Color temperature adjustable lighting device, color temperature adjustment circuit / chip and LED device

Abstract

The present invention provides a color temperature adjustable lighting device, a color temperature adjustment circuit / chip, and an LED device. The color temperature adjustable lighting device includes: a first lighting component; a second lighting component connected in parallel with the first lighting component; a color temperature adjustment module connected in series with the first lighting component and the second lighting component, and adjusting the currents flowing through the first lighting component and the second lighting component respectively by setting the resistance value of its own resistor; a control module connected to the color temperature adjustment module, outputting a pulse width adjustable control signal to control the equivalent output resistance of the color temperature adjustment module, so as to realize the adjustable mixed color temperature of the first lighting component and the second lighting component. The present invention can finely adjust the resistance value of the relevant resistor in the color temperature adjustment module, and can realize fine color temperature adjustment without moving the control module. Even when using LED components with different bins, it can ensure the consistency of the output target color temperature among individual lighting devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of lighting, and relates to a light-emitting device, in particular to a color temperature adjustable light-emitting device, a color temperature adjustment circuit / chip, and an LED device. Background Art

[0002] The human eye has a very high resolution for the color and brightness of light, especially being very sensitive to the differences and changes in color. In the early days, since LEDs were mainly used as indicator or display lights and generally appeared as single devices, the requirements for sorting their wavelengths and controlling their brightness were not high. However, with the continuous improvement of the efficiency and brightness of LEDs, their application scope has become wider and wider. When LEDs are used as array display and screen elements, due to the sensitivity of the human eye to the wavelength and brightness of colors, using unsorted LEDs results in unevenness, which in turn affects people's visual effects. Whether the wavelength is uneven or the light brightness is uneven will give people an uncomfortable feeling. The sorting of LEDs cannot cover all parameters such as optical, electrical characteristics, lifespan, and reliability, but is classified and sorted according to several key parameters that are generally concerned by everyone, including the peak wavelength, luminous intensity, luminous flux, color temperature, operating voltage, reverse breakdown voltage, etc.

[0003] An existing sorting method is to sort in the form of LED tubes, and the test sorter will automatically pack the LEDs into different bins according to the settings. Due to the increasingly strict requirements for LEDs, the early sorters had 32 bins, which was later increased to 64 bins, and now there are already commercial sorters with 72 bins. Even so, the number of bins still cannot meet the production and market demands, and this is still the case in the lighting field. For the production of the same type of lamp, it is impossible to ensure that all the purchased LEDs are of the same bin, which leads to visible differences in brightness or color temperature of the same type of lamp, seriously affecting the product quality and customer trust. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a color temperature adjustable light-emitting device, a color temperature adjustment circuit / chip, and an LED device, which are used to solve the problem that there is a difference between the output color temperature and the target color temperature when using LEDs of different bins in existing light-emitting components.

[0005] To achieve the above and other related objectives, the present invention provides a color temperature adjustable lighting device, which includes: a first lighting component; a second lighting component, connected in parallel with the first lighting component; a color temperature adjustment module, connected in series with the first lighting component and the second lighting component, for adjusting the currents flowing through the first lighting component and the second lighting component respectively; and a control module, connected to the color temperature adjustment module, outputting a pulse width adjustable control signal to control the equivalent output resistance of the color temperature adjustment module, so as to achieve adjustable mixed color temperature of the first lighting component and the second lighting component.

[0006] In an embodiment of the present invention, the color temperature adjustment module includes two variable resistance modules; one variable resistance module is connected in series with the first lighting component, and the other variable resistance module is connected in series with the second lighting component; the adjustable end of the variable resistance module is connected to the output end of the control module.

[0007] In an embodiment of the present invention, the control module is provided with two output ends for respectively outputting one path of pulse width adjustable control signal; the two output ends of the control module are connected to the adjustable ends of the two variable resistance modules in one-to-one correspondence.

[0008] In an embodiment of the present invention, the color temperature adjustment module includes a first control end, a second control end, a first positive end, a second positive end, and a negative end; the first control end is the adjustable end of the one variable resistance module, and the first positive end is the positive end of the one adjustable resistance module; the second control end is the adjustable end of the other variable resistance module, and the second positive end is the positive end of the other adjustable resistance module; the negative end is the negative end of the two variable resistance modules; the first control end is connected to an output end of the control module, and the second control end is connected to the other output end of the control module; the first positive end is connected to the negative pole of the first lighting component, and the second positive end is connected to the negative pole of the second lighting component; the negative end is used to be connected to the negative pole of a power supply; the positive pole of the first lighting component is used to be connected to the positive pole of the power supply, and the positive pole of the second lighting component is used to be connected to the positive pole of the power supply.

[0009] In an embodiment of the present invention, the color temperature adjustment module further includes a voltage dividing module; the voltage dividing module is connected in parallel with the one variable resistance module, and the output end of the voltage dividing module is connected to the adjustable end of the other variable resistance module; the adjustable end of the one variable resistance module is connected to the output end of the control module.

[0010] In an embodiment of the present invention, the color temperature adjustment module includes a first control end, a first positive end, a second positive end, and a negative end; the first control end is the adjustable end of the variable resistor module, and the first positive end is the positive end of the adjustable resistor module; the negative end is the negative ends of two variable resistor modules; the first control end is connected to the output end of the control module; the first positive end is connected to the negative pole of the first light-emitting component, and the second positive end is connected to the negative pole of the second light-emitting component; the negative end is used to be connected to the negative pole of a power supply; the positive pole of the first light-emitting component is used to be connected to the positive pole of the power supply, and the positive pole of the second light-emitting component is used to be connected to the positive pole of the power supply.

[0011] In an embodiment of the present invention, the variable resistor module includes a MOS transistor, a first resistor, a second resistor, a positive end, a negative end, and an adjustable end; the gate of the MOS transistor is connected to the adjustable end, the source of the MOS transistor is connected to one end of the second resistor, and the drain of the MOS transistor is connected to the positive end; one end of the first resistor is connected to the drain of the MOS transistor, and the other end of the first resistor is connected to the negative end; the other end of the second resistor is connected to the negative end; the adjustable end is connected to the output end of the control module.

[0012] In an embodiment of the present invention, the first light-emitting component includes a group of LED circuits; the second light-emitting component includes a group of LED circuits; the color temperatures of the first light-emitting component and the second light-emitting component are different.

[0013] In an embodiment of the present invention, the control module outputs a pulse-width adjustable control signal with a duty cycle of δ to control the equivalent output resistance of the variable resistor module in the color temperature adjustment module to be VR: Wherein, when the variable resistor module is powered by a constant current source, the current flowing through the variable resistor module is constant at I; when the variable resistor module receives the high level of the pulse-width adjustable control signal, the MOS transistor in the variable resistor module is turned on, and the equivalent resistance between the positive end and the negative end of the variable resistor module is the parallel connection of the first resistor RA and the second resistor RB, that is, the resistance value of the equivalent resistance is At this time, the voltage between the positive end and the negative end of the variable resistor module is U′ = I·R′; when the variable resistor module receives the low level of the pulse-width adjustable control signal, the MOS transistor in the variable resistor module is turned off, and only the first resistor RA is turned on between the positive end and the negative end of the variable resistor module. At this time, the voltage between the positive end and the negative end of the variable resistor module is U” = I·RA; the average voltage between the positive end and the negative end of the variable resistor module within the entire PWM cycle is: During the entire PWM cycle, the average resistance value between the positive and negative terminals of the variable resistor module is the equivalent output resistance VR of the variable resistor module.

[0014] In an embodiment of the present invention, the control module outputs a pulse-width adjustable control signal with a duty cycle of δ to control the equivalent output resistance of the variable resistor module in the color temperature adjustment module to be VR: Wherein, when the variable resistor module is powered by a constant voltage source, the voltage between the positive and negative terminals of the variable resistor module is constantly U; when the variable resistor module receives the high level of the pulse-width adjustable control signal, the current flowing into the positive and negative terminals of the variable resistor module is When the variable resistor module receives the low level of the pulse-width adjustable control signal, the current flowing into the positive and negative terminals of the variable resistor module is During the entire PWM cycle, the average value of the current flowing into the positive and negative terminals of the variable resistor module is: During the entire PWM cycle, the average resistance value between the positive and negative terminals of the variable resistor module is the equivalent output resistance VR of the variable resistor module.

[0015] In an embodiment of the present invention, the control module outputs a pulse-width adjustable control signal with a duty cycle of δ1 to control the equivalent output resistance of a variable resistor module in the color temperature adjustment module to be VR1, and outputs a pulse-width adjustable control signal with a duty cycle of δ2 to control the equivalent output resistance of another variable resistor module in the color temperature adjustment module to be VR2. Then the equivalent output resistance of the color temperature adjustment module is VR; when powered by a constant current source I , , LED2 ,

[0015] , , total , , LED1 , ,

[0016] to the color temperature adjustable light-emitting device, the voltage drop of the first light-emitting component is V LED1 , and the average current flowing through the first light-emitting component is I1; the voltage drop of the second light-emitting component is V LED2 , and the average current flowing through the second light-emitting component is I2; according to the relationship it can be known that by changing the duty cycle of any one of the two pulse-width adjustable control signals by the control module, VR2 / VR1 can be changed, and further the current ratio flowing through the first light-emitting component and the second light-emitting component can be changed, so that the light-emitting ratio of the first light-emitting component and the second light-emitting component is changed, and the mixed color temperature of the first light-emitting component and the second light-emitting component is changed.

[0016] The present invention also provides a color temperature adjustment chip for controlling the mixed color temperature of at least two groups of light-emitting components. The color temperature adjustment chip includes: a color temperature adjustment module connected in series with each of the at least two groups of light-emitting components respectively, for adjusting the current flowing through each light-emitting component; a control module connected to the color temperature adjustment module, outputting a pulse-width adjustable control signal to control the equivalent output resistance of the color temperature adjustment module, so as to realize adjustable mixed color temperature of the at least two groups of light-emitting components.

[0017] In an embodiment of the present invention, the color temperature adjustment module includes at least two variable resistance modules; each variable resistance module is connected in series with each light-emitting component in one-to-one correspondence; the adjustable end of the variable resistance module is connected to the output end of the control module.

[0018] In an embodiment of the present invention, the color temperature adjustment chip further includes: a communication module communicatively connected to the control module, for receiving a duty cycle setting instruction of the pulse-width adjustable control signal.

[0019] The present invention also provides a color temperature adjustment chip, which includes the color temperature adjustment circuit as described above.

[0020] The present invention also provides an LED device, which includes the color temperature adjustable light-emitting device as described above.

[0021] The present invention also provides an LED device, which includes the color temperature adjustment circuit as described above.

[0022] The present invention also provides an LED device, which includes the color temperature adjustment chip as described above.

[0023] As described above, the color temperature adjustable light-emitting device, color temperature adjustment circuit / chip and LED device of the present invention have the following beneficial effects:

[0024] The present invention can finely adjust the resistance value of the relevant resistors in the color temperature adjustment module. Without moving the control module, it can realize fine color temperature adjustment. Even when using LED components with different bins, it can ensure the consistency of the output target color temperature among individual light-emitting devices, which is not only beautiful and of high quality, but also convenient for production and supply chain management. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It shows a schematic structural diagram of an implementation of the color temperature adjustable light-emitting device according to an embodiment of the present invention.

[0026] Figure 2 It shows a schematic structural diagram of an implementation of the color temperature adjustment module of the color temperature adjustable light-emitting device according to an embodiment of the present invention.

[0027] Figure 3AIt shows a schematic diagram of an implementation structure of the control module of the color temperature adjustable lighting device according to an embodiment of the present invention.

[0028] Figure 3B It shows a schematic diagram of a port structure of the color temperature adjustment module of the color temperature adjustable lighting device according to an embodiment of the present invention.

[0029] Figure 3C and Figure 3D It shows a schematic diagram of an example circuit structure of the color temperature adjustment module of the color temperature adjustable lighting device according to an embodiment of the present invention.

[0030] Figure 4A It shows another schematic diagram of an implementation structure of the control module of the color temperature adjustable lighting device according to an embodiment of the present invention.

[0031] Figure 4B It shows another schematic diagram of a port structure of the color temperature adjustment module of the color temperature adjustable lighting device according to an embodiment of the present invention.

[0032] Figure 4C It shows another schematic diagram of an example circuit structure of the color temperature adjustment module of the color temperature adjustable lighting device according to an embodiment of the present invention.

[0033] Figure 4D It shows a third schematic diagram of an example circuit structure of the color temperature adjustment module of the color temperature adjustable lighting device according to an embodiment of the present invention.

[0034] Figure 5A It shows a schematic diagram of an implementation structure of the color temperature adjustment circuit according to an embodiment of the present invention.

[0035] Figure 5B It shows a schematic diagram of an implementation structure of the color temperature adjustment module of the color temperature adjustment circuit according to an embodiment of the present invention.

[0036] Figure 5C It shows another schematic diagram of an implementation structure of the color temperature adjustment circuit according to an embodiment of the present invention. Detailed implementation manners

[0037] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0038] It should be noted that the illustrations provided in the following embodiments only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0039] Please refer to Figure 1 , the present invention provides a color temperature adjustable lighting device. The color temperature adjustable lighting device 100 includes: a first lighting component 110, a second lighting component 120, a color temperature adjustment module 130, and a control module 140.

[0040] The first lighting component is used for lighting and includes a group of LEDs; this group of LEDs can be formed by connecting any number of LEDs in series, parallel, or in a mixed connection manner.

[0041] The second lighting component is connected in parallel with the first lighting component. The second group of lighting components is usually the same as the first group of lighting components in structure. The second lighting component is used for lighting and includes a group of LEDs; this group of LEDs can be formed by connecting any number of LEDs in series, parallel, or in a mixed connection manner. There is a deviation in the color temperature of the first lighting component and the second lighting component due to different bins of the LEDs.

[0042] The color temperature adjustment module is connected in series with the first lighting component and the second lighting component, and adjusts the currents flowing through the first lighting component and the second lighting component respectively by setting the resistance value of its own resistor. The present invention can finely adjust the resistance value of the relevant resistors in the color temperature adjustment module, and can finely adjust the color temperature without moving the control module. When using LED components with different bins, it can ensure the consistency of the target color temperature output by the lamp.

[0043] The control module is connected to the color temperature adjustment module and outputs a pulse width adjustable control signal to control the equivalent output resistance of the color temperature adjustment module, so as to realize the adjustable mixed color temperature of the first lighting component and the second lighting component. The present invention uses a PWM signal to control the equivalent impedance of the variable resistor module to change, so as to change the current of different color temperature LED groups, achieving the purpose of color temperature adjustment. Compared with directly changing the combination method of the LED groups by a switch, the present invention can conveniently generate more mixing ratios and output more kinds of color temperatures.

[0044] See Figure 2 As shown, in an embodiment of the present invention, the color temperature adjustment module includes 2 variable resistor modules 131; one variable resistor module is connected in series with the first lighting component, and the other variable resistor module is connected in series with the second lighting component; the adjustable end of the variable resistor module is connected to the output end of the control module.

[0045] The present invention can finely adjust the resistance value of relevant resistors in a variable resistor module. Without moving the control module, the color temperature can be finely adjusted. When using LED components with different bins, it can ensure the consistency of the target color temperature output of the lamp, which is beautiful, of high quality, and convenient for production and supply chain management.

[0046] See Figure 3A As shown, in an embodiment of the present invention, the control module is provided with 2 output terminals for respectively outputting 1 path of pulse-width adjustable control signal; the 2 output terminals of the control module are respectively and correspondingly connected to the adjustable terminals of the 2 variable resistor modules.

[0047] See Figure 3B As shown, in an embodiment of the present invention, the color temperature adjustment module includes a first control terminal, a second control terminal, a first positive terminal, a second positive terminal, and a negative terminal; the first control terminal is the adjustable terminal of the one variable resistor module, and the first positive terminal is the positive terminal of the one adjustable resistor module; the second control terminal is the adjustable terminal of the other variable resistor module, and the second positive terminal is the positive terminal of the other adjustable resistor module; the negative terminal is the negative terminal of the 2 variable resistor modules; the first control terminal is connected to an output terminal of the control module, and the second control terminal is connected to the other output terminal of the control module; the first positive terminal is connected to the negative electrode of the first light-emitting component, and the second positive terminal is connected to the negative electrode of the second light-emitting component; the negative terminal is used to be connected to the negative electrode of a power supply; the positive electrode of the first light-emitting component is used to be connected to the positive electrode of the power supply, and the positive electrode of the second light-emitting component is used to be connected to the positive electrode of the power supply.

[0048] See Figure 3C and Figure 3D As shown in and, in an embodiment of the present invention, the variable resistor module 131 includes a MOS transistor, a first resistor, a second resistor, a positive terminal, a negative terminal, and an adjustable terminal; the gate of the MOS transistor is connected to the adjustable terminal, the source of the MOS transistor is connected to one end of the second resistor, and the drain of the MOS transistor is connected to the positive terminal; one end of the first resistor is connected to the drain of the MOS transistor, and the other end of the first resistor is connected to the negative terminal; the other end of the second resistor is connected to the negative terminal; the adjustable terminal is connected to the output terminal of the control module.

[0049] Figures 3A to 3C The working principle of is described as follows:

[0050] Scenario 1: When the variable resistor module is powered by a constant current source, the current flowing through the variable resistor module is constantly I; the control module outputs a pulse-width adjustable control signal with a duty cycle of δ to control the equivalent output resistance VR of the variable resistor module in the color temperature adjustment module:

[0051]

[0052] Among them, when the variable resistance module receives the high level of the pulse width adjustable control signal, the MOS transistor in the variable resistance module is turned on, and the equivalent resistance between the positive and negative terminals of the variable resistance module is the parallel connection of the first resistor RA and the second resistor RB, that is, the resistance value of the equivalent resistance is At this time, the voltage between the positive and negative terminals of the variable resistance module is U′ = I·R′;

[0053] When the variable resistance module receives the low level of the pulse width adjustable control signal, the MOS transistor in the variable resistance module is turned off, and only the first resistor RA conducts between the positive and negative terminals of the variable resistance module. At this time, the voltage between the positive and negative terminals of the variable resistance module is U” = I·RA;

[0054] The average voltage between the positive and negative terminals of the variable resistance module within the entire PWM period is:

[0055]

[0056] Within the entire PWM period, the average resistance value between the positive and negative terminals of the variable resistance module, that is, the equivalent output resistance VR of the variable resistance module, is:

[0057]

[0058] Scenario 2: When the variable resistance module is powered by a constant voltage source, the voltage between the positive and negative terminals of the variable resistance module is constantly U; the control module outputs a pulse width adjustable control signal with a duty cycle of δ to control the equivalent output resistance VR of the variable resistance module in the color temperature adjustment module:

[0059]

[0060] Among them, when the variable resistance module receives the high level of the pulse width adjustable control signal, the current flowing into the positive and negative terminals of the variable resistance module is

[0061] When the variable resistance module receives the low level of the pulse width adjustable control signal, the current flowing into the positive and negative terminals of the variable resistance module is

[0062] Within the entire PWM period, the average value of the current flowing into the positive and negative terminals of the variable resistance module is:

[0063] During the entire PWM cycle, the average resistance between the positive and negative terminals of the variable resistor module is the equivalent output resistance VR of the variable resistor module, which is:

[0064]

[0065] In summary, whether it is a constant voltage source or a constant current source supplying power to the variable resistor module, the equivalent resistance, i.e., the average resistance, between its terminal 1 and terminal 2 is related to the duty cycle δ of the pulse width adjustable control signal (PWM). By changing the duty cycle δ, the resistance value of the average resistance (or equivalent resistance) between the positive terminal (terminal 1) and the negative terminal (terminal 2) of the variable resistor module can be changed, thereby changing the current flowing through the first light-emitting component or / and the second light-emitting component, and realizing the adjustment of the hybrid color temperature of the light-emitting device.

[0066] See Figure 4A As shown, in an embodiment of the present invention, the color temperature adjustment module 130 includes two variable resistor modules 131 and a voltage dividing module 132; one variable resistor module is connected in series with the first light-emitting component, and the other variable resistor module is connected in series with the second light-emitting component; the voltage dividing module is connected in parallel with the one variable resistor module, and the output terminal of the voltage dividing module is connected to the adjustable terminal of the other variable resistor module; the adjustable terminal of the variable resistor module is connected to the output terminal of the control module.

[0067] The single-channel PWM signal control scheme adopted by the present invention simplifies the control method, makes the design of the control module easier to implement, and has a lower probability of control errors.

[0068] See Figure 4B As shown, in an embodiment of the present invention, the color temperature adjustment module includes a first control terminal, a first positive terminal, a second positive terminal, and a negative terminal; the first control terminal is the adjustable terminal of the one variable resistor module, and the first positive terminal is the positive terminal of the one adjustable resistor module; the negative terminal is the negative terminals of the two variable resistor modules; the first control terminal is connected to the output terminal of the control module; the first positive terminal is connected to the negative electrode of the first light-emitting component, and the second positive terminal is connected to the negative electrode of the second light-emitting component; the negative terminal is used to be connected to the negative electrode of a power supply; the positive electrode of the first light-emitting component is used to be connected to the positive electrode of the power supply, and the positive electrode of the second light-emitting component is used to be connected to the positive electrode of the power supply.

[0069] See Figure 4CAs shown, in an embodiment of the present invention, the variable resistor module 131 includes MOS transistors (Q1, Q2), first resistors (R1A, R2A), second resistors (R1B, R2B), a positive terminal, a negative terminal, and an adjustable terminal; the gates of the MOS transistors are connected to the adjustable terminal, the sources of the MOS transistors are connected to one end of the second resistors, and the drains of the MOS transistors are connected to the positive terminal; one end of the first resistors is connected to the drains of the MOS transistors, and the other ends of the first resistors are connected to the negative terminal; the other ends of the second resistors are connected to the negative terminal; the adjustable terminal is connected to the output terminal of the control module. The voltage division module includes a third resistor and a fourth resistor connected in series; one end of the third resistor is connected to the source of the MOS transistor, and the other end of the third resistor is connected to the adjustable terminal of the other variable resistor module; one end of the fourth resistor is connected to the other end of the third resistor, and the other end of the fourth resistor is connected to the negative terminal. The voltage division module 132 includes a resistor R3 and a resistor R4.

[0070] Figure 4D For the Figure 4C shown circuit structure, a deformed structure thereof has the same function as Figure 4C and can be used as Figure 4C a replacement solution. The voltage division module 132 includes a resistor R3, a resistor R4, and a zener diode D.

[0071] Figures 4A to 4C The working principle of

[0072] is described as follows:

[0073] Assume that the duty cycle of the PWM signal sent by the control module to a variable resistor module VR1 is δ1, the duty cycle of the PWM signal sent by the control module to another variable resistor module VR2 is δ2, the equivalent resistance value of the variable resistor module VR1 is VR1, and the equivalent resistance value of the variable resistor module VR2 is VR2. total .

[0074] When the LED is turned on, the voltage across its two ends can be regarded as a constant conduction voltage drop and is not affected by the magnitude of the current flowing through it. Denote the voltage drop of the first LED group (i.e., the first light-emitting component) as V LED1 , the average current flowing through it as I1; the voltage drop of the second LED group (i.e., the second light-emitting component) as V LED2 , and the current flowing through it as I2; from the Figure 4C shown circuit of Scheme 1, it can be known that:

[0075] V LED1 + I1·VR1 = V LED2 + I2·VR2 (Formula 3.1)

[0076] I total = I1 + I2 (Equation 3.2)

[0077] Substituting (Equation 3.2) into (Equation 3.1) gives:

[0078]

[0079] In the design of Solution 1, components with similar rated conduction voltage drops should be used for the two groups of LEDs with different color temperatures. Therefore, in Equation 2.2, the influence of V LED1 -V LED2 on I1 is so small that it can be ignored, and Equation 3.3 can be approximated as:

[0080]

[0081] Similarly, it can be obtained that:

[0082]

[0083] It can be seen that:

[0084]

[0085] Therefore, by changing the duty cycle of any one of the two PWM signals output by the control module, VR2 / VR1 can be changed, and the current ratio in the two groups of LEDs with different color temperatures can be changed, resulting in a change in the light-emitting ratio of the two groups of LEDs with different color temperatures, and thus the color temperature of the finally output light after mixing is also changed.

[0086] The DC power supply in Solution 1 is a constant voltage source or a constant current source, and both Equation 3.1 and Equation 3.2 hold. Therefore, the above conclusions are all correct.

[0087] Another solution, as shown by the dashed box in the appendix Figures 4A to 4C constitutes a dual-VR module with dual-variable equivalent resistance controlled by one-way PWM, where the equivalent resistance between terminal 1 and terminal 2 of the module is VR1, the equivalent resistance between terminal 4 and terminal 2 is VR2, and terminal 3 is the PWM signal receiving terminal. When the duty cycle of the received PWM signal changes, the resistance values of VR1 and VR2 change simultaneously and in opposite directions and magnitudes.

[0088] As shown in the appendix Figure 4CAs shown in the dashed box, the dual-VR module includes two MOSFETs Q1 and Q2. Their sources are connected to resistors R1B and R2B, respectively, and then to terminal 2. The drains of Q1 and Q2 are connected to terminals 1 and 4, respectively. The gate of Q1 is connected to terminal 3. Resistor R1A is connected between terminals 1 and 2, and resistor R2A is connected between terminals 4 and 2. In addition, resistors R3 and R4 are connected in series between terminals 1 and 2, and the midpoint between R3 and R4 is connected to the gate of Q2. When the PWM signal turns on Q1 at a high level, the source-drain voltage of Q1 decreases, causing the gate voltage of Q1 to be clamped to a low level, and Q1 is turned off. When the PWM signal turns Q1 off, the gate voltage of Q2 is the voltage across R4. The resistance values of R1A, R3, and R4 are appropriately designed so that R1A < <R3+R4,并使此时R4两端压降高于Q2的开通阈值,使Q2导通。可见Q1、Q2以反相工作。

[0089] set up Figure 4C The DC Power in the figure is a constant current source, and the output current is constant at I total The duty cycle of the PWM signal is δ, and the conduction voltage drop of the first LED group is V LED1 , the average current flowing through the first LED group is I1, and the conduction voltage drop of the second LED group is V LED2 , the average current flowing through the second LED group is I2. When the PWM signal is high, Q1 is turned on and Q2 is turned off. The current flowing through the first LED group is I1', and the current flowing through the second LED group is I2', and:

[0090] I total =I1′+I2′ (Formula 5.1)

[0091] From the circuit, we can see that at this time: V LED1 =V LED2 +I2′·R2A, we can deduce:

[0092]

[0093]

[0094] When the PWM signal is low, Q1 is turned off and Q2 is turned on. The current flowing through the first LED group is I1", and the current flowing through the second LED group is I2". <R3+R4,忽略此时R3和R4支路的电流,可得:V LED1 +I1”·R1A=V LED2 , because I total =I1”+I2”, we can deduce:

[0095]

[0096]

[0097] According to the definition of duty cycle, the average current flowing through the first LED group within the entire PWM cycle is:

[0098]

[0099]

[0100] As can be seen from Formula 5.6 and Formula 5.7, when the duty cycle of the PWM signal is changed, the average current flowing through the first LED group and the average current flowing through the second LED group both change, and the magnitude and direction of the change are opposite. That is, when the duty cycle δ increases, I1 increases and I2 decreases; when the duty cycle δ decreases, I1 decreases and I2 increases. Therefore, by changing the duty cycle δ of the PWM signal, the current ratio flowing through the first LED group and the second LED group can be changed, and the light-emitting ratio of the first LED group and the second LED group can be changed, resulting in a change in the color temperature of the output light after mixing.

[0101] In Solution 2, it can also be known from Formula 5.6 and Formula 5.7 that when the PWM duty cycle δ is determined, changing the resistance value of R1A or R2A can also change I1 and I2, and the magnitude and direction of the change are opposite. Once the control module is designed and determined, it will no longer change during mass production. That is, in the application of grading color temperature, after the duty cycle δ values of each grade output by the control module are determined, they will no longer change, which is beneficial to mass production. However, due to the batch differences in the parameters of current LED components, usually for LEDs of the same specification, different bins are distinguished according to their conduction voltage drop or color temperature. During mass production, in order to improve the component supply conditions, LED components of different bins need to be used to manufacture the same lighting product. And whether it is a slight difference in the LED conduction voltage drop or the component color temperature, it may cause a deviation in the color temperature output by the lighting fixture. When these lighting fixtures with color temperature deviations are installed in the same space, visible color temperature chaos of the lighting fixtures will occur, affecting the appearance. After adopting the present invention, for LED components of different bins, without changing the duty cycle of the PWM signal output by the control module, only a set of R1A and R2A needs to be determined according to the parameters of the LEDs of different bins, and the color temperature output of the lighting fixture can be accurately adjusted, ensuring that the lighting fixture outputs light with the target color temperature with high consistency, and simplifying the management of production and logistics.

[0102] In Solution 1, as can be seen from Formula 2.3 and Formula 3.6, when the duty cycles δ1 and δ2 of the PWM signals are both determined, by changing the RA resistance in VR1 or VR2, the equivalent resistance of the corresponding module can be changed, thereby changing the light-emitting ratio of the two groups of LEDs and the output color temperature of the lamp. Therefore, after the PWM signal is determined in the control module design, according to the bin parameters of the LEDs, by changing the RA resistance value in the module, the output color temperature of the lamp can be accurately adjusted to ensure that the lamp outputs light with the target color temperature with high consistency, and the management of production and logistics is simplified.

[0103] As shown in the appendix Figure 4C , the input of the control module of the present invention is connected to a multi-position switch. The control module determines the duty cycle of the output PWM signal according to the detected position of the switch. If the PWM duty cycles output at different switch positions are different, a light-emitting device with multi-level color temperature output controlled by a switch is formed.

[0104] Refer to Figure 5A As shown in the figure, the embodiment of the present invention further provides a color temperature adjustment circuit for controlling the mixed color temperature of at least two groups of light-emitting components. The color temperature adjustment circuit 500 includes: a color temperature adjustment module 510 and a control module 520. The color temperature adjustment module is respectively connected in series with the at least two groups of light-emitting components and is used to adjust the current flowing through each light-emitting component. The control module is connected to the color temperature adjustment module and outputs a pulse width adjustable control signal to control the equivalent output resistance of the color temperature adjustment module to realize the adjustable mixed color temperature of the at least two groups of light-emitting components.

[0105] Furthermore, refer to Figure 5B As shown in the figure, the color temperature adjustment module 510 includes at least two variable resistance modules; each variable resistance module is connected in series with each light-emitting component in one-to-one correspondence; the adjustable end of the variable resistance module is connected to the output end of the control module.

[0106] Refer to Figure 5C As shown in the figure, in an embodiment of the present invention, the color temperature adjustment circuit 500 further includes: a communication module 530. The communication module 530 is communicatively connected to the control module and is used to receive the duty cycle setting instruction of the pulse width adjustable control signal.

[0107] The embodiment of the present invention further provides a color temperature adjustment chip, and the color temperature adjustment chip includes the color temperature adjustment circuit of the present invention.

[0108] The embodiment of the present invention further provides an LED device, and the LED device includes the color temperature adjustable light-emitting device of the present invention.

[0109] The embodiment of the present invention further provides an LED device, and the LED device includes the color temperature adjustment circuit of the present invention.

[0110] An embodiment of the present invention further provides an LED device, and the LED device includes the color temperature adjustment chip of the present invention.

[0111] The present invention can finely adjust the resistance values of relevant resistors in the variable resistor module, and can finely adjust the color temperature without moving the control module. When using LED components with different bins, it can ensure the consistency of the target color temperature output by the lamp, which is beautiful and of high quality, and facilitates the management of production and the supply chain.

[0112] The present invention uses a PWM signal to control the equivalent impedance of the variable resistor module to change, so as to change the current of different color temperature LED groups, achieving the purpose of color temperature adjustment. Compared with directly changing the combination method of the LED groups by a switch, the present invention can conveniently generate more mixing ratios and output more color temperatures.

[0113] The single-channel PWM signal control scheme adopted by the present invention simplifies the control method, makes the design and implementation of the control module easier, and has a lower probability of control errors.

[0114] In summary, the present invention effectively overcomes various disadvantages in the prior art and has high industrial utilization value.

[0115] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A color temperature adjustable lighting device, characterized in that, The color temperature adjustable light-emitting device includes: A first light-emitting component; A second light-emitting component, connected in parallel with the first light-emitting component; A color temperature adjustment module, connected in series with the first light-emitting component and the second light-emitting component, and adjusting the currents flowing through the first light-emitting component and the second light-emitting component respectively by setting the resistance value of its own resistance; A control module, connected to the color temperature adjustment module, and outputting a pulse-width adjustable control signal to control the equivalent output resistance of the color temperature adjustment module, so as to realize the adjustable mixed color temperature of the first light-emitting component and the second light-emitting component; The color temperature adjustment module includes two variable resistance modules; one variable resistance module is connected in series with the first light-emitting component, and the other variable resistance module is connected in series with the second light-emitting component; the adjustable end of the variable resistance module is connected to the output end of the control module; The variable resistance module includes a MOS transistor, a first resistor, a second resistor, a positive terminal, a negative terminal and an adjustable end; the gate of the MOS transistor is connected to the adjustable end, the source of the MOS transistor is connected to one end of the second resistor, and the drain of the MOS transistor is connected to the positive terminal; one end of the first resistor is connected to the drain of the MOS transistor, the other end of the first resistor is connected to the negative terminal; the other end of the second resistor is connected to the negative terminal; the adjustable end is connected to the output end of the control module; The control module outputs a pulse-width adjustable control signal with a duty cycle of δ1 to control the equivalent output resistance of one variable resistance module in the color temperature adjustment module to be VR1, and outputs a pulse-width adjustable control signal with a duty cycle of δ2 to control the equivalent output resistance of the other variable resistance module in the color temperature adjustment module to be VR2, then the equivalent output resistance of the color temperature adjustment module is VR; When powered by a constant current source I total to the color temperature adjustable lighting device, the voltage drop of the first lighting component is V LED1 , and the average current flowing through the first lighting component is I1; the voltage drop of the second lighting component is V LED2 , and the average current flowing through the second lighting component is I2; According to the relational expression it can be known that by changing the duty cycle of any one of the two pulse-width adjustable control signals by the control module, VR2 / VR1 can be changed, and further the current ratio flowing through the first light-emitting component and the second light-emitting component can be changed, so that the light-emitting ratio of the first light-emitting component and the second light-emitting component is changed, and the mixed color temperature of the first light-emitting component and the second light-emitting component is changed.

2. The color temperature adjustable lighting device according to claim 1, wherein: The control module is provided with two output ends for respectively outputting one path of pulse-width adjustable control signal; the two output ends of the control module are connected to the adjustable ends of the two variable resistance modules in one-to-one correspondence.

3. The color temperature adjustable light-emitting device according to claim 2, wherein: The color temperature adjustment module includes a first control end, a second control end, a first positive terminal, a second positive terminal, and a negative terminal; the first control end is the adjustable end of the one variable resistance module, and the first positive terminal is the positive terminal of the one variable resistance module; The second control end is the adjustable end of the other variable resistance module, and the second positive terminal is the positive terminal of the other variable resistance module; the negative terminal is the negative terminal of the two variable resistance modules; The first control end is connected to an output end of the control module, and the second control end is connected to the other output end of the control module; the first positive terminal is connected to the negative electrode of the first light-emitting component, and the second positive terminal is connected to the negative electrode of the second light-emitting component; the negative terminal is used to be connected to the negative electrode of a power supply; the positive electrode of the first light-emitting component is used to be connected to the positive electrode of the power supply, and the positive electrode of the second light-emitting component is used to be connected to the positive electrode of the power supply.

4. The color temperature adjustable light emitting device according to claim 1, wherein: The color temperature adjustment module further includes a voltage division module; the voltage division module is connected in parallel with the variable resistor module, and the output end of the voltage division module is connected to the adjustable end of the other variable resistor module; the adjustable end of the variable resistor module is connected to the output end of the control module.

5. The color temperature adjustable light emitting device according to claim 4, characterized in that: The color temperature adjustment module includes a first control end, a first positive end, a second positive end, and a negative end; the first control end is the adjustable end of the variable resistor module, and the first positive end is the positive end of the variable resistor module; the negative end is the negative ends of the two variable resistor modules; The first control end is connected to the output end of the control module; the first positive end is connected to the negative pole of the first light-emitting component, and the second positive end is connected to the negative pole of the second light-emitting component; the negative end is used to be connected to the negative pole of a power supply; the positive pole of the first light-emitting component is used to be connected to the positive pole of the power supply, and the positive pole of the second light-emitting component is used to be connected to the positive pole of the power supply.

6. The color temperature adjustable lighting device according to claim 1, wherein: The first light-emitting component includes a group of LED circuits; the second light-emitting component includes a group of LED circuits; the color temperatures of the first light-emitting component and the second light-emitting component are different.

7. The color temperature adjustable light emitting device according to claim 1, characterized in that: The control module outputs a pulse-width adjustable control signal with a duty cycle of δ to control the equivalent output resistance of the variable resistor module in the color temperature adjustment module to be VR: Wherein, when the variable resistor module is powered by a constant current source, the current flowing through the variable resistor module is constantly I; When the variable resistor module receives the high level of the pulse-width adjustable control signal, the MOS transistor in the variable resistor module is turned on, and the equivalent resistance between the positive and negative terminals of the variable resistor module is the parallel connection of the first resistor RA and the second resistor RB, that is, the resistance value of the equivalent resistance is At this time, the voltage between the positive and negative terminals of the variable resistor module is U' = I·R'; When the variable resistor module receives the low level of the pulse-width adjustable control signal, the MOS tube in the variable resistor module is turned off, and only the first resistor RA conducts between the positive end and the negative end of the variable resistor module. At this time, the voltage between the positive end and the negative end of the variable resistor module is U” = I·RA; The average voltage between the positive end and the negative end of the variable resistor module within the entire PWM cycle is: Within the entire PWM cycle, the average resistance value between the positive end and the negative end of the variable resistor module is the equivalent output resistance VR of the variable resistor module.

8. The color temperature adjustable light emitting device according to claim 1, wherein: The control module outputs a pulse-width adjustable control signal with a duty cycle of δ to control the equivalent output resistance of the variable resistor module in the color temperature adjustment module to be VR: Wherein, when the variable resistor module is powered by a constant voltage source, the voltage between the positive end and the negative end of the variable resistor module is constantly U; When the variable resistor module receives the high level of the pulse width adjustable control signal, the current flowing into the positive and negative terminals of the variable resistor module is When the variable resistor module receives the low level of the pulse width adjustable control signal, the current flowing into the positive and negative terminals of the variable resistor module is Within the entire PWM cycle, the average value of the current flowing into the positive end and the negative end of the variable resistor module is: Within the entire PWM cycle, the average resistance value between the positive end and the negative end of the variable resistor module is the equivalent output resistance VR of the variable resistor module.

9. An LED device, characterized in that, The LED device includes the color temperature adjustable light-emitting device according to any one of claims 1 to 8.

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