Digital apron marker light power supply and control method

Abstract

The application relates to a digital apron marker light power supply and a control method. When a dimmer is adjusted from low to high, the boost circuit adjustment bandwidth is effectively improved, so that the apron marker light brightness is constant when the dimmer shifts gears, the isolation transformer has a desaturation function when saturated, the saturation of the isolation transformer is effectively avoided, the regulator is accelerated to stabilize, the light brightness stability is ensured, and the normal lighting effect of the apron marker light is ensured.

Description

Technical Field

[0001] This invention relates to the field of apron sign lighting control technology, and in particular to a digital apron sign lighting power supply and control method. Background Technology

[0002] The lights on apron markers are generally powered by a constant current dimmer cabinet, which is connected to an isolation transformer. The secondary winding of the isolation transformer is connected to the lighting circuit. The transformer has a power limit. When the power limit is reached, the transformer enters a saturation state and there is no output. This design is to ensure that the normal operation of the dimmer is not affected when the load and voltage of the lighting circuit change or when there is a fault.

[0003] Constant current dimmers have multiple dimming levels, each with a different output current. The brightness of apron marking signs needs to be constant at different dimming levels, which requires a specific power supply device to ensure stable power supply voltage and power.

[0004] Typical signage lighting circuits use a boost converter connected to LEDs. When the dimmer switches from a low to a high setting, the dimmer's output current increases. At this time, it's crucial to maintain a constant output voltage and power consumption on the LEDs, while ensuring the transformer doesn't saturate. If the boost duty cycle remains constant, the transformer's power and voltage will surge instantaneously, leading to saturation and loss of output capacity, causing the LEDs to lose power. Therefore, when switching dimmers from low to high, the boost duty cycle must increase rapidly to quickly reduce the transformer's secondary voltage; otherwise, the light brightness will change. Furthermore, if the transformer is already close to saturation and its output capacity is decreasing, continuing to increase the duty cycle will create positive feedback, further damaging the transformer and causing the LEDs to turn off irreversibly. Therefore, traditional boost control methods are no longer suitable when the transformer is nearing saturation.

[0005] Due to the bandwidth limitations of traditional boost circuits, when adjusting the constant current dimmer on the apron from low to high settings, especially when crossing multiple settings, the control circuit may not adjust in time, causing the isolation transformer to saturate and lose its output capacity. Furthermore, when the transformer approaches saturation, the adjustment becomes positive feedback, ultimately causing the transformer to collapse and unable to recover from saturation. At this point, the lighting will go out and cannot be restored. Summary of the Invention

[0006] This invention addresses the technical problems existing in the prior art by providing a digital apron marker light power supply and control method.

[0007] To solve the above-mentioned technical problems, in a first aspect, embodiments of the present invention provide a digital apron sign light power supply, a rectifier, a single-chip microcomputer (MCU), and a boost circuit;

[0008] The rectifier is used to convert the input AC signal into a DC signal;

[0009] The microcontroller (MCU) is used to determine the feedforward regulation coefficient based on the steady-state input voltage and the actual input voltage; to determine the anti-saturation regulation coefficient based on the output voltage and the minimum voltage threshold, wherein the output voltage is the voltage output to the light source; and to determine the pulse width modulation (PWM) duty cycle based on the feedforward regulation coefficient, the anti-saturation regulation coefficient, and the PI controller.

[0010] The boost circuit is used to increase the voltage based on the PWM duty cycle, and the output is connected to a light source.

[0011] Preferably, the rectifier is connected to an isolation transformer, and the isolation transformer is connected to a dimmer.

[0012] Preferably, the microcontroller (MCU) includes a feedforward module, an anti-saturation module, a PI regulator, a first analog-to-digital converter (ADC), and a second ADC.

[0013] The first analog-to-digital converter is used to acquire the input voltage and convert it into a digital quantity;

[0014] The second analog-to-digital converter is used to acquire the voltage on the light source and convert it into a digital quantity;

[0015] The feedforward module is used to determine the feedforward adjustment coefficient K1 = m1*(Vr1-Vin) based on the steady-state input voltage and the actual input voltage, where m1 is the first adjustment coefficient, Vr1 is the steady-state input voltage collected when the circuit is operating in steady state, and Vin is the actual input voltage.

[0016] The anti-saturation module is used to determine the anti-saturation adjustment coefficient K2 = m2 * Vout / Vp based on the output voltage and the minimum voltage threshold, where m2 is the second adjustment coefficient, Vout is the output voltage to the light source, and Vp is the minimum voltage threshold.

[0017] The PI regulator is used to determine the PWM duty cycle Df = (D + K1) * K2, where D is the PWM duty cycle when the circuit is in steady state.

[0018] Preferably, when the dimmer setting remains unchanged, k1 = 0 and k2 = 1.

[0019] Secondly, embodiments of the present invention provide a control method for the power supply of a digital apron marker light according to a first aspect embodiment of the present invention, comprising:

[0020] If the dimmer is working stably, the input voltage Vin and the output voltage Vout remain stable, the feedforward regulation coefficient K1 is 0, the anti-saturation regulation coefficient K2 is 1, and the PWM duty cycle is determined based on the PI regulator.

[0021] If the dimmer is upgraded and the input voltage Vin increases, the feedforward module takes effect, the feedforward adjustment coefficient K1 increases, the anti-saturation module takes effect, and the anti-saturation adjustment coefficient K2 remains unchanged; the output duty cycle Df increases at a faster rate to make the output voltage stabilize more quickly.

[0022] If the dimmer is upgraded and the input voltage Vin decreases, the feedforward module takes effect, the feedforward adjustment coefficient K1 decreases, the anti-saturation module takes effect, the anti-saturation adjustment coefficient K2 decreases or remains unchanged, so as to reduce the output duty cycle Df.

[0023] Preferably, the anti-saturation adjustment coefficient K2 is reduced or kept constant to reduce the output duty cycle Df, specifically including:

[0024] If it is determined that the output voltage Vout has not dropped below the minimum voltage threshold, the feedforward regulation coefficient K1 decreases, the anti-saturation regulation coefficient K2 remains unchanged, the PWM duty cycle decreases, and the isolation transformer desaturates.

[0025] Preferably, the anti-saturation adjustment coefficient K2 is reduced or kept constant to reduce the output duty cycle Df, and the method further includes:

[0026] If the output voltage Vout drops below the minimum voltage threshold, the feedforward regulation coefficient K1 decreases, the anti-saturation regulation coefficient K2 decreases, the PWM duty cycle decreases more rapidly, and the isolation transformer desaturates faster.

[0027] Thirdly, embodiments of the present invention provide a digital apron sign lighting device, including a digital apron sign lighting power supply as described in the first aspect of the present invention, and an LED light connected to the digital apron sign lighting power supply.

[0028] The beneficial effects of this invention are: when the dimmer is adjusted from low to high, it effectively increases the adjustment bandwidth of the boost circuit, thereby ensuring that the brightness of the apron sign light remains constant when the dimmer is switched, and it also has a desaturation function when the transformer is saturated, effectively avoiding the saturation of the isolation transformer, accelerating the stabilization of the regulator, ensuring the stability of the light brightness, and ensuring the normal lighting effect of the apron sign light. Attached Figure Description

[0029] Figure 1 This is a block diagram of a digital apron marker light power supply structure according to an embodiment of the present invention;

[0030] Figure 2 This is a circuit diagram of a digital apron marker light power supply structure according to an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of a single-chip microcontroller (MCU) according to an embodiment of the present invention;

[0032] Figure 4 This is a flowchart of the control method according to an embodiment of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, not all 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.

[0034] Due to the bandwidth limitations of traditional boost circuits, when adjusting the constant current dimmer on the apron from low to high settings, especially when crossing multiple settings, the control circuit may not adjust in time, causing the isolation transformer to saturate and lose its output capacity. Furthermore, when the transformer approaches saturation, the adjustment becomes positive feedback, ultimately causing the transformer to collapse and unable to recover from saturation. At this point, the lighting will go out and cannot be restored.

[0035] Therefore, embodiments of the present invention provide a digital apron sign light power supply and control method, which effectively improves the adjustment bandwidth of the boost circuit when the dimmer is adjusted from low to high, thereby ensuring that the brightness of the apron sign light remains constant when the dimmer is switched, and also provides a desaturation function when the transformer is saturated. The following will elaborate and describe this through several embodiments.

[0036] Figure 1 This invention provides a digital apron marker light power supply, including a rectifier, a microcontroller (MCU), and a boost circuit;

[0037] The rectifier is connected to the isolation transformer, and the isolation transformer is connected to the dimmer. The dimmer is used to change the effective value of the current of the input light source by adjusting the voltage range, and the rectifier is used to convert the AC signal of the isolation transformer into a DC signal.

[0038] The microcontroller (MCU) is used to determine the feedforward regulation coefficient based on the steady-state input voltage and the actual input voltage; to determine the anti-saturation regulation coefficient based on the output voltage and the minimum voltage threshold, wherein the output voltage is the voltage output to the light source; and to determine the pulse width modulation (PWM) duty cycle based on the feedforward regulation coefficient, the anti-saturation regulation coefficient, and the PI controller.

[0039] Specifically, in this embodiment, the microcontroller MCU is a digital main control chip, including a feedforward module, an anti-saturation module, a PI regulator, a first analog-to-digital converter AD1, and a second analog-to-digital converter AD2;

[0040] The first analog-to-digital converter AD1 is used to acquire the input voltage of the isolation transformer and convert it into a digital quantity for subsequent calculations;

[0041] The second analog-to-digital converter AD2 is used to acquire the voltage on the light source and convert it into a digital quantity for subsequent calculations;

[0042] Vr2 is the target voltage controlled on the LED. After the microcontroller (MCU) acquires the output Vout, it uses the PI algorithm on the MCU, combined with the feedforward module and anti-saturation strategy, to adjust the PWM duty cycle of the output circuit, ensuring that the LED voltage is constant and the brightness of the light is stable.

[0043] The feedforward module is used to increase the control bandwidth to ensure the speed of the entire circuit adjustment during gear switching, and the brightness of the light does not change during gear switching. The inputs of the feedforward module are Vr1 and Vin, where Vr1 is the input voltage collected when the circuit is in steady state, and the output of the feedforward module is the feedforward adjustment coefficient K1 = m1 * (Vr1 - Vin), where m1 is the first adjustment coefficient, Vr1 is the steady-state input voltage collected when the circuit is in steady state, and Vin is the actual input voltage.

[0044] The anti-saturation module ensures that the transformer can exit saturation in a timely manner when it approaches or enters saturation, preventing it from losing output capacity and causing the entire circuit to shut down. The input to the anti-saturation module is the minimum voltage threshold Vp. When the output voltage is lower than the minimum voltage threshold Vp, it indicates that the transformer's input power is insufficient, and the isolation transformer is saturated. At this point, the anti-saturation strategy takes effect. The output of the anti-saturation module is the anti-saturation adjustment coefficient K2 = m2 * Vout / Vp, where m2 is the second adjustment coefficient, Vout is the output voltage to the light source, and Vp is the minimum voltage threshold to the light source. When the dimmer setting remains unchanged, k1 = 0 and k2 = 1.

[0045] The PI regulator is used to determine the PWM duty cycle Df = (D + K1) * K2, where D is the PWM duty cycle when the circuit is in steady state.

[0046] The boost circuit is used to increase the voltage based on the PWM duty cycle, and the output is connected to a light source, which is an LED lamp in this embodiment.

[0047] like Figure 2 As shown, D1 is the rectifier bridge, MOSFET Q1, inductor L1, and diode D2 form a boost circuit, and PWM1 output controls the boost ratio.

[0048] Figure 3 The microcontroller (MCU) samples VOUT and VIN respectively using an AD converter. After sampling, the MCU performs calculations and outputs PWM1 to drive the MOSFET Q1, thus enabling the operation of the entire system.

[0049] This invention provides a control method for the power supply of a digital apron marker light according to the above embodiments of the present invention, such as... Figure 4 As shown, it includes:

[0050] If the dimmer is working stably, the input voltage Vin and the output voltage Vout remain stable, the feedforward regulation coefficient K1 is 0, and the anti-saturation regulation coefficient K2 is 1. At this time, the feedforward and anti-saturation modules are not effective, and the loop output is determined by the PI regulator.

[0051] If the dimmer is upgraded and the input voltage Vin increases, it indicates that the isolation transformer is working normally. In this case, the feedforward module is activated, the feedforward regulation coefficient K1 increases, the anti-saturation module is deactivated, and the anti-saturation regulation coefficient K2 remains unchanged. The output duty cycle Df increases at a faster rate to stabilize the output voltage more quickly.

[0052] If the dimmer increases in speed and the input voltage Vin decreases, it indicates that the isolation transformer has begun to enter saturation. In this case, the feedforward module activates, decreasing the feedforward adjustment coefficient K1. The anti-saturation module also activates, decreasing or keeping the anti-saturation adjustment coefficient K2, thus reducing the output duty cycle Df. Specifically:

[0053] If the output voltage Vout drops below the minimum voltage threshold, it means that the input voltage Vin still has output capability. At this time, the feedforward regulation coefficient K1 decreases, the anti-saturation regulation coefficient K2 remains unchanged, the feedforward module still takes effect, the PWM duty cycle decreases, and the isolation transformer desaturates.

[0054] If the output voltage Vout drops below the minimum voltage threshold, it indicates that the transformer is saturated. At this time, the feedforward module and the anti-saturation module work together. The feedforward adjustment coefficient K1 decreases, the anti-saturation adjustment coefficient K2 decreases, the PWM duty cycle decreases more rapidly, and the isolation transformer desaturates faster.

[0055] This ensures that the entire control system can quickly and stably maintain LED brightness when the dimmer switches gears, while also preventing the isolation transformer from saturating during the gear-up process.

[0056] This invention also provides a digital apron sign lighting device, including a digital apron sign lighting power supply as described in the above embodiments of this invention, and an LED light connected to the digital apron sign lighting power supply.

[0057] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0058] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0059] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0060] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0061] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0062] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0063] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A digital airfield marker light power supply, characterized in that, This includes a rectifier, a microcontroller (MCU), and a boost circuit. The rectifier is used to convert the input AC signal into a DC signal; The microcontroller (MCU) is used to determine the feedforward regulation coefficient based on the steady-state input voltage and the actual input voltage; and to determine the anti-saturation regulation coefficient based on the output voltage and the minimum voltage threshold, wherein the output voltage is the voltage output to the light source. The pulse width modulation (PWM) duty cycle is determined based on the feedforward adjustment coefficient, the anti-saturation adjustment coefficient, and the PI regulator. The boost circuit is used to increase the voltage based on the PWM duty cycle, and the output is connected to a light source. The rectifier is connected to an isolation transformer, and the isolation transformer is connected to a dimmer. The microcontroller (MCU) includes a feedforward module, an anti-saturation module, a PI regulator, a first analog-to-digital converter (ADC), and a second ADC. The first analog-to-digital converter is used to acquire the input voltage and convert it into a digital quantity; The second analog-to-digital converter is used to acquire the voltage on the light source and convert it into a digital quantity; The feedforward module is used for determining a feedforward adjustment coefficient K1=m1 based on a steady input voltage and an actual input voltage (Vr1-Vin), wherein m1 is a first adjustment coefficient, Vr1 is a steady input voltage collected when the circuit works in a steady state, and Vin is an actual input voltage. The anti-saturation module is configured to determine an anti-saturation regulation coefficient K2 = m2 based on an output voltage and a minimum voltage threshold Vout / Vp, where m2 is a second regulation coefficient, Vout is an output voltage output to the light source, and Vp is a minimum voltage threshold output to the light source; The PI regulator is used to determine the PWM duty cycle Df = (D + K1) K2, where D is the PWM duty cycle when the circuit is operating in steady state.

2. A digital apron marker light power supply as claimed in claim 1, characterised in that, When the dimmer setting remains unchanged, K1=0 and K2=1.

3. A method of controlling a power supply for a digital apron marker light according to any one of claims 1 to 2, characterized in that, include: If the dimmer is working stably, the input voltage Vin and the output voltage Vout remain stable, the feedforward regulation coefficient K1 is 0, the anti-saturation regulation coefficient K2 is 1, and the PWM duty cycle is determined based on the PI regulator. If the dimmer is upgraded and the input voltage Vin increases, the feedforward module will take effect and the feedforward adjustment coefficient K1 will increase. The anti-saturation module will not take effect and the anti-saturation adjustment coefficient K2 will remain unchanged. The output duty cycle Df increases at a faster rate, so that the output voltage stabilizes more quickly; If the dimmer is increased and the input voltage Vin decreases, the feedforward module takes effect, the feedforward adjustment coefficient K1 decreases, the anti-saturation module takes effect, the anti-saturation adjustment coefficient K2 decreases or remains unchanged, so as to reduce the output duty cycle Df.

4. The method of claim 3, wherein the method further comprises: The anti-saturation adjustment coefficient K2 is either decreased or kept constant to reduce the output duty cycle Df, specifically including: If it is determined that the output voltage Vout has not dropped below the minimum voltage threshold, the feedforward regulation coefficient K1 decreases, the anti-saturation regulation coefficient K2 remains unchanged, the PWM duty cycle decreases, and the isolation transformer desaturates.

5. The method of claim 3, wherein the method further comprises: The anti-saturation adjustment coefficient K2 is either decreased or kept constant to reduce the output duty cycle Df, and this also includes: If the output voltage Vout drops below the minimum voltage threshold, the feedforward regulation coefficient K1 decreases, the anti-saturation regulation coefficient K2 decreases, the PWM duty cycle decreases more rapidly, and the isolation transformer desaturates faster.

6. A digital airfield marker light device, characterized by It includes the digital apron sign light power supply as described in any one of claims 1 to 2, and an LED light connected to the digital apron sign light power supply.

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