Abstract:
A heating device and a temperature control device are provided. The heating device includes a heating element, and a heat conducting film disposed on the surface of the heating element, wherein the heat conducting film has a surface area that is larger than the contact area between the heat conducting film and the heating element. The heat conducting film is used for uniformly conducting heat generated by the heating element. Therefore, the existing non-uniform heating and slow heat dissipation problems for the heating element having a large surface area can be solved. Furthermore, because the metallic heat conducting film has good heat conduction, the heat can be quickly spread over a larger area to prevent localized overheating and damage to the heating element itself or the electrical product.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a heating equipment, and more particularly to a heating device and a temperature control device. 
         [0003]    2. The Prior Arts 
         [0004]    Nowadays, the heating elements usually include heating filaments, heating plates, heating disks, and heating tubes. However, when a large area is heated by using the heating filaments or heating plates, the heat distribution in such a large area will be non-uniform. Moreover, when the heating device with the metallic plate for conducting heat is used, heating and heat dissipating are slow. 
         [0005]    Conventionally, in the first case, the heating devices can have heating function but without temperature control, but for these heating devices, heating is slow, the heating temperature will be continuously raised, and electricity consumption is high. Conventionally, in the second case, the heating devices can also have heating with temperature control function, but for these heating devices, the temperature control is usually not accurate. However, if the heating devices have accurate temperature control function, they are very expensive. Furthermore, the current heating products will remain in the “on” state after they are switched on, which are power-consuming and not safe in use. 
         [0006]    Conventionally, the temperature control switches are usually used in the temperature control element. When the heating device is overheated, the electrical power for the heating device will be turned off by the temperature control switch, and when the heating device is needed to be heated, the electrical power for the heating device will be turned on by the temperature control switch. Consequently, the heating temperature becomes not stable for the heating device, and thereby the manual adjustment is required, which will cause inconvenience and inaccuracy. 
       SUMMARY OF THE INVENTION 
       [0007]    An objective of the present invention is to provide a heating device that can conduct heat uniformly and dissipate heat efficiently, and that is safe in use. 
         [0008]    Another objective of the present invention is to provide a temperature control device that can be accurately controlled, convenient to operate, and safe in use. 
         [0009]    The heating device of the present invention comprises a heating element; and a heat conducting film disposed on a surface of the heating element, wherein the heat conducting film has a surface area that is larger than the contact area between the heat conducting film and the heating element. The heat conducting film is a metallic film, and has a round shape, a triangular shape, or a polygonal shape. 
         [0010]    The temperature control device of the present invention comprises a power supply module, a controller chip, a temperature sensor module, a power supply control module, a pressure switch module, and a heating device, wherein an output end of the power supply module is connected with an input end of the power supply control module; input ends of the controller chip are connected respectively to an output end of the power supply module and an output end of the temperature sensor module; an output end of the controller chip is connected with an input end of the power supply control module and an input end of the pressure switch module; an output end of the pressure switch module is connected with an input end of the heating device; and an output end of the heating device is connected with an input end of the temperature sensor module. 
         [0011]    Heat generated by the heating element can be uniformly conducted by the heat conducting film. Therefore, the existing non-uniform heating and slow heat dissipation problems for the heating element having a large surface area can be solved. Furthermore, because the metallic heat conducting film has good heat conduction, the heat can be quickly spread over a larger area to prevent localized overheating and damage to the heating element itself or the electrical product. Furthermore, the heating device of the present invention can uniformly dissipate heat so that it can be applied to many different fields 
         [0012]    In the present invention, the heating process of the heating element is controlled by a controller chip that applies a variation of voltages to the heating element, rather than by a simple switching. Consequently, the temperature control can be more accurate. The pressure switch module is used in the present invention to improve the safety of the circuit. The desired temperature range can be set by the controller chip, and the temperature control device can provide automatic heating and cooling in the desired temperature range, and thereby the temperature control is well ensured. 
         [0013]    The heating device and temperature control device of present invention can be applied to far-infrared heating blankets, warming utensils, electric blankets, heating massage pillows, heating straps for motorcycle handles, heater for vehicle rearview mirror, far-infrared heating helmets, outdoor heating seat cushions, food warming bags, heaters for vehicle tires, heating jackets, heaters for massagers, heating pads, etc. In the present invention, the heating and temperature maintaining can be achieved effectively, and thereby the problems of the prior art can be overcome. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The present invention will be apparent to those skilled in the art by reading the following detailed description of a preferred embodiment thereof, with reference to the attached drawings, in which: 
           [0015]      FIG. 1  is a schematic view showing a heating device according to one embodiment of the present invention; 
           [0016]      FIG. 2  is a block diagram of a temperature control device according to one embodiment of the present invention; 
           [0017]      FIG. 3  is a circuit diagram of the temperature control device according to one embodiment of the present invention; 
           [0018]      FIG. 4  is a schematic view showing a pressure switch module according to one embodiment of the present invention; and 
           [0019]      FIG. 5  is a schematic view showing a heating element according to one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]      FIG. 1  is a schematic view showing a heating device according to one embodiment of the present invention. The heating device comprises a heating element  1 , and a heat conducting film  2  disposed on the surface of the heating element  1 . The heat conducting film  2  has a surface area that is larger than the contact area between the heat conducting film  2  and the heating element  1 . The heating element is selected from at least one of the group consisting of PTC heating elements, ceramic electrothermal boards, silicon carbide tube heating elements, metal heating elements, carbon crystal heating elements, graphite heating elements, quartz heating elements, molybdenum disilicide heating elements, electrothermal filaments, thick film stencil, carbon fiber quartz heating elements, nano electrothermal film heating plates, and superconductor heating elements. The heat conducting film  2  is a metallic film, such as aluminum foil film having good heat conducting properties. The metallic film can have a circular, triangular, polygonal, or other shape in order to fit the shapes of different devices. 
         [0021]      FIG. 2  is a block diagram of a temperature control device according to one embodiment of the present invention. As shown in  FIG. 2 , a temperature control device of the present invention comprises a power supply module  3 , a controller chip  4 , a temperature sensor module  5 , a power supply control module  6 , a pressure switch module  7 , and a heating device  8 . An output end of the power supply module  3  is connected with an input end of the power supply control module  6 . The two input ends of the controller chip  4  are connected respectively to the output end of the power supply module  3  and the output end of the temperature sensor module  5 . The output end of the controller chip  4  is connected with the input end of the power supply control module  6  and the input end of the pressure switch module  7 . The output end of the pressure switch module  7  is connected with the input end of the heating device  8 . The output end of the heating device  8  is connected with the input end of the temperature sensor module  5 . 
         [0022]      FIG. 3  is a circuit diagram of the temperature control device according to one embodiment of the present invention. The power supply module  3  is a power source BT 1 . The controller chip  4  has pins  1  to  14 . The power supply control module  6  comprises the first resistor R 1 , the second resistor R 2 , the third resistor R 3 , the first capacitor C 1 , the first light-emitting diode LED 1 , the second light-emitting diode LED 2 , the diode D 1 , the first switch SW 1 , the second switch SW 2 , and the third switch SW 3 . The temperature sensor module  5  comprises the fourth resistor R 4 , the fifth resistor R 5 , and the second capacitor C 2 . The heating device  8  comprises the heating element Rh. The pressure switch module  7  comprises a pressure switch SWp, a transistor Q 1 , and the eighth resistor R 8 . The positive electrode of the power source BT 1  is connected respectively to one end of the heating element Rh, one end of the first resistor R 1 , one end of the diode D 1 , one end of the first light-emitting diode LED 1 , one end of the second light-emitting diode LED 2 , and one end of the fourth resistor R 4 . The negative electrode of the power source BT 1  is connected to the ground. Another end of the first resistor R 1  is connected to pin  4 , RST of the controller chip  4 . The first light-emitting diode LED 1  is connected to one end of the third resistor R 3 . Another end of the third resistor R 3  is connected to pin  3 , XOUT of the controller chip  4 . The second light-emitting diode LED 2  is connected to one end of the second resistor R 2 . Another end of the second resistor R 2  is connected to pin  2 , XIN of the controller chip  4 . The negative electrode of the diode D 1  and one end of the first capacitor C 1  are connected respectively to pin  1 , VDD of the controller chip  4 . Another end of the first capacitor C 1  and pin  14 , VSS of the controller chip  4  are connected to the ground. Pin  7 , INT 1  of the controller chip  4  is connected to one end of the first switch SW 1 . Another end of the first switch SW 1  is connected to a low potential terminal. Pin  6 , PWM 0  of the controller chip  4  is connected to one end of the third switch SW 3 , and pin  5 , PWM 1  of the controller chip  4  is connected to one end of the second switch SW 2 . Another end of the third switch SW 3  and another end of the second switch SW 2  are connected to a low potential terminal. Another end of the fourth resistor R 4 , one end of the fifth resistor R 5 , and one end of the second capacitor C 2  are connected respectively to pin  11 , AIN 2  of the controller chip  4 . Another end of the fifth resistor R 5  and another end of the second capacitor C 2  are connected to the ground. Another end of the heating element Rh is connected to one end of the pressure switch SWp. Another end of the pressure switch SWp is connected to the drain of the transistor Q 1 . The gate of the transistor Q 1  is connected to one end of the eighth resistor R 8 , and the source of the transistor Q 1  is connected to the ground. Another end of the eighth resistor R 8  is connected to pin  9 , VREFH of the controller chip  4 . 
         [0023]    The temperature control device further comprises a power source detection module  9 . The input end of the power source detection module  9  is connected with the output end of the power supply module  3 , and the output end of the power source detection module  9  is connected with the input end of the controller chip  4 . The power source detection module  9  comprises the sixth resistor R 6 , the seventh resistor R 7 , and the third capacitor C 3 . One end of the sixth resistor R 6  is connected to the positive electrode of the power source BT 1 . Another end of the sixth resistor R 6 , one end of the seventh resistor R 7 , and one end of the third capacitor C 3  are connected respectively to pin  10 , AIN 1  of the controller chip  4 . Another end of the seventh resistor R 7  and another end of the third capacitor C 3  are connected to the ground. 
         [0024]    The first resistor R 1  has a resistance value of 100 K{tilde over (Ω)}. The second resistor R 2  has a resistance value of 5.1 KΩ ( 510 R). The third resistor R 3  has a resistance value of 5.1 KΩ ( 510 R). The fourth resistor R 4  has a resistance value of 100 KΩ. The fifth resistor is a negative temperature coefficient (NTC) thermistor of 100 KΩ. The sixth resistor has a resistance value of 200 KΩ. The seventh resistor has a resistance value of 100 KΩ. The eighth resistor has a resistance value of 2 KΩ. The first capacitor has a capacitance value of 0.1 μF ( 104 ), the second capacitor has a capacitance value of 0.1 μF ( 104 ), and the third capacitor has a capacitance value of 0.001 μF ( 102 ). The controller chip  4  can be a model SN8P2711P/S controller chip. The diode D 1  can be a model IN4148 diode. The transistor Q 1  can be a model ME2312 transistor. 
         [0025]      FIG. 4  is a schematic view showing a pressure switch module according to one embodiment of the present invention. Referring to  FIG. 4 , the pressure switch module  7  of the present invention is disposed between two fireproof insulation boards  10 , and the two fireproof insulation boards  10  are separated by a space using at least two elastic sponges  11 . 
         [0026]      FIG. 5  is a schematic view showing a heating element according to one embodiment of the present invention. Referring to  FIG. 5 , the heating element  1  is disposed between two fireproof insulation boards  10  so that the heating element  1  can be fireproof. 
         [0027]    The fireproof insulation boards used in the present invention are selected from at least one of the group consisting of silicone coated fiberglass fabric, basalt fiber fireproof fabric, acrylic fabric, 100% cotton flame retardant fabric, CVC flame retardant fabric, Cotton/Nylon flame retardant fabric, NOMEX flame retardant fabric, SM flame retardant fabric, blue fiber flame retardant fabric, aluminum foil fiberglass flame retardant fabric, coating flame retardant fabric, high silica fabric, silicon-titanium fabric, fire resistant Eva foam, and fire resistant sponge. 
         [0028]    The heat conducting film  2  dissipates uniformly heat produced from the heating element  1 . As a result, existing problems related to non-uniform heat emission and sensing of large surface areas, and slow heating and dissipation can be overcome. Point heating is replaced with surface heating, so that uniform heating can be obtained for large surface areas. Furthermore, the metallic heat conducting film has good conduction properties, and can dissipate heat quickly to prevent local overheating that may damage the electric appliance or the heating element  1 . In addition, uniform heat dissipation can allow the heating device to be suitable for a wider range of application. 
         [0029]    The present invention uses a controller chip that applies a variation of voltages to control heating of the heating element, rather than simple switching control. Therefore, the temperature control can be more accurate and power-saving. The addition of a pressure switch also allows the circuit to be safer and energy-saving. The controller chip can set the desired range of temperature, and the temperature control device can provide automatic heating and cooling in the temperature range, so that a constant temperature can be kept continuously. 
         [0030]    For example, the present invention can be used in far-infrared heating blankets, warming utensils, electric blankets, heating massage pillows, heating straps for motorcycle handles, heater for vehicle rearview mirror, far-infrared heating helmets, outdoor heating seat cushions, food warming bags, heaters for vehicle tires, heating jackets, heaters for massagers, heating pads, etc. The heating can be performed effectively by setting the desired temperature, which can overcome the problems of the prior art. 
         [0031]    The foregoing description is intended to only provide illustrative ways of implementing the present invention, and should not be construed as limitations to the scope of the present invention. While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may thus be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.