CN117580212B - Dimming lamp control method with smooth dark part - Google Patents

Abstract

The application discloses a dimming lamp control method with smooth dark part, which comprises the following steps: receiving dimming parameter input data; outputting a PWM dimming signal based on the dimming parameter input data; receiving a current acquisition signal, wherein the current acquisition signal characterizes real-time output current of the constant current device; and controlling the resistance of the balancing device based on the current acquisition signal so as to keep the load voltage of the constant current device unchanged, wherein the balancing device is connected in series with the light source which is dimmed, the balancing device and the light source which is dimmed form a load unit together, and the load unit is connected in series with the constant current device. The dimming lamp control method for smooth dimming of the dark part balances voltage of a load unit of a constant current device load, dynamically compensates and adjusts nonlinear current accurately, enables current flowing through a dimmed light source to change linearly, enables light source brightness to smoothly and stably transition in the dimming process of the dark part, and avoids dimming jitter in the dimming process of the dark part.

Description

Smooth dimming lamp control method

Technical Field

The present application relates to the technical field of lamp dimming, and in particular to a method for controlling a dimming lamp with smooth dimming.

Background technique

The human eye is more sensitive to changes in light in a dark environment. For example, in a dark environment, you can see the slight changes in the fluorescent flashes of fireflies. The human eye is more numb to changes in light in a bright light environment. For example, under the scorching sun, you cannot see the difference in brightness between lighting one candle and lighting two candles.

In the dimming process of existing lamps, the lights will experience dimming flicker and dimming jitter, which is more obvious when the brightness of the lamp is relatively low. The phenomenon of uneven flickering of lights during the dimming process can be called dimming flicker, and the phenomenon of uneven jittering of lights during the dimming process can be called dimming jitter. For example, in the application scenario of a show performance, during the dimming process of the lamp, within a certain period of time, for example, within 30 seconds, the brightness of the lamp is slowly and uniformly adjusted from dark to bright or from bright to dark. When dimming in the dark part, the observer can feel that the light is jittering unevenly. As shown in Figure 1, the horizontal axis is the uniform dimming level, and the vertical axis is the observer's visual brightness. The larger the dimming level, the greater the brightness of the lamp. Dark dimming refers to the process of adjusting the brightness of the lamp from a darker time to a certain brightness, and the dimming level corresponding to the dark dimming process is lower.

In order to solve the above-mentioned dimming jitter or dimming flicker problem, some existing dimming solutions skip the dimming process in the dark part and directly dim the light gradually from a brighter brightness. Accordingly, dimming starts directly from a higher dimming level and gradually increases the dimming level.

However, the human eye is more sensitive to sudden changes in brightness. For example, when you wake up in the middle of the night and turn on the light, you dare not open your eyes. Therefore, the existing technology skips the dimming process in the dark part and directly gradually brightens the brightness from a relatively bright state, which will cause the light of the lamp to suddenly become very bright when dimming begins, making it difficult for the human eye to adapt and affecting the experience.

Therefore, it is urgent to develop a dimming solution with smooth dark areas to meet user needs.

Summary of the invention

One advantage of the present application is that it provides a dimming lamp control method with smooth dark areas, wherein the dimming lamp control method with smooth dark areas can solve the problem of uneven dimming in dark areas, realize linear dimming in dark areas, avoid dimming jitter during dimming in dark areas, and ensure the comfort of human eyes during the dimming process.

Another advantage of the present application is that it provides a method for controlling a dimming lamp with smooth dark portions, wherein the method can adjust the current flowing through the dimmed light source in real time so that the current rising slope remains basically constant, thereby making the brightness of the light source transition smoothly and stably during the dark dimming process, so as to avoid dimming jitter during the dark dimming process.

Another advantage of the present application is that it provides a dimming lamp control method with smooth dark areas, wherein in the dimming lamp control method with smooth dark areas, the current flowing through the dimmed light source is sampled in real time, and an balancing device related to the hardware dimming system parameters is introduced to balance the voltage of the load unit of the constant current device load, so as to more accurately and dynamically compensate and adjust the nonlinear current, so that the current flowing through the dimmed light source changes linearly.

According to one aspect of the present application, a method for controlling a dimming lamp with smooth dimming is provided, which includes:

Preset system inherent dimming parameters;

Receive dimming parameter input data;

Outputting a PWM dimming signal based on the dimming parameter input data;

receiving a current acquisition signal, wherein the current acquisition signal represents a real-time output current of the constant current device; and

Controlling the resistance of the equalizing device based on the current acquisition signal to keep the load voltage of the constant current device unchanged, wherein the equalizing device is connected in series to the dimmed light source, the equalizing device and the dimmed light source together form a load unit, and the load unit is connected in series to the constant current device;

The preset system inherent dimming parameters include:

Measuring the real-time output current of the constant current device and the real-time voltage across the dimmed light source during the process in which the real-time output current of the constant current device rises from 0 to a peak value, and establishing and pre-storing a functional relationship between the real-time voltage across the dimmed light source and the real-time output current of the constant current device; and

measuring the load voltage of the constant current device when it is fully loaded;

Controlling the resistance of the equalizing device based on the current acquisition signal includes:

Determine the real-time resistance that the balancing device should achieve based on a functional relationship between the real-time voltage across the dimmed light source and the real-time output current of the constant current device, the load voltage of the constant current device when fully loaded, and the real-time output current of the constant current device represented by the current acquisition signal;

The real-time resistance that the equalizing device should reach is calculated by the following formula:

;

Wherein, R _t represents the real-time resistance that the balancing device should reach; V _LED is the load voltage of the constant current device; I _t represents the real-time output current of the constant current device; f(I _t ) represents the functional relationship between the real-time voltage across the dimmed light source and the real-time output current of the constant current device; wherein, in the process of controlling the resistance of the balancing device based on the current acquisition signal, the load voltage of the constant current device is maintained at the load voltage when the constant current device is fully loaded.

In one embodiment of the dimming lamp control method with smooth dimming in dark areas described in the present application, in the process of receiving dimming parameter input data, the dimming parameter input data is received by the control device, and in the process of outputting a PWM dimming signal based on the dimming parameter input data, the control device outputs a PWM dimming signal to the constant current device based on the dimming parameter input data, wherein the control device is connected to the constant current device, the constant current device is connected in series to the balancing device, and the balancing device is connected to the control device; in the process of receiving a current acquisition signal, the current acquisition signal from the current acquisition module is received by the control device, wherein the current acquisition module is connected in series to the constant current device and connected to the control device.

In one implementation of the dimming lamp control method with smooth dimming in the dark part according to the present application, the balancing device is a digital potentiometer, and the basic topology of the constant current device is a BUCK topology.

According to another aspect of the present application, another dimming lamp control method with smooth dimming is provided, which includes:

Preset system inherent dimming parameters;

Receive dimming parameter input data;

Outputting a PWM dimming signal based on the dimming parameter input data;

Receiving a current acquisition signal, wherein the current acquisition signal represents a real-time output current of the constant current device;

receiving a voltage acquisition signal, wherein the voltage acquisition signal represents a real-time voltage across the dimmed light source; and

Controlling the resistance of the equalizing device based on the current acquisition signal and the voltage acquisition signal to keep the load voltage of the constant current device unchanged, wherein the equalizing device is connected in series to the dimmed light source, the equalizing device and the dimmed light source together form a load unit, and the load unit is connected in series to the constant current device;

The preset system inherent dimming parameters include:

Measuring the load voltage of the constant current device when it is fully loaded by a voltage acquisition module;

Controlling the resistance of the equalizing device based on the current acquisition signal and the voltage acquisition signal includes:

Measuring the real-time voltage across the dimmed light source by means of the voltage acquisition module; and

Determine the real-time resistance that the balancing device should achieve based on the real-time voltage across the dimmed light source, the load voltage when the constant current device is fully loaded, and the real-time output current of the constant current device;

The real-time resistance that the equalizing device should reach is calculated by the following formula:

;

Wherein, R _t represents the real-time resistance that the balancing device should reach; V _LED is the load voltage of the constant current device; I _t represents the real-time output current of the constant current device; V _t represents the real-time voltage across the dimmed light source measured by the voltage acquisition module; wherein, in the process of controlling the resistance of the balancing device based on the current acquisition signal and the voltage acquisition signal, the load voltage of the constant current device is maintained at the load voltage when the constant current device is fully loaded.

In one implementation of the dimming lamp control method with smooth dimming described in the present application, the voltage acquisition module is connected in parallel to the light source to be dimmed.

In one embodiment of the dimming lamp control method with smooth dark areas described in the present application, in the process of receiving dimming parameter input data, the dimming parameter input data is received by the control device, and in the process of outputting a PWM dimming signal based on the dimming parameter input data, the control device outputs a PWM dimming signal to the constant current device based on the dimming parameter input data, wherein the control device is connected to the constant current device, the constant current device is connected in series to the balancing device, and the balancing device is connected to the control device; in the process of receiving a current acquisition signal, the current acquisition signal from the current acquisition module is received by the control device, wherein the current acquisition module is connected in series to the constant current device and connected to the control device; in the process of receiving a voltage acquisition signal, the voltage acquisition signal from the voltage acquisition module is received by the control device; the voltage acquisition module is connected to the control device, the balancing device is a digital potentiometer, and the basic topology of the constant current device is a BUCK topology.

Further objectives and advantages of the present application will be fully reflected through understanding of the following description and drawings.

These and other objects, features and advantages of the present application are fully reflected in the following detailed description, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

FIG. 1 is a schematic diagram showing how visual brightness changes with dimming levels during a conventional dimming process.

FIG. 2 is a schematic diagram showing a correspondence between a voltage waveform of a PWM dimming signal and a current waveform of a light source controlled by the PWM dimming signal in a conventional dimming process.

FIG. 3 illustrates a hardware dimming system in the prior art.

FIG. 4 is a schematic diagram showing the relationship between the current and voltage of a light source during a conventional dimming process.

FIG. 5 is a schematic diagram of a flow chart of an implementation of a method for controlling a dimming lamp with smooth dimming according to an embodiment of the present application.

FIG. 6 is a schematic diagram of a hardware dimming system in an implementation of a method for controlling a dimming lamp with smooth dimming in dark areas according to an embodiment of the present application, as shown in FIG. 5 .

FIG. 7 is a schematic flow chart of another implementation of a method for controlling a dimming lamp with smooth dimming according to an embodiment of the present application.

FIG. 8 illustrates a schematic diagram of a hardware dimming system in an implementation of a dimming lamp control method with smooth dimming in dark areas according to an embodiment of the present application as shown in FIG. 7 .

Detailed ways

Below, the exemplary embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the exemplary embodiments described here.

It is understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "one" cannot be understood as a limitation on the number. "Multiple" means greater than or equal to two.

Although ordinals such as "first," "second," and the like will be used to describe various components, those components are not limited herein. The term is used only to distinguish one component from another. For example, a first component may be referred to as a second component, and likewise, a second component may be referred to as a first component without departing from the teachings of the present application. The term "and/or" as used herein includes any and all combinations of one or more associated listed items.

The terms used herein are only used for the purpose of describing various embodiments and are not intended to be limiting. As used herein, singular forms are intended to include plural forms, unless the context clearly indicates an exception. In addition, it will be understood that the terms "including" and/or "having" when used in this specification specify the presence of the described features, numbers, steps, operations, components, elements, or combinations thereof, without excluding the presence or addition of one or more other features, numbers, steps, operations, components, elements, or groups thereof.

Application Overview: As mentioned above, in order to solve the above-mentioned dimming jitter or dimming flicker problems, some existing dimming solutions skip the dark dimming process and directly dim the light gradually from a brighter brightness. Accordingly, dimming starts directly from a higher dimming level and gradually increases the dimming level.

However, the human eye is more sensitive to sudden changes in brightness. For example, when you wake up in the middle of the night and turn on the light, you dare not open your eyes. Therefore, the existing technology skips the dimming process in the dark part and directly gradually brightens the brightness from a relatively bright state, which will cause the light of the lamp to suddenly become very bright when dimming begins, making it difficult for the human eye to adapt and affecting the experience.

Therefore, it is urgent to develop a dimming solution with smooth dark areas to meet user needs.

The inventor of the present application has found that in the prior art, one of the reasons for dimming jitter or dimming flicker is that the driving circuit of the lamp is nonlinear. Specifically, FIG. 2 illustrates a schematic diagram of the voltage waveform of a PWM (Pulse Width Modulation) dimming signal and a corresponding diagram of the current waveform of a light source controlled by the PWM dimming signal. FIG. 3 illustrates a hardware dimming system in the prior art. As shown in FIG. 2 and FIG. 3, the dimming system in the prior art includes a control device and a constant current device, wherein the control device sends a PWM dimming signal to the constant current device, and the constant current device drives the light source to work. In the process of controlling the light source by the PWM dimming signal, in each PWM cycle, the constant current device is turned on during the t _on time, and the constant current device is turned off during the t _off time; when the constant current device is turned on, the current rises from 0 to the rated current I; when the constant current device is turned off, the current drops from the rated current to 0. When darker dimming is required, that is, dimming in the dark part, t _on becomes narrower and falls at the current climbing position when the constant current device is turned on. When t _on is equal to t1 in the figure, the current waveform is a curve S1, so the dimming is nonlinear. In this way, when dimming in the dark part, the brightness of the light source changes nonlinearly, resulting in dimming jitter.

Based on the above findings, the inventors of the present application proposed that, during the dimming process, the current passing through the light source is allowed to rise linearly, as shown in the figure: the current passing through the light source is allowed to rise along the straight line OP.

Specifically, the rising slope of the current passing through the light source can be characterized by circuit parameters and calculated by the following formula:

(1);

Wherein, k is the rate of change of the current passing through the light source; Vin _is the input voltage of the constant current device, VLED is the load voltage of the constant current device; _and L is the inductance value of the inductor element when the constant current device is driven.

When working _, the input voltage of the constant current device remains unchanged and is _always Vin . When working, the inductance value of the inductor element remains unchanged when the constant current device is driven _and is always L. When working, VLED will change with the current. When a high-power light source is connected in series with multiple LED light sources, VLED changes more obviously with the current. As shown in Figure 4, when the LED forward current IF increases, its forward voltage VF value will also increase, that is _, VLED is increasing.

From the above, we can know that when the dimming level is increased at a uniform speed during the dimming process, the current flowing through the light source increases greatly, causing V _LED to increase. The rate of change of the current passing through the light source, that is, the slope k of the current passing through the light source, is increasing, so the current increment is an uneven nonlinear change. During the dimming process, the human eye has sharp vision, so the dimming jitter is seen (as shown in Figure 1). When the current climbs to the peak P, the current has a slight wave, called current ripple (as shown in Figure 2), which is generated by the working cycle of the constant current device. At this time, the bright dimming has been entered, and the human eye is dull at this time. The light received is still linearly changing and is not affected by the current ripple.

If the curve S0 is adjusted to a straight line S1, that is, if the current rises along a straight line, smooth dimming can be achieved throughout the process. If the load voltage V _LED of the constant current device is a constant value, the change rate k of the current passing through the adjusted light source can be controlled to be a constant value, and the current passing through the light source can rise along a straight line, thereby achieving smooth dimming throughout the process.

The present application samples the current flowing through the dimmed light source in real time, introduces an equalizing device related to the hardware dimming system parameters, equalizes the voltage of the load unit of the constant current device load, and dynamically compensates and adjusts the nonlinear current more accurately, so that the current flowing through the dimmed light source changes linearly, and the brightness of the light source transitions smoothly and stably during the dark dimming process, so as to avoid dimming jitter during the dark dimming process and ensure the comfort of the human eye during the dimming process.

Based on this, the present application proposes a dimming lamp control method with smooth dimming, which includes: receiving dimming parameter input data; outputting a PWM dimming signal based on the dimming parameter input data; receiving a current acquisition signal, the current acquisition signal representing the real-time output current of a constant current device; and controlling the resistance of an equalizing device based on the current acquisition signal to keep the load voltage of the constant current device unchanged, wherein the equalizing device is connected in series to the light source to be dimmed, the equalizing device and the light source to be dimmed together form a load unit, and the load unit is connected in series to the constant current device.

Schematic dimming lamp control method with smooth dark portion: as shown in Figures 5 to 8, a dimming lamp control method with smooth dark portion is described in accordance with an embodiment of the present application. Specifically, as shown in Figure 5, in one embodiment of the dimming lamp control method with smooth dark portion according to an embodiment of the present application, the dimming lamp control method with smooth dark portion includes: S110, receiving dimming parameter input data; S120, outputting a PWM dimming signal based on the dimming parameter input data; S130, receiving a current acquisition signal, the current acquisition signal characterizing the real-time output current of a constant current device; and, S140, controlling the resistance of an equalizing device based on the current acquisition signal to keep the load voltage of the constant current device unchanged, wherein the equalizing device is connected in series to the light source to be dimmed, the equalizing device and the light source to be dimmed together form a load unit, and the load unit is connected in series to the constant current device.

As mentioned above, the present application samples the current flowing through the dimmed light source in real time, introduces an equalizing device related to the hardware dimming system parameters, and equalizes the voltage of the load unit of the constant current device load. Accordingly, in the dimming light control method with smooth dark part, the hardware dimming system is adjusted. As shown in FIG6 , in one embodiment of the dimming light control method with smooth dark part, the hardware dimming system includes a control device, a constant current device, a current acquisition module and an equalizing device. The control device is connected to the constant current device; the current acquisition module is connected in series to the constant current device and connected to the control device; the equalizing device is connected to the control device, and the equalizing device is connected in series to the dimmed light source, and the equalizing device and the dimmed light source together form a load unit, and the load unit is connected in series to the constant current device. In this way, the constant current device is connected in series to the equalizing device. The basic topology of the constant current device is a BUCK topology. The current acquisition module is used to monitor the real-time current I _t output by the constant current device. The equalizing device can be a digital potentiometer (also known as a digitally controlled programmable resistor) with a resistance of R. The light source to be dimmed may be an LED light source, and each light source may be one or more LEDs connected in series, in parallel, or in mixed connection.

In step S110, dimming parameter input data is received. Specifically, the dimming parameter input data input by the user is received by the control device.

In step S120, a PWM dimming signal is output based on the dimming parameter input data. Specifically, the control device outputs a PWM dimming signal to the constant current device based on the dimming parameter input data.

In step S130, a current acquisition signal is received. Specifically, the current acquisition signal from the current acquisition module is received by the control device.

In step S140, the resistance of the equalizing device is controlled based on the current acquisition signal. Specifically, the control device controls the resistance of the equalizing device based on the current acquisition signal, and the load unit of the constant current device load is equalized, so that the load voltage of the constant current device remains unchanged, thereby making the brightness of the light source smoothly and stably transition during the dark dimming process, so as to avoid dimming jitter during the dark dimming process and ensure the comfort of human eyes during the dimming process.

Prior to this, that is, before step S110 to step S140, the dimming lamp control method with smooth dimming in dark areas further includes step S150, presetting the inherent dimming parameters of the system.

In the process of presetting the inherent dimming parameters of the system, first, it is necessary to measure the relationship data table between the real-time current I _t and the real-time voltage V _t at both ends of the light source during the process of the original constant current device current rising from 0 to the peak point P, and preset it in the control device for query, recorded as:

(2);

Then, the load voltage and f(I _t ) of the original constant current device when fully loaded are measured as the inherent dimming parameters of the system.

Accordingly, in this embodiment, step S150 includes: S151, measuring the real-time output current of the constant current device and the real-time voltage across the dimmed light source during the process of the real-time output current of the constant current device rising from 0 to the peak value, and establishing and pre-storing a functional relationship between the real-time voltage across the dimmed light source and the real-time output current of the constant current device; and, S152, measuring the load voltage of the constant current device when it is fully loaded.

In the process of controlling the resistance of the equalizing device based on the current acquisition signal to keep the load voltage of the constant current device unchanged, assuming that the current of the constant current device rises from 0 to the peak point P, the voltage across the equalizing device implemented as a digital potentiometer is recorded _{as VR} , which is calculated by the following formula:

(3);

According to Ohm's law R=U/I, the real-time _resistance Rt of the digital potentiometer can be further obtained as:

(4);

Combining equations (2), (3), and (4), we can obtain:

(5);

The current acquisition module monitors the real-time current I _t output by the constant current device, and uses the corresponding rule f(I _t ) to look up the table in the control device to obtain the corresponding voltage V _t . The difference obtained by subtracting V _t from the load voltage of the constant current device is divided by the real-time current I _t to calculate the undetermined real-time resistance R _t of the digital potentiometer. At this time, the control device outputs the required signal to the digital potentiometer to meet the adjustment to the required resistance value. In the process of controlling the resistance of the equalizing device based on the current acquisition signal, the load voltage of the constant current device is kept constant, and the load voltage of the constant current device when it is fully loaded can be used as the constant value.

From the perspective of full-range regulation, the digital potentiometer dynamically compensates _{the voltage VR} , making _{the load voltage VLED} of the constant current device a constant value. According to formula (1), the current will climb along the straight line OP. The expected purpose is achieved.

Correspondingly, step S140 includes: determining the real-time resistance that the balancing device should reach based on the functional relationship between the real-time voltage across the dimmed light source and the real-time output current of the constant current device, the load voltage of the constant current device when fully loaded, and the real-time output current of the constant current device represented by the current acquisition signal.

The real-time resistance that the equalizing device should reach is calculated by the following formula:

;

Wherein, R _t represents the real-time resistance that the balancing device should reach; V _LED is the load voltage of the constant current device; I _t represents the real-time output current of the constant current device; f(I _t ) represents the functional relationship between the real-time voltage across the dimmed light source and the real-time output current of the constant current device; wherein, in the process of controlling the resistance of the balancing device based on the current acquisition signal, the load voltage of the constant current device is maintained at the load voltage when the constant current device is fully loaded.

As shown in Figure 7, in another implementation of the dimming lamp control method with smooth dark areas according to the embodiment of the present application, the dimming lamp control method with smooth dark areas includes: S210, receiving dimming parameter input data; S220, outputting a PWM dimming signal based on the dimming parameter input data; S230, receiving a current acquisition signal, wherein the current acquisition signal represents the real-time output current of the constant current device; S240, receiving a voltage acquisition signal, wherein the voltage acquisition signal represents the real-time voltage across the dimmed light source; and, S250, controlling the resistance of the balancing device based on the current acquisition signal and the voltage acquisition signal to keep the load voltage of the constant current device unchanged, wherein the balancing device is connected in series to the dimmed light source, and the balancing device and the dimmed light source together form a load unit, and the load unit is connected in series to the constant current device.

As shown in FIG8 , in one embodiment of the dimming lamp control method with smooth dimming shown in FIG7 , the hardware dimming system includes a control device, a constant current device, a current acquisition module, a voltage acquisition module and an equalizing device. The control device is connected to the constant current device; the current acquisition module is connected in series to the constant current device and connected to the control device; the equalizing device is connected to the control device, and the equalizing device is connected in series to the light source to be dimmed, and the equalizing device and the light source to be dimmed together form a load unit, and the load unit is connected in series to the constant current device. In this way, the constant current device is connected in series to the equalizing device. The basic topology of the constant current device is a BUCK topology. The current acquisition module is used to monitor the real-time current I _t output by the constant current device. The voltage acquisition module is used to monitor the real-time voltage V _t at both ends of the light source to be dimmed. The equalizing device can be a digital potentiometer (also known as a digitally controlled programmable resistor), and its resistance value is R. The light source to be dimmed can be an LED light source, and each light source can be one or more LEDs connected in series, in parallel, or in mixed series. The voltage collection module is connected in parallel to the light source to be dimmed, and is also connected to the control device.

In step S210, dimming parameter input data is received. Specifically, the dimming parameter input data input by the user is received by the control device.

In step S220, a PWM dimming signal is output based on the dimming parameter input data. Specifically, the control device outputs a PWM dimming signal to the constant current device based on the dimming parameter input data.

In step S230, a current acquisition signal is received. Specifically, the current acquisition signal from the current acquisition module is received by the control device.

In step S240, a voltage acquisition signal is received. Specifically, the voltage acquisition signal from the voltage acquisition module is received by the control device.

In step S250, the resistance of the equalizing device is controlled based on the current acquisition signal and the voltage acquisition signal. Specifically, the control device controls the resistance of the equalizing device based on the current acquisition signal and the voltage acquisition signal, and the load unit of the constant current device load is equalized, so that the load voltage of the constant current device remains unchanged, thereby making the brightness of the light source smoothly and stably transition during the dark dimming process, so as to avoid dimming jitter during the dark dimming process and ensure the comfort of human eyes during the dimming process.

Prior to this, that is, before step S210 to step S250, the dimming lamp control method with smooth dimming in dark areas further includes step S260, presetting the inherent dimming parameters of the system.

In the process of presetting the inherent dimming parameters of the system, it is necessary to measure the load voltage of the original constant current device when it is fully loaded. The load voltage of the constant current device when it is fully loaded is the inherent dimming parameter of the system.

Accordingly, in this embodiment, step S260 includes: measuring the load voltage of the constant current device when it is fully loaded by a voltage acquisition module.

In the process of controlling the resistance of the equalizing device based on the current acquisition signal and the voltage acquisition signal, assuming that the current of the constant current device rises from 0 to the peak point P, the _{voltage across the digital potentiometer is recorded as VR} , which is calculated by the following formula:

(6);

According to Ohm's law R=U/I, the real-time _resistance Rt of the digital potentiometer can be further obtained as:

(7);

Combining equations (6) and (7), we can obtain:

(8);

The current acquisition module monitors the real-time current I _t output by the constant current device, and the voltage acquisition module monitors the real-time voltage V _t across the light source. The difference obtained by subtracting V _t from the load voltage of the constant current device when fully loaded is divided by the real-time current I _t to calculate the real-time resistance R _t of the digital potentiometer to be determined. At this time, the control device outputs the required signal to the digital potentiometer to meet the adjustment to the required resistance value.

From the perspective of full-range regulation, the digital potentiometer dynamically compensates the voltage V _LED , making the load voltage V _LED of the constant current device a constant value. According to formula (1), the current will climb along the straight line OP. The expected purpose is achieved.

Accordingly, controlling the resistance of the equalizing device based on the current acquisition signal and the voltage acquisition signal includes: measuring the real-time voltage across the dimmed light source through the voltage acquisition module; and determining the real-time resistance that the equalizing device should reach based on the real-time voltage across the dimmed light source, the load voltage when the constant current device is fully loaded, and the real-time output current of the constant current device. The real-time resistance that the equalizing device should reach is calculated by the following formula:

;

Wherein, R _t represents the real-time resistance that the balancing device should reach; V _LED is the load voltage of the constant current device; I _t represents the real-time output current of the constant current device; V _t represents the real-time voltage across the dimmed light source measured by the voltage acquisition module; wherein, in the process of controlling the resistance of the balancing device based on the current acquisition signal and the voltage acquisition signal, the load voltage of the constant current device is maintained at the load voltage when the constant current device is fully loaded.

In summary, a dimming lamp control method with smooth dark areas based on the embodiment of the present application is explained. The dimming lamp control method with smooth dark areas balances the voltage of the load unit of the constant current device load, and more accurately and dynamically compensates and adjusts the nonlinear current, so that the current flowing through the dimmed light source changes linearly, so that the brightness of the light source transitions smoothly and stably during the dimming process, so as to avoid dimming jitter during the dimming process and ensure the comfort of the human eye during the dimming process.

The present application and its implementation methods are described above, and such description is not restrictive. The drawings show only one implementation method of the present application, and the actual structure is not limited thereto. In short, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creative design without departing from the inventive purpose of the present application, they should all fall within the protection scope of the present application.

Claims (6)

1. A dimming lamp control method with smooth dimming, comprising: Preset system inherent dimming parameters; Receive dimming parameter input data; Outputting a PWM dimming signal based on the dimming parameter input data; receiving a current acquisition signal, wherein the current acquisition signal represents a real-time output current of the constant current device; and Controlling the resistance of the equalizing device based on the current acquisition signal to keep the load voltage of the constant current device unchanged, wherein the equalizing device is connected in series to the dimmed light source, the equalizing device and the dimmed light source together form a load unit, and the load unit is connected in series to the constant current device; The preset system inherent dimming parameters include: Measuring the real-time output current of the constant current device and the real-time voltage across the dimmed light source during the process in which the real-time output current of the constant current device rises from 0 to a peak value, and establishing and pre-storing a functional relationship between the real-time voltage across the dimmed light source and the real-time output current of the constant current device; and measuring the load voltage of the constant current device when it is fully loaded; Controlling the resistance of the equalizing device based on the current acquisition signal includes: Determine the real-time resistance that the balancing device should achieve based on a functional relationship between the real-time voltage across the dimmed light source and the real-time output current of the constant current device, the load voltage of the constant current device when fully loaded, and the real-time output current of the constant current device represented by the current acquisition signal; The real-time resistance that the equalizing device should reach is calculated by the following formula: ; in, Indicates the real-time resistance that the equalizing device should achieve; /> is the load voltage of the constant current device; Indicates the real-time output current of the constant current device; /> A functional formula representing the real-time voltage across the dimmed light source relative to the real-time output current of the constant current device; wherein, in the process of controlling the resistance of the equalizing device based on the current acquisition signal, the load voltage of the constant current device is maintained at the load voltage when the constant current device is fully loaded. 2. The dimming lamp control method with smooth dimming in dark areas according to claim 1 is characterized in that, in the process of receiving dimming parameter input data, the dimming parameter input data is received by the control device, and in the process of outputting a PWM dimming signal based on the dimming parameter input data, the control device outputs a PWM dimming signal to the constant current device based on the dimming parameter input data, wherein the control device is connected to the constant current device, the constant current device is connected in series to the balancing device, and the balancing device is connected to the control device; in the process of receiving a current acquisition signal, the current acquisition signal from the current acquisition module is received by the control device, wherein the current acquisition module is connected in series to the constant current device and connected to the control device. 3. The dimming lamp control method with smooth dimming in dark areas according to claim 1, characterized in that the balancing device is a digital potentiometer, and the basic topology of the constant current device is a BUCK topology. 4. A dimming lamp control method with smooth dimming, characterized by comprising: Preset system inherent dimming parameters; Receive dimming parameter input data; Outputting a PWM dimming signal based on the dimming parameter input data; Receiving a current acquisition signal, wherein the current acquisition signal represents a real-time output current of the constant current device; receiving a voltage acquisition signal, wherein the voltage acquisition signal represents a real-time voltage across the dimmed light source; and Controlling the resistance of the equalizing device based on the current acquisition signal and the voltage acquisition signal to keep the load voltage of the constant current device unchanged, wherein the equalizing device is connected in series to the dimmed light source, the equalizing device and the dimmed light source together form a load unit, and the load unit is connected in series to the constant current device; Presetting the inherent dimming parameters of the system includes: measuring the load voltage of the constant current device when it is fully loaded through a voltage acquisition module; Controlling the resistance of the equalizing device based on the current acquisition signal and the voltage acquisition signal includes: Measuring the real-time voltage across the dimmed light source by means of the voltage acquisition module; and Determine the real-time resistance that the balancing device should achieve based on the real-time voltage across the dimmed light source, the load voltage when the constant current device is fully loaded, and the real-time output current of the constant current device; The real-time resistance that the equalizing device should reach is calculated by the following formula: ; in, Indicates the real-time resistance that the equalizing device should achieve; /> is the load voltage of the constant current device; Indicates the real-time output current of the constant current device; /> Represents the real-time voltage across the dimmed light source measured by the voltage acquisition module; wherein, in the process of controlling the resistance of the equalizing device based on the current acquisition signal and the voltage acquisition signal, the load voltage of the constant current device is maintained at the load voltage when the constant current device is fully loaded. 5. The method for controlling a dimming lamp with smooth dimming according to claim 4, wherein the voltage acquisition module is connected in parallel to the light source to be dimmed. 6. The dimming lamp control method with smooth dimming in dark areas according to claim 5 is characterized in that, in the process of receiving dimming parameter input data, the dimming parameter input data is received by the control device, and in the process of outputting a PWM dimming signal based on the dimming parameter input data, the PWM dimming signal is output to the constant current device based on the dimming parameter input data by the control device, wherein the control device is connected to the constant current device, the constant current device is connected in series to the equalizing device, and the equalizing device is connected to the control device; in the process of receiving a current acquisition signal, the current acquisition signal from the current acquisition module is received by the control device, wherein the current acquisition module is connected in series to the constant current device and connected to the control device; in the process of receiving a voltage acquisition signal, the voltage acquisition signal from the voltage acquisition module is received by the control device; the voltage acquisition module is connected to the control device, the equalizing device is a digital potentiometer, and the basic topology of the constant current device is a BUCK topology.