A linear constant current control circuit and light source system

Abstract

A linear constant current control circuit and a light source system, the linear constant current control circuit comprising: a rectifier component, a constant current control component and an energy storage component; the rectifier component rectifies the AC signal output by the AC power supply to obtain a DC signal; when the voltage of the DC signal is greater than a preset voltage, the constant current control component adjusts the input current of the light-emitting component according to the voltage change of the DC signal; when the voltage of the DC signal is less than or equal to the preset voltage, the energy storage component outputs a discharge current; the constant current control component performs current limiting processing on the discharge current to make the output current of the light-emitting component constant; this embodiment enables the light-emitting component to always maintain a constant current output at any time, and the output current of the light-emitting component is flicker-free and will not cause visual fatigue to the human eye.

Description

Technical Field

[0001] The present application belongs to the field of light source driving technology, and in particular, relates to a linear constant current control circuit and a light source system. Background Art

[0002] At present, LED (Light Emitting Diode) lighting products have been widely used in people's lives. In the process of driving and controlling LED products, people mainly adopt the following two methods. One is to control the output current of LED lighting products to remain constant so that LED lighting products can achieve a flicker-free function. This control method will make the power factor of the line network input of LED products poor, and its power factor is usually only 0.5 or lower; the other is to improve the power factor of the line network input. This control method will make the output current of LED products fluctuate and cannot work under constant current drive. LED products will flicker, and human eyes will produce visual fatigue after looking at them for a long time, which is not good for human health.

[0003] Therefore, in the process of controlling LED products, traditional technical solutions are not compatible with high power factor and flicker-free functions, which reduces the visual effect of users. Summary of the invention

[0004] The purpose of the present application is to provide a linear constant current control circuit and a light source system, aiming to solve the problem that the traditional LED control circuit is not compatible with high power factor and no flicker.

[0005] A first aspect of an embodiment of the present application provides a linear constant current control circuit connected to a light-emitting component, wherein the light-emitting component includes at least one light-emitting module connected in series, and the linear constant current control circuit includes:

[0006] A rectifier component connected to an AC power source and used to rectify the AC signal output by the AC power source to obtain a DC signal;

[0007] A constant current control component connected to the rectifying component and the light emitting component, and used for adjusting the input current of the light emitting component according to the voltage variation of the DC signal when the voltage of the DC signal is greater than a preset voltage; and

[0008] An energy storage component connected to the rectifying component, the constant current control component and the light-emitting component, and configured to output a discharge current when the voltage of the DC signal is less than or equal to the preset voltage;

[0009] The constant current control component is also used to limit the discharge current so as to make the output current of the light-emitting component constant.

[0010] In one embodiment, the constant current control component includes:

[0011] A first constant current control component connected to the rectifying component, the energy storage component and the light-emitting component, configured to output a first preset current when the voltage of the DC signal is greater than a first preset voltage and less than or equal to a second preset voltage, and to limit the discharge current and output a second preset current when the voltage of the DC signal is less than or equal to the first preset voltage; and

[0012] connected to the energy storage component, the first constant current control component and the light-emitting component, and used for outputting the preset step current corresponding to the light-emitting module to the second constant current control component of the light-emitting component when the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module;

[0013] Wherein, the conduction voltage of each of the light-emitting modules is greater than or equal to the second preset voltage.

[0014] In one embodiment, the energy storage component includes:

[0015] At least one energy storage component, each of which is connected to each of the light-emitting modules in a one-to-one correspondence, and each of which is connected to the first constant current control component, the second constant current control component and the rectifying component;

[0016] Each of the energy storage components is used to charge when the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module, and output the discharge current when the voltage of the DC signal is less than or equal to the first preset voltage.

[0017] In one embodiment, each of the energy storage components comprises:

[0018] A first diode, a second diode and a first capacitor;

[0019] The first end of the first capacitor is connected to the first constant current control component and the rectifier component, the anode of the first diode and the cathode of the second diode are connected to the second end of the first capacitor, the cathode of the first diode is connected to the second constant current control component, and the anode of the second diode is connected to the corresponding light-emitting module.

[0020] In one embodiment, the first constant current control component includes:

[0021] A constant current source connected to the rectifying component and the energy storage component, and configured to be turned on when the voltage of the DC signal is less than or equal to the second preset voltage to output the DC signal or the discharge current; and

[0022] A current processor connected to the constant current source, the second constant current control component and the light-emitting component, and used for limiting the current of the DC signal or the discharge current.

[0023] In one embodiment, the constant current source includes: an operational amplifier and a first switch tube;

[0024] The positive input terminal of the operational amplifier is used to connect to the first reference power supply, the output terminal of the operational amplifier is connected to the control terminal of the first switch tube, the first conduction terminal of the first switch tube is connected to the rectifier component and the energy storage component, and the second conduction terminal of the first switch tube and the negative input terminal of the operational amplifier are connected to the current processor.

[0025] In one embodiment, the current processor includes: a first resistor and a second resistor;

[0026] The first end of the first resistor is connected to the constant current source, the second end of the first resistor and the first end of the second resistor are commonly connected to the second constant current control component, and the second end of the second resistor is connected to the light-emitting component.

[0027] In one embodiment, it also includes:

[0028] A flicker elimination component is connected to the light-emitting component, the first constant current control component and the second constant current control component, and is used to eliminate the flicker of the light-emitting component.

[0029] In one embodiment, when the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module and the voltage of the DC signal increases, the preset step current connected to the light-emitting component increases;

[0030] When the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module and the voltage of the DC signal decreases, the preset step current connected to the light-emitting component decreases.

[0031] A second aspect of an embodiment of the present application provides a light source system, comprising: a linear constant current control circuit and a light-emitting component as described above, wherein the linear constant current control circuit is connected to the light-emitting component, wherein the light-emitting component comprises at least one light-emitting module connected in series.

[0032] Compared with the conventional technology, the embodiments of the present application have the following beneficial effects: the above-mentioned linear constant current control circuit adjusts the input current of the light-emitting component according to the input voltage change of the light-emitting component through the constant current control component, so that the change amplitude of the input current of the light-emitting component follows the input voltage change, thereby improving the input power factor of the light-emitting component, and the discharge current of the energy storage component can make the output current of the light-emitting component constant, so as to achieve the effect of no flicker of the light-emitting module; when the light source of the light-emitting component is controlled by the present embodiment, when the voltage of the AC signal changes, the current control mode of the light-emitting component is changed respectively, thereby achieving the two functions of no flicker and high power factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of the structure of a linear constant current control circuit provided in one embodiment of the present application;

[0034] Figure 2 A schematic diagram of the structure of a constant current control component and an energy storage component provided in one embodiment of the present application;

[0035] Figure 3 A schematic diagram of the circuit structure of an energy storage component provided in one embodiment of the present application;

[0036] Figure 4 A schematic diagram of the circuit structure of a first constant current control component provided in an embodiment of the present application;

[0037] Figure 5 A schematic diagram of the circuit structure of a constant current source provided in one embodiment of the present application;

[0038] Figure 6 A schematic diagram of the circuit structure of a current processor provided in one embodiment of the present application;

[0039] Figure 7 A schematic diagram of a voltage waveform of an AC signal and a current waveform of a light-emitting component provided in an embodiment of the present application;

[0040] Figure 8 A schematic diagram of a complete current waveform of a light-emitting component provided in an embodiment of the present application;

[0041] Fig. 9 A schematic diagram of another complete current waveform of a light-emitting component provided in an embodiment of the present application;

[0042] Fig.10 Another structural schematic diagram of a linear constant current control circuit provided in one embodiment of the present application;

[0043] Fig.11 A schematic diagram of the structure of a light source system provided in one embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0045] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0046] Figure 1 The structure diagram of the linear constant current control circuit 10 provided in the preferred embodiment of the present application is shown. The linear constant current control circuit 10 is connected to the light-emitting component 20. The light-emitting component 20 includes at least one light-emitting module connected in series, wherein each light-emitting module includes any one of the three light beads, the blue light beads, the red light beads and the green light beads. The light-emitting component 20 is driven by the linear constant current control circuit 10 to emit a light source of a preset color and a preset brightness. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0047] The linear constant current control circuit 10 comprises: a rectifying component 101 , a constant current control component 102 and an energy storage component 103 .

[0048] The rectifier assembly 101 is connected to an AC power source and is used to rectify an AC signal output by the AC power source to obtain a DC signal.

[0049] Optionally, the AC power supply is mains electricity, and the voltage of the AC signal shows a preset change pattern over time; for example, the voltage waveform of the AC signal follows a sine wave or a cosine wave; after the AC signal is rectified by the rectifier component 101, a DC signal with a preset current / voltage can be output.

[0050] The constant current control component 102 is connected to the rectifying component 101 and the light emitting component 20 and is used to adjust the input current of the light emitting component 20 according to the voltage variation of the DC signal when the voltage of the DC signal is greater than a preset voltage.

[0051] Among them, the preset voltage is set in advance. When the voltage of the DC signal is greater than the preset voltage, the constant current control component 102 adjusts the input current of the light-emitting component 20 so that the input current change amplitude of the light-emitting component 20 follows the input voltage change of the light-emitting component 20, thereby improving the power factor of the light-emitting component 20; and when the constant current control component 102 adjusts the input current of the light-emitting component 20 according to the voltage change of the DC signal, the output current of the light-emitting component 20 can be equivalent to a certain set value, and has a flicker-free current output characteristic.

[0052] The energy storage component 103 is connected to the rectifying component 101 , the constant current control component 102 and the light emitting component 20 , and is used to output a discharge current when the voltage of the DC signal is less than or equal to a preset voltage.

[0053] The energy storage component 103 can realize the discharge function and the charging function; when the voltage of the DC signal is less than or equal to the preset voltage, the constant current control component 102 cannot be started by the DC signal. At this time, the energy storage component 103 discharges to continue to supply power to the light-emitting component 20.

[0054] The constant current control component 102 is also used to limit the discharge current so that the output current of the light-emitting component 20 is constant.

[0055] When the energy storage component 103 discharges, the energy storage component 103, the constant current control component 102 and the light-emitting component 20 form a discharge circuit, and after the current limiting processing of the constant current control component 102, the output current of the light-emitting component 20 is equal to the preset value, so that the light-emitting component 20 can achieve a flicker-free function; within the full cycle range of the voltage change of the AC signal, the output current of the light-emitting component 20 is constant, and the light-emitting component 20 has no flicker, which improves the light source quality of the light-emitting component 20.

[0056] As an optional implementation, Figure 2 The structure of the constant current control component 102 and the energy storage component 103 provided in this embodiment is shown. Figure 2 The constant current control component 102 includes: a first constant current control component 1021 and a second constant current control component 1022; the first constant current control component 1021 is connected to the rectifying component 101, the energy storage component 102 and the light-emitting component 20, and is used to output a first preset current when the voltage of the DC signal is greater than the first preset voltage and less than or equal to the second preset voltage, and to limit the discharge current and output the second preset current when the voltage of the DC signal is less than or equal to the first preset voltage.

[0057] In this embodiment, the second preset voltage is greater than the first preset voltage.

[0058] When the voltage of the DC signal is greater than the first preset voltage, the DC signal can drive the first constant current control component 1021 to achieve normal circuit function, and the DC signal is current limited by the first constant current control component 1021 to output the first preset current so that the output current of each light-emitting module is constant; when the voltage of the DC signal is less than or equal to the first preset voltage, the energy storage component 103 discharges, and drives the first constant current control component 1021 through the discharge current to achieve normal circuit function, and the output current of the light-emitting component 20 is constant.

[0059] Preferably, the first preset current and the second preset current are equal; when the voltage of the AC signal changes, the output current of the light-emitting component 20 remains unchanged, achieving an output without flickering.

[0060] The second constant current control component 1022 is connected to the energy storage component 103, the first constant current control component 1021 and the light-emitting component 20, and is used to output the preset step current corresponding to the light-emitting module to the light-emitting component 20 when the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module.

[0061] Wherein, the conduction voltage of each light-emitting module is greater than or equal to the second preset voltage.

[0062] The light-emitting component 20 includes at least one light-emitting module connected in series. When the voltage of the AC signal continues to rise, the voltage of the DC signal also rises; when the voltage of the AC signal continues to drop, the voltage of the DC signal continues to drop; wherein the on-state voltage of each light-emitting module rises in sequence in the order of series arrangement, and when the voltage of the DC signal is successively greater than the on-state voltage of the corresponding light-emitting module, the second constant current control component 1022 generates a preset step current to supply constant current to the light-emitting component 20; when the voltage of the DC signal is greater than the second preset voltage, a preset step current with a preset amplitude is output to the light-emitting component 20, and the preset step current output by the second constant current control component 1022 will cause the first constant current control component 1021 to be closed, and the first constant current control component 1021 cannot output current.

[0063] When the voltage of the DC signal is greater than the second preset voltage and each light-emitting module is turned on in turn, the preset step current corresponding to the light-emitting module will increase or decrease with the voltage of the DC signal, and the input current of the light-emitting component 20 will change with the voltage of the AC signal. Moreover, when the number of light-emitting modules included in the light-emitting component 20 is more, the change trend of the input current of the light-emitting component 20 is more consistent with the voltage change trend of the DC signal, and the power factor input to the light-emitting component 20 is higher, thereby realizing the constant current control function of the light-emitting component 20 with a high power factor.

[0064] As an optional implementation, when the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module and the voltage of the DC signal increases, the preset step current connected to the light-emitting component 20 increases.

[0065] When the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module and the voltage of the DC signal decreases, the preset step current connected to the light-emitting component 20 decreases.

[0066] In this embodiment, when each light-emitting module is turned on in turn, the change trend of the preset step current output by the second constant current control component 1022 is consistent with the change trend of the voltage of the AC signal, thereby improving the power factor input to the light-emitting component 20.

[0067] As an alternative implementation, see Figure 2 , the energy storage assembly 103 includes: at least one energy storage component ( Figure 2 Represented by 1031, ..., 103N, where N is an integer greater than 0), each energy storage component is connected to each light-emitting module in a one-to-one correspondence, and each energy storage component is connected to the first constant current control component 1021, the second constant current control component 1022 and the rectifying component 101.

[0068] Each energy storage component is used to charge when the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module, and output a discharge current when the voltage of the DC signal is less than or equal to the first preset voltage.

[0069] When the voltage of the DC signal is greater than the conduction voltage of the corresponding light-emitting module, the light-emitting module is turned on, the charging circuit of the corresponding energy storage component is turned on, the energy storage component is charged by the DC signal, and the amount of electricity stored in the energy storage component increases, ready for a discharge operation.

[0070] When the voltage of the DC signal is less than or equal to the first preset voltage, the DC signal cannot start the first constant current control component 1021 and the second constant current control component 1022, and both the first constant current control component 1021 and the second constant current control component 1022 stop, and the energy storage component, the first constant current control component 1021 and the light-emitting component 20 form a discharge circuit, and after the discharge current is limited by the first constant current control component 1021, the light-emitting component 20 is connected to the second preset current; in the discharge stage of the energy storage component, the input current of the light-emitting component 20 can still be constant, thereby realizing flicker-free control of the light-emitting component 20.

[0071] As an optional implementation, Figure 3 The circuit structure of the energy storage component provided in this embodiment is shown in FIG. Figure 3 , the energy storage component includes: a first diode D1, a second diode D2 and a first capacitor C1.

[0072] The first end of the first capacitor C1 is connected to the first constant current control component 1021 and the rectifier component 101, the anode of the first diode D1 and the cathode of the second diode D2 are connected to the second end of the first capacitor C1, the cathode of the first diode D1 is connected to the second constant current control component 1022, and the anode of the second diode D2 is connected to the corresponding light-emitting module.

[0073] In this embodiment, the second diode D2 can prevent voltage backflow; when the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module, the corresponding first diode D1 is turned on and the first capacitor C1 is charged.

[0074] As an optional implementation, Figure 4 FIG. 1 shows a schematic diagram of the circuit structure of the first constant current control component 1021 provided in this embodiment. Figure 4 The first constant current control component 1021 includes: a constant current source 401 and a current processor 402; the constant current source 401 is connected to the rectifier component 101 and the energy storage component 103, and is used to be turned on when the voltage of the DC signal is less than or equal to the second preset voltage, and output a DC signal or a discharge current.

[0075] Specifically, when the voltage of the DC signal is greater than the first preset voltage and less than or equal to the second preset voltage, the constant current source 401 is directly turned on by the DC signal, and the constant current source 401 outputs the DC signal; when the voltage of the DC signal is less than or equal to the first preset voltage, the constant current source 401 is turned on by the discharge current, and the constant current source 401 outputs the discharge current.

[0076] The current processor 402 is connected to the constant current source 401, the second constant current control component 1022 and the light-emitting component 20, and is used to limit the current of the DC signal or the discharge current.

[0077] After the current processor 402 performs current limiting processing on the current or discharge current of the DC signal, the current processor 402 outputs the first preset current or the second preset current to the light-emitting component 20 to perform constant current control on the light-emitting component 20, and the output current of the light-emitting component 20 is flicker-free.

[0078] As an optional implementation, Figure 5 The circuit structure of the constant current source 401 provided in this embodiment is shown in FIG. Figure 5 The constant current source 401 includes: an operational amplifier INV1 and a first switch tube Q1.

[0079] The positive input terminal of the operational amplifier INV1 is used to connect to the first reference power supply, wherein the first reference power supply is used to output a first preset voltage; the output terminal of the operational amplifier INV1 is connected to the control terminal of the first switch tube Q1, the first conduction terminal of the first switch tube Q1 is connected to the rectifier component 101 and the energy storage component 103, and the second conduction terminal of the first switch tube Q1 and the negative input terminal of the operational amplifier INV1 are connected to the current processor 402.

[0080] Optionally, the first switch tube Q1 is a MOS tube or a triode; for example, the first switch tube Q1 is an NMOS tube, the gate of the NMOS tube is the control end of the first switch tube Q1, the drain of the NMOS tube is the first conduction end of the first switch tube Q1, and the source of the NMOS tube is the second conduction end of the first switch tube Q1.

[0081] As an optional implementation, Figure 6 The circuit structure of the current processor 402 provided in this embodiment is shown in FIG. Figure 6 , the current processor 402 includes: a first resistor R1 and a second resistor R2.

[0082] A first end of the first resistor R1 is connected to the constant current source 401 , a second end of the first resistor R1 and a first end of the second resistor R2 are commonly connected to the second constant current control component 1022 , and a second end of the second resistor R2 is connected to the light emitting component 20 .

[0083] When the constant current source 401 outputs a DC signal or a discharge current, the first resistor R1 and the second resistor R2 are combined to limit the current of the DC signal or the discharge current; when the voltage of the DC signal is greater than the second preset voltage, the constant current source 401 is in a stopped state, and the second constant current control component 1022 outputs a preset step current. The second constant current control component 1022, the second resistor R2 and the light-emitting component 20 form a current loop, and the preset step current is limited by the second resistor R2. The light-emitting component 20 can achieve flicker-free constant current control at any time.

[0084] In order to illustrate the working principle of the linear constant current control circuit 10 in this embodiment, the following is combined with the attached Figure 1 and attached Figure 6 , explained through a specific application scenario, as follows:

[0085] In this application scenario, the voltage of the light emitting component 20 is less than or equal to half of the voltage amplitude of the DC signal, that is, Wherein VH is the voltage of the light emitting component 20, and Vac is the voltage peak value of the AC signal.

[0086] See also Figure 7(a), when the voltage of the DC signal is greater than the first preset voltage, the first constant current control component 1021 starts to work; when the voltage of the DC signal rises from the first preset voltage to the second preset voltage, as shown in Figure 7 As shown in (b), the DC signal charges the first capacitor C1 through the first diode D1. At this time, the first diode D1, the first capacitor C1, the second constant current control component 1022 and the light-emitting component 20 form a working loop, and the current generated by the second constant current control component 1022 turns off the first constant current control component 1021.

[0087] When the voltage of the DC signal continues to rise from the second preset voltage to the peak voltage, and then drops from the peak voltage to the second preset voltage, the voltage on the energy storage component is insufficient to maintain the second constant current control component 1022 to continue to turn on and reopen the first constant current control component 1021. The working circuit between the first constant current control component 1021 and the light-emitting component 20 is normal, and the first constant current control component 1021 works normally. Within one cycle of the AC signal, the working current waveforms of the first constant current control component 1021 and the second constant current control component 1022 are as follows: Figure 7 (a) and Figure 7 (b) as shown.

[0088] When the voltage of the DC signal is less than or equal to the first preset voltage, the DC signal cannot drive the first constant current control component 1021 to work. Figure 3 The first capacitor C1 in the light emitting component 20 is used as an energy storage device, and a discharge circuit is formed through the first constant current control component 1021, the corresponding light emitting module and the second diode D2. When the voltage of the DC signal drops to less than or equal to the first preset voltage, until the voltage of the DC signal is greater than the first preset voltage again, the current waveform of the light emitting component 20 is as follows: Figure 7 As shown in (c), at this time, after the discharge current is limited by the current processor 402, the light-emitting component 20 is driven with a constant current.

[0089] During a voltage cycle of an AC signal, Figure 7 (a) Figure 7 (b) Figure 7 (c) The current waveforms on the light emitting components 20 work in turns, and the complete current waveform on the light emitting components 20 is as follows: Figure 6 As shown, when setting Figure 7 (b) The preset step current waveform on the figure is as close to or equal to Figure 7 When the first preset current is used in (a), the current on the light-emitting component 20 is approximately a fixed current value; the light-emitting component 20 always maintains a constant current output at any time, and the output current has no flicker and will not cause visual fatigue to the human eye.

[0090] It should be noted that the above application scenario is applicable to the scenario where the light emitting assembly 20 includes only one light emitting module connected in series; if the light emitting assembly 20 includes multiple light emitting modules connected in series, Figure 8 The complete waveform of the current on the light emitting component 20 is shown when the light emitting component 20 includes two light emitting modules connected in series in this embodiment; Fig. 9 The complete waveform of the current on the light emitting component 20 is shown in FIG. 1 when the light emitting component 20 includes three light emitting modules connected in series; Figure 8 and attached Fig. 9 If the input current waveform of the light emitting component 20 is a two-stage preset step current, or when the input current waveform of the light emitting component 20 is a three-stage or four-stage current waveform, or a current waveform with more steps, the input current of the light emitting component 20 follows the input voltage change trend more obviously, and the input power factor characteristic of the light emitting component 20 will be better at this time; Figure 3 The multiple first capacitors C1 in the circuit can output a discharge current through the corresponding first capacitor C1 through the discharge circuit when the voltage of the AC signal is low, so that the output current of the light-emitting component 20 is constant, achieving the effect of output without flicker. The specific principles and steps are the same as those of FIG. Figure 7 The scene is similar to that in , so I won’t repeat it here.

[0091] As an optional implementation, Fig.10 Another structural schematic diagram of the linear constant current control circuit 10 provided in this embodiment is shown. Figure 1 The structure of the linear constant current control circuit 10 is shown in FIG. Fig.10 The linear constant current control circuit 10 further includes: a flicker elimination component 104, wherein the flicker elimination component 104 is connected to the light-emitting component 20, the first constant current control component 1021 and the second constant current control component 1022, and is used to eliminate the flicker of the light-emitting component 20.

[0092] Exemplarily, the flicker elimination component 104 includes at least one second capacitor, wherein a first terminal of the second capacitor is connected to a first terminal of the light-emitting component 20 , a first constant current control component 1021 and a second constant current control component 1022 , and a second terminal of the second capacitor is connected to a second terminal of the light-emitting component 20 .

[0093] As described above, when the second constant current control component 1022 adjusts the input current of the light-emitting component 20, the changing waveform of the preset step current output by the second constant current control component 1022 cannot be approximated by the changing waveform of the input voltage, and the light-emitting component 20 still has a slight flicker. By connecting at least one second capacitor in parallel to the light-emitting component 20, the flicker of the light-emitting component 20 can be further reduced, thereby improving the constant current control quality of the light-emitting component 20.

[0094] Fig.11The structure of the light source system 110 provided in this embodiment is shown in FIG. Fig.11 The light source system 110 includes: the linear constant current control circuit 10 and the light emitting component 20 as described above, the linear constant current control circuit 10 is connected to the light emitting component 20, wherein the light emitting component 20 includes at least one light emitting module connected in series; Figures 1 to 10 In the embodiment, the linear constant current control circuit 10 is used to perform constant current control on the light emitting component 20, which is compatible with the functions of high power factor and no flicker, improves the light source quality of the light source system 110, and has a wide range of applications.

[0095] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A linear constant current control circuit connected to a light-emitting component, wherein the light-emitting component comprises at least one light-emitting module connected in series, characterized in that: The linear constant current control circuit comprises: A rectifier component connected to an AC power source and used to rectify the AC signal output by the AC power source to obtain a DC signal; A constant current control component connected to the rectifying component and the light emitting component, and used for adjusting the input current of the light emitting component according to the voltage variation of the DC signal when the voltage of the DC signal is greater than a preset voltage; and An energy storage component connected to the rectifying component, the constant current control component and the light-emitting component, and configured to output a discharge current when the voltage of the DC signal is less than or equal to the preset voltage; The constant current control component is also used to limit the discharge current so that the output current of the light-emitting component is constant; The constant current control component comprises: A first constant current control component connected to the rectifying component, the energy storage component and the light-emitting component, configured to output a first preset current when the voltage of the DC signal is greater than a first preset voltage and less than or equal to a second preset voltage, and to limit the discharge current and output a second preset current when the voltage of the DC signal is less than or equal to the first preset voltage; and connected to the energy storage component, the first constant current control component and the light-emitting component, and used for outputting the preset step current corresponding to the light-emitting module to the second constant current control component of the light-emitting component when the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module; Wherein, the conduction voltage of each of the light-emitting modules is greater than or equal to the second preset voltage; When the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module and the voltage of the DC signal increases, the preset step current connected to the light-emitting component increases; When the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module and the voltage of the DC signal decreases, the preset step current connected to the light-emitting component decreases.

2. The linear constant current control circuit according to claim 1, characterized in that: The energy storage component comprises: At least one energy storage component, each of which is connected to each of the light-emitting modules in a one-to-one correspondence, and each of which is connected to the first constant current control component, the second constant current control component and the rectifying component; Each of the energy storage components is used to charge when the voltage of the DC signal is greater than the turn-on voltage of the corresponding light-emitting module, and output the discharge current when the voltage of the DC signal is less than or equal to the first preset voltage.

3. The linear constant current control circuit according to claim 2, characterized in that: Each of the energy storage components comprises: A first diode, a second diode and a first capacitor; The first end of the first capacitor is connected to the first constant current control component and the rectifier component, the anode of the first diode and the cathode of the second diode are connected to the second end of the first capacitor, the cathode of the first diode is connected to the second constant current control component, and the anode of the second diode is connected to the corresponding light-emitting module.

4. The linear constant current control circuit according to claim 1, characterized in that: The first constant current control component comprises: A constant current source connected to the rectifying component and the energy storage component, and configured to be turned on when the voltage of the DC signal is less than or equal to the second preset voltage to output the DC signal or the discharge current; and A current processor connected to the constant current source, the second constant current control component and the light-emitting component, and used for limiting the current of the DC signal or the discharge current.

5. The linear constant current control circuit according to claim 4, characterized in that: The constant current source comprises: an operational amplifier and a first switch tube; The positive input terminal of the operational amplifier is used to connect to the first reference power supply, the output terminal of the operational amplifier is connected to the control terminal of the first switch tube, the first conduction terminal of the first switch tube is connected to the rectifier component and the energy storage component, and the second conduction terminal of the first switch tube and the negative input terminal of the operational amplifier are connected to the current processor.

6. The linear constant current control circuit according to claim 4, characterized in that: The current processor comprises: a first resistor and a second resistor; The first end of the first resistor is connected to the constant current source, the second end of the first resistor and the first end of the second resistor are commonly connected to the second constant current control component, and the second end of the second resistor is connected to the light-emitting component.

7. The linear constant current control circuit according to claim 1, characterized in that: Also includes: A flicker elimination component is connected to the light-emitting component, the first constant current control component and the second constant current control component, and is used to eliminate the flicker of the light-emitting component.

8. A light source system, characterized in that: include: The linear constant current control circuit and the light-emitting component as described in any one of claims 1 to 7, wherein the linear constant current control circuit is connected to the light-emitting component, wherein the light-emitting component includes at least one light-emitting module connected in series.

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