A temperature-controlled light source
Patent Information
- Application Number
- CN202522186473.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-16
- Publication Date
- 2026-09-22
- Estimated Expiration
- 2035-10-16
AI Technical Summary
然而，光源长时间工作会导致内部LED灯珠产生高热量，引起亮度衰减和寿命缩短
本实用新型提供的技术方案，与已知的公有技术相比，具有如下有益效果：
Smart Images
Figure CN224790819U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of industrial light source technology, specifically to a temperature-controlled light source. Background Technology
[0002] In industrial applications, light sources used for continuous inspection typically need to operate 24 / 7. However, prolonged operation leads to high heat generation in the internal LED chips, causing brightness decay and shortened lifespan. While some temperature control circuits are used in existing technologies, they mostly employ a single LED chip operating mode, failing to effectively address the heat accumulation problem. Therefore, a light source structure capable of automatically switching between LED groups and extending lifespan is needed. Utility Model Content
[0003] Technical problems to be solved In view of the above-mentioned shortcomings of the existing technology, this utility model provides a temperature-controlled light source, which aims to reduce the working temperature of individual light beads, extend the life of the light source and reduce brightness decay by dividing the lamp beads into two groups and integrating a temperature control circuit.
[0004] Technical solution To achieve the above objectives, this utility model provides the following technical solution: This invention provides a temperature-controlled light source, comprising a substrate and multiple light source points arrayed on the substrate. Each light source point consists of adjacent LED beads and LED beads. Multiple rows of LED beads form a first light group, with each row of LED beads connected in series with a current-limiting resistor R1. Multiple rows of LED beads form a second light group, with each row of LED beads connected in series with a current-limiting resistor R2. Thermistors RT1 and RT2 are respectively mounted on the current-limiting resistors R1 and R2. Thermistors RT1 and RT2 are respectively connected to the positive and negative input terminals of a comparator. The comparator controls the alternating conduction of the first and second light groups based on the resistance changes of the thermistors.
[0005] Furthermore, a transistor Q1 is connected in series with the first lamp group, and a transistor Q2 is connected in series with the second lamp group. The output terminal of the comparator is connected to the base of the transistors (Q1 and Q2) to control the conduction or cutoff of the first lamp group and the second lamp group, respectively.
[0006] Furthermore, the transistor Q1 of the first lamp group is a PNP type transistor, and the transistor Q2 of the second lamp group is an NPN type transistor. When the output of the comparator is high, the transistor Q2 is turned on, and the second lamp group is lit; when the output of the comparator is low, the transistor Q1 is turned on, and the first lamp group is lit.
[0007] Furthermore, the thermistors RT1 and RT2 are positive temperature coefficient thermistors, and at room temperature, the resistance of thermistor RT1 is greater than the resistance of thermistor RT2.
[0008] Furthermore, thermistors RT1 and RT2 are respectively connected in parallel with capacitors (C1, C2) for low-frequency filtering to smooth the temperature signal input to the comparator.
[0009] Furthermore, the thermistor RT1 is connected in series with the diode D1 and then connected to the positive input terminal of the comparator.
[0010] Furthermore, the thermistors (RT1, RT2) and the current-limiting resistors (R1, R2) are fixed together by thermal coupling bonding process.
[0011] Furthermore, the comparator employs a single-power-supply structure.
[0012] Beneficial effects The technical solution provided by this utility model has the following advantages compared with the known public technology: This invention utilizes a grouped LED chip and temperature control circuit design. By detecting the temperature rise of the current-limiting resistor using a thermistor, it eliminates the need for MCU control. Instead, a comparator circuit enables automatic alternation of operation between the first and second LED groups, effectively dispersing heat accumulation, extending the lifespan of the light sources, and maintaining brightness stability. The structure is simple, the cost is low, and it is suitable for large-scale industrial applications. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 This is a schematic diagram of the distribution structure of the light source LED beads of this utility model; Figure 2 This is a schematic diagram of the temperature control comparison circuit of this utility model; Figure 3 This is a diagram of the driving branch circuit for the first lamp group LED1 of this utility model; Figure 4 This is a diagram of the driving branch for the second lamp group LED12 of this utility model; The numbers in the diagram represent: 10, substrate; 11, LED bead one; 12, LED bead two. Detailed Implementation
[0015] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.
[0016] The present invention will be further described below with reference to the embodiments.
[0017] Example: This utility model provides a temperature-controlled adjustable light source, as shown in the reference. Figure 1-4 It includes a substrate 10 and multiple light source points arrayed on the substrate 10. Each light source point is composed of adjacent LED beads 11 and LED beads 12. Multiple rows of parallel LED beads 11 form a first lamp group LED1, and each row of LED beads 11 is connected in series with a current limiting resistor R1. Multiple rows of parallel LED beads 12 form a second lamp group LED2, and each row of LED beads 12 is connected in series with a current limiting resistor R2. In the driving branches of the first lamp group LED1 and the second lamp group LED2, they are respectively connected to the positive terminal VIN of the power supply, and respectively connected in series with a control switch and a corresponding current limiting resistor (R1, R2) to form a branch.
[0018] In the temperature control circuit that enables the alternating illumination of the first lamp group LED1 and the second lamp group LED2, firstly, thermistors RT1 and RT2 are respectively mounted on the current limiting resistors R1 and R2. Thermistors RT1 and RT2 are respectively connected to the positive and negative input terminals of the comparator. The comparator controls the alternating conduction of the first lamp group LED1 and the second lamp group LED2 according to the resistance change of the thermistors.
[0019] Specifically, the thermistors (RT1, RT2) and current-limiting resistors (R1, R2) are fixed together using a thermal coupling bonding process, allowing the thermistors (RT1, RT2) to accurately and in real-time sense the temperature rise of the current-limiting resistors. Simultaneously, the thermistor RT1, connected in parallel with capacitor C1, forms a temperature sampling circuit for the current-limiting resistor R1 in the first LED1 branch, connected to the positive input terminal (IN+) of the comparator; the thermistor RT2, connected in parallel with capacitor C2, forms a temperature sampling circuit for the current-limiting resistor R2 in the first LED2 branch, connected to the negative input terminal (IN-) of the comparator; capacitors (C1, C2) can be 0.1μF, used for low-frequency filtering to smooth the temperature signal input to the comparator.
[0020] Secondly, in this embodiment, the control switch in the first LED group LED1 branch uses transistor Q1, and the control switch in the second LED group LED2 branch uses transistor Q2. The output terminal (out+ / -) of the comparator is connected to the base of transistors (Q1, Q2). Specifically, in this embodiment, transistor Q1 of the first LED group LED1 is a PNP transistor, with its emitter connected to the positive terminal of the power supply and its collector connected to multiple rows of parallel LED beads 11. When the comparator outputs a low level, transistor Q1 conducts, and the first LED group LED1 lights up. Transistor Q2 of the second LED group LED2 is an NPN transistor, with its emitter grounded and its collector connected to multiple rows of parallel LED beads 12. When the comparator outputs a high level, transistor Q2 conducts, and the second LED group LED2 lights up.
[0021] In this embodiment, the comparator can be an LM393, and the comparator adopts a single power supply structure, that is, the comparator only uses one positive power supply VCC, and the output of the comparator directly drives the NPN and PNP transistors without level conversion. Preferably, thermistors RT1 and RT2 are positive temperature coefficient thermistors, and at room temperature, the resistance of thermistor RT1 is greater than the resistance of thermistor RT2.
[0022] In the control circuit, preferably, a diode D1 is connected in series with the thermistor RT1 and then connected to the positive input terminal of the comparator. The diode D1, with its fixed 0.7V forward voltage drop, applies a static bias voltage to the positive input terminal of the thermistor RT1, making its voltage slightly lower than the voltage at the negative input terminal. This ensures that the comparator output will not trigger when the thermistors (RT1 and RT2) have equal resistance values, but rather requires a certain resistance difference, thus creating a hysteresis characteristic.
[0023] The working principle of the temperature control circuit for this light source is as follows: In the initial state (room temperature), the resistance of thermistor RT1 is slightly greater than that of RT2, the voltage at the positive input terminal of the comparator is higher than that at the negative input terminal, and the output is high. At this time, the second lamp group LED2 is lit, and the first lamp group LED1 is in the off state.
[0024] As the second LED group (LED2) continues to operate, the current-limiting resistor R2 in its circuit heats up due to the current flowing through it, causing the resistance of RT2 mounted on it to rise. When the temperature rises to a set threshold (e.g., 60°C), the resistance of RT2 exceeds that of RT1, the voltage at the negative input terminal of the comparator is higher than that at the positive input terminal, and the output turns low. At this time, the second LED group (LED2) turns off, and the first LED group (LED1) lights up.
[0025] Subsequently, the first lamp group starts working and generates heat, and the resistance of RT1 gradually increases; at the same time, the second lamp group stops working, and the resistance of RT2 decreases as R2 cools down. When the resistance of RT1 exceeds that of RT2, the comparator flips again, illuminating the second lamp group once more. This cycle repeats continuously, enabling the two sets of lamps to work automatically and intermittently, effectively controlling the temperature rise of a single lamp group and extending the overall lifespan of the light source.
[0026] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of this utility model.
Claims
1. A temperature-controlled light source, comprising a substrate and a plurality of light source points arrayed on the substrate, characterized in that, Each light source point consists of adjacent LED beads 1 and LED beads 2. Multiple rows of LED beads 1 form a first lamp group, and each row of LED beads 1 is connected in series with a current-limiting resistor R1. Multiple rows of LED beads 2 form a second lamp group, and each row of LED beads 2 is connected in series with a current-limiting resistor R2. Thermistors RT1 and RT2 are respectively mounted on the current-limiting resistors R1 and R2. Thermistors RT1 and RT2 are respectively connected to the positive and negative input terminals of a comparator. The comparator controls the alternating conduction of the first lamp group and the second lamp group according to the resistance change of the thermistors.
2. The temperature-controlled adjustable light source according to claim 1, characterized in that, A transistor Q1 is connected in series with the first lamp group, and a transistor Q2 is connected in series with the second lamp group. The output of the comparator is connected to the base of the transistors (Q1 and Q2) to control the first lamp group and the second lamp group to be turned on or off, respectively.
3. A temperature-controlled adjustable light source according to claim 2, characterized in that, The transistor Q1 in the first lamp group is a PNP type transistor, and the transistor Q2 in the second lamp group is an NPN type transistor. When the output of the comparator is high, the transistor Q2 is turned on and the second lamp group is lit; when the output of the comparator is low, the transistor Q1 is turned on and the first lamp group is lit.
4. A temperature-controlled adjustable light source according to claim 3, characterized in that, The thermistors RT1 and RT2 are positive temperature coefficient thermistors, and at room temperature, the resistance of thermistor RT1 is greater than the resistance of thermistor RT2.
5. A temperature-controlled adjustable light source according to claim 4, characterized in that, Thermistors RT1 and RT2 are connected in parallel with capacitors (C1 and C2) for low-frequency filtering to smooth the temperature signal input to the comparator.
6. A temperature-controlled adjustable light source according to claim 2, characterized in that, The thermistor RT1 is connected in series with the diode D1 and then connected to the positive input terminal of the comparator.
7. A temperature-controlled adjustable light source according to claim 2, characterized in that, The thermistors (RT1, RT2) and the current-limiting resistors (R1, R2) are fixed together by thermal coupling bonding process.
8. A temperature-controlled adjustable light source according to claim 2, characterized in that, The comparator adopts a single-power supply structure.