LED control circuit and LED dimming method

Abstract

The embodiment of the invention relates to the technical field of circuit design, and discloses an LED control circuit and an LED dimming method.The LED control circuit comprises a sampling unit, a control unit and a switch unit; the input end of the sampling unit is connected with a voltage source, and the sampling unit is used for receiving an input voltage and inputting a first voltage obtained by dividing the input voltage to the control unit; the control unit is used for receiving the first voltage, generating a PWM control signal of a duty ratio corresponding to the first voltage, and inputting the PWM control signal to the switch unit; and the output end of the switch unit is connected with the LED load, and the switch unit is used for adjusting the current passing through the LED load according to the duty ratio of the PWM control signal so as to realize the brightness adjustment of the LED load.

Description

Technical Field

[0001] The present application relates to the technical field of circuit design, and in particular to an LED control circuit and an LED dimming method. Background Art

[0002] With the development of the times and the advancement of science and technology, light emitting diodes (LEDs) have been widely used in various fields of life and production due to their advantages such as high efficiency, energy saving and long life, such as general lighting, medical equipment, traffic signals and other scenarios.

[0003] In an LED dimming circuit, an additional dimming line is usually required to control the brightness of the LED, but this method increases the complexity of the circuit and the wiring cost. Summary of the invention

[0004] The embodiment of the present application provides an LED control circuit to solve the problem of high complexity of the LED control circuit in the prior art.

[0005] In order to solve the above problems, an embodiment of the present application discloses an LED control circuit, which is characterized by comprising: a sampling unit, a control unit, and a switch unit; The input end of the sampling unit is connected to a voltage source, and is used to receive an input voltage, and input a first voltage after the input voltage is divided into the control unit; The control unit is used to receive the first voltage, generate a pulse width modulation (PWM) control signal with a duty cycle corresponding to the first voltage, and input the PWM control signal to the switch unit; The output end of the switch unit is connected to a light emitting diode (LED) load, and is used to adjust the current passing through the LED load according to the duty cycle of the PWM control signal, thereby achieving brightness adjustment of the LED load.

[0006] The embodiment of the present application further discloses an LED dimming method, which is applied to the above-mentioned LED control circuit, and the method includes: receiving an input voltage through a sampling unit of the LED control circuit, and inputting a first voltage obtained by dividing the input voltage into a control unit of the LED control circuit; Receiving the first voltage through the control unit, generating a PWM control signal having a duty cycle corresponding to the first voltage, and inputting the PWM control signal into the switch unit of the LED control circuit; The PWM control signal is received by the switch unit, and the current passing through the LED load is adjusted according to the duty cycle of the PWM control signal, so as to adjust the brightness of the LED load.

[0007] The present application also discloses an LED dimming device, which includes: A first processing module, configured to receive an input voltage through a sampling unit of the LED control circuit, and input a first voltage obtained by dividing the input voltage into a control unit of the LED control circuit; a second processing module, configured to receive the first voltage through the control unit, generate a PWM control signal having a duty cycle corresponding to the first voltage, and input the PWM control signal to a switch unit of the LED control circuit; The third processing module is used to receive the PWM control signal through the switch unit, and adjust the current passing through the LED load according to the duty cycle of the PWM control signal to achieve brightness adjustment of the LED load.

[0008] An embodiment of the present application also discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, one or more of the methods described in the embodiments of the present application are implemented.

[0009] The embodiments of the present application further disclose a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, one or more methods described in the embodiments of the present application are implemented.

[0010] The embodiments of the present application also disclose a computer program product, including a computer program, which, when executed by a processor, implements one or more of the methods described in the embodiments of the present application.

[0011] It can be seen from the above technical solution that the LED control circuit provided in the embodiment of the present application includes: a sampling unit, a control unit and a switch unit. The sampling unit is connected to a voltage source, and is used to receive an input voltage and divide it to form a first voltage to input to the control unit; the control unit generates a PWM control signal with a duty cycle corresponding to the voltage according to the received first voltage, and outputs the signal to the switch unit; the switch unit adjusts the current passing through the LED load by adjusting the duty cycle of the PWM signal, thereby achieving precise control of the LED brightness. Through this design, the circuit only needs to use the bus voltage for sampling and dimming signal transmission, without the need for additional dimming lines, which not only simplifies the hardware structure and reduces the wiring complexity and cost, but also improves the reliability and adaptability of the system, and is suitable for the intelligent dimming needs of various application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 One of the structural schematic diagrams of the LED control circuit provided in the embodiment of the present application; Figure 2 The second structural diagram of the LED control circuit provided in the embodiment of the present application; Figure 3 The third structural diagram of the LED control circuit provided in the embodiment of the present application; Figure 4 A flowchart of an LED dimming method provided in an embodiment of the present application; Figure 5 A schematic diagram of the structure of an LED dimming device provided in an embodiment of the present application; Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0013] The embodiments of the present application are described below in conjunction with the drawings in the present application. It should be understood that the implementation methods described below in conjunction with the drawings are exemplary descriptions for explaining the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions of the embodiments of the present application.

[0014] Those skilled in the art will appreciate that, unless specifically stated, the singular forms "one", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the terms "including" and "comprising" used in the embodiments of the present application refer to that the corresponding features can be implemented as the presented features, information, data, steps, operations, elements and / or components, but do not exclude the implementation as other features, information, data, steps, operations, elements, components and / or combinations thereof supported by the technical field. It should be understood that when we say that an element is "connected" or "coupled" to another element, the one element may be directly connected or coupled to the other element, or it may refer to that the one element and the other element establish a connection relationship through an intermediate element. In addition, the "connection" or "coupling" used here may include wireless connection or wireless coupling. The term "multiple" refers to two or more than two. In view of this, "multiple" may also be understood as "at least two" in the embodiments of the present application. The term "and / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0015] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0016] The LED control circuit provided in the embodiment of the present application is widely used in various scenarios that require efficient and precise dimming, such as smart lighting, industrial lighting, medical equipment lighting, traffic lights, advertising display screens, and other LED application systems. In particular, in scenarios where strict requirements are placed on light intensity and dynamic brightness adjustment is required, the circuit exhibits superior adaptability and reliability. For example, in smart homes, users can achieve gentle changes in indoor lighting by adjusting the input voltage to meet different usage requirements; in industrial production, high-brightness LED lights can adjust brightness according to operating conditions to optimize energy consumption; in traffic lights, the circuit achieves real-time dynamic adjustment of brightness, improving the visibility and service life of the equipment.

[0017] However, the LED dimming method widely used in the prior art usually requires additional dimming wires to transmit control signals. This design has obvious defects: on the one hand, the additional dimming wire increases the wiring complexity of the circuit, which not only increases the design and construction costs, but also increases the difficulty of system maintenance; on the other hand, the dimming signal may be interfered during the transmission process, affecting the accuracy of dimming and causing unstable LED brightness adjustment. In addition, the existing dimming method is difficult to adapt to the needs of simplifying hardware and improving system reliability in different application scenarios.

[0018] The embodiment of the present application achieves the effect of accurately adjusting the LED brightness only through the bus by sampling the input bus voltage, generating a PWM control signal and adjusting the LED load current, without the need for additional dimming lines, thereby greatly simplifying the circuit design, reducing wiring and maintenance costs, and improving the reliability and applicability of the dimming system. This design not only optimizes the hardware structure, but also provides an efficient, economical and stable solution for intelligent lighting and related fields.

[0019] Figure 1 FIG. 1 is one of the structural diagrams of the LED control circuit according to the embodiment of the present application. Figure 1 The LED control circuit provided in the embodiment of the present application is explained and illustrated in detail. Figure 1 As shown, the LED control circuit includes: a sampling unit 1, a control unit 2, and a switch unit 3; The input end of the sampling unit 1 is connected to a voltage source, and is used to receive an input voltage, and input a first voltage after the input voltage is divided into the control unit; The control unit 2 is used to receive the first voltage, generate a pulse width modulation (PWM) control signal with a duty cycle corresponding to the first voltage, and input the PWM control signal to the switch unit 3; The output end of the switch unit 3 is connected to a light emitting diode (LED) load, and is used to adjust the current passing through the LED load according to the duty cycle of the PWM control signal, thereby adjusting the brightness of the LED load.

[0020] The LED control circuit provided in the embodiment of the present application is intended to solve the technical problems of complex wiring, serious interference problems and poor system adaptability caused by controlling the brightness of LEDs through additional dimming lines in the prior art. In modern lighting systems, LEDs are widely used in scenarios such as household lighting, industrial lighting, and traffic lights. The brightness adjustment function is an important requirement for improving user experience and optimizing energy consumption. However, existing dimming methods usually rely on additional dimming lines to transmit signals, which not only increases the complexity of hardware design and construction costs, but may also cause unstable dimming effects due to interference with transmission lines, making it difficult to meet the requirements of intelligent lighting and high-reliability scenarios. The LED control circuit of the present application simplifies the circuit structure through innovative design, while improving the dimming stability and adaptability of the system.

[0021] Specifically, the LED control circuit provided in the embodiment of the present application includes three parts: a sampling unit, a control unit and a switch unit. Among them, the sampling unit is connected to the voltage source, and the first voltage after voltage division is input as a signal to the control unit by dividing the input voltage. Among them, the sampling unit includes but is not limited to resistors, and voltage division is the process of distributing voltage through resistors. By adjusting the resistance value of the resistor in the sampling unit, the input voltage can be accurately divided into a low voltage range that the control unit can handle. For example, if the bus input voltage is 24V, and the control unit can only receive a 0-5V signal, the voltage output after voltage division can be ensured to fall within the range of 0-5V by selecting a suitable resistor.

[0022] Further, the control unit receives the first voltage provided by the sampling unit and converts it into a pulse width modulation (PWM) control signal corresponding to the duty cycle, thereby realizing a dynamic correspondence between the brightness and the input voltage. Among them, PWM is a method for transmitting control signals, which represents different control information by adjusting the ratio of the "high level duration" and the "low level duration" of a square wave. A PWM control signal includes a frequency parameter and a duty cycle parameter; wherein the frequency indicates how long the cycle of the PWM control signal is (the total time of the high level + the low level); the duty cycle indicates the percentage of the high level duration in the entire cycle in one cycle. For example, assuming that the cycle of the PWM control signal is 10ms: if the high level duration is 5ms and the low level duration is 5ms, the duty cycle is 50%; if the high level duration is 2ms, the duty cycle is 20%. In the embodiment of the present application, the duty cycle of the PWM control signal is the core parameter for adjusting the brightness of the LED load. The duty cycle reflects the "workload" of the PWM control signal. The higher the duty cycle, the more time the signal "transfers energy", and the greater the impact on the LED load. For example: a duty cycle of 10% means that energy is transmitted only 10% of the time in a cycle; a duty cycle of 90% means that energy is transmitted 90% of the time in a cycle. By adjusting the duty cycle of the PWM control signal, the brightness of the LED can be accurately controlled. In an embodiment of the present application, the control unit generates a corresponding PWM control signal by detecting changes in the bus input voltage, and the duty cycle is in a corresponding relationship with the bus voltage. For example, when the input voltage is high, the control unit generates a PWM control signal with a high duty cycle (such as an 80% duty cycle), thereby increasing the current passing through the LED and improving the brightness; when the input voltage is low, the control unit generates a PWM control signal with a low duty cycle (such as a 20% duty cycle), reducing the current passing through the LED and reducing the brightness. Therefore, the duty cycle of the PWM control signal can be accurately adjusted only by changes in the bus input voltage, thereby achieving LED brightness adjustment.

[0023] Specifically, through the control of the PWM signal, the switch unit adjusts the current flowing through the LED load, thereby achieving high-precision adjustment of the LED brightness. For example, if the duty cycle is 50%, the switch unit is turned on half of the time, and the LED current is half of the rated current; if the duty cycle is 80%, the switch unit is turned on most of the time, and the LED current is close to the rated current. Therefore, the higher the duty cycle, the greater the average current of the LED, and the higher the brightness. This design not only greatly simplifies the hardware structure of the dimming system, but also improves the dimming response speed and control accuracy.

[0024] The LED control circuit provided in the embodiment of the present application effectively solves the problems of high complexity and poor stability of the dimming system in the prior art by directly sampling the bus voltage, generating PWM signals and accurately adjusting the current flowing through the LED load, and provides an efficient, low-cost and highly adaptable LED brightness adjustment solution, which is particularly suitable for modern intelligent lighting and multi-scenario application requirements.

[0025] Figure 2 FIG. 2 is a second structural diagram of an LED driving circuit according to an embodiment of the present application. Figure 2 As shown, the LED driving circuit shown in the embodiment of the present application includes: a sampling unit 1, a control unit 2, a switch unit 3, a voltage regulating unit 4, and a filter output unit; The input end of the sampling unit 1 is connected to a voltage source, and is used to receive an input voltage, and input a first voltage after the input voltage is divided into the control unit 2; The control unit 2 is used to receive the first voltage, generate a pulse width modulation (PWM) control signal with a duty cycle corresponding to the first voltage, and input the PWM control signal to the switch unit 3; The output end of the switch unit 3 is connected to a light emitting diode (LED) load, and is used to adjust the current passing through the LED load according to the duty cycle of the PWM control signal, thereby adjusting the brightness of the LED load.

[0026] In some embodiments, the switch unit 3 is further used to input a feedback current of the LED load to the control unit 2 , and the control unit 2 detects a current passing through the LED load according to the feedback current.

[0027] In the embodiment of the present application, the switch unit is not only used to control the current of the LED load, but also to input the feedback current passing through the LED into the control unit. By collecting the feedback current, the control unit can detect the actual current passing through the LED in real time. This real-time feedback mechanism can help the control unit accurately adjust the duty cycle of the PWM control signal to ensure that the actual current is consistent with the target current. For example, through the detection of the feedback current, the control unit can dynamically adjust the PWM signal to eliminate possible errors (such as current deviations caused by input voltage fluctuations or component parameter changes) to ensure that the brightness of the LED is more uniform and stable.

[0028] In some embodiments, after receiving the feedback current of the LED load, the control unit 2 generates a corresponding output frequency adjustment signal according to the feedback current, and inputs the output frequency adjustment signal to the voltage regulation unit 4; The output end of the voltage regulating unit 4 is connected to the LED load; the voltage regulating unit 4 adjusts the voltage passing through the LED load according to the frequency adjustment signal.

[0029] In an embodiment of the present application, after receiving the feedback current, the control unit can generate an output frequency adjustment signal according to the feedback current, and input the signal to the voltage regulating unit. The voltage regulating unit is connected to the LED load through the filter output unit, and its main function is to adjust the output voltage according to the frequency adjustment signal of the control unit. Among them, the voltage range adjusted by the voltage regulating unit can vary according to the actual application scenario and the operating parameters of the LED load, and no specific restrictions are made here. In general, the purpose of adjusting the voltage is to ensure that the operating current of the LED load is always within a safe and target range. When the feedback current is too large, the control unit will reduce the frequency of the frequency adjustment signal, thereby reducing the output voltage of the voltage regulating unit, and ultimately reducing the current of the LED; conversely, if the feedback current is too small, the frequency of the frequency adjustment signal will increase, thereby increasing the output voltage and current.

[0030] In some embodiments, between the voltage regulating unit 4 and the LED load, further included is: the filter output unit 5; The filter output unit 5 is used to receive the DC voltage output by the voltage regulating unit 4, and after filtering the DC voltage, output a constant current to the LED load.

[0031] In the embodiment of the present application, in order to further optimize the voltage output quality, a filter output unit is provided between the output end of the voltage regulating unit and the LED load. The filter output unit is mainly composed of passive components such as inductors and capacitors, and is used to filter the DC voltage output by the voltage regulating unit, eliminate the high-frequency noise and ripples generated by the switch operation, and output a more stable constant current to the LED load.

[0032] Specifically, the output of the voltage regulator may contain a certain amount of ripple voltage, which will cause the LED current to fluctuate, thus affecting the stability of the brightness. The filter unit reduces these fluctuations to a minimum by smoothing the voltage. In addition, the filter unit can also prevent high-frequency noise from being transmitted to the LED load, preventing adverse effects on luminous efficiency and service life.

[0033] In some embodiments, the sampling unit includes a first resistor, a second resistor, a first operational amplifier, and a second operational amplifier; Among them, the first resistor and the second resistor are connected in series, and are used to receive an input voltage and perform voltage division processing on the input voltage; the first operational amplifier is connected in parallel to the two ends of the second resistor, and the output end of the first operational amplifier is connected to the input end of the second operational amplifier. The first operational amplifier and the second operational amplifier are used to receive the voltage output by the first resistor and the second resistor, and input the voltage to the control unit after gain adjustment.

[0034] In the embodiment of the present application, the first resistor may be Figure 3 The second resistor R16 in can be Figure 3 R17 in the first operational amplifier can be Figure 3 The second operational amplifier in U2A can be Figure 3 In U2B, the control unit can be Figure 3 U1 in.

[0035] In some embodiments, the switch unit is a metal-oxide-semiconductor field-effect transistor (MOSFET). For example, the switch unit may be Figure 3 Q1 in.

[0036] In some embodiments, the filter output unit includes a diode, a filter capacitor and a filter inductor; The diode, the filter capacitor and the filter inductor are connected in series to filter the DC voltage.

[0037] In the embodiment of the present application, the diode of the filter output unit can be Figure 3 D5, D6, D7 in the filter capacitor can be Figure 3 The filter inductor C3 can be Figure 3 LF1 in.

[0038] Figure 3 This is the third structural schematic diagram of the LED driving circuit provided in the embodiment of the present application.

[0039] like Figure 3 As shown, the LED driving circuit shown in the embodiment of the present application includes: a fuse F1, a diode (D1-D10), a capacitor (C1, C2, C3, C4, C5, C6, C7), a resistor (R1-R18), an operational amplifier (U2A, U2B), a transistor (Q1, Q2), a control chip (U1), a voltage regulator (T1), a voltage regulator diode (B1, B2), a filter inductor (LF1), and a positive and negative electrode of an LED load.

[0040] Among them, the LED drive circuit includes input power supply part, start-up control part, PWM control part, feedback and voltage regulation part, LED load and dimming part, overcurrent protection and compensation part. The contents of each part will be explained below.

[0041] 1. Input power supply The power supply voltage is input into the circuit through input+ and input-. Input+ is first connected to F1 (fuse) for circuit protection. When overcurrent or short circuit occurs, F1 will blow to prevent damage to the circuit. The back end of F1 is connected to D10 (diode), which is used to prevent the power supply from being connected in reverse. If the input voltage polarity is reversed, D10 prevents reverse current from flowing into the circuit. The back end of D10 is connected to C1 (capacitor), which is used to filter out high-frequency noise in the input voltage and make the input voltage more stable. At the same time, the output of D10 also diverts part of the current through R2 (resistor) for subsequent startup control and control chip power supply.

[0042] 2. Startup control part (with U1, U2A and Q1 as the core) The other end of R2 is connected to the positive input (+) of U2A (operational amplifier). The negative input (−) of U2A is connected to input− through R17 (resistor), forming a voltage divider network to set a reference voltage. U2A compares the voltages at the positive and negative input terminals: when the positive input voltage is greater than the negative input voltage (that is, the input voltage reaches a certain value), the output of U2A becomes a high level. The output of U2A is connected to the base of Q1 (transistor) through R11 (resistor), driving Q1 to turn on. The collector of Q1 is connected to the Zener diode B1 and R5 (resistor). The Zener diode B1 provides a stable voltage to power the subsequent circuits. The conduction of Q1 enables the power supply of the control chip U1 to be started, so that it starts working.

[0043] 3. PWM control part (with U1 as the core) U1 (integrated control chip) is the core of the entire circuit. It is mainly responsible for: outputting PWM signals, adjusting LED brightness, detecting feedback signals, controlling output current and voltage, and providing overcurrent and overvoltage protection. Among them, the VDD pin of U1 is powered by R2 and the voltage regulator circuit, and starts to output PWM signals after startup. The GATE pin of U1 outputs a PWM signal to drive the power switch Q2 (transistor or MOSFET). The collector of Q2 is connected to the primary coil of the transformer T1, and the primary current is controlled by the switching action. Transformer T1 converts the primary voltage and current to the secondary and provides it to the LED load.

[0044] 4. Feedback and voltage regulation part (with U2B and output diode as the core) The secondary output voltage of transformer T1 is converted into a DC voltage through rectifier diodes D6 and D7. The rectified DC is filtered by C3 (capacitor) to eliminate the ripple voltage and obtain a stable DC supply to the LED load. At the same time, part of the voltage of the secondary output is provided to the feedback circuit through D5 (diode) and Zener diode B2. B2 is used to stabilize the feedback voltage and avoid output voltage fluctuations. The feedback voltage is filtered by R6 (resistor) and C4 (capacitor) and connected to the input terminal (+) of U2B. U2B (operational amplifier) ​​compares the feedback voltage with the internal reference voltage: if the feedback voltage exceeds the set value, the output signal of U2B is fed back to U1 through R13 (resistor), adjusting the PWM duty cycle and reducing the output current. If the feedback voltage is lower than the set value, U2B adjusts the signal to change in the opposite direction to increase the output current.

[0045] 5. LED load and dimming part The filtered DC current flows to the LED load through the current limiting resistor R10. R10 limits the current through the LED to prevent damage to the LED. The LED brightness is adjusted by the control chip U1: by changing the PWM signal duty cycle, the on-time of the power switch Q2 is controlled, and then the current through the LED is changed to achieve brightness adjustment.

[0046] 6. Overcurrent protection and compensation part D3 (diode) and R9 (resistor) form a detection circuit to monitor the working status of transformer T1. When the primary current is too large, the detection signal of D3 is input to the protection pin of the control chip U1 through R9 and C5, triggering the overcurrent protection mechanism to prevent damage to the circuit.

[0047] The present application also provides an LED dimming method. Figure 4 One of the flow charts of the undervoltage protection method provided in the embodiment of the present application is shown in FIG. Figure 4 , the method may include the following steps: Step 401: receiving an input voltage through a sampling unit of the LED control circuit, and inputting a first voltage obtained by dividing the input voltage into a control unit of the LED control circuit.

[0048] In the embodiment of the present application, the main function of the sampling unit is to divide the input voltage to obtain a first voltage proportional to the input voltage. Specifically, the sampling unit divides the input voltage appropriately through a pair of resistors (or other voltage-dividing components) to convert the voltage into a lower signal suitable for subsequent processing. This first voltage after voltage division will be sent to the control unit as an input signal. Through voltage division, the system can accurately adjust the subsequent brightness control according to the change of the actual input voltage without directly processing the high voltage.

[0049] Step 402: Receive the first voltage through the control unit, generate a PWM control signal with a duty cycle corresponding to the first voltage, and input the PWM control signal to the switch unit of the LED control circuit.

[0050] In the embodiment of the present application, the function of the control unit is to receive the first voltage after voltage division, and generate a corresponding PWM control signal based on the voltage. The core of the PWM control signal is to control the output of the signal by adjusting the duty cycle. The duty cycle refers to the time ratio of the signal "on" state within a cycle, which directly determines the current output of the LED load, thereby adjusting the brightness of the LED. Through precise control, the control unit can adjust the duty cycle of the PWM signal according to the change of the input voltage, so that the brightness of the LED changes with the change of the input voltage. The embodiment of the present application realizes precise adjustment of the brightness of the LED through the PWM control signal, so that a single voltage source can realize the brightness adjustment of the LED load without the need for an additional dimming circuit, thereby reducing the complexity and cost of the system design.

[0051] Step 403: receiving the PWM control signal through the switch unit, and adjusting the current passing through the LED load according to the duty cycle of the PWM control signal to adjust the brightness of the LED load.

[0052] In the embodiment of the present application, after the switch unit receives the PWM control signal transmitted by the control unit, it adjusts the current passing through the LED load according to the duty cycle of the PWM signal. Specifically, the switch unit controls the amount of current flowing into the LED load through periodic switching actions. When the duty cycle of the PWM signal is relatively large, the current of the LED load is relatively large, and the brightness of the LED is also relatively high; conversely, when the duty cycle of the PWM signal is relatively small, the current of the LED load is relatively small, and the brightness of the LED is also relatively low. In this way, the brightness of the LED can be smoothly adjusted without the need for additional complex circuit design. Under the condition of the same voltage transmission ratio, the circuit topology of the embodiment of the present application can operate under more ideal duty cycle conditions, thereby improving power supply stability and power supply efficiency.

[0053] In some embodiments, the method further comprises: The control unit receives the feedback current of the LED load input by the switch unit, and generates a corresponding output frequency adjustment signal according to the magnitude of the feedback current; The frequency adjustment signal is received by a voltage adjustment unit of the LED control circuit, and the voltage passing through the LED load is adjusted according to the frequency adjustment signal.

[0054] In the embodiment of the present application, the control unit is not only responsible for generating the PWM control signal, but also further monitors and adjusts the current by receiving the feedback current of the LED load from the switch unit. When the current of the LED load changes, the control unit can receive the feedback signal in real time and generate a corresponding frequency adjustment signal according to the magnitude of the feedback current. This signal is used to adjust the output of the voltage regulating unit to achieve accurate regulation of the LED load voltage.

[0055] Specifically, the voltage regulator receives the frequency adjustment signal and adjusts the output voltage to keep the current of the LED load within a predetermined range. By adjusting the LED load voltage, the voltage regulator can ensure the stable operation of the LED load, avoid damage to the LED due to unstable or excessive voltage, and ensure smooth brightness adjustment.

[0056] Nowadays, LED driver power supply technology is becoming more and more mature, and can be generally divided into single-stage and two-stage types. The single-stage LED driver power supply topology includes a buck converter (Buck), a buck-boost converter (Buck-boost), a flyback converter (Fly-back), etc. It has a simple structure, is easy to control, and has a low cost, but its power factor is low and the output current ripple is large, which affects the luminous quality of the LED. The two-stage LED driver power supply topology is divided into a front-stage power factor correction (Power Factor Correction, PFC) module and a rear-stage DC-DC converter (DC-DC) module. The structure is more complex than the single-stage type, the control strategy is more complicated, and the relative cost is higher. However, its advantages are that the power factor will be relatively high and the output current ripple is relatively low. In AC power supply situations, it can better meet the harmonic requirements of IEC 61000-3-2. The embodiment of the present application can further optimize the adjustment process of LED current and voltage by combining feedback current with frequency adjustment signals, and the output current ripple is low, which can achieve constant current output, meet the requirements of LED driver power supply, and make LED brightness adjustment more accurate and stable. At the same time, the feedback mechanism can ensure that the LED operates within the optimal voltage range, effectively avoiding overvoltage or undervoltage, and improving the reliability of the system and the service life of the LED. This feedback control mechanism makes the adjustment process more intelligent, can respond to load changes in real time, and improves the dimming accuracy and circuit efficiency. Based on the same principle as the method provided in the embodiment of the present application, the embodiment of the present application also provides an LED dimming device, such as Figure 5 As shown, the device comprises: A first processing module 1, configured to receive an input voltage through a sampling unit of the LED control circuit, and input a first voltage obtained by dividing the input voltage into a control unit of the LED control circuit; A second processing module 2, configured to receive the first voltage through the control unit, generate a PWM control signal having a duty cycle corresponding to the first voltage, and input the PWM control signal to a switch unit of the LED control circuit; The third processing module 3 is used to receive the PWM control signal through the switch unit, and adjust the current passing through the LED load according to the duty cycle of the PWM control signal to achieve brightness adjustment of the LED load.

[0057] The LED dimming device provided in the embodiment of the present application can achieve Figure 4 To avoid repetition, the various processes implemented in the method embodiment are not described here.

[0058] The LED dimming device provided by the present application has a sampling unit connected to a voltage source, which is used to receive an input voltage and divide it into a first voltage to input to a control unit; the control unit generates a PWM control signal with a duty cycle corresponding to the voltage according to the received first voltage, and outputs the signal to the switch unit; the switch unit adjusts the current through the LED load by adjusting the duty cycle of the PWM signal, thereby achieving precise control of the LED brightness. Through this design, the circuit only needs to use the bus voltage for sampling and dimming signal transmission, without the need for additional dimming lines, which not only simplifies the hardware structure, reduces the wiring complexity and cost, but also improves the reliability and adaptability of the system, and is suitable for the intelligent dimming needs of various application scenarios.

[0059] The LED dimming device of the embodiment of the present application can execute the LED dimming method provided in the embodiment of the present application, and the implementation principle is similar. The actions performed by each module and unit in the LED dimming device in each embodiment of the present application correspond to the steps in the LED dimming method in each embodiment of the present application. For the detailed functional description of each module of the LED dimming device, please refer to the description in the corresponding LED dimming method shown in the previous text, and will not be repeated here.

[0060] Based on the same principle as the method shown in the embodiment of the present application, the embodiment of the present application also provides an electronic device, which may include but is not limited to: a processor and a memory; a memory for storing a computer program; a processor for executing the LED dimming method shown in any optional embodiment of the present application by calling a computer program. Compared with the prior art, the LED dimming method provided by the present application receives an input voltage through a sampling unit of the LED control circuit, and inputs a first voltage after the input voltage is divided into a control unit of the LED control circuit; receives the first voltage through the control unit, generates a PWM control signal corresponding to the duty cycle of the first voltage, and inputs the PWM control signal into the switch unit of the LED control circuit; receives the PWM control signal through the switch unit, and adjusts the current passing through the LED load according to the duty cycle of the PWM control signal to achieve brightness adjustment of the LED load.

[0061] In an optional embodiment, an electronic device is also provided, such as Figure 6 As shown, Figure 6 The electronic device 6000 shown includes: a processor 6001 and a memory 6003. The processor 6001 and the memory 6003 are connected, such as through a bus 6002. Optionally, the electronic device 6000 may also include a transceiver 6004, which may be used for data interaction between the electronic device and other electronic devices, such as data transmission and / or data reception. It should be noted that in actual applications, the transceiver 6004 is not limited to one, and the structure of the electronic device 6000 does not constitute a limitation on the embodiments of the present application.

[0062] Processor 6001 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It may implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. Processor 6001 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0063] The bus 6002 may include a path to transmit information between the above components. The bus 6002 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus. The bus 6002 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0064] The memory 6003 may be a ROM (Read Only Memory) or other types of static storage devices that can store static information and instructions, a RAM (Random Access Memory) or other types of dynamic storage devices that can store information and instructions, or an EEPROM (Electrically Erasable Programmable Read Only Memory), a CD-ROM (Compact Disc Read Only Memory) or other optical disk storage, optical disk storage (including compressed optical disk, laser disk, optical disk, digital versatile disk, Blu-ray disk, etc.), magnetic disk storage medium, other magnetic storage devices, or any other medium that can be used to carry or store computer programs and can be read by a computer, without limitation herein.

[0065] The memory 6003 is used to store the computer program for executing the embodiment of the present application, and the execution is controlled by the processor 6001. The processor 6001 is used to execute the computer program stored in the memory 6003 to implement the steps shown in the above method embodiment.

[0066] Among them, electronic devices include but are not limited to: mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 6 The electronic device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0067] An embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps and corresponding contents of the aforementioned method embodiment can be implemented.

[0068] The embodiment of the present application also provides a computer program product, including a computer program, which can implement the steps and corresponding contents of the aforementioned method embodiment when executed by a processor.

[0069] The terms "first", "second", "third", "fourth", "1", "2", etc. (if any) in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that shown or described in the drawings.

[0070] It should be understood that, although each operation step is indicated by arrows in the flowchart of the embodiment of the present application, the implementation order of these steps is not limited to the order indicated by the arrows. Unless clearly stated herein, in some implementation scenarios of the embodiment of the present application, the implementation steps in each flowchart can be performed in other orders according to demand. In addition, some or all of the steps in each flowchart may include multiple sub-steps or multiple stages based on actual implementation scenarios. Some or all of these sub-steps or stages may be executed at the same time, and each sub-step or stage in these sub-steps or stages may also be executed at different times respectively. In different scenarios of execution time, the execution order of these sub-steps or stages may be flexibly configured according to demand, and the embodiment of the present application does not limit this.

[0071] The above is only an optional implementation method for some implementation scenarios of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the technical concept of the solution of the present application, other similar implementation methods based on the technical ideas of the present application are also within the protection scope of the embodiments of the present application.

Claims

1. An LED control circuit, characterized in that: include: Sampling unit, control unit, switch unit; The input end of the sampling unit is connected to a voltage source, and is used to receive an input voltage, and input a first voltage after the input voltage is divided into the control unit; The control unit is used to receive the first voltage, generate a pulse width modulation (PWM) control signal with a duty cycle corresponding to the first voltage, and input the PWM control signal to the switch unit; The output end of the switch unit is connected to a light emitting diode (LED) load, and is used to adjust the current passing through the LED load according to the duty cycle of the PWM control signal, thereby achieving brightness adjustment of the LED load.

2. The LED control circuit according to claim 1, characterized in that: The switch unit is further used for inputting a feedback current of the LED load to the control unit, and the control unit detects a current passing through the LED load according to the feedback current.

3. The LED control circuit according to claim 2, characterized in that: The LED control circuit further includes: a voltage regulating unit; After receiving the feedback current of the LED load, the control unit generates a corresponding output frequency adjustment signal according to the feedback current, and inputs the output frequency adjustment signal to the voltage regulation unit; The output end of the voltage regulating unit is connected to the LED load; the voltage regulating unit regulates the voltage passing through the LED load according to the frequency regulation signal.

4. The LED control circuit according to claim 3, characterized in that: Between the voltage regulating unit and the LED load, it also includes: a filter output unit; The filter output unit is used to receive the DC voltage output by the voltage regulating unit, and after filtering the DC voltage, output a constant current to the LED load.

5. The LED control circuit according to any one of claims 1 to 4, characterized in that: The sampling unit includes a first resistor, a second resistor, a first operational amplifier and a second operational amplifier; Among them, the first resistor and the second resistor are connected in series, and are used to receive an input voltage and perform voltage division processing on the input voltage; the first operational amplifier is connected in parallel to the two ends of the second resistor, and the output end of the first operational amplifier is connected to the input end of the second operational amplifier. The first operational amplifier and the second operational amplifier are used to receive the voltage output by the first resistor and the second resistor, and input the voltage to the control unit after gain adjustment.

6. The LED control circuit according to any one of claims 1 to 4, characterized in that: The switch unit is a metal oxide semiconductor field effect transistor MOS tube.

7. The LED control circuit according to claim 4, characterized in that: The filter output unit includes a diode, a filter capacitor and a filter inductor; The diode, the filter capacitor and the filter inductor are connected in series to filter the DC voltage.

8. An LED dimming method, applied to the LED control circuit according to any one of claims 1 to 7, characterized in that: The method comprises: Receiving an input voltage through a sampling unit of the LED control circuit, and inputting a first voltage obtained by dividing the input voltage into a control unit of the LED control circuit; Receiving the first voltage through the control unit, generating a PWM control signal having a duty cycle corresponding to the first voltage, and inputting the PWM control signal into the switch unit of the LED control circuit; The PWM control signal is received by the switch unit, and the current passing through the LED load is adjusted according to the duty cycle of the PWM control signal, so as to adjust the brightness of the LED load.

9. The LED dimming method according to claim 8, characterized in that: The method further comprises: The control unit receives the feedback current of the LED load input by the switch unit, and generates a corresponding output frequency adjustment signal according to the magnitude of the feedback current; The frequency adjustment signal is received by a voltage adjustment unit of the LED control circuit, and the voltage passing through the LED load is adjusted according to the frequency adjustment signal.

10. An LED dimming device, characterized in that: include: A first processing module, configured to receive an input voltage through a sampling unit of the LED control circuit, and input a first voltage obtained by dividing the input voltage into a control unit of the LED control circuit; a second processing module, configured to receive the first voltage through the control unit, generate a PWM control signal having a duty cycle corresponding to the first voltage, and input the PWM control signal to a switch unit of the LED control circuit; The third processing module is used to receive the PWM control signal through the switch unit, and adjust the current passing through the LED load according to the duty cycle of the PWM control signal to achieve brightness adjustment of the LED load.

11. An electronic device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the method according to claim 8 or 9 is implemented when the processor executes the program.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to claim 8 or 9 is implemented.

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