LED dimming drive circuit

Abstract

The utility model relates to the technical field of electronic circuits, in particular to an LED (light-emitting diode) dimming drive circuit, which comprises an ACDC (alternating current-direct current) constant voltage module, an LED dimming drive module and a control module, the voltage reduction and stabilization power supply module reduces and stabilizes the voltage to 5V / 3.3 V and outputs the voltage; a Bluetooth module; the MCU dimming control module is used for mixing and processing the Bluetooth dimming control signal and the knob dimming control signal and then outputting two paths of PWM1 and PWM2 dimming signals of which the sum is 100%; the analog and PWM dimming conversion module is used for correspondingly dimming by using analog voltage or PWM when the LED is in high brightness or low brightness; and the DCDC constant current module is used for stably outputting the current transmitted by the ACDC constant voltage module according to the signal transmitted by the analog and PWM dimming conversion module. According to the utility model, various fixed-point illumination settings with different maximum current brightness can be realized under the condition of one lamp, the production cost is effectively reduced, and the dimming effect is good.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, in particular to an LED dimming drive circuit. Background Art

[0002] Conventional LED driver dimming control typically uses wired or wireless dimming control methods. In some designs, when the same lamp and driver are used for fixed-point lighting, different maximum brightness settings are required for different scene lighting. If scene brightness settings are performed solely using software, software errors require a complete reset, which is time-consuming. Furthermore, existing technologies require matching specific LED lamps for specific lighting applications, resulting in high production costs and a failure to fully meet user needs.

[0003] Therefore, it is urgent to provide an LED dimming driving circuit to overcome the above-mentioned defects. Utility Model Content

[0004] The main purpose of the utility model is to provide an LED dimming drive circuit, which can realize a variety of fixed-point lighting settings with different maximum current brightness in the case of a lamp, effectively reduce production costs, and has the characteristics of good dimming effect.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] An LED dimming drive circuit, comprising:

[0007] ACDC constant voltage module, connected to the mains, converts high-voltage AC voltage into a constant low-voltage DC voltage;

[0008] A step-down and voltage-stabilizing power supply module that steps down and stabilizes the voltage transmitted by the ACDC constant voltage module to 5V / 3.3V output;

[0009] A Bluetooth module, connected to the step-down and voltage-stabilized power supply module, and configured to generate corresponding instruction instructions based on information received from the Bluetooth signal;

[0010] The MCU dimming control module is connected to the step-down and voltage-stabilized power supply module and is used to mix the Bluetooth dimming control signal and the knob dimming control signal and output two PWM1 and PWM2 dimming signals with a total of 100%;

[0011] Analog and PWM dimming conversion module, used to dim the LED using analog voltage or PWM when it is high or low brightness;

[0012] The DCDC constant current module stably outputs the current transmitted by the ACDC constant voltage module according to the signal transmitted by the analog and PWM dimming conversion module.

[0013] Preferably, the MCU dimming control module includes:

[0014] Knob input unit, used for users to input knob signals;

[0015] The MCU dimming processor is connected to the Bluetooth module and the knob input unit respectively, and mixes the signals transmitted by the two and outputs PWM1 and PWM2 dimming signals with a total of 100% respectively.

[0016] Preferably, the output range of the PWM1 dimming signal is a 20%-100% dimming signal, and the output range of the PWM2 dimming signal is a 1-20% reverse dimming signal.

[0017] Preferably, the MCU dimming processor includes a ME32G030AF8P6 chip, the Bluetooth control module is connected to pins 19 / 20 of the ME32G030AF8P6 chip, and the knob input unit is connected to pins 4 / 10 of the ME32G030AF8P6 chip.

[0018] Preferably, the knob input unit includes: an adjustable resistor VR1 connected to pin 10 of the ME32G030AF8P6 chip through a resistor R31, a capacitor C18 connected in parallel to the resistor R31 and the resistor R32 and connected to pin 10 of the ME32G030AF8P6 chip, the resistor R32 is connected to pin 4 of the ME32G030AF8P6 chip, and the other ends of the adjustable resistor VR1 and the capacitor C18 are both grounded.

[0019] Preferably, the analog and PWM dimming conversion module includes: a first conduction switch whose conduction is controlled by the PWM1 and PWM2 dimming signals, and a second conduction switch connected to the first conduction switch and correspondingly following the signal outputs of the PWM1 and PWM2 according to whether the first conduction switch is turned on or not.

[0020] Preferably, the first conduction switch is an NPN tube Q4, the PWM1 dimming signal is connected to the emitter of the NPN tube Q4 via the resistor R22, the PWM2 dimming signal is connected to the base and emitter of the NPN tube Q4 via the voltage divider resistor, and the collector of the NPN tube Q4 is connected to the second conduction switch.

[0021] Preferably, the voltage-dividing resistor includes a resistor R26 and a resistor R25 , wherein the resistor R26 is connected to the base of the NPN transistor Q4 and is connected to the emitter of the NPN transistor Q4 via the resistor R25 .

[0022] Preferably, the second switch is a PNP tube Q3, the base of the PNP tube Q3 is connected to the collector of the NPN tube Q4, the collector of the PNP tube Q3 is connected to a 5V voltage, and the emitter is output to the DCDC constant current module through a resistor R28.

[0023] Preferably, the DCDC constant current module includes: a constant current driver, and a plurality of LED lamps connected to the constant current driver; the DIM pin of the constant current driver is connected to the analog and PWM dimming conversion module.

[0024] The utility model discloses an LED dimming drive circuit. A step-down and voltage-stabilized power supply module stably outputs 3.3V and 5V to the Bluetooth module and the MCU dimming control module for power supply. The MCU dimming control module mixes the Bluetooth dimming control signal and the knob dimming control signal and then outputs a PWM1 dimming signal and a PWM2 dimming signal. This circuit can use analog voltage dimming when the LED is bright, making the dimming process smoother; and use PWM dimming when the LED is dimmed to achieve higher dimming accuracy. This allows a variety of fixed-point lighting settings with different maximum current brightness to be achieved with one lamp, effectively reducing production costs and having the characteristic of good dimming effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a module block diagram of an LED dimming drive circuit of the present utility model.

[0026] Figure 2 Schematic diagram of the circuit of the ACDC constant voltage module in this embodiment.

[0027] Figure 2a for Figure 2 An enlarged schematic diagram of the middle part of the circuit diagram.

[0028] Figure 2b for Figure 2 An enlarged schematic diagram of another part of the circuit diagram.

[0029] Figure 3 This is a circuit diagram of the step-down and voltage-stabilized power supply module of this embodiment.

[0030] Figure 4 FIG. 4 is a circuit diagram of the Bluetooth module of this embodiment.

[0031] Figure 5 FIG. 4 is a circuit diagram of the MCU dimming control module of this embodiment.

[0032] Figure 6 FIG. 4 is a circuit diagram of the analog and PWM dimming conversion module of this embodiment.

[0033] Figure 7 FIG. 4 is a circuit diagram of the DCDC constant current module of this embodiment.

[0034] Description of the figure numbers in the manual:

[0035] 1-ACDC constant voltage module, 2-buck voltage regulated power supply module, 3-Bluetooth module, 4-MCU dimming control module, 5-analog and PWM dimming conversion module, 6-DCDC constant current module. DETAILED DESCRIPTION

[0036] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0037] It should be noted that when an element is referred to as being “connected to” or “disposed on” another element, it can be directly on the other element or indirectly on the other element.

[0038] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0040] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0041] See Figure 1The LED dimming drive circuit of this embodiment includes: an ACDC constant voltage module 1, a step-down and voltage-stabilized power supply module 2, a Bluetooth module 3, an MCU dimming control module 4, an analog and PWM dimming conversion module 5, and a DCDC constant current module 6. The ACDC constant voltage module 1 is connected to the mains and converts the high-voltage AC voltage into a constant DC low voltage. The step-down and voltage-stabilized power supply module 2 steps down and stabilizes the voltage transmitted by the ACDC constant voltage module 1 to 5V / 3.3V output. The Bluetooth module 3 is connected to the step-down and voltage-stabilized power supply module 2 and is used to receive a signal based on the Bluetooth signal. The MCU dimming control module 4 is connected to the step-down and voltage-stabilized power supply module 2 and is used to mix the Bluetooth dimming control signal and the knob dimming control signal and output two PWM1 and PWM2 dimming signals with a total of 100%. The analog and PWM dimming conversion module 5 is used to dim the LED using analog voltage or PWM accordingly when the LED is high or low. The DCDC constant current module 6 stably outputs the current transmitted by the ACDC constant voltage module 1 according to the signal transmitted by the analog and PWM dimming conversion module 5.

[0042] Please combine Figure 2 、 Figure 2a and Figure 2b The ACDC constant voltage module 1 rectifies the high-voltage AC voltage into a unidirectional high-voltage DC voltage after passing through the EMC circuit and inputting into BD1. This pulse signal drives the constant voltage controller U2 (IW3627). The signal is then converted into a low-voltage DC voltage through MOS transistor Q2, transformer T1, output rectifier diode D2, output filter capacitor EC2, and other components to power the subsequent circuits. Since the ACDC constant voltage module 1 utilizes existing technology, it will not be described in detail here.

[0043] Please combine Figure 3 The step-down and voltage-stabilizing power supply module 2 converts the voltage transmitted by the ACDC constant voltage module 1 into a step-down and constant voltage unit through the DCDC switch chip U5 (XL7005A), the inductor L4 and the diode D6, and reduces and stabilizes the voltage to 5V to power the MCU dimming control module 4 and the analog and PWM dimming conversion module 5. The 5V voltage is then stepped down to 3.3V by the LDO circuit to power the Bluetooth module 3.

[0044] Please combine Figure 4 The Bluetooth control circuit of the Bluetooth module 3 receives the wireless dimming signal through Bluetooth, and the dimming signal is then transmitted from the TX pin end and RX pin end of the Bluetooth in combination with the TX and RX pins of the 5MCU dimming control module 4.

[0045] Combine Figure 5The MCU dimming control module 4 includes: a knob input unit for the user to input a knob signal, an MCU dimming processor connected to the Bluetooth module 3 and the knob input unit respectively, and mixing the signals transmitted by the two and outputting PWM1 and PWM2 dimming signals with a total of 100% respectively. Specifically, the output range of the PWM1 dimming signal is a 20%-100% dimming signal, the output range of the PWM2 dimming signal is a 1-20% reverse dimming signal, the MCU dimming processor includes a ME32G030AF8P6 chip, the Bluetooth control module 3 is connected to the 19 / 20 pins of the ME32G030AF8P6 chip, the knob input unit is connected to the 4 / 10 pins of the ME32G030AF8P6 chip, and the knob input unit includes: an adjustable resistor VR1 connected to pin 10 of the ME32G030AF8P6 chip through a resistor R31, a capacitor C18 connected in parallel to the resistor R31 and the resistor R32 and connected to pin 10 of the ME32G030AF8P6 chip, the resistor R32 is connected to pin 4 of the ME32G030AF8P6 chip, and the other ends of the adjustable resistor VR1 and the capacitor C18 are both grounded. More specifically, the MCU dimming control module 4 mixes the dimming signal sent by the Bluetooth module 3 and the AD sampling dimming signal of the adjustable resistor VR1 controlled by the knob, and outputs a 20-100% PWM dimming signal in PWM1 and a 0-20% inverted PWM dimming signal in PWM2. When the PWM1 dimming signal is ≥20%, PWM2 outputs a 0% dimming signal; when the PWM1 dimming signal is 20%, PWM1 outputs a 0-20% inverted dimming PWM signal.

[0046] Combine Figure 6The analog and PWM dimming conversion module 5 includes: a first conduction switch whose conduction is controlled by the PWM1 and PWM2 dimming signals, and a second conduction switch connected to the first conduction switch and correspondingly following the PWM1 and PWM2 signal outputs according to whether the first conduction switch is on or off. The first conduction switch is an NPN transistor Q4. The PWM1 dimming signal is connected to the emitter of the NPN transistor Q4 via a resistor R22. The PWM2 dimming signal is connected to the base and emitter of the NPN transistor Q4 via a voltage divider resistor. The collector of the NPN transistor Q4 is connected to the second conduction switch. The second switch is a PNP transistor Q3. The base of the PNP transistor Q3 is connected to the collector of the NPN transistor Q4. The collector of the PNP transistor Q3 is connected to a 5V voltage, and the emitter is output to the DCDC constant current module 6 through a resistor R28. Specifically, the PWM dimming signal output by PWM1 is converted into an analog DC voltage signal after integration and filtering by R22 and C12 and added to the emitter of PNP tube Q4. Since the PWM dimming signal output by PWM2 is 0% when the PWM dimming signal of PWM1 is ≥20%, the resistor R26 connected to the base of PNP tube Q4 is pulled low by PWM2, and R25 and R26 are the base voltage divider resistors of PNP tube Q4. By selecting appropriate voltage divider resistors R25 and R26, the base voltage of PNP tube Q4 after voltage division is always lower than the emitter voltage by 0.7V. PNP tube Q4 is forward-biased and the conduction voltage is applied to the base of NPN tube Q3. Since NPN tube Q3 is emitter output, its output voltage is controlled by the base voltage. Therefore, the base voltage of NPN tube Q3 determines the emitter output voltage of NPN tube Q3, and the emitter output voltage of NPN tube Q3 is then used to The IC dimming pin in the DCDC constant current module 6 is controlled to perform analog voltage dimming. When the PWM dimming signal of PWM1 is fixed at a minimum of 20%, the PWM2 dimming mode is entered. The PWM dimming signal output by PWM2 is 5V when the high level is high. At this time, when the PWM1 dimming signal is at a minimum of 20%, the voltage is 5*20%, which is about 1V. At this time, the base voltage of the PNP tube Q4 is 5V greater than the emitter voltage, causing the PNP tube Q4 to be reverse biased and not conducting. Conversely, it is forward biased and conducting at a low level, so that the signal at the base of the NPN tube Q3 becomes the PWM dimming signal of the controlled PWM2. The emitter output of the NPN tube Q3 follows the base and becomes the PWM signal output. The IC dimming pin in the DCDC constant current module 6 becomes PWM voltage dimming, so that the circuit can use analog voltage dimming when the LED is high brightness, making the dimming process smoother; and use PWM dimming when the LED is low brightness to achieve higher dimming accuracy.

[0047] Please combine Figure 7The DCDC constant current module 6 includes a constant current driver and several LED lamps connected to the constant current driver. The DIM pin of the constant current driver is connected to the analog and PWM dimming conversion module 5. Specifically, the constant current driver includes a PT4123E chip, whose SW pin is connected to the parallel electrolytic capacitor EC1 and resistor R8 via inductor L3. Resistor R8, the parallel electrolytic capacitor EC1 and resistor R8, are then connected to the series-connected LED lamps. The analog voltage / PWM voltage output by the analog and PWM dimming conversion module 5 is used to dim the LED lamps via the constant current driver.

[0048] The working principle of the present utility model is as follows: the AC power is converted into a DC voltage by the ACDC constant voltage module 1, the step-down and voltage-stabilized power supply module 2 steps down and stabilizes the voltage transmitted by the ACDC constant voltage module 1 to 5V / 3.3V output, and respectively powers the analog and PWM dimming conversion module 5, the MCU dimming control module 4 and the Bluetooth module 3. The MCU dimming control module 4 mixes the dimming signal sent by the Bluetooth module 3 and the AD sampling dimming signal of the adjustable resistor VR1 controlled by the knob, and outputs a 20-100% PWM dimming signal in PWM1 and a 0-20% inverted PWM dimming signal in PWM2. The analog and PWM dimming conversion module 5 controls the LED to high or low brightness through PWM1 and PWM2, and correspondingly uses analog voltage or PWM to control the dimming of the DCDC constant current module 6, so that the dimming process of the circuit is smoother and the dimming accuracy is higher.

[0049] From the above description, it can be seen that the utility model can realize multiple fixed-point lighting settings of different maximum current brightness in the case of a lamp, effectively reducing production costs and having the characteristic of good dimming effect.

[0050] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.

Claims

1. An LED dimming drive circuit, characterized in that: include: ACDC constant voltage module, connected to the mains, converts high-voltage AC voltage into constant low-voltage DC; A step-down and voltage-stabilizing power supply module, which steps down and stabilizes the voltage transmitted by the ACDC constant voltage module to 5V / 3.3V output; A Bluetooth module, connected to the step-down and voltage-stabilizing power supply module, and used to generate corresponding instruction instructions according to the information received by the Bluetooth signal; The MCU dimming control module is connected to the step-down and voltage-stabilized power supply module and is used to mix the Bluetooth dimming control signal and the knob dimming control signal and then output two-way PWM1 and PWM2 dimming signals whose sum is 100%; Analog and PWM dimming conversion module, used to dim the LED with analog voltage or PWM when it is high or low brightness; The DCDC constant current module stably outputs the current transmitted by the ACDC constant voltage module according to the signal transmitted by the analog and PWM dimming conversion module.

2. The LED dimming driving circuit according to claim 1, characterized in that: The MCU dimming control module includes: A knob input unit, used for the user to input a knob signal; The MCU dimming processor is connected to the Bluetooth module and the knob input unit respectively, and after mixing the signals transmitted by the two, outputs PWM1 and PWM2 dimming signals with a total of 100% respectively.

3. The LED dimming drive circuit according to claim 1 or 2, characterized in that: The output range of the PWM1 dimming signal is a 20%-100% dimming signal, and the output range of the PWM2 dimming signal is a 1-20% reverse dimming signal.

4. The LED dimming driving circuit according to claim 2, characterized in that: The MCU dimming processor includes a ME32G030AF8P6 chip, the Bluetooth control module is connected to pins 19 / 20 of the ME32G030AF8P6 chip, and the knob input unit is connected to pins 4 / 10 of the ME32G030AF8P6 chip.

5. The LED dimming drive circuit according to claim 2 or 4, characterized in that: The knob input unit includes: an adjustable resistor VR1 connected to pin No. 10 of the ME32G030AF8P6 chip through a resistor R31, a capacitor C18 connected in parallel with the resistor R31 and the resistor R32 and connected to pin No. 10 of the ME32G030AF8P6 chip, the resistor R32 is connected to pin No. 4 of the ME32G030AF8P6 chip, and the other ends of the adjustable resistor VR1 and the capacitor C18 are grounded.

6. The LED dimming driving circuit according to claim 1, characterized in that: The analog and PWM dimming conversion module includes: a first conduction switch controlled by the PWM1 and PWM2 dimming signals, and a second conduction switch connected to the first conduction switch and correspondingly following the signal outputs of the PWM1 and PWM2 according to whether the first conduction switch is turned on or off.

7. The LED dimming driving circuit according to claim 6, characterized in that: The first conduction switch is NPN tube Q4, the PWM1 dimming signal is connected to the emitter of NPN tube Q4 via resistor R22, the PWM2 dimming signal is connected to the base and emitter of NPN tube Q4 via a voltage divider resistor, and the collector of NPN tube Q4 is connected to the second conduction switch.

8. The LED dimming driving circuit according to claim 7, characterized in that: The voltage-dividing resistor includes a resistor R26 and a resistor R25 . The resistor R26 is connected to the base of the NPN transistor Q4 , and is connected to the emitter of the NPN transistor Q4 via the resistor R25 .

9. The LED dimming driving circuit according to claim 7 or 8, characterized in that: The second switch is a PNP tube Q3, the base of the PNP tube Q3 is connected to the collector of the NPN tube Q4, the collector of the PNP tube Q3 is connected to a 5V voltage, and the emitter is output to the DCDC constant current module through a resistor R28.

10. The LED dimming driving circuit according to claim 1, characterized in that: The DCDC constant current module includes: a constant current driver, and a plurality of LED lamps connected to the constant current driver; the DIM pin of the constant current driver is connected to the analog and PWM dimming conversion module.

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