  and the second diode D 2  are turned off. The first fan  21  and the second fan  22  are not powered on. 
     Referring to  FIG. 4 , the second subsystem  30  has the same structure as the first subsystem  20 . When third and fourth motherboards  33  and  34  of the second subsystem  30  are operating, a third voltage pin  334  of the third motherboard  33  outputs the voltage to an anode of a third diode D 3 , and a fourth voltage pin  344  of the fourth motherboard  34  outputs the voltage to an anode of a fourth diode D 4 . The third and fourth diodes D 3  and D 4  are turned on. The third fan  31  and the fourth fan  32  are powered on. 
     When one of the third motherboard  33  and the fourth motherboard  34  are not operating, such as the third motherboard  33  is not operating but the fourth motherboard  34  is operating, the third voltage pin  334  of the third motherboard  33  does not output the voltage, and the fourth voltage pin  344  of the fourth motherboard  34  outputs the voltage. In this condition, the third diode D 3  is turned off, and the fourth diode D 4  is turned on. The fourth voltage pin  344  of the fourth motherboard  34  outputs the voltage to the third fan  31  and the fourth fan  32 . The third fan  31  and the fourth fan  32  are powered on. 
     When both of the third motherboard  33  and the fourth motherboard  34  are not operating, the third voltage pin  334  of the third motherboard  33  and the fourth voltage pin  344  of the fourth motherboard  34  do not output the voltage. In this condition, the third diode D 3  and the fourth diode D 4  are turned off. The third fan  31  and the fourth fan  32  are not powered on. 
     As a result, when one of the first motherboard  23  or the second motherboard  24  is operating, the first fan  21  and the second fan  22  are operating. When both the third and fourth motherboards  33  and  34  are not operating, the third and fourth fans  31  and  32  are powered off. In other words, when one of the first and second groups of motherboards is not operating, the corresponding group of fans are powered off. 
     In the embodiment, when an inrush current or a spike voltage of the fans occurs, the first and second fuses L 1  and L 2  cut off to protect the server  100 . 
     The foregoing description of the exemplary embodiments of the disclosure has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in the light of everything above. The embodiments were chosen and described in order to explain the principles of the disclosure and their practical application so as to enable others of ordinary skill in the art to utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those of ordinary skills in the art to which the present disclosure pertains without departing from its spirit and scope. Accordingly, the scope of the present disclosure is defined by the appended claims rather than the foregoing description and the exemplary embodiments described therein.