Novel phase-cut dimming power supply

Abstract

The invention relates to the technical field of LED illumination driving, in particular to a novel phase-cut dimming power supply. Comprising an AC input filtering and DC conversion circuit, an active power factor correction circuit, a flyback high-low voltage isolation conversion circuit, a synchronous rectification circuit, a voltage stabilizing circuit, a dimming circuit, a single-chip microcomputer control small board, a PWM signal-to-analog signal circuit, a phase cutting control circuit and an external load. According to the invention, the conduction angle and front and back edge information can be accurately analyzed, the detection precision is obviously improved, the stroboflash during deep dimming is eliminated, the dimming range is widened without flicker, dynamic holding current control data is generated, the light modulator can adapt to holding current requirements of different light modulators, the stable work of the light modulator is ensured, and the power consumption is reduced; besides, a novel PWM signal-to-analog signal circuit is adopted, so that the linearity and the anti-interference capability of signal conversion are greatly improved, stable output is ensured, and a high-compatibility and high-precision phase-cut dimming effect is realized.

Description

Technical Field

[0001] This invention relates to the field of LED lighting driving technology, specifically a novel phase-cut dimming power supply. Background Technology

[0002] Currently, in the field of LED lighting drivers, phase-cut dimming still occupies the mainstream market position due to its compatibility with traditional incandescent lamp dimming systems. Existing phase-cut dimming power supply technology usually includes the following structure: EMI filtering and rectification circuit at the input end, discharge circuit for maintaining the conduction of the thyristor, power factor correction circuit, DC-DC conversion circuit, and output rectification and filtering circuit.

[0003] In terms of control methods, most existing phase-cut dimming power supplies adopt analog detection technology or basic digital detection technology. The typical approach is to sample the input AC voltage by voltage division and use an RC filter circuit to smooth the voltage waveform after phase cutting to a DC level. The microcontroller or dedicated control chip determines the phase cutting angle by detecting the magnitude of this DC level, and then adjusts the output current of the power supply. In addition, in order to prevent the thyristor dimmer from being turned off due to insufficient current at low conduction angles, existing technologies usually use fixed RC discharge circuits or simple active discharge circuits to provide sustaining current. In terms of signal processing, traditional PWM to analog signal conversion often uses simple resistor-capacitor filtering or ordinary optocoupler isolation transmission, which has limited accuracy and response speed.

[0004] Although the aforementioned existing technologies can achieve basic phase-cut dimming functions, they still have the following obvious technical defects and shortcomings in practical applications:

[0005] Low detection accuracy and limited dimming range: Existing analog RC filter detection methods have a large phase lag and cannot restore the true details of the phase-cut waveform in real time. Especially in the small conduction angle (deep dimming) region, they are easily affected by input voltage noise and ripple, resulting in an uneven dimming curve. This often leads to problems such as a narrow dimming range, severe flickering at low brightness, or even light jitter.

[0006] Poor compatibility and weak adaptability: The market offers numerous brands of phase-cut dimmers, each with varying internal resistance characteristics, sustaining current requirements, and leading / trailing edge triggering methods. Existing fixed discharge circuits cannot dynamically adjust the sustaining current based on the characteristics of different dimmers. Excessive discharge current leads to reduced system efficiency and severe overheating; insufficient discharge current causes the dimmer to erroneously reset during phase cutting, resulting in flickering or "ghosting" phenomena.

[0007] Inaccurate identification of leading and trailing edges: Traditional detection circuits often have difficulty accurately distinguishing between leading-edge and trailing-edge phase cuts, or require additional complex hardware circuits for identification. This causes the power supply to be unable to automatically match the optimal control strategy when facing different types of dimmers, affecting the user experience.

[0008] Insufficient signal conversion stability: In the control signal transmission stage, the traditional PWM to analog circuit has poor linearity, is greatly affected by temperature and component aging, and is prone to output current drift. In addition, it is easy to lose signal accuracy during isolated transmission, making it difficult to meet the requirements of high-precision dimming.

[0009] Therefore, it is urgent to improve the phase-cut dimming power supply to solve the above-mentioned problems. Summary of the Invention

[0010] The purpose of this invention is to address the shortcomings of existing technologies, such as low detection accuracy of analog RC filters leading to limited dimming range, poor compatibility of fixed discharge circuits, difficulty in identifying leading and trailing edges, and poor linearity and instability of signal conversion. This invention provides a novel phase-cut dimming power supply that utilizes algorithms to fuse data and achieve digital waveform reconstruction. It can accurately analyze conduction angle and leading / trailing edge information, significantly improving detection accuracy and eliminating flicker during deep dimming. Simultaneously, it can adapt to the holding current requirements of different dimmers, ensuring stable dimmer operation while minimizing power consumption. The use of a novel PWM signal to analog signal conversion circuit greatly improves the linearity of signal conversion and anti-interference capability, ensuring stable output and achieving highly compatible and high-precision phase-cut dimming effects.

[0011] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0012] A novel phase-cut dimming power supply includes an AC input filter and DC conversion circuit, an active power factor correction circuit, a flyback high-low voltage isolation conversion circuit, a synchronous rectification circuit, a voltage regulator circuit, a dimming circuit, a microcontroller control board, a PWM signal to analog signal conversion circuit, a phase-cut control circuit, and an external load.

[0013] The output terminal of the AC input filter and DC conversion circuit is connected to the input terminal of the active power factor correction circuit.

[0014] The output terminal of the active power factor correction circuit is connected to the input terminal of the flyback high-low voltage isolation conversion circuit.

[0015] The output terminal of the flyback high-low voltage isolation converter circuit is connected to the input terminal of the synchronous rectifier circuit.

[0016] The output terminal of the synchronous rectifier circuit is connected to the input terminal of the voltage regulator circuit;

[0017] The output terminal of the voltage regulator circuit is connected to the input terminal of the flyback high-low voltage isolation conversion circuit;

[0018] The output terminal of the synchronous rectifier circuit is connected to the input terminal of the external load;

[0019] The input terminal of the dimming circuit is connected to the output terminal of the external load;

[0020] The control output terminal of the microcontroller control board is connected to the input terminal of the dimming circuit;

[0021] The output terminal of the AC input filter and DC conversion circuit is connected to the input terminal of the phase-cutting control circuit.

[0022] The output terminal of the phase-cutting control circuit is connected to the input terminal of the PWM signal to analog signal circuit;

[0023] The output terminal of the PWM signal to analog signal conversion circuit is connected to the input terminal of the microcontroller control board.

[0024] Compared with existing technologies, this invention has at least the following beneficial effects: By using algorithms to fuse data to achieve digital waveform reconstruction, it can accurately analyze conduction angle and leading and trailing edge information, significantly improving detection accuracy, eliminating flicker during deep dimming, and widening the dimming range without flicker. At the same time, by generating dynamic sustaining current control data, this patent can adapt to the sustaining current requirements of different dimmers, ensuring stable operation of the dimmer and minimizing power consumption. In addition, the use of a new PWM signal to analog signal circuit greatly improves the linearity of signal conversion and anti-interference capability, ensuring stable output and achieving a highly compatible and high-precision phase-cut dimming effect. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0026] Figure 1 This is a structural framework diagram of the novel phase-cut dimming power supply of the present invention;

[0027] Figure 2 This is the overall circuit diagram of the novel phase-cut dimming power supply of the present invention;

[0028] Figure 3 for Figure 2 Circuit diagram of AC input filtering and DC conversion circuit;

[0029] Figure 4 for Figure 2 Circuit diagram of active power factor correction circuit;

[0030] Figure 5 for Figure 2 Circuit diagram of a flyback high-low voltage isolation converter circuit;

[0031] Figure 6 for Figure 2 Circuit diagram of synchronous rectifier circuit;

[0032] Figure 7 for Figure 2 Circuit diagram of a medium voltage regulator circuit;

[0033] Figure 8 for Figure 2 Circuit diagram of the dimming circuit;

[0034] Figure 9 for Figure 2 Circuit diagram of a small board circuit controlled by a microcontroller;

[0035] Figure 10 for Figure 2 Circuit diagram of a PWM signal to analog signal converter;

[0036] Figure 11 for Figure 2 Circuit diagram of the phase-cut control circuit.

[0037] In the diagram: 1. AC input filtering and DC conversion circuit; 2. Active power factor correction circuit; 3. Flyback high-low voltage isolation conversion circuit; 4. Synchronous rectification circuit; 5. Voltage regulation circuit; 6. Dimming circuit; 7. Microcontroller control board; 8. PWM signal to analog signal conversion circuit; 9. Phase cutting control circuit; 10. External load. Detailed Implementation

[0038] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0039] like Figure 1-11 As shown, the novel phase-cut dimming power supply provided in this embodiment includes an AC input filtering and DC conversion circuit 1, an active power factor correction circuit 2, a flyback high-low voltage isolation conversion circuit 3, a synchronous rectification circuit 4, a voltage regulator circuit 5, a dimming circuit 6, a microcontroller control board 7, a PWM signal to analog signal conversion circuit 8, a phase-cut control circuit 9, and an external load 10.

[0040] AC input filtering and DC conversion circuit 1: Used to filter the input AC mains power, suppress electromagnetic interference (EMI), and convert AC to DC.

[0041] Active power factor correction circuit 2: It is used to correct the waveform and phase of the input current so that it follows the waveform of the input voltage, thereby improving the power factor and reducing the pollution of the power grid by harmonic current.

[0042] Flyback high-low voltage isolation converter circuit 3: Used to convert high-voltage DC to low-voltage AC through a high-frequency transformer, realizing electrical isolation between the input and output terminals and ensuring safe use.

[0043] Synchronous rectifier circuit 4: Used to rectify the transformer secondary side using MOSFET switches and a synchronous controller, replacing traditional rectifier diodes. It leverages the low on-resistance of MOSFETs to reduce rectification losses and improve power efficiency. It converts the AC to DC from the transformer secondary side.

[0044] Voltage regulator circuit 5: Used to sample and feedback regulate the output voltage after the synchronous rectification circuit to ensure the stability of the output voltage / current when the load changes or the input fluctuates.

[0045] Dimming circuit 6: Used to receive the dimming control signal output by the microcontroller control board 7, and ultimately control the brightness of the external load 10.

[0046] Microcontroller control board 7: As the core control unit, it is responsible for receiving phase angle data, performing logic operations, and outputting corresponding PWM control signals.

[0047] PWM signal to analog signal circuit 8: Receives PWM signals and converts them into analog signals; its core lies in the use of a specific circuit structure, which can convert the duty cycle change of digital PWM signals into high-precision, low-ripple analog voltage signals, thereby achieving high-fidelity signal transmission.

[0048] Phase-cutting control circuit 9: Real-time acquisition of the phase-cutting signal at the input terminal; secondly, fusion of the sampled data through internal algorithms to achieve digital reconstruction of the phase-cutting waveform; next, extraction of waveform features through algorithms to accurately analyze the conduction angle information (corresponding to dimming brightness) and the phase-cutting type information of the current phase-cutting dimmer; simultaneously, generation of control data for the sustaining current circuit based on the analyzed features, used to dynamically control the sustaining current circuit to ensure stable operation of the dimmer; finally, outputting a signal containing brightness information, which can be in the form of a PWM signal, a serial port signal, or other digitally encoded signals (such as Manchester encoding).

[0049] External load 10: LED load or lighting load.

[0050] The output terminal of the AC input filtering and DC conversion circuit 1 is connected to the input terminal of the active power factor correction circuit 2;

[0051] The output terminal of the active power factor correction circuit 2 is connected to the input terminal of the flyback high-low voltage isolation conversion circuit 3;

[0052] The output terminal of the flyback high-low voltage isolation conversion circuit 3 is connected to the input terminal of the synchronous rectification circuit 4;

[0053] The output terminal of the synchronous rectifier circuit 4 is connected to the input terminal of the voltage regulator circuit 5;

[0054] The output terminal of the voltage regulator circuit 5 is connected to the input terminal of the flyback high-low voltage isolation conversion circuit 3;

[0055] The output terminal of the synchronous rectifier circuit 4 is connected to the input terminal of the external load 10;

[0056] The input terminal of the dimming circuit 6 is connected to the output terminal of the external load 10;

[0057] The control output terminal of the microcontroller control board 7 is connected to the input terminal of the dimming circuit 6;

[0058] The output terminal of the AC input filter and DC conversion circuit 1 is connected to the input terminal of the phase-cutting control circuit 9;

[0059] The output terminal of the phase-cutting control circuit 9 is connected to the input terminal of the PWM signal to analog signal circuit 8;

[0060] The output terminal of the PWM signal to analog signal circuit 8 is connected to the input terminal of the microcontroller control board 7.

[0061] The novel phase-cut dimming power supply provided in this embodiment has the following working process, working principle, and effects:

[0062] AC input filtering and DC conversion circuit 1: Connect the AC mains power to AC input filtering and DC conversion circuit 1 to filter out electromagnetic interference (EMI) and convert AC power to DC power.

[0063] Active power factor correction circuit 2: The DC input to the active power factor correction circuit 2 is controlled by the control circuit to correct the current waveform and phase.

[0064] Flyback high-low voltage isolation converter circuit 3: The corrected high voltage DC power is input into the flyback high-low voltage isolation converter circuit 3, and the voltage is stepped down and electrically isolated through a high frequency transformer.

[0065] Synchronous rectifier circuit 4: The low-voltage AC power after isolation conversion is input into the synchronous rectifier circuit 4, and rectified by MOSFET switching transistors.

[0066] Voltage regulator circuit 5: The rectified DC power is input into the voltage regulator circuit 5, sampled, and the feedback signal is transmitted to the flyback high-low voltage isolation converter circuit 3 to adjust the output.

[0067] Microcontroller control board 7: As the core control unit, it is responsible for receiving phase angle data, performing logic operations, and outputting corresponding PWM control signals.

[0068] PWM signal to analog signal circuit 8: Receives PWM signals and converts them into analog signals; its core lies in the use of a specific circuit structure, which can convert the duty cycle change of digital PWM signals into high-precision, low-ripple analog voltage signals, thereby achieving high-fidelity signal transmission.

[0069] Phase-cutting control circuit 9: Real-time acquisition of the phase-cutting signal at the input terminal; secondly, fusion of the sampled data through internal algorithms to achieve digital reconstruction of the phase-cutting waveform; next, extraction of waveform features through algorithms to accurately analyze the conduction angle information (corresponding to dimming brightness) and the phase-cutting type information of the current phase-cutting dimmer; simultaneously, generation of control data for the sustaining current circuit based on the analyzed features, used to dynamically control the sustaining current circuit to ensure stable operation of the dimmer; finally, outputting a signal containing brightness information, which can be in the form of a PWM signal, a serial port signal, or other digitally encoded signals (such as Manchester encoding).

[0070] External load 10: LED load or lighting load.

[0071] First, the phase-cut AC power passes through the AC input filter and DC conversion circuit 1, then the EMI filter circuit filters out electromagnetic interference and the DC power is converted by the rectifier bridge, thus providing a clean power input for the subsequent circuits and suppressing the interference of grid noise on the system. Subsequently, the DC power enters the active power factor correction circuit 2.

[0072] The waveform and phase of the input current are corrected by power factor correction technology to make it follow the waveform of the input voltage, so as to significantly improve the power factor and reduce the pollution of the power grid by harmonic current. Then, the processed high voltage DC power is input to the flyback high-low voltage isolation conversion circuit 3.

[0073] A high-frequency transformer is used to convert high-voltage electricity to low-voltage electricity, while achieving electrical isolation between the input and output terminals to ensure electrical safety. The converted low-voltage AC power is rectified by a synchronous rectifier circuit 4, which uses a MOSFET switch with low on-resistance to replace the traditional diode for rectification, effectively reducing rectification losses and improving the overall conversion efficiency of the power supply. The rectified current is sampled and regulated by a voltage regulator circuit 5 to ensure the stability of the output when the load changes.

[0074] Meanwhile, the phase-cut control circuit 9 acquires the AC phase-cut voltage waveform in real time, reconstructs the waveform by fusing the data through an internal algorithm, analyzes the conduction angle, leading and trailing edge types, and dimming brightness information, and generates sustaining current control data to ensure stable conduction of the dimmer and outputs a dimming signal to a new type of PWM signal to analog signal circuit 8 for filtering. This linearly converts the duty cycle change of the digital PWM signal into a high-precision, low-ripple analog voltage signal, thereby achieving high-fidelity signal transmission to the microcontroller control board 7, which is responsible for receiving the dimming signal, performing logic operations, and outputting the corresponding PWM dimming control signal to the dimming circuit 6. Based on this, the output current flowing to the external load 10 or the on / off duty cycle is adjusted to control the brightness of the load.

[0075] This invention has the following beneficial effects: By using algorithms to fuse data to achieve digital waveform reconstruction, it can accurately analyze conduction angle and leading and trailing edge information, significantly improving detection accuracy, eliminating flicker during deep dimming, and widening the dimming range without flicker. At the same time, by generating dynamic sustaining current control data, this patent can adapt to the sustaining current requirements of different dimmers, ensuring stable operation of the dimmer and minimizing power consumption. In addition, the use of a new PWM signal to analog signal circuit greatly improves the linearity of signal conversion and anti-interference ability, ensuring stable output and achieving a highly compatible and high-precision phase-cut dimming effect.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A novel phase-cut dimming power supply, characterized in that, It includes an AC input filter and DC conversion circuit (1), an active power factor correction circuit (2), a flyback high-low voltage isolation conversion circuit (3), a synchronous rectification circuit (4), a voltage regulator circuit (5), a dimming circuit (6), a microcontroller control board (7), a PWM signal to analog signal conversion circuit (8), a phase cutting control circuit (9), and an external load (10). The output terminal of the AC input filter and DC conversion circuit (1) is connected to the input terminal of the active power factor correction circuit (2); The output terminal of the active power factor correction circuit (2) is connected to the input terminal of the flyback high-low voltage isolation conversion circuit (3); The output terminal of the flyback high-low voltage isolation converter circuit (3) is connected to the input terminal of the synchronous rectifier circuit (4); The output terminal of the synchronous rectifier circuit (4) is connected to the input terminal of the voltage regulator circuit (5); The output terminal of the voltage regulator circuit (5) is connected to the input terminal of the flyback high-low voltage isolation converter circuit (3); The output terminal of the synchronous rectifier circuit (4) is connected to the input terminal of the external load (10); The input terminal of the dimming circuit (6) is connected to the output terminal of the external load (10); The control output terminal of the microcontroller control board (7) is connected to the input terminal of the dimming circuit (6); The output terminal of the AC input filter and DC conversion circuit (1) is connected to the input terminal of the phase-cutting control circuit (9); The output terminal of the phase-cutting control circuit (9) is connected to the input terminal of the PWM signal to analog signal circuit (8); The output terminal of the PWM signal to analog signal circuit (8) is connected to the input terminal of the microcontroller control board (7).

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