Vehicle, vehicle-mounted lamp and temperature control circuit of vehicle-mounted lamp

Abstract

The utility model provides a vehicle, a vehicle-mounted lamp and a temperature control circuit of the vehicle-mounted lamp. In the temperature control circuit, the voltage across the two ends of the voltage stabilizing diode branch is broken down under the condition that the voltage across the two ends of the voltage stabilizing diode branch exceeds the overvoltage threshold of the voltage stabilizing diode branch, so that the voltage across the two ends of the voltage stabilizing diode branch does not fluctuate along with the fluctuation of the output voltage of the direct-current power supply; therefore, the potential, relative to the ground, of the output end of the temperature control circuit does not fluctuate along with the fluctuation of the output voltage. Therefore, the potential of the output end of the temperature control circuit relative to the ground does not fluctuate along with the fluctuation of the output voltage of the direct-current power supply within the fluctuation range of the output voltage, so that the brightness of the vehicle-mounted lamp does not fluctuate along with the fluctuation of the output voltage of the direct-current power supply. In addition, due to the fact that the number of components needed by the voltage stabilizing diode branch is small, and the structure is simple, the structure of the vehicle-mounted lamp adopting the temperature control circuit is optimized.

Description

Technical Field

[0001] The utility model relates to the technical field of temperature control circuits, in particular to a vehicle and a vehicle-mounted lamp and a temperature control circuit thereof. Background Art

[0002] With the vigorous promotion of new energy vehicles, the automotive lighting industry has also entered a period of vigorous development. Among them, automotive lighting refers to various lamps installed on vehicles for lighting and decoration, such as headlights, atmosphere lights, etc.

[0003] At present, the size of vehicle lamps has become smaller, which has increased the heat of the PCB board of the entire vehicle lamp. The current mainstream solution is to add a thermal derating function, that is, to add a temperature control circuit to the PCB board of the vehicle lamp. Since the DC voltage provided by the vehicle will fluctuate, LDO (low dropout linear regulator) is equipped in the mainstream temperature control circuit to prevent the potential of the output end of the temperature control circuit from fluctuating with the fluctuation of the DC voltage, that is, the brightness of the vehicle lamp does not fluctuate with the fluctuation of the DC voltage, thereby avoiding affecting driving safety. However, the structure of LDO is relatively complex and requires more components, which makes the structure of the temperature control circuit complex, and further makes the structure of the vehicle lamp complex.

[0004] Therefore, how to optimize the structure of vehicle-mounted lamps is a technical problem that needs to be solved urgently. Utility Model Content

[0005] In view of this, the utility model provides a vehicle, a vehicle-mounted lamp and a temperature control circuit thereof, so as to optimize the structure of the vehicle-mounted lamp.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] In a first aspect, the present application provides a temperature control circuit for a vehicle-mounted lamp, comprising: a voltage stabilizing diode branch and at least two first resistor branches; wherein:

[0008] All the first resistance branches are connected in series, one end of the series branch is connected to the output end of the DC power supply in the vehicle where the vehicle-mounted lamp is located, and the other end of the series branch is grounded;

[0009] The connection point of any two of the first resistance branches serves as the output end of the temperature control circuit;

[0010] The cathode of the voltage stabilizing diode branch is connected to the output end of the temperature control circuit, and the anode of the voltage stabilizing diode branch is grounded.

[0011] Optionally, the target voltage value is equal to the minimum value of the output voltage of the DC power supply when it fluctuates;

[0012] or,

[0013] The target voltage value is greater than a minimum value when the output voltage of the DC power supply fluctuates and is less than a maximum value when the output voltage of the DC power supply fluctuates;

[0014] The target voltage value is the value of the output voltage of the DC power supply when the voltage across the voltage stabilizing diode branch is equal to its own overvoltage threshold.

[0015] Optionally, it further includes: the thermistor branch; wherein:

[0016] Any one of the first resistance branches is connected in parallel with the thermistor branch;

[0017] or,

[0018] A branch formed by at least two adjacent first resistance branches is connected in parallel with the thermistor branch.

[0019] Optionally, the critical temperature of the temperature control circuit is respectively related to the temperature coefficient of the thermistor branch and the resistance value of each of the first resistance branches;

[0020] The critical temperature is a critical temperature at which the brightness of the vehicle-mounted lamp is reduced.

[0021] Optionally, one end of the thermistor branch is connected to the cathode of the zener diode branch, and the other end of the thermistor branch is connected to the anode of the zener diode branch.

[0022] Optionally, it further includes: a switch tube and a second resistance branch whose resistance is less than a first preset value; wherein:

[0023] The control end of the switch tube is connected to the low potential end of the thermistor branch;

[0024] The input end of the switch tube is connected to the output end of the temperature control circuit, and the output end of the switch tube is connected to the negative electrode of the output end of the DC power supply through the second resistance branch.

[0025] Optionally, if the first resistance branch connected in parallel with the thermistor branch is between the output end of the temperature control circuit and the ground, the resistance of the thermistor branch is negatively correlated with the temperature;

[0026] If the first resistance branch connected in parallel with the thermistor branch is between the output end of the DC power supply and the output end of the temperature control circuit, the resistance value of the thermistor branch is positively correlated with the temperature.

[0027] Optionally, it further includes: a third resistance branch whose resistance is less than the second preset value; wherein:

[0028] The low potential end of the series branch formed by all the first resistance branches is connected to one end of the third resistance branch, and the other end of the third resistance branch is connected to the ground.

[0029] Optionally, it further includes: a diode branch; wherein:

[0030] The connection point of any two of the first resistance branches is connected to the anode of the diode branch, and the cathode of the diode branch serves as the output end of the temperature control circuit.

[0031] A second aspect of the present application provides a vehicle-mounted lamp, comprising: a light-emitting device, a control device, and a temperature control circuit of the vehicle-mounted lamp as described in any one of the first aspects of the present application;

[0032] The output end of the temperature control circuit is connected to the receiving end of the control device, and the output end of the controller is connected to the light emitting device.

[0033] A third aspect of the present application provides a vehicle, comprising: a DC power supply and at least one vehicle-mounted lamp as described in the second aspect of the present application.

[0034] It can be seen from the above technical solution that the utility model provides a temperature control circuit for a vehicle-mounted lamp. In the temperature control circuit, when the voltage across the voltage-stabilizing diode branch exceeds its own overvoltage threshold, the voltage-stabilizing diode branch is broken down, that is, the voltage-stabilizing diode branch clamps the voltage across itself, so the voltage across the voltage-stabilizing diode branch will not fluctuate with the fluctuation of the output voltage of the DC power supply VCC; and because the cathode of the voltage-stabilizing diode branch is connected to the output end of the temperature control circuit and the anode of the voltage-stabilizing diode branch is grounded, in this case, the potential of the output end of the temperature control circuit relative to the ground will not fluctuate with the fluctuation of the above-mentioned output voltage, so that by reasonably setting the breakdown timing of the voltage-stabilizing diode branch, the potential of the output end of the temperature control circuit relative to the ground will not fluctuate with the fluctuation of the output voltage of the DC power supply VCC within the fluctuation range of the above-mentioned output voltage, so that the brightness of the vehicle-mounted lamp will not fluctuate with the fluctuation of the output voltage of the DC power supply VCC, that is, avoid affecting driving safety; in addition, since compared with LDO, the voltage-stabilizing diode branch requires fewer components and has a simpler structure, the temperature control circuit optimizes its own structure, so that the structure of the vehicle-mounted lamp using the temperature control circuit is optimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0036] Figure 1-Figure 10 Structural schematic diagrams of ten implementation modes of vehicles provided in the embodiments of the present application;

[0037] Fig.11 Schematic diagram of the relationship between the ratio of the power supply current of the vehicle lamp to the maximum current, the potential of the output end of the temperature control circuit 110 relative to the ground, and the power consumption of the thermistor branch 30;

[0038] Fig.12 A schematic structural diagram of an implementation of the control device 120. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] In this application, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0041] In order to optimize the structure of the vehicle lamp, the embodiment of the present application provides a temperature control circuit of the vehicle lamp. The specific structure can be found in Figure 1 , Figure 2 and Figure 3 110 in the circuit specifically includes: a voltage stabilizing diode branch 10 and at least two first resistor branches 20; the connection relationship between the components is specifically as follows:

[0042] All the first resistance branches 20 are connected in series, one end of the series branch is connected to the output end of the DC power supply VCC in the vehicle where the vehicle-mounted lamp is located, and the other end of the series branch is grounded GND; for example, Figure 1 or Figure 2 As shown, the temperature control circuit includes two first resistance branches 20, the two first resistance branches 20 are connected in series, one end of the series branch is connected to the output end of the DC power supply VCC, and the other end of the series branch is grounded GND; for example, Figure 3 As shown, the temperature control circuit includes three first resistance branches 20, and the three first resistance branches 20 are connected in series, one end of the series branch is connected to the output end of the DC power supply VCC, and the other end of the series branch is grounded GND.

[0043] The first resistance branch 20 includes at least one resistor. If the number of resistors is greater than 1, all resistors are connected in series and in parallel, and the two ends of the formed connection branch serve as the two ends of the first resistance branch 20 respectively; if the number of resistors is equal to, the two ends of the resistor serve as the two ends of the first resistance branch 20 respectively. For example, Figure 1 , Figure 2 or Figure 3 As shown in R1.

[0044] The connection point of any two first resistance branches 20 serves as the output terminal ADIM of the temperature control circuit. The output terminal ADIM of the temperature control circuit is connected to the receiving terminal of the control device in the vehicle lamp corresponding to the temperature control circuit. The output terminal of the control device supplies power to the light-emitting device in the vehicle lamp corresponding to the temperature control circuit. Specifically, the controller adjusts the brightness of the light-emitting device according to the potential of the output terminal ADIM of the temperature control circuit relative to the ground, thereby achieving brightness adjustment of the vehicle lamp. As for how the control device adjusts the brightness of the light-emitting device according to the potential of the output terminal ADIM of the temperature control circuit relative to the ground, it is already very mature in the prior art and will not be repeated here.

[0045] For example, Figure 1 , Figure 2 or Figure 3 As shown, from top to bottom, the connection point of the first two first resistance branches 2020 serves as the output terminal ADIM of the temperature control circuit.

[0046] The cathode of the voltage zener diode branch 10 is connected to the output terminal ADIM of the temperature control circuit, and the anode of the voltage zener diode branch 10 is grounded.

[0047] In a specific example, the voltage regulator diode branch 10 includes at least one unidirectional voltage regulator diode. If the number of unidirectional voltage regulator diodes is greater than 1, all unidirectional voltage regulator diodes are connected in series in the same direction, and the anode of the formed connecting branch serves as the anode of the voltage regulator diode branch 10, and the cathode of the formed connecting branch serves as the cathode of the voltage regulator diode branch 10; if the number of unidirectional voltage regulator diodes is equal to 1, the anode of the unidirectional voltage regulator diode serves as the anode of the voltage regulator diode branch 10, and the cathode of the unidirectional voltage regulator diode serves as the cathode of the voltage regulator diode branch 10, for example Figure 1 or Figure 3 As shown in TV1.

[0048] In another specific example, the voltage regulator diode branch 10 includes at least one bidirectional voltage regulator diode. If the number of bidirectional voltage regulator diodes is greater than 1, all the bidirectional voltage regulator diodes are connected in series, and the two ends of the formed connection branch serve as the anode and cathode of the voltage regulator diode branch 10 respectively; if the number of bidirectional voltage regulator diodes is equal to 1, the two ends of the bidirectional voltage regulator diode serve as the anode and cathode of the voltage regulator diode branch 10 respectively, for example Figure 2 As shown in TV2.

[0049] The above two examples only show two implementation methods of the voltage regulator diode branch 10. In practical applications, including but not limited to these, no specific limitation is made here and it can be determined according to the specific situation, all of which are within the protection scope of this application.

[0050] When the output voltage of the DC power supply VCC is equal to the target voltage value, the voltage across the Zener diode branch 10 is equal to its own overvoltage threshold value; when the output voltage of the DC power supply VCC is greater than the target voltage value, the voltage across the Zener diode branch 10 is greater than its own overvoltage threshold value, the Zener diode branch 10 is broken down, and the voltage across itself is clamped, that is, in this case, the voltage across the Zener diode will not fluctuate with the fluctuation of the output voltage of the DC power supply VCC; when the output voltage of the DC power supply VCC is less than the target voltage value, the voltage across the Zener diode branch 10 is less than its own overvoltage threshold value, the Zener diode branch 10 is not broken down, and the two ends of the Zener diode branch 10 are not clamped, that is, in this case, the voltage across the Zener diode fluctuates with the fluctuation of the output voltage of the DC power supply VCC.

[0051] In the temperature control circuit, when the voltage across the Zener diode branch 10 exceeds its own overvoltage threshold, the Zener diode branch 10 is broken down, that is, the Zener diode branch 10 clamps the voltage across itself, so the voltage across the Zener diode branch 10 will not fluctuate with the fluctuation of the output voltage of the DC power supply VCC; and because the cathode of the Zener diode branch 10 is connected to the output terminal ADIM of the temperature control circuit, and the anode of the Zener diode branch 10 is grounded, in this case, the potential of the output terminal ADIM of the temperature control circuit relative to the ground will not fluctuate with the fluctuation of the above-mentioned output voltage, thereby By reasonably setting the breakdown timing of the voltage-stabilizing diode branch 10, the potential of the output terminal ADIM of the temperature control circuit relative to the ground will not fluctuate with the fluctuation of the output voltage of the DC power supply VCC within the fluctuation range of the above-mentioned output voltage, thereby making the brightness of the vehicle lamps and lanterns not fluctuate with the fluctuation of the output voltage of the DC power supply VCC, thus avoiding affecting the driving safety; in addition, compared with LDO, the voltage-stabilizing diode branch 10 requires fewer components and has a simpler structure, so the temperature control circuit optimizes its own structure, thereby optimizing the structure of the vehicle lamps and lanterns using the temperature control circuit.

[0052] It can be seen from the connection relationship of the Zener diode branch 10 that the potential of the output terminal ADIM of the temperature control circuit relative to the ground is clamped to a value equal to the clamping voltage of the Zener diode branch 10, and the potential of the output terminal ADIM of the temperature control circuit relative to the ground is related to the brightness of the vehicle lamp, so the clamping voltage of the Zener diode branch 10 is determined according to the brightness that the vehicle lamp needs to maintain, that is, in the selection process of the diode branch, the clamping voltage of the Zener diode branch 10 is first determined according to the brightness that the vehicle lamp needs to maintain, and then the appropriate diode branch is selected according to the clamping voltage of the Zener diode branch 10; under normal circumstances, the brightness that the vehicle lamp needs to maintain is the maximum brightness of the vehicle lamp, that is, the appropriate diode branch is usually selected according to the maximum brightness of the vehicle lamp.

[0053] Another embodiment of the present application provides two other implementations of the temperature control circuit. The specific structures of these two implementations are the same as the above-mentioned implementations and will not be repeated here.

[0054] The first implementation mode is different from the above implementation modes in that: in this implementation mode, the target voltage value is equal to the minimum value of the output voltage of the DC power supply VCC when it fluctuates.

[0055] Among them, the target voltage value is the value of the output voltage of the DC power supply VCC when the voltage across the Zener diode branch 10 is equal to its own overvoltage threshold. In other words, when the output voltage of the DC power supply VCC is equal to the target voltage value, the voltage across the Zener diode branch 10 is equal to its own overvoltage threshold, that is, the Zener diode branch 10 is broken down.

[0056] In addition, the minimum value of the output voltage of the DC power supply VCC when it fluctuates refers to the minimum value within the fluctuation range of the output voltage of the DC power supply VCC. For example, if the output voltage of the DC power supply VCC fluctuates between 7V and 16V, then the fluctuation range of the output voltage of the DC power supply VCC is 7V to 16V, and the minimum value of the output voltage of the DC power supply VCC when it fluctuates is 7V.

[0057] Specifically, the target voltage value is equal to the minimum value of the output voltage of the DC power supply VCC when it fluctuates, indicating that when the output voltage of the DC power supply VCC is equal to the minimum value of its own fluctuation, the voltage across the Zener diode branch 10 is equal to its own overvoltage threshold.

[0058] Typically, the target voltage value can be adjusted by adjusting the number and distribution of the first resistance branches 20 .

[0059] Among them, adjusting the distribution of the first resistance branches 20 refers to: adjusting the number of first resistance branches 20 between the output end of the DC power supply VCC and the output end ADIM of the temperature control circuit, and the number of first resistance branches 20 between the output end ADIM of the temperature control circuit and the ground. In other words, adjusting the total resistance between the positive pole of the output end of the DC power supply VCC and the output end ADIM of the temperature control circuit, and the total resistance between the negative pole of the output end of the DC power supply VCC and the output end ADIM of the temperature control circuit.

[0060] It should be noted that how to adjust the number and distribution of the first resistance branches 20 is already very common to those skilled in the art and will not be described in detail here.

[0061] The second embodiment differs from the above embodiment in that: in this embodiment, the target voltage value is greater than the minimum value of the output voltage of the DC power supply VCC when it fluctuates and is less than the maximum value of the output voltage of the DC power supply VCC when it fluctuates.

[0062] Among them, the maximum value of the output voltage of the DC power supply VCC when it fluctuates refers to the maximum value within the fluctuation range of the output voltage of the DC power supply VCC. For example, if the output voltage of the DC power supply VCC fluctuates between 7V and 16V, then the fluctuation range of the output voltage of the DC power supply VCC is 7V to 16V, and the maximum value of the output voltage of the DC power supply VCC when it fluctuates is 16V.

[0063] It should be noted that the target voltage value has been described in detail above and will not be repeated here.

[0064] Specifically, the target voltage value is greater than the minimum value of the output voltage of the DC power supply VCC when it fluctuates and is less than the maximum value of the output voltage of the DC power supply VCC when it fluctuates, indicating that when the output voltage of the DC power supply VCC is equal to a value between the minimum value and the maximum value of its own fluctuation, the voltage across the Zener diode branch 10 is equal to its own overvoltage threshold.

[0065] It should be noted that the method for adjusting the target voltage value has been described in detail above and will not be repeated here.

[0066] In the first implementation mode provided in this embodiment, since the target voltage value is equal to the minimum value of the output voltage of the DC power supply VCC, the voltage regulator diode branch 10 is broken down within the entire fluctuation range of the output voltage of the DC power supply VCC, so that within the entire fluctuation range, the potential of the output terminal ADIM of the temperature control circuit relative to the ground will not fluctuate with the fluctuation of the above-mentioned output voltage, and further within the entire fluctuation range, the brightness of the vehicle lamp will not fluctuate with the fluctuation of the output voltage of the DC power supply VCCVCC.

[0067] In the second implementation mode provided in the present embodiment, since the target voltage value is greater than the minimum value when the output voltage of the DC power supply VCC fluctuates and is less than the maximum value when the output voltage of the DC power supply VCC fluctuates, the voltage regulator diode branch 10 can be broken down only within a part of the fluctuation range of the output voltage of the DC power supply VCC, so that only within this fluctuation range, the potential of the output terminal ADIM of the temperature control circuit relative to the ground will not fluctuate with the fluctuation of the above-mentioned output voltage, and further only within this fluctuation range, the brightness of the vehicle lamp will not fluctuate with the fluctuation of the output voltage of the DC power supply VCCVCC.

[0068] In addition, in the second implementation mode provided in the present embodiment, since the target voltage value is greater than the minimum value when the output voltage of the DC power supply VCC fluctuates and is less than the maximum value when the output voltage of the DC power supply VCC fluctuates, the voltage regulator diode branch 10 is not broken down within another part of the fluctuation range of the output voltage of the DC power supply VCC, so that within this fluctuation range, the potential of the output terminal ADIM of the temperature control circuit relative to the ground will fluctuate with the fluctuation of the above-mentioned output voltage, and further within this fluctuation range, the brightness of the vehicle lamp can fluctuate with the fluctuation of the output voltage of the DC power supply VCCVCC, so within this fluctuation range, the power of the vehicle lamp is reduced, thereby reducing the overall power of the vehicle lamp.

[0069] To sum up, the first implementation method provided in this embodiment can ensure driving safety to the greatest extent, while the second implementation method provided in this embodiment strikes a balance between ensuring driving safety and reducing the overall power consumption of the vehicle-mounted lamps, so that different directions can be emphasized in different situations, thereby taking both into account to a certain extent.

[0070] The present application embodiment provides another implementation of the temperature control circuit of the vehicle lamp. The specific structure thereof can be found in Figure 4 or Figure 5 110 in this embodiment, based on the above embodiment, further includes: a thermistor branch 30.

[0071] In a specific example, any first resistor branch 20 is connected in parallel with the thermistor branch 30; for example, Figure 4 As shown, the second first resistor branch 20 from the top to the bottom is connected in parallel with the thermistor branch 30; for another example, Figure 5 As shown, the first resistor branch 20 counted from the top to the bottom is connected in parallel with the thermistor branch 30 .

[0072] In another specific example, a branch formed by at least two adjacent first resistance branches 20 is connected in parallel with the thermistor branch 30 .

[0073] The above two examples only show two connection methods of the thermistor branch 30. In practical applications, including but not limited to these, no specific limitation is made here and it can be determined according to the specific situation, all of which are within the protection scope of this application.

[0074] Wherein, the thermistor branch 30 includes at least one resistor. If the number of thermistors is greater than 1, all the thermistors are connected in series and parallel, and the two ends of the formed connection branch serve as the two ends of the thermistor branch 30 respectively; if the number of thermistors is equal to, the two ends of the thermistor serve as the two ends of the thermistor branch 30 respectively, for example, Figure 4 As shown in Rz.

[0075] If the first resistor branch 20 connected in parallel with the thermistor branch 30 is between the output terminal ADIM of the temperature control circuit and the ground, for example, Figure 4 As shown, the resistance of the thermistor branch 30 is negatively correlated with the temperature.

[0076] If the first resistor branch 20 connected in parallel with the thermistor branch 30 is between the output end of the DC power supply VCC and the output end ADIM of the temperature control circuit, for example, Figure 5 As shown, the resistance of the thermistor branch 30 is positively correlated with the temperature.

[0077] Typically, the thermistor branch 30 is disposed in a vehicle-mounted lamp to detect the internal temperature of the vehicle-mounted lamp.

[0078] Taking the thermistor branch 30 whose resistance is negatively correlated with temperature as an example, the working principle of the temperature control circuit is described in detail:

[0079] When the temperature detected by the thermistor branch 30 is greater than its own critical temperature, the resistance of the thermistor branch 30 gradually decreases as the temperature rises. As the resistance of the thermistor branch 30 decreases, the total resistance between the output terminal ADIM of the temperature control circuit and the ground also gradually decreases.

[0080] If the voltage across the Zener diode branch 10 is less than its overvoltage threshold at this time, that is, the voltage across the Zener diode branch 10 is not clamped, then as the total resistance between the output terminal ADIM of the temperature control circuit and the ground gradually decreases, the potential of the output terminal ADIM of the temperature control circuit relative to the ground gradually decreases, thereby causing the brightness of the vehicle lamp to gradually decrease.

[0081] If at this time the voltage across the Zener diode branch 10 is greater than its overvoltage threshold, that is, the voltage across the Zener diode branch 10 is clamped, then as the total resistance between the output terminal ADIM of the temperature control circuit and the ground gradually decreases, the potential of the output terminal ADIM of the temperature control circuit relative to the ground will not gradually decrease; however, as the total resistance between the output terminal ADIM of the temperature control circuit and the ground gradually decreases, the voltage across the Zener diode branch 10 will be less than its overvoltage threshold at a certain moment, that is, the voltage across the Zener diode branch 10 is not clamped, and thereafter, as the total resistance between the output terminal ADIM of the temperature control circuit and the ground gradually decreases, the potential of the output terminal ADIM of the temperature control circuit relative to the ground will gradually decrease.

[0082] It should be noted that if the resistance of the thermistor branch 30 is positively correlated with the temperature, the working principle of the temperature control circuit is opposite to the above, which will not be described in detail here.

[0083] In practical applications, the critical temperature of the temperature control circuit is related to the temperature coefficient of the thermistor branch 30 and the resistance of each first resistor branch 20. In other words, by selecting a temperature coefficient with a suitable value and a first resistor branch 20 with a suitable resistance value, the critical temperature of the temperature control circuit can be adjusted to a required value.

[0084] The critical temperature is a critical temperature at which the brightness of the vehicle lamp is reduced.

[0085] This embodiment provides a specific connection method of the thermistor branch 30, which can be seen in Figure 4 , as follows:

[0086] One end of the thermistor branch 30 is connected to the cathode of the voltage-stabilizing diode branch 10, and the other end of the thermistor branch 30 is connected to the anode of the voltage-stabilizing diode branch 10. In other words, the thermistor branch 30 is connected in parallel with the voltage-stabilizing diode branch 10; for example, Figure 4 shown.

[0087] If the thermistor branch 30 is short-circuited, the thermistor branch 30 will short-circuit the voltage-stabilizing diode branch 10. At this time, the potential of the output terminal ADIM of the temperature control circuit relative to the ground is equal to the ground potential, that is, the vehicle lamp is off, that is, the brightness is zero.

[0088] Since the vehicle lamp will go out if the thermistor branch 30 is short-circuited, the temperature control circuit has a thermal protection function when the internal temperature of the vehicle lamp rises, thereby reducing the possibility of damage to the vehicle lamp due to the short circuit of the thermistor branch 30; in addition, a method for fault detection of the thermistor branch 30 is also provided, specifically: if it is found that the vehicle lamp is suddenly extinguished, the cause of the fault can be preliminarily determined to be a short circuit of the thermistor branch 30 in the temperature control circuit corresponding to the vehicle lamp.

[0089] The above is only a specific connection method of the thermistor branch 30. In practical applications, it includes but is not limited to this. No specific limitation is made here and it can be determined according to the specific situation. All of them are within the protection scope of this application.

[0090] Another embodiment of the present application provides another implementation of the temperature control circuit, which is applicable to the case where the connection method of the thermistor branch 30 adopts the connection method of the thermistor branch 30 provided in this embodiment; the specific structure of this implementation method can be seen in Figure 6 In 110, this embodiment, based on the above embodiment, further includes: a switch tube 40 and a second resistance branch 50 with a resistance value less than a first preset value.

[0091] Among them, the resistance of the second resistance branch 50 is less than the first preset value, which indicates that the resistance of the second resistance branch 50 is much smaller than the total resistance of the first resistance branch 20 between the two ends of the Zener diode branch 10; in actual applications, the first preset value can be set according to actual conditions.

[0092] The control end of the switch tube 40 is connected to the low potential end of the thermistor branch 30; the input end of the switch tube 40 is connected to the output end ADIM of the temperature control circuit, and the output end of the switch tube 40 is connected to the negative pole of the output end of the DC power supply VCC through the second resistor branch 50.

[0093] Optionally, the switch tube 40 may be a MOS tube or a triode, for example Figure 6As shown in Q, in practical applications, including but not limited to this, no specific limitation is made here, it may depend on the specific circumstances, and all are within the scope of protection of this application.

[0094] The second resistance branch 50 includes at least one resistor. If the number of resistors is greater than 1, all resistors are connected in series and in parallel, and the two ends of the formed connection branch serve as the two ends of the second resistance branch 50 respectively; if the number of resistors is equal to, the two ends of the resistor serve as the two ends of the second resistance branch 50 respectively. For example, Figure 6 As shown in R2.

[0095] When the thermistor branch 30 is short-circuited, the voltage-regulating diode branch 10 is short-circuited, and the current flows directly through the thermistor branch 30, then flows through the PN junction between the control end and the output end of the switch tube 40, and finally flows through the second resistor branch 50. It can be seen that the potential of the output terminal ADIM of the temperature control circuit is equal to the sum of the voltage of the PN junction between the control end and the output end of the switch tube 40 and the divided voltage of the second resistor branch 50.

[0096] Since the resistance of the second resistor branch 50 is much smaller than the total resistance of the first resistor branch 20 between the two ends of the Zener diode branch 10, the sum of the voltage of the PN junction between the control end and the output end of the switch tube 40 and the divided voltage of the second resistor branch 50 is much smaller than the voltage across the two ends of the Zener diode branch 10, so that the potential of the output end ADIM of the temperature control circuit relative to the ground is reduced, and then the brightness of the vehicle lamp is reduced; therefore, if the brightness of the vehicle lamp is suddenly reduced, the cause of the fault can be preliminarily determined to be a short circuit of the thermistor branch 30.

[0097] When the low potential end of the thermistor branch 30 is disconnected from the cathode of the Zener diode branch 10, the potential of the control end of the switch tube 40 is the anode voltage of the Zener diode branch 10, and the potential of the output end of the switch tube 40 is the cathode voltage of the Zener diode branch 10. If the voltage across the Zener diode branch 10 is greater than its own overvoltage threshold, the voltage between the control end and the output end of the switch tube 40 is equal to the clamping voltage of the Zener diode branch 10.

[0098] If the set value of the clamping voltage of the Zener diode branch 10 is greater than the turn-on threshold voltage of the switch tube 40, the switch tube 40 is turned on, and the current also flows through the switch tube 40 and the second resistor branch 50. Since the resistance of the second resistor branch 50 is much smaller than the total resistance of the first resistor branch 20 between the two ends of the Zener diode branch 10, if the voltage across the two ends of the Zener diode branch 10 is no longer greater than its overvoltage threshold, that is, the Zener diode branch 10 is no longer clamped, the potential of the output terminal ADIM of the temperature control circuit relative to the ground is reduced, that is, the brightness of the vehicle lamp is reduced. Therefore, if the brightness of the vehicle lamp is suddenly reduced, the cause of the fault can be preliminarily determined to be the disconnection between the low potential end of the thermistor branch 30 and the cathode of the Zener diode branch 10.

[0099] It should be noted that, in order to implement the above process, it is necessary to set the clamping voltage of the voltage stabilizing diode branch 10 to be greater than the turn-on threshold voltage of the switch tube 40 .

[0100] This embodiment also provides another implementation of the temperature control circuit. The specific structure can be found in Figure 7 110 in this implementation, based on the previous implementation provided in this embodiment, further includes: a fourth resistance branch 60 having a resistance value less than a third preset value.

[0101] Among them, the resistance of the fourth resistor branch 60 is less than the third preset value, which indicates that the resistance of the fourth resistor branch 60 is much smaller than the total resistance of the first resistor branch 20 between the two ends of the Zener diode branch 10; in actual applications, the third preset value can be set according to actual conditions.

[0102] In addition, the fourth resistance branch 60 includes at least one resistor. If the number of resistors is greater than 1, all resistors are connected in series and in parallel, and the two ends of the formed connection branch serve as the two ends of the fourth resistance branch 60 respectively; if the number of resistors is equal to, the two ends of the resistor serve as the two ends of the fourth resistance branch 60 respectively, for example, Figure 7 As shown in R4.

[0103] In the case where thermistor branch 30 is short-circuited, the process is the same as above and will not be repeated here.

[0104] When the connection between the low potential end of the thermistor branch 30 and the cathode of the Zener diode branch 10 is disconnected, the process is basically the same as above, except that: if the set value of the clamping voltage of the Zener diode branch 10 is greater than the turn-on threshold voltage of the switch tube 40, the switch tube 40 is turned on, and the current also flows through the switch tube 40 and the second resistor branch 50 and the fourth resistor branch 60. However, since the resistance of the fourth resistor branch 60 is much smaller than the total resistance of the first resistor branch 20 between the two ends of the Zener diode branch 10, it will not affect the subsequent derivation and will not be repeated here.

[0105] The above are only two implementation methods of the temperature control circuit, which are not specifically limited here and can be determined according to specific circumstances, and are all within the protection scope of this application.

[0106] Another embodiment of the present application provides another implementation of the temperature control circuit, and its specific structure can be found in Figure 8 or Fig. 9 110 in this embodiment, based on the above embodiment, further includes: a third resistance branch 70 with a resistance value less than the second preset value.

[0107] The low potential end of the series branch formed by all the first resistance branches 20 is connected to one end of the third resistance branch 70, and the other end of the third resistance branch 70 is connected to the ground.

[0108] Among them, the resistance of the third resistance branch 70 is less than the second preset value, indicating that: the resistance of the third resistance branch 70 is much smaller than the total resistance of all first resistance branches 20 between the output end ADIM of the temperature control circuit and the output end of the DC power supply VCC; in actual applications, the second preset value can be set according to actual conditions.

[0109] In addition, the third resistance branch 70 includes at least one resistor. If the number of resistors is greater than 1, all resistors are connected in series and in parallel, and the two ends of the formed connection branch serve as the two ends of the third resistance branch 70 respectively; if the number of resistors is equal to, the two ends of the resistor serve as the two ends of the third resistance branch 70 respectively, for example, Figure 8 or Fig. 9 As shown in R3.

[0110] Since the resistance of the third resistance branch 70 is much smaller than the total resistance of all the first resistance branches 20 between the output terminal ADIM of the temperature control circuit and the output terminal of the DC power supply VCC, its voltage is very small and can be ignored, so that this voltage does not affect the potential of the output terminal ADIM of the temperature control circuit relative to the ground.

[0111] In addition, in this embodiment, without including the switch tube 40, the second resistor branch 50 and the fourth resistor branch 60, if the thermistor branch 30 is short-circuited, the thermistor branch 30 will short-circuit the voltage-stabilizing diode branch 10. At this time, the potential of the output terminal ADIM of the temperature control circuit relative to the ground is equal to the divided voltage of the third resistor branch 70; since the resistance of the third resistor branch 70 is much smaller than the total resistance of all the first resistor branches 20 between the output terminal ADIM of the temperature control circuit and the output terminal of the DC power supply VCC, the potential of the output terminal ADIM of the temperature control circuit relative to the ground is equal to close to zero but not equal to zero.

[0112] In this embodiment, by adding the third resistor branch 70, the possibility that the voltage-stabilizing resistor branch cannot work normally is reduced, thereby improving the reliability of the temperature control circuit.

[0113] This embodiment also provides another implementation of the temperature control circuit. The specific structure can be found in Fig.10 110 in this embodiment, based on the above embodiment, further includes: a diode branch 80.

[0114] The diode branch 80 includes at least one diode. If the number of diodes is greater than 1, all diodes are connected in series in the same direction, and the anode of the series branch formed is used as the anode of the diode branch 80, and the cathode of the series branch formed is used as the cathode of the diode branch 80; if the number of diodes is equal to 1, the anode of the diode is used as the anode of the diode branch 80, and the cathode of the diode is used as the cathode of the diode branch 80. For example, Fig.10 As shown in Z.

[0115] Due to the addition of the diode branch 80, compared with the above embodiment, the potential of the output terminal ADIM of the temperature control circuit in this embodiment relative to the ground reduces the conduction voltage drop of the diode branch 80. Therefore, by adjusting the conduction voltage drop of the diode branch 80, the potential of the output terminal ADIM of the temperature control circuit relative to the ground can be adjusted.

[0116] The above are only two implementation methods of the temperature control circuit, which are not specifically limited here and can be determined according to specific circumstances, and are all within the protection scope of this application.

[0117] by Fig. 9 Taking 110 in FIG. 1 as an example, assuming that the resistance of the first first resistor branch 20 from top to bottom is 4.8kΩ, the resistance of the second first resistor branch 20 is 2.2kΩ, the resistance of the third resistor branch 70 is 700Ω, the clamping voltage of the voltage regulator diode branch 10 is 3.3V, the resistance of the thermistor branch 30 is 100kΩ, and the output voltage of the DC power supply VCC fluctuates between 7 and 16V; in addition, assuming that the output terminal of the temperature control circuit 110 can reach a potential of 3V relative to the ground, the vehicle-mounted lamp can reach maximum brightness.

[0118] When the output voltage of the DC power supply VCC is 7V, the potential of the output end of the temperature control circuit 110 relative to the ground is approximately 2.5V, and the power supply current of the vehicle lamp is approximately 80% of the maximum current, that is, the brightness of the vehicle lamp is approximately 80% of the maximum brightness; when the output voltage of the DC power supply VCC is 11V, the potential of the output end of the temperature control circuit 110 relative to the ground is approximately 3V, and the power supply current of the vehicle lamp is approximately 100% of the maximum current, and the power supply current of the vehicle lamp is approximately 100% of the maximum current; when the output voltage of the DC power supply VCC is 13.5V, the potential of the output end of the temperature control circuit 110 relative to the ground is approximately 3.18V; when the output voltage of the DC power supply VCC is 16V, the potential of the output end of the temperature control circuit 110 relative to the ground is approximately 3.3V, and the power supply current of the vehicle lamp is approximately 100% of the maximum current, that is, the brightness of the vehicle lamp is approximately 100% of the maximum brightness.

[0119] The relationship between the ratio of the power supply current to the maximum current of the vehicle lamp, the potential of the output terminal of the temperature control circuit 110 relative to the ground, and the power consumption of the thermistor branch 30 is obtained by simulation test. Fig.11 As shown; Fig.11 Wherein VADIM is the potential of the output terminal of the temperature control circuit 110 relative to the ground, P is the power consumption of the thermistor branch 30, and I_LED% is the ratio of the power supply current of the vehicle lamp to the maximum current.

[0120] If the thermistor branch 30 is short-circuited, the thermistor branch 30 will short-circuit the voltage-stabilizing diode branch 10. At this time, the potential of the output terminal ADIM of the temperature control circuit relative to the ground is equal to the divided voltage of the third resistor branch 70; and the divided voltage of the third resistor branch 70 = the output voltage of the DC power supply VCC × the resistance of the third resistor branch 70 ÷ (the resistance of the first first resistor branch 20 + the resistance of the second first resistor branch 20); when the output voltage of the DC power supply VCC is 13.5V, the potential of the output terminal of the temperature control circuit 110 relative to the ground is approximately 1.72V, and the power supply current of the vehicle lamp is approximately 60% of the maximum current, that is, the brightness of the vehicle lamp is approximately 60% of the maximum brightness. Therefore, if the brightness of the vehicle lamp suddenly decreases, the cause of the fault can be preliminarily determined to be the short circuit of the thermistor branch 30 in the temperature control circuit corresponding to the vehicle lamp.

[0121] by Fig.10 Take 110 as an example, Fig.10 Zhongyu Fig. 9 The setting values ​​of the same components are the same as above and are not repeated here. In addition, it is assumed that the resistance value of the second resistance branch 50 is 10Ω and the resistance value of the fourth resistance branch 60 is 100Ω.

[0122] If the thermistor branch 30 is short-circuited, the voltage-stabilizing diode branch 10 is short-circuited, and the current flows directly through the thermistor branch 30, and then flows through the PN junction between the control end and the output end of the switch tube 40, and finally flows through the second resistor branch 50. At this time, the potential of the output terminal ADIM of the temperature control circuit relative to the ground is equal to the sum of the voltage of the PN junction between the control end and the output end of the switch tube 40 and the divided voltage of the second resistor branch 50, which is approximately 0.8V. At this time, the power supply current of the vehicle lamp approximately reaches 30% of the maximum current, that is, the brightness of the vehicle lamp approximately reaches 30% of the maximum brightness. Therefore, if the brightness of the vehicle lamp suddenly decreases, the cause of the fault can be preliminarily determined to be the short circuit of the thermistor branch 30 in the temperature control circuit corresponding to the vehicle lamp.

[0123] If the low potential end of the thermistor branch 30 is disconnected from the cathode of the Zener diode branch 10, the potential of the control end of the switch tube 40 is the anode voltage of the Zener diode branch 10, and the potential of the output end of the switch tube 40 is the cathode voltage of the Zener diode branch 10; if the voltage across the Zener diode branch 10 is greater than its own overvoltage threshold, the voltage between the control end and the output end of the switch tube 40 is equal to the clamping voltage of the Zener diode branch 10.

[0124] Assuming that the set value of the clamping voltage of the Zener diode branch 10 is greater than the conduction threshold voltage of the switch tube 40, the switch tube 40 is turned on, and the current also flows through the switch tube 40 and the second resistor branch 50. Since the resistance of the second resistor branch 50 is much smaller than the total resistance of the first resistor branch 20 between the two ends of the Zener diode branch 10, if the voltage across the two ends of the Zener diode branch 10 is no longer greater than its overvoltage threshold, that is, the Zener diode branch 10 is no longer clamped, the potential of the output terminal ADIM of the temperature control circuit relative to the ground is approximately 2.2V. At this time, the power supply current of the vehicle lamp approximately reaches 76% of the maximum current, that is, the brightness of the vehicle lamp approximately reaches 76% of the maximum brightness. Therefore, if the brightness of the vehicle lamp suddenly decreases, the cause of the fault can be preliminarily determined to be the disconnection between the low potential end of the thermistor branch 30 and the cathode of the Zener diode branch 10.

[0125] Another embodiment of the present application provides a vehicle-mounted lamp, the specific structure of which can be seen in Figure 1-Figure 9 100 in the figure specifically includes: a temperature control circuit 110, a control device 120 and a light emitting device 130 of the vehicle lamp as provided in the above embodiment.

[0126] The output end of the temperature control circuit 110 is connected to the receiving end of the control device 120 , and the output end of the controller is connected to the light emitting device 130 .

[0127] Optionally, the light emitting device 130 is an LED lamp. In practical applications, including but not limited to this, no specific limitation is made here and it can be determined according to specific circumstances, all of which are within the scope of protection of this application.

[0128] It should be noted that the temperature control circuit 110 and the control device 120 have been described in detail above and will not be repeated here. The specific structure of the control device 120 can be as follows: Fig.12 As shown, since it is very mature in the prior art, it will not be described here.

[0129] Another embodiment of the present application provides a vehicle, the specific structure of which can be seen in Figure 1-Figure 9 , specifically comprising: a DC power supply VCC and at least one vehicle lamp 100 provided in the above embodiment.

[0130] Optionally, the vehicle-mounted lamp 100 may be a headlamp or a taillamp, or an ambient light. In practical applications, this includes but is not limited to these. No specific limitation is made here and it may be determined according to specific circumstances, all of which are within the scope of protection of this application.

[0131] It should be noted that the connection relationship between the DC power supply VCC and the vehicle-mounted lamp 100 has been described in detail above and will not be repeated here.

[0132] For the above description of the disclosed embodiments, the features recorded in each embodiment in this specification can be replaced or combined with each other, so that professional and technical personnel in this field can implement or use this application. The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form. Although the utility model has been disclosed as above with a preferred embodiment, it is not used to limit the utility model. Any technician familiar with the field can make many possible changes and modifications to the technical solution of the utility model by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the utility model, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the utility model without departing from the content of the technical solution of the utility model still falls within the scope of protection of the technical solution of the utility model.

Claims

1. A temperature control circuit for a vehicle lamp, characterized in that: include: A voltage stabilizing diode branch and at least two first resistor branches; wherein: All the first resistance branches are connected in series, one end of the series branch is connected to the output end of the DC power supply in the vehicle where the vehicle-mounted lamp is located, and the other end of the series branch is grounded; The connection point of any two of the first resistance branches serves as the output end of the temperature control circuit; The cathode of the voltage stabilizing diode branch is connected to the output end of the temperature control circuit, and the anode of the voltage stabilizing diode branch is grounded.

2. The temperature control circuit of the vehicle lamp according to claim 1, characterized in that: The target voltage value is equal to the minimum value of the output voltage of the DC power supply when it fluctuates; or, The target voltage value is greater than a minimum value when the output voltage of the DC power supply fluctuates and is less than a maximum value when the output voltage of the DC power supply fluctuates; The target voltage value is the value of the output voltage of the DC power supply when the voltage across the voltage stabilizing diode branch is equal to its own overvoltage threshold.

3. The temperature control circuit of the vehicle lamp according to claim 1, characterized in that: Also includes: Thermistor branch; where: Any one of the first resistance branches is connected in parallel with the thermistor branch; or, A branch formed by at least two adjacent first resistance branches is connected in parallel with the thermistor branch.

4. The temperature control circuit of the vehicle lamp according to claim 3, characterized in that: The critical temperature of the temperature control circuit is respectively related to the temperature coefficient of the thermistor branch and the resistance value of each of the first resistance branches; The critical temperature is a critical temperature at which the brightness of the vehicle-mounted lamp is reduced.

5. The temperature control circuit of the vehicle lamp according to claim 3, characterized in that: One end of the thermistor branch is connected to the cathode of the voltage stabilizing diode branch, and the other end of the thermistor branch is connected to the anode of the voltage stabilizing diode branch.

6. The temperature control circuit of the vehicle lamp according to claim 5, characterized in that: Also includes: A switch tube and a second resistance branch with a resistance value less than a first preset value; wherein: The control end of the switch tube is connected to the low potential end of the thermistor branch; The input end of the switch tube is connected to the output end of the temperature control circuit, and the output end of the switch tube is connected to the negative electrode of the output end of the DC power supply through the second resistance branch.

7. The temperature control circuit of the vehicle lamp according to claim 3, characterized in that: If the first resistor branch connected in parallel with the thermistor branch is between the output end of the temperature control circuit and the ground, the resistance of the thermistor branch is negatively correlated with the temperature; If the first resistance branch connected in parallel with the thermistor branch is between the output end of the DC power supply and the output end of the temperature control circuit, the resistance value of the thermistor branch is positively correlated with the temperature.

8. The temperature control circuit of the vehicle lamp according to any one of claims 1 to 6, characterized in that: Also includes: A third resistor branch having a resistance value less than a second preset value; wherein: The low potential end of the series branch formed by all the first resistance branches is connected to one end of the third resistance branch, and the other end of the third resistance branch is connected to the ground.

9. The temperature control circuit of the vehicle lamp according to any one of claims 1 to 6, characterized in that: Also includes: Diode branch; where: The connection point of any two of the first resistance branches is connected to the anode of the diode branch, and the cathode of the diode branch serves as the output end of the temperature control circuit.

10. A vehicle-mounted lamp, characterized in that: include: A light emitting device, a control device and a temperature control circuit of a vehicle-mounted lamp as claimed in any one of claims 1 to 9; The output end of the temperature control circuit is connected to the receiving end of the control device, and the output end of the controller is connected to the light emitting device.

11. A vehicle, characterized in that: include: A direct current power source and at least one vehicle-mounted lamp as claimed in claim 10.

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