LED high-voltage dimming control system

Abstract

The utility model discloses an LED high-voltage dimming control system which comprises a system power supply module, a phase zero-cross detection circuit module, a bidirectional silicon controlled rectifier drive circuit module, an AD conversion circuit module, a communication display module, an LED lighting load and an MCU single-chip microcomputer control center unit. The stability is higher; the MCU single-chip microcomputer controls accurate program delay calculation of pulses output by the center unit, so that the dimming fineness is ensured, and the dimming of the LED lighting load is smoother.

Description

Technical Field

[0001] The utility model belongs to the technical field of LED intelligent lighting, and in particular relates to an LED high-voltage dimming control system. Background Art

[0002] In the current application of LED lighting fixtures, the AC high-voltage thyristor dimming system has relatively simple wiring, does not require additional signal lines, has good dimming consistency, can smoothly dim within 0-100%, and has strong lamp compatibility. It is particularly suitable for the livestock industry's high requirements for light adjustment standards.

[0003] Because the AC high-voltage thyristor dimming system and LED load are directly connected to the mains, they are susceptible to interference from mains equipment. The basic principle of lamp dimming is to collect the zero-point signal of the AC phase line and then further process it. However, when the power grid fluctuates, it is easy to cause zero-point drift and acquisition errors. The stability of the dimming system needs to be strengthened. Utility Model Content

[0004] In order to overcome the above technical problems existing in the prior art, the purpose of the present invention is to provide an LED high-voltage dimming control system to improve the stability of the dimming system and the smoothness and consistency of the dimming.

[0005] The utility model provides an LED high-voltage dimming control system, comprising:

[0006] System power supply module, providing stable power supply voltage for other circuit modules and units;

[0007] Phase zero-crossing detection circuit module detects the zero-crossing point of the AC power and transmits the zero-crossing point signal to the MCU single-chip control center unit;

[0008] The bidirectional thyristor drive circuit module has an output end connected to the LED lighting load and the external AC alternating current, and an input end that changes the conduction phase angle of the AC alternating current sinusoidal wave at the output end by receiving a pulse signal from the MCU control center unit;

[0009] AD conversion circuit module, performing analog-to-digital conversion;

[0010] The communication display module is connected to the MCU single-chip computer control center unit through the RS232 data line. The operator inputs the dimming value and other information on the communication display module and sends it to the MCU single-chip computer control center unit. After the MCU single-chip computer control center unit receives the dimming information, it implements the phase angle chopping execution instruction of the bidirectional thyristor drive circuit by changing the pulse sending time within each sine wave cycle.

[0011] LED lighting load, dimming is achieved by changing the conduction phase angle;

[0012] The MCU single chip control center unit can realize on-site manual dimming and remote dimming by receiving external signal 0-10V signal through the communication display module.

[0013] The system power supply module includes three circuits: the rectifier and filter circuit adopts a rectifier bridge and LC filter solution, the AC / DC step-down circuit adopts an LS05-13BxxR3 series switching power supply module solution, and the DC / DC step-down circuit adopts an LDO linear regulator solution.

[0014] The MCU single-chip control center unit is the hub of the entire system and adopts a 32-bit ARM microcontroller. The 32-bit ARM microcontroller core chip integrates peripherals including: multiple timers, high-speed communication interfaces and analog-to-digital converters.

[0015] The MCU single chip control center unit adopts the ARM Cortex-M3 core.

[0016] The communication display module adopts a liquid crystal screen with serial communication, and the liquid crystal screen adopts an RS232 driving receiving chip to communicate with the MCU single chip computer control center unit.

[0017] The phase zero-crossing detection circuit module includes a fuse F1, a rectifier bridge D1, seven resistors: resistors R1-R7, an LED red light D2, an optocoupler U1, and a transistor Q1. The input end of the optocoupler U1 is connected to the rectifier bridge D1 and the resistor R2, and the output end is connected to the LED red light D2, the resistor R5, the resistor R7, and the base of the transistor Q1. The zero-crossing signal is taken from the collector of the transistor Q1.

[0018] The bidirectional thyristor drive circuit module includes a bidirectional thyristor photoelectric drive coupler U2, a bidirectional thyristor Q3, seven resistors: R8-R14, a transistor Q2, three capacitors: C1-C3, a red light D3, an inductor L1, a surge suppression diode D4, and a varistor R15. The input end of the bidirectional thyristor photoelectric drive coupler U2 is connected to the red light D3 and the resistor R8, the output end of the bidirectional thyristor photoelectric drive coupler U2 is connected to the resistors R11, R13 and the trigger electrode of the bidirectional thyristor Q3, the T1 electrode of the bidirectional thyristor Q3 is connected to the resistor R13, the resistor R15, the capacitor C3, and the surge suppression diode D4, the T2 electrode of the bidirectional thyristor Q3 is connected to the resistor R12 and the inductor L1, and the LED lighting load is connected to the T2 and T2-N of the bidirectional thyristor Q3.

[0019] The AD conversion circuit module uses an LM358 operational amplifier to perform analog-to-digital conversion and then enters the MCU single-chip control center unit. The MCU single-chip control center unit outputs a dimming signal instruction according to the amplitude of the signal.

[0020] The LED lighting load is a lamp with a thyristor dimming chip driving a switching power supply, with a rated voltage of AC100-240V.

[0021] The utility model provides an LED high-voltage dimming control system with the beneficial effects of stepping down and stabilizing the system power supply module through a triple circuit system of a rectifier and filter circuit, an AC / DC step-down circuit, and a DC / DC step-down circuit C, thereby exhibiting excellent electromagnetic compatibility and stability against voltage fluctuations, thus providing reliable power supply for the system. The phase zero-crossing detection circuit module uses an optocoupler U1, and the bidirectional thyristor drive circuit module uses a bidirectional thyristor photoelectric drive coupler U2. Both optocouplers provide electrical isolation, preventing mutual interference between the primary and secondary circuits. The bidirectional thyristor drive circuit module uses an RC absorption protection design to limit the voltage rise of the thyristor, preventing the thyristor from erroneously turning on due to excessively rapid voltage rise. The inductor core inductance is rationally designed to optimize the system impedance, reducing chopping oscillation interference during turn-on, thereby enhancing stability. The MCU single-chip control center unit uses 32-bit ARM microcontroller pulse modulation dimming technology to achieve precise control of light brightness, making the LED lighting load dimming smoother, and allowing users to freely adjust the light brightness as needed to meet different usage scenarios and requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the utility model;

[0023] Figure 2 This is the connection diagram of the components of the bidirectional thyristor drive circuit module;

[0024] Figure 3 This is the connection diagram of the components of the phase zero-crossing detection circuit module;

[0025] Figure 4 This is the connection diagram between the communication display module and the MCU single chip computer control center unit;

[0026] Figure 5 It is the timing diagram of zero-crossing signal, pulse signal, and AC chopping waveform. DETAILED DESCRIPTION

[0027] The following describes in detail an LED high-voltage dimming control system provided by the present invention with reference to the accompanying drawings and in combination with an embodiment.

[0028] Example

[0029] Reference Figure 1-Figure 5 , an LED high-voltage dimming control system of this embodiment includes:

[0030] System power supply module, providing stable power supply voltage for other circuit modules and units;

[0031] Phase zero-crossing detection circuit module detects the zero-crossing point of the AC power and transmits the zero-crossing point signal to the MCU single-chip control center unit;

[0032] The bidirectional thyristor drive circuit module has an output end connected to the LED lighting load and the external AC alternating current, and an input end that changes the conduction phase angle of the AC alternating current sinusoidal wave at the output end by receiving a pulse signal from the MCU control center unit;

[0033] AD conversion circuit module, performing analog-to-digital conversion;

[0034] The communication display module is connected to the MCU single-chip computer control center unit through the RS232 data line. The operator inputs the dimming value and other information on the communication display module and sends it to the MCU single-chip computer control center unit. After the MCU single-chip computer control center unit receives the dimming information, it implements the phase angle chopping execution instruction of the bidirectional thyristor drive circuit by changing the pulse sending time within each sine wave cycle.

[0035] LED lighting load, dimming is achieved by changing the conduction phase angle;

[0036] The MCU single chip control center unit can realize on-site manual dimming and remote dimming by receiving external signal 0-10V signal through the communication display module.

[0037] The system power supply module includes three circuits: the rectifier and filter circuit adopts a rectifier bridge and LC filter solution, the AC / DC step-down circuit adopts an LS05-13BxxR3 series switching power supply module solution, and the DC / DC step-down circuit adopts an LDO linear regulator solution.

[0038] The MCU single-chip control center unit is the hub of the entire system and adopts a 32-bit ARM microcontroller. The 32-bit ARM microcontroller core chip integrates peripherals including: multiple timers, high-speed communication interfaces and analog-to-digital converters.

[0039] The MCU single chip control center unit adopts the ARM Cortex-M3 core.

[0040] The communication display module adopts a serial communication LCD screen, which uses an RS232 driver receiving chip to communicate with the MCU single-chip control center unit, and adopts a 7-inch medical-grade capacitive touch screen, RS232 standard interface, and Modbus protocol.

[0041] The phase zero-crossing detection circuit module includes a fuse F1, a rectifier bridge D1, seven resistors: resistors R1-R7, an LED red light D2, an optocoupler U1, and a transistor Q1. The input end of the optocoupler U1 is connected to the rectifier bridge D1 and the resistor R2, and the output end is connected to the LED red light D2, the resistor R5, the resistor R7, and the base of the transistor Q1. The zero-crossing signal is taken from the collector of the transistor Q1.

[0042] The bidirectional thyristor drive circuit module includes a bidirectional thyristor photoelectric drive coupler U2, a bidirectional thyristor Q3, seven resistors: R8-R14, a transistor Q2, three capacitors: C1-C3, a red light D3, an inductor L1, a surge suppression diode D4, and a varistor R15. The input end of the bidirectional thyristor photoelectric drive coupler U2 is connected to the red light D3 and the resistor R8, the output end of the bidirectional thyristor photoelectric drive coupler U2 is connected to the resistors R11, R13 and the trigger electrode of the bidirectional thyristor Q3, the T1 electrode of the bidirectional thyristor Q3 is connected to the resistor R13, the resistor R15, the capacitor C3, and the surge suppression diode D4, the T2 electrode of the bidirectional thyristor Q3 is connected to the resistor R12 and the inductor L1, and the LED lighting load is connected to the T2 and T2-N of the bidirectional thyristor Q3.

[0043] The AD conversion circuit module uses an LM358 operational amplifier to perform analog-to-digital conversion and then enters the MCU single-chip control center unit. The MCU single-chip control center unit outputs a dimming signal instruction according to the amplitude of the signal.

[0044] The LED lighting load is a lamp with a thyristor dimming chip driving a switching power supply, with a rated voltage of AC100-240V.

[0045] The LED dimming control system receives an external 0-10V signal from the signal input terminal and enters the AD conversion circuit module. After analog-to-digital conversion, it enters the MCU control center unit, which outputs a dimming signal instruction according to the amplitude of the signal.

[0046] After the zero-crossing signal of the phase zero-crossing detection circuit is taken out, it is amplified by the operational amplifier and then sent to the MCU single-chip control center unit. The MCU single-chip control center unit processes the received zero-crossing signal and outputs a pulse signal to the input end of the bidirectional thyristor drive circuit module.

[0047] The pulse output by the MCU control center unit is a square wave signal with a fixed frequency and period, T = 2-5us, and a frequency that is twice the AC frequency. For example, if the AC frequency is 50Hz, the square wave signal is 100Hz; if the AC frequency is 60Hz, the square wave signal is 120Hz, and so on, for the positive and negative waveforms of the AC. Depending on the dimming value, the time that the pulse signal lags behind the zero-crossing signal varies.

[0048] The bidirectional thyristor drive circuit module can be expanded into a multi-channel module, each module outputs one channel connected to the LED lighting load, and the output end of the bidirectional thyristor drive circuit module uses a forward-cutting chopping method for the AC positive wave.

[0049] The external AC power passes through the rectifier and filter circuits, the AC / DC step-down circuit, and the DC / DC step-down circuit, respectively, to power the MCU (microcontroller control center), the phase zero-crossing detection module, and the triac driver circuit module. The phase zero-crossing detection module receives the zero-crossing signal from the AC power filtering circuit and transmits it to the MCU as a 5V square wave. After receiving the zero-crossing signal, the MCU delays for a specified time (the specific delay time depends on the dimming value) and then sends a pulse signal. This pulse signal controls the triac driver circuit module to chop the AC power. The LED lighting load receives the chopped AC power and dims the LED. The external device sends a 0-10V analog signal, which undergoes A / D conversion and is then sent to the MCU. The MCU then sends a pulse signal based on this analog signal to control the triac driver circuit module, thereby achieving the external device's lighting control needs. The communication display module and the MCU single-chip control center unit transmit two-way signals, which can not only display the dimming status required by the external signal when an external 0-10V signal is applied, but also can adjust and display the control status in real time on site.

[0050] The utility model enhances the anti-interference ability and the stability of the thyristor drive circuit through the optimized design; and ensures the fineness of dimming through the precise program delay calculation of the MCU output pulse, making the LED lighting load dimming smoother.

Claims

1. An LED high voltage dimming control system, characterized in that: include: System power supply module, providing stable power supply voltage for other circuit modules and units; Phase zero-crossing detection circuit module detects the zero-crossing point of the AC power and transmits the zero-crossing point signal to the MCU single-chip control center unit; The bidirectional thyristor drive circuit module has an output end connected to the LED lighting load and the external AC alternating current, and an input end that changes the conduction phase angle of the AC alternating current sinusoidal wave at the output end by receiving a pulse signal from the MCU control center unit; AD conversion circuit module, performing analog-to-digital conversion; The communication display module is connected to the MCU single-chip computer control center unit via an RS232 data line. The operator inputs the dimming value information on the communication display module and sends it to the MCU single-chip computer control center unit. After receiving the dimming information, the MCU single-chip computer control center unit implements the phase angle chopping execution instruction of the bidirectional thyristor drive circuit by changing the pulse sending time within each sine wave cycle; LED lighting load, dimming is achieved by changing the conduction phase angle; The MCU single chip control center unit can realize on-site manual dimming and remote dimming by receiving external signal 0-10V signal through the communication display module.

2. The LED high-voltage dimming control system according to claim 1, characterized in that: The system power supply module includes three circuits: the rectifier and filter circuit adopts a rectifier bridge and LC filter solution, the AC / DC step-down circuit adopts an LS05-13BxxR3 series switching power supply module solution, and the DC / DC step-down circuit adopts an LDO linear regulator solution.

3. The LED high-voltage dimming control system according to claim 1, characterized in that: The MCU single-chip control center unit is the hub of the entire system and adopts a 32-bit ARM microcontroller. The 32-bit ARM microcontroller core chip integrates peripherals including: multiple timers, high-speed communication interfaces and analog-to-digital converters.

4. The LED high-voltage dimming control system according to claim 3, characterized in that: The MCU single chip control center unit adopts the ARM Cortex-M3 core.

5. The LED high-voltage dimming control system according to claim 1, characterized in that: The communication display module adopts a liquid crystal screen with serial communication, and the liquid crystal screen adopts an RS232 driving receiving chip to communicate with the MCU single chip computer control center unit.

6. The LED high-voltage dimming control system according to claim 1, characterized in that: The phase zero-crossing detection circuit module includes a fuse F1, a rectifier bridge D1, seven resistors: resistors R1-R7, an LED red light D2, an optocoupler U1, and a transistor Q1. The input end of the optocoupler U1 is connected to the rectifier bridge D1 and the resistor R2, and the output end is connected to the LED red light D2, the resistor R5, the resistor R7, and the base of the transistor Q1. The zero-crossing signal is taken from the collector of the transistor Q1.

7. The LED high-voltage dimming control system according to claim 1, characterized in that: The bidirectional thyristor drive circuit module includes a bidirectional thyristor photoelectric drive coupler U2, a bidirectional thyristor Q3, seven resistors: R8-R14, a transistor Q2, three capacitors: C1-C3, a red light D3, an inductor L1, a surge suppression diode D4, and a varistor R15. The input end of the bidirectional thyristor photoelectric drive coupler U2 is connected to the red light D3 and the resistor R8, the output end of the bidirectional thyristor photoelectric drive coupler U2 is connected to the resistors R11, R13 and the trigger electrode of the bidirectional thyristor Q3, the T1 electrode of the bidirectional thyristor Q3 is connected to the resistor R13, the resistor R15, the capacitor C3, and the surge suppression diode D4, the T2 electrode of the bidirectional thyristor Q3 is connected to the resistor R12 and the inductor L1, and the LED lighting load is connected to the T2 and T2-N of the bidirectional thyristor Q3.

8. The LED high-voltage dimming control system according to claim 1, characterized in that: The AD conversion circuit module uses an LM358 operational amplifier to perform analog-to-digital conversion and then enters the MCU single-chip control center unit. The MCU single-chip control center unit outputs a dimming signal instruction according to the amplitude of the signal.

9. The LED high-voltage dimming control system according to claim 1, characterized in that: The LED lighting load is a lamp with a thyristor dimming chip driving a switching power supply, with a rated voltage of AC100-240V.

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