A dimming control circuit and a lighting lamp

Abstract

The utility model provides a kind of dimming control circuit, including power access end, drive module, feedback module, adjustment module and voltage follower module, drive module is configured to the voltage size of the voltage size of output according to its feedback end received;Feedback module is connected in the loop where lighting module is, and its feedback output end is connected with feedback end, feedback module is configured to the corresponding feedback voltage signal and output according to the current size that it flows through is converted;Adjustment module is configured to be able to adjust the adjustment voltage signal of output;Voltage follower module includes voltage follower, the follower input end of voltage follower is connected with the adjustment output end of adjustment module, and the output end of voltage follower is connected with feedback module.The utility model's dimming control circuit can avoid load effect to influence adjustment module, so that dimming linearity is high, and cost is low.The utility model further provides a kind of lighting lamp.

Description

Technical Field

[0001] This utility model relates to the field of lighting equipment, and in particular to dimming control circuits and lighting fixtures. Background Technology

[0002] Currently, LED dimming technology is mainly divided into two categories: PWM dimming and analog dimming. While PWM dimming boasts excellent linearity (dimmer linearity can reach over 99%), it requires complex signal generation circuitry, increasing system costs by 30-50%. Traditional potentiometer-based analog dimming solutions, although structurally simple, suffer from significant nonlinearity (linearity typically below 85%) due to the direct coupling of the potentiometer impedance to the LED driver circuit, particularly exhibiting noticeable brightness jumps in low-brightness areas. Some existing patents using directly series potentiometers show dimming curve deviations as high as ±15% in the 10-30% brightness range. Furthermore, traditional solutions suffer from poor temperature stability and a narrow dimming range (typically not exceeding 20:1). These issues severely restrict the application of potentiometer dimming technology in high-end lighting scenarios. Utility Model Content

[0003] To overcome the shortcomings of existing technologies, this invention provides a dimming control circuit that isolates the adjustment module through a voltage follower module, preventing load effects from affecting the adjustment module. This results in high dimming accuracy (±2%) and low cost. This invention also provides a lighting fixture.

[0004] To achieve the above objectives, the present invention employs the following technical solution: A dimming control circuit for driving a lighting module, comprising: The power input terminal is used to connect to an external power source; A drive module has a drive output terminal and a feedback terminal. The drive module is connected to an external power source through the power input terminal to obtain electrical energy, processes the electrical energy, and supplies power to the lighting module through the drive output terminal. The drive module is configured to control the voltage output of its drive output terminal according to the voltage received at its feedback terminal. A feedback module has a feedback output terminal, which is connected to the feedback terminal of the drive module. The feedback module is connected in series in the circuit where the lighting module is located, and the feedback module is configured to convert the current flowing through it into a corresponding feedback voltage signal and output it through the feedback output terminal. An adjustment module having an adjustment output terminal, and the adjustment module being configured to adjust the magnitude of the adjustment voltage signal output by the adjustment output terminal; The voltage follower module includes a voltage follower having a follower input and a follower output. The follower input of the voltage follower is connected to the regulation output of the regulation module, and the follower output of the voltage follower is connected to the feedback module to apply the voltage output from the follower output to the feedback module.

[0005] Using the above technical solution, the user can operate the adjustment module to change the magnitude of its output adjustment voltage signal. The output of the voltage follower follows the change of the adjustment voltage signal. That is, the voltage applied to the feedback module by the voltage follower changes, so the magnitude of the current flowing through the feedback module changes, causing the output of its feedback output terminal to change. The output of the drive module changes accordingly, thereby realizing the dimming of the lighting module. Specifically, as the adjustment voltage signal output by the adjustment module increases, the output of the voltage follower also increases, meaning the voltage applied to the feedback module by the voltage follower increases. Consequently, the current flowing through the feedback module increases, raising the voltage at the feedback terminal of the drive module. This causes the output voltage of the drive module to decrease, resulting in lower brightness of the lighting module. As a result, the current flowing through the lighting module decreases, and this current also flows to the feedback module. Therefore, the total current flowing through the feedback module decreases and returns to a stable point, causing the voltage at the feedback terminal of the drive module to return to a stable point. The output voltage of the drive module then stabilizes again, completing the dimming process. The adjustment voltage signal output by the adjustment module decreases, and the output of the voltage follower also decreases, meaning the voltage applied to the feedback module by the voltage follower decreases. Consequently, the current flowing through the feedback module decreases, resulting in a lower voltage at the feedback terminal of the drive module. This causes the output voltage of the drive module to increase, leading to a higher brightness in the lighting module. This means the current flowing through the lighting module also increases, and this current will also flow to the feedback module. Therefore, the total current flowing through the feedback module increases and returns to a stable point, causing the voltage at the feedback terminal of the drive module to return to a stable point. The output voltage of the drive module then stabilizes again, completing the dimming process. In the above technical solution, the voltage follower has extremely high input impedance and extremely low output impedance, which isolates the adjustment module to a certain extent and avoids the load effect from affecting the adjustment module, thereby making the dimming control circuit have high dimming light sensitivity, which can reach ±2%.

[0006] Furthermore, the adjustment module includes a reference power supply and a voltage adjustment component. The reference power supply is used to provide a reference voltage. The voltage adjustment component has a high potential terminal, a low potential terminal and an adjustable output terminal. The high potential terminal is connected to the positive terminal of the reference power supply output of the reference power supply, the low potential terminal is connected to the negative terminal of the reference power supply output of the reference power supply, and the negative terminal of the reference power supply output of the reference power supply is connected to a reference ground. The adjustable output terminal is configured to output a corresponding voltage divider value according to its position relative to the high potential terminal and the low potential terminal, and the adjustable output terminal forms the regulating output terminal.

[0007] By adopting the above technical solution, the adjustment module becomes more rational, achieving adjustment of the output voltage signal based on the voltage divider principle. Specifically, the reference power supply provides a stable reference voltage output for the entire adjustment module, ensuring that the system has a reliable voltage reference. The high-potential terminal of the voltage adjustment component is directly connected to the positive terminal of the reference power supply, and the low-potential terminal of the voltage adjustment component is connected to the negative terminal of the reference power supply and forms a common ground connection with the reference ground, thereby establishing a complete voltage reference loop. The adjustable output terminal, by adjusting its relative position between the high and low potential terminals, outputs a corresponding proportional voltage divider value based on the resistor voltage divider law, realizing a continuously adjustable voltage output function. The above technical solution has high voltage adjustment accuracy and stable output.

[0008] Furthermore, the voltage regulation component employs a potentiometer, with its two ends forming a high-potential end and a low-potential end, respectively, and the tap of the potentiometer forming an adjustable output end.

[0009] By adopting the above technical solution, the voltage regulation component becomes more reasonable.

[0010] Furthermore, the reference power supply includes a voltage reference unit, which has a positive output terminal and a negative output terminal. The voltage reference unit is connected to the power supply input terminal to receive the supply voltage and outputs a reference voltage with a preset accuracy through the positive output terminal and the negative output terminal.

[0011] By adopting the above technical solution, the reference power supply is made more reasonable, enabling it to provide a high-precision voltage reference, thereby ensuring the adjustment accuracy and output stability of the adjustment module.

[0012] Furthermore, the voltage reference unit employs a three-terminal adjustable precision parallel voltage regulator. The anode of the three-terminal adjustable precision parallel voltage regulator is connected to the reference ground, the cathode of the three-terminal adjustable precision parallel voltage regulator is connected to the power input terminal, the reference terminal of the three-terminal adjustable precision parallel voltage regulator is shorted to its cathode, the cathode of the three-terminal adjustable precision parallel voltage regulator forms the positive output terminal of the reference power supply, and the anode of the three-terminal adjustable precision parallel voltage regulator forms the negative output terminal of the reference power supply.

[0013] By adopting the above technical solution, the voltage reference unit becomes more reasonable. Specifically, the voltage reference unit adopts the TL431A programmable precision voltage reference device; more specifically, the voltage reference unit constitutes a 2.5V precision reference source.

[0014] Furthermore, the reference power supply includes a seventh resistor, and the power supply input terminal is connected to the voltage reference unit through the seventh resistor.

[0015] By adopting the above technical solution, the reference power supply becomes more reasonable.

[0016] Furthermore, the reference power supply includes a seventh capacitor, one end of which is connected to the connection point between the power supply input terminal and the voltage reference unit, and the other end of which is connected to the reference ground.

[0017] By adopting the above technical solution, the reference unit becomes more reasonable; the setting of the seventh capacitor can filter the electrical energy output from the power input terminal to the voltage reference unit, ensuring the accuracy and stability of the reference power output.

[0018] Furthermore, the reference power supply includes an eighth capacitor, one end of which is connected to the positive output terminal of the reference power supply, and the other end of which is connected to reference ground.

[0019] By adopting the above technical solution, the reference unit becomes more reasonable; the setting of the eighth capacitor can filter the electrical energy supplied by the reference power supply to the voltage regulation component, ensuring the accuracy and stability of the output of the regulation module.

[0020] Furthermore, the drive module is used to boost electrical energy and then supply power to the lighting module through the drive output terminal.

[0021] The above technical solution makes the driving module more reasonable.

[0022] Furthermore, the driving module includes a boost unit, an energy storage inductor, and a first diode. The power input terminal is connected to the power input terminal of the boost unit and the first terminal of the energy storage inductor. The second terminal of the energy storage inductor is connected to the anode of the first diode. The cathode of the first diode is connected to the driving output terminal. The boost unit has the feedback terminal. The boost unit is configured to control whether the second terminal of the energy storage inductor is connected to the reference ground in a pulse width modulation manner, and to control the charging and discharging process of the energy storage inductor by adjusting the duty cycle through the feedback voltage signal received by its feedback terminal.

[0023] By adopting the above technical solution, the driving module becomes more reasonable. When the boost unit controls the second terminal of the energy storage inductor to connect to the reference ground, the energy storage inductor stores energy. When the boost unit controls the second terminal of the energy storage inductor to disconnect from the reference ground, the energy storage inductor releases electrical energy to the outside through the first diode. At this time, the voltage output by the driving module is the electrical voltage obtained from the external power supply at the power input terminal, i.e., the output voltage of the external power supply plus the induced electromotive force of the energy storage inductor, thereby realizing the boost operation. Since the boost unit controls whether the second terminal of the energy storage inductor is connected to the reference ground in a pulse width modulation manner, it can control the charging and discharging process of the energy storage inductor by changing the duty cycle, thereby realizing the voltage output by the drive module.

[0024] Furthermore, the boost unit has a first boost switch terminal and a second boost switch terminal; The first boost switch terminal is connected to the second terminal of the energy storage inductor, and the second boost switch terminal is connected to reference ground. Furthermore, the boost unit is configured to control the switching between the first boost switch terminal and the second boost switch terminal in a pulse width modulation manner.

[0025] By adopting the above technical solution, the boost unit becomes more reasonable. When the boost unit controls the first boost switch terminal and the second boost switch terminal to be turned on, the second terminal of the energy storage switch is connected to the reference ground. When the boost unit controls the second boost switch terminal and the second boost switch terminal to be turned off, the second terminal of the energy storage switch is disconnected from the reference ground.

[0026] Furthermore, the driving module includes a current-limiting resistor, the boost unit has a current sampling terminal, one end of the current-limiting resistor is connected to a reference ground, and the other end is connected to the current sampling terminal; and the driving module is configured to control and adjust the duty cycle according to the voltage magnitude collected by its current sampling terminal to limit the output power of the driving module.

[0027] By adopting the above technical solution, the driving module becomes more reasonable. The current-limiting resistor, in conjunction with the current sampling terminal, can limit the output power of the driving module, thereby limiting the input current of the driving module, realizing overcurrent protection, and ensuring the safe operating current of the internal components of the device.

[0028] Furthermore, the drive module includes a turn-off time setting capacitor, the boost unit has a turn-off time setting terminal, the turn-off time setting terminal is connected to one end of the turn-off time setting capacitor, and the other end of the turn-off time setting capacitor is connected to a reference ground.

[0029] By adopting the above technical solution, the driving module becomes more reasonable. The turn-off time of the boost unit is set by the turn-off time setting capacitor, thereby setting its operating frequency.

[0030] Furthermore, the driving module includes a frequency compensation capacitor, the boost unit has a frequency compensation terminal, the frequency compensation terminal is connected to one end of the frequency compensation capacitor, and the other end of the frequency compensation capacitor is connected to a reference ground.

[0031] By adopting the above technical solution, the driving module becomes more reasonable and is used for frequency compensation.

[0032] Furthermore, the boost unit has an enable terminal, which is connected to the power input terminal; The boost unit has a ground terminal, which is connected to a reference ground.

[0033] By adopting the above technical solution, the boost unit becomes more efficient. Furthermore, the boost unit employs a boost-type constant current driver. Specifically, the boost-type constant current driver uses an SL8530B chip. Pin 1 of the SL8530B chip is configured as the ground terminal, pin 2 as the enable terminal, pin 3 as the frequency compensation terminal, pin 4 as the feedback terminal, pin 5 as the first boost switch terminal, pin 6 as the second boost switch terminal and the current sampling terminal, pin 7 as the turn-off time setting terminal, and pin 8 as the power input terminal.

[0034] The above technical solution makes the boost unit more reasonable.

[0035] Furthermore, the voltage follower employs an operational amplifier, which has a non-inverting input terminal, an inverting input terminal, and an operational amplifier output terminal. The inverting input terminal is connected to the operational amplifier output terminal, the non-inverting input terminal forms the follower input terminal, and the operational amplifier output terminal forms the follower output terminal.

[0036] The above technical solution makes the voltage follower more reasonable.

[0037] Furthermore, the operational amplifier output terminal of the operational amplifier is output to the outside through the fifth resistor.

[0038] The above technical solution makes the voltage follower more reasonable.

[0039] Furthermore, the positive terminal of the operational amplifier is connected to the power input terminal through a sixth resistor, and the negative terminal of the operational amplifier is connected to the reference ground.

[0040] By adopting the above technical solution, the configuration of the operational amplifier becomes more reasonable.

[0041] Furthermore, the voltage follower module also includes a protection diode for providing input voltage clamping protection, the cathode of which is connected to the positive terminal of the operational amplifier power supply, and the positive terminal of which is connected to a reference ground.

[0042] By adopting the above technical solution, the voltage follower module becomes more reasonable, and the setting of the protection diode can clamp the voltage input to the operational amplifier, preventing the voltage input to the operational amplifier from exceeding its maximum withstand voltage, thus providing overvoltage protection for the operational amplifier.

[0043] Furthermore, the voltage follower module also includes a sixth capacitor for filtering, one end of which is connected to the positive power supply of the operational amplifier, and the other end of which is connected to the negative power supply of the operational amplifier.

[0044] By adopting the above technical solution, the voltage follower module becomes more reasonable, the sixth capacitor can filter out noise, and the operational amplifier can operate stably and reliably.

[0045] Furthermore, the protection diode is a Zener diode.

[0046] The above technical solution makes the protection diode more reasonable.

[0047] Furthermore, the operational amplifier uses the LM358 chip.

[0048] The above technical solution makes the operational amplifier more reasonable.

[0049] Furthermore, the driving module has an internal reference voltage, and the driving module is configured to: decrease the voltage output of its driving output terminal when the feedback voltage signal received by the feedback terminal is higher than its internal reference voltage, and increase the voltage output of its driving output terminal when the feedback voltage signal received by the feedback terminal is lower than its internal reference voltage.

[0050] By adopting the above technical solution, the driving module becomes more reasonable; Specifically, when the voltage supplied to the feedback terminal is equal to the internal reference voltage of the drive module, the output voltage of the drive module is stable; When the adjustment voltage signal output by the adjustment module increases, the output of the voltage follower also increases, meaning the voltage applied to the feedback module by the voltage follower increases. Consequently, the current flowing through the feedback module increases, raising the voltage at the feedback terminal of the drive module. Since the voltage at the feedback terminal is higher than the internal reference voltage of the drive module, the output voltage of the drive module decreases, and the brightness of the lighting module decreases. This means the current flowing through the lighting module decreases, and this current also flows to the feedback module. Therefore, the total current flowing through the feedback module decreases, causing the voltage at the feedback terminal of the drive module to decrease as well. This continues until the voltage at the feedback terminal is equal to the internal reference voltage of the drive module again, at which point the output voltage of the drive module stabilizes again, completing the dimming process. When the adjustment voltage signal output by the adjustment module decreases, the output of the voltage follower also decreases, meaning the voltage applied to the feedback module by the voltage follower decreases. Consequently, the current flowing through the feedback module decreases, causing the voltage fed back to the feedback terminal of the drive module to drop. Since the voltage at the feedback terminal is lower than the internal reference voltage of the drive module, the output voltage of the drive module increases, and the brightness of the lighting module increases. This means the current flowing through the lighting module also increases, and this current will also flow to the feedback module. Therefore, the total current flowing through the feedback module increases accordingly, causing the voltage fed back to the feedback terminal of the drive module to increase as well, until the voltage fed back to the feedback terminal is once again equal to the internal reference voltage of the drive module. At this point, the output voltage of the drive module stabilizes again, completing the dimming process.

[0051] Furthermore, the drive module includes a protection unit connected to the drive output terminal and the feedback terminal, and the protection unit is configured to: compare the voltage output by the drive output terminal with its internal voltage threshold, and pull the voltage of the feedback terminal to be greater than the internal reference voltage of the drive module when the voltage output by the drive output terminal is greater than its internal voltage threshold; and not output to the feedback terminal when the voltage output by the drive output terminal is less than its internal voltage threshold.

[0052] By adopting the above technical solution, the drive module becomes more reasonable and effectively realizes overvoltage protection for the load, that is, overvoltage protection for the lighting module. Specifically, when the voltage output by the drive output terminal is less than the voltage threshold inside the protection unit, the protection unit does not output to the feedback terminal. Therefore, the feedback terminal of the drive module receives the signal sent by the feedback module and controls and adjusts the output voltage according to the signal sent by the feedback module. When the voltage output from the drive output terminal is greater than the voltage threshold inside the protection unit, the protection unit outputs to the feedback terminal, and the output voltage is greater than the internal reference voltage of the drive module. At this time, since the voltage at the feedback terminal of the drive module is greater than the internal reference voltage of the drive module, the drive module will reduce its output voltage to achieve overvoltage protection for the load.

[0053] Furthermore, the protection unit includes a first Zener diode, the anode of which is connected to the feedback terminal, and the cathode of which is connected to the drive output terminal.

[0054] Using the above technical solution, when the voltage output by the drive output terminal is less than the voltage threshold inside the protection unit, that is, when the voltage output by the drive output terminal is less than the breakdown voltage of the first Zener diode, the first Zener diode is turned off, so that the voltage output by the drive output terminal cannot be output to the feedback terminal through the first Zener diode, that is, the protection unit does not output to the feedback terminal. When the voltage output from the drive output terminal is greater than the voltage threshold inside the protection unit, that is, when the voltage output from the drive output terminal is greater than the breakdown voltage of the first Zener diode, the first Zener diode breaks down and conducts, so that the voltage output from the drive output terminal is output to the feedback terminal through the first Zener diode. Generally, the voltage output from the drive output terminal is greater than the internal reference voltage of the drive module, that is, the protection unit pulls the voltage of the feedback terminal to be greater than the internal reference voltage of the drive module. Specifically, the voltage threshold of the protection unit is approximately 1.3 times the operating voltage of the lighting module, that is, the breakdown voltage of the first Zener diode is approximately 1.3 times the operating voltage of the lighting module.

[0055] Furthermore, the drive module includes a short-circuit protection unit for short-circuit protection, the short-circuit protection unit including a second diode, the anode of the second diode being connected to the cathode of the lighting module, and the cathode of the second diode being connected to a reference ground.

[0056] The above technical solution makes the driving module more reasonable.

[0057] Furthermore, the feedback module includes a feedback resistor, one end of which is connected to the negative terminal of the lighting module, and the other end of which is connected to a reference ground. The connection point between the feedback resistor and the negative terminal of the lighting module forms the feedback output terminal.

[0058] The above technical solution makes the feedback module more reasonable.

[0059] Furthermore, the driving module includes a fourth resistor and a fifth capacitor. One end of the fifth capacitor is connected to the feedback terminal, and the other end of the fifth capacitor is connected to the reference ground. The feedback output terminal of the feedback module is connected to the feedback terminal through the fourth resistor.

[0060] By adopting the above technical solution, the driving module becomes more reasonable. The fourth resistor serves to limit current and match impedance, while the fifth capacitor filters out high-frequency noise and stabilizes the voltage of the feedback signal, ensuring the purity and stability of the feedback signal.

[0061] Furthermore, the follower output terminal of the voltage follower is connected to one end of the fourth resistor that is used to connect to the feedback terminal.

[0062] The above technical solution makes the voltage follower module more reasonable.

[0063] Furthermore, the driving module includes a first resistor and a second capacitor. The power input terminal is connected to the power input terminal through the first resistor. The enable terminal of the boost unit is connected to the power input terminal through the first resistor. One end of the first resistor connected to the power input terminal and the enable terminal is connected to one end of the second capacitor. The other end of the second capacitor is connected to a reference ground. The driving module includes a second resistor, and the enable terminal is connected to the first resistor through the second resistor.

[0064] Using the above technical solution, the first resistor serves to limit current, and the second capacitor filters out high-frequency noise and stabilizes the voltage input to the power input terminal and the enable terminal, ensuring the purity and stability of the input voltage. The second resistor serves to limit the current.

[0065] Furthermore, the driving module includes an output filter capacitor, one end of which is connected to the driving output terminal, and the other end of which is connected to a reference ground. Specifically, the output filter capacitor is an electrolytic capacitor.

[0066] By adopting the above technical solution, the setting of the output filter capacitor can filter the output, ensuring that the lighting module works stably and reliably, and can maintain the stability of the output voltage.

[0067] Furthermore, the driving module includes a first input filter capacitor and / or a second input filter capacitor, one end of the first input filter capacitor is connected to the power input terminal, and the other end of the first input filter capacitor is connected to a reference ground; one end of the second input filter capacitor is connected to the power input terminal, and the other end of the second input filter capacitor is connected to a reference ground. Specifically, the driving module includes a first input filter capacitor and a second input filter capacitor; the first input filter capacitor is an electrolytic capacitor, and the second input filter capacitor is a regular capacitor.

[0068] By adopting the above technical solution, the setting of the first input filter capacitor and / or the second input filter capacitor can perform a filtering operation on the input, remove noise, and ensure the stable and reliable operation of subsequent devices.

[0069] Furthermore, the driving module includes a third resistor, one end of which is connected to the driving output terminal, and the other end of which is connected to a reference ground.

[0070] By adopting the above technical solution, the driving module becomes more reasonable. The third resistor acts as a dummy load. When the driving module is under light load or no load, the circuit may experience unstable output voltage and large fluctuations. The third resistor, as a dummy load, can provide a stable reference load, which helps to maintain the stability of the output voltage.

[0071] A lighting fixture includes the dimming control circuit described above and a lighting module for emitting light, wherein the positive terminal of the lighting module is connected to the drive output terminal and the negative terminal of the lighting module is connected to a reference ground.

[0072] The above technical solution makes the lighting fixture more reasonable; it greatly improves the dimming accuracy of the lighting module, which can reach ±2%, and is low in cost. It also improves the light jitter in the traditional potentiometer dimming process and has a wide dimming range.

[0073] Compared with the prior art, the present invention has the following beneficial effects: (1) The dimming control circuit and lighting fixture of this utility model isolate the adjustment module through the voltage follower module to avoid the load effect affecting the adjustment module, thereby making the dimming control circuit have high dimming light sensitivity, up to ±2%, and low cost.

[0074] (2) The dimming control circuit and lighting fixture of this utility model have a reasonable structural design. Attached Figure Description

[0075] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0076] Figure 1 This is a schematic diagram of the circuit structure of the drive module and the feedback module in the dimming control circuit of this utility model; Figure 2 This is a schematic diagram of the circuit structure of the voltage follower module in the dimming control circuit of this utility model; Figure 3 This is a schematic diagram of the circuit structure of the adjustment module in the dimming control circuit of this utility model; Figure 4 The formula for calculating the output current of the dimming control circuit of this utility model is as follows; Figure 5 This is a schematic diagram showing the relationship between the output current ILED and the potentiometer's resistance to ground Rx in the dimming control circuit of this utility model. The component names corresponding to the various reference numerals in the figure are as follows: 1. Power input terminal; 2. Drive module; 201. Drive output terminal; 202. Protection unit; 203. Short circuit protection unit; 3. Feedback module; 301. Feedback output terminal; 4. Adjustment module; 401. Adjustment output terminal; 402. Reference power supply; 4021. Positive output terminal of reference power supply; 4022. Negative output terminal of reference power supply; 4023. Voltage reference unit; 403. Voltage adjustment component; 4031. High potential terminal; 4032. Low potential terminal; 4033. Adjustable output terminal; 5. Voltage follower module; 501. Voltage follower; 5011. Follower input terminal; 5012. Follower output terminal; U1, Boost Unit; FB, Feedback Terminal; VDD, Power Input Terminal; DRV, First Boost Switch Terminal; SE, Second Boost Switch Terminal; CS, Current Sampling Terminal; Toff, Turn-off Time Setting Terminal; COMP, Frequency Compensation Terminal; EN, Enable Terminal; G, Ground Terminal; L1, Energy Storage Inductor; L1-1, First Terminal; L1-2, Second Terminal; D1, First Diode; D2, Second Diode; ZD1, First Zener Diode; ZD2, Protection Diode; RS1, Current Limiting Resistor; RS2, Feedback Resistor; R1, First Resistor; R2, Second Resistor; R3, Third Resistor; R4, Fourth Resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; RP1, potentiometer; EC1, first input filter capacitor; EC2, output filter capacitor; C1, second input filter capacitor; C2, second capacitor; C3, off-time setting capacitor; C4, frequency compensation capacitor; C5, fifth capacitor; C6, sixth capacitor; C7, seventh capacitor; C8, eighth capacitor; U2, operational amplifier; U2-1, non-inverting input; U2-2, inverting input; U2-3, operational amplifier output; U3, three-terminal adjustable precision parallel voltage regulator; GND, reference ground; LED1, lighting module. Detailed Implementation

[0077] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0078] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0079] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0080] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0081] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0082] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0083] The technical solutions provided by the various embodiments of this application are described below with reference to the accompanying drawings.

[0084] See Figures 1 to 5 This utility model provides a dimming control circuit for driving a lighting module LED1, comprising: Power input terminal 1, which is used to connect to an external power source; The driving module 2 has a driving output terminal 201 and a feedback terminal FB. The driving module 2 is connected to an external power source through the power input terminal 1 to obtain electrical energy, processes the electrical energy, and supplies power to the lighting module LED1 through the driving output terminal 201. The driving module 2 is configured to control the voltage output of its driving output terminal 201 according to the voltage received by its feedback terminal FB. Feedback module 3 has a feedback output terminal 301, which is connected to the feedback terminal FB of the drive module 2. The feedback module 3 is connected in series in the circuit where the lighting module LED1 is located, and the feedback module 3 is configured to convert the current flowing through it into a corresponding feedback voltage signal and output it through the feedback output terminal 301. The adjustment module 4 has an adjustment output terminal 401, and the adjustment module 4 is configured to adjust the magnitude of the adjustment voltage signal output by the adjustment output terminal 401. And a voltage follower module 5, which includes a voltage follower 501, the voltage follower 501 having a follower input terminal 5011 and a follower output terminal 5012, the follower input terminal 5011 of the voltage follower 501 being connected to the adjustment output terminal 401 of the adjustment module 4, and the follower output terminal of the voltage follower 501 being connected to the feedback module 3 to apply the voltage output by the follower output terminal to the feedback module 3.

[0085] Using the above technical solution, the user can operate the adjustment module 4 to change the magnitude of its output adjustment voltage signal. The output of the voltage follower 501 follows the change of the adjustment voltage signal. That is, the voltage applied to the feedback module 3 by the voltage follower 501 changes, so the magnitude of the current flowing through the feedback module 3 changes, causing the output of its feedback output terminal 301 to change. The output of the drive module 2 changes accordingly, thereby realizing the dimming of the lighting module LED1. Specifically, when the adjustment voltage signal output by the adjustment module 4 increases, the output of the voltage follower 501 also increases, meaning the voltage applied to the feedback module 3 by the voltage follower 501 increases. Consequently, the current flowing through the feedback module 3 increases, increasing the voltage fed back to the feedback terminal FB of the drive module 2. This causes the output voltage of the drive module 2 to decrease, resulting in a lower brightness for the lighting module LED1. As a result, the current flowing through the lighting module LED1 decreases, and this current also flows to the feedback module 3. Therefore, the total current flowing through the feedback module 3 decreases and returns to a stable point, causing the voltage fed back to the feedback terminal FB of the drive module 2 to return to a stable point. The output voltage of the drive module 2 then stabilizes again, completing the dimming process. The adjustment voltage signal output by the adjustment module 4 decreases, and the output of the voltage follower 501 also decreases, meaning the voltage applied to the feedback module 3 by the voltage follower 501 decreases. Consequently, the current flowing through the feedback module 3 decreases, causing the voltage fed back to the feedback terminal FB of the drive module 2 to decrease. This results in the voltage output by the drive module 2 increasing, and the brightness of the lighting module LED1 increasing. This means the current flowing through the lighting module LED1 also increases, and this current will also flow to the feedback module 3. Therefore, the total current flowing through the feedback module 3 increases accordingly and returns to a stable point, causing the voltage fed back to the feedback terminal FB of the drive module 2 to return to a stable point. The voltage output by the drive module 2 then stabilizes again, completing the dimming process. In the above technical solution, the voltage follower 501 has extremely high input impedance and extremely low output impedance, which isolates the adjustment module 4 to a certain extent and avoids the load effect from affecting the adjustment module 4, thereby making the dimming control circuit have high dimming light sensitivity, which can reach ±2%.

[0086] Furthermore, the adjustment module 4 includes a reference power supply 402 and a voltage adjustment component 403. The reference power supply 402 is used to provide a reference voltage. The voltage adjustment component 403 has a high potential terminal 4031, a low potential terminal 4032 and an adjustable output terminal 4033. The high potential terminal 4031 is connected to the reference power supply output positive terminal 4021 of the reference power supply 402. The low potential terminal 4032 is connected to the reference power supply output negative terminal 4022 of the reference power supply 402. The reference power supply output negative terminal 4022 of the reference power supply 402 is connected to the reference ground GND. The adjustable output terminal 4033 is configured to output a corresponding voltage divider value according to its position relative to the high potential terminal 4031 and the low potential terminal 4032, and the adjustable output terminal 4033 forms the adjustable output terminal 401.

[0087] By adopting the above technical solution, the adjustment module 4 becomes more reasonable, and the adjustment of the output voltage signal is realized based on the voltage divider principle. Specifically, the reference power supply 402 provides a stable reference voltage output for the entire adjustment module 4, ensuring that the system has a reliable voltage reference. The high potential terminal 4031 of the voltage adjustment component 403 is directly connected to the positive terminal of the reference power supply 402, and the low potential terminal 4032 of the voltage adjustment component 403 is connected to the negative terminal of the reference power supply 402 and forms a common ground connection with the reference ground GND, thereby establishing a complete voltage reference circuit. The adjustable output terminal 4033, by adjusting its relative position between the high and low potential terminals 4032, outputs a corresponding proportional voltage divider value based on the voltage divider law, realizing a continuously adjustable voltage output function. The above technical solution has high voltage adjustment accuracy and stable output.

[0088] Furthermore, the voltage regulation component 403 adopts a potentiometer RP1, the two ends of the potentiometer RP1 are respectively formed as the high potential end 4031 and the low potential end 4032, and the tap of the potentiometer RP1 is formed as the adjustable output end 4033.

[0089] By adopting the above technical solution, the voltage regulation component 403 becomes more reasonable.

[0090] Furthermore, the reference power supply 402 includes a voltage reference unit 4023, which has a reference power supply output positive terminal 4021 and a reference power supply output negative terminal 4022. The voltage reference unit 4023 is connected to the power input terminal 1 to receive the supply voltage and outputs a reference voltage with a preset accuracy through the reference power supply output positive terminal 4021 and the reference power supply output negative terminal 4022.

[0091] By adopting the above technical solution, the reference power supply 402 is made more reasonable, enabling it to provide a high-precision voltage reference, thereby ensuring the adjustment accuracy and output stability of the adjustment module 4.

[0092] Furthermore, the voltage reference unit 4023 adopts a three-terminal adjustable precision parallel voltage regulator U3. The anode of the three-terminal adjustable precision parallel voltage regulator U3 is connected to the reference ground GND, the cathode of the three-terminal adjustable precision parallel voltage regulator U3 is connected to the power input terminal 1, the reference terminal of the three-terminal adjustable precision parallel voltage regulator U3 is shorted to its cathode, the cathode of the three-terminal adjustable precision parallel voltage regulator U3 is formed as the positive terminal 4021 of the reference power supply output, and the anode of the three-terminal adjustable precision parallel voltage regulator U3 is formed as the negative terminal 4022 of the reference power supply output.

[0093] By adopting the above technical solution, the voltage reference unit 4023 becomes more reasonable. Specifically, the voltage reference unit 4023 adopts the TL431A programmable precision voltage reference device; more specifically, the voltage reference unit 4023 constitutes a 2.5V precision reference source.

[0094] Furthermore, the reference power supply 402 includes a seventh resistor R7, and the power input terminal 1 is connected to the voltage reference unit 4023 through the seventh resistor R7.

[0095] By adopting the above technical solution, the reference power supply 402 becomes more reasonable.

[0096] Furthermore, the reference power supply 402 includes a seventh capacitor C7, one end of which is connected to the connection point between the power input terminal 1 and the voltage reference unit 4023, and the other end of which is connected to the reference ground GND.

[0097] By adopting the above technical solution, the reference unit becomes more reasonable; the setting of the seventh capacitor C7 can filter the electrical energy output from the power input terminal 1 to the voltage reference unit 4023, ensuring the accuracy and stability of the output of the reference power supply 402.

[0098] Furthermore, the reference power supply 402 includes an eighth capacitor C8, one end of which is connected to the positive output terminal 4021 of the reference power supply, and the other end of which is connected to the reference ground GND.

[0099] By adopting the above technical solution, the reference unit becomes more reasonable; the setting of the eighth capacitor C8 can filter the electrical energy output from the reference power supply 402 to the voltage regulation component 403, ensuring the accuracy and stability of the output of the regulation module 4.

[0100] Furthermore, the drive module 2 is used to boost the electrical energy and then supply power to the lighting module LED1 through the drive output terminal 201.

[0101] The above technical solution makes the driving module 2 more reasonable.

[0102] Furthermore, the driving module 2 includes a boost unit U1, an energy storage inductor L1, and a first diode D1. The power input terminal 1 is connected to the power input terminal VDD of the boost unit U1 and the first terminal L1-1 of the energy storage inductor L1. The second terminal L1-2 of the energy storage inductor L1 is connected to the anode of the first diode D1. The cathode of the first diode D1 is connected to the driving output terminal 201. The boost unit U1 has the feedback terminal FB. The boost unit U1 is configured to control whether the second terminal L1-2 of the energy storage inductor L1 is connected to the reference ground GND in a pulse width modulation manner, and to control the charging and discharging process of the energy storage inductor L1 by adjusting the duty cycle through the feedback voltage signal received by its feedback terminal FB.

[0103] By adopting the above technical solution, the driving module 2 becomes more reasonable. When the boost unit U1 controls the second terminal L1-2 of the energy storage inductor L1 to connect to the reference ground GND, the energy storage inductor L1 stores energy. When the boost unit U1 controls the second terminal L1-2 of the energy storage inductor L1 to disconnect from the reference ground GND, the energy storage inductor L1 releases electrical energy to the outside through the first diode D1. At this time, the voltage output by the driving module 2 is the electrical voltage obtained by the power input terminal 1 from the external power supply, that is, the output voltage of the external power supply plus the induced electromotive force of the energy storage inductor L1, thereby realizing the boost operation. Since the boost unit U1 controls whether the second terminal L1-2 of the energy storage inductor L1 is connected to the reference ground GND by pulse width modulation, it can control the charging and discharging process of the energy storage inductor L1 by changing the duty cycle, thereby realizing the voltage output by the drive module 2.

[0104] Furthermore, the boost unit U1 has a first boost switch terminal DRV and a second boost switch terminal SE; The first boost switch terminal DRV is connected to the second terminal L1-2 of the energy storage inductor L1, and the second boost switch terminal SE is connected to the reference ground GND. Furthermore, the boost unit U1 is configured to control the switching between the first boost switch terminal DRV and the second boost switch terminal SE in a pulse width modulation manner.

[0105] By adopting the above technical solution, the boost unit U1 is made more reasonable. When the boost unit U1 controls the first boost switch terminal DRV and the second boost switch terminal SE to be turned on, the second terminal L1-2 of the energy storage switch is connected to the reference ground GND. When the boost unit U1 controls the second boost switch terminal SE to be turned off, the second terminal L1-2 of the energy storage switch is disconnected from the reference ground GND.

[0106] Furthermore, the driving module 2 includes a current-limiting resistor RS1, the boost unit U1 has a current sampling terminal CS, one end of the current-limiting resistor RS1 is connected to the reference ground GND, and the other end is connected to the current sampling terminal CS; and the driving module 2 is configured to control and adjust the duty cycle according to the voltage magnitude collected by its current sampling terminal CS, so as to limit the output power of the driving module 2.

[0107] By adopting the above technical solution, the driving module 2 becomes more reasonable. The current limiting resistor RS1, together with the current sampling terminal CS, can limit the output power of the driving module 2, thereby limiting the input current of the driving module 2, realizing overcurrent protection, and ensuring the safe operating current of the internal components of the device.

[0108] Furthermore, the drive module 2 includes a turn-off time setting capacitor C3, the boost unit U1 has a turn-off time setting terminal Toff, the turn-off time setting terminal Toff is connected to one end of the turn-off time setting capacitor C3, and the other end of the turn-off time setting capacitor C3 is connected to the reference ground GND.

[0109] By adopting the above technical solution, the driving module 2 becomes more reasonable. The turn-off time of the boost unit U1 is set by the turn-off time setting capacitor C3, thereby setting its operating frequency.

[0110] Furthermore, the driving module 2 includes a frequency compensation capacitor C4, the boost unit U1 has a frequency compensation terminal COMP, the frequency compensation terminal COMP is connected to one end of the frequency compensation capacitor C4, and the other end of the frequency compensation capacitor C4 is connected to the reference ground GND.

[0111] By adopting the above technical solution, the driving module 2 becomes more reasonable and is used for frequency compensation.

[0112] Furthermore, the boost unit U1 has an enable terminal EN, which is connected to the power input terminal 1. The boost unit U1 has a ground terminal G, which is connected to the reference ground GND.

[0113] By adopting the above technical solution, the boost unit U1 becomes more reasonable. Furthermore, the boost unit U1 employs a boost-type constant current driver. Specifically, the boost-type constant current driver uses an SL8530B chip. Pin 1 of the SL8530B chip is configured as the ground terminal G, pin 2 as the enable terminal EN, pin 3 as the frequency compensation terminal COMP, pin 4 as the feedback terminal FB, pin 5 as the first boost switch terminal DRV, pin 6 as the second boost switch terminal SE and the current sampling terminal CS, pin 7 as the off-time setting terminal Toff, and pin 8 as the power input terminal VDD.

[0114] By adopting the above technical solution, the boost unit U1 becomes more reasonable.

[0115] Furthermore, the voltage follower 501 employs an operational amplifier U2, which has a non-inverting input terminal U2-1, an inverting input terminal U2-2, and an operational amplifier output terminal U2-3. The inverting input terminal U2-2 is connected to the operational amplifier output terminal U2-3. The non-inverting input terminal U2-1 is formed as the follower input terminal 5011, and the operational amplifier output terminal U2-3 is formed as the follower output terminal 5012.

[0116] The above technical solution makes the voltage follower 501 more reasonable.

[0117] Furthermore, the operational amplifier output terminal U2-3 of the operational amplifier U2 is output to the outside through the fifth resistor R5.

[0118] The above technical solution makes the voltage follower 501 more reasonable.

[0119] Furthermore, the positive power supply terminal of the operational amplifier U2 is connected to the power input terminal 1 through the sixth resistor R6, and the negative power supply terminal of the operational amplifier U2 is connected to the reference ground GND.

[0120] By adopting the above technical solution, the configuration of the operational amplifier U2 is made more reasonable.

[0121] Furthermore, the voltage follower module 5 also includes a protection diode ZD2 for providing input voltage clamping protection. The cathode of the protection diode ZD2 is connected to the positive terminal of the power supply of the operational amplifier U2, and the anode of the protection diode ZD2 is connected to the reference ground GND.

[0122] By adopting the above technical solution, the voltage follower module 5 is made more reasonable. The setting of the protection diode ZD2 can clamp the voltage input to the operational amplifier U2, so as to prevent the voltage input to the operational amplifier U2 from exceeding its maximum withstand voltage, thus providing overvoltage protection for the operational amplifier U2.

[0123] Furthermore, the voltage follower module 5 also includes a sixth capacitor C6 for filtering. One end of the sixth capacitor C6 is connected to the positive power supply of the operational amplifier U2, and the other end of the sixth capacitor C6 is connected to the negative power supply of the operational amplifier U2.

[0124] By adopting the above technical solution, the voltage follower module 5 becomes more reasonable, and the sixth capacitor C6 can filter out noise, ensuring the stable and reliable operation of the operational amplifier U2.

[0125] Furthermore, the protection diode ZD2 is a Zener diode.

[0126] The above technical solution makes the protection diode ZD2 more reasonable.

[0127] Furthermore, the operational amplifier U2 uses an LM358 chip.

[0128] The above technical solution makes the operational amplifier U2 more reasonable.

[0129] Furthermore, the driving module 2 has an internal reference voltage, and the driving module 2 is configured to: reduce the voltage output of its driving output terminal 201 when the feedback voltage signal received by the feedback terminal FB is higher than its internal reference voltage, and increase the voltage output of its driving output terminal 201 when the feedback voltage signal received by the feedback terminal FB is lower than its internal reference voltage.

[0130] By adopting the above technical solution, the driving module 2 becomes more reasonable; Specifically, when the voltage input to the feedback terminal FB is equal to the internal reference voltage of the drive module 2, the output voltage of the drive module 2 is stable; When the adjustment voltage signal output by the adjustment module 4 increases, the output of the voltage follower 501 also increases, meaning the voltage applied to the feedback module 3 by the voltage follower 501 increases. Consequently, the current flowing through the feedback module 3 increases, raising the voltage at the feedback terminal FB of the drive module 2. Since the voltage at the feedback terminal FB is higher than the internal reference voltage of the drive module 2, the output voltage of the drive module 2 decreases, and the brightness of the lighting module LED1 decreases. This means the current flowing through the lighting module LED1 decreases, and this current also flows to the feedback module 3. Therefore, the total current flowing through the feedback module 3 decreases, causing the voltage at the feedback terminal FB of the drive module 2 to decrease as well. This continues until the voltage at the feedback terminal FB is equal to the internal reference voltage of the drive module 2 again, at which point the output voltage of the drive module 2 stabilizes again, completing the dimming process. When the adjustment voltage signal output by the adjustment module 4 decreases, the output of the voltage follower 501 also decreases, meaning the voltage applied to the feedback module 3 by the voltage follower 501 decreases. Consequently, the current flowing through the feedback module 3 decreases, causing the voltage at the feedback terminal FB of the drive module 2 to drop. Since the voltage at the feedback terminal FB is lower than the internal reference voltage of the drive module 2, the output voltage of the drive module 2 increases, and the brightness of the lighting module LED1 increases. This means the current flowing through the lighting module LED1 also increases, and this current also flows to the feedback module 3. Therefore, the total current flowing through the feedback module 3 increases accordingly, causing the voltage at the feedback terminal FB of the drive module 2 to increase as well, until the voltage at the feedback terminal FB is equal to the internal reference voltage of the drive module 2 again. At this point, the output voltage of the drive module 2 stabilizes again, completing the dimming process.

[0131] Furthermore, the drive module 2 includes a protection unit 202, which is connected to the drive output terminal 201 and the feedback terminal FB. The protection unit 202 is configured to: compare the voltage output by the drive output terminal 201 with its internal voltage threshold, and pull the voltage of the feedback terminal FB to be greater than the internal reference voltage of the drive module 2 when the voltage output by the drive output terminal 201 is greater than its internal voltage threshold; and not output to the feedback terminal FB when the voltage output by the drive output terminal 201 is less than its internal voltage threshold.

[0132] By adopting the above technical solution, the driving module 2 becomes more reasonable and effectively realizes overvoltage protection for the load, that is, overvoltage protection for the lighting module LED1. Specifically, when the voltage output by the drive output terminal 201 is less than the voltage threshold inside the protection unit 202, the protection unit 202 does not output to the feedback terminal FB. Therefore, the feedback terminal FB of the drive module 2 receives the signal sent by the feedback module 3 and controls and adjusts the output voltage according to the signal sent by the feedback module 3. When the voltage output by the drive output terminal 201 is greater than the voltage threshold inside the protection unit 202, the protection unit 202 outputs to the feedback terminal FB, and the voltage output is greater than the internal reference voltage of the drive module 2. At this time, since the voltage of the feedback terminal FB of the drive module 2 is greater than the internal reference voltage of the drive module 2, the drive module 2 will reduce the voltage output to achieve overvoltage protection for the load.

[0133] Furthermore, the protection unit 202 includes a first Zener diode ZD1, the anode of the first Zener diode ZD1 is connected to the feedback terminal FB, and the cathode of the first Zener diode ZD1 is connected to the drive output terminal 201.

[0134] Using the above technical solution, when the voltage output by the drive output terminal 201 is less than the voltage threshold inside the protection unit 202, that is, when the voltage output by the drive output terminal 201 is less than the breakdown voltage of the first Zener diode ZD1, the first Zener diode is turned off, so that the voltage output by the drive output terminal 201 cannot be output to the feedback terminal FB through the first Zener diode, that is, the protection unit 202 does not output to the feedback terminal FB; When the voltage output by the drive output terminal 201 is greater than the voltage threshold inside the protection unit 202, that is, when the voltage output by the drive output terminal 201 is greater than the breakdown voltage of the first Zener diode ZD1, the first Zener diode breaks down and conducts, so that the voltage output by the drive output terminal 201 is output to the feedback terminal FB through the first Zener diode. Generally, the voltage output by the drive output terminal 201 is greater than the internal reference voltage of the drive module 2, that is, the protection unit 202 pulls the voltage of the feedback terminal FB to be greater than the internal reference voltage of the drive module 2. Specifically, the voltage threshold of the protection unit 202 is approximately 1.3 times the operating voltage of the lighting module LED1, that is, the breakdown voltage of the first Zener diode ZD1 is approximately 1.3 times the operating voltage of the lighting module LED1.

[0135] Furthermore, the driving module 2 includes a short-circuit protection unit 203 for short-circuit protection. The short-circuit protection unit 203 includes a second diode D2. The anode of the second diode D2 is connected to the cathode of the lighting module LED1, and the cathode of the second diode D2 is connected to the reference ground GND.

[0136] The above technical solution makes the driving module 2 more reasonable.

[0137] Furthermore, the feedback module 3 includes a feedback resistor RS2, one end of which is connected to the negative terminal of the lighting module LED1, and the other end of which is connected to the reference ground GND. The connection point between the feedback resistor RS2 and the negative terminal of the lighting module LED1 forms the feedback output terminal 301.

[0138] By adopting the above technical solution, the feedback module 3 becomes more reasonable.

[0139] Furthermore, the driving module 2 includes a fourth resistor R4 and a fifth capacitor C5. One end of the fifth capacitor C5 is connected to the feedback terminal FB, and the other end of the fifth capacitor C5 is connected to the reference ground GND. The feedback output terminal 301 of the feedback module 3 is connected to the feedback terminal FB through the fourth resistor R4.

[0140] By adopting the above technical solution, the driving module 2 becomes more reasonable. The fourth resistor R4 serves to limit current and match impedance, and the fifth capacitor C5 filters out high-frequency noise and stabilizes the voltage of the feedback terminal FB signal, ensuring the purity and stability of the feedback signal.

[0141] Furthermore, the voltage follower 501's follower output terminal is connected to one end of the fourth resistor R4 used for connection to the feedback terminal FB.

[0142] The above technical solution makes the voltage follower module 5 more reasonable.

[0143] Furthermore, the driving module 2 includes a first resistor R1 and a second capacitor C2. The power input terminal VDD is connected to the power input terminal 1 through the first resistor R1. The enable terminal EN of the boost unit U1 is connected to the power input terminal 1 through the first resistor R1. One end of the first resistor R1 connected to the power input terminal 1 and the enable terminal EN is connected to one end of the second capacitor C2. The other end of the second capacitor C2 is connected to the reference ground GND. The drive module 2 includes a second resistor R2, and the enable terminal EN is connected to the first resistor R1 through the second resistor R2.

[0144] Using the above technical solution, the first resistor R1 serves to limit the current, and the second capacitor C2 performs high-frequency noise filtering and voltage stabilization on the voltage input to the power input terminal 1 and the enable terminal EN, ensuring the purity and stability of the input voltage. The second resistor R2 serves to limit the current.

[0145] Furthermore, the driving module 2 includes an output filter capacitor EC2, one end of which is connected to the driving output terminal 201, and the other end of which is connected to the reference ground GND. Specifically, the output filter capacitor EC2 is an electrolytic capacitor.

[0146] By adopting the above technical solution, the setting of the output filter capacitor EC2 can filter the output, ensuring that the lighting module LED1 works stably and reliably, and can maintain the stability of the output voltage.

[0147] Furthermore, the driving module 2 includes a first input filter capacitor EC1 and / or a second input filter capacitor C1. One end of the first input filter capacitor EC1 is connected to the power input terminal 1, and the other end of the first input filter capacitor EC1 is connected to the reference ground GND. One end of the second input filter capacitor C1 is connected to the power input terminal 1, and the other end of the second input filter capacitor C1 is connected to the reference ground GND. Specifically, the driving module 2 includes a first input filter capacitor EC1 and a second input filter capacitor C1; the first input filter capacitor EC1 is an electrolytic capacitor, and the second input filter capacitor C1 is a regular capacitor.

[0148] By adopting the above technical solution, the setting of the first input filter capacitor EC1 and / or the second input filter capacitor C1 can perform input filtering operation, remove noise, and ensure the stable and reliable operation of subsequent devices.

[0149] Furthermore, the driving module 2 includes a third resistor R3, one end of which is connected to the driving output terminal 201, and the other end of which is connected to the reference ground GND.

[0150] By adopting the above technical solution, the driving module 2 becomes more reasonable. The third resistor R3 acts as a dummy load. When the driving module 2 is under light load or no load, the circuit may experience unstable output voltage and large fluctuations. The third resistor R3, as a dummy load, can provide a stable reference load, which helps to maintain the stability of the output voltage.

[0151] The output current of the dimming control circuit can be approximated by... Figure 4The formula shown indicates that, and Figure 4 In this diagram, VR is the voltage across the potentiometer tap to ground; VFB is the reference voltage of the boost unit, specifically 0.25V; Rx is the resistance of the potentiometer tap to ground; RS2 is the resistance of the feedback resistor; RP1 is the nominal maximum resistance of the potentiometer; R4 and R5 are the resistances of the fourth and fifth resistors, respectively; Vbase is the reference voltage output from the reference power supply, specifically 2.5V; if the value of ILED in the calculation is negative, it indicates that the output current is 0.

[0152] See Figure 5 The graph shows the relationship when the nominal maximum resistance of the potentiometer is 200KΩ.

[0153] See Figures 1 to 5 A lighting fixture includes the dimming control circuit described above and a lighting module LED1 for emitting light. The positive terminal of the lighting module LED1 is connected to the drive output terminal 201, and the negative terminal of the lighting module LED1 is connected to the reference ground GND.

[0154] The above technical solution makes the lighting fixture more reasonable; it greatly improves the dimming performance of the LED1 lighting module, which can reach ±2%, and is low in cost. It also improves the light jitter during the dimming process of the traditional potentiometer RP1, and has a wide dimming range.

[0155] The same or similar parts between the various embodiments in this specification can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments.

[0156] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be defined by the scope of the claims.

Claims

1. A dimming control circuit for driving a lighting module (LED1), characterized in that, include: Power input terminal (1), which is used to connect to an external power source; The driving module (2) has a driving output terminal (201) and a feedback terminal (FB). The driving module (2) is connected to an external power source through the power input terminal (1) to obtain electrical energy, processes the electrical energy, and supplies power to the lighting module (LED1) through the driving output terminal (201). The driving module (2) is configured to control the voltage output of its driving output terminal (201) according to the voltage received by its feedback terminal (FB). The feedback module (3) has a feedback output terminal (301), which is connected to the feedback terminal (FB) of the drive module (2). The feedback module (3) is connected in series in the circuit where the lighting module (LED1) is located, and the feedback module (3) is configured to convert the current flowing through it into a corresponding feedback voltage signal and output it through the feedback output terminal (301). The adjustment module (4) has an adjustment output terminal (401), and the adjustment module (4) is configured to adjust the magnitude of the adjustment voltage signal output by the adjustment output terminal (401); And a voltage follower module (5), which includes a voltage follower (501) having a follower input terminal (5011) and a follower output terminal (5012). The follower input terminal (5011) of the voltage follower (501) is connected to the adjustment output terminal (401) of the adjustment module (4), and the follower output terminal of the voltage follower (501) is connected to the feedback module (3) to apply the voltage output by the follower output terminal to the feedback module (3).

2. The dimming control circuit according to claim 1, characterized in that: The adjustment module (4) includes a reference power supply (402) and a voltage adjustment component (403). The reference power supply (402) is used to provide a reference voltage. The voltage adjustment component (403) has a high potential terminal (4031), a low potential terminal (4032) and an adjustable output terminal (4033). The high potential terminal (4031) is connected to the reference power supply output positive terminal (4021) of the reference power supply (402). The low potential terminal (4032) is connected to the reference power supply output negative terminal (4022) of the reference power supply (402). The reference power supply output negative terminal (4022) of the reference power supply (402) is connected to reference ground (GND). The adjustable output terminal (4033) is configured to output a corresponding voltage divider value according to its position relative to the high potential terminal (4031) and the low potential terminal (4032), and the adjustable output terminal (4033) is formed as the adjustable output terminal (401).

3. The dimming control circuit according to claim 2, characterized in that: The voltage regulation component (403) employs a potentiometer (RP1), with the two ends of the potentiometer (RP1) forming the high potential end (4031) and the low potential end (4032) respectively, and the tap of the potentiometer (RP1) forming the adjustable output end (4033). The reference power supply (402) includes a voltage reference unit (4023), which has a positive output terminal (4021) and a negative output terminal (4022) of the reference power supply. The voltage reference unit (4023) is connected to the power input terminal (1) to receive the power supply voltage and outputs a reference voltage with a preset accuracy through the positive output terminal (4021) and the negative output terminal (4022) of the reference power supply. The voltage reference unit (4023) adopts a three-terminal adjustable precision parallel voltage regulator (U3). The anode of the three-terminal adjustable precision parallel voltage regulator (U3) is connected to the reference ground (GND), the cathode of the three-terminal adjustable precision parallel voltage regulator (U3) is connected to the power input terminal (1), the reference terminal of the three-terminal adjustable precision parallel voltage regulator (U3) is short-circuited with its cathode, the cathode of the three-terminal adjustable precision parallel voltage regulator (U3) is formed as the positive output terminal (4021) of the reference power supply, and the anode of the three-terminal adjustable precision parallel voltage regulator (U3) is formed as the negative output terminal (4022) of the reference power supply. The reference power supply (402) includes a seventh resistor (R7), and the power input terminal (1) is connected to the voltage reference unit (4023) through the seventh resistor (R7); The reference power supply (402) includes a seventh capacitor (C7), one end of which is connected to the connection between the power input terminal (1) and the voltage reference unit (4023), and the other end of which is connected to the reference ground (GND). The reference power supply (402) includes an eighth capacitor (C8), one end of which is connected to the positive output terminal (4021) of the reference power supply, and the other end of which is connected to the reference ground (GND).

4. The dimming control circuit according to claim 1, characterized in that: The drive module (2) is used to boost electrical energy and then supply it to the lighting module (LED1) through the drive output terminal (201); The driving module (2) includes a boost unit (U1), an energy storage inductor (L1), and a first diode (D1). The power input terminal (1) is connected to the power input terminal (VDD) of the boost unit (U1) and the first terminal (L1-1) of the energy storage inductor (L1). The second terminal (L1-2) of the energy storage inductor (L1) is connected to the anode of the first diode (D1). The cathode of the first diode (D1) is connected to the driving output terminal (201). The boost unit (U1) has the feedback terminal (FB). The boost unit (U1) is configured to control whether the second terminal (L1-2) of the energy storage inductor (L1) is connected to the reference ground (GND) in a pulse width modulation manner, and to control the charging and discharging process of the energy storage inductor (L1) by adjusting the duty cycle through the feedback voltage signal received by its feedback terminal (FB).

5. The dimming control circuit according to claim 4, characterized in that: The boost unit (U1) has a first boost switch terminal (DRV) and a second boost switch terminal (SE). The first boost switch terminal (DRV) is connected to the second terminal (L1-2) of the energy storage inductor (L1), and the second boost switch terminal (SE) is connected to the reference ground (GND). Furthermore, the boost unit (U1) is configured to control the switching between the first boost switch terminal (DRV) and the second boost switch terminal (SE) in a pulse width modulation manner.

6. The dimming control circuit according to claim 5, characterized in that: The drive module (2) includes a current-limiting resistor (RS1), the boost unit (U1) has a current sampling terminal (CS), one end of the current-limiting resistor (RS1) is connected to reference ground (GND) and the other end is connected to the current sampling terminal (CS); and the drive module (2) is configured to control and adjust the duty cycle according to the voltage magnitude collected by its current sampling terminal (CS) to limit the output power of the drive module (2); The drive module (2) includes a turn-off time setting capacitor (C3), the boost unit (U1) has a turn-off time setting terminal (Toff), the turn-off time setting terminal (Toff) is connected to one end of the turn-off time setting capacitor (C3), and the other end of the turn-off time setting capacitor (C3) is connected to the reference ground (GND). The drive module (2) includes a frequency compensation capacitor (C4), the boost unit (U1) has a frequency compensation terminal (COMP), the frequency compensation terminal (COMP) is connected to one end of the frequency compensation capacitor (C4), and the other end of the frequency compensation capacitor (C4) is connected to the reference ground (GND). The boost unit (U1) has an enable terminal (EN), which is connected to the power input terminal (1). The boost unit (U1) has a ground terminal (G), which is connected to the reference ground (GND). The boost unit (U1) employs a boost-type constant current driver, which uses an SL8530B chip. Pin 1 of the SL8530B chip is configured as the ground terminal (G), pin 2 as the enable terminal (EN), pin 3 as the frequency compensation terminal (COMP), pin 4 as the feedback terminal (FB), pin 5 as the first boost switch terminal (DRV), pin 6 as the second boost switch terminal (SE) and the current sampling terminal (CS), pin 7 as the off-time setting terminal (Toff), and pin 8 as the power input terminal (VDD).

7. The dimming control circuit according to claim 1, characterized in that: The voltage follower (501) employs an operational amplifier (U2), which has a non-inverting input terminal (U2-1), an inverting input terminal (U2-2), and an operational amplifier output terminal (U2-3). The inverting input terminal (U2-2) is connected to the operational amplifier output terminal (U2-3). The non-inverting input terminal (U2-1) is formed as the follower input terminal (5011), and the operational amplifier output terminal (U2-3) is formed as the follower output terminal (5012). The operational amplifier output terminal (U2-3) of the operational amplifier (U2) is output to the outside through the fifth resistor (R5); The positive terminal of the operational amplifier (U2) is connected to the power input terminal (1) through the sixth resistor (R6), and the negative terminal of the operational amplifier (U2) is connected to the reference ground (GND). The voltage follower module (5) also includes a protection diode (ZD2) for providing input voltage clamping protection. The cathode of the protection diode (ZD2) is connected to the positive terminal of the power supply of the operational amplifier (U2), and the positive terminal of the protection diode (ZD2) is connected to the reference ground (GND). The voltage follower module (5) also includes a sixth capacitor (C6) for filtering. One end of the sixth capacitor (C6) is connected to the positive power supply of the operational amplifier (U2), and the other end of the sixth capacitor (C6) is connected to the negative power supply of the operational amplifier (U2). The protection diode (ZD2) is a Zener diode; The operational amplifier (U2) uses the LM358 chip.

8. The dimming control circuit according to claim 1, characterized in that: The drive module (2) has an internal reference voltage and is configured to: reduce the voltage output of its drive output terminal (201) when the feedback voltage signal received by the feedback terminal (FB) is higher than its internal reference voltage, and increase the voltage output of its drive output terminal (201) when the feedback voltage signal received by the feedback terminal (FB) is lower than its internal reference voltage. The drive module (2) includes a protection unit (202), which is connected to the drive output terminal (201) and the feedback terminal (FB). The protection unit (202) is configured to: compare the voltage output by the drive output terminal (201) with its internal voltage threshold, and pull the voltage of the feedback terminal (FB) to be greater than the internal reference voltage of the drive module (2) when the voltage output by the drive output terminal (201) is greater than its internal voltage threshold. The protection unit (202) includes a first Zener diode (ZD1), the anode of the first Zener diode (ZD1) is connected to the feedback terminal (FB), and the cathode of the first Zener diode (ZD1) is connected to the drive output terminal (201). The drive module (2) includes a short-circuit protection unit (203) for short-circuit protection. The short-circuit protection unit (203) includes a second diode (D2). The anode of the second diode (D2) is connected to the cathode of the lighting module (LED1), and the cathode of the second diode (D2) is connected to the reference ground (GND).

9. The dimming control circuit according to claim 4, characterized in that: The feedback module (3) includes a feedback resistor (RS2), one end of which is connected to the negative terminal of the lighting module (LED1), and the other end of which is connected to the reference ground (GND). The connection between the feedback resistor (RS2) and the negative terminal of the lighting module (LED1) forms the feedback output terminal (301). The driving module (2) includes a fourth resistor (R4) and a fifth capacitor (C5). One end of the fifth capacitor (C5) is connected to the feedback terminal (FB), and the other end of the fifth capacitor (C5) is connected to the reference ground (GND). The feedback output terminal (301) of the feedback module (3) is connected to the feedback terminal (FB) through the fourth resistor (R4). The voltage follower (501) is connected to the end of the fourth resistor (R4) that is connected to the feedback terminal (FB). The drive module (2) includes a first resistor (R1) and a second capacitor (C2). The power input terminal (VDD) is connected to the power input terminal (1) through the first resistor (R1). The enable terminal (EN) of the boost unit (U1) is connected to the power input terminal (1) through the first resistor (R1). One end of the first resistor (R1) connected to the power input terminal (1) and the enable terminal (EN) is connected to one end of the second capacitor (C2). The other end of the second capacitor (C2) is connected to the reference ground (GND). The drive module (2) includes a second resistor (R2), and the enable terminal (EN) is connected to the first resistor (R1) through the second resistor (R2); The drive module (2) includes an output filter capacitor (EC2), one end of which is connected to the drive output terminal (201), and the other end of which is connected to the reference ground (GND). The output filter capacitor (EC2) is an electrolytic capacitor; The drive module (2) includes a first input filter capacitor (EC1) and / or a second input filter capacitor (C1). One end of the first input filter capacitor (EC1) is connected to the power input terminal (1), and the other end of the first input filter capacitor (EC1) is connected to the reference ground (GND). One end of the second input filter capacitor (C1) is connected to the power input terminal (1), and the other end of the second input filter capacitor (C1) is connected to the reference ground (GND). The first input filter capacitor (EC1) is an electrolytic capacitor, and the second input filter capacitor (C1) is a regular capacitor; The drive module (2) includes a third resistor (R3), one end of which is connected to the drive output terminal (201), and the other end of which is connected to the reference ground (GND).

10. A lighting fixture, characterized in that: The device includes a dimming control circuit as described in any one of claims 1 to 9, and an illumination module (LED1) for emitting light, wherein the positive terminal of the illumination module (LED1) is connected to the drive output terminal (201), and the negative terminal of the illumination module (LED1) is connected to the reference ground (GND).

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