Abstract:
An electrical connector includes a housing and an arrangement. The arrangement includes microelectromechanical systems (MEMS) or a piezoelectric element or a combination thereof, configured to displace a temperature controlling medium. The electrical connector also includes at least one opening in the housing for transporting the temperature controlling medium displaced by the arrangement through the opening.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority based on European Patent Application No. 11153344.4 filed Feb. 4, 2011 and U.S. Provisional patent application No. 61/439,945 filed Feb. 7, 2011, the disclosures of which are incorporated by reference herein in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to devices for protection against heating, e.g. during battery charging of an electrical device such as a mobile telephone, e.g. in order to improve the charging degree of the terminal. 
       BACKGROUND 
       [0003]    It is known that mobile devices, such as mobile telephones need batteries or accumulators to store electrical energy to keep them in operation-ready status, and that these are therefore implemented directly in the device. It is also known that these batteries are being designed with progressively small dimensions, in order to fit into the mobile device, whose dimensions are also becoming progressively smaller. 
         [0004]    Heat is one problem when using the devices, especially when charging the battery. The intensive use usually drains the battery faster and users wish to charge the battery fast. For mobile devices charging times down to few minutes are desired. The generated heat usually heats the entire device to a level that is not acceptable by the users. 
         [0005]    Fast charging means high currents. Even small resistive losses in the charging path may create high power loss. The resistive loss may be found in the battery and/or charging regulator. However, some types of batteries, such as Li-poly or Li-ion batteries actually do not generate any substantial amount of heat but heat is generated in the charging circuitry. 
         [0006]    To ensure that the usability period nevertheless remains relatively long, however, high energy densities are needed therefore. In many cases, however, this elevated energy density causes the danger of overheating of the batteries if adequate ventilation thereof is not assured. This situation is analogously comparable with the elevated operating temperature that can develop, for example, in the internal combustion engine of an overloaded motor vehicle that is not adequately cooled. For example, the occurrence of battery temperatures of up to 600° C. has already been detected in tests with mobile telephones. This aspect represents a considerable safety risk for mobile telephone users, however, since overheated mobile telephones can catch fire or even explode. Users have already been injured on many occasions due to incidents in which mobile telephones have overheated or even exploded. In particular, not only have body burns requiring medical treatment occurred, but also property damage has been suffered. 
         [0007]    Recently very small fans or pumps have been developed using MEMS (microelectromechanical systems) technology. The MEMS fans may use piezoelectric material as actuator. With sizes, e.g. up to 1 mm thick and 6-12 mm in diameter, MEMS fans and/or pumps give a great advantage. 
         [0008]    MEMS fans/pumps have usually been used for integrated circuit heat dissipation attached directly on or inside, for example, microprocessors or other heat generating components. 
       SUMMARY 
       [0009]    One object of the invention is to improve the protection against overheated operating temperatures of electrical devices. Another object of the invention is to improve airflow and thus decrease heating by removing heat specially when charging a battery of an electrical device. 
         [0010]    For these reasons, an electrical connector comprising a housing is provided. The connector comprises an arrangement configured to displace a temperature controlling medium and at least one opening in said housing for transporting said temperature controlling medium displaced by said arrangement through said opening. The arrangement is microelectromechanical systems, MEMS, arrangement, a piezoelectric arrangement or a combination thereof. The arrangement may be one or several of a fan or a pump. The connector may further comprise at least one opening functioning as intake for said medium. 
         [0011]    According to one embodiment, the connector may be connected to a charger. The connector may comprise a power feed from said charger to said arrangement. The connector may be configured to start said arrangement when a charging is started. 
         [0012]    The connector may comprise an airtight sealing. The intakes and openings may be provided with non return valves or MEMS valves. 
         [0013]    The invention also relates to an electrical device comprising a housing and a connector for connection to a connector is featured earlier, and further comprise intakes corresponding to said openings. The electrical device may further comprise at least one outlet. The intakes and outlets are provided with non return valves or MEMS valves. The electrical device may comprise a temperature sensor for actuating said arrangement. The electrical device may be one of a radiotelephone, a camera, a sound recorder, a global positioning system (GPS) receiver; a personal communications system (PCS) terminal, a cellular radiotelephone, a personal digital assistant (FDA) or a laptop. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The foregoing will be apparent from the following more particular description of the example embodiments, as illustrated in the accompanying drawings in which the like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the example embodiments. 
           [0015]      FIG. 1  illustrates a perspective view of connector according to the invention, 
           [0016]      FIG. 2  illustrates schematically a view from above and through the connector of  FIG. 1   
           [0017]      FIG. 3  illustrates, in a schematic way, a sectional side view of a second embodiment of a connector according to the present invention, 
           [0018]      FIG. 4  illustrates, in a schematic way and sectional side view, the connector according to  FIG. 3  connected to an electrical device, 
           [0019]      FIG. 5  illustrates, in a schematic way, a view through an exemplary MEMS pump, and 
           [0020]      FIG. 6  illustrates, in a schematic way, a side view through an exemplary MEMS/piezoelectric fan. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    A “device” as the term is used herein, is to be broadly interpreted to include a radiotelephone, a camera (e.g., video and/or still image camera), a sound recorder (e.g., a microphone), and/or global positioning system (GPS) receiver; a personal communications system (PCS) terminal that may combine a cellular radiotelephone with data processing; a personal digital assistant (PDA); a laptop; and any other electrical device with need for temperature control, especially cooling electrical components. 
         [0022]      FIG. 1  is a perspective view of a connector  100  for an electrical device such as a mobile terminal, e.g. a mobile phone. The connector  100  comprises a housing  101 , a connection portion  102 , a number of apertures  103  and a cord  104 . The cord connects the connector to a power and/or data supply (not shown). In case of power supply, it may for example be a power adapter for adapting high voltage AC to DC suitable for operating or charging the batteries of the electrical device. 
         [0023]      FIG. 2  is a cut through the connector  100  of  FIG. 1 . According to this embodiment, the connector  100  comprises four MEMS pumps or fans  105  (only two illustrated in this view) provided with an intake  106  and an outlet  103 . 
         [0024]    The connector  100  further comprises wires  107  for supplying power to the device and wires  108  for supplying power to the fans or pumps. Other wires may be used for data communication, e.g. if the cord is a USB cable. 
         [0025]      FIG. 3  is a side view through a second exemplary embodiment of a connector  200 , comprising a housing  201 , connecting part  202 , outlets  203 , cord  204 , MEMS fan  205 , including intake  206 , power wire  207  and power supply wire  208 . In this case the fan  205  may comprise a piezoelectric MEMS fan having a piezoelectric fan blade, which moves when applied an electrical current in a direction that sucks in air and blows the air into the housing  201 . 
         [0026]      FIG. 4  illustrates in a schematic way the connector  200  according to  FIG. 3  connected to an electrical device  40 . The electrical device comprises a housing  41  having a connector portion  42  for connection to connector  200 , e.g. for charging a battery  43  of the device  40 . 
         [0027]    The device  40  at the connector portion  42  comprises intakes  44  corresponding to the outlets  203  of the connector  200 . The device may also be provided with one or several outlets  45 . 
         [0028]    According to one embodiment, when charging, especially fast charging the battery  43  of the device  40 , the battery  43  and other components  46 , such as charging regulator components may generate heat. To dissipate heat, the MEMS fan  205  is actuated to operate by sucking in air and blowing it through outlets  203  and inlets  44  into the device housing. The air path is illustrated with dashed line  47 . The air flow around the battery and components will dissipate the heat from the components out through the outlet  45  and cool down the battery  43  and components  46 . 
         [0029]    In one embodiment, the fan or pump may start when a fast charging begins and can be stopped when the device temperature is down at a normal level or when the charging is terminated. This means that temperature sensors may be incorporated in the device. These may also comprise of MEMS sensors. 
         [0030]    Preferably, the fan is powered from the charger side when (fast) charging of the battery starts, but the fan may likewise be controlled from the device side through the connector. 
         [0031]    The intakes on the device connector and external connector can be configured in several different ways: around the connectors, side by side to the connectors or inside thru the connectors. 
         [0032]    Having air channels inside the connector may make it possible to provide a compact solution. The air channels can be smaller so a higher air pressure may be needed. This solution can also give an EMC screening of the air channels as the ordinary shielding of the connector will be a part of the air channels. 
         [0033]    The air inlets and outlets may be provided with non return valves or MEMS valves to prevent moisture and dirt to enter the device/connector housing. 
         [0034]    The connector may be provided with an airtight seal towards the device. 
         [0035]    The fan and pump can have different embodiments to suite the mechanical properties of different connectors. Several fans can of course be used to increase performance and/or use the available space around the connector in the best way. 
         [0036]    Due to the mounting of the fan or pump in the external charging connector no additional space penalties or additional power consumption will affect the mobile device. 
         [0037]    The MEMS fan or pump may also be used to transport heat into the device, e.g. if the device is used in a cold environment. 
         [0038]    In the above examples, air is used as temperature control medium. However, other mediums such as other gases or liquids may also be used. In case of liquids, special closed channels for transporting the liquid medium can be implemented. The liquid medium may be used in devices with high heat generation. 
         [0039]      FIG. 5  illustrates a sectional view of an exemplary MEMS pump  50  comprising compression diaphragms  51 , cap plates  52 , and guide walls  53 . By applying a suitable alternating current, compression diaphragms  51  are move in the direction of arrows  54  and displace a medium through channels  55 . 
         [0040]      FIG. 6  illustrates a schematic piezoelectric fan  60 . The piezoelectric fan has a flexible blade  61 , e.g. made of mylar, that is set into motion by a piezoceramic bending element  62 . This bending element functions due to an ultra low power oscillating current of electricity. The electric field causes the piezoceramic to elongate, which bends the blade back and forth. The rapid flapping action produced creates air flow and cooling capacity. 
         [0041]    The term electrical connector as used herein may be defined broadly to include data connectors, modular connectors, component and device connectors, plug and socket connectors, etc. 
         [0042]    It should be noted that the word “comprising” does not exclude the presence of other elements or steps than those listed and the words “a” or “an” preceding an element do not exclude the presence of a plurality of such elements. It should further be noted that any reference signs do not limit the scope of the claims, that the invention may be implemented at least in part by means of both hardware and software, and that several “means”, “units” or “devices” may be represented by the same item of hardware. 
         [0043]    The foregoing description of embodiments of the present invention, have been presented for purposes of illustration and description. The foregoing description is not intended to be exhaustive or to limit embodiments of the present invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments of the present invention. The embodiments discussed herein were chosen and described in order to explain the principles and the nature of various embodiments of the present invention and its practical application to enable one skilled in the art to utilize the present invention in various embodiments and with various modifications as are suited to the particular use contemplated. The features of the embodiments described herein may be combined in all possible combinations of methods, apparatus, modules, systems, and computer program products.