A dimming control method and a dimming circuit

Abstract

The application discloses a dimming control method and a dimming circuit, which comprise a constant-voltage dimming module and a constant-current dimming module, and comprises the following steps: step 1, a constant voltage VA is obtained to supply power to the constant-voltage dimming module; step 2, a first control signal is obtained to control the constant-voltage dimming module to output a voltage VB with adjustable size; step 3, the voltage VB supplies power to the constant-current dimming module; step 4, a second control signal is separated from the voltage VB; and step 5, the control end of the constant-current dimming module inputs the second control signal, so that the constant-current dimming module outputs a current with adjustable size. The dimming control method does not need to additionally input a control signal, but separates the second control signal from the output voltage VB of the constant-voltage dimming module to control the size of the output current of the constant-current dimming module, so that the constant-voltage LED load and the constant-current LED load can be dimmed simultaneously.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of LED dimming technology, and particularly to a dimming control method and a dimming circuit. BACKGROUND

[0002] Constant voltage dimming has good dimming characteristics. Currently, constant voltage power supplies with dimming functions are mainly used in combination with constant voltage type LED loads (LED driving requires stable current, and since the voltage is constant, only a certain resistance value needs to be connected in series on the LED lamp to maintain the current) to achieve constant voltage dimming. This dimming method is achieved by controlling the constant voltage power supply to dim the constant voltage type LED load. However, this method requires a constant voltage type LED load and cannot achieve constant voltage dimming of constant current type LED loads (LED lamps without series resistance). In order to achieve dimming of constant current type LED loads by constant voltage power supplies, the prior art uses constant voltage power supplies without dimming functions to connect DC / DC constant current dimming modules and then connect corresponding constant current type LED loads. This dimming method is achieved by adjusting the DC / DC dimming module to dim the constant current type LED load. In this way, one DC / DC dimming module is connected to one LED load. If multiple LED loads need to be dimmed, additional control lines need to be connected to multiple DC / DC dimming modules, making the circuit complex and increasing the difficulty of installation and debugging. SUMMARY

[0003] The present application aims to at least solve one of the technical problems in the prior art, and provides a dimming control method and a dimming circuit that are suitable for constant voltage type LED loads and constant current type LED loads and are easy to control.

[0004] The dimming control method according to the first aspect of the present application includes a constant voltage dimming module and a constant current dimming module, and includes the following steps:

[0005] Step 1: Obtain a constant voltage VA to power the constant voltage dimming module;

[0006] Step 2: Obtain a first control signal to control the constant voltage dimming module to output a voltage VB of adjustable size;

[0007] Step 3: The voltage VB powers the constant current dimming module;

[0008] Step 4: Separate a second control signal from the voltage VB;

[0009] Step 5: The control end of the constant current dimming module inputs the second control signal, so that the constant current dimming module outputs a current of adjustable size.

[0010] The dimming circuit according to the second aspect of the present application, applying the dimming control method, comprises a dimming signal module, a constant voltage output module, and a signal separation circuit, the dimming signal module is capable of outputting the first control signal, the constant voltage output module outputs a constant voltage VA, the signal separation circuit is capable of separating the second control signal from the voltage VB, the output end of the constant voltage dimming module is electrically connected with a constant voltage type LED load, the input end of the signal separation circuit, and the input end of the constant current dimming module, the output end of the signal separation circuit is electrically connected with the constant current dimming module to control the output current of the constant current dimming module through the second control signal, and the output end of the constant current dimming module is electrically connected with a constant current type LED load.

[0011] The dimming circuit according to the second aspect of the present application, the signal separation circuit comprises a photo-coupler U2 and a switch tube Q3, the positive input end of the photo-coupler U2 is electrically connected with the positive output end of the constant voltage dimming module through a series resistor, the negative input end of the photo-coupler U2 is electrically connected with the negative output end of the constant voltage dimming module, the negative output end of the photo-coupler U2 is electrically connected with the first end of the switch tube Q3, the second end of the switch tube Q3 is electrically connected with the constant current dimming module, and the third end of the switch tube Q3 is grounded.

[0012] The dimming circuit according to the second aspect of the present application, the signal separation circuit comprises a switch tube Q4 and a switch tube Q5, the first end of the switch tube Q4 is electrically connected with the positive output end of the constant voltage dimming module through a series resistor, the second end of the switch tube Q4 is electrically connected with the first end of the switch tube Q3, the second end of the switch tube Q5 is electrically connected with the constant current dimming module, and the third end of the switch tube Q5 and the third end of the switch tube Q4 are grounded respectively.

[0013] The dimming circuit according to the second aspect of the present application, the signal separation circuit comprises a switch tube Q6, a switch tube Q7, and a switch tube Q8, the first end of the switch tube Q6 is electrically connected with the positive output end of the constant voltage dimming module through a series resistor, the second end of the switch tube Q6 is electrically connected with the negative output end of the constant voltage dimming module, the third end of the switch tube Q6 is electrically connected with the second end of the switch tube Q7, the third end of the switch tube Q7 is electrically connected with the first end of the switch tube Q8, the second end of the switch tube Q8 is electrically connected with the constant current dimming module, and the third end of the switch tube Q8 and the third end of the switch tube Q7 are grounded respectively.

[0014] The constant-voltage dimming module comprises a first power supply circuit, a first constant-voltage dimming chip and a switch tube Q1, the control end of the first constant-voltage dimming chip inputs the first control signal, the power supply end of the first constant-voltage dimming chip is electrically connected with one end of the first power supply circuit, the other end of the first power supply circuit is electrically connected with the positive output end of the constant-voltage output module, the drive output end of the first constant-voltage dimming chip is electrically connected with the first end of the switch tube Q1, the second end of the switch tube Q1 is electrically connected with the negative output end of the constant-voltage output module, and the third end of the switch tube Q1 is the negative output end of the constant-voltage dimming module.

[0015] The constant-voltage dimming module comprises a first power supply circuit, a first constant-voltage dimming chip and a switch tube Q1, the control end of the first constant-voltage dimming chip inputs the first control signal, the power supply end of the first constant-voltage dimming chip is electrically connected with one end of the first power supply circuit, the other end of the first power supply circuit is electrically connected with the positive output end of the constant-voltage output module, the drive output end of the first constant-voltage dimming chip is electrically connected with the first end of the switch tube Q1, the second end of the switch tube Q1 is electrically connected with the negative output end of the constant-voltage output module, and the third end of the switch tube Q1 is the negative output end of the constant-voltage dimming module.

[0016] The constant-voltage dimming module comprises a first power supply circuit, a first constant-voltage dimming chip and a switch tube Q1, the control end of the first constant-voltage dimming chip inputs the first control signal, the power supply end of the first constant-voltage dimming chip is electrically connected with one end of the first power supply circuit, the other end of the first power supply circuit is electrically connected with the positive output end of the constant-voltage output module, the drive output end of the first constant-voltage dimming chip is electrically connected with the first end of the switch tube Q1, the second end of the switch tube Q1 is electrically connected with the negative output end of the constant-voltage output module, and the third end of the switch tube Q1 is the negative output end of the constant-voltage dimming module.

[0017] The constant-voltage dimming module comprises a first power supply circuit, a first constant-voltage dimming chip and a switch tube Q1, the control end of the first constant-voltage dimming chip inputs the first control signal, the power supply end of the first constant-voltage dimming chip is electrically connected with one end of the first power supply circuit, the other end of the first power supply circuit is electrically connected with the positive output end of the constant-voltage output module, the drive output end of the first constant-voltage dimming chip is electrically connected with the first end of the switch tube Q1, the second end of the switch tube Q1 is electrically connected with the negative output end of the constant-voltage output module, and the third end of the switch tube Q1 is the negative output end of the constant-voltage dimming module.

[0018] The constant-voltage dimming module comprises a first power supply circuit, a first constant-voltage dimming chip and a switch tube Q1, the control end of the first constant-voltage dimming chip inputs the first control signal, the power supply end of the first constant-voltage dimming chip is electrically connected with one end of the first power supply circuit, the other end of the first power supply circuit is electrically connected with the positive output end of the constant-voltage output module, the drive output end of the first constant-voltage dimming chip is electrically connected with the first end of the switch tube Q1, the second end of the switch tube Q1 is electrically connected with the negative output end of the constant-voltage output module, and the third end of the switch tube Q1 is the negative output end of the constant-voltage dimming module.

[0019] The light adjusting control method and the light adjusting circuit have at least the following beneficial effects: the input end of the constant-voltage light adjusting module inputs constant voltage VA, the control end of the constant-voltage light adjusting module inputs the first control signal, so that the constant-voltage light adjusting module outputs voltage VB of adjustable size, the voltage VB can directly drive the constant-voltage type LED load to realize constant-voltage light adjustment; meanwhile, the second control signal is separated from the output voltage VB of the constant-voltage light adjusting module to control the size of the output current of the constant-current light adjusting module, the output end of the constant-current light adjusting module is electrically connected with both ends of the constant-current type LED load, so that the light adjustment of the constant-current type LED load is realized; that is, no additional control line needs to be connected to realize the light adjustment of the constant-current type LED load, the circuit is simplified, and the light adjustment of the constant-voltage type LED load and the constant-current type LED load can be realized simultaneously under one constant-voltage output module, one constant-voltage light adjusting module and one light adjusting signal module.

[0020] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0021] The specific embodiments of the application will be further described below with reference to the drawings;

[0022] Figure 1 is a principle block diagram of the light adjusting circuit;

[0023] Figure 2 is a principle block diagram of the signal separation circuit and the constant-current light adjusting module in the light adjusting circuit;

[0024] Figure 3 is a circuit principle diagram of one of the constant-voltage light adjusting modules in the light adjusting circuit;

[0025] Figure 4 is a circuit principle diagram of another of the constant-voltage light adjusting modules in the light adjusting circuit;

[0026] Figure 5 is a circuit principle diagram of one of the signal separation circuits;

[0027] Figure 6 is a circuit principle diagram of another of the signal separation circuits;

[0028] Figure 7 is a circuit principle diagram of another of the signal separation circuits;

[0029] Figure 8 is a circuit principle diagram of another of the signal separation circuits;

[0030] Figure 9 is a circuit principle diagram of the signal separation circuit and the constant-current light adjusting module. DETAILED DESCRIPTION

[0031] The specific embodiments of the present application will be described in detail in this part, the preferred embodiments of the present application are shown in the drawings, the role of the drawings is to supplement the description of the text part with figures, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the present application, but it cannot be understood as a limitation on the protection scope of the present application.

[0032] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right and the like, is based on the orientation or position relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application.

[0033] In the description of the present application, several meanings are one or more, the meaning of multiple is more than two, greater than, less than, more than and the like are not included in the number, above, below, within and the like are included in the number. If it is described as first, second, it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0034] The present application discloses a dimming control method, comprising a constant voltage dimming module 10 and a constant current dimming module 22, comprising the steps of:

[0035] Step 1, obtaining a constant voltage VA to power the constant voltage dimming module 10;

[0036] Step 2, obtaining a first control signal to control the constant voltage dimming module 10 to output a size-adjustable voltage VB;

[0037] Step 3, the voltage VB powers the constant current dimming module 22;

[0038] Step 4, separating a second control signal from the voltage VB;

[0039] Step 5, inputting the second control signal to the control end of the constant current dimming module 22, so that the constant current dimming module 22 outputs a size-adjustable current.

[0040] The dimming control method does not need to additionally access the control signal, but separates the second control signal from the output voltage VB of the constant voltage dimming module 10 to control the size of the output current of the constant current dimming module 22, so as to simultaneously dim the constant voltage type LED load and the constant current type LED load.

[0041] Reference Figures 1 to 9The application further discloses a dimming circuit applying the dimming control method, which comprises a constant-voltage dimming module 10, a signal separation circuit 21, a constant-current dimming module 22, a dimming signal module and a constant-voltage output module, the dimming signal module can output the first control signal, the constant-voltage output module outputs a constant voltage VA, the input end of the constant-voltage dimming module 10 inputs the constant voltage VA, the control end of the constant-voltage dimming module 10 inputs the first control signal, the first control signal is a first PWM signal, the dimming signal module comprises but is not limited to a DALI dimming circuit, a wireless dimming circuit, a 0 / 1-10V analog dimming circuit and a PUSH dimming circuit. The first control signal controls the constant-voltage dimming module 10 to output a voltage VB with adjustable size, the output end of the constant-voltage dimming module 10 is electrically connected with a constant-voltage type LED load and the input end of the signal separation circuit 21, the signal separation circuit 21 can separate a second control signal from the voltage VB, the second control signal is a second PWM signal, the output end of the signal separation circuit 21 is electrically connected with the constant-current dimming module 22 to control the output current of the constant-current dimming module 22 through the second control signal, and the output end of the constant-current dimming module 22 is electrically connected with a constant-current type LED load. The constant-voltage dimming module 10 can be directly electrically connected with both ends of the constant-voltage type LED load to realize constant-voltage dimming; meanwhile, the signal separation circuit 21 can separate the second control signal from the output voltage VB of the constant-voltage dimming module 10 to control the output current of the constant-current dimming module 22, the output end of the constant-current dimming module 22 is electrically connected with both ends of the constant-current type LED load, so that the constant-current type LED load is dimmed; that is, an additional control line is not needed to dim the constant-current type LED load, the circuit is simplified, and the dimming of the constant-voltage type LED load and the constant-current type LED load can be realized simultaneously under one constant-voltage output module, one constant-voltage dimming module and one dimming signal module.

[0042] As Figure 3 and Figure 4 are two kinds of component modes of the constant-voltage dimming module 10. Figure 3 In the mode shown in FIG. 1, the constant-voltage dimming module 10 comprises a first power supply circuit, a first constant-voltage dimming chip U1 and a switch tube Q1, wherein the first power supply circuit and the first constant-voltage dimming chip U1 are both existing technologies, the first power supply circuit is used for step-down voltage output by the constant-voltage output module to supply power to the first constant-voltage dimming chip U1, the control end of the first constant-voltage dimming chip U1 inputs the first control signal, the driving output end of the first constant-voltage dimming chip U1 is electrically connected with the first end of the switch tube Q1, the second end of the switch tube Q1 is electrically connected with the negative output end of the constant-voltage output module, and the third end of the switch tube Q1 is the negative output end of the constant-voltage dimming module 10; that is, the dimming switch tube Q1 is on the negative line in the main circuit.

[0043] Figure 4In the constant-voltage dimming module 10, the second power supply circuit, the second constant-voltage dimming chip U1 and the switch tube Q2 are adopted, wherein the second power supply circuit and the second constant-voltage dimming chip U1 are both adopted in the prior art, the second power supply circuit is used to step down the voltage output by the constant-voltage output module to supply power to the second constant-voltage dimming chip U1, the control end of the second constant-voltage dimming chip U1 inputs the first control signal, the driving output end of the second constant-voltage dimming chip U1 is electrically connected with the first end of the switch tube Q2, the second end of the switch tube Q2 is electrically connected with the positive output end of the constant-voltage output module, and the third end of the switch tube Q2 is the positive output end of the constant-voltage dimming module 10, that is, the dimming switch tube Q2 is arranged on the positive line in the main circuit.

[0044] Figure 3 and Figure 4 The main working principle of the constant-voltage dimming module 10 in the constant-voltage dimming module 10 is that the constant-voltage output module outputs a stable direct-current voltage VA to directly supply the constant-voltage dimming module 10, and the switch tube Q1 and the switch tube Q2 in the constant-voltage dimming module 10 are controlled by the first control signal output by the dimming signal module; the dimming signal module outputs a corresponding PWM pulse width according to the size of the dimming required. The switch tube Q1 and the switch tube Q2 change the direct-current voltage VA into a voltage VB according to the duty ratio of the first control signal, and the effective value of the voltage VB changes with the change of the duty ratio of the first control signal. If the changed voltage VB is directly connected to the constant-voltage type LED load (LED lamp with a series resistor), the brightness of the LED lamp will also change, thereby realizing the dimming of the constant-voltage type LED load.

[0045] As Figure 2 , Figures 5 to 8 , the signal separation circuit 21, the constant-current dimming module 22, the rectifier circuit 24 and the third power supply circuit 23 are adopted, wherein the third power supply circuit 23 and the rectifier circuit 24 are both adopted in the prior art, the third power supply circuit 23 steps down the voltage after rectification to supply power to the signal separation circuit 21. The input end of the rectifier circuit 24 is electrically connected with the output end of the constant-voltage dimming module 10, one end of the third power supply circuit 23 is electrically connected with the rectifier circuit 24, the other end of the third power supply circuit 23 is electrically connected with the signal separation circuit 21 to provide a working voltage for the signal separation circuit 21, the signal separation circuit 21 can separate the second control signal from the voltage VB, the output end of the signal separation circuit 21 is electrically connected with the constant-current dimming module 22 to control the output current of the constant-current dimming module 22 through the second control signal, and the output end of the constant-current dimming module 22 is electrically connected with the constant-current type LED load, thereby realizing the dimming of the constant-current type LED load.

[0046] As Figure 5As shown in the figure, in some embodiments, the signal separation circuit 21 comprises a photo-coupler U2 and a switch tube Q3, the positive input end of the photo-coupler U2 is electrically connected with the positive output end of the constant-voltage dimming module 10 through a series resistor, the negative input end of the photo-coupler U2 is electrically connected with the negative output end of the constant-voltage dimming module 10, the negative output end of the photo-coupler U2 is electrically connected with the first end of the switch tube Q3, the second end of the switch tube Q3 is electrically connected with the third power supply circuit 23 and the constant-current dimming module 22 respectively, and the third end of the switch tube Q3 is grounded. That is, the second control signal with a certain duty ratio is separated from the voltage VB through the on-off of the photo-coupler U2 and the switch tube Q3.

[0047] As shown in the figure, Figure 6 in some embodiments, the signal separation circuit 21 comprises a switch tube Q4 and a switch tube Q5, the first end of the switch tube Q4 is electrically connected with the positive output end of the constant-voltage dimming module 10 through a series resistor, the second end of the switch tube Q4 is electrically connected with the first end of the switch tube Q3 and the third power supply circuit 23 respectively, the second end of the switch tube Q5 is electrically connected with the third power supply circuit 23 and the constant-current dimming module 22 respectively, and the third end of the switch tube Q5 and the third end of the switch tube Q4 are grounded respectively. That is, the second control signal with a certain duty ratio is separated from the voltage VB through the on-off of the switch tube Q4 and the switch tube Q5.

[0048] As shown in the figure, Figure 7 in some embodiments, the signal separation circuit 21 comprises a switch tube Q6, a switch tube Q7 and a switch tube Q8, the first end of the switch tube Q6 is electrically connected with the positive output end of the constant-voltage dimming module 10 through a series resistor, the second end of the switch tube Q6 is electrically connected with the negative output end of the constant-voltage dimming module 10, the third end of the switch tube Q6 is electrically connected with the second end of the switch tube Q7, the third end of the switch tube Q7 is electrically connected with the third power supply circuit 23 and the first end of the switch tube Q8 respectively, the second end of the switch tube Q8 is electrically connected with the third power supply circuit 23 and the constant-current dimming module 22 respectively, and the third end of the switch tube Q8 and the third end of the switch tube Q7 are grounded respectively. That is, the second control signal with a certain duty ratio is separated from the voltage VB through the on-off of the switch tube Q6, the switch tube Q7 and the switch tube Q8.

[0049] As shown in the figure, Figure 8 in some embodiments, the signal separation circuit 21 is integrated in the single-chip microcomputer U3, and the circuit in the single-chip microcomputer U3 can adopt the circuit structure in the above Figures 5 to 7 , which is highly integrated.

[0050] As shown in the figure, Figure 2As shown, in some embodiments, the constant current dimming module 22 comprises a DC-DC constant current circuit 221 and a dimming circuit, wherein the topology of the DC-DC constant current circuit 221 can be composed of a buck (BUCK) or a boost (BOOST) structure, and the dimming circuit adopts an existing dimming driving circuit. The input end of the DC-DC constant current circuit 221 is electrically connected with the output end of the rectifier circuit 24, one end of the dimming circuit inputs the second control signal, the output end of the dimming circuit is electrically connected with the DC-DC constant current circuit 221 to control the size of the output current of the DC-DC constant current circuit 221, and the output end of the DC-DC constant current circuit 221 is electrically connected with both ends of the constant current type LED load. As shown in the figure, Figure 9 As shown, the dimming circuit adopts a dimming control chip U4, the DC-DC constant current circuit 221 adopts a BUCK bucking topology, the rectifier circuit 24 is a diode D1, and the third power supply circuit 23 comprises a transistor Q9, resistors and a zener diode to form a bucking circuit.

[0051] As shown, Figures 5 to 8 In some embodiments, the constant current dimming module 22 adopts a constant current dimming chip integrated with the DC-DC constant current circuit 221 and the dimming circuit, which is a prior art and will not be described in detail here.

[0052] As shown, Figure 9 In some embodiments, a multi-section current control circuit 30 is further included, which is electrically connected with the constant current dimming module 22 to control the output of multi-section current, and the multi-section current control circuit 30 comprises a code dialing circuit and an NFC circuit.

[0053] It is easy for those skilled in the art to understand that the above preferred modes can be freely combined and superimposed without conflict.

[0054] The above is only the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made according to the content of the present application specification and drawings, or direct or indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A dimming control method, comprising a constant voltage dimming module (10) and a constant current dimming module (22), characterized in that: Including steps: Step 1, obtaining a constant voltage VA to power the constant voltage dimming module (10); Step 2, obtaining a first control signal to control the constant voltage dimming module (10) to output an adjustable voltage VB; Step 3, the voltage VB supplies power to the constant current dimming module (22); Step 4, separating the second control signal from the voltage VB; Step 5: the control end of the constant current dimming module (22) inputs the second control signal, so that the constant current dimming module (22) outputs a current with adjustable magnitude; The dimming signal module is capable of outputting the first control signal, the constant voltage output module outputs the constant voltage VA, the signal separation circuit (21) is capable of separating the second control signal from the voltage VB, the output end of the constant voltage dimming module (10) is electrically connected to the constant voltage LED load, the input end of the signal separation circuit (21) and the input end of the constant current dimming module (22), respectively, the output end of the signal separation circuit (21) is electrically connected to the constant current dimming module (22) to control the output current of the constant current dimming module (22) through the second control signal, and the output end of the constant current dimming module (22) is electrically connected to the constant current LED load.

2. A dimming circuit, applying the dimming control method according to claim 1, characterized in that: The invention comprises a dimming signal module, a constant voltage output module, and a signal separation circuit (21), wherein the dimming signal module is capable of outputting the first control signal, the constant voltage output module outputs a constant voltage VA, the signal separation circuit (21) is capable of separating a second control signal from the voltage VB, the output end of the constant voltage dimming module (10) is electrically connected to a constant voltage type LED load, the input end of the signal separation circuit (21), and the input end of the constant current dimming module (22), respectively, the output end of the signal separation circuit (21) is electrically connected to the constant current dimming module (22) to control the magnitude of the output current of the constant current dimming module (22) through the second control signal, and the output end of the constant current dimming module (22) is electrically connected to the constant current type LED load.

3. The dimming circuit according to claim 2, wherein: The signal separation circuit (21) includes an optocoupler U2 and a switch tube Q3, wherein the positive input end of the optocoupler U2 is electrically connected to the positive output end of the constant voltage dimming module (10) via a series resistor, the negative input end of the optocoupler U2 is electrically connected to the negative output end of the constant voltage dimming module (10), the negative output end of the optocoupler U2 is electrically connected to the first end of the switch tube Q3, the second end of the switch tube Q3 is electrically connected to the constant current dimming module (22), and the third end of the switch tube Q3 is grounded.

4. The dimming circuit according to claim 2, wherein: The signal separation circuit (21) includes a switch tube Q4 and a switch tube Q5, wherein the first end of the switch tube Q4 is electrically connected to the positive output end of the constant voltage dimming module (10) via a series resistor, the second end of the switch tube Q4 is electrically connected to the first end of the switch tube Q3, the second end of the switch tube Q5 is electrically connected to the constant current dimming module (22), and the third end of the switch tube Q5 and the third end of the switch tube Q4 are grounded respectively.

5. The dimming circuit according to claim 2, wherein: The signal separation circuit (21) includes a switch tube Q6, a switch tube Q7, and a switch tube Q8. The first end of the switch tube Q6 is electrically connected to the positive output end of the constant voltage dimming module (10) via a series resistor, the second end of the switch tube Q6 is electrically connected to the negative output end of the constant voltage dimming module (10), the third end of the switch tube Q6 is electrically connected to the second end of the switch tube Q7, the third end of the switch tube Q7 is electrically connected to the first end of the switch tube Q8, the second end of the switch tube Q8 is electrically connected to the constant current dimming module (22), and the third end of the switch tube Q8 and the third end of the switch tube Q7 are grounded respectively.

6. The dimming circuit according to claim 2, wherein: The constant current dimming module (22) comprises a DC-to-DC constant current circuit (221) and a dimming circuit; the input end of the DC-to-DC constant current circuit (221) is electrically connected to the output end of the constant voltage dimming module (10); one end of the dimming circuit inputs the second control signal; the output end of the dimming circuit is electrically connected to the DC-to-DC constant current circuit (221) to control the magnitude of the output current of the DC-to-DC constant current circuit (221); and the output end of the DC-to-DC constant current circuit (221) is electrically connected to both ends of a constant current type LED load.

7. The dimming circuit according to claim 2, wherein: The constant voltage dimming module (10) comprises a first power supply circuit, a first constant voltage dimming chip and a switch tube Q1; the control end of the first constant voltage dimming chip inputs the first control signal; the power supply end of the first constant voltage dimming chip is electrically connected to one end of the first power supply circuit; the other end of the first power supply circuit is electrically connected to the positive output end of the constant voltage output module; the driving output end of the first constant voltage dimming chip is electrically connected to the first end of the switch tube Q1; the second end of the switch tube Q1 is electrically connected to the negative output end of the constant voltage output module; and the third end of the switch tube Q1 is the negative output end of the constant voltage dimming module (10).

8. The dimming circuit according to claim 2, wherein: The constant voltage dimming module (10) comprises a second power supply circuit, a second constant voltage dimming chip and a switch tube Q2, the control end of the second constant voltage dimming chip inputs the first control signal, the power supply end of the second constant voltage dimming chip is electrically connected to one end of the second power supply circuit, the other end of the second power supply circuit is electrically connected to the positive output end of the constant voltage output module, the driving output end of the second constant voltage dimming chip is electrically connected to the first end of the switch tube Q2, the second end of the switch tube Q2 is electrically connected to the positive output end of the constant voltage output module, and the third end of the switch tube Q2 is the positive output end of the constant voltage dimming module (10).

9. The dimming circuit according to claim 2, wherein: It also includes a multi-segment current control circuit (30), which is electrically connected to the constant current dimming module (22) to control the output of multiple currents, and includes a dial circuit and an NFC circuit.

10. The dimming circuit according to claim 2, wherein: The dimming signal module includes a DALI dimming circuit, a wireless dimming circuit, a 0 / 1-10V analog dimming circuit or a PUSH dimming circuit.

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