LED drive circuit and lamp

Abstract

The utility model provides an LED drive circuit and a lamp. The LED driving circuit comprises a constant current driving module, a current control module, a first number of switching tubes and a first number of sampling modules, for any switch tube, the switch tube, the sampling module corresponding to the switch tube and the LED lamp string corresponding to the switch tube are connected in series between the output end of the constant current driving module and the first grounding end. The last path of LED lamp string is connected in series between the output end of the constant-current driving module and the first grounding end; the input end of the constant-current driving module is connected with a power supply, and the control end of the constant-current driving module is used for receiving a dimming signal; the current control module is connected with the output end of each sampling module and is used for receiving a color modulation signal and a light modulation signal and sending a control signal to each switching tube. According to the invention, the switching tubes are arranged in the N-1 street lamp strings, and the current of the N-1 street lamp strings is sampled, so that the current of each street lamp string can be accurately controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of LEDs, and in particular to an LED driving circuit and a lamp. Background Art

[0002] The color adjustment circuit of the existing LED light source usually uses an MCU for color adjustment control or a series resistor for color adjustment control. The color tolerance of the product is greatly limited by the junction voltage of each LED light source. Therefore, the junction voltage of the LED light source (the current flowing through the LED light source) needs to be strictly limited.

[0003] In the prior art, the color adjustment circuit in the lamp cannot accurately control the current flowing through each LED light source, and thus cannot accurately control the color tolerance of the product. Utility Model Content

[0004] The embodiments of the utility model provide an LED driving circuit and a lamp to solve the problem in the prior art that the current of each LED light source cannot be accurately controlled, thereby affecting the color tolerance of the product.

[0005] In a first aspect, an embodiment of the utility model provides an LED driving circuit for driving at least two LED light strings to emit light; the LED driving circuit comprises: a constant current driving module, a current control module, a first number of switch tubes, and a first number of sampling modules; wherein the first number is one less than the number of LED light strings;

[0006] For any switch tube, the switch tube, the sampling module corresponding to the switch tube, and the LED light string corresponding to the switch tube are connected in series between the output end of the constant current driving module and the first ground end;

[0007] The last LED light string is connected in series between the output end of the constant current driving module and the first grounding end;

[0008] The input end of the constant current driving module is connected to the power supply, and the control end of the constant current driving module is used to receive the dimming signal;

[0009] The current control module is connected to the output end of each sampling module respectively, and receives the current of each LED light string sampled by each sampling module;

[0010] The current control module is also used to receive a color adjustment signal and a dimming signal, and send a control signal to each switch tube according to the dimming signal, the color adjustment signal and the current of each LED light string obtained by sampling.

[0011] Optionally, for any sampling module, the first end of the sampling module is connected to the first ground end; the switch tube corresponding to the sampling module and the LED light string corresponding to the sampling module are connected in series between the second end of the sampling module and the output end of the constant current driving module; the sampling module includes: a first resistor;

[0012] The first end of the first resistor is connected to the first end of the sampling module, and the second end of the first resistor is connected to the second end of the sampling module and the output end of the sampling module respectively.

[0013] Optionally, the LED driving circuit further includes: a color adjustment module;

[0014] The output end of the color adjustment module is used to output a color adjustment signal.

[0015] Optionally, the color adjustment module includes: a gear selection unit, a second resistor and a first capacitor;

[0016] The first end of the gear selection unit is connected to the first end of the second resistor, the first end of the first capacitor and the output end of the color adjustment module respectively, and the second end of the gear selection unit is connected to the first ground end;

[0017] The second end of the second resistor is connected to the first DC power supply; the second end of the first capacitor is connected to the first ground terminal;

[0018] Wherein, when in different gears, the resistance between the first end and the second end of the gear selection unit is different.

[0019] Optionally, the gear selection unit includes: a multi-gear selection switch and a plurality of third resistors; wherein the resistance value of each third resistor is different;

[0020] The movable end of the multi-speed selection switch is connected to the second end of the gear selection unit, and each fixed end of the multi-speed selection switch is connected to the first end of the gear selection unit through a corresponding third resistor.

[0021] Optionally, the LED driving circuit further includes: a dimming module;

[0022] The output end of the dimming module is used to output a dimming signal.

[0023] Optionally, the dimming signal is a PWM signal; the dimming module includes: a dimming unit, a PWM generation unit and an isolation unit;

[0024] The output end of the dimming unit is connected to the input end of the PWM generation unit, and the output end of the PWM generation unit is connected to the input end of the isolation unit;

[0025] The output end of the isolation unit is used to output a dimming signal.

[0026] Optionally, the dimming unit includes: a current source, a dimming input subunit, a first voltage regulator diode, a first diode, a second capacitor, a fourth resistor, a fifth resistor and a sixth resistor;

[0027] The anode of the first zener diode is connected to the second ground terminal, the cathode of the first zener diode is connected to the output terminal of the current source, the cathode of the first zener diode is also connected to the first end of the fifth resistor, the first end of the second capacitor and the output terminal of the dimming unit through the fourth resistor, and the cathode of the first zener diode is also connected to the anode of the first diode through the sixth resistor;

[0028] A first end of the dimming input subunit is connected to the cathode of the first diode, and a second end of the dimming input subunit is connected to the second ground end;

[0029] The second end of the fifth resistor and the second end of the second capacitor are both connected to the second ground terminal;

[0030] Among them, when in different gears, the resistance of the dimming input subunit is different, so that the voltage at the output end of the dimming unit is different.

[0031] Optionally, the power supply is an AC power supply; the constant current drive module includes: a rectifier unit and a constant current drive unit;

[0032] The input end of the rectifier unit is connected to the input end of the constant current drive module, and the output end of the rectifier unit is connected to the input end of the constant current drive unit;

[0033] The control end of the constant current driving unit is connected to the control end of the constant current driving module, and the output end of the constant current driving unit is connected to the output end of the constant current driving module.

[0034] In a second aspect, an embodiment of the utility model provides a lamp, comprising the LED driving circuit provided in the first aspect of the above embodiment.

[0035] The embodiment of the utility model provides an LED driving circuit and a lamp. The LED driving circuit is used to drive at least two LED light strings to emit light; the LED driving circuit includes: a constant current driving module, a current control module, a first number of switch tubes, and a first number of sampling modules; wherein the first number is one less than the number of LED light strings; for any switch tube, the switch tube and the sampling module corresponding to the switch tube and the LED light string corresponding to the switch tube are connected in series between the output end of the constant current driving module and the first grounding terminal; the last LED light string is connected in series between the output end of the constant current driving module and the first grounding terminal; the input end of the constant current driving module is connected to the power supply, and the control end of the constant current driving module is used to receive a dimming signal; the current control module is respectively connected to the output end of each sampling module to receive the current of each LED light string sampled by each sampling module; the current control module is also used to receive a color adjustment signal and a dimming signal, and send a control signal to each switch tube according to the dimming signal, the color adjustment signal and the current of each LED light string sampled. In the embodiment of the utility model, since the total current of the constant current driving module is constant, it is only necessary to set a switch tube in the path of the N-1 LED light strings and sample the current of the N-1 LED light strings. The current control module accurately controls the current of each LED light string according to the total current and the feedback value of each LED light string, so that the current flowing through each LED light string can be accurately controlled, and the color tolerance of the product can be accurately controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0037] Figure 1 This is a circuit structure diagram of an LED driving circuit provided by an embodiment of the utility model;

[0038] Figure 2 This is a partial circuit structure diagram of another LED driving circuit provided by an embodiment of the utility model;

[0039] Figure 3 This is a partial circuit structure diagram of another LED driving circuit provided by an embodiment of the utility model;

[0040] Figure 4 This is a schematic diagram of the circuit structure of a color adjustment module provided by an embodiment of the utility model;

[0041] Figure 5This is a circuit schematic diagram of a gear selection unit provided in an embodiment of the utility model;

[0042] Figure 6 This is a schematic diagram of the circuit structure of a dimming module provided by an embodiment of the utility model;

[0043] Figure 7 This is a circuit schematic diagram of a dimming unit provided in an embodiment of the utility model;

[0044] Figure 8 This is a circuit schematic diagram of a dimming module provided by an embodiment of the utility model;

[0045] Fig. 9 This is a schematic diagram of the circuit structure of a constant current drive module provided by an embodiment of the utility model;

[0046] Fig.10 This is a circuit schematic diagram of a rectifier unit provided in an embodiment of the utility model;

[0047] Fig.11 This is a circuit schematic diagram of a constant current drive unit provided by an embodiment of the utility model;

[0048] Fig.12 This is a circuit schematic diagram of a second DC power supply module provided in an embodiment of the utility model;

[0049] Fig.13 This is a partial circuit schematic diagram of an LED drive circuit provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0050] In order to enable people in the technical field to better understand the present solution, the technical solution in the embodiment of the present solution will be clearly described below in conjunction with the drawings in the embodiment of the present solution. Obviously, the described embodiment is an embodiment of a part of the present solution, not all of the embodiments. Based on the embodiments in the present solution, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present solution.

[0051] The term "including" and any other variations in the specification and claims of this solution and the above drawings mean "including but not limited to", and is intended to cover non-exclusive inclusions and is not limited to the examples listed in the text. In addition, the terms "first" and "second" are used to distinguish different objects, not to describe a specific order.

[0052] The following is a detailed description of the implementation of the present invention in conjunction with the specific drawings:

[0053] Figure 1The LED driving circuit is used to drive at least two LED light strings (LED1, ..., LEDn-1, LEDn) to emit light. Figure 1 The LED driving circuit includes: a constant current driving module 11, a current control module 12, a first number of switch tubes (Q1, ..., Qn-1), and a first number of sampling modules 13; wherein the first number is one less than the number of LED light strings;

[0054] For any switch tube, the switch tube, the sampling module 13 corresponding to the switch tube, and the LED light string corresponding to the switch tube are connected in series between the output end of the constant current driving module 11 and the first ground end;

[0055] The last LED light string (LEDn) is connected in series between the output end of the constant current driving module 11 and the first ground end;

[0056] The input end of the constant current driving module 11 is connected to a power source (eg, an AC power source), and the control end of the constant current driving module 11 is used to receive a dimming signal PWM;

[0057] The current control module 12 is connected to the output end of each sampling module 13 respectively, and receives the current (I1, ..., In-1) of each LED light string sampled by each sampling module 13;

[0058] The current control module 12 is further used to receive the color adjustment signal CCT and the dimming signal PWM, and send control signals (Sig1, ..., Sign-1) to each switch tube according to the dimming signal PWM, the color adjustment signal CCT and the sampled currents of each LED light string.

[0059] In the embodiment of the utility model, the constant current driving module 11 supplies power to each LED light string, and the total output current is a constant value. out =I1+I2+…+In-1+In, therefore, for n LED light strings, it is only necessary to sample and feedback the current of n-1 light strings to achieve accurate control of n LED light strings. The current control module 12 obtains the color modulation signal CCT, the dimming signal PWM and the current of each LED light string obtained by sampling. The dimming signal PWM can determine the total current I out, combined with the color adjustment signal CCT, the reference current of each LED light string can be determined, and the current of each (n-1) LED light string obtained by sampling is the actual current. The current of each (n-1) LED light string is compared with its corresponding reference current, and then the current of the LED light string is precisely controlled through the corresponding switch tube. If the current of n-1 LED light strings is accurate, the current of the nth LED light string must also be accurate, thereby achieving precise control of the current of all LED light strings, reducing the influence of the LED light source junction voltage on the color adjustment circuit, reducing the color tolerance of the product, and can also broaden more color adjustment circuit methods.

[0060] In a possible implementation, for any sampling module 13, the first end of the sampling module 13 is connected to the first ground end; the switch tube corresponding to the sampling module 13 and the LED light string corresponding to the sampling module 13 are connected in series between the second end of the sampling module 13 and the output end of the constant current driving module 11; the sampling module 13 may include: a first resistor R1;

[0061] A first end of the first resistor R1 is connected to a first end of the sampling module 13 , and a second end of the first resistor R1 is connected to a second end of the sampling module 13 and an output end of the sampling module 13 , respectively.

[0062] refer to Figure 2 In the embodiment of the utility model, a resistor is connected in series in each of the n-1 LED paths, and the current in the path is directly sampled through the resistor. The circuit is simple and effective.

[0063] In one possible implementation, reference Figure 3 , the above-mentioned LED driving circuit may further include: a color adjustment module 14;

[0064] The output terminal of the color adjustment module 14 is used to output a color adjustment signal CCT.

[0065] In one possible implementation, reference Figure 4 , the color adjustment module 14 may include: a gear selection unit 141, a second resistor R2 and a first capacitor C1;

[0066] The first end of the gear selection unit 141 is respectively connected to the first end of the second resistor R2, the first end of the first capacitor C1 and the output end of the color adjustment module 14, and the second end of the gear selection unit 141 is connected to the first ground end;

[0067] The second end of the second resistor R2 is connected to the first DC power supply VCC2; the second end of the first capacitor C1 is connected to the first ground terminal;

[0068] When in different gears, the resistance between the first end and the second end of the gear selection unit 141 is different.

[0069] In the embodiment of the utility model, the gear selection unit 141 is provided with a gear selection switch or a dial switch. When in different gears, the resistance of the gear selection switch is different. One end of the gear selection switch is grounded, and the second resistor R2 and the gear selection unit 141 are divided. When the gears are different, the resistance of the gear selection switch is different, and the voltage of the color adjustment signal CCT is different, so as to achieve color adjustment. The first capacitor C1 is used for filtering and stabilizing the voltage of the color adjustment signal CCT.

[0070] In one possible implementation, reference Figure 5 , the gear selection unit 141 may include: a multi-gear selection switch SS1 and a plurality of third resistors R3; wherein the resistance values ​​of the third resistors R3 are different;

[0071] The movable end of the multi-speed selection switch SS1 is connected to the second end of the gear selection unit 141, and each fixed end of the multi-speed selection switch SS1 is connected to the first end of the gear selection unit 141 through the corresponding third resistor R3.

[0072] refer to Figure 5 Each fixed end of the multi-speed selection switch SS1 is connected to the third resistor R3. When the movable end is connected to different fixed ends, switching of different resistance values ​​is achieved, thereby affecting the voltage of the color adjustment signal CCT. The circuit structure is simple, the number of components is small, and the cost is low.

[0073] In one possible implementation, reference Figure 3 , the LED driving circuit may further include: a dimming module 13;

[0074] The output end of the dimming module 13 is used to output a dimming signal PWM.

[0075] In one possible implementation, reference Figure 6 , the dimming signal is a PWM signal; the dimming module 13 may include: a dimming unit 131, a PWM generating unit 132 and an isolation unit 133;

[0076] The output end of the dimming unit 131 is connected to the input end of the PWM generating unit 132, and the output end of the PWM generating unit 132 is connected to the input end of the isolation unit 133;

[0077] The output terminal of the isolation unit 133 is used to output a dimming signal PWM.

[0078] The constant current driving module 11 adopts PWM dimming. In the embodiment of the utility model, the dimming unit 131 is used to generate an initial dimming signal; the PWM generation unit 132 is used to convert the initial dimming signal into a PWM signal; since the initial dimming signal is usually input by the user, in order to avoid introducing external interference, an isolation unit 133 is set to perform signal isolation to improve the safety of the circuit.

[0079] In one possible implementation, reference Figure 7 , the dimming unit 131 may include: a current source 1311, a dimming input subunit, a first voltage zener diode ZD1, a first diode D1, a second capacitor C2, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6;

[0080] The anode of the first zener diode ZD1 is connected to the second ground terminal, the cathode of the first zener diode ZD1 is connected to the output terminal of the current source 1311, the cathode of the first zener diode ZD1 is also connected to the first end of the fifth resistor R5, the first end of the second capacitor C2 and the output terminal of the dimming unit 131 through the fourth resistor R4, and the cathode of the first zener diode ZD1 is also connected to the anode of the first diode D1 through the sixth resistor R6;

[0081] A first end of the dimming input subunit is connected to the cathode of the first diode D1, and a second end of the dimming input subunit is connected to the second ground end;

[0082] The second end of the fifth resistor R5 and the second end of the second capacitor C2 are both connected to the second ground terminal;

[0083] When in different gears, the resistance of the dimming input sub-unit is different, so that the voltage at the output end of the dimming unit 131 is different.

[0084] In the embodiment of the utility model, the dimming input subunit is a passive resistive component, and the resistance of different gears is different. Therefore, the current source 1311 is set in the embodiment of the utility model to supply energy, and a path to the ground is formed through the sixth resistor R6, the first diode D1 and the dimming input subunit. When the resistance of the dimming input subunit is different, the voltage across the first voltage zener diode ZD1 is different, so that the voltage of the initial dimming signal is different; the fourth resistor R4 and the fifth resistor R5 are used for voltage division, and are adapted to the voltage of the PWM generation unit 132. The first voltage zener diode ZD1 is used for voltage stabilization to avoid overvoltage of the initial dimming signal and affect other components, thereby improving the safety of the circuit.

[0085] Specifically, the dimming unit 131 may further include a common mode inductor, see Figure 8 , which are arranged at both ends of the dimming input subunit for filtering, and the specific principle is not repeated here. It should be noted that other filtering elements can also be used, not limited to the above common mode inductors, as long as they can meet the filtering requirements.

[0086] For example, the circuit principle of the current source 1311 is shown in FIG. Figure 8 , the details will not be repeated here.

[0087] For example, the circuit schematic diagram of the PWM generation unit 132 is shown in FIG. Figure 8, I will not go into details here

[0088] Exemplarily, the isolation unit 133 can be implemented by an optical coupler. For a specific circuit schematic diagram, refer to Figure 8 It should be noted that the optocoupler input terminal is connected to the second ground terminal, and the optocoupler output terminal is connected to the first ground terminal to achieve ground isolation. The specific circuit principle will not be repeated here.

[0089] In one possible implementation, reference Fig. 9 , the power supply may be an AC power supply; the constant current driving module 11 may include: a rectifying unit 111 and a constant current driving unit 112;

[0090] The input end of the rectifier unit 111 is connected to the input end of the constant current drive module 11, and the output end of the rectifier unit 111 is connected to the input end of the constant current drive unit 112;

[0091] The control end of the constant current driving unit 112 is connected to the control end of the constant current driving module 11 , and the output end of the constant current driving unit 112 is connected to the output end of the constant current driving module 11 .

[0092] When the power source is an AC power source, a rectifying unit 111 is provided in the embodiment of the utility model for rectifying and outputting DC power.

[0093] For example, the circuit schematic diagram of the rectifier unit 11 is shown in FIG. Fig.10 The rectification is achieved by a rectifier bridge, and filtering is also designed to meet the electromagnetic compatibility requirements. The specific principle will not be repeated here.

[0094] For example, the circuit schematic diagram of the constant current driving unit 112 is shown in FIG. Fig.11 , the corresponding constant current I is output through the dimming signal control out , driving each LED string to emit light. The specific principle will not be described here.

[0095] For example, corresponding to Fig.11 The constant current driving unit 112 shown in FIG. Figure 8 In the embodiment of the utility model, a first DC power supply module is also provided, which takes power from the constant current driving unit 112 and provides low-voltage DC power to the PWM generating unit 132 and the current source 1311. Figure 8 , the details will not be repeated here.

[0096] For example, it also corresponds to Fig.11 The constant current driving unit 112 shown in FIG. Figure 4 In the embodiment of the utility model, a second DC power supply module is also provided. The specific schematic diagram of the second DC power supply module is shown in FIG. Fig.12, taking power from the output end of the constant current driving unit 112 , outputting direct current (first direct current power source VCC2 ) through a three-terminal regulator to supply power to the color adjustment module 14 .

[0097] Corresponding to the above LED driving circuit, the above LED driving circuit is described below in conjunction with a specific embodiment. Fig.13 The current control module 12 can be formed by a single chip microcomputer or other chips. The current control module 12 obtains the dimming signal PWM and the color modulation signal CCT, and determines the total output current I according to the dimming signal PWM. out , and then determine the reference current I of LED1 according to the color modulation signal CCT ref1 (The reference current of LED2 is I ref2 =I out -I ref1 ); at the same time, the current I1 flowing through LED1 is sampled through the first resistor R1; if I1>I ref1 Then, the current I1 flowing through LED1 is reduced by controlling Q1; the sampling is repeated until I1 = I ref1 Since the total current remains unchanged, if I1=I ref1 , then the current flowing through LED2 must be equal to the reference current of LED2, that is, I ref2 =I2. Similarly, if I1 ref1 , then by controlling Q1 to increase the current flowing through LED1, repeat sampling and judgment until I1 = I ref1 This enables precise control of the currents of the two LED light strings.

[0098] Corresponding to the above embodiments, the embodiments of the utility model further provide a lamp, comprising the LED driving circuit provided by any of the above embodiments, and having the advantages of the above LED driving circuit, which will not be described in detail here.

[0099] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.​

Claims

1. An LED driving circuit, characterized in that: Used to drive at least two LED light strings to emit light; The LED driving circuit comprises: a constant current driving module, a current control module, a first number of switch tubes, and a first number of sampling modules; wherein the first number is one less than the number of the LED light strings; For any switch tube, the switch tube, the sampling module corresponding to the switch tube, and the LED light string corresponding to the switch tube are connected in series between the output end of the constant current driving module and the first ground end; The last LED light string is connected in series between the output end of the constant current driving module and the first ground end; The input end of the constant current driving module is connected to the power supply, and the control end of the constant current driving module is used to receive a dimming signal; The current control module is connected to the output end of each sampling module respectively, and receives the current of each LED light string sampled by each sampling module; The current control module is further used to receive the color adjustment signal and the dimming signal, and send a control signal to each switch tube according to the dimming signal, the color adjustment signal and the sampled current of each LED light string.

2. The LED driving circuit according to claim 1, characterized in that: For any sampling module, the first end of the sampling module is connected to the first ground end; the switch tube corresponding to the sampling module and the LED light string corresponding to the sampling module are connected in series between the second end of the sampling module and the output end of the constant current driving module; the sampling module includes: a first resistor; The first end of the first resistor is connected to the first end of the sampling module, and the second end of the first resistor is connected to the second end of the sampling module and the output end of the sampling module respectively.

3. The LED driving circuit according to claim 1, characterized in that: Also includes: Color grading module; The output end of the color adjustment module is used to output the color adjustment signal.

4. The LED driving circuit according to claim 3, characterized in that: The color adjustment module includes: a gear selection unit, a second resistor and a first capacitor; The first end of the gear selection unit is respectively connected to the first end of the second resistor, the first end of the first capacitor and the output end of the color adjustment module, and the second end of the gear selection unit is connected to the first ground end; The second end of the second resistor is connected to the first DC power supply; the second end of the first capacitor is connected to the first ground terminal; Wherein, when in different gears, the resistance between the first end and the second end of the gear selection unit is different.

5. The LED driving circuit according to claim 4, characterized in that: The gear selection unit includes: a multi-gear selection switch and a plurality of third resistors; wherein the resistance values ​​of the third resistors are different; The movable end of the multi-speed selection switch is connected to the second end of the gear selection unit, and each fixed end of the multi-speed selection switch is connected to the first end of the gear selection unit through a corresponding third resistor.

6. The LED driving circuit according to any one of claims 1 to 5, characterized in that: Also includes: Dimming module; The output end of the dimming module is used to output the dimming signal.

7. The LED driving circuit according to claim 6, characterized in that: The dimming signal is a PWM signal; the dimming module includes: a dimming unit, a PWM generating unit and an isolation unit; The output end of the dimming unit is connected to the input end of the PWM generating unit, and the output end of the PWM generating unit is connected to the input end of the isolation unit; The output end of the isolation unit is used to output the dimming signal.

8. The LED driving circuit according to claim 7, characterized in that: The dimming unit includes: a current source, a dimming input subunit, a first voltage regulator diode, a first diode, a second capacitor, a fourth resistor, a fifth resistor and a sixth resistor; The anode of the first zener diode is connected to the second ground terminal, the cathode of the first zener diode is connected to the output terminal of the current source, the cathode of the first zener diode is also connected to the first end of the fifth resistor, the first end of the second capacitor and the output terminal of the dimming unit respectively through the fourth resistor, and the cathode of the first zener diode is also connected to the anode of the first diode through the sixth resistor; A first end of the dimming input subunit is connected to the cathode of the first diode, and a second end of the dimming input subunit is connected to the second ground end; The second end of the fifth resistor and the second end of the second capacitor are both connected to the second ground terminal; Wherein, when in different gears, the resistance of the dimming input subunit is different, so that the voltage at the output end of the dimming unit is different.

9. The LED driving circuit according to any one of claims 1 to 5, characterized in that: The power supply is an AC power supply; the constant current drive module includes: a rectifier unit and a constant current drive unit; The input end of the rectifier unit is connected to the input end of the constant current drive module, and the output end of the rectifier unit is connected to the input end of the constant current drive unit; The control end of the constant current driving unit is connected to the control end of the constant current driving module, and the output end of the constant current driving unit is connected to the output end of the constant current driving module.

10. A lamp, characterized in that: The LED driving circuit comprises the LED driving circuit as claimed in any one of claims 1 to 9.

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