Lamplight color temperature adjusting circuit and lighting apparatus

Abstract

Disclosed in the present invention are a lamplight color temperature adjusting circuit and a lighting apparatus. The lamplight color temperature adjusting circuit comprises a main control module, a first dimming unit, a second dimming unit, and a compensation unit, wherein the first dimming unit is electrically connected to the main control module and is configured to drive a high-color-temperature light source; the second dimming unit is electrically connected to the main control module and is configured to drive a low-color-temperature light source for light mixing with the high-color-temperature light source; and the compensation unit comprises a first compensation driving module, which is electrically connected to the main control module and, on the basis of a control signal from the main control module, controls a compensation light source to perform color temperature compensation. By means of controlling the compensation unit to separately drive and adjust the compensation light source, the lamplight color temperature adjusting circuit of the present embodiment compensates for a color temperature after light from the high-color-temperature light source and light from the low-color-temperature light source are combined, so that the color temperature coordinates after light combination fall on a blackbody locus, reducing color tolerance and improving light quality.

Description

Light color temperature adjustment circuit and lighting device Technical Field

[0001] The present invention relates to the technical field of lighting devices, and in particular to a light color temperature adjustment circuit and a lighting device. Background Art

[0002] Color temperature is a physical quantity used to describe the color of a light source. It refers to the temperature of a light source with the same color as a blackbody radiation, and is measured in Kelvin (K). A blackbody is an ideal object that absorbs all incident light and emits thermal radiation in proportion to its own temperature. As the temperature increases, the color of a blackbody changes from red to yellow, then to white, and finally to blue. The higher the color temperature, the closer the color of the light source is to white or blue, while the lower the color temperature, the closer the color is to red or yellow. For example, the surface temperature of the sun is approximately 6000K, making it closer to white, while the temperature of candlelight is approximately 2000K, making it closer to yellow.

[0003] Color temperature adjustment is a common optical technology used to change the color of a light source to suit different environments and needs. Currently, a common approach involves connecting the outputs of two DC / DC constant current circuits to a high- and low-color-temperature light source, respectively. Using PWM (pulse-width modulation) to adjust the brightness of the two colors, the color temperature is adjusted by combining the two colors. This approach offers the advantages of continuous color temperature variation, a simple circuit structure, and low cost.

[0004] However, this solution has its shortcomings. Since the color temperature is adjusted by combining high color temperature light sources and low color temperature light sources, the color temperature curve is a straight line. The color temperature curve and the blackbody trajectory have only two intersection points. The color coordinates of other points will deviate from the blackbody trajectory, and the color tolerance is not zero, resulting in large differences in light source color.

[0005] Summary of the Invention

[0006] The main purpose of the present invention is to provide a light color temperature adjustment circuit to solve the problem of large color differences of light sources.

[0007] To achieve the above object, the present invention provides a light color temperature adjustment circuit, which includes:

[0008] Main control module;

[0009] a first dimming unit, electrically connected to the main control module, for driving a high color temperature light source;

[0010] a second dimming unit, electrically connected to the main control module, for driving the low color temperature light source to mix light with the high color temperature light source;

[0011] The compensation unit includes a first compensation driving module, which is electrically connected to the main control module and controls the compensation light source to perform color temperature compensation according to a control signal from the main control module.

[0012] In some embodiments, the first dimming unit includes a first driving module and a cool white lamp group, and the first driving module is electrically connected to the cool white lamp group and the main control module; the second dimming unit includes a second driving module and a warm white lamp group, and the second driving module is electrically connected to the warm white lamp group and the main control module; the compensation unit also includes a first compensation lamp group, and the first compensation lamp group is electrically connected to the first compensation driving module.

[0013] In some embodiments, the first compensation lamp group is a red light group.

[0014] In some embodiments, the color temperature of the cool white light group is 7000K-8500K, the color temperature of the warm white light group is 1500K-2500K, and the wavelength of the red light group is 635nm-670nm.

[0015] In some embodiments, the compensation unit further includes a second compensation driving module and a second compensation lamp group, the second compensation driving module is electrically connected to the main control module and the second compensation lamp group, and the second compensation module drives and adjusts the second compensation lamp group according to the control signal of the main control module.

[0016] In some embodiments, the second compensation light group is a green light group.

[0017] In some embodiments, the first driving module, the second driving module, the first compensation driving module, and the second compensation driving module each include:

[0018] an energy storage circuit electrically connected to the external DC power supply and the lamp assembly for storing or releasing electrical energy;

[0019] a control module, electrically connected to the main control module and configured to receive a control signal from the main control module;

[0020] The sampling control circuit is electrically connected to the output end of the control module, and the collection end of the sampling control circuit is electrically connected to the energy storage circuit for collecting the current of the energy storage circuit.

[0021] In some embodiments, the sampling control circuit includes:

[0022] a switch tube, a conducting end of which is electrically connected to the energy storage circuit;

[0023] A current sampling module is electrically connected to the other conducting end of the switch tube;

[0024] A current comparator is electrically connected to the control module, an input end of the current comparator is electrically connected to the current sampling module, and an output end is electrically connected to the gate of the switch tube, for controlling the conduction or disconnection of the switch tube.

[0025] In some embodiments, the sampling control circuit further includes:

[0026] The lamp group current sampling module has an output end electrically connected to the current comparator and a collection end electrically connected to the negative electrode of the lamp group.

[0027] The present invention further provides a lighting device including the aforementioned light color temperature adjustment circuit.

[0028] The beneficial effects of the technical solution of the present invention are as follows: a first dimming unit is electrically connected to the main control module to drive and adjust the high color temperature light source, a second dimming unit is electrically connected to the main control module to drive and adjust the low color temperature light source to combine with the high color temperature light source, and finally, a compensation unit is electrically connected to the main control module to drive and adjust the compensation light source to compensate for the color temperature of the combined light source. Compared to existing solutions that use two-color light combination to adjust color temperature, the light color temperature adjustment circuit of this embodiment controls the compensation unit to drive and adjust the compensation light source alone, compensating the color temperature of the combined high and low color temperature light sources, so that the color temperature coordinates of the combined light source fall on the blackbody locus, reducing color tolerance and improving light quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a schematic diagram of the electrical connection of modules of an embodiment of a light color temperature adjustment circuit according to the present invention;

[0030] FIG2 is a schematic diagram of electrical connections of modules of another embodiment of a light color temperature adjustment circuit according to the present invention;

[0031] FIG3 is a driving circuit diagram of another embodiment of the light color temperature adjustment circuit of the present invention;

[0032] FIG4 is a driving circuit diagram of another embodiment of the light color temperature adjustment circuit of the present invention.

[0033] Description of the accompanying figures: 100, main control module; 110, first dimming unit; 111, first driving module; 112, cool white lamp group; 120, second dimming unit; 121, second driving module; 122, warm white lamp group; 130, compensation unit; 131, first compensation driving module; 132, red light group; 133, second compensation driving module; 134, green light group; 200, energy storage circuit; 210, control module; 210a, output end of the control module; 220, sampling Control circuit; 220a, collection end of sampling control circuit; Q1, switch tube; S1, one conduction end of switch tube; D1, the other conduction end of switch tube; G, gate of switch tube; 221, current sampling module; 222, current comparator; 222a, one input end of current comparator; 222b, output end of current comparator; 223, lamp group current sampling module; 223a, output end of lamp group current sampling module; 223b, collection end of lamp group current sampling module.

[0034] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0035] The following will be combined with the accompanying drawings to clearly and completely describe the solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0036] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0037] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element.

[0038] In addition, the descriptions of "first", "second", etc. in the present invention are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] Different color temperatures have different effects on mood and vision. Generally speaking, warm light can create a sense of warmth, comfort, and ease, and is suitable for homes, residences, dormitories, hotels, and other places with relatively low temperatures. Cool light can create a sense of brightness, clarity, and energy, and is suitable for offices, study rooms, reading rooms, exhibition halls, and other places with relatively high temperatures. This invention proposes a light color temperature adjustment circuit, primarily used for color temperature compensation of LED lights, such as correcting the coordinates of mixed colors at high and low color temperatures, thereby compensating for and reducing color tolerance in lighting devices.

[0040] As shown in FIG1 and FIG2 , the light color temperature adjustment circuit proposed in the present invention includes a main control module 100 , a first dimming unit 110 , a second dimming unit 120 and a compensation unit 130 , wherein:

[0041] The first dimming unit 110 is electrically connected to the main control module 100 and is used to drive and adjust the high color temperature light source;

[0042] The second dimming unit 120 is electrically connected to the main control module 100 and is used to drive and adjust the low color temperature light source to mix with the high color temperature light source;

[0043] The compensation unit 130 includes a first compensation driver module 131, which is electrically connected to the main control module 100 and controls the compensation light source to perform color temperature compensation based on control signals from the main control module 100. It should be noted that in this embodiment, the first compensation driver module 131 uses an LED boost constant current circuit. In other embodiments, an LED buck constant current circuit may be used, and this is not particularly limited here.

[0044] During operation, the light color temperature adjustment circuit of this embodiment (using the operating principle of an LED boost constant current circuit as an example) is a power conversion circuit that boosts input voltage to output voltage. It operates by utilizing the energy storage and release characteristics of an inductor, switching the switch Q1 on and off to achieve conversion between input and output voltages. Its advantages include providing a constant current to the LED, ensuring LED brightness and lifespan, high efficiency, and a simple circuit.

[0045] It's important to note that the LED boost circuit consists of a switch Q1, an inductor, a diode, an output filter capacitor, a sampling resistor, an integrated circuit, and a load (i.e., an LED light cluster). The control terminal of switch Q1 requires a PWM signal to control its on and off states. Its operating state is divided into two phases: on and off.

[0046] In the conduction stage, the switch tube Q1 is turned on, which is equivalent to a short circuit. The input voltage charges the inductor, and the voltage across the inductor is the input voltage. The current on the inductor increases linearly, and the diode is cut off, which is equivalent to an open circuit. The output filter capacitor discharges to the load, and the output voltage decreases linearly. At this time, the brightness of the LED lamp decreases.

[0047] In the cut-off stage, the switch tube Q1 is cut off, which is equivalent to an open circuit. The inductor discharges, and the voltage across the inductor is the output voltage minus the input voltage minus the diode voltage drop. The current on the inductor decreases linearly, and the diode is turned on, which is equivalent to a short circuit. The inductor and the input voltage jointly charge the output filter capacitor and the load, and the output voltage increases linearly, and the brightness of the LED lamp increases.

[0048] That is, by repeating these two stages, the inductor converts and transfers electrical energy during the charge and discharge process, resulting in an output voltage higher than the input voltage, thus achieving a voltage boost. The output voltage depends on the duty cycle of the switch Q1, that is, the proportion of the on-time in a cycle. A larger duty cycle results in a higher output voltage, and vice versa. The stability of the output voltage depends on the size of the output filter capacitor: a larger capacitor reduces the output voltage ripple, and vice versa. The output current depends on the value of the sampling resistor: a smaller resistance results in a higher output current, and vice versa. The stability of the output current depends on the feedback and protection features of the integrated circuit. The integrated circuit can adjust the duty cycle of the switch Q1 based on the comparison of the voltage on the feedback pin with the reference voltage to maintain a constant output current. It also provides overvoltage, overcurrent, and overtemperature protection to prevent circuit damage.

[0049] It should be noted that, in this embodiment, the first dimming unit 110, the second dimming unit 120 and the compensation unit 130 are individually regulated, that is, the main control module 100 individually controls the first dimming unit 110, the second dimming unit 120 and the compensation unit 130 to increase or decrease the brightness of the high color temperature light source, the low color temperature light source and the compensation light source, so that the color temperature scale after the combined light falls on the blackbody locus, thereby reducing color tolerance and improving light quality.

[0050] In addition, the LED boost circuit can be divided into three operating modes according to whether the current in the inductor is continuous: continuous conduction mode (CCM), critical conduction mode (BCM) and discontinuous conduction mode (DCM).

[0051] The light color temperature adjustment circuit of this embodiment is electrically connected to the main control module 100 via a first dimming unit 110, which is used to drive and adjust the high color temperature light source. It is then electrically connected to the main control module 100 via a second dimming unit 120, which is used to drive and adjust the low color temperature light source to combine with the high color temperature light source. Finally, it is electrically connected to the main control module 100 via a compensation unit 130, which is used to drive and adjust the compensation light source, compensating the color temperature of the combined light so that the color temperature coordinates of the combined light fall on the blackbody locus. Compared to existing solutions that use two-color light combination to adjust color temperature, the light color temperature adjustment circuit of this embodiment uses the main control module 100 to independently control the compensation unit 130 to drive and adjust the compensation light source, compensating the color temperature of the combined light of the high and low color temperature light sources so that the color temperature coordinates of the combined light fall on the blackbody locus, reducing color tolerance and improving light quality.

[0052] More specifically, in the following embodiments, a cool white LED light source, a warm white LED light source, and a red LED light source are selected, and three constant current drivers are connected to the three-color light sources respectively, and the brightness of the three-color lamp beads is controlled by the PWM port of the MCU respectively. The duty cycle of the three lamp beads is 100%, and finally the color temperature coordinates after combined light fall on the blackbody trajectory, reducing color tolerance and improving light quality.

[0053] 1. Choose cool white lamp beads with a color temperature of 7000K-8500K, warm white lamp beads with a color temperature of 1500K-2500K, and red lamp beads with a wavelength between 635nm-670nm.

[0054] 2. MCU controls three constant current drivers, which are connected to three-color lamp beads respectively. PWM controls the brightness of the lamp beads, and the total duty cycle of the three colors is 100%.

[0055] 3. The steps are as follows:

[0056] First, from the knowledge of colorimetry, we know that the chromaticity coordinates of the mixed light must be on the line connecting the chromaticity coordinates of the two light sources involved in the mixing. The specific position depends on the mixing ratio of the two light sources. The geometric constraints of two-channel PWM mixing are expressed as follows:

[0057] Where: x c 、y c and x w 、y w They are the color coordinates of the cold white light source (high color temperature LED) and the warm white light source (low color temperature LED) participating in the light mixing at full current and a duty cycle of 100%; m 、y m is the color coordinate of the two-color mixed light. Similarly, the color temperature coordinates of the cold and warm white mixed colors and the red LED mixed light are the coordinate point P, which is on the color temperature line of the blackbody locus.

[0058] Where: x R 、y R is the color coordinate of the red LED participating in the light mixing at full current and 100% duty cycle, x p 、y p is the color coordinate of the three-color mixed light.

[0059] The above two formulas are used to determine the required x when the red coordinates are known. P 、y P , we can deduce that x m 、y m In PWM dimming technology, it can be roughly considered that the LED output luminosity and the maximum luminosity are in direct proportion to each other, according to Grassmann's color law. z ----------------------------------------------------------(3) Y z =D c Y c +D w Y w +D R Y R --------------------------------(4) Y m D c Y c +D w Y w -------------------------------------------(5)

[0060] Among them, Y z is the total luminosity of the three-color mixed light, Y m Y is the photometric value of the mixed light of high color temperature LED and low color temperature LED, c is the photometric value of the high color temperature LED, Y w is the photometric value of the low color temperature LED, Y R is the photometric value of the red LED. D c 、D w 、D R are the duty cycles of high color temperature LED, low color temperature LED and red LED, respectively. c '、D w ' are the duty ratios of the cold and warm white LEDs in the dual-color light combination, respectively. According to the cold and warm dual-color light combination formula and the tristimulus value calculation formula: ----------------------------------------(8) D m =D w '+D c '

[0061] The duty cycle of the three colors can be obtained through the above formula.

[0062] Furthermore, in this embodiment, the high color temperature light source is the cool white light group 112, and the low color temperature light source is the warm white light group 122. Specifically, the first dimming unit 110 includes a first driver module 111 and a cool white light group 112, wherein the first driver module 111 is electrically connected to the cool white light group 112 and the main control module 100; the second dimming unit 120 includes a second driver module 121 and a warm white light group 122, wherein the second driver module 121 is electrically connected to the warm white light group 122 and the main control module 100; and the compensation unit 130 also includes a first compensation light group, which is electrically connected to the first compensation driver module 131. It should be noted that the number of light groups in this embodiment is in a certain proportional relationship. For example, if there are two cool white light groups 112 and two warm white light groups 122, the number of compensation light groups will also increase to two. Of course, in other embodiments, the proportional relationship of the light group components can be adjusted accordingly according to actual needs to suit different scenarios.

[0063] 1 and 2 , in this embodiment, the first compensation light group is a red light group 132 . It should be noted that the first compensation light group in this embodiment is only an example of the red light group 132 . Of course, in other embodiments, the first compensation light group may be a green light group 134 .

[0064] The light color adjustment circuit of this embodiment uses a red light assembly 132 as color temperature compensation. Adding a red light assembly 132 to the existing light source lowers the overall color temperature, creating a warmer light tone. This saves energy and reduces costs. The red light assembly 132 generally consumes less power than the existing light source. Furthermore, red light has a longer wavelength, lower energy, and generates less heat. Therefore, using a red light assembly 132 as the compensation lamp assembly reduces power consumption, extends the life of the lighting device, and reduces maintenance costs. The light color temperature compensation circuit of this embodiment uses the red light assembly 132 to compensate for the color temperature coordinate curve and the blackbody curve, reducing the color tolerance of the lighting device, improving light quality, and minimizing color variations between lighting devices.

[0065] Specifically, the red light assembly 132 in this embodiment preferably has a wavelength of 635nm-670nm. Of course, in some embodiments, the wavelength of the red light assembly 132 can be adjusted accordingly based on actual needs. Furthermore, the color temperature of the cool white light assembly 112 is 7000K-8500K, and the color temperature of the warm white light assembly 122 is 1500K-2500K.

[0066] In another embodiment, the compensation lamp group can be a green light group 134. As shown in Figure 2, the compensation unit 130 also includes a second compensation driver module 133 and a second compensation lamp group. The second compensation driver module 133 is electrically connected to the main control module 100 and the second compensation lamp group. The second compensation module drives and regulates the second compensation lamp group according to control signals from the main control module 100. Furthermore, the second compensation lamp group is a green light group 134. In this way, the combination of the green light group 134 and the red light group 132 can achieve color temperature compensation while improving the display color index and enhancing color reproduction. Color reproduction refers to the deviation of the color of an object when illuminated by a light source compared to the color under natural light, and is expressed by the color rendering index (Ra). The higher the color rendering index, the better the color reproduction and the more realistic the color of the object. Generally speaking, a light source with a single color temperature has a low color rendering index, which easily distorts the color of the object. On the other hand, a light source with multiple color temperatures has a higher color rendering index, making the color of the object closer to natural light. The green light group 134 and the red light group 132 are mixed to adjust the color temperature. While achieving color temperature compensation, the color component of the light source can be increased, the color rendering index of the light can be improved, and the color of the object can be made more vivid and natural.

[0067] 3 and 4 , in this embodiment, the first driving module 111 , the second driving module 121 , the first compensation driving module 131 , and the second compensation driving module 133 all include:

[0068] Energy storage circuit 200, electrically connected to the external DC power supply and the lamp assembly;

[0069] The control module 210 is electrically connected to the main control module 100 and is used to receive control signals from the main control module 100;

[0070] The sampling control circuit 220 is electrically connected to the output end of the control module 210, and the collection end of the sampling control circuit 220 is electrically connected to the energy storage circuit 200 for collecting the current of the charging circuit. It should be noted that the energy storage circuit 200 in this embodiment includes an inductor, a diode, and an output filter capacitor. Its main function is to store and release energy in the inductor to achieve the conversion of input voltage and output voltage. When the switch tube Q1 is turned on, the inductor is charged, the current increases linearly, and the inductor stores energy; when the switch tube Q1 is turned off, the inductor is discharged, the current decreases linearly, and the inductor releases energy. By repeating this process continuously, the inductor realizes energy conversion and transfer during charging and discharging, so that the output voltage is higher than the input voltage, achieving the purpose of boosting.

[0071] The diode prevents reverse current and protects the circuit and load. When the switch tube Q1 is turned on, the diode is cut off, which is equivalent to an open circuit, preventing the output filter capacitor from discharging to the ground; when the switch tube Q1 is turned off, the diode is turned on, which is equivalent to a short circuit, allowing the inductor and the input voltage to jointly charge the output filter capacitor and the load. The output filter capacitor is used to smooth the output voltage and improve the stability of the output voltage. Due to the switching of the switch tube Q1, the output voltage will have ripple, that is, periodic fluctuations, which will affect the normal operation of the load. The output filter capacitor can discharge to the load when the switch tube Q1 is turned on, and charge to the load (LED light group) when the switch tube Q1 is turned off, thereby reducing the ripple of the output voltage and making the output voltage closer to constant.

[0072] The light color temperature adjustment circuit of this embodiment uses energy storage circuit 200 to store energy, which is used to boost the input voltage, resulting in an output voltage higher than the input voltage. Control module 210 then receives pulse signals from main control module 100 to control the on / off switching of sampling control circuit 220, thereby adjusting the brightness of the light group and controlling the compensation amount of the compensation light group.

[0073] Furthermore, referring to FIG3 , in this embodiment, the sampling control circuit 220 includes:

[0074] The switch tube Q1 has a conduction terminal S1 electrically connected to the charging circuit;

[0075] The current sampling module 221 is electrically connected to the other conducting end D1 of the switch tube Q1;

[0076] The current comparator 222 is electrically connected to the control module 210. An input terminal 222a of the current comparator 222 is electrically connected to the current sampling module 221, and an output terminal 222b is electrically connected to the gate G of the switch tube Q1. It should be noted that the switch in this embodiment is an N-channel MOS transistor. Of course, in other embodiments, a P-channel MOS transistor can be used according to specific needs.

[0077] Furthermore, the current sampling module 221 in this embodiment can utilize a resistor, utilizing Ohm's law to convert the current into a voltage across the resistor, which is then amplified and acquired using an operational amplifier or analog-to-digital converter. Resistors have the advantages of good linearity, high precision, and fast response, making them suitable for sampling both DC and AC currents. Of course, in other embodiments, current transformers or Hall sensors may also be employed, without particular limitation herein.

[0078] The light color temperature adjustment circuit in this embodiment uses a current sampling module 221 to collect circuit current and feed it back to a current comparator 222. The current comparator 222 compares the current with a reference current and outputs a corresponding level signal to control the on / off of the switch Q1.

[0079] To precisely control color temperature compensation, this can be achieved by acquiring the current of the red light group 132. Therefore, in this embodiment, the control circuit also includes a light group current sampling module 221. The output end of the light group current sampling module 221 is electrically connected to a current comparator 222, and the acquisition end is electrically connected to the negative terminal of the light group. In this way, the current comparator 222 can obtain the current of the red light group 132 in real time through the light group current sampling module 221, and then output a corresponding level signal in real time, achieving precise control of the brightness of the red light group 132 and performing color temperature compensation in real time, so that the color temperature coordinates of the combined light fall on the blackbody locus, reducing color tolerance and improving light quality.

[0080] The present invention further proposes a lighting device that includes a light color temperature adjustment circuit. The specific structure of the light color temperature adjustment circuit is similar to that of the aforementioned embodiments. Since this lighting device utilizes all the technical solutions of all of the aforementioned embodiments, it at least possesses all the technical effects provided by the technical solutions of the aforementioned embodiments, and therefore will not be further elaborated here. The lighting device primarily comprises a housing, within which are mounted a cold light group, a warm light group, a red light group 132, and a green light group 134. During use, the red light group 132 and the green light group 134 can perform color temperature compensation, aligning the color temperature coordinate curve with the blackbody curve. This reduces the color tolerance of the lighting device, improves light quality, and minimizes color variations between lighting devices.

[0081] The above description is only a partial or preferred embodiment of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. Any equivalent structural transformation made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields, is included in the scope of protection of the present invention.

Claims

1. A light color temperature adjustment circuit, characterized in that: include: Main control module; a first dimming unit, electrically connected to the main control module, for driving a high color temperature light source; a second dimming unit, electrically connected to the main control module, for driving the low color temperature light source to mix light with the high color temperature light source; The compensation unit includes a first compensation driving module, which is electrically connected to the main control module and adjusts the brightness of the compensation light source according to a control signal from the main control module to perform color temperature compensation.

2. The light color temperature adjustment circuit according to claim 1, characterized in that: The first dimming unit includes a first driving module and a cool white lamp group, and the first driving module is electrically connected to the cool white lamp group and the main control module; the second dimming unit includes a second driving module and a warm white lamp group, and the second driving module is electrically connected to the warm white lamp group and the main control module; the compensation unit also includes a first compensation lamp group, and the first compensation lamp group is electrically connected to the first compensation driving module.

3. The light color temperature adjustment circuit according to claim 2, characterized in that: The first compensation lamp group is a red light lamp group.

4. The light color temperature adjustment circuit according to claim 3, characterized in that: The color temperature of the cool white lamp group is 7000K-8500K, the color temperature of the warm white lamp group is 1500K-2500K, and the wavelength of the red light group is 635nm-670nm.

5. The light color temperature adjustment circuit according to claim 3 or 2, characterized in that: The compensation unit also includes a second compensation driving module and a second compensation lamp group. The second compensation driving module is electrically connected to the main control module and the second compensation lamp group. The second compensation module drives and adjusts the second compensation lamp group according to the control signal of the main control module.

6. The light color temperature adjustment circuit according to claim 4, characterized in that: The second compensation lamp group is a green light lamp group.

7. The light color temperature adjustment circuit according to claim 5, characterized in that: The first driving module, the second driving module, the first compensation driving module, and the second compensation driving module each include: an energy storage circuit electrically connected to the external DC power supply and the lamp assembly for storing or releasing electrical energy; a control module, electrically connected to the main control module and configured to receive a control signal from the main control module; The sampling control circuit is electrically connected to the output end of the control module, and the collection end of the sampling control circuit is electrically connected to the energy storage circuit for collecting the current of the energy storage circuit.

8. The light color temperature adjustment circuit according to claim 7, characterized in that: The sampling control circuit includes: A switch tube, one conducting end of which is electrically connected to the energy storage circuit a current sampling module, electrically connected to the other conducting end of the switch tube; A current comparator is electrically connected to the control module, an input end of the current comparator is electrically connected to the current sampling module, and an output end is electrically connected to the gate of the switch tube, for controlling the conduction or disconnection of the switch tube.

9. The light color temperature adjustment circuit according to claim 8, characterized in that: The sampling control circuit further includes: The lamp group current sampling module has an output end electrically connected to the current comparator and a collection end electrically connected to the negative electrode of the lamp group.

10. A lighting device, characterized in that: The light color temperature adjustment circuit comprises the light color temperature adjustment circuit according to any one of claims 1 to 9.

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