Patent Publication Number: US-9900951-B1

Title: Lamp having the thermal sensing elements disposed at optimal positions and thermal controlling method thereof

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The instant disclosure relates to a lamp; in particular, to a lamp having the thermal sensing elements disposed at optimal positions and a thermal controlling method thereof. 
     2. Description of Related Art 
     Light emitting diodes have been placed at high value in recent years, especially the high-brightness light emitting diodes (HB LEDs) for which the demand is greatly increased and this has set off a frenzy in the field. High-brightness light emitting diodes have the advantages of energy saving, long product life, high durability and high brightness and short response time compared to conventional incandescent bulbs. Currently, high-brightness light emitting diodes are not only applied to general illumination, commercial illumination, vehicle illumination, outdoor advertising billboards and traffic information signs, but also have become a strongly integrated item in a variety of fields of LCD backlight modules, smart phones and digital camera flashlight modules along with the improvement of consumer electronics. 
     Most of electric energy will be converted to thermal energy and only a small amount of electric energy will be converted to light during the usage of light emitting diodes. High high-brightness light emitting diodes consume most of the electric energy among them. For this reason, the electric current for light emitting diodes must be carefully designed. 
     Light emitting diodes have rated values for limited temperature in operating mode. If light emitting diodes are used under high temperature for a long time without sufficient heat dissipation, the light emitting diodes will accelerate aging therefore reducing illumination efficiency and shortening life. The dissipation issue is very important for light emitting diodes applied to light bulbs, especially when applied to hermetic lamps or insulator lamps. For instance, the overheating temperatures inside the lamp due to insufficient dissipation will result in not only the damage of the light emitting diodes, but also the damage of related electronic components, especially a capacitor, of the power supply inside the lamp. Hence, it is one of the major topics of the field to effectively control the internal temperature inside the light emitting diode lamp so as to avoid damage of the internal components. 
     Therefore, there is a need of a solution which overcomes the above disadvantages. 
     SUMMARY OF THE INVENTION 
     The object of the instant disclosure is to provide a lamp with a sensing element disposed at an optimal position and the sensing controlling method thereof, which can immediately monitor the internal temperature of the lamps by at least a first thermal sensing element (or at least a second thermal sensing element) disposed in the lamp, and then can immediately adjust the output power of a power source module. This is to avoid and solve the lamp damage problem caused by overheating, and relatively promote the product life of the lamp. 
     In order to achieve the aforementioned objects, according to an embodiment of the instant disclosure, a lamp having thermal sensing elements disposed at optimal positions in which a lamp cold zone and a lamp heat zone are defined is provided, the lamp comprises: a heat sink, a light-emitting module, a power supply module and a controlling module. The heat sink comprises a plurality of heat dissipating fins spaced apart from each other and a connecting part, wherein a heat dissipating channel is formed between each two of the plurality of heat dissipating fins, and the plurality of heat dissipating fins surround a central axis of the heat sink to form an accommodating space. The light-emitting module comprises a substrate and at least one light-emitting unit, wherein the substrate is disposed at the connecting part of the heat sink, and the at least one light-emitting unit is disposed on the substrate. The power supply module is disposed in the accommodating space, wherein a central channel is formed between the power supply module and the plurality of heat dissipating fins, the central channel communicates with the heat dissipating channel, and the power supply module comprises a conductive base and a power source module. The conductive base is disposed away from the substrate for connecting to an external power supply. The power source module is electrically connected to the conductive base and the light-emitting module, wherein the power source module comprises at least one thermal sensitive element disposed at the lamp cold zone. The controlling module comprises at least one first thermal sensing element and a processing unit, wherein the at least one first thermal sensing element is disposed adjacently to the substrate in the lamp heat zone, the at least one first thermal sensing element may sense a first operating temperature, and the processing unit is electrically connected to the power source module and the at least one first thermal sensing element; and the processing unit may lower an output power of the power source module to the light-emitting module when the first operating temperature is greater than or equal to a first critical operating temperature of the light-emitting module. The lamp cold zone has a first cold zone boundary and a second cold zone boundary, the lamp heat zone has a first heat zone boundary and a second heat zone boundary; the first heat zone boundary is coplanar with a surface of the substrate on which the at least one light-emitting unit is disposed, the first cold zone boundary is at the bottom of the conductive base, and a distance between the first cold zone boundary and the first heat zone boundary is an internal element distance; a first distance between the second heat zone boundary and the first heat zone boundary is one-third of the internal element distance, and a second distance between the second cold zone boundary and the first cold zone boundary is one-third of the internal element distance. 
     In order to achieve the aforementioned objects, according to an embodiment of the instant disclosure, a lamp having thermal sensing elements disposed at optimal positions in which a lamp cold zone and a lamp heat zone are defined is also provided, the lamp comprises: a heat sink, a light-emitting module, a power supply module and a controlling module. The heat sink comprises a plurality of heat dissipating fins spaced apart from each other and a connecting part, wherein a heat dissipating channel is formed between each two of the plurality of heat dissipating fins, and the plurality of heat dissipating fins surround a central axis of the heat sink to form an accommodating space. The light-emitting module comprises a substrate and at least one light-emitting unit, wherein the substrate is disposed at the connecting part of the heat sink, and the at least one light-emitting unit is disposed on the substrate. The power supply module is disposed in the accommodating space, wherein a central channel is formed between the power supply module and the plurality of heat dissipating fins, the central channel communicates with the heat dissipating channel, and the power supply module comprises a conductive base and a power source module. The conductive base is disposed away from the substrate for connecting to an external power supply. The power source module is electrically connected to the conductive base and the light-emitting module, wherein the power source module comprises at least one thermal sensitive element disposed at the lamp cold zone. The controlling module comprises at least one first thermal sensing element and a processing unit, wherein the at least one first thermal sensing element is disposed adjacently to the substrate in the lamp heat zone, the at least one first thermal sensing element may sense a first operating temperature, and the processing unit is electrically connected to the power source module and the at least one first thermal sensing element; and the processing unit may lower an output power of the power source module to the light-emitting module when the first operating temperature is greater than or equal to a first critical operating temperature of the light-emitting module. Wherein, the lamp cold zone has a first cold zone boundary and a second cold zone boundary, the lamp heat zone has a first heat zone boundary and a second heat zone boundary; the first heat zone boundary is a safety distance toward to the conductive base from a surface of the substrate on which the at least one light-emitting element is disposed, the first cold zone boundary is at the bottom of the conductive base, and a distance between the first cold zone boundary and the first heat zone boundary is an internal element distance; a first distance between the second heat zone boundary and the first heat zone boundary is one-third of the internal element, and a second distance between the second cold zone boundary and the first cold zone boundary is one-third of the internal element distance. 
     In order to achieve the aforementioned objects, according to an embodiment of the instant disclosure, a thermal controlling method for lamp is provided, which comprises the following steps: step S1: providing a lamp comprising a heat sink, a light-emitting module and a power supply module, wherein the heat sink comprises a plurality of heat dissipating fins spaced apart from each other, a heat dissipating channel is formed between each two of the plurality of heat dissipating fins, and the plurality of heat dissipating fins surround a central axis of the heat sink to form an accommodating space, and the light-emitting module is disposed at one end of the heat sink. Step S2: disposing the power supply module into the accommodating space to form a central channel between the power supply module and the plurality of heat dissipating fins, wherein central channel communicates with the heat dissipating channel, the power supply module comprises a controlling module and a power source module electrically connected to each other, the controlling module comprises at least one first thermal sensing element and a processing unit, the power source module comprises at least one thermal sensitive element away from the light-emitting module and disposed in a lamp cold zone of the lamp. Step S3: disposing the at least one first thermal sensing element adjacent to a substrate of the light-emitting module to make the at least one first thermal sensing element in a lamp heat zone of the lamp. Step S4: operating the lamp. Step S5: determining whether a first operating temperature of the at least one first thermal sensing element is greater than or equal to a first critical operating temperature of the light-emitting module by utilizing the processing unit. Step S6: utilizing the processing unit to lower an output power of the power source module to the light-emitting module after the processing unit has determined the first operating temperature is greater than or equal to the first critical operating temperature. The lamp cold zone has a first cold zone boundary and a second cold zone boundary, the lamp heat zone has a first heat zone boundary and a second heat zone boundary; the first heat zone boundary is coplanar with a surface of the substrate on which the at least one light-emitting unit is disposed, the first cold zone boundary is at the bottom of the conductive base, and a distance between the first cold zone boundary and the first heat zone boundary is an internal element distance; a first distance between the second heat zone boundary and the first heat zone boundary is one-third of the internal element distance, and a second distance between the second cold zone boundary and the first cold zone boundary is one-third of the internal element distance. 
     In order to achieve the aforementioned objects, according to an embodiment of the instant disclosure, a thermal controlling method for lamp is also provided, which comprises following steps. Step S1: providing a lamp comprising a heat sink, a light-emitting module and a power supply module, wherein the heat sink comprises a plurality of heat dissipating fins spaced apart from each other, a heat dissipating channel is formed between each two of the plurality of heat dissipating fins, and the plurality of heat dissipating fins surround a central axis of the heat sink to form an accommodating space, and the light-emitting module is disposed at one end of the heat sink. Step S2: disposing the power supply module into the accommodating space to form a central channel between the power supply module and the plurality of heat dissipating fins, wherein central channel communicates with the heat dissipating channel, the power supply module comprises a controlling module and a power source module electrically connected to each other, the controlling module comprises at least one first thermal sensing element and a processing unit, the power source module comprises at least one thermal sensitive element away from the light-emitting module and disposed in a lamp cold zone of the lamp. Step S3: disposing the at least one first thermal sensing element adjacent to a substrate of the light-emitting module to make the at least one first thermal sensing element in a lamp heat zone of the lamp. Step S4: operating the lamp. Step S5: determining whether a first operating temperature of the at least one first thermal sensing element is greater than or equal to a first critical operating temperature of the light-emitting module by utilizing the processing unit. Step S6: utilizing the processing unit to lower an output power of the power source module to the light-emitting module after the processing unit has determined the first operating temperature is greater than or equal to the first critical operating temperature. The lamp cold zone has a first cold zone boundary and a second cold zone boundary, the lamp heat zone has a first heat zone boundary and a second heat zone boundary; the first heat zone boundary is a safety distance from a surface of the substrate on which the at least one light-emitting unit is disposed, the first cold zone boundary is at the bottom of the conductive base, and a distance between the first cold zone boundary and the first heat zone boundary is an internal element distance; a first distance between the second heat zone boundary and the first heat zone boundary is one-third of the internal element distance, and a second distance between the second cold zone boundary and the first cold zone boundary is one-third of the internal element distance. 
     A lamp having thermal sensing element disposed at optimal position and the sensing controlling method thereof provided by the instant disclosure have advantages that the instant disclosure can individually sense temperatures of the substrate of the light-emitting module and of the thermal sensitive elements of the lamps by at least a first thermal sensing element (or at least a second thermal sensing element) disposed in the lamp, thereby determining if the light-emitting module and each of thermal sensitive element are overheating, then immediately adjusting the output power of a power source module. This is to avoid and solve the lamp damage problem caused by over heat. 
     In order to further the understanding regarding the instant disclosure, the following embodiments are provided along with illustrations to facilitate the disclosure of the instant disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 and 2  show exploded diagrams of a lamp having the thermal sensing elements disposed at optimal positions according to a first embodiment of the instant disclosure; 
         FIG. 3  shows a cross-sectional view of a lamp having the thermal sensing elements disposed at optimal positions according to a first embodiment of the instant disclosure; 
         FIG. 4  shows a diagram of a lamp cold zone and a lamp heat zone of a lamp having the thermal sensing elements disposed at optimal positions according to a first embodiment of the instant disclosure; 
         FIG. 5  shows a diagram of a lamp cold zone and a lamp heat zone of a lamp having the thermal sensing elements disposed at optimal positions according to a second embodiment of the instant disclosure; 
         FIG. 6  shows a diagram of a lamp cold zone and a lamp heat zone of a lamp having the thermal sensing elements disposed at optimal positions according to a third embodiment of the instant disclosure; 
         FIG. 7  shows a diagram of a lamp cold zone and a lamp heat zone of a lamp having the thermal sensing elements disposed at optimal positions according to a forth embodiment of the instant disclosure; 
         FIG. 8  shows a cross-sectional view of a lamp having the thermal sensing elements disposed at optimal positions according to a fifth embodiment of the instant disclosure; 
         FIG. 9  shows a cross-sectional view of a lamp having the thermal sensing elements disposed at optimal positions according to a sixth embodiment of the instant disclosure; 
         FIG. 10  shows a cross-sectional view of a lamp having the thermal sensing elements disposed at optimal positions according to a seventh embodiment of the instant disclosure; 
         FIG. 11  shows a cross-sectional view of a lamp having the thermal sensing elements disposed at optimal positions according to an eighth embodiment of the instant disclosure; 
         FIG. 12  shows a flow diagram of a thermal controlling method for lamps according to a first embodiment of the instant disclosure; 
         FIG. 13  shows a flow diagram of a thermal controlling method for lamps according to a second embodiment of the instant disclosure; 
         FIG. 14  shows a flow diagram of a thermal controlling method for lamps according to a third embodiment of the instant disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The aforementioned illustrations and following detailed descriptions are exemplary for the purpose of further explaining the scope of the instant disclosure. Other objectives and advantages related to the instant disclosure will be illustrated in the subsequent descriptions and appended drawings. 
     First Embodiment 
     Please refer to  FIGS. 1 to 4 , which are diagrams of a lamp having the thermal sensing elements disposed at optimal positions according to a first embodiment of the instant disclosure. As shown in the figures, a lamp  1  having the thermal sensing elements disposed at optimal positions includes a heat sink  10 , a light-emitting module  20 , a power supply module P and a cover S. The power supply module P includes a conductive base  40  and a controlling module  50 . The heat sink  10  includes a plurality of heat dissipating fins  11 , a heat dissipating channel  111  is formed between each two of the plurality of heat dissipating fins  11 ; the plurality of heat dissipating fins  11  surround a central axis of the heat sink  10  to form an accommodating space SP. The light-emitting module  20  comprises a substrate  21  and multiple light-emitting units  22 , and these light-emitting units  22  are disposed on the substrate  21 , and the substrate  21  is disposed at the connecting part  12  of the heat sink  10 . Preferably, each light-emitting unit  22  could be light emitting diodes (LED) or high-brightness light emitting diodes (HB LED). 
     The power supply module P is disposed in the accommodating space SP, a central channel  112  is formed between the power supply module P and the plurality of heat dissipating fins  11 , and the central channel  112  communicates the heat dissipating channels  111 . Specifically, the power supply module P has a hollow tube P 1 , the conductive base  30  is disposed at one end of the hollow tube P 1 , and the power source module  40  and the controlling module  50  are disposed in the hollow tube P 1 . The power supply module P is disposed in the accommodating space SP, therefore the hollow tube P 1  is completed surrounded by the heat dissipating fins  11 , and the central channel  112  is formed between the hollow tube P 1  and the heat dissipating fins  11 . That is, only the conductive base  30  is exposed outside the heat sink  10 , and the remainder are disposed in the heat sink  10  and surrounded by the heat dissipating fins  11 , while the power supply module P is disposed in the accommodating space SP. Wherein, the power supply module P is disposed in the accommodating space SP, while the other end of the hollow tube P 1  opposite the end provided with the conductive  30  is adjacent to or connected to a connecting part  12  of the heat sink  10 . In other words, the other end of the hollow tube P 1  without the conductive base  30  corresponds to the position adjacent to the light-emitting module  20  while the power supply module P is disposed in the accommodating space SP. 
     The power source module  40  is disposed in the hollow tube P 1 , and the power source module  40  includes at least one thermal sensitive element  41  (e.g. various capacitors, IC chips, etc.), and the at least one thermal sensitive element is disposed adjacent to the conductive base  30  and in a lamp cold zone A. In one actual application, the conductive base  30  could be but is not limited to a screw thread base or pin base. The power source module  40  further comprises DC-AC conversion units, a voltage regulating unit, a voltage transforming unit, and a line filter, etc. 
     The controlling module  50  is disposed in the hollow tube P 1 , and the controlling module  50  includes a first thermal sensing element  51  and a processing unit (not shown, such as a microprocessor). The first thermal sensing element  51  is disposed adjacent to the connecting part  12  of the heat sink  10  to sense a first operating temperature T 1  of the nearby area thereof. That is, the first thermal sensing element  51  is disposed adjacent to the substrate  21  of the light-emitting module  20  to sense the first operating temperature T 1  near the substrate  21 . It is noted that the first thermal sensing element  51  could be a safety distance (not shown, e.g. 0˜7 mm) from the substrate  21 . In another application, the first thermal sensing element  51  could be disposed at one side of the substrate  21  on which the light-emitting units  22  are disposed. In other words, the first thermal sensing element  51  could be disposed on the upper side or the lower side of the substrate  21  depending on the need. The processing unit is electrically connected to the power source module  40  and the first thermal sensing element  51 . The processing unit adjusts correspondingly the light-emitting module  20  and the power source module  40  according to the temperature information sensed by the first thermal sensing element  51 . 
     The processing unit of the controlling module  50  is used to determine whether the sensed first operating temperature T 1  is greater than a first critical operating temperature TS 1  of the light-emitting module  20  or not. When the process unit of the controlling module  50  determines that the first operating temperature T 1  is greater than or equal to the first critical operating temperature TS 1 , the process unit of the controlling module  50  will lower the output power of the power source module  40  to the light-emitting module  20  to stop temperatures of each light-emitting unit  22  of the light-emitting module  20  and each thermal sensitive element  41  of the power source module  40  from keeping rising. This is to effectively prevent the internal parts of the lamp  1  from being broken due to high temperatures. Therefore, a variety of thermal sensitive elements  41  of the power source module  40  could be effectively protected, especially the electrolyte of electrolytic capacitors could be prevented from leaking out due to the high temperature, and the product life of the light-emitting module  20  could be prolonged. The first thermal sensing element  51  could be a thermistor, a thermal diode or a thermal couple. In this embodiment, it could preferably be a positive temperature coefficient (PTC) thermistor, in which the resistance value and the ambient temperature are proportional. 
     Please refer to  FIG. 4 , regarding the aforementioned lamp cold zone A and lamp heat zone B, further said, the lamp cold zone A has a first cold zone boundary CB 1  and a second cold zone CB 2 ′; and the lamp heat zone B has a first heat zone boundary HB 1  and a second heat zone boundary HB 2 ′. The first heat zone boundary HB 1  is coplanar with a surface of the substrate  21  on which the light-emitting units  22  are disposed, the first cold zone boundary CB 1  is at the bottom of the conductive base  30 , and a distance between the first heat zone boundary HB 1  and the first cold zone boundary CB 1  is an internal element distance L. A distance (a second distance) between the second cold zone boundary CB 2 ′ and the first cold zone boundary CB 1  is one-third of the internal element distance L; and a distance (a first distance) between the second heat zone boundary HB 2 ′ and the first heat zone boundary HB 1  is one-third of the internal element distance L. In other words, the second cold zone boundary CB 2 ′ and the second heat zone boundary HB 2 ′ will be differ according to different lengths of the lamp  1  in practical applications. 
     Take the commonly used 18 W, conductive base  30 , E27 (or E26) A19 bulb for example, after use over a long time, the average temperature of the light-emitting module  20  is about 100° C. to 130° C. i.e. said lamp heat zone B, and the average temperature of the conductive base  30  is about 70° C. to 105° C., i.e. said lamp cold zone A. In other words, the temperature differences between the lamp heat zone B and the lamp cold zone A are up to 5 to 60 degrees, which means partial thermal sensitive element  41  disposed in the lamp heat zone B inside the LED bulb would be damaged due to high temperature after prolonged usage. Hence, the product life is relatively shortened. On the other hand, by disposing at least one first thermal sensing element  51  to determine internal operating temperatures of the lamp, by which the output power of the power source module  40  to the light-emitting module  20  is adjusted, prevents the light-emitting module  20  and each thermal sensitive element  41  from damage due to overheat. The following table shows experimental data of the actual temperatures of the instant disclosure and conventional lamp. It is shown that the lamp of the instant disclosure has lower operating temperature compared to the conventional one; this is to effectively protect each element inside the lamp from damage because of high temperatures. 
     
       
         
           
               
               
               
             
               
                   
               
               
                   
                 Conventional lamp 
                 Instant disclosure 
               
               
                   
               
             
            
               
                 Temperature of thermal 
                 110° C. 
                  90° C. 
               
               
                 sensitive element of 
                   
                   
               
               
                 power source module 
                   
                   
               
               
                 Substrate temperature of 
                 140° C. 
                 120° C. 
               
               
                 light-emitting module 
               
               
                   
               
            
           
         
       
     
     Please refer to  FIGS. 3 and 4 , it is noted that the plurality of heat dissipating channel  111  and the central channel  112  form an airflow pathway C; when lamp  1  is operating, the relatively cold air outside the lamp enters the central channel  112  in the lamp  1  through the heat dissipating channels  111  near the lamp heat zone B and flow away from the heat dissipating channels  111  adjacent to the lamp cold zone A because of the temperature differences between the lamp heat zone B and the lamp cold zone A. In other words, according to the disposition of the heat dissipating channels  111  and the central channel  112 , the external relatively cold air can flow through the lamp heat zone B of the lamp to help the lamp dissipate heat, thereby effectively protecting each element inside the lamp and preventing each element from damage due to high temperatures. 
     Second Embodiment 
     Please refer to  FIG. 5 , which is a diagram of a second embodiment of the instant disclosure. In the practical application, the first distance L 1  between the first heat zone boundary HB 1  and the second heat zone boundary HB 2  is within 0˜20 mm, and the second distance L 2  between the first cold zone boundary CB 1  and the second cold zone boundary CB 2  is within 0˜20 mm. In addition, the distance between the first heat zone boundary HB 1  and the substrate  21  of the light-emitting module  20  is 5˜7 mm. The said boundary range of 0˜20 mm is specifically for an E26 and E27 lamp; while the said boundary range could be determined according to sizes and lengths of lamps and not limited to the values provided by the instant disclosure. 
     Third Embodiment 
     Please refer to  FIG. 6 , which is a diagram of a third embodiment of the instant disclosure. The difference from the aforementioned embodiment is that the first heat zone boundary is defined by the position that is a safety distance D toward to the conductive base  30  from the surface of the substrate  21  of the light-emitting module  20  on which the light-emitting elements  22  are disposed to the first heat zone boundary HB 1 ′. The first cold zone boundary CB 1  is at the bottom of the conductive base  30 , and a distance between the first heat zone boundary HB 1 ′ and the first cold zone boundary CB 1 ′ is an internal element distance L′. A distance (a second distance) between the second cold zone boundary CB 2  and the first cold zone boundary CB 1  is one-third of the internal element distance L; and a distance (a first distance) between the second heat zone boundary HB 2 ′ and the first heat zone boundary HB 1  is one-third of the internal element distance L′. It is noted that the said safety distance is supposed to be 5˜7 mm when using E27 or E26 lamp bulbs. Other safety distances D of relative kinds of lamp are all well known to those skilled in the art, and will not be described in detail herein. 
     Fourth Embodiment 
     Please refer to  FIG. 7 , the significant difference between the present embodiment and aforementioned ones is that the controlling module  50  includes a first thermal sensing element  51 , a second thermal sensing element  52  and a processing unit (not shown). The position of the first thermal sensing element  51  is the same as the aforementioned one, and will not be described further; the second thermal sensing element  52  is disposed adjacently to the thermal sensitive element  41  of the power source module  40 , thereby measuring a second operating temperature TS 2  of the thermal sensitive element  41 . The processing unit of the controlling module  50  is electrically connected to the first thermal sensing element  51  and the second thermal sensing element  52 ; the processing unit of the controlling module  50  is able to determine whether the first operating temperature T 1  is greater than or equal to the first critical operating temperature TS 1  of the light-emitting module  20  and whether the second operating temperature T 2  is greater than or equal to a second critical operating temperature TS 2  of the thermal sensitive element  41 ; when the processing unit of the controlling module  50  judges that the first operating temperature T 1  is greater than or equal to the first critical operating temperature TS 1  or when the second operating temperature T 2  is greater than or equal to the second critical operating temperature TS 2 , the processing unit of the controlling module  50  lowers the output power of the power source module  40  to the light-emitting module  20 . 
     Specifically, when the lamp  1  is disposed in the relatively closed lampshade or space, the lamp  1  will be gradually heated under the long-term usage, therefore, the ambient temperature of the lampshade or the relatively closed space will be heated. That is, the temperature differences between the lamp cold zone A and the lamp heat zone B will be reduced. In other words, when the lamp  1  is disposed in the relatively closed lampshade or space, the temperature of the lamp cold zone A will be relatively high, and the thermal sensitive element  41  disposed in the lamp cold zone A will tend to be damaged due to the high temperature. Therefore, in the present embodiment, according to another exemplary aspect described, it could be the second thermal sensing element  52  disposed in the lamp  1  that monitors the second operating temperature T 2  of each thermal sensitive element  41  immediately, and effectively prevents the aforementioned problem from happening. In the preferable application, the first critical operating temperature TS 1  could be set to greater than the second critical operating temperature TS 2 . The following table shows experimental data of the actual temperatures of the instant disclosure and conventional lamp. It is shown that the instant disclosure can control the lamp to keep temperatures at relatively lower operating temperatures than conventional ones by disposing the thermal sensing element in the lamp heat zone; thereby every element in the lamp can be effectively protected. 
     
       
         
           
               
               
               
             
               
                   
               
               
                   
                 Conventional lamp 
                 Instant disclosure 
               
               
                   
               
             
            
               
                 Temperature of thermal 
                 115° C. 
                  93° C. 
               
               
                 sensitive element of 
                   
                   
               
               
                 power source module 
                   
                   
               
               
                 Substrate temperature of 
                 143° C. 
                 122° C. 
               
               
                 light-emitting module 
               
               
                   
               
            
           
         
       
     
     Fifth Embodiment 
     Please refer to  FIG. 8 , the significant difference between the present embodiment and aforementioned ones is that the controlling module  50  is disposed on the circuit board of the power source module  40  disposed in the lamp cold zone A, and at least one first thermal sensing element  51  of the controlling module  50  is disposed in the lamp heat zone B by way of jump wires. The said way of jump wires could utilize two stronger steel wires covered by insulating layer to connect the first thermal sensing element  51 . It is noted that, the figure of the present embodiment shows both the first thermal sensing element  51  and the second thermal sensing element  52 , however in the practical application, only the first thermal sensing element  51  could be disposed, and it is not limited to the figure. 
     Sixth Embodiment 
     Please refer to  FIG. 9 , the significant difference between the present embodiment and aforementioned ones is that the power source module  40  is disposed in the circuit board (such as, it could be an extending circuit board  42  extending toward the lamp heat zone B) of the lamp cold zone A, and the at least one first thermal sensing element  51  is disposed on the extending circuit board  42 , therefore the first thermal sensing element  51  is disposed steadily in the lamp heat zone B and the wires connected to each first thermal sensing element  51  are connected to the controlling module  50  through the extending circuit board  42 . In the practical application, it could be that the controlling module  50  and the at least one first thermal sensing element  51  thereof and the processing unit are disposed on the independent extending circuit board  42 , and the independent extending circuit board  42  is connected to the circuit board of the power source module  40 . It is noted that, the figure of the present embodiment shows both the first thermal sensing element  51  and the second thermal sensing element  52 , however in practical application, it could only be the first thermal sensing element  51  disposed, and it is not limited to the figure. 
     Seventh Embodiment 
     Please refer to  FIG. 10 , the significant difference between the present embodiment and aforementioned ones is that the outside of the power source module  40  is encapsulated by a sealant  60 , which could be insulating paste, thermally conductive paste or wax. In the practical application, the sealant  60  can be filled in the internal position of lamp  1  that corresponds to the power source module  40 . In the practical application, the power source module  40  is deposed in the hollow tube P 1  of the lamp  1 , the thermal sensitive element  41  of the power source module  40  is at the lamp cold zone A, and then the sealant  60  is filled in the spacing between the power source module  40  and the hollow tube P 1  by priming to completely cover the power source module  40 . That is, the heat produced by the power source module  40  could be rapidly transmitted to the hollow tube P 1  through the sealant  60 , and then be dissipated out through the heat dissipating fins  11 . On the other hand, the (most) heat produced by the light-emitting module  20  could be transmitted to the hollow tube P 1  through the sealant  60  before being transmitted to the power source module  40 . Hence the temperature surrounding the thermal sensitive element  41  of the power source module  40  could be relatively reduced. Briefly speaking, the present embodiment, by way of covering sealant  60  outside the power source module  40 , the heat produced by the power source module  40  can be transmitted rapidly as can the partial heat produced by the light-emitting module  20 , thereby the temperature surrounding the thermal sensitive element  41  of the power source module  40  is effectively reduced to achieve the aim of preventing the thermal sensitive element  41  from damage due to heat. 
     Eighth Embodiment 
     Please refer to  FIG. 11 , the significant difference between the present embodiment and aforementioned ones is, in the preferred application, in addition to the aforementioned sealant  60  encapsulating the outside of the power source module  40  to reduce the ambient temperature of the thermal sensitive element  41  of the power source module  40 , a thermal insulating element  70  (e.g. insulation cotton, heat resistant cotton, and insulation ceramics, etc.) is also disposed between the light-emitting module  20  and the sealant  60  of the power source module  40  to block the heat produced by the light-emitting module  20  from transmitting to the power source module  40 . In the practical application, it could be full of the thermal insulating element  70  around the light-emitting module  20  and the sealant  60  when using the thermal insulating element  70  such as insulating cotton. 
     It is noted that, please refer to  FIGS. 10 and 11 , the range of the sealant filled in the hollow tube P 1  could embrace the whole lamp cold zone A but exclude the lamp heat zone B; and the thermal insulating element  70  could be disposed between the lamp heat zone B and the sealant  60 , or fill the whole area not filled with the sealant  60 . 
     First Embodiment of the Method 
     Please refer to  FIG. 12 , which is a flow diagram of a thermal controlling method for lamps according to a first embodiment of the instant disclosure. As shown in  FIG. 12 , the thermal controlling method for lamps comprises following steps: 
     step S1: providing a lamp comprising a heat sink, a light-emitting module and a power supply module, wherein the heat sink comprises a plurality of heat dissipating fins spaced apart from each other, a heat dissipating channel is formed between each two of the plurality of heat dissipating fins, and the plurality of heat dissipating fins surround a central axis of the heat sink to form an accommodating space, the light-emitting module is disposed at one end of the heat sink; 
     step S2: disposing the power supply module into the accommodating space to form a central channel between the power supply module and the plurality of heat dissipating fins, wherein the central channel communicates with the heat dissipating channel, the power supply module comprises a controlling module and a power source module electrically connected to each other, the controlling module comprises at least one first thermal sensing element and a processing unit electrically connected to the power source module and the at least one first thermal sensing element, the power source module comprises at least one thermal sensitive element away from the light-emitting module and disposed in a lamp cold zone of the lamp; 
     step S3: disposing the at least one first thermal sensing element adjacent to a substrate of the light-emitting module to make the at least one first thermal sensing element in a lamp heat zone of the lamp; 
     step S4: operating the lamp; 
     step S5: determining whether a first operating temperature T 1  of the at least one first thermal sensing element is greater than or equal to a first critical operating temperature TS 1  of the light-emitting module by utilizing the processing unit; performing step 6 when the processing unit determines that the first operating temperature T 1  is greater than or equal to the first critical operating temperature TS 1 , otherwise, repeating performing the step 5; and 
     step S6: utilizing the processing unit to lower an output power of the power source module to the light-emitting module. 
     Wherein, the said first thermal sensing element is disposed in the lamp heat zone of the lamp, and for the definition regarding the boundaries of the lamp cold zone and the lamp heat zone refers to the aforementioned embodiments. The above mentioned first critical operating temperature could be the endurable maximum temperature of the light-emitting unit during operation; the practical application of the first critical operating temperature could be designed to be slightly lower than the highest temperature to prevent the light-emitting unit from damage. 
     Second Embodiment of the Method 
     Please refer to  FIG. 13 , which is a flow diagram of a thermal controlling method for lamps according to a second embodiment of the instant disclosure. The difference between the present embodiment and the aforementioned embodiment is that the controlling module  50  further comprises at least one second thermal sensing element, and the second sensing thermal sensing element is electrically connected to the second thermal sensing element. The present embodiment further comprises the following steps: (steps 1 to 3 are the same as the aforementioned embodiment): 
     step S31: disposing the at least one second thermal sensing element electrically connected to the processing unit in the lamp and adjacent to the at least one thermal sensitive element of the power source module of the lamp; 
     step S4: operating the lamp; 
     step S5: determining whether a first operating temperature T 1  of the at least one first thermal sensing element is greater than or equal to a first critical operating temperature TS 1  of the light-emitting module, or a second operating temperature T 2  of the at least one second thermal sensing element T 2  is greater than or equal to a second critical operating temperature TS 2  of the thermal sensitive element  41  by utilizing the processing unit; performing step 6 when the processing unit determines that the first operating temperature T 1  is greater than or equal to the first critical operating temperature TS 1 , or the second operating temperature is greater than or equal to the second critical operating temperature, otherwise, repeating performing the step 5; and 
     step S6: utilizing the processing unit to lower an output power of the power source module to the light-emitting module. 
     Wherein, the said first thermal sensing element and the said second thermal sensing element are disposed in the lamp heat zone and the lamp cold zone of the lamp, respectively, and for the definition regarding the boundaries of the lamp cold zone and the lamp heat zone refers to aforementioned embodiments. The above mentioned first critical operating temperature could be the endurable maximum temperature of the light-emitting unit during operating; the practical application of the first critical operating temperature could be designed to slightly lower than the highest temperature to prevent the light-emitting unit from damage. Different thermal sensitive elements can endure different maximum temperatures during operation, and the second critical operating temperature could be slightly lower than the minimal value among endurable maximum temperatures of each thermal sensitive element, and the second critical operating temperature could be designed according to each thermal sensitive element in the better exemplary embodiment. Specifically, in the better practical application, the additional first thermal sensing element and the second thermal sensing element could be disposed, therefore, even if one first thermal sensing element or one second thermal sensing element is damaged, the processing unit is still able to perform the determination of critical operating temperature according to other first thermal sensing elements or other second thermal sensing elements, which means that the processing unit determines the critical operating temperature according to the maximum temperature or the sub-maximum temperature among multiple first sensing elements (or second sensing elements). This is to prevent misjudging the temperature due to the damage of the thermal sensing elements. 
     Third Embodiment of the Method 
     Please refer to  FIG. 14 , which is a flow diagram of a thermal controlling method for lamps according to a third embodiment of the instant disclosure. The difference between the present embodiment and the aforementioned embodiment is that the present embodiment further comprises the following steps (steps 1 to 6 are the same as the aforementioned embodiment): 
     step S7: determining whether the output power of the power source module has been lowered or not, if not, then performing step S8; 
     step S71: determining whether the number of repetition of the step S6 exceeds a predetermined examination times or not, if it exceeds, then performing the step S72; otherwise performing the step S6; 
     step S72: stop operating the lamp; 
     step S8: repeating the step S5 and counting the number of repetitions of the step S5 according to a predetermined time; 
     step S81: determining whether the number of repetitions of the step S5 exceeds a predetermined operation times or not, if it exceeds, then performing the step S72. 
     Wherein, the steps S7 to S72 used to make sure the operation for lowering the output power of the power source module have been performed, thereby preventing the damage of lamps due to the damage of the processing unit or the power source module and the overheating of the lamp. In addition, preferably the said steps S7 to S72 could be performed by an independent detection module, such that the said problem of the controlling module or the power source module could be effectively prevented. 
     Regarding steps S8 to S81, they are to make sure the lamp would not be heated after lowering the output power. If the lamp keeps heating, then the lamp will be stop operating. More specifically, after the processing unit lowers the output power for a while, the light-emitting module is supposed to stop heating, however, if the substrate still keeping heating after several times of performing lowering the output power, this would mean that the lamp might be broken and unable controlling the heating. The lamp must stop operating at this time to prevent damage of the lamp. In addition to the said steps S7 to S72, which could be performed by another independent detection module, steps S8 to S81 repeats monitoring temperatures and adjusting power by managing their own controlling module. 
     The descriptions illustrated supra set forth simply the preferred embodiments of the instant disclosure; however, the characteristics of the instant disclosure are by no means restricted thereto. All changes, alterations, or modifications conveniently considered by those skilled in the art are deemed to be encompassed within the scope of the instant disclosure delineated by the following claims.