Gradient lighting switch control circuit and lighting lamp

Abstract

The utility model provides a gradual change type lighting switch control circuit. The gradual change type lighting switch control circuit comprises an input preprocessing module, a boost conversion module, a flyback conversion module, a step-down constant current module, a voltage detection output module and a single-chip microcomputer control module. The boost conversion module can quickly adjust the harmonic content of the current, keep synchronization with the waveform of the input current, and meet the requirement for the harmonic current. The single-chip microcomputer control module accurately controls the current of the lighting load by outputting a gradually-changed PWM duty ratio signal to the step-down constant-current module, so that the effects of slowly lighting on the lamp and slowly extinguishing off the lamp are achieved. Besides, the circuit is also provided with a first dial switch and a second dial switch, so that the slow lighting time of the lighting load in the light turning-on process can be adjusted, and the flexibility of the gradual change type lighting switch control circuit is improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of lighting drive control, and particularly relates to a gradual lighting switch control circuit and a lighting lamp. BACKGROUND

[0002] In the field of LED lighting, it is important to improve user experience to realize the function of slow lighting of LED lamp when switch is turned on and gradual extinguishing after power-off. Specifically, in the process of extinguishing of LED lamp, the energy of LED lamp mainly depends on the discharge of electrolytic capacitor at the input end to maintain, so that the electrolytic capacitor must have sufficient capacity.

[0003] However, in order to meet the capacity requirement of electrolytic capacitor, the traditional low power factor LED drive circuit is prone to increase harmonic current after increasing the capacity of input electrolytic capacitor, so that the low power factor LED drive circuit is difficult to meet the harmonic requirement in the existing standard document, thereby increasing the difficulty of product design and production.

[0004] On the other hand, the existing LED lighting lamp with brightness gradient is often difficult to adjust the brightness and the time of gradient work at the same time, thereby making the LED lighting lamp function single and not conducive to the application of the lamp in diversified scenes. CONTENT OF THE INVENTION

[0005] The purpose of the present disclosure is to overcome the deficiencies in the prior art, and to provide a gradual lighting switch control circuit and a lighting lamp capable of adjusting brightness and slow lighting time.

[0006] The purpose of the present disclosure is achieved by the following technical solutions:

[0007] A gradual lighting switch control circuit, comprising an input preprocessing module, a flyback conversion module, a step-down constant current module, a step-up conversion module, a voltage detection output module and a single-chip microcomputer control module,

[0008] The input end of the input preprocessing module is used to be connected with an external power supply end, the output end of the input preprocessing module is connected with the input end of the step-up conversion module, the output end of the step-up conversion module is connected with the input end of the flyback conversion module, the output end of the flyback conversion module is respectively connected with the input end of the step-down constant current module and the voltage stabilization input end of the voltage detection output module, and the output end of the step-down constant current module is used to provide electric energy for a lighting load.

[0009] The boost conversion module includes a boost controller, an energy storage boost inductor, a freewheeling diode and an electrolytic capacitor, the first end of the energy storage boost inductor is connected with the output end of the input preprocessing module, the second end of the energy storage boost inductor is connected with the positive electrode of the freewheeling diode and the switch control end of the boost controller respectively, the negative electrode of the freewheeling diode is connected with the positive electrode of the electrolytic capacitor, the positive electrode of the electrolytic capacitor is connected with the input end of the flyback conversion module, and the negative electrode of the electrolytic capacitor is grounded.

[0010] The single-chip microcomputer control module includes a first microcontroller, a first voltage dividing resistor, a second voltage dividing resistor, a first DIP switch and a second DIP switch, the power supply end of the first microcontroller is connected with the voltage stabilization output end of the voltage detection output module, one end of the first DIP switch is connected with the first switch signal end of the first microcontroller through the first voltage dividing resistor, one end of the second DIP switch is connected with the second switch signal end of the first microcontroller through the second voltage dividing resistor, the other end of the first DIP switch and the other end of the second DIP switch are connected with the power supply end of the first microcontroller respectively, the voltage signal detection end of the first microcontroller is connected with the voltage signal output end of the voltage detection output module, the PWM signal output end of the first microcontroller is connected with the PWM signal receiving end of the step-down constant current module, and the voltage signal input end of the voltage detection output module is connected with the external power supply end.

[0011] In one of the embodiments, the step-down constant current module includes a second microcontroller, a third voltage dividing resistor, a fourth voltage dividing resistor, a third DIP switch and a fourth DIP switch, the first end of the third DIP switch is connected with the first end of the fourth DIP switch, the second end of the third DIP switch is connected with the digital input end of the second microcontroller through the third voltage dividing resistor, the second end of the fourth DIP switch is connected with the digital input end of the second microcontroller through the fourth voltage dividing resistor, the first end of the third DIP switch is connected with the power supply end of the second microcontroller, the power supply end of the second microcontroller is connected with the output end of the flyback conversion module, the output end of the second microcontroller is used for being connected with a load module, and the PWM signal receiving end of the second microcontroller is connected with the PWM signal output end of the first microcontroller.

[0012] In one of the embodiments, the step-down constant current module further includes a first current limiting resistor, the first end of the first current limiting resistor is connected with the PWM signal output end of the first microcontroller, and the second end of the first current limiting resistor is connected with the PWM signal receiving end of the second microcontroller.

[0013] In one of the embodiments, the voltage reduction constant current module further comprises a first filter capacitor, a first end of the first filter capacitor is connected with the PWM signal receiving end of the second microcontroller, and a second end of the first filter capacitor is grounded.

[0014] In one of the embodiments, the input pretreatment module comprises an interference suppression circuit and a first rectifier bridge circuit, an input end of the interference suppression circuit is connected with an external power supply end, an output end of the interference suppression circuit is connected with an input end of the first rectifier bridge circuit, and an output end of the first rectifier bridge circuit is connected with a first end of the energy storage voltage boosting inductor.

[0015] In one of the embodiments, the voltage detection output module comprises an alternating current input voltage detection circuit and a linear voltage stabilizing circuit, the alternating current input voltage detection circuit comprises a second rectifier bridge circuit, a second current limiting resistor and a photoelectric coupler, an input end of the second rectifier bridge circuit is connected with an output end of the interference suppression circuit, an output end of the second rectifier bridge circuit is connected with a first end of the second current limiting resistor, a second end of the second current limiting resistor is connected with an input end of the photoelectric coupler, an input end of the linear voltage stabilizing circuit is connected with an output end of the flyback conversion module, a first end of a photoelectric coupler phototriode and a power supply input end of the first microcontroller are respectively connected with an output end of the linear voltage stabilizing circuit, and a second end of the photoelectric coupler phototriode is connected with a voltage signal detection end of the first microcontroller.

[0016] In one of the embodiments, the linear voltage stabilizing circuit comprises a first electronic switch tube, a voltage stabilizing diode and a first bias resistor, a first end of the first electronic switch tube is connected with an output end of the flyback conversion module, a first end of the first bias resistor is connected with the first end of the first electronic switch tube, a second end of the first bias resistor is connected with a control end of the first electronic switch tube, a negative electrode of the voltage stabilizing diode is connected with the control end of the first electronic switch tube, a positive electrode of the voltage stabilizing diode is grounded, and a second end of the first electronic switch tube is connected with a first end of the photoelectric coupler phototriode.

[0017] In one of the embodiments, the flyback conversion module comprises a transformer and a secondary side rectification diode, an input end of the transformer is connected with a positive electrode of the electrolytic capacitor, an output end of the transformer is connected with a positive electrode of the secondary side rectification diode, and a negative electrode of the secondary side rectification diode is connected with an input end of the voltage reduction constant current module.

[0018] In one of the embodiments, the single-chip microcomputer control module further comprises a second filter capacitor, a first end of the second filter capacitor is connected with a power supply end of the first microcontroller, and a second end of the second filter capacitor is grounded.

[0019] This application also provides a lighting fixture, including the gradient lighting switch control circuit described in any embodiment.

[0020] Compared with the prior art, this disclosure has at least the following advantages:

[0021] 1. The above-mentioned gradual lighting switch control circuit, due to the use of a boost converter module, can quickly adjust the harmonic content of the current when the input current changes due to the electrolytic capacitor, so as to keep it synchronized with the input current waveform. This allows the harmonic current to actively follow the input current waveform for correction, and even if the electrolytic capacitor capacity is increased, it can still meet the requirements for harmonic current in the existing standard documents.

[0022] 2. On the other hand, the first microcontroller outputs a gradually changing PWM duty cycle signal to the step-down constant current module, thereby precisely controlling the current output by the step-down constant current module to the lighting load, thus achieving the effect of the lighting load turning on slowly and turning off slowly.

[0023] 3. In addition, the lighting load's slow-on time during the lighting process can be adjusted by the first and second DIP switches, thereby improving the flexibility of the gradual lighting switch control circuit. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A circuit diagram of a gradient lighting switch control circuit according to one embodiment;

[0026] Figure 2 for Figure 1 The diagram shows a partial circuit of the input preprocessing module.

[0027] Figure 3 for Figure 1 The diagram shows a partial circuit of the boost converter module.

[0028] Figure 4 for Figure 1 The diagram shows a partial circuit of the flyback converter module.

[0029] Figure 5 for Figure 1 The diagram shows a partial circuit of the step-down constant current module.

[0030] Figure 6 forFigure 1 partial circuit diagram of the gradient lighting switch control circuit;

[0031] Figure 7 For Figure 1 partial circuit diagram of the single-chip microcomputer control module. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the accompanying drawings. The preferred embodiments of the present disclosure are shown in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thorough and comprehensive.

[0033] It should be noted that when an element is referred to as being "fixed" to another element, it can be directly on the other element or there can be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there can be an intervening element. The terms "vertical", "horizontal", "left", "right", and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in the description of the disclosure herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0035] In order to better understand the technical solutions and beneficial effects of the present disclosure, the present disclosure will be further described in detail below in combination with specific embodiments:

[0036] As Figures 1 to 7 The gradient lighting switch control circuit 10 of an embodiment of the present disclosure includes an input preprocessing module 100, a boost conversion module 200, a flyback conversion module 300, a step-down constant current module 400, a voltage detection output module 500, and a single-chip microcomputer control module 600.

[0037] The input end of the input preprocessing module 100 is used to be connected with an external power supply end. The output end of the input preprocessing module 100 is connected with the input end of the boost conversion module 200. The output end of the boost conversion module 200 is connected with the input end of the flyback conversion module 300. The output end of the flyback conversion module 300 is respectively connected with the input end of the step-down constant current module 400 and the voltage stabilization input end of the voltage detection output module 500. The output end of the step-down constant current module 400 is used to provide power for a lighting load.

[0038] The boost conversion module 200 comprises a boost controller U1, an energy storage boost inductor L2, a freewheeling diode D2 and an electrolytic capacitor CE1. The first end of the energy storage boost inductor L2 is connected to the output end of the input preprocessing module 100. The second end of the energy storage boost inductor L2 is connected to the anode of the freewheeling diode D2 and the switch control end of the boost controller U1, respectively. The cathode of the freewheeling diode D2 is connected to the anode of the electrolytic capacitor CE1. The anode of the electrolytic capacitor CE1 is connected to the input end of the flyback conversion module 300. The cathode of the electrolytic capacitor CE1 is grounded.

[0039] The single-chip microcomputer control module 600 comprises a first microcontroller U5, a first voltage dividing resistor R27, a second voltage dividing resistor R26, a first DIP switch SW3 and a second DIP switch SW4. The power supply end VDD of the first microcontroller U5 is connected to the voltage stabilization output end of the voltage detection output module 500. One end of the first DIP switch SW3 is connected to the first switch signal end Switch3 of the first microcontroller U5 through the first voltage dividing resistor R27. One end of the second DIP switch SW4 is connected to the second switch signal end Switch4 of the first microcontroller U5 through the second voltage dividing resistor R26. The other end of the first DIP switch SW3 and the other end of the second DIP switch SW4 are connected to the power supply end VDD of the first microcontroller U5, respectively. The voltage signal detection end I / O1 of the first microcontroller U5 is connected to the voltage signal output end of the voltage detection output module 500. The PWM signal output end of the first microcontroller U5 is connected to the PWM signal receiving end of the step-down constant current module 400. The voltage signal input end of the voltage detection output module 500 is connected to the external power supply end.

[0040] In the embodiment, the input pre-processing module 100 includes anti-interference filter, surge protection and rectifier circuit. When the switch is closed, the external power supply outputs current, which is first processed by the input pre-processing module 100 to remove electromagnetic interference or surge current, and then transmitted to the rectifier circuit in the input pre-processing module 100, which converts alternating current into direct current. Further, the rectified and filtered direct current is transmitted to the energy storage boost inductor L2 of the boost conversion module 200. At this time, the current passes through the energy storage boost inductor L2, and then the current is conducted to the boost controller U1, which controls the charging and discharging time of the electrolytic capacitor CE1 by setting the conduction duty cycle of the switching device in the boost controller U1. The electrolytic capacitor CE1 acts as an energy storage element and provides a stable DC power supply for the flyback converter. Then, the flyback converter module further adjusts the voltage and transmits the electrical energy to the step-down constant current module 400. Since the PWM signal output end of the first microcontroller U5 of the single-chip microcomputer control module 600 is connected to the PWM signal receiving end of the step-down constant current module 400, the output current of the step-down constant current module 400 is controlled by the PWM signal output by the first microcontroller U5, so that the load module obtains a gradually changing output current, and the lighting load is in a slow brightening state during the light-on process.

[0041] Specifically, when the main switch in the circuit is closed, the lighting load enters the slow brightening process, and the voltage detection output module 500 detects that the external power supply is in a normal power supply state, and at the same time, the voltage detection output module 500 transmits the voltage signal to the first microcontroller U5 of the single-chip microcomputer control module 600 through the internal photoelectric coupler U3. At this time, the first microcontroller U5 outputs a gradually increasing PWM duty cycle signal to the PWM signal receiving end of the step-down constant current module 400 according to the detected voltage signal, so that the current output by the step-down constant current module 400 to the load gradually increases from small to large, and the lighting load realizes the slow brightening process during the light-on process. The slow brightening time of the lighting load during the light-on process can be adjusted by the first dial switch SW3 and the second dial switch SW4. For example, in one setting mode of the first microcontroller U5, the first dial switch SW3 is closed, which can increase the slow brightening time, i.e., the time from the lighting load being turned off to being fully turned on will be extended; and the second dial switch SW4 is closed, which can further increase the slow brightening time, and the second dial switch SW4 and the first dial switch SW3 are closed at the same time, which can achieve the cumulative effect of increasing the slow brightening time. Conversely, when the first dial switch SW3 is opened, the slow brightening time can be reduced, i.e., the time from the lighting load being turned off to being fully turned on will be shortened compared to when the first dial switch SW3 is closed; similarly, when the second dial switch SW4 is opened, the slow brightening time can be further shortened.

[0042] Further, in another setting mode of the first microcontroller U5, when the first dial switch SW3 is closed, the time from the lighting load being off to being fully on can be reduced; and when the second dial switch SW4 is closed, the time of the dimming process can be further reduced; on the contrary, when the first dial switch SW3 is open, the time of the dimming process can be increased, i.e. the time from the lighting load being off to being fully on will be prolonged compared to when the first dial switch SW3 is closed; similarly, when the second dial switch SW4 is open, the time of the dimming process can be further increased. Thus, the user can set the dimming time of the lighting load according to his own needs, thereby improving the flexibility of the gradual lighting switch control circuit 10.

[0043] Further, when the main switch in the circuit is open, the lighting load enters the dimming process, and the input preprocessing module 100 and the boost converter module 200 are in a stopped working state. At this time, the electrolytic capacitor CEl starts to discharge, and since the capacity of the electrolytic capacitor CEl is large enough, it can continue to provide voltage for the flyback converter for a period of time, so that the flyback converter can still work for a period of time, and thus the step-down constant current module 400 can still output current to the load. At the same time, since the voltage detection output module 500 detects that the input preprocessing module 100 does not output a voltage signal, and the voltage signal detection end I / O1 of the first microcontroller U5 is connected with the voltage signal output end of the voltage detection output module 500, the voltage signal detection end I / O1 of the first microcontroller U5 loses the voltage signal, thereby driving the PWM signal output end of the first microcontroller U5 to output a gradually decreasing PWM duty cycle signal to the PWM signal receiving end of the step-down constant current module 400, and thus controlling the current output by the step-down constant current module 400 to the load to gradually decrease, so as to achieve the effect of gradually decreasing the brightness of the lighting load.

[0044] The gradual lighting switch control circuit 10 described above, since the boost converter module 200 is adopted, when the input current changes due to the change of the electrolytic capacitor CEl, the boost converter module 200 can quickly adjust the harmonic content of the current to keep synchronization with the input current waveform, so that the harmonic current actively follows the input current waveform for correction, and thus even if the capacity of the electrolytic capacitor CEl increases, the requirements for the harmonic current in the existing standard documents can still be met. On the other hand, by outputting the gradual PWM duty cycle signal by the first microcontroller U5 to the step-down constant current module 400, the current output by the step-down constant current module 400 to the lighting load can be accurately controlled, thereby achieving the effects of slow lighting when the lighting load is turned on and slow dimming when the lighting load is turned off. In addition, the first dial switch SW3 and the second dial switch SW4 can be used to adjust the slow lighting time of the lighting load when it is turned on, thereby improving the flexibility of the gradual lighting switch control circuit 10.

[0045] As Figure 1 and Figure 5As shown, in one embodiment, the buck constant current module 400 includes a second microcontroller U4, a third voltage dividing resistor R23, a fourth voltage dividing resistor R22, a third DIP switch SW1 and a fourth DIP switch SW2. The first end of the third DIP switch SW1 is connected to the first end of the fourth DIP switch SW2. The second end of the third DIP switch SW1 is connected to the digital input end of the second microcontroller U4 through the third voltage dividing resistor R23. The second end of the fourth DIP switch SW2 is connected to the digital input end of the second microcontroller U4 through the fourth voltage dividing resistor R22. The first end of the third DIP switch SW1 is connected to the power supply end of the second microcontroller U4. The power supply end of the second microcontroller U4 is connected to the output end of the flyback conversion module 300. The output end of the second microcontroller U4 is used to be connected to the load module. The PWM signal receiving end of the second microcontroller U4 is connected to the PWM signal output end of the first microcontroller U5. In this embodiment, the buck constant current module 400 receives the PWM signal output by the PWM signal output end of the first microcontroller U5 through the PWM signal receiving end of the second microcontroller U4, so that the buck constant current module 400 can adjust the power output to the lighting load according to the PWM signal output by the first microcontroller U5, thereby finely controlling the load current and accurately adjusting the brightness change of the lighting load. In addition, by adjusting the on-off state of the third DIP switch SW1 and the fourth DIP switch SW2, the maximum output current of the power supply can be adjusted, thereby controlling the brightness of the lighting load. Specifically, when the third DIP switch SW1 is closed, the maximum output current of the power supply is set to a certain value, for example, 350mA, so that the maximum brightness of the lighting load is limited by this current value. When the fourth DIP switch SW2 is closed, the maximum output current of the power supply will be further increased, for example, to 400mA, and the maximum output current of the power supply is determined by the larger value set in the two, that is, when the third DIP switch SW1 and the fourth DIP switch SW2 are both in the closed state, the larger value in the two will be used as the maximum output current set by the power supply.

[0046] As Figure 1 and Figure 5As shown in the figure, in one of the embodiments, the buck constant current module 400 further comprises a first current-limiting resistor R18, a first end of the first current-limiting resistor R18 is connected with the PWM signal output end of the first microcontroller U5, and a second end of the first current-limiting resistor R18 is connected with the PWM signal receiving end of the second microcontroller U4. In this embodiment, the main role of the first current-limiting resistor R18 is to limit the current and stably transmit the PWM signal output from the first microcontroller U5. When the first microcontroller U5 outputs a gradually changing PWM signal to control the brightness gradual change of the lighting load according to the feedback signal of the voltage detection output module 500, at this time, the PWM signal may generate current fluctuation or excessive transient current due to line impedance, electromagnetic interference or mismatch between modules. The first current-limiting resistor R18 can effectively limit the size of the transient current, thereby protecting the second microcontroller U4 of the buck constant current module 400 from being damaged or appearing abnormal state due to excessive current impact.

[0047] As shown in the figure, Figure 1 and Figure 5 As shown in the figure, in one of the embodiments, the buck constant current module 400 further comprises a first current-limiting resistor R18, a first end of the first current-limiting resistor R18 is connected with the PWM signal output end of the first microcontroller U5, and a second end of the first current-limiting resistor R18 is connected with the PWM signal receiving end of the second microcontroller U4. In this embodiment, the main role of the first current-limiting resistor R18 is to limit the current and stably transmit the PWM signal output from the first microcontroller U5. When the first microcontroller U5 outputs a gradually changing PWM signal to control the brightness gradual change of the lighting load according to the feedback signal of the voltage detection output module 500, at this time, the PWM signal may generate current fluctuation or excessive transient current due to line impedance, electromagnetic interference or mismatch between modules. The first current-limiting resistor R18 can effectively limit the size of the transient current, thereby protecting the second microcontroller U4 of the buck constant current module 400 from being damaged or appearing abnormal state due to excessive current impact.

[0048] As shown in the figure, Figure 1 and Figure 2As shown, in one embodiment, the input preprocessing module 100 includes an interference suppression circuit 110 and a first rectifier bridge circuit BD1. The input terminal of the interference suppression circuit 110 is connected to an external power supply terminal, and the output terminal of the interference suppression circuit 110 is connected to the input terminal of the first rectifier bridge circuit BD1. The output terminal of the first rectifier bridge circuit BD1 is connected to the first terminal of the energy storage boost inductor L2. In this embodiment, the main function of the interference suppression circuit 110 is to reduce or eliminate electromagnetic interference and surge current from the external power supply. When the external power supply terminal is connected to the circuit, a large surge current and electromagnetic interference may be generated due to the instantaneous operation of the power switch or when the load changes. If the surge current and electromagnetic interference directly enter the subsequent circuit, they will damage the components in the circuit and even affect the normal operation of the circuit. The inductor and capacitor components in the interference suppression circuit 110 can form a low-pass filter and effectively attenuate high-frequency electromagnetic interference. At the same time, the interference suppression circuit 110 also includes a varistor component, which can quickly conduct and clamp the voltage in the event of an overvoltage fault, thereby protecting the subsequent circuit from damage. The function of the first rectifier bridge circuit BD1 is to convert the AC power supplied by the external power source into DC power. When AC power is input, the rectifier bridge circuit can use the unidirectional conductivity of the diodes to convert both the positive and negative half-cycles of the AC power into DC power, and output it to the energy storage boost inductor L2.

[0049] like Figure 1 and Figure 6 As shown, in one embodiment, the voltage detection output module 500 includes an AC input voltage detection circuit 510 and a linear regulator circuit 520. The AC input voltage detection circuit 510 includes a second rectifier bridge circuit BD2, a second current-limiting resistor R13, and an optocoupler U3. The input terminal of the second rectifier bridge circuit BD2 is connected to the output terminal of the interference suppression circuit 110, and the output terminal of the second rectifier bridge circuit BD2 is connected to the first terminal of the second current-limiting resistor R13. The second terminal of the second current-limiting resistor R13 is connected to the input terminal of the optocoupler U3. The input terminal of the linear regulator circuit 520 is connected to the output terminal of the flyback converter module 300. The first terminal of the phototransistor of the optocoupler U3 and the power input terminal of the first microcontroller U5 are respectively connected to the output terminal of the linear regulator circuit 520. The second terminal of the phototransistor of the optocoupler U3 is connected to the voltage signal detection terminal I / O1 of the first microcontroller U5. In this embodiment, the function of the second rectifier bridge circuit BD2 is to convert AC power into DC power. The rectified DC power is transmitted to the input terminal of the optocoupler U3 through the second current limiting resistor R13. When the light-emitting diode in the optocoupler U3 receives the DC power signal, it will emit a light signal. Subsequently, the light signal is received by the phototransistor, which then turns on the phototransistor.

[0050] Specifically, since the first end of the opto-coupler U3 photo triode and the power input end of the first microcontroller U5 are respectively connected with the output end of the linear voltage stabilizing circuit 520, the second end of the opto-coupler U3 photo triode is connected with the voltage signal detection end I / O1 of the first microcontroller U5, when the alternating current input voltage of the external power supply flows through the second rectifier bridge circuit BD2, the photo triode is turned on, the linear voltage stabilizing circuit 520 obtains the electric energy from the output end of the flyback conversion module 300 and outputs the stable voltage to the voltage signal detection end I / O1 of the first microcontroller U5 and the power input end of the first microcontroller U5, so as to ensure that the first microcontroller U5 is in the normal working state. When the external power supply stops inputting the voltage, the second rectifier bridge has no voltage output, thus the opto-coupler U3 light emitting diode loses the electricity and the photo triode is cut off, so that the voltage signal detection end I / O1 of the first microcontroller U5 loses the voltage signal, and the first microcontroller U5 can judge the alternating current input voltage state of the external power supply in real time according to the received voltage signal, and then adjust the PWM signal output to the second microcontroller U4 in the step-down constant current module 400, so as to make the lighting load realize the working state of slow lightening or slow extinguishing.

[0051] As shown in Figure 1 and Figure 6 In one embodiment, the linear voltage stabilizing circuit 520 includes a first electronic switch tube Q1, a voltage stabilizing diode ZD1 and a first biasing resistor R24, the first end of the first electronic switch tube Q1 is connected with the output end of the flyback conversion module 300, the first end of the first biasing resistor R24 is connected with the first end of the first electronic switch tube Q1, the second end of the first biasing resistor R24 is connected with the control end of the first electronic switch tube Q1, the negative electrode of the voltage stabilizing diode ZD1 is connected with the control end of the first electronic switch tube Q1, the positive electrode of the voltage stabilizing diode ZD1 is grounded, and the second end of the first electronic switch tube Q1 is connected with the first end of the opto-coupler U3 photo triode. In this embodiment, the first end of the first electronic switch tube Q1 is connected with the output end of the flyback conversion module 300, and the flyback conversion module 300 transmits the electric energy to the first electronic switch tube Q1 after voltage conversion and adjustment. Since the first end of the first biasing resistor R24 is connected with the first end of the first electronic switch tube Q1, and the second end thereof is connected with the control end of the first electronic switch tube Q1, the biasing resistor provides the voltage for the control end of the first electronic switch tube Q1, so as to ensure that the first electronic switch tube Q1 is stably turned on or cut off in the normal working range. The voltage stabilizing diode ZD1 is connected in parallel between the control end of the first electronic switch tube Q1 and the ground, when the voltage of the control end exceeds the breakdown voltage thereof, the voltage stabilizing diode ZD1 is turned on, and the excess voltage is discharged to the ground, so as to ensure that the voltage of the control end of the first electronic switch tube Q1 is not too high, and thus the first electronic switch tube Q1 is protected from damage and the voltage of the control end of the first electronic switch tube Q1 is maintained stable.

[0052] As Figure 1 and Figure 4 shown, in one embodiment, the flyback conversion module 300 includes a transformer T1A and a secondary side rectifier diode D6. The input terminal of the transformer T1A is connected to the positive electrode of the electrolytic capacitor CE1, the output terminal of the transformer T1A is connected to the positive electrode of the secondary side rectifier diode D6, and the negative electrode of the secondary side rectifier diode D6 is connected to the input terminal of the step-down constant current module 400. In this embodiment, when the primary coil current of the transformer T1A is interrupted, the energy stored in the magnetic core of the transformer T1A needs to be released through the secondary coil. At this time, the secondary side rectifier diode D6 is turned on, providing a return path for the current in the secondary coil of the transformer T1A, ensuring the continuity and stability of the current. At the same time, the secondary coil will generate a reverse voltage when the switch tube is turned off, and the secondary side rectifier diode D6 can limit the reverse voltage through its unidirectional conduction characteristic, thereby avoiding damage to circuit components caused by reverse voltage.

[0053] As Figure 1 and Figure 7 shown, in one embodiment, the single-chip microcomputer control module 600 further includes a second filter capacitor C10, the first end of the second filter capacitor C10 is connected to the power supply terminal VDD of the first microcontroller U5, and the second end of the second filter capacitor C10 is grounded. In this embodiment, the second filter capacitor C10 is connected in parallel between the power supply terminal VDD of the first microcontroller U5 and the ground, forming a low-pass filter circuit. Since the capacitor has a low impedance to high-frequency noise and voltage fluctuations, when transient changes occur in the supply voltage, the second filter capacitor C10 can quickly absorb or release charges, thereby bypassing high-frequency noise to the ground, reducing their impact on the supply voltage of the first microcontroller U5. In this way, the second filter capacitor C10 can effectively smooth the supply voltage, reduce voltage fluctuations, and provide stable voltage for the first microcontroller U5.

[0054] The application also provides a lighting lamp comprising the gradual lighting switch control circuit 10 of any one of the embodiments. In the embodiment, the input preprocessing module 100 comprises an anti-interference filter, a surge protection circuit and a rectifier circuit. When the switch is closed, the external power supply outputs a current, which is first processed by the input preprocessing module 100 to remove electromagnetic interference or surge current, and then transmitted to the rectifier circuit in the input preprocessing module 100, which converts the alternating current into direct current. Further, the rectified and filtered direct current is transmitted to the energy storage boost inductor L2 of the boost conversion module 200. At this time, the current passes through the energy storage boost inductor L2, and then the current is conducted to the boost controller U1, which controls the charging and discharging time of the electrolytic capacitor CE1 by setting the conduction duty cycle of the switching device in the boost controller U1. The electrolytic capacitor CE1 acts as an energy storage element and provides a stable direct current power supply for the flyback converter. Then, the flyback converter module further adjusts the voltage and transmits the electrical energy to the step-down constant current module 400. Since the PWM signal output end of the first microcontroller U5 of the single-chip microcomputer control module 600 is connected to the PWM signal receiving end of the step-down constant current module 400, the output current of the step-down constant current module 400 is controlled by the PWM signal output by the first microcontroller U5, so that the load module obtains a gradually changing output current, and the lighting load is in a slow brightening state during the lighting process. Specifically, when the main switch in the circuit is closed, the lighting load enters the slow brightening process, and the voltage detection output module 500 detects that the external power supply end is in a normal power supply state, and at the same time, the voltage detection output module 500 transmits the voltage signal to the first microcontroller U5 of the single-chip microcomputer control module 600 through the internal photoelectric coupler U3. At this time, the first microcontroller U5 outputs a gradually increasing PWM duty cycle signal to the PWM signal receiving end of the step-down constant current module 400 according to the detected voltage signal, so that the current output by the step-down constant current module 400 to the load gradually increases from small to large, and the lighting load realizes the slow brightening process during the lighting process. The first dial switch SW3 and the second dial switch SW4 can be used to adjust the slow brightening time of the lighting load during the lighting process. For example, in one setting mode of the first microcontroller U5, the first dial switch SW3 is closed, which can increase the time of the slow brightening process, i.e., the time from the closing of the lighting load to the complete brightening will be prolonged; and the second dial switch SW4 is closed, which can further increase the time of the slow brightening process, and the second dial switch SW4 and the first dial switch SW3 are closed at the same time, which can achieve the cumulative effect of increasing the slow brightening time. Conversely, when the first dial switch SW3 is open, the time of the slow brightening process can be reduced, i.e., the time from the closing of the lighting load to the complete brightening will be shortened compared to when the first dial switch SW3 is closed; similarly, when the second dial switch SW4 is open, the time of the slow brightening process can be further shortened.Further, in another setting mode of the first microcontroller U5, the first dial switch SW3 is closed, the time from the lighting load being off to fully on can be reduced; while the second dial switch SW4 is closed, the time of the dimming process can be further reduced; on the contrary, when the first dial switch SW3 is open, the time of the dimming process can be increased, i.e. the time from the lighting load being off to fully on will be prolonged compared to when the first dial switch SW3 is closed; similarly, when the second dial switch SW4 is open, the time of the dimming process can be further increased. Thus, the user can set the time of the dimming process of the lighting load according to his own needs, thereby improving the flexibility of the gradual lighting switch control circuit 10. Further, when the main switch in the circuit is open, the lighting load enters the dimming process, and the input preprocessing module 100 and the boost converter module 200 are in a stopped working state. At this time, the electrolytic capacitor CE1 starts to discharge, and since the capacity of the electrolytic capacitor CE1 is large enough, it can continue to provide voltage to the flyback converter for a period of time, so that the flyback converter can still work for a period of time, and thus the step-down constant current module 400 can still output current to the load. At the same time, since the voltage detection output module 500 detects that the input preprocessing module 100 does not output a voltage signal, and the voltage signal detection end I / O1 of the first microcontroller U5 is connected to the voltage signal output end of the voltage detection output module 500, the voltage signal detection end I / O1 of the first microcontroller U5 loses the voltage signal, thereby driving the PWM signal output end of the first microcontroller U5 to output a gradually decreasing PWM duty cycle signal to the PWM signal receiving end of the step-down constant current module 400, thereby controlling the current output by the step-down constant current module 400 to the load to gradually decrease, to achieve the effect of gradually decreasing the brightness of the lighting load.

[0055] Compared with the prior art, the present disclosure has at least the following advantages:

[0056] 1. The gradual lighting switch control circuit 10 described above, since the boost converter module 200 is used, when the input current changes due to the electrolytic capacitor CE1, the boost converter module 200 can quickly adjust the harmonic content of the current to maintain synchronization with the input current waveform, so that the harmonic current actively follows the input current waveform for correction, and even if the capacity of the electrolytic capacitor CE1 increases, the requirements for harmonic current in the existing standard documents can still be met.

[0057] 2. On the other hand, the first microcontroller U5 outputs a gradual PWM duty cycle signal to the step-down constant current module 400, thereby accurately controlling the current output by the step-down constant current module 400 to the lighting load, and thereby achieving the effect of gradually turning on the lighting load and gradually turning off the lighting load.

[0058] 3. Furthermore, the dimming time of the lighting load in the process of turning on the light can be adjusted by the first dial switch SW3 and the second dial switch SW4, thereby improving the flexibility of the gradual lighting switch control circuit 10.

[0059] The above-described embodiments only express several implementation manners of the present disclosure, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the disclosed patent. It should be noted that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure patent should be subject to the appended claims.

Claims

1. A gradual lighting switch control circuit, comprising an input preprocessing module, a flyback conversion module and a step-down constant current module, characterized in that, The boost conversion module, the voltage detection output module and the single-chip microcomputer control module are further included, The input end of the input preprocessing module is used for being connected with an external power supply end, the output end of the input preprocessing module is connected with the input end of the boost conversion module, the output end of the boost conversion module is connected with the input end of the flyback conversion module, the output end of the flyback conversion module is respectively connected with the input end of the step-down constant current module and the voltage stabilization input end of the voltage detection output module, and the output end of the step-down constant current module is used for providing electric energy for a lighting load. The boost conversion module includes a boost controller, an energy storage boost inductor, a freewheeling diode and an electrolytic capacitor, the first end of the energy storage boost inductor is connected with the output end of the input preprocessing module, the second end of the energy storage boost inductor is respectively connected with the anode of the freewheeling diode and the switch control end of the boost controller, the cathode of the freewheeling diode is connected with the anode of the electrolytic capacitor, the anode of the electrolytic capacitor is connected with the input end of the flyback conversion module, and the cathode of the electrolytic capacitor is grounded. The single-chip microcomputer control module includes a first microcontroller, a first voltage dividing resistor, a second voltage dividing resistor, a first DIP switch and a second DIP switch, the power supply end of the first microcontroller is connected with the voltage stabilization output end of the voltage detection output module, one end of the first DIP switch is connected with the first switch signal end of the first microcontroller through the first voltage dividing resistor, one end of the second DIP switch is connected with the second switch signal end of the first microcontroller through the second voltage dividing resistor, the other end of the first DIP switch and the other end of the second DIP switch are respectively connected with the power supply end of the first microcontroller, the voltage signal detection end of the first microcontroller is connected with the voltage signal output end of the voltage detection output module, the PWM signal output end of the first microcontroller is connected with the PWM signal receiving end of the step-down constant current module, and the voltage signal input end of the voltage detection output module is connected with the external power supply end.

2. The progressive lighting switch control circuit of claim 1, wherein, The step-down constant current module includes a second microcontroller, a third voltage dividing resistor, a fourth voltage dividing resistor, a third DIP switch and a fourth DIP switch, the first end of the third DIP switch is connected with the first end of the fourth DIP switch, the second end of the third DIP switch is connected with the digital input end of the second microcontroller through the third voltage dividing resistor, the second end of the fourth DIP switch is connected with the digital input end of the second microcontroller through the fourth voltage dividing resistor, the first end of the third DIP switch is connected with the power supply end of the second microcontroller, the power supply end of the second microcontroller is connected with the output end of the flyback conversion module, the output end of the second microcontroller is used for being connected with a load module, and the PWM signal receiving end of the second microcontroller is connected with the PWM signal output end of the first microcontroller.

3. The progressive lighting switch control circuit of claim 2, wherein, The voltage reduction constant current module further comprises a first current limiting resistor, a first end of the first current limiting resistor is connected with a PWM signal output end of the first microcontroller, and a second end of the first current limiting resistor is connected with a PWM signal receiving end of the second microcontroller.

4. The progressive lighting switch control circuit of claim 2, wherein, The voltage reduction constant current module further comprises a first filter capacitor, a first end of the first filter capacitor is connected with the PWM signal receiving end of the second microcontroller, and a second end of the first filter capacitor is grounded.

5. The progressive lighting switch control circuit of claim 1, wherein, The input pretreatment module comprises an interference suppression circuit and a first rectifier bridge circuit, an input end of the interference suppression circuit is connected with an external power supply end, an output end of the interference suppression circuit is connected with an input end of the first rectifier bridge circuit, and an output end of the first rectifier bridge circuit is connected with a first end of the energy storage voltage boosting inductor.

6. The progressive lighting switch control circuit of claim 5, wherein, The voltage detection output module comprises an alternating current input voltage detection circuit and a linear voltage stabilizing circuit, the alternating current input voltage detection circuit comprises a second rectifier bridge circuit, a second current limiting resistor and a photoelectric coupler, an input end of the second rectifier bridge circuit is connected with the output end of the interference suppression circuit, an output end of the second rectifier bridge circuit is connected with a first end of the second current limiting resistor, a second end of the second current limiting resistor is connected with an input end of the photoelectric coupler, an input end of the linear voltage stabilizing circuit is connected with an output end of the flyback conversion module, a first end of a photoelectric coupler phototriode and a power supply input end of the first microcontroller are respectively connected with an output end of the linear voltage stabilizing circuit, and a second end of the photoelectric coupler phototriode is connected with a voltage signal detection end of the first microcontroller.

7. The progressive lighting switch control circuit of claim 6, wherein, The linear voltage stabilizing circuit comprises a first electronic switch tube, a voltage stabilizing diode and a first bias resistor, a first end of the first electronic switch tube is connected with the output end of the flyback conversion module, a first end of the first bias resistor is connected with the first end of the first electronic switch tube, a second end of the first bias resistor is connected with a control end of the first electronic switch tube, a negative electrode of the voltage stabilizing diode is connected with the control end of the first electronic switch tube, a positive electrode of the voltage stabilizing diode is grounded, and a second end of the first electronic switch tube is connected with the first end of the photoelectric coupler phototriode.

8. The progressive lighting switch control circuit of claim 1, wherein, The flyback conversion module comprises a transformer and a secondary side rectification diode, an input end of the transformer is connected with a positive electrode of the electrolytic capacitor, an output end of the transformer is connected with a positive electrode of the secondary side rectification diode, and a negative electrode of the secondary side rectification diode is connected with an input end of the voltage reduction constant current module.

9. The progressive lighting switch control circuit of claim 1, wherein, The single-chip microcomputer control module further comprises a second filter capacitor, a first end of the second filter capacitor is connected with a power supply end of the first microcontroller, and a second end of the second filter capacitor is grounded.

10. A lighting fixture, characterized by, The gradual change type lighting switch control circuit comprises the gradual change type lighting switch control circuit according to any one of claims 1 to 9.

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