LED dimming control system

Abstract

The utility model discloses an LED dimming control system which comprises a power supply driving module, an MCU single-chip microcomputer control center unit, a communication display and interaction module, a clock module, a program storage module, an ADC analog-to-digital conversion module, a DAC digital-to-analog conversion module, an LED illumination driving power supply output chopping control module, an LED illumination driving power supply and an LED light source. According to the functions of the LED lamp, the intensity of the LED lamp can be adjusted on site, a time-sharing regulation and control strategy can be set, and dimming can be achieved by receiving external 0-10 V dimming signals.

Description

Technical Field

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

[0002] In the current application of LED lighting fixtures, there are two driving modes for LED light sources, one is constant current driving and the other is constant voltage driving. Constant current driving is generally only used to drive one group of light sources. When driving multiple groups of light sources at the same time, it is difficult for the current of each light source to remain basically the same. Therefore, constant voltage driving is often used when driving multiple groups of light sources. Constant voltage driving also has its own disadvantages. For example, in aquaculture lighting, because the aquaculture environment is humid and the lamps are hung low, for the safety of human body and electricity, low-voltage lighting is generally used, and each light source is more and the line is longer. With the increase of light sources and the extension of the line, a large voltage drop will be generated on the line, making the brightness of the front and rear lamps inconsistent, the lighting uniformity is not good, and the lighting effect is not ideal. In order to maintain a high degree of consistency in the brightness of the front and rear, the light source needs to overcome the influence of the voltage drop. When the front and rear power supply voltages are different due to the line voltage drop problem, the light source can still maintain the same brightness. Therefore, the design of constant current chips is often used. After the constant current chip solution is adopted, the dimming mode will change. The scheme of voltage adjustment or increasing the dimming line cannot be implemented due to principle or cost issues. Utility Model Content

[0003] In order to overcome the above technical problems existing in the prior art, the purpose of the utility model is to provide an LED dimming control system, which can dim the LED low-voltage linear constant current light source.

[0004] The LED dimming control system provided by the utility model includes:

[0005] The power driver module is used to supply power to the MCU control center unit and other peripheral function chips;

[0006] The MCU single-chip control center unit is the hub of the entire system, used to receive external control signals and issue dimming commands. It uses 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;

[0007] Communication display and interaction module, which displays and adjusts the lighting intensity in real time through the display screen;

[0008] The clock module and the program storage module cooperate with the energy storage battery to provide uninterrupted clock and program storage for the communication display and interaction module;

[0009] The ADC analog-to-digital conversion module and the DAC digital-to-analog conversion module receive dimming commands from external devices and convert the primary dimming input signal of the LED lighting driver power supply to provide a primary dimming signal for the LED light source;

[0010] The LED lighting driver power supply output chopper control module adjusts the duty cycle output of the LED lighting driver power supply, changes the output average voltage of the LED lighting driver power supply, and realizes secondary dimming of the LED light source;

[0011] LED lighting driver power supply and LED light source.

[0012] The power drive module includes a rectifier filter EMI circuit, an AC / DC circuit, and a DC / DC circuit which are connected in sequence.

[0013] The MCU single-chip control center unit adopts the ARM Cortex-M3 core.

[0014] The communication display and interaction module adopts a liquid crystal screen with serial communication, and the liquid crystal screen adopts an RS232 drive receiving chip to communicate with the MCU single-chip control center unit.

[0015] The clock module adopts an industrial-grade clock and calendar chip with an I2C bus interface function, and the program storage module adopts an electrically erasable programmable read-only memory EEPROM, which is controlled by the I2C bus and uses a two-wire serial interface of a bidirectional data bus and a serial clock.

[0016] The LED lighting driving power supply is a transformer with an input rated voltage of 100-240V AC and an output of 48V DC.

[0017] The LED lighting driving power supply output chopping control module is connected in series with a MOS tube on the negative side of the LED lighting driving power supply output, and the dimming signal output by the control MCU single-chip control center unit is loaded on the gate of the MOS tube after conversion processing, so as to change the duty cycle of the gate voltage, control the opening and closing of the MOS tube to realize the conduction of the negative electrode of the LED lighting driving power supply, thereby changing the size of the output voltage of the LED lighting driving power supply, and giving the output voltage to the LED light source, thereby performing secondary adjustment on the brightness of the LED light source.

[0018] The LED light source is a low-voltage linear constant-current LED light source with a constant-current chip.

[0019] The LED dimming control system provided by the utility model has the beneficial effect that the signal input end of the LED driving power supply is adjusted once through the ADC analog-to-digital conversion module, the MCU single-chip control center unit, the DAC analog-to-digital conversion module and the LED lighting driving power supply output chopping module to change the LED output voltage; the output end of the LED driving power supply is chopped for secondary adjustment, and finally the intensity of the LED light source is effectively controlled, so that the light source is more stable from 0-100% dimming; the LED light source adopts a linear constant current solution, which avoids the brightness change of the lamp caused by the extension of the line when there are multiple light sources, so that the illumination of the entire lighting line is very uniform. The dimming system can not only adjust the intensity of the LED lamp on the spot and set the time-sharing control strategy, but also dim by accepting an external 0-10V dimming signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the overall structural diagram of the LED dimming control system;

[0021] Figure 2 This is a schematic diagram of the working process of the power drive module;

[0022] Figure 3 It is a schematic diagram of the communication signal transmission process of the communication display and interaction module;

[0023] Figure 4 This is a schematic diagram of a dimming process;

[0024] Figure 5 It is a schematic diagram of the secondary dimming process; DETAILED DESCRIPTION

[0025] The LED dimming control system provided by the present invention is described in detail below in conjunction with an embodiment with reference to the accompanying drawings.

[0026] Example

[0027] Reference Figure 1-5 , the LED dimming control system of this embodiment includes:

[0028] The power driver module is used to supply power to the MCU control center unit and other peripheral function chips;

[0029] The MCU single-chip control center unit is the hub of the entire system. It uses 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;

[0030] The communication display and interaction module is used to communicate with the receiving chip and the MCU single-chip control center unit, and to display and adjust the lighting intensity in real time through the display screen;

[0031] The clock module and the program storage module cooperate with the energy storage battery to provide uninterrupted clock and program storage for the communication display and interaction module;

[0032] The ADC analog-to-digital conversion module and the DAC digital-to-analog conversion module receive dimming commands from external devices and convert the primary dimming input signal of the LED lighting driver power supply to provide a primary dimming signal for the LED light source;

[0033] The LED lighting driver power supply output chopper control module adjusts the duty cycle output of the LED lighting driver power supply, changes the output average voltage of the LED lighting driver power supply, and realizes secondary dimming of the LED light source;

[0034] LED lighting driver power supply and LED light source.

[0035] The power drive module includes a rectifier filter EMI circuit, an AC / DC circuit, and a DC / DC circuit which are connected in sequence.

[0036] The MCU single-chip control center unit adopts the ARM Cortex-M3 core, which has high performance, low power consumption, strong versatility and scalability. The chip integrates various peripherals, including multiple timers, high-speed communication interfaces and analog-to-digital converters, etc., which can meet various application requirements.

[0037] The communication display and interaction 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.

[0038] The clock module can provide a clock for the communication display and interaction module, and adopts an industrial-grade multifunctional clock and calendar chip with extremely low power consumption and an I2C bus interface function. The program storage module adopts an electrically erasable programmable read-only memory EEPROM, which is controlled by the I2C bus and uses a two-wire serial interface of a bidirectional data bus and a serial clock.

[0039] The program storage module is specifically used to store dimming instructions.

[0040] The LED dimming control system signal input end receives an external 0-10V signal and enters the ADC analog-to-digital conversion module. After analog-to-digital conversion, it enters the MCU single-chip control center unit, which outputs a dimming signal instruction according to the size of the signal.

[0041] After the MCU single-chip control center unit outputs the dimming signal instruction, the dimming signal enters the DAC digital-to-analog conversion module, and the signal after digital-to-analog conversion enters the signal input end of the LED lighting driver power supply. The LED lighting driver power supply adjusts the output voltage according to this signal and gives the voltage to the LED light source, thereby preliminarily adjusting the brightness of the LED light source.

[0042] The LED lighting driving power supply is a transformer with an input rated voltage of 100-240V AC and an output of 48V DC.

[0043] The LED lighting driving power supply output chopping control module is connected in series with a MOS tube on the negative side of the LED lighting driving power supply output, and the dimming signal output by the control MCU single-chip control center unit is loaded on the gate of the MOS tube after conversion processing, so as to change the duty cycle of the gate voltage, control the opening and closing of the MOS tube to realize the conduction of the negative electrode of the LED lighting driving power supply, thereby changing the size of the output voltage of the LED lighting driving power supply, and giving the output voltage to the LED light source, thereby performing secondary adjustment on the brightness of the LED light source.

[0044] The LED light source is a low-voltage linear constant-current LED light source with a constant-current chip.

[0045] Specifically, Figure 1 As shown, the MCU single-chip control center unit is the center of the whole system. The external 0-10V dimming signal is converted by the ADC analog-to-digital conversion module and then transmitted to the MCU single-chip control center unit. The MCU single-chip control center unit then transmits the dimming instruction to the DAC analog-to-digital conversion module and the LED lighting driver power output chopping module. The DAC digital-to-analog conversion module converts the signal into an analog signal and transmits it to the signal input port of the LED lighting driver power supply to realize the primary dimming. The LED lighting driver power output chopping module transmits the signal to the output end of the LED lighting driver power supply, and chop the output end to realize the secondary dimming. After the power driver module receives AC220V power supply, it converts the AC220V AC voltage into the DC voltage required by each module. The communication display and interaction module and the MCU single-chip control center unit have two-way signal transmission, which can not only display the dimming state required by the external signal when the external 0-10V signal acts, but also can adjust and display the adjustment state in real time on site. The program storage module and the clock module provide uninterrupted clock power-off memory function.

[0046] like Figure 2 As shown, the power drive module obtains a primary voltage after AC / DC and DC / DC conversion through a rectifier and filter circuit, obtains a secondary voltage after processing by a BUCK circuit, and obtains a DC3.3-5V voltage after processing by a linear step-down chip.

[0047] like Figure 3 As shown, the communication display and interactive module communication signal is RS232, and the signal is transmitted through the RS232 transceiver drive circuit and the MCU microcontroller control center unit.

[0048] like Figure 4 As shown, the MCU single-chip control center unit outputs a digital signal which is converted into a 0-10V dimming signal through an integration circuit and an op amp circuit and then transmitted to the LED driving power supply for a dimming operation.

[0049] like Figure 5 As shown, the MCU single-chip control center unit outputs a digital signal that is converted into a gate drive signal through the MOS tube gate drive circuit to drive the MOS tube switch. The MOS tube D pole is connected to the positive pole of the LED light source, and the S pole is connected to the negative pole of the LED light source. The LED light source is composed of an LED constant current driver chip and an LED lamp bead in series.

Claims

1. An LED dimming control system, characterized in that: include: The power driver module is used to supply power to the MCU control center unit and other peripheral function chips; MCU single-chip control center unit, used to receive external control signals and issue dimming instructions; Communication display and interaction module, used to display and adjust lighting intensity in real time through the display screen; The clock module and the program storage module cooperate with the energy storage battery to provide uninterrupted clock and program storage for the communication display and interaction module; The ADC analog-to-digital conversion module and the DAC digital-to-analog conversion module receive dimming commands from external devices and convert the primary dimming input signal of the LED lighting driver power supply to provide a primary dimming signal for the LED light source; The LED lighting driver power supply output chopper control module adjusts the duty cycle output of the LED lighting driver power supply, changes the output average voltage of the LED lighting driver power supply, and realizes secondary dimming of the LED light source; LED lighting driver power supply and LED light source.

2. The LED dimming control system according to claim 1, characterized in that: The power drive module includes a rectifier filter EMI circuit, an AC / DC circuit, and a DC / DC circuit which are connected in sequence.

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

6. The LED dimming control system according to claim 1, characterized in that: The clock module adopts an industrial-grade clock and calendar chip with an I2C bus interface function, and the program storage module adopts an electrically erasable programmable read-only memory EEPROM, which is controlled by the I2C bus and uses a two-wire serial interface of a bidirectional data bus and a serial clock.

7. The LED dimming control system according to claim 1, characterized in that: The LED lighting driving power supply is a transformer with an input rated voltage of 100-240V AC and an output of 48V DC.

8. The LED dimming control system according to claim 1, characterized in that: The LED lighting driving power supply output chopping control module is connected in series with a MOS tube on the negative side of the LED lighting driving power supply output, and controls the dimming signal output by the MCU single-chip control center unit, which is loaded on the gate of the MOS tube after conversion processing, changes the duty cycle of the gate voltage, controls the opening and closing of the MOS tube to realize the conduction of the negative electrode of the LED lighting driving power supply, thereby changing the output voltage of the LED lighting driving power supply, and giving the output voltage to the LED light source, thereby performing secondary adjustment on the brightness of the LED light source.

9. The LED dimming control system according to claim 1, characterized in that: The LED light source is a low-voltage linear constant-current LED light source with a constant-current chip.

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