Three-phase linear direct-drive dimming and toning circuit

Abstract

The invention discloses a three-phase linear direct-drive dimming and toning circuit, and the circuit comprises a three-phase silicon controlled rectifier dimming and toning module which adjusts an output voltage phase angle and generates a mode switching signal through a phase angle control unit and a mode switching unit respectively; the rectifier module converts alternating current into pulsating direct current; the dimming and color modulation control module is used for generating two paths of synchronous PWM (Pulse Width Modulation) signals and realizing light mode switching by detecting waveform and phase information of pulsating direct current; the linear constant current direct drive circuit drives the cold light LED and the warm light LED to achieve light mixing and color modulation according to the two paths of PWM signals. Through a three-phase direct drive architecture and a linear constant current technology, the technical problems of serious frequency flash, high electromagnetic interference, low three-phase compatibility and short service life in a traditional scheme are solved.

Description

Technical Field

[0001] This invention relates to the field of LED lighting technology, and in particular to a three-phase linear direct-drive dimming and color-tuning circuit. Background Technology

[0002] LEDs, as a new generation of green lighting source, have become the mainstream lighting technology due to their high efficiency, energy saving, long lifespan, and environmental friendliness. However, their current-driven characteristics require dedicated driver circuits to provide precise constant current control. Among the current mainstream driver technologies, switching solutions, while highly efficient, suffer from complex circuitry, high electromagnetic interference, and low reliability. Linear solutions, with their simple structure, face issues of low efficiency, poor power factor, and severe flicker. Traditional single-phase driver technology suffers from 100Hz rectification pulsation, resulting in flicker that is imperceptible to the human eye but harmful to health. Furthermore, the reliance on large-capacity electrolytic capacitors for filtering limits the system lifespan to several thousand hours, far below the 50,000-hour lifespan of LED light sources. Existing lightning protection designs generally use single-stage varistors or gas discharge tubes, which have slow lightning strike response speeds and insufficient residual voltage suppression capabilities, easily leading to damage to downstream driver circuits. While three-phase driver technology offers advantages in power density, existing solutions are still hampered by the high cost and low reliability resulting from the complex three-phase PFC rectification and DC-DC conversion structure, as well as the complex constant power control algorithms in linear solutions. With the development of modern lighting technology, users have an increasingly urgent need for dimming and color adjustment, as well as energy consumption optimization. However, existing technologies, due to poor electromagnetic compatibility, high-frequency switching noise interference, and high costs, are unable to meet the comprehensive requirements of modern lighting systems for flicker-free operation, long lifespan, and high reliability. Therefore, there is an urgent need for a three-phase linear direct-drive dimming and color adjustment circuit that features flicker-free output, low electromagnetic interference, high three-phase compatibility, and long lifespan. Summary of the Invention

[0003] The main objective of this invention is to propose a three-phase linear direct-drive dimming and color-tuning circuit, which aims to solve the technical problems of severe flicker, high electromagnetic interference, low three-phase compatibility, and short lifespan of existing LED three-phase drive circuits.

[0004] To achieve the above objectives, this invention proposes a three-phase linear direct-drive dimming and color-tuning circuit, comprising a three-phase thyristor dimming and color-tuning module, a rectifier module, a dimming and color-tuning control module, and a linear constant current direct-drive circuit. The input terminal of the three-phase thyristor dimming and color-tuning module is connected to three-phase AC power, and includes a phase angle control unit and a mode switching unit. The phase angle control unit is used to adjust the phase angle of the output AC voltage, and the mode switching unit sends a mode switching signal by adjusting the waveform of the output AC voltage. The input terminal of the rectifier module is connected to the output terminal of the three-phase thyristor dimming and color-tuning module, used to convert AC power into pulsating DC power. The dimming and color-tuning control module includes a dimming and color-tuning control chip; the dimming and color-tuning control chip has a first input... The input terminal is connected to the output terminal of the rectifier module to obtain the voltage waveform and phase information of the pulsating DC power. Based on the phase information, two phase-synchronized PWM dimming signals are generated, and when the mode switching signal is detected in the voltage waveform, the dimming mode and color mode are switched. The first input terminal of the linear constant current direct drive circuit is connected to the output terminal of the rectifier module, and the second input terminal is connected to the first output terminal of the dimming and color tuning control chip. Based on the first PWM signal, the cold light LED is driven with constant current and the brightness of the cold light is adjusted. The third input terminal is connected to the second output terminal of the dimming and color tuning control chip. Based on the second PWM signal, the warm light LED is driven with constant current and the brightness of the warm light is adjusted. The target color temperature is generated by mixing the cold light and the warm light.

[0005] Preferably, the rectifier module includes a first three-phase full-bridge rectifier circuit, a second three-phase full-bridge rectifier circuit, a bleeder circuit, and a phase sampling filter circuit; the input terminals of the first three-phase full-bridge rectifier circuit and the second three-phase full-bridge rectifier circuit are respectively connected to the output terminals of the three-phase thyristor dimming and color-tuning module; the output terminal of the first three-phase full-bridge rectifier circuit is connected to the input terminal of the bleeder circuit, the output terminal of the bleeder circuit is connected to the input terminal of the phase sampling filter circuit, and the output terminal of the phase sampling filter circuit is connected to the first input terminal of the dimming and color-tuning control chip; the output terminal of the second three-phase full-bridge rectifier circuit is connected to the first input terminal of the linear constant current direct drive circuit.

[0006] Preferably, the bleeder circuit includes a Zener diode, a transistor, a power switch, a first voltage divider network, and a bleeder network; the input terminal of the first voltage divider network is connected to the output terminal of the first three-phase full-bridge rectifier circuit, the first output terminal is connected to the cathode of the Zener diode, and the second output terminal is connected to the drain of the power switch; the anode of the Zener diode is connected to the base of the transistor, the collector of the transistor is connected to the gate of the power switch, and the emitter of the transistor is grounded; the source of the power switch is grounded through the bleeder network; when the output voltage of the first three-phase full-bridge rectifier circuit exceeds a set threshold, the Zener diode breaks down and conducts, triggering the transistor to conduct, thereby driving the power switch to open the bleeder path.

[0007] Preferably, the discharge circuit further includes a first diode, a first resistor, a first capacitor, and a second capacitor; the cathode of the first diode is connected to the base of the transistor, and the anode is connected to the source of the power switch; the first resistor and the first capacitor are connected in parallel between the base and emitter of the transistor; the second capacitor is connected across the source of the power switch and ground.

[0008] Preferably, the phase sampling filter circuit includes a second voltage divider resistor network, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a second resistor, and a third resistor; the input terminal of the second voltage divider resistor network is connected to the output terminal of the bleeder circuit, and the output terminal is connected to the first terminal of the third capacitor, the first terminal of the fourth capacitor, and the first terminal of the second resistor; the second terminal of the second resistor is connected to the first terminal of the fifth capacitor and the first terminal of the third resistor, and the second terminal of the third resistor and the first terminal of the sixth capacitor are both connected to the first input terminal of the dimming and color tuning control chip; the ground terminal of the second voltage divider resistor network, the second terminal of the third capacitor, the second terminal of the fourth capacitor, the second terminal of the fifth capacitor, and the second terminal of the sixth capacitor are all grounded.

[0009] Preferably, the circuit further includes a constant voltage circuit, which comprises a constant voltage driver chip, a power inductor, a second diode, a third diode, a seventh capacitor, an eighth capacitor, and a ninth capacitor. The first input terminal of the constant voltage driver chip and the first terminal of the seventh capacitor are connected to the output terminal of the second three-phase full-bridge rectifier circuit, and the second input terminal is connected to the cathode of the second diode and the first terminal of the eighth capacitor. The ground terminal of the constant voltage driver chip is connected to the second terminal of the eighth capacitor, the first terminal of the power inductor, and the cathode of the third diode. The anode of the second diode is connected to the first terminal of the ninth capacitor and the second terminal of the power inductor, serving as the positive terminal of the constant voltage circuit output. The second terminal of the seventh capacitor, the anode of the third diode, and the second terminal of the ninth capacitor are grounded.

[0010] Preferably, the linear constant current direct drive circuit includes a first linear constant current direct drive chip and a second linear constant current direct drive chip; the first input terminal of the first linear constant current direct drive chip is connected to the output terminal of the rectifier module, and the second input terminal is connected to the first output terminal of the dimming and color-tuning control chip, driving the cold light LED with constant current based on the first PWM signal and adjusting its brightness; the first input terminal of the second linear constant current direct drive chip is connected to the output terminal of the rectifier module, and the second input terminal is connected to the second output terminal of the dimming and color-tuning control chip, driving the warm light LED with constant current based on the second PWM signal and adjusting its brightness, thereby achieving target color temperature adjustment through the mixing of cold and warm light.

[0011] Preferably, the dimming and color-tuning control module further includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a tenth capacitor, and an eleventh capacitor; the first output terminal of the dimming and color-tuning control chip is connected to the first terminal of the fourth resistor, and the second terminal of the fourth resistor, the first terminal of the fifth resistor, and the first terminal of the tenth capacitor are all connected to the second input terminal of the linear constant current direct drive circuit; the second output terminal of the dimming and color-tuning control chip is connected to the first terminal of the sixth resistor, and the second terminal of the sixth resistor, the first terminal of the seventh resistor, and the first terminal of the eleventh capacitor are all connected to the third input terminal of the linear constant current direct drive circuit; the second terminals of the fifth resistor, the seventh resistor, the tenth capacitor, and the eleventh capacitor are all grounded.

[0012] Preferably, the three-phase thyristor dimming module includes three identical three-phase dimming circuits, corresponding to the LA, LB, and LC phase inputs respectively; each phase dimming circuit includes a bidirectional thyristor, a bidirectional trigger diode, an adjustable resistor, and a buffer absorption network; the first control electrode of the bidirectional thyristor is connected to the first terminal of the adjustable resistor and the phase line input terminal, the gate of the bidirectional thyristor is connected to the first terminal of the bidirectional trigger diode, and the second terminal of the adjustable resistor is connected to the second terminal of the bidirectional trigger diode; the buffer absorption network is connected in parallel between the first and second control electrodes of the bidirectional thyristor.

[0013] Preferably, the system further includes a three-phase lightning protection module, which comprises a primary lightning protection circuit, a secondary lightning protection circuit, and a tertiary lightning protection circuit. The primary lightning protection circuit includes a varistor and a gas discharge tube connected in series between each pair of phase lines, and a varistor and a gas discharge tube connected in series between each phase line and ground, for discharging common-mode and differential-mode surge energy. The input terminal of the secondary lightning protection circuit is connected to the output terminal of the primary lightning protection circuit, and includes an inductor and a gas discharge tube connected in parallel in each phase line, a transient voltage suppression diode connected between each pair of phase lines, and a transient voltage suppression diode and a gas discharge tube connected in series between each phase line and ground, for further clamping transient overvoltages. The input terminal of the tertiary lightning protection circuit is connected to the output terminal of the secondary lightning protection circuit, and includes a capacitor connected between each pair of phase lines and a capacitor connected between each phase line and ground, for absorbing residual surge energy and suppressing high-frequency interference.

[0014] This invention proposes a three-phase linear direct-drive dimming and color-tuning circuit. By using a three-phase rectified direct-drive output of high-frequency pulsating DC power, it completely eliminates the flickering phenomenon of traditional single-phase circuits, solving the problems of visual fatigue and camera flicker interference. Through a linear constant-current drive circuit with no electrolytic capacitors, it avoids the short lifespan of traditional drive circuits, significantly improving the lifespan of the drive circuit. Using dual-channel phase-synchronous PWM control technology, combined with cold / warm light constant-current drive, it achieves high-precision stepless mixing and adjustment of brightness and color temperature. The three-phase rectified direct-drive architecture eliminates the traditional switching power supply conversion stage, improving system efficiency. Integrated control via a dimming and color-tuning integrated chip simplifies the circuit structure, reduces electromagnetic interference, and improves electromagnetic compatibility and cost advantages.

[0015] Furthermore, this invention also employs a physical isolation design of dual three-phase full-bridge rectifier circuits to prevent power loop noise from coupling to the control chip, thereby improving the sampling accuracy and anti-interference capability of the control signal and enhancing system stability; a dedicated phase detection circuit in the first rectifier circuit improves zero-crossing positioning accuracy; an independent drive of the cold / warm LEDs in the second rectifier circuit improves power transmission efficiency and reduces crosstalk distortion; dynamic clamping of overvoltage spikes in the bleeder circuit improves the stability of the phase sampling signal; a composite filter network filters out high-frequency interference, improving zero-crossing detection accuracy; and coordinated bleedering and filtering enhance the anti-interference capability of the control chip. The overvoltage protection system employs a Zener diode for precise threshold triggering, improving overvoltage protection response speed; a cascaded power switch structure driven by a transistor enhances the reliability of the discharge path; efficient energy dissipation through a discharge resistor network improves voltage clamping stability and system safety; reverse blocking design of the first diode enhances the transistor's base anti-interference capability; a parallel RC network at the base suppresses the risk of high-frequency false triggering; a source-connected capacitor absorbs transient spikes from the switch, reducing voltage stress on the power transistor; multi-stage collaborative protection improves discharge stability and system reliability; and a voltage divider resistor network provides network voltage reduction, improving high-voltage signal acquisition. Safety features include: improved anti-interference capability across the entire frequency band through multi-capacitor parallel wideband filtering; improved phase signal extraction accuracy through dual-stage RC low-pass filtering; efficient conversion of pulsating DC to stable low-voltage DC through a constant voltage circuit, improving power supply stability for the control chip and color adjustment module; enhanced energy transfer continuity through the synergistic effect of power inductor magnetic energy conversion and freewheeling diodes; improved PWM signal anti-interference through an RC filter network composed of the fifth and seventh resistors and the tenth and eleventh capacitors; improved accuracy and flexibility of color temperature adjustment through independent driving of cold and warm LEDs by two PWM signals; and improved linear constant current control. Improve brightness stability and LED lifespan; enhance the consistency of brightness adjustment accuracy between cold and warm light through a dual-channel independent filtering architecture; improve grid load balance and phase control consistency through a three-phase independent symmetrical topology design; achieve conduction angle accuracy through coordinated adjustment of adjustable resistors and bidirectional trigger diodes; improve thyristor lifespan by suppressing commutation overvoltage and turn-off spikes through a buffer absorption network; improve system reliability and stability in harsh grid environments by discharging and absorbing surge energy through a multi-level lightning protection design; and improve circuit anti-interference capability and lifespan by suppressing high-frequency interference and clamping transient overvoltages.

[0016] In summary, this invention solves the technical problems of severe flicker, high electromagnetic interference, low three-phase compatibility, and short lifespan of existing LED three-phase driving circuits. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 A circuit principle block diagram of a three-phase linear direct-drive dimming and color-tuning circuit provided in an embodiment of the present invention; Figure 2 A circuit principle block diagram of another three-phase linear direct-drive dimming and color-tuning circuit provided in an embodiment of the present invention; Figure 3 A circuit diagram of a three-phase thyristor dimming and color-tuning module provided in an embodiment of the present invention; Figure 4 A circuit diagram of a second three-phase full-bridge rectifier circuit and a linear constant current direct drive circuit provided in an embodiment of the present invention; Figure 5 A circuit diagram of a first three-phase full-bridge rectifier circuit, a bleeder circuit, and a phase sampling filter circuit provided in an embodiment of the present invention; Figure 6 A circuit diagram of a constant voltage circuit provided in an embodiment of the present invention; Figure 7 The circuit diagram of a dimming and color-tuning control module provided in an embodiment of the present invention; Figure 8 The circuit diagram of a three-phase lightning protection module provided in an embodiment of the present invention is shown.

[0019] In the attached diagram: 1-Three-phase thyristor dimming and color-tuning module, 2-Rectifier module, 21-First three-phase full-bridge rectifier circuit, 22-Second three-phase full-bridge rectifier circuit, 3-Dimming and color-tuning control module, 4-Linear constant current direct drive circuit, 5-Discharge circuit, 6-Phase sampling filter circuit, 7-Constant voltage circuit, 8-Three-phase lightning protection module, 9-Induction module.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that if the embodiments of the present invention involve directional indicators, such as up, down, left, right, front, back, etc., the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] The main objective of this invention is to propose a three-phase linear direct-drive dimming and color-tuning circuit, which aims to solve the technical problems of severe flicker, high electromagnetic interference, low three-phase compatibility, and short lifespan of existing LED three-phase drive circuits.

[0025] like Figures 1 to 7 As shown, this invention proposes a three-phase linear direct-drive dimming and color-tuning circuit, including a three-phase thyristor dimming and color-tuning module 1, a rectifier module 2, a dimming and color-tuning control module 3, and a linear constant current direct-drive circuit 4. The input terminal of the three-phase thyristor dimming and color-tuning module 1 is connected to three-phase AC power, and includes a phase angle control unit and a mode switching unit. The phase angle control unit is used to adjust the phase angle of the output AC voltage, and the mode switching unit sends a mode switching signal by adjusting the waveform of the output AC voltage. The input terminal of the rectifier module 2 is connected to the output terminal of the three-phase thyristor dimming and color-tuning module 1, and is used to convert AC power into pulsating DC power. The dimming and color-tuning control module 3 includes a dimming and color-tuning control chip. The dimming and color-tuning control chip has a... One input terminal is connected to the output terminal of rectifier module 2 to acquire the voltage waveform and phase information of pulsating DC power. Based on the phase information, two phase-synchronized PWM dimming signals are generated, and the dimming mode and color mode are switched when a mode switching signal is detected in the voltage waveform. The first input terminal of the linear constant current direct drive circuit 4 is connected to the output terminal of rectifier module 2, and the second input terminal is connected to the first output terminal of the dimming and color control chip. Based on the first PWM signal, the cold light LED is driven by constant current and the brightness of the cold light is adjusted. The third input terminal is connected to the second output terminal of the dimming and color control chip. Based on the second PWM signal, the warm light LED is driven by constant current and the brightness of the warm light is adjusted. The target color temperature is generated by mixing cold light and warm light.

[0026] Specifically, in one embodiment of the present invention, the input terminal of the three-phase thyristor dimming and color-tuning module 1 is connected to three-phase AC power. The three-phase thyristor dimming and color-tuning module 1 includes a multi-function control button, which switches the dimming mode and color-tuning mode by axial pressing (mode switching unit), and adjusts the phase angle of the output AC voltage by rotation (phase angle control unit). After phase angle adjustment, a variable AC voltage is output to the rectifier module 2. The input terminal of the rectifier module 2 is connected to the output terminal of the three-phase thyristor dimming and color-tuning module 1. In this embodiment, the rectifier module 2 is a three-phase full-bridge topology, used to convert AC power into 300Hz pulsating DC power. The dimming and color-tuning control module 3 includes a dimming and color-tuning control chip U4, model MC32F7073. The first input terminal (pin 15) of the dimming and color-tuning control chip U4 is connected to the output terminal (VS1) of the rectifier module 2 to obtain the phase information and voltage waveform of the 300Hz pulsating DC power, and detects the zero-crossing point of the 300Hz pulsating waveform in real time. The light color adjustment control chip U4 generates two phase-synchronized PWM dimming signals based on the phase information of the pulsating DC current. At the same time, it monitors whether the voltage waveform matches the characteristics of the axial pressing action of the multi-function control button (such as a specific voltage dip in the pulsating waveform). If it matches, it triggers the switching between the dimming mode and the color adjustment mode. The linear constant current direct drive circuit 4 includes a linear constant current direct drive chip. The first input terminal of the linear constant current direct drive chip is connected to the output terminal of the rectifier module 2 through a voltage divider resistor network to obtain chip power. The second input terminal of the linear constant current direct drive chip is connected to the first output terminal (pin 7) of the dimming and color adjustment control chip U4. Based on the first PWM signal (PWM_C), it drives the cold light LED with constant current and adjusts the brightness of the cold light. The third input terminal of the linear constant current direct drive chip is connected to the second output terminal (pin 8) of the dimming and color adjustment control chip U4. Based on the second PWM signal (PWM_W), it drives the warm light LED with constant current and adjusts the brightness of the warm light. The target color temperature is generated by mixing the cold light and the warm light.

[0027] The specific working process is as follows: Three-phase AC power is input to the three-phase thyristor dimming and color-tuning module 1. When the user presses the multi-function control button axially, the thyristor is triggered to turn off momentarily, generating a specific voltage dip in the output waveform. When the user rotates the button, the three sets of adjustable resistors are adjusted synchronously through the mechanical linkage mechanism, changing the conduction angle of the bidirectional thyristor and thus changing the effective value of the output voltage to achieve basic brightness adjustment. The dimmed three-phase AC power is processed by the rectifier module 2, outputting 300Hz pulsating DC power to the first input terminal of the dimming and color-tuning control chip U4, which captures the zero-crossing point of the pulsating waveform in real time to generate a synchronous clock reference. When the dimming and color-tuning control chip U4 detects a specific voltage dip in the pulsating DC voltage waveform... When a certain voltage dip occurs, it is determined that the multi-function control button has been pressed, and the dimming / color adjustment mode is switched. In dimming mode, the dimming and color adjustment control chip U4 generates two strictly synchronized PWM signals (PWM_C and PWM_W) based on a phase reference. Their rising edges are precisely aligned with the zero-crossing point of the 300Hz pulsating waveform. At this time, rotating the button adjusts the duty cycle of PWM_C / PWM_W in the same direction (0-100%) to achieve stepless brightness adjustment. In color adjustment mode, rotating the button adjusts the duty cycle of PWM_C / PWM_W in the opposite direction (e.g., PWM_C:100%→0%, PWM_W:0%→100%) to achieve continuous color temperature adjustment. The linear constant current direct drive circuit 4 receives the PWM_C signal and the 300Hz pulsating DC power from the rectifier circuit, adjusting the current of the cool LED according to the PWM duty cycle within the pulsation period. The linear constant current direct drive circuit 4 also receives the PWM_W signal and the 300Hz pulsating DC power from the rectifier circuit, adjusting the current of the warm LED according to the PWM duty cycle within the pulsation period. The dual LED light outputs are spatially mixed to form the target color temperature. Because the drive current and supply voltage are strictly phase-synchronized, perceptible brightness fluctuations are completely eliminated, achieving flicker-free lighting. The entire process abandons traditional electrolytic capacitor filtering, directly utilizing the 300Hz high-frequency pulsation characteristics to suppress flicker. Simultaneously, the dual-rectifier physical isolation design ensures that phase detection is not affected by power fluctuations.

[0028] It should be noted that the 300Hz pulsating DC power in this embodiment is the typical output frequency under a 50Hz power grid. The actual circuit design has the ability to adapt to the power grid frequency: when applied to a 60Hz power grid (such as the US standard), the fundamental frequency of the rectifier module output automatically switches to 360Hz. The dimming and color adjustment control chip adjusts the phase detection algorithm in real time through the internal phase-locked loop (PLL) to ensure that the PWM signal is always accurately aligned with the zero-crossing point of the pulsating waveform during synchronous refresh. This adaptive mechanism makes the circuit compatible with global power grid standards (50Hz / 60Hz and others), maintaining flicker-free characteristics and color temperature adjustment accuracy. The core innovation lies in the "rectifier". The constant relationship of "frequency = 6 × grid frequency" and the chip's adaptive synchronous control architecture are not limited by specific frequency values. The rectifier module 2 can use a three-phase full-bridge circuit built with discrete diodes, or a half-bridge rectifier, integrated rectifier module, or other equivalent rectifier circuits. The core is to output pulsating DC power. The linear constant current direct drive circuits for cold and warm light are directly powered by pulsating DC power, abandoning the traditional electrolytic capacitor filtering design. The phase-synchronous PWM signal generated by the dimming and color-tuning control chip U4 precisely controls the LED current waveform, so that the driving current and the pulsating voltage are strictly aligned in phase, thereby achieving frequencyless flashing output and completely eliminating the lifespan bottleneck of electrolytic capacitors.

[0029] Understandably, this embodiment achieves dimming and color adjustment using a thyristor through the combination of a phase angle control unit and a mode switching unit; it completely eliminates the flickering phenomenon of single-phase drive circuits by combining high-frequency pulsed direct drive with dual-channel phase-synchronous PWM control; it effectively improves the lifespan of the drive circuit through an electrolytic capacitor-free design; it eliminates the traditional switching power supply conversion stage through a three-phase rectifier direct drive architecture, improving system efficiency; it achieves high-precision independent adjustment of cool / warm light brightness through phase synchronization technology, improving color temperature mixing uniformity; and it simplifies the circuit through an integrated control chip, improving electromagnetic compatibility and cost advantages.

[0030] Those skilled in the art can make corresponding equivalent improvements based on the application scenario. For example, the phase angle control unit can be replaced with a digital potentiometer solution to control the conduction angle of the thyristor via an external wireless signal; optocoupler isolation technology or a digital isolator can be used to electrically isolate the color tuning module from the control chip to prevent power stage noise from interfering with the control signal; or an ambient light sensor can be integrated into the color tuning module to achieve adaptive color temperature adjustment, dynamically adjusting the cool / warm light mixing ratio according to the ambient brightness; or a SiC Schottky diode can be used to replace the traditional silicon fast recovery diode to build a rectifier bridge, reducing conduction losses and improving conversion efficiency; or an ambient temperature sensor can be introduced to link the PWM duty cycle to achieve temperature-compensated automatic brightness adjustment; or an AI algorithm can be embedded in the dimming and color tuning control chip to automatically generate a color temperature curve based on user habits.

[0031] Preferred, see Figure 2 , Figure 4 and Figure 5 In a specific embodiment of the present invention, the rectifier module 2 includes a first three-phase full-bridge rectifier circuit 21, a second three-phase full-bridge rectifier circuit 22, a bleeder circuit 5, and a phase sampling filter circuit 6; the input terminals of the first three-phase full-bridge rectifier circuit 21 and the second three-phase full-bridge rectifier circuit 22 are respectively connected to the output terminals of the three-phase thyristor dimming and color-tuning module 1; the first three-phase full-bridge rectifier circuit 21 is composed of diodes D9, D2, D3, D4, D5, and D6. The output terminal of the first three-phase full-bridge rectifier circuit 21 is connected to the input terminal of the bleeder circuit 5. The output terminal of the bleeder circuit 5 is connected to the input terminal of the phase sampling filter circuit 6. The output terminal of the phase sampling filter circuit 6 is connected to the first input terminal 15 (VS1 signal) of the dimming and color tuning control chip U4. The second three-phase full-bridge rectifier circuit 22 is composed of diodes D11, D12, D13, D14, D15, and D16. The output terminal of the second three-phase full-bridge rectifier circuit 22 is connected to the first input terminal of the linear constant current direct drive circuit 4 to provide power. When the output voltage of the first three-phase full-bridge rectifier circuit 21 exceeds the set threshold, the Zener diode breaks down and conducts, triggering the transistor to conduct, thereby driving the power switch to open the bleeder path.

[0032] Understandably, this embodiment completely eliminates interference from the power circuit to the phase sampling signal through a dual independent rectifier circuit physical isolation design; improves the detection accuracy of the zero-crossing phase signal through a dedicated signal sampling and rectification channel; enhances the minimum load current maintenance capability under thyristor dimming conditions through a cascaded architecture of independent bleeder circuits and filter circuits; improves the anti-interference accuracy of zero-crossing detection through a dedicated rectification path for the phase sampling branch; avoids false triggering of the control chip caused by large current fluctuations through an independent signal sampling channel, reduces electromagnetic crosstalk, and improves system stability; and achieves fault isolation between the control and drive systems through a separate power supply architecture, improving overall reliability.

[0033] Those skilled in the art can make corresponding equivalent improvements based on the application scenario, such as replacing the discrete diode solution with an integrated dual-channel rectifier module; or using magnetic isolation technology to construct virtual electrical isolation and transmitting phase signals through an isolation amplifier.

[0034] Preferred, see Figure 5In a specific embodiment of the present invention, the bleeder circuit 5 includes a Zener diode D1, a transistor Q1, a power switch Q2, a first voltage divider resistor network, and a bleeder resistor network. In this embodiment, the power switch Q2 is an NMOS transistor. The input terminal of the first voltage divider resistor network is connected to the output terminal of the first three-phase full-bridge rectifier circuit 21, the first output terminal of the first voltage divider resistor network is connected to the cathode of the Zener diode D1, and the second output terminal of the first voltage divider resistor network is connected to the drain of the power switch Q2. The anode of the Zener diode D1 is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to the gate of the power switch Q2, and the emitter of the transistor Q1 is grounded. The source of the power switch Q2 is grounded through the bleeder resistor network. When the output voltage of the first three-phase full-bridge rectifier circuit 21 exceeds a set threshold, the Zener diode D1 breaks down and conducts, triggering the transistor Q1 to conduct, thereby driving the power switch Q2 to open the bleeder path. In this embodiment, the first voltage divider resistor network includes resistors R1, R3, R4, R5, R6, and R7; the bleeder resistor network includes resistors RS1 and RS2. Those skilled in the art can adjust the composition and resistance value of the resistor network according to actual needs. The specific working process is as follows: When the output voltage of the first three-phase full-bridge rectifier circuit 21 increases, the first voltage divider resistor network divides the high-voltage signal proportionally. If the voltage at the first output terminal reaches the breakdown threshold of the Zener diode D1, the Zener diode D1 breaks down and conducts in reverse, and current is injected into the base of transistor Q1 to saturate and conduct. The collector current of transistor Q1 drives the gate voltage of power switch Q2 to pull down, triggering power switch Q2 to conduct completely, forming a low-impedance discharge path. The rectified output current flows into the discharge resistor network through the drain-source channel of power switch Q2, converting electrical energy into heat energy for dissipation, forcing the rectified output voltage to be clamped at a safe value. When the voltage falls back below the threshold, the Zener diode D1 returns to the cutoff state. At this time, the base current of transistor Q1 is interrupted, resulting in an open collector. The gate potential of Q2 rises back to the cutoff region, the discharge path is automatically turned off, and the system returns to normal monitoring. The entire process is completed within 10 microseconds, achieving dynamic suppression of overvoltage conditions such as power grid surges and load mutations, and ensuring that the phase sampling signal is stable and distortion-free.

[0035] Understandably, this embodiment improves the overvoltage protection response speed through the precise threshold triggering mechanism of the Zener diode; improves the reliability of the discharge path control through the transistor-driven power switch conduction structure; improves the surge energy dissipation efficiency through the power conversion design of the discharge resistor network; improves the stability of the phase sampling signal through the dynamic voltage clamping function; and improves the system's continuous monitoring capability through the automatic shutdown and recovery mechanism.

[0036] Those skilled in the art can make corresponding equivalent improvements based on the application scenario, such as: replacing the Zener diode with a voltage comparator to achieve digital threshold setting; or using IGBT devices to replace NMOS transistors to adapt to high voltage and high current scenarios; or using positive temperature coefficient thermistors to replace the bleeder resistor network to achieve overcurrent self-protection; or adding RC delay circuits to optimize anti-interference performance; or introducing optocoupler isolation drive to enhance electrical safety.

[0037] Preferred, see Figure 5 In a specific embodiment of the present invention, the discharge circuit 5 further includes a first diode D10, a first resistor R2, a first capacitor C17, and a second capacitor C2. The cathode of the first diode D10 is connected to the base of transistor Q1, and the anode is connected to the source of power switch Q2, forming a reverse current blocking path. The first resistor R2 and the first capacitor C17 are connected in parallel between the base and emitter of transistor Q1 to form a high-frequency filter network, used to suppress false triggering caused by high-frequency interference. The second capacitor C2 is connected across the source of power switch Q2 and ground to absorb transient spikes during switching. When the discharge circuit is working, the first capacitor C2 filters out interference signals from the base of transistor Q1, the first diode D10 accelerates charge release during the turn-off period, and the second capacitor C2 suppresses source voltage oscillation of power switch Q2. The three components work together to improve discharge stability.

[0038] Understandably, this embodiment improves the anti-interference capability during the discharge turn-off period through diode reverse current blocking design; suppresses the risk of high-frequency false triggering through base RC filter network; reduces power transistor voltage stress through source transient absorption capacitor; and improves system reliability through multiple transient suppression synergy.

[0039] Those skilled in the art can make corresponding equivalent improvements based on the application scenario, such as: replacing the first diode D10 with a low-dropout Schottky diode to improve the reverse blocking speed; or using a TVS diode in parallel with C2 to enhance transient overvoltage absorption; or using an NTC thermistor in series with R2 to achieve temperature compensation; or adding a gate charge discharge circuit to optimize the turn-off characteristics of the power switch Q2.

[0040] Preferred, see Figure 5In a specific embodiment of the present invention, the phase sampling filter circuit 6 includes a second voltage divider resistor network, a third capacitor EC1, a fourth capacitor C3, a fifth capacitor C4, a sixth capacitor C5, a second resistor R11, and a third resistor R12. In this embodiment, the third capacitor EC1 is an electrolytic capacitor. The input terminal of the second voltage divider resistor network is connected to the output terminal of the bleeder circuit 5, and is used to safely divide the high-voltage signal output by the bleeder circuit to a low-voltage range. The high-voltage side resistor bears the main voltage drop, improving the withstand voltage safety. In this embodiment, the second voltage divider resistor network includes resistors R8, R15, R9, and R10. The output terminal of the second voltage divider resistor network is connected to the positive terminal of the third capacitor EC1 and the first terminal of the fourth capacitor C3. The first terminal of the second resistor R11 and the first terminal of the third capacitor EC1 are connected. The large capacitance of the third capacitor EC1 can effectively filter out low-frequency ripple interference below 100Hz. The high-frequency characteristics of the fourth capacitor C3 can suppress high-frequency noise generated by thyristor commutation. The two capacitors complement each other to improve the anti-interference capability of the whole band. The second terminal of the second resistor R11 is connected to the first terminal of the fifth capacitor C4 and the first terminal of the third resistor R12. The second terminal of the third resistor R12 and the first terminal of the sixth capacitor C5 are connected to the first input terminal 15 (VS1) of the dimming and color tuning control chip U4. The ground terminal of the second voltage divider resistor network, the negative terminal of the third capacitor EC1, the second terminal of the fourth capacitor C3, the second terminal of the fifth capacitor C4 and the second terminal of the sixth capacitor C5 are all grounded. At this point, the second resistor R11 and the fifth capacitor C4 form the first-stage RC low-pass filter, which is used to filter out the commutation spikes of the thyristor. Then, the second-stage RC filter, which is composed of the third resistor R12 and the sixth capacitor C5, further purifies the signal, and finally outputs a pure fundamental phase signal to the VS1 pin of U4. This effectively solves the problem of zero-crossing detection inaccuracy caused by high-frequency interference in the traditional solution, improves the uniformity of color temperature mixing, and eliminates PWM synchronization error.

[0041] Understandably, this embodiment uses high-voltage divider resistors to securely acquire signals and improve withstand voltage reliability; it uses electrolytic capacitor EC1 and capacitor C3 for wide-band complementary filtering to improve full-band anti-interference capability; it uses dual-stage RC low-pass filtering to improve the phase signal signal-to-noise ratio; and it uses precise extraction of the fundamental frequency to improve PWM synchronization accuracy.

[0042] Those skilled in the art can make corresponding equivalent improvements based on the application scenario, such as: replacing the electrolytic capacitor EC1 with a solid capacitor to improve the high-frequency response; or using a π-type LC filter to replace the RC structure to enhance out-of-band rejection; or using a switched capacitor filter to achieve dynamic adjustment of the cutoff frequency; or adding a digital isolator to build an electrical safety barrier.

[0043] Preferred, see Figure 6In a specific embodiment of the present invention, a constant voltage circuit 7 is further included. The constant voltage circuit 7 includes a constant voltage driver chip U3, a power inductor T1, a second diode D7, a third diode D8, a seventh capacitor EC2, an eighth capacitor C9, and a ninth capacitor EC3. The constant voltage driver chip U3 is a BP2525F, and the seventh capacitor EC2 and the ninth capacitor EC3 are electrolytic capacitors. The first input terminal DRAIN pin of the constant voltage driver chip U3 is connected to the output terminal of the second three-phase full-bridge rectifier circuit 22 through the positive terminal of the seventh capacitor EC2. The second input terminal VCC pin is connected to the cathode of the second diode D7 and the first terminal of the eighth capacitor C9. The ground terminal GND pin of the constant voltage driver chip U3 is connected to the second terminal of the eighth capacitor C9, the first terminal of the power inductor T1, and the cathode of the third diode D8. The anode of the second diode D8 is connected to the positive terminal of the ninth capacitor EC3 and the second terminal of the power inductor T1, serving as the positive terminal of the output terminal of the constant voltage circuit 7. The negative terminal of the seventh capacitor EC2, the anode of the third diode D8, and the negative terminal of the ninth capacitor EC3 are grounded.

[0044] The working process is as follows: When the second three-phase full-bridge rectifier circuit 22 outputs pulsating DC power, the constant voltage drive chip U3 starts high-frequency switching control through its internal oscillator: the input high voltage is filtered by the seventh capacitor EC2 to remove high-frequency noise and then connected to the first input terminal DRAIN pin of chip U3; the second input terminal VCC pin of chip U3 forms a stable power supply circuit through the second diode D7 and the eighth capacitor C9; the power inductor T1 is periodically turned on / off under the drive signal. During the on period, the current is transferred from the input terminal to the output terminal through the power inductor T1, supplying energy to the load and the ninth capacitor EC3. At the same time, the power inductor T1 stores energy, and the ninth capacitor EC3 and the resistor R26 form an output filter network to absorb ripple; during the off period, the power inductor T1 releases energy, and the current continues through the third diode D8 to maintain the continuous output current. The ninth capacitor EC3 continuously smooths the output voltage ripple, and the eighth capacitor C9 suppresses the VCC power supply fluctuation of chip U3; finally, the pulsating DC power is efficiently converted into stable low-voltage DC power, providing a clean power supply for the dimming and color-tuning control chip U4 and the color-tuning module 3. It should be noted that the CS pin of the constant voltage driver chip U3 is connected to the GND pin through resistor R24 ​​for real-time detection of the peak current of the power inductor, realizing cycle-by-cycle overcurrent protection. When the current exceeds the set threshold, the internal MOSFET is immediately turned off to prevent inductor saturation damage. Resistor R24 ​​is used to detect the peak current of the power inductor in real time to realize overcurrent protection. The SEL pin of the constant voltage driver chip U3 is connected to the third resistor voltage divider network, which in this embodiment is resistor R20 and resistor R23, used to set the output voltage value of the constant voltage driver chip U3. The output DC voltage is precisely controlled by adjusting the voltage division ratio. Those skilled in the art can set it according to actual needs.

[0045] Understandably, this embodiment improves the conversion efficiency from pulsating DC to low-voltage DC through high-frequency switching control technology; improves the energy release efficiency during the off-time period through the collaborative freewheeling design of power inductors and dual diodes; improves ripple suppression capability through the combination of input filtering with the seventh capacitor and output filtering with the ninth capacitor; and improves circuit reliability and reduces electromagnetic interference through integrated chip control.

[0046] Those skilled in the art can make corresponding equivalent improvements based on the application scenario, such as: replacing the second / third diode with a Schottky diode to reduce the forward voltage drop; or replacing the voltage divider resistor network with a digital potentiometer to achieve programmable output voltage; or introducing an active filter chip to replace the RC filter unit to optimize ripple suppression; or adding a bleed resistor in parallel with the power inductor to release residual energy during the off-period.

[0047] Preferred, see Figure 4 In a specific embodiment of the present invention, the linear constant current direct drive circuit 4 includes a first linear constant current direct drive chip U1 and a second linear constant current direct drive chip U2, both of which are BP5711EJ. The first input terminal (VIN pin) of the first linear constant current direct drive chip U1 is connected to the output terminal of the rectifier module 2, and the second input terminal (DIM pin) is connected to the first output terminal (pin 7) of the dimming and color-tuning control chip U4. It drives the cold light LED with constant current based on the first PWM signal (PWM_C) and adjusts the brightness. The first input terminal (VIN pin) of the second linear constant current direct drive chip U2 is connected to the output terminal of the rectifier module 2, and the second input terminal (DIM pin) is connected to the second output terminal (pin 8) of the dimming and color-tuning control chip. It drives the warm light LED with constant current based on the second PWM signal (PWM_W) and adjusts the brightness. The target color temperature is adjusted by mixing cold light and warm light.

[0048] Understandably, this embodiment uses two independent linear constant current chips of the same model to drive the cold light and warm light LEDs respectively, thereby achieving precise and independent control of the LED currents, improving the breadth of the color temperature adjustment range and the accuracy of the mixing ratio; and improves the system integration and reduces the complexity of peripheral circuits and overall cost by using a simple architecture that shares the rectified pulsating DC power as the input power.

[0049] Those skilled in the art can make corresponding equivalent improvements based on the application scenario. For example, the linear constant current direct drive chip BP5711EJ can be replaced with a similar chip to adapt to different cost or performance requirements; or an integrated dual-channel linear constant current drive chip can be used to further optimize the circuit board layout and the number of components; or a discrete MOS transistor can be used with an operational amplifier and a reference voltage source to build an external constant current control circuit to achieve a custom and flexible configuration of the drive current limit value.

[0050] Preferred, see Figure 7In a specific embodiment of the present invention, the dimming and color-tuning control module 3 further includes a fourth resistor R34, a fifth resistor R35, a sixth resistor R36, a seventh resistor R37, a tenth capacitor C15, and an eleventh capacitor C16; the first output terminal 7 (PWM_C) of the dimming and color-tuning control chip U4 is connected to the first terminal of the fourth resistor R34, and the second terminal of the fourth resistor R34, the first terminal of the fifth resistor R35, and the first terminal of the tenth capacitor C15 are all connected to the second input terminal of the linear constant current direct drive circuit 4 (the DIM pin of the cold light driver chip U1), forming a cold light... The RC filter network for the light PWM signal is as follows: Pin 8 (PWM_W), the second output terminal of the dimming and color-tuning control chip, is connected to the first terminal of the sixth resistor R36. The second terminal of the sixth resistor R36, the first terminal of the seventh resistor R37, and the first terminal of the eleventh capacitor C16 are all connected to the third input terminal of the linear constant current direct drive circuit 4 (the DIM pin of the warm light driver chip U2), forming the RC filter network for the warm light PWM signal. The second terminals of the fifth resistor 35, the seventh resistor 37, the tenth capacitor C15, and the eleventh capacitor C16 are all grounded. Among them, the fourth resistor R34 and the sixth resistor R36 are used to limit the peak value of the drive current, the fifth resistor R35 and the seventh resistor R37 are used to set the signal load impedance, and the tenth capacitor C15 and the eleventh capacitor C16 are used to filter out the high-frequency switching noise of the PWM. Together, they convert the square wave signal into a smooth trapezoidal wave, eliminate the transient current impact of the LED drive, and finally output two pure analog dimming signals to the control terminal of the cold light / warm light driver circuit to realize independent adjustment of the color temperature of the dual channels. Furthermore, capacitors C13 and C14 are connected in parallel between the VDD pin of the dimming and color tuning chip U4 and ground. These capacitors are used to filter out high-frequency switching noise and low-frequency ripple on the power line, stabilize the VDD power supply voltage fluctuation, and prevent PWM signal jitter caused by power grid disturbances.

[0051] Understandably, this embodiment improves the anti-interference capability of the PWM signal through an RC low-pass filter network; reduces the input stress of the LED driver chip through resistor current limiting design; eliminates LED flicker caused by high-frequency switching noise through capacitor waveform smoothing; and improves the consistency of cold / warm light brightness adjustment through dual-channel independent conditioning.

[0052] Those skilled in the art can make corresponding equivalent improvements based on the application scenario, such as: replacing the fixed resistor with an adjustable resistor to achieve dynamic optimization of the filtering characteristics; or using an LC filter to replace the RC network to enhance high-frequency suppression; or adding a TVS tube in parallel to the PWM output terminal to provide electrostatic protection; or using a digital isolator to achieve electrical isolation of the signal; or introducing a buffer amplifier to improve the signal driving capability.

[0053] Preferably, the three-phase thyristor dimming module 1 includes three-phase dimming circuits with identical structures, corresponding to the LA, LB, and LC phase inputs respectively; each phase dimming circuit includes a bidirectional thyristor, a bidirectional trigger diode, an adjustable resistor, and a buffer absorption network; the first control electrode of the bidirectional thyristor is connected to the first end of the adjustable resistor and the phase line input terminal, the gate of the bidirectional thyristor is connected to the first end of the bidirectional trigger diode, and the second end of the adjustable resistor is connected to the second end of the bidirectional trigger diode; the buffer absorption network is arranged in parallel between the first and second control electrodes of the bidirectional thyristor.

[0054] See Figure 3 In one specific embodiment of the present invention, the three-phase thyristor dimming module is configured with three sets of independent and symmetrical sub-circuits: LA phase modulation photonic circuit: Fuse F1 is connected in series at the LA line input terminal. The output of fuse F1 is connected to the first control electrode of bidirectional thyristor BTA1, the first terminal of transient voltage suppressor TVS1, the first terminal of resistor R18, and the first terminal of adjustable resistor RT1. The second terminal of adjustable resistor RT1 is connected in series with resistor R38 and then connected to the first terminal of resistor R16, the first terminal of capacitor C7, and the second terminal of bidirectional trigger diode DB1. The first terminal of bidirectional trigger diode DB1 is connected to the gate of bidirectional thyristor BTA1. The second terminal of resistor R18 is connected to the first terminal of capacitor C8. The second control electrode of bidirectional thyristor BTA1 is connected to the second terminal of resistor R16, the second terminal of capacitor C7, the second terminal of transient voltage suppressor TVS1, and the second terminal of capacitor C8. Among them, fuse F1 provides overcurrent protection; transient voltage suppressor TVS1 is connected in parallel between the two control electrodes of bidirectional thyristor BTA1 to form a transient voltage clamping barrier, which can effectively absorb power grid surges; adjustable resistor RT1 and fixed resistor R38 form a phase adjustment RC network, which can precisely control the conduction angle by changing the charging time of C7; bidirectional trigger diode DB1, together with resistor R16 and capacitor C7, forms a critical conduction trigger, which triggers the bidirectional thyristor BTA1 to conduct when the voltage of C7 reaches the threshold of bidirectional trigger diode DB1; resistor R18 and capacitor C8 are connected in parallel between the two control electrodes of bidirectional thyristor BTA1 to form a series RC absorption network to suppress voltage spikes during the turn-off period.

[0055] LB phase modulation photonic circuit: Fuse F2 is connected in series at the LB line input terminal. The output of fuse F2 is connected to the first control electrode of bidirectional thyristor BTA2, the first terminal of transient voltage suppressor TVS2, the first terminal of resistor R30, and the first terminal of adjustable resistor RT2. The second terminal of adjustable resistor RT2 is connected in series with resistor R39 and then connected to the first terminal of resistor R25, the first terminal of capacitor C10, and the second terminal of bidirectional trigger diode DB2. The first terminal of bidirectional trigger diode DB2 is connected to the gate of bidirectional thyristor BTA2. The second terminal of resistor R30 is connected to the first terminal of capacitor C11. The second control electrode of bidirectional thyristor BTA2 is connected to the second terminal of resistor R25, the second terminal of capacitor C10, the second terminal of transient voltage suppressor TVS2, and the second terminal of capacitor C11. Among them, fuse F2 provides overcurrent protection; transient voltage suppressor TVS2 is connected in parallel between the two control electrodes of bidirectional thyristor BTA2 to form a transient voltage clamping barrier, which can effectively absorb power grid surges; adjustable resistor RT2 and fixed resistor R39 form a phase adjustment RC network, which can precisely control the conduction angle by changing the charging time of C10; bidirectional trigger diode DB2, together with resistor R25 and capacitor C10, forms a critical conduction trigger, which triggers the bidirectional thyristor BTA2 to conduct when the voltage of C10 reaches the threshold of bidirectional trigger diode DB2; resistor R30 and capacitor C11 are connected in parallel between the two control electrodes of bidirectional thyristor BTA2 to form a series RC absorption network to suppress voltage spikes during the turn-off period.

[0056] LC phase modulation photonic circuit: Fuse F3 is connected in series at the LC line input terminal. The output of fuse F3 is connected to the first control electrode of bidirectional thyristor BTA3, the first terminal of transient voltage suppressor TVS3, the first terminal of resistor R33, and the first terminal of adjustable resistor RT3. The second terminal of adjustable resistor RT3 is connected in series with resistor R40 and then connected to the first terminal of resistor R32, the first terminal of capacitor C12, and the second terminal of bidirectional trigger diode DB3. The first terminal of bidirectional trigger diode DB3 is connected to the gate of bidirectional thyristor BTA3. The second terminal of resistor R33 is connected to the first terminal of capacitor C6. The second control electrode of bidirectional thyristor BTA3 is connected to the second terminal of resistor R32, the second terminal of capacitor C12, the second terminal of transient voltage suppressor TVS3, and the second terminal of capacitor C6. Among them, fuse F3 provides overcurrent protection; transient voltage suppressor TVS3 is connected in parallel between the two control electrodes of bidirectional thyristor BTA3 to form a transient voltage clamping barrier, which can effectively absorb power grid surges; adjustable resistor RT3 and fixed resistor R40 form a phase adjustment RC network, which can precisely control the conduction angle by changing the charging time of C12; bidirectional trigger diode DB3, together with resistor R32 and capacitor C12, forms a critical conduction trigger, which triggers the bidirectional thyristor BTA3 to conduct when the voltage of C12 reaches the threshold of bidirectional trigger diode DB3; resistor R33 and capacitor C6 are connected in parallel between the two control electrodes of bidirectional thyristor BTA3 to form a series RC absorption network to suppress voltage spikes during the turn-off period.

[0057] Understandably, this embodiment improves the conduction angle control accuracy and phase synchronization through the collaborative triggering mechanism of bidirectional thyristors and bidirectional trigger diodes; it achieves continuous and precise dimming of the conduction angle over a large angle range by flexibly adjusting the RC time constant through adjustable resistors; it reduces thyristor switching losses, improves system reliability, and extends device life by dynamically suppressing commutation overvoltage and turn-off spikes through a buffer absorption network; and it improves grid load balance and phase control consistency through a three-phase independent symmetrical topology.

[0058] Those skilled in the art can make corresponding equivalent improvements based on the application scenario, such as: using an integrated buffer module to simplify the absorption network design; or replacing the adjustable resistor with a digital potentiometer to support remote programmable control; or introducing a temperature compensation circuit to automatically correct conduction angle drift; or using a solid-state relay to build a contactless switch to replace the mechanical trigger structure.

[0059] Preferably, the system also includes a three-phase lightning protection module 8, which comprises a primary lightning protection circuit 81, a secondary lightning protection circuit 82, and a tertiary lightning protection circuit 83. The primary lightning protection circuit 81 includes a varistor and a gas discharge tube connected in series between each pair of phase lines, and a varistor and a gas discharge tube connected in series between each phase line and ground, for discharging common-mode and differential-mode surge energy. The secondary lightning protection circuit 82 has its input terminal connected to the output terminal of the primary lightning protection circuit, and includes an inductor and a gas discharge tube connected in parallel in each phase line, a transient voltage suppression diode connected between each pair of phase lines, and a transient voltage suppression diode and a gas discharge tube connected in series between each phase line and ground, for further clamping transient overvoltages. The tertiary lightning protection circuit 83 has its input terminal connected to the output terminal of the secondary lightning protection circuit, and includes a capacitor connected between each pair of phase lines and a capacitor connected between each phase line and ground, for absorbing residual surge energy and suppressing high-frequency interference.

[0060] For details, see Figure 8 In a specific embodiment of the present invention, the first-level surge protection circuit 81 specifically includes: three-phase input lines (LA, LB, LC) connected in series with fuses (F01, F02, F03); a first varistor RV01 and a first gas discharge tube GDT01 connected in series are connected between the LA line and the LB line; a second varistor RV02 and a second gas discharge tube GDT02 connected in series are connected between the LB line and the LC line; a third varistor RV03 and a third gas discharge tube GDT03 connected in series are connected between the LA line and the LC line; the LA line is connected to the first end of the fourth gas discharge tube GDT04 through a fourth varistor RV04, the LB line is connected to the first end of the fourth gas discharge tube GDT04 through a fifth varistor RV05, the LC line is connected to the first end of the fourth gas discharge tube GDT04 through a sixth varistor RV06, and the second end of the fourth gas discharge tube GDT04 is grounded.

[0061] The working process is as follows: After the three-phase AC power is input, it forms a collaborative protection network through fuses F01-F03, varistors RV01-RV06, and gas discharge tubes GDT01-GDT04. Under normal operating conditions without lightning strikes or overvoltages, the fuses remain in the conducting state, and the varistors and gas discharge tubes are in a high-resistance state, which does not affect the transmission path of the three-phase AC power—the current flows from the LA line through F01 to the load and then through the LB line to form a loop. In a three-phase three-wire system, there are three core current loops: LA to LB, LA to LC, and LB to LC. When encountering lightning strikes or transient overvoltages, the impedance of the varistor drops sharply and the gas discharge tubes conduct instantaneously. When voltage occurs between two phase lines, the GDT01 / RV01 combination across the LA-LB line, the GDT02 / RV02 combination across the LB-LC line, and the GDT03 / RV03 combination across the LA-LC line respond synchronously. The gas discharge tubes GDT01-GDT03 break down and conduct, forming a low-impedance path. The resistance of the varistor RV01-RV03 drops sharply, directly discharging the phase-to-phase overvoltage energy to the adjacent phase line. At the same time, the phase-to-ground overvoltage energy is discharged to the ground through RV04-RV06, triggering GDT04. If the overcurrent continues to exceed the set threshold, the fuses F01-F03 will melt and cut off the circuit to prevent equipment damage.

[0062] Understandably, this embodiment improves the coordinated discharge capability of phase-to-phase overvoltage through the combined bridging design of varistors and gas discharge tubes; improves the absorption efficiency of phase-to-ground surge energy through the fourth gas discharge tube structure with an independent ground discharge path; improves the overall lightning protection module's operating speed and energy tolerance through the division of labor and cooperation of multi-level response mechanisms; improves the reliability of overcurrent protection through the topology design of fuses connected in series with the three-phase input lines; and improves the equipment survival rate under complex lightning strike conditions through the dual-path coordination of phase-to-phase protection and ground protection.

[0063] Those skilled in the art can make corresponding equivalent improvements based on the application scenario, such as replacing the varistor with a metal oxide rheostat (MOV) to be compatible with different surge standards; or replacing the gas discharge tube with a spark gap device to reduce the trigger voltage.

[0064] For details, see Figure 8In a specific embodiment of the present invention, the secondary surge protection circuit 82 includes: the LA line includes a first inductor L01 and a fifth gas discharge tube GDT05 connected in parallel; the LB line includes a second inductor L02 and a sixth gas discharge tube GDT06 connected in parallel; and the LC line includes a third inductor L03 and a seventh gas discharge tube GDT07 connected in parallel. The second terminal of the first inductor L01 is connected to the first terminal of the first transient voltage suppression diode TVS01, the first terminal of the third transient voltage suppression diode TVS03, and the first terminal of the fourth transient voltage suppression diode TVS04. The second terminal of the second inductor L02 is connected to the second terminal of the first transient voltage suppression diode TVS01 and the second transient voltage suppression diode TVS04. The first terminal of the suppression diode TVS02 and the first terminal of the fifth transient voltage suppression diode TVS05 are connected; the second terminal of the third inductor L03 is connected to the second terminal of the second transient voltage suppression diode TVS02, the second terminal of the third transient voltage suppression diode TVS03, and the first terminal of the sixth transient voltage suppression diode TVS06; the second terminals of the fourth transient voltage suppression diode TVS04, the second terminals of the fifth transient voltage suppression diode TVS05, and the second terminal of the sixth transient voltage suppression diode TVS06 are all connected to the first terminal of the eighth gas discharge tube GDT08, and the second terminal of the eighth gas discharge tube GDT08 is grounded; a capacitor C27 is connected across the two ends of the eighth gas discharge tube GDT08.

[0065] The working process is as follows: After being protected by the first-level surge protection circuit 81, the three-phase AC power is input to the parallel branch of inductors (L01-L03) and gas discharge tubes (GDT05-GDT07); under normal operating conditions, gas discharge tubes GDT05-GDT07 and TVS01-TVS06 are all in a high-resistance state, and the impedance of inductors L01-L03 to the power frequency current is negligible, so the power is transmitted to the subsequent stage without loss; when a residual surge overvoltage occurs, gas discharge tubes GDT05-GDT07 conduct first to discharge most of the energy to ground; inductors L01-L03 suppress the current mutation rate and delay the formation of the overvoltage peak; transient voltage suppression diodes TVS01-TVS06 then reverse break down, clamping the phase-to-phase and phase-to-ground voltages to the safe threshold; capacitor C27 absorbs the high-frequency oscillation energy and works with GDT08 to establish the final discharge path to ground, realizing multi-stage attenuation surge suppression.

[0066] Understandably, this embodiment improves the shunting efficiency of high-frequency surge energy by using a parallel topology of inductors and gas discharge tubes; improves the coordinated clamping accuracy of phase-to-phase and phase-to-ground residual voltages by using a grouped transient voltage suppression diode layout; improves the thoroughness of oscillation energy absorption by using a capacitor and gas discharge tube end coupling design; improves the speed and reliability of overall protection response by using a refined coordination of multi-stage response timing; and improves the instantaneous overcurrent protection capability for downstream circuits by using the inductor current suppression characteristics.

[0067] For details, see Figure 8In a specific embodiment of the present invention, the three-level surge protection circuit 83 includes: a capacitor C21 connected between the LA line and the LB line, a capacitor C22 connected between the LB line and the LC line, a capacitor C23 connected between the LA line and the LC line; a capacitor C24 connected between the LA line and ground, a capacitor C25 connected between the LB line and ground, and a capacitor C26 connected between the LC line and ground.

[0068] The working process is as follows: Capacitor group C21-C26 constitutes a high-frequency noise absorption network; under normal operating conditions, the capacitors have high impedance to 50 / 60Hz power frequency AC, and the current is mainly transmitted along the three-phase circuits LA to LB, LA to LC, and LB to LC, and the capacitor leakage current is negligible; when lightning strikes or electromagnetic interference generate high-frequency noise, differential mode capacitors C21-C23 have low impedance to phase-to-phase differential mode interference, guiding the interference current to form a closed loop between the phase lines to cancel the energy; common mode capacitors C24-C26 have low impedance to ground common mode interference, conducting the noise current to the ground; through the synergistic effect of differential and common mode paths, residual high-frequency interference is completely filtered out, ensuring that the subsequent circuits are not affected by transient overvoltages.

[0069] Understandably, this embodiment improves the efficiency of eliminating high-frequency interference between phases through the cross-phase current conduction design of differential-mode capacitors; improves the discharge balance of common-mode noise through the three-phase symmetrical grounding layout of common-mode capacitors; improves the purity of power transmission through the impedance difference response between power frequency and high frequency; improves electromagnetic compatibility performance through the wideband coverage of passive filter network; and improves the system's anti-interference reliability through the positioning of final-stage fine protection.

[0070] Preferred, see Figure 7 In a specific embodiment of the present invention, the drive control circuit further includes a sensing module 9. The input terminal of the sensing module 9 is connected to the output terminal of the rectifier module 2, and the output terminal is connected to the second input terminal (pins 12 and 13) of the dimming and color adjustment control chip U4, which is used to collect human movement signals and / or ambient light intensity signals to trigger automatic dimming and color adjustment operations.

[0071] The working process is as follows: The pulsating DC power output by the rectifier module provides power to the sensing module. In this embodiment, the sensing module 9 uses a radar sensor, model EDC15C-30N-05, which can accurately detect human movement within a region by emitting 5.8GHz high-frequency electromagnetic waves and receiving reflected signals. When human activity is detected, the sensor sends a high-level trigger signal to the dimming and color-changing control chip U4 through the interface, generating a lighting control command. Due to its high operating frequency of 5.8GHz, it has excellent penetration ability and anti-interference performance, enabling it to accurately detect human movement in complex environments and avoid false triggering or missed triggering. At the same time, the sensor's trigger delay is set to 30 seconds. When human movement is detected, the lamp remains on for 30 seconds. If no new activity is detected during this period, it automatically turns off or reduces brightness. In dimly lit places such as underground parking garages where human activity is infrequent, the microwave radar sensor can accurately detect the movement of vehicles or people and trigger the lamp to switch to a high-brightness mode to provide sufficient illumination. When people leave, the lamp automatically returns to the basic brightness or turns off, significantly reducing energy consumption. Furthermore, the sensing module can also be selected from other models, while integrating a photosensitive sensor to collect ambient light intensity in real time and convert it into a linear voltage signal. When the ambient light intensity is lower than a preset threshold, the photosensitive sensor outputs a low-level trigger signal to the dimming and color-adjusting control chip U4, and the chip automatically increases the PWM duty cycle to enhance the lighting brightness. When the ambient light intensity exceeds the threshold, the sensor outputs a high-level signal to trigger U4 to reduce the output brightness. In corridor scenarios with sufficient natural light, the system automatically maintains a low-brightness energy-saving state. When there is insufficient light on cloudy or rainy days or at night, it dynamically increases to the target brightness value to achieve light-sensing adaptive adjustment.

[0072] Understandably, this embodiment improves the intelligent adaptability of lighting scenarios through a multi-sensor fusion environmental parameter acquisition mechanism; improves the accuracy of energy-saving dimming through the coordinated triggering logic of human movement and ambient light; improves the real-time response of the sensing module through a rectifier direct-drive power supply architecture; improves the anti-interference capability of control commands through a digital level signal transmission design; and improves the convenience of user experience through an unattended automatic dimming strategy.

[0073] Compared with the prior art, the beneficial effects of the present invention include at least the following: This invention proposes a three-phase linear direct-drive dimming and color-tuning circuit. By using a three-phase rectified direct-drive output of high-frequency pulsating DC power, it completely eliminates the flickering phenomenon of traditional single-phase circuits, solving the problems of visual fatigue and camera flicker interference. Through a linear constant-current drive circuit with no electrolytic capacitors, it avoids the short lifespan of traditional drive circuits, significantly improving the lifespan of the drive circuit. Using dual-channel phase-synchronous PWM control technology, combined with cold / warm light constant-current drive, it achieves high-precision stepless mixing and adjustment of brightness and color temperature. The three-phase rectified direct-drive architecture eliminates the traditional switching power supply conversion stage, improving system efficiency. Integrated control via a dimming and color-tuning integrated chip simplifies the circuit structure, reduces electromagnetic interference, and improves electromagnetic compatibility and cost advantages.

[0074] Furthermore, this invention also employs a physical isolation design of dual three-phase full-bridge rectifier circuits to prevent power loop noise from coupling to the control chip, thereby improving the sampling accuracy and anti-interference capability of the control signal and enhancing system stability; a dedicated phase detection circuit in the first rectifier circuit improves zero-crossing positioning accuracy; an independent drive of the cold / warm LEDs in the second rectifier circuit improves power transmission efficiency and reduces crosstalk distortion; dynamic clamping of overvoltage spikes in the bleeder circuit improves the stability of the phase sampling signal; a composite filter network filters out high-frequency interference, improving zero-crossing detection accuracy; and coordinated bleedering and filtering enhance the anti-interference capability of the control chip. The overvoltage protection system employs a Zener diode for precise threshold triggering, improving overvoltage protection response speed; a cascaded power switch structure driven by a transistor enhances the reliability of the discharge path; efficient energy dissipation through a discharge resistor network improves voltage clamping stability and system safety; reverse blocking design of the first diode enhances the transistor's base anti-interference capability; a parallel RC network at the base suppresses the risk of high-frequency false triggering; a source-connected capacitor absorbs transient spikes from the switch, reducing voltage stress on the power transistor; multi-stage collaborative protection improves discharge stability and system reliability; and a voltage divider resistor network provides network voltage reduction, improving high-voltage signal acquisition. Safety features include: improved anti-interference capability across the entire frequency band through multi-capacitor parallel wideband filtering; improved phase signal extraction accuracy through dual-stage RC low-pass filtering; efficient conversion of pulsating DC to stable low-voltage DC through a constant voltage circuit, improving power supply stability for the control chip and color adjustment module; enhanced energy transfer continuity through the synergistic effect of power inductor magnetic energy conversion and freewheeling diodes; improved PWM signal anti-interference through an RC filter network composed of the fifth and seventh resistors and the tenth and eleventh capacitors; improved accuracy and flexibility of color temperature adjustment through independent driving of cold and warm LEDs by two PWM signals; and improved linear constant current control. Improve brightness stability and LED lifespan; enhance the consistency of brightness adjustment accuracy between cold and warm light through a dual-channel independent filtering architecture; improve grid load balance and phase control consistency through a three-phase independent symmetrical topology design; achieve conduction angle accuracy through coordinated adjustment of adjustable resistors and bidirectional trigger diodes; improve thyristor lifespan by suppressing commutation overvoltage and turn-off spikes through a buffer absorption network; improve system reliability and stability in harsh grid environments by discharging and absorbing surge energy through a multi-level lightning protection design; and improve circuit anti-interference capability and lifespan by suppressing high-frequency interference and clamping transient overvoltages.

[0075] In summary, this invention solves the technical problems of severe flicker, high electromagnetic interference, low three-phase compatibility, and short lifespan of existing LED three-phase driving circuits.

[0076] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A three-phase linear direct-drive dimming and color-tuning circuit, characterized in that, include: The three-phase thyristor dimming and color-tuning module (1) is connected to three-phase AC power at its input end. It includes a phase angle control unit and a mode switching unit. The phase angle control unit is used to adjust the phase angle of the output AC voltage. The mode switching unit sends a mode switching signal by adjusting the waveform of the output AC voltage. The rectifier module (2) has its input end connected to the output end of the three-phase thyristor dimming and color-tuning module (1) and is used to convert AC power into pulsating DC power. The dimming and color-tuning control module (3) includes a dimming and color-tuning control chip; the first input terminal of the dimming and color-tuning control chip is connected to the output terminal of the rectifier module (2), obtains the voltage waveform and phase information of the pulsating DC power, generates two phase-synchronized PWM dimming signals based on the phase information, and switches the dimming mode and color-tuning mode when the mode switching signal is detected in the voltage waveform; The linear constant current direct drive circuit (4) has a first input terminal connected to the output terminal of the rectifier module (2) and a second input terminal connected to the first output terminal of the dimming and color-tuning control chip. It drives the cold light LED with constant current based on the first PWM signal and adjusts the brightness of the cold light. The third input terminal is connected to the second output terminal of the dimming and color tuning control chip. Based on the second PWM signal, the warm light LED is driven by constant current and the brightness of the warm light is adjusted. The target color temperature is generated by mixing the cold light and the warm light.

2. The three-phase linear direct-drive dimming and color-tuning circuit as described in claim 1, characterized in that, The rectifier module (2) includes a first three-phase full-bridge rectifier circuit (21), a second three-phase full-bridge rectifier circuit (22), a bleeder circuit (5), and a phase sampling filter circuit (6); the input terminal of the first three-phase full-bridge rectifier circuit (21) and the input terminal of the second three-phase full-bridge rectifier circuit (22) are respectively connected to the output terminal of the three-phase thyristor dimming and color-tuning module (1); the output terminal of the first three-phase full-bridge rectifier circuit (21) is connected to the input terminal of the bleeder circuit (5), the output terminal of the bleeder circuit (5) is connected to the input terminal of the phase sampling filter circuit (6), and the output terminal of the phase sampling filter circuit (6) is connected to the first input terminal of the dimming and color-tuning control chip; the output terminal of the second three-phase full-bridge rectifier circuit (22) is connected to the first input terminal of the linear constant current direct drive circuit (4).

3. The three-phase linear direct-drive dimming and color-tuning circuit as described in claim 2, characterized in that, The bleedering circuit (5) includes a Zener diode, a transistor, a power switch, a first voltage divider resistor network, and a bleedering resistor network. The input terminal of the first voltage divider resistor network is connected to the output terminal of the first three-phase full-bridge rectifier circuit (21). The first output terminal is connected to the cathode of the Zener diode, and the second output terminal is connected to the drain of the power switch. The anode of the Zener diode is connected to the base of the transistor, the collector of the transistor is connected to the gate of the power switch, and the emitter of the transistor is grounded. The source of the power switch is grounded through the bleedering resistor network. When the output voltage of the first three-phase full-bridge rectifier circuit (21) exceeds a set threshold, the Zener diode breaks down and conducts, triggering the transistor to conduct, thereby driving the power switch to open the bleedering path.

4. The three-phase linear direct-drive dimming and color-tuning circuit as described in claim 3, characterized in that, The discharge circuit (5) further includes a first diode, a first resistor, a first capacitor, and a second capacitor; the cathode of the first diode is connected to the base of the transistor, and the anode is connected to the source of the power switch; the first resistor and the first capacitor are connected in parallel between the base and emitter of the transistor; the second capacitor is connected across the source of the power switch and ground.

5. The three-phase linear direct-drive dimming and color-tuning circuit as described in claim 4, characterized in that, The phase sampling filter circuit (6) includes a second voltage divider resistor network, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a second resistor, and a third resistor; the input terminal of the second voltage divider resistor network is connected to the output terminal of the discharge circuit (5), and the output terminal is connected to the first terminal of the third capacitor, the first terminal of the fourth capacitor, and the first terminal of the second resistor; the second terminal of the second resistor is connected to the first terminal of the fifth capacitor and the first terminal of the third resistor, and the second terminal of the third resistor and the first terminal of the sixth capacitor are connected to the first input terminal of the dimming and color tuning control chip; the ground terminal of the second voltage divider resistor network, the second terminal of the third capacitor, the second terminal of the fourth capacitor, the second terminal of the fifth capacitor, and the second terminal of the sixth capacitor are all grounded.

6. The three-phase linear direct-drive dimming and color-tuning circuit as described in claim 2, characterized in that, It also includes a constant voltage circuit (7), which includes a constant voltage drive chip, a power inductor, a second diode, a third diode, a seventh capacitor, an eighth capacitor, and a ninth capacitor; the first input terminal of the constant voltage drive chip and the first terminal of the seventh capacitor are connected to the output terminal of the second three-phase full-bridge rectifier circuit (22), and the second input terminal is connected to the cathode of the second diode and the first terminal of the eighth capacitor; the ground terminal of the constant voltage drive chip is connected to the second terminal of the eighth capacitor, the first terminal of the power inductor, and the cathode of the third diode; the anode of the second diode is connected to the first terminal of the ninth capacitor and the second terminal of the power inductor, serving as the positive terminal of the output terminal of the constant voltage circuit (7); the second terminal of the seventh capacitor, the anode of the third diode, and the second terminal of the ninth capacitor are grounded.

7. The three-phase linear direct-drive dimming and color-tuning circuit as described in claim 1, characterized in that, The linear constant current direct drive circuit (4) includes a first linear constant current direct drive chip and a second linear constant current direct drive chip; the first input terminal of the first linear constant current direct drive chip is connected to the output terminal of the rectifier module (2), and the second input terminal is connected to the first output terminal of the dimming and color-tuning control chip, driving the cold light LED with constant current based on the first PWM signal and adjusting its brightness; the first input terminal of the second linear constant current direct drive chip is connected to the output terminal of the rectifier module (2), and the second input terminal is connected to the second output terminal of the dimming and color-tuning control chip, driving the warm light LED with constant current based on the second PWM signal and adjusting its brightness, thereby achieving target color temperature adjustment by mixing cold light and warm light.

8. The three-phase linear direct-drive dimming and color-tuning circuit as described in claim 1, characterized in that, The dimming and color-tuning control module (3) further includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a tenth capacitor, and an eleventh capacitor; the first output terminal of the dimming and color-tuning control chip is connected to the first terminal of the fourth resistor, and the second terminal of the fourth resistor, the first terminal of the fifth resistor, and the first terminal of the tenth capacitor are all connected to the second input terminal of the linear constant current direct drive circuit (4); the second output terminal of the dimming and color-tuning control chip is connected to the first terminal of the sixth resistor, and the second terminal of the sixth resistor, the first terminal of the seventh resistor, and the first terminal of the eleventh capacitor are all connected to the third input terminal of the linear constant current direct drive circuit (4); the second terminals of the fifth resistor, the seventh resistor, the tenth capacitor, and the eleventh capacitor are all grounded.

9. The three-phase linear direct-drive dimming and color-tuning circuit as described in any one of claims 1 to 8, characterized in that, The three-phase thyristor dimming module (1) includes three-phase dimming circuits with identical structures, corresponding to the LA, LB, and LC phase inputs respectively; each phase dimming circuit includes a bidirectional thyristor, a bidirectional trigger diode, an adjustable resistor, and a buffer absorption network; the first control electrode of the bidirectional thyristor is connected to the first end of the adjustable resistor and the phase line input terminal, the gate of the bidirectional thyristor is connected to the first end of the bidirectional trigger diode, and the second end of the adjustable resistor is connected to the second end of the bidirectional trigger diode; the buffer absorption network is arranged in parallel between the first and second control electrodes of the bidirectional thyristor.

10. The three-phase linear direct-drive dimming and color-tuning circuit as described in any one of claims 1 to 8, characterized in that, It also includes a three-phase lightning protection module (8), which includes a first-level lightning protection circuit (81), a second-level lightning protection circuit (82), and a third-level lightning protection circuit (83). The first-level lightning protection circuit (81) includes a varistor and a gas discharge tube connected in series between each two phase lines, and a varistor and a gas discharge tube connected in series between each phase line and ground, for discharging common-mode and differential-mode surge energy. The input terminal of the second-level lightning protection circuit (82) is connected to the output terminal of the first-level lightning protection circuit, including an inductor and a gas discharge tube connected in parallel in each phase line, a transient voltage suppression diode connected between each two phase lines, and a transient voltage suppression diode and a gas discharge tube connected in series between each phase line and ground, for further clamping transient overvoltage. The input terminal of the third-level lightning protection circuit (83) is connected to the output terminal of the second-level lightning protection circuit, including a capacitor connected between each two phase lines and a capacitor connected between each phase line and ground, for absorbing residual surge energy and suppressing high-frequency interference.

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