Abstract:
A female connector for supplying electric power from a power supply to an electric device includes two power supply terminals to supply the electric power, two relays connected to the two power supply terminals, respectively, to control supply of the electric power, and two control electrodes configured to control opening and, closing of the two relays, wherein the two relays are driven by the power supply, and the two control electrodes are electrically coupled to each other through a control terminal of a male connector upon mating between the female connector and the male connector, the electrical coupling of the two control electrodes causing the two relays to be closed to supply the electric power to the two power supply terminals.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The disclosures herein generally relate to a connector and power supply unit used for the purpose of supplying electric power. 
     2. Description of the Related Art 
     Electric equipment generally receives electric power from a power supply to operate. For the purpose of supplying electric power, connectors are typically used to supply electric power from the power supply to electric equipment. Such connectors include a male-type connector having one or more male pins and a female-type connector having one or more female sockets, which mate with each other to establish electrical connection. This configuration is disclosed in Patent Documents 1 and 2. 
     In recent years, the supply of direct-current high-voltage electric power for local-area electric power transmission has been under study as a measure against global warming. With such a power supply arrangement, power loss is small at the time of voltage conversion and electric power transmission, and, also, there is no need to use thick cables. Especially for information devices such as servers, such a power supply arrangement is believed to be desirable due to their large consumption of electric power. 
     Caution should be taken for the electric power that is supplied to electric equipment because direct contact by a human body is hazardous. In particular, a direct-current electric power has no frequency dependency, which may require greater caution. 
     Manual work is performed for the installment and maintenance of equipment. When direct-current electric power is used for information devices such as servers, thus, connectors used at the point of electrical connection may need to have a special design that is different from that of normal connectors used for commercial power supply. 
     Further, a power supply unit having a plurality of connectors is typically used to supply electric power to loads, e.g., information devices such as servers. 
     [Patent Document 1] Japanese Patent Application Publication No. 5-82208 
     [Patent Document 2] Japanese Patent Application Publication No. 2003-31301 
     SUMMARY OF THE INVENTION 
     It is a general object of the present invention to provide a connector and a power supply unit that substantially eliminate one or more problems caused by the limitations and disadvantages of the related art. Specifically, it may be desirable to provide a connector and power supply unit that can safely supply electric power. 
     According to an embodiment, a female connector for supplying electric power from a power supply to an electric device includes two power supply terminals to supply the electric power, two relays connected to the two power supply terminals, respectively, to control supply of the electric power, and two control electrodes configured to control opening and closing of the two relays, wherein the two relays are driven by the power supply, and the two control electrodes are electrically coupled to each other through a control terminal of a male connector upon mating between the female connector and the male connector, the electrical coupling of the two control electrodes causing the two relays to be closed to supply the electric power to the two power supply terminals. 
     According to an embodiment, a power supply unit comprising a plurality of connectors, at least one of which is the female connector as set forth above. 
     A pair of connectors includes a male connector including a control pin and power pins to receive electric power, and further includes a female connector. The female connector includes two power supply sockets configured to mate with the power pins to supply the electric power to the power pins, two relays connected to the two power supply sockets, respectively, to control supply of the electric power, a control socket configured to mate with the control pin, two control electrodes situated in the control socket to control opening and closing of the two relays, wherein the two control electrodes are electrically coupled to each other through the control pin upon mating between the female connector and the male connector, the electrical coupling of the two control electrodes causing the two relays to be closed to supply the electric power to the two power supply sockets. 
     According to at least one embodiment, a connector and power supply unit that can safely supply electric power are provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a drawing illustrating the configuration of a connector according to an embodiment; 
         FIGS. 2A and 2B  are perspective views of the outer appearances of connectors according to the embodiment; 
         FIGS. 3A through 3D  are drawings illustrating the configuration of the female connector according to the embodiment; 
         FIG. 4  is a drawing illustrating the configuration of a power supply system employing the connectors of the embodiment; and 
         FIG. 5  is a perspective view of a PDU employing the connectors of the embodiment. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following, embodiments of the present invention will be described with reference to the accompanying drawings. 
     [Outline of Connector] 
     In the following, a connector according to an embodiment will be described.  FIG. 1  is a drawing illustrating an outline of the configuration of a female connector according to the present embodiment. 
     A female connector  20  according to the present embodiment is coupled to a direct-current power supply  50  for supplying electric power. The female connector  20  includes power-supply jack terminals  21  and  22  for supplying electric power, a control jack terminal  23 , and a ground jack terminal  24  connected to the earth. Electrodes  37  and  38  are provided inside the control jack terminal  23 . 
     A male connector  10  that is to be connected to the female connector  20  according to the present embodiment is coupled to an information device  40  such as a server through a power supply cable  15 . The male connector  10  includes power supply plug terminals  11  and  12  to mate with the power-supply jack terminals  21  and  22 , a control plug terminal  13  to mate with the control jack terminal  23 , and a ground plug  14  to mate with the ground jack terminal  24 . 
     Two relays  31  and  32  are provided in the female connector  20 . The relay  31  includes a coil  33  and a relay contact  34  that is closed to provide electrical connection in response to an electrical current running through the coil  33 . The relay contact  34  is placed in an open state to provide no electrical connection when no electric current flows through the coil  33 . The relay  32  includes a coil  35  and a relay contact  36  that is closed to provide electrical connection in response to an electrical current running through the coil  35 . The relay contact  36  is placed in an open state to provide no electrical connection when no electric current flows through the coil  35 . 
     One end of the relay contact  34  is connected to a positive output of the direct-current power supply  50 , and the other end thereof is connected to the power-supply jack terminal  21 . One end of the relay contact  36  is connected to a negative output of the direct-current power supply  50 , and the other end thereof is connected to the power-supply jack terminal  22 . 
     In order to drive the relays  31  and  32 , the female connector  20  receives the direct-current power supply  50  that is the same as the power supply for supplying electric power through the connectors. To be specific, one end of the coil  33  of the relay  31  is connected to one end of the coil  35  of the relay  32 . With this arrangement, the coil  33  of the relay  31  and the coil  35  of the relay  32  are connected in series (i.e., series-connected). The other end of the coil  33  is connected to one end of the direct-current power supply  50 . The other end of the coil  35  and the other end of the direct-current power supply  50  are connected to the two electrodes  38  and  37 , respectively, which are situated inside the control jack terminal  23 . 
     In this manner, the direct-current power supply  50  is used as the power supply to drive the relays  31  and  32 . This arrangement eliminates the need to provide a dedicated power supply for driving the relays  31  and  32 , thereby simplifying the configuration. This arrangement also reduces the costs of the connector and a PDU, which will be described later. 
     The two electrodes  37  and  38  are electrically coupled to each other through the control plug terminal  13  inside the control jack terminal  23  when the male connector  10  and the female connector  20  mate with each other. To this end, the control plug terminal  13  is made of an electrical conductor. The length of the control plug terminal  13  may be set to such a length that the two electrodes  37  and  38  are coupled to each other through the control plug terminal  13  only after the power supply plug terminals  11  and  12  fully mate with the power-supply jack terminals  21  and  22 , respectively. Namely, the two electrodes  37  and  38  are coupled to each other through the control plug terminal  13  only after the entire lengths of the power supply plug terminals  11  and  12  are inserted into the power-supply jack terminals  21  and  22 , respectively. To this end, the length of the control plug terminal  13  may be set shorter than the length of the power supply plug terminals  11  and  12 . 
     In this manner, the electrodes  37  and  38  are electrically coupled to each other through the control plug terminal  13 . As a result, an electric current from the direct-current power supply  50  flows through the coils  33  and  35  of the respective relays  31  and  32  to close the relay contacts  34  and  36 , thereby supplying electric power to the power-supply jack terminals  21  and  22  of the female connector  20 . Consequently, electric power is supplied to the information device  40  such as a server through the power supply plug terminals  11  and  12  of the male connector  10 . 
     In the female connector  20  of the present embodiment, the relay contacts  34  and  36  of the respective relays  31  and  32  are electrically connected to the power-supply jack terminals  21  and  22 , respectively. The reason why the relay contact is provided for both of the power-supply jack terminals  21  and  22  is that the danger to human body through direct contact is extremely high in the case of a direct current of 200 V or higher. The above-noted arrangement controls the supply of electric power at both of the power-supply jack terminals  21  and  22 , thereby further improving safety. 
     [Configuration of Connector] 
     In the following, a description will be given of the configuration of the connectors according to the present embodiment and the method of connection by referring to  FIGS. 2A and 2B  and  FIGS. 3A through 3D .  FIG. 2A  is a diagrammatic perspective view of the outer appearance of the male connector  10 .  FIG. 2B  is a diagrammatic perspective view of the outer appearance of a female connector socket  20 A according to the present embodiment. The female connector socket  20 A is a socket portion of the female connector  20  as illustrated in  FIG. 1 . 
       FIG. 3A  is a top view of the female connector socket  20 A according to the present embodiment.  FIG. 3B  is a longitudinal side view of the female connector socket  20 A according to the present embodiment.  FIG. 3C  is a rear view of the female connector socket  20 A according to the present embodiment.  FIG. 3D  is a transverse side view of the female connector socket  20 A according to the present embodiment. 
     As illustrated in  FIG. 2A , the outer shape of the male connector  10  has a width W 1  of 30 mm, a length D 1  of 30 mm, and a height H 1  of 16 mm. The power supply cable  15  to supply a direct-current voltage of 400 V is connected to the male connector  10 . The other side of the male connector  10  has the power supply plug terminals  11  and  12 , the control plug terminal  13 , and the ground plug terminal  14 , which are made of metal. The power supply plug terminals  11  and  12  each have a length A of 17 mm. The ground plug terminal  14  has a length B of 19 mm. The control plug terminal  13  has a length C of 14.5 mm. 
     As illustrated in  FIG. 2B  and  FIGS. 3A through 3D , the female connector socket  20 A of the present embodiment has a structure into which a portion of the male connector  10  is fit. The female connector socket  20 A has the power-supply jack terminals  21  and  22  to be connected to the power supply plug terminals  11  and  12 , respectively, and also has the ground jack terminal  24  to be connected to the ground plug terminal  14 . Further, the female connector socket  20 A has the control jack terminal  23  to be connected with the control plug terminal  13 , with the electrodes  37  and  38  situated therein. 
     The female connector socket  20 A also has terminals on its rear side, which are for connection to a PDU or the like. Specifically, a power supply terminal  21 A, a power supply terminal  22 A, a ground terminal  24 A, and control terminals  23 A and  23 B are provided. The power supply terminal  21 A is for connecting the power-supply jack terminal  21  to the relay contact  34  of the relay  31 . The power supply terminal  22 A is for connecting the power-supply jack terminal  22  to the relay contact  36  of the relay  32 . The ground terminal  24 A is connected to the ground jack terminal  24 . The control terminals  23 A and  23 B are connected to the respective electrodes  37  and  38  of the control jack terminal  23 . 
     As illustrated in  FIGS. 3A and 3B , the female connector socket  20 A has a width W 2  of 56 mm, a length D 2  of 40 mm, and a height H 2  of 40.5 mm. In the present embodiment, the relays  31  and  32  are situated outside the female connector socket  20 A. Alternatively, the relays  31  and  32  may be situated inside the female connector socket  20 A. 
     The electrodes  37  and  38  of the female connector socket  20 A do not come in contact with each other when the female connector socket  20 A is not connected to the male connector  10 . Upon insertion of the control plug terminal  13 , the electrodes  37  and  38  come in contact with the control plug terminal  13 , so that the electrodes  37  and  38  are electrically coupled to each other through the control plug terminal  13  to allow the passage of electric current. 
     The length of the control plug terminal  13  may be shorter than the length of the power supply plug terminals  11  and  12 . This prevents a high DC voltage of 400 V from being applied to the power-supply jack terminals  21  and  22  before the power supply plug terminals  11  and  12  fully mate with the power-supply jack terminals  21  and  22 , respectively. If the high DC voltage of 400 V is applied to the power-supply jack terminals  21  and  22  of the female connector  20  before the male connector  10  is fully inserted into the female connector  20 , there is an obvious danger to personnel. The personnel may inadvertently touch the power-supply jack terminals  21  and  22 , or may accidentally come in contact with the power-supply jack terminals  21  and  22  through a screw driver, a metal shard, a fragmented wire, or the like. 
     [Power Supply System] 
     In the following, a description will be given of the configuration of a power supply system employing the connectors of the present embodiment. 
       FIG. 4  is a drawing illustrating the configuration of a power supply system employing the connectors of the present embodiment. 
     The power supply system supplies an AC electric power from a commercial power supply  70  to the direct-current power supply  50 . An AC-to-DC converter  51  of the direct-current power supply  50  converts the AC electric power into a direct-current voltage of 400 V. The direct-current electric power can be stored in a battery or the like. A battery  52  is thus provided as a backup power supply. This makes it possible to cope with a blackout or the like. The female connector  20  of the present embodiment is connected to the direct-current power supply  50  through a power supply cable. The electric power of the 400-V direct-current voltage of the direct-current power supply  50  is supplied through the female connector  20 . A direct-current power generator  53  such as a PV (photovoltaic cell) or FC (fuel cell) that does not require power supply from the commercial power supply  70  is provided in the direct-current power supply  50 . Voltage conversion may be performed according to need. 
     The male connector  10  is connected through the power supply cable  15  to the information device such as a server serving as a load. The female connector  20  and the male connector  10  are electrically coupled to each other. With this arrangement, the electric power of the direct-current power supply  50  is supplied to the information device  40  such as a server. 
     Further, a DC-to-DC converter  41  is provided in the information device  40  such as a server, and converts the 400-V direct-current voltage into a lower DC voltage that is usable by electrical components such as a CPU  42 . 
     Such a power supply system has an advantage in that power loss is small because an AC-to-DC conversion from the commercial power supply  70  is performed only once. Further, there is not much need to pay attention to the thickness of conducting wires or the like in the case of a high direct-current voltage of 400 V. Moreover, a direct-current electric power is storable in the battery  52 , which makes it easier to cope with the stoppage of the commercial power supply  70  such as a blackout. 
     In the following, a description will be given of a PDU (i.e., power distribution unit) using the connectors of the present embodiment by referring to  FIG. 5 . 
     The 400-V direct-current voltage supplied from the direct-current power supply  50  illustrated in  FIG. 4  is applied to a distribution board  70 , which distributes electric power to each PDU  30 . Each PDU  30  has a plurality of female connectors  20  of the present embodiment, and supplies the electric power of the 400-V direct-current voltage through each of the female connectors  20 . A server rack  45  accommodates a plurality of information devices  40  such as servers. The male connector  10  for receiving power supply is connected to each of the information devices  40  such as servers through the power supply cable  15 . A male connector  10  is electrically connected to a female connector  20  situated in the PDU  30  to receive the electric power of the 400-V direct-current voltage. 
     Further, the present invention is not limited to these embodiments, but various variations and modifications may be made without departing from the scope of the present invention. 
     The present application is based on Japanese patent application No. 2008-288800 filed on Nov. 11, 2008, with the Japanese Patent Office, the entire contents of which are hereby incorporated by reference.