Patent Publication Number: US-2018041057-A1

Title: Charging devices

Description:
BACKGROUND 
     Communication devices, such as smart phones, tablets, and laptops, are equipped with a rechargeable power source for supporting operation of the communication device. The rechargeable power source is a power source, for example, a battery, which has power stored on it for supporting the operation of the communication devices. Owing to the operation of the communication devices, the power in the rechargeable power source gets depleted. The rechargeable power source may be charged using a charging device, for further operation. 
    
    
     
       BRIEF DESCRIPTION OF FIGURES 
       The detailed description is described with reference to the accompanying figures. The description and figures are merely example of the present subject matter and are not meant to define the scope of the subject matter as claimed. 
         FIG 1  illustrates a block diagram of charging device, according to an example of the present subject matter. 
         FIG. 2  illustrates a block diagram of a charging device, according to an example of the present subject matter. 
         FIG. 3  illustrates a block diagram of a charging device, according to an example of the present subject matter. 
         FIG. 4  illustrates a block diagram of a charging device, according to an example of the present subject matter. 
     
    
    
     DETAILED DESCRIPTION 
     Charging devices are used for charging communication devices, such as laptops, tablets, mobile phones, personal digital assistants, and smart phones. During operation of a charging device, components of the charging device may heat up, for example, due to prolonged use. Overheating of a component may affect the functioning of the component or, in some cases, may result in damaging the component. Furthermore, overheating of the components may manifest in the form of the outer surface of the charging device heating up. In such a case, users of the charging device may experience discomfort due to the heated surface of the charging device or sustain minor heat related injuries, if they come in contact with the heated surface. 
     In order to avoid over-heating and to maintain the temperature of the components within their suitable operating temperature, the charging devices are provided with heat sinks. A heat sink is a device which may be mounted onto, and in contact with, a component for dissipating heat generated by the component. The heat sink extracts the heat generated by the component and dissipates it to the external environment thereby maintaining the temperature of the component. The heat sink comprises a base and a plurality of pins or fins extending from the base. Generally, the heat sink is so positioned such that the base of the heat sink abuts the component while a tip end of the pins is facing a surface of the charging device. Generally, a material, such as a metal or an alloy, exhibiting high thermal conductance may be used for fabricating the heat sink. The high thermal conductance of the material facilitates in dissipation of the heat. 
     Though the high thermal conductance of the material facilitates in dissipation of heat, it also causes the heat sink to heat up. Since the components and the heat sink may be generally enclosed within the charging device, heating up of the heat sink may, in turn, result in heating of the body of the charging device. For instance, within the charging device the heat sink may be housed within a casing. In such a case, certain inner regions of the casing may be proximal to the pins of the heat sink. As a result, in operation the tip end of the pins may have the highest temperatures, which may cause an inner surface and the inner environments of the charging device, in vicinity of the tip ends, to heat up. The heat thus generated may be subsequently transferred from the inner regions to the outer surfaces of the charging device. As mentioned above, heating up of the surface may cause discomfort to a user of the charging device or may put the user at a risk of sustaining heat related injuries. In another example, if the heat sink is fabricated from a material having low thermal conductance, the heat sink may not effectively dissipate the generated heat. As a result, the components of the charging device may overheat and may, in some cases, get damaged over prolonged usages. 
     The present subject matter relates to a charging device, and other such charging apparatus, incorporating a planar supporting structure which is utilized for effective dissipation of heat generated from various components of the charging device. 
     According to an example, the planar supporting structure includes a first surface and a second surface. The first surface may include a plurality of projections. The projections may extend from the first surface and terminate at an end, referred to as a tip end. The projections may have different shapes and profiles. In an example, the planar supporting structure may be a heat sink wherein the projections may be pins, which extend outwardly from the base of the heat sink. Each of such pins may include a tip end. 
     In an example, the first surface may have a thermal radiation coating applied over it. The thermal radiation coating affects radiation of heat from the first surface. In an implementation, the entire area of the first surface may be coated with the thermal radiation coating. In such a case, the thermal radiation coating thus applied, may also coat the surfaces of the tip end of each of the projections. In another implementation, a portion or specific portions of the first surface may be coated with the thermal radiation coating. The thermal radiation coating may enhance the rate at which heat is dissipated by the first surface. The thermal radiation coating may be based on various allotropic forms of carbon, such as graphene, carbon nanotubes, diamond like carbon, and graphite. Additionally, a portion of the second surface of the planar supporting structure is coated with a thermal conductive coating for affecting conductance and extraction of heat from the components. When mounted with components of the charging device, the coating of the thermally conductive material is interspersed between the second surface and the components. 
     In continuation to the above, the tip ends of the projections may also have a thermal insulation coating applied over a portion of the thermal radiation coating for minimizing heat dissipated through the tip ends. As a result, even though the tip end may get heated the most, the environment surrounding the tip end or any inner surfaces of the charging device, may not get heated up as much. 
     In another example, prior to applying the thermal radiation material, the tip end of the projections is initially coated with the thermal insulation coating. Once the thermal insulation coating is applied to the tip end of the projections, the remaining surface area of the first surface is applied with the thermal radiation coating. 
     As explained in the present description, effective heat dissipation in conjunction with suitable insulation against the heat dissipated is achieved in charging device incorporating the planar supporting structure. Thus, overheating and related damages, of both, the integral components and the surface of the charging device may be avoided. Additionally, discomfort to the user or likelihood of undesirable heat related injuries due to physical contact with the charging device is also reduced. 
     The above aspects are further described in conjunction with figures and associated description below. It should be noted that the description and figures merely illustrate the principles of the present subject matter. Therefore, various arrangements that embody the principles of the present subject matter, although not explicitly described or shown herein, can be devised from the description and are included within its scope. 
       FIG. 1  illustrates a block diagram of a charging device  100 , according to an example of the present subject matter. In an example, the charging device  100  may be a wireless charger for charging communication devices, such as smart phones, tablets, and personal digital assistants, supporting wireless charging technology. Generally, charging devices, such as the charging device  100 , charge communication devices when such communication devices are placed in immediate proximity of the charging device  100 . 
     In an example, the charging device  100  may include a housing (not shown in figure), which in turn houses a planar supporting structure  102  of predefined thickness. The planar supporting structure  102  may be composed of metallic materials, such as aluminum, magnesium, zinc, titanium, niobium, copper, iron, silicon carbide, or any alloys thereof. In another example, as will be described later in  FIG. 2 , the planar supporting structure  102  may be fabricated using a material, such as plastic. 
     The planar supporting structure  102  includes two surfaces, namely a first surface  104  and a second surface  106 . As would be explained in the later portions of the present description, the planar supporting structure  102  may support one or more components of the charging device  100 . The first surface  104  of the planar supporting structure  102  comprises a plurality of projections  108 , extending from the first surface  104 . Although  FIG. 1  illustrates the projections  108  extending orthogonally from the first surface  104 , the projections  108  may be inclined at any angle to the first surface  104 , without deviating from the scope of the present subject matter. Each of the projections  108  may extend from their respective bases (on the first surface  104 ), and may terminate at an end  110 , also referred to as a tip end  110 . The projections  108  may also be of different shapes. For example, the projections  108  may be semi-spherical, pyramidal, semi-oval, trapezoidal, or rectangular in shape. The projections  108  help to increase the effective surface of the first surface  104 , and also thus increase heat dissipation. 
     In an example, the first surface  104  and the tip ends  110  have a thermal radiation coating  112 . The thermal radiation coating  112  may be composed of a material that may enhance the rate of dissipation of heat through thermal radiation. In such cases, such materials may be considered as possessing high thermal radiance, i.e., materials which assist in rate of dissipation of thermal energy through radiation. For instance, the thermal radiation coating  112  may be of different types of material. For example, the thermal radiation coating  112  may based on any one of the allotropic forms of carbon, such as graphene, carbon nanotubes, diamond like carbon, and graphite. Furthermore, various combinations of such materials may also be used to prepare the thermal radiation coating  112  without deviating from the scope of the present subject matter. 
     Furthermore, the tip end  110  of each of the projections  108  may have a thermal insulation coating  114 . In an example, the thermal insulation coating  114  is so applied, such that it overlaps the thermal radiation coating  112 . The thermal insulation coating  114  may be based on a material which inhibits the conduction of heat, i.e., it is a thermal insulator. The thermal insulation coating  114  reduces the heat dissipated in the surrounding environment and the inner surface of the charging device  100  from the tip ends  110 . Thus, the probability of a user of the charging device  100  experiencing discomfort or sustaining heat related injuries while placing or retrieving a communication device from the surface of the charging device  100  is reduced. 
     The thermal insulation coating  114  may compose of materials, such as fiberglass, mineral wool, cellulose, calcium silicate, cellular glass, and an elastomer. Furthermore, various combinations of such materials may also be used to prepare the thermal insulation coating  114  without deviating from the scope of the present subject matter. 
     In an example, the second surface  106  of the planar supporting structure  102  may have a thermal conductive coating  116  to affect transfer of heat generated by various components of the charging device  100 , through conductance. The thermal conductive coating  116  may be of a material that may enhance the thermal conductance of the planar supporting structure  102 . Additionally, the thermal conductive coating  116  may also enhance the thermal conductance of a component abutted, i.e., in physical contact with the thermal conductive coating  116 . The thermal conductive  116  may be fabricated using one of an allotropic form of carbon and a powdered form of a ceramic material. In an example where the planar supporting structure  102  is composed of a metallic material, the thermal conductive coating  116  may be coated over a portion of the second surface. 
     The charging device  100  may further comprise a magnetic core  118  disposed over the second surface  106 . The magnetic core  118  may be used in conjunction with a coil (not shown in figure) for producing an electromagnetic field for wirelessly charging communication devices. In an example, the magnetic core  118  may be fabricated using metallic material, for example, using copper. In an example, as illustrated in the figure, the magnetic core  118  may be abutted to the portion of the second surface having the thermal conductive coating  116  at a surface  120  of the magnetic core  118 . The charging device  100  may further comprise a cover  122 . The cover  122  may be comprise materials, such as plastic, and may provide support for the components of the charging device  100 . 
     Further, in an example, a component or a plate (not shown in the figure) comprising a ferrite material may be disposed under the magnetic core  118  to reduce the effect of the eddy currents induced by the magnetic core  118 . 
     During prolonged use of the charging device  100 , the magnetic core  11  may heat up. In such a case, the thermal conductive coating  116  may facilitate conductance of the heat through the second surface  106  of the planar supporting structure  102 . Owing to the thermal conductive coating  116 , the heat may conduct from the magnetic core  118  to the planar supporting structure  102 , at a faster rate. Due to conduction, the heat extracted from the magnetic core  118  is transmitted to the first surface  104  of the planar supporting structure  102 . Form the first surface  104 , the heat may dissipate into the air surrounding the planar supporting structure  102  through the projections  108 . The thermal radiation coating  112  coated on the first surface  104  may facilitate the dissipation of heat at a faster rate. Further, the thermal insulation coating  114  coated on the tip ends  110  prevents heat dissipated from the tip ends  110  and thus, a surface of the charging device  100  in vicinity to the tip ends  110  may not heat up. Thus, instances of a user experiencing discomfort or sustaining heat related injuries are reduced. 
       FIG. 2  illustrates a block diagram of a charging device  200 , according to an example of the present subject matter. The charging device  200  comprises a planar supporting structure  202 , such as the planar supporting structure  102 . Similar to the example discussed in conjunction with  FIG. 1 , the planar supporting structure  202  also includes a first surface  204  and a second surface  206 . The first surface  204  of the planar supporting structure  202  further includes a plurality of projections  208 , such as the projections  108 . The projections  208  extend from the first surface  204  till a tip end  210 . In an example, as illustrated in the figure, the planar supporting structure  202  may be fabricated using non-metallic materials, such as plastics. Usage of such materials for fabricating the charging device  200  may provide a light weight, high throughput and a cost effective approach for fabricating the charging device  200 . In the present example, the entire second surface  206  of the planar supporting structure  202  may have a thermal conductive coating  216 , such as the thermal conductive coating  116 , coated. The thermal conductive coating  2  enhances the thermal conductivity of the plastic. 
     In the present example, each of the tip ends  210  of the projections  208  has a thermal insulation coating  214 , similar to the thermal insulation coating  114 . The thermal insulation coating  214  is provided on the tip ends  210  in a manner such that the thermal insulation coating  214  overlaps a thermal radiation coating  212 , such as the thermal radiation coating  112 , extending over the first surface  204 . As also illustrated in  FIG. 2 , the charging device  200  may further include a magnetic core  218 , such as the magnetic core  118 . Although the present illustration depicts the magnetic core  218 , the charging device  200  may also include additional components (not shown in the figure) without deviating from the scope of the present subject matter. 
     The magnetic core  218  is so placed, such that it is in physical contact with the second surface  206 , with the thermal conductive coating  216  interspersed between. The planar supporting structure  202  provides support for the magnetic core  218 , and for other components. Additionally, a cover  222  of the charging device  200  may also provide support to the other components of the charging device  200 . 
     In operation, the heat generated by the magnetic core  218  (or other components) in contact with the second surface  206 , is extracted by the thermal conductive coating  216 . The thermal conductive coating  216  allows the portion of the thermal radiation coating  212  provided on the first surface  204 , to be also heated by way of conduction. The surface area of the first surface  204  is exposed to the inner environment of the charging device  200 . The heat conducted by the portion of the thermal radiation coating  212  on the first surface  204  is dissipated to the inner environment of the charging device  200 . Furthermore, since the tip ends  210  of the projections  208  are provided with the thermal insulation coating  214 , the heating of the tip ends  210  do not result in heating of the inner surface of the charging device  200 . 
       FIG. 3  illustrates a block diagram of a charging device  300  for charging electronic devices, according to an example of the present subject matter. The charging device  300 , in an example, may comprise a plurality of components  302 - 1 , . . . ,  302 -N, collectively referred to as the components  302 , and individually referred to as component  302 . Examples of components  302  may include, but are not limited to, transistors, resistors, charging coils, rectifiers, and other such components used in charging circuitry. 
     The charging device  300  further comprises a supporting plane  304  having a first surface  306  and a second surface  308 . The components  302  are so positioned, such that they are in physical contact with the second surface  308 . As will be described below, the second surface  308  may have a coating coated intermediary to the second surface  308  and the top surfaces of the components  304  for facilitating effective dissipation of heat from the components  304 . 
     In an example, the first surface  306  comprises a plurality of protrusions  310  extending from the first surface  306  and terminating at a tip end  312 . The protrusions  310  provide for increasing a surface area of the first surface  306  of the supporting plane  304  for affecting effective dissipation of heat through radiation. In the example, the tip ends  312  are provided with a thermal insulation coating  314 , such as the thermal insulation coating  114  to reduce the heat dissipated from the tip ends  312 . As should be noted, the components  302  and the supporting plane  304  may be enclosed in a housing of the charging device  300 . In the present example, certain inner portions of the housing would be proximal to the tip ends  312 . With the thermal insulation coating  314  applied to the tip ends  312 , the heat being radiated by the tip ends  312  is reduced. As a result, heating of inner portions of the charging device  300  or other components in vicinity to the tip ends  312  may be minimized. Thus, probability of a user experiencing discomfort or sustaining minor heat related injuries due to overheating of the surface of the charging device  300  is reduced. In an example, the thermal insulation coating  314  may be prepared from materials, such as phenolic foam, vermiculite, polyurethane foam, and polystyrene foam. In an example, the polystyrene foam may be either partially or completely immersed in a polymeric resin. The remainder of the first surface  306  may be coated with a thermal radiation coating  316 , such as the thermal radiation coating  112 , which enhances radiation of heat from the first surface  306 . 
     The second surface  308  of the supporting plane  304  may have a thermal conductive coating  318 , such as the thermal conductive coating  116 . The thermal conductive coating  318  affects conductance of heat from both, the components  302  and the supporting plane  304 . As illustrated in the figure, the top surfaces of the components  302  intersperse the thermal conductive coating  318 . The thermal conductive coating  318  may be fabricated using allotropic forms of carbon. In another example, the thermal conductive coating  318  may be composed of a powdered form of metal. Further, the charging device  300  may have a cover  320 , similar to the cover  122 , for providing support for components of the charging device  300 . 
       FIG. 4  illustrates a block diagram of a charging device  400 , according to another example of the present subject matter. The charging device  400 , in an example, includes a plurality of components  402 - 1 , , . . . ,  402 -N, collectively referred to as the components  402 , and individually referred to as component  402 . For instance, the charging device  400  may include components, such as transistors resistors, induction coil, and power converters, integral to charging circuitry. 
     For facilitating effective dissipation of heat, the charging device  400 , in an example, includes a planar supporting structure  404 . The planar supporting structure  404  has a first surface  406  and a second surface  408  onto which the components  402  are disposed. In order to enhance the conductance of heat generated from the components  402 , the second surface  408 , has a thermal conductive coating  410 , such as the thermal conductive coating  116 . As can be seen in the figure, the components  402  are disposed over the second surface  408  such that a top surface of each of the components  402  intersperses the thermal conductive coating  410 . 
     The charging device  400  further includes a heat sink  412  integrally coupled to the first surface  408  of the planar supporting structure  404 . The heat sink  412  includes a surface having a plurality of projections  414 . The projections  414 , in effect, enhance a surface area of the heat sink  412  to facilitate dissipation of heat from the heat sink  412 . 
     In the present example, each of the projections  414  has a tip end  416  coated with a thermal insulation coating  418 , such as the thermal insulation coating  114 . During operation, in a case where the components  402  may cause heating of the heat sink  412 , the thermal insulation coating  418  reduces the heat dissipated from the tip ends  416 . As a result, a surface of the charging device  400  in vicinity to the tip ends  416  may not overheat and probability of discomfort to a user of the charging device  400  is reduced. Further the remainder of the surface of the heat sink  412  is provided with a thermal radiation coating  420 , such as the thermal radiation coating  112 . The thermal radiation coating  420  affects the dissipation of heat into surrounding medium inside the charging device  400 . Further, as shown in the figure, the charging device  400  may have a cover  422 , similar to the cover  122 , for providing support for components of the charging device  400 . The cover  422 , in an example, may be fabricated from materials, such as plastics. 
     Although examples for charging devices have been described in language specific to structural features and/or methods, it is to be understood that the appended claims are not limited to the specific features or methods described. Rather, the specific features and methods are disclosed as examples for charging devices.