Light-emitting control circuit and monitoring device

Abstract

The present invention discloses a light-emitting control circuit and a monitoring device. The light-emitting control circuit includes: at least two light-emitting branches; at least two switching elements respectively arranged on the at least two light-emitting branches to select at least one light-emitting branch to work; a constant-current chip including an output end and a feedback end, wherein the output end is respectively connected to the at least two light-emitting branches to provide a driving signal for the selected light-emitting branch, and the feedback end is respectively connected to the at least two light-emitting branches to collect the feedback signal of the selected light-emitting branch, so that the constant-current chip adjusts the driving signal, thereby making the current flowing through the selected light-emitting branch a preset constant current. By the above method, the present invention can simplify the circuit structure to reduce the occupied resources and is beneficial to reducing the manufacturing cost.

Description

Technical Field

[0001] The present invention relates to the field of electric lighting, and particularly to a light-emitting control circuit. Background Art

[0002] At present, LEDs are widely used as light sources in various fields, and various LED driving circuits have emerged. Moreover, at present, most multi-channel LED drives basically adopt constant-current driving, which can be divided into boost-type constant-current driving and buck-type constant-current driving according to different input voltages; in the field of monitoring equipment, cameras often adopt integrated zoom camera modules, such as high-speed dome cameras and other monitoring equipment. In order to achieve supplementary lighting in a night environment, multiple groups of infrared lamps are often used in cooperation with the angle of the camera module to achieve infrared supplementary lighting at different angles of the camera module.

[0003] In existing high-speed dome cameras or other similar monitoring equipment, generally two-way infrared lamps or one-way infrared lamp and one-way white light lamp need to be controlled in actual applications. In the existing drive circuit design, the hardware design often requires two or more constant-current drive chips to drive a multi-channel light-emitting circuit. Due to the high cost of the chips, the manufacturing cost of the equipment is also high, and the hardware design is complex. Excessive circuit components cause the volume of the PCB (Printed Circuit Board) to increase, wasting PCB resources. Summary of the Invention

[0004] In view of this, the main technical problem to be solved by the present invention is to provide a light-emitting control circuit, which can simplify the circuit structure to reduce the occupied resources and is beneficial to reducing the manufacturing cost.

[0005] To solve the above technical problem, a technical solution adopted by the present invention is: to provide a light-emitting control circuit. The light-emitting control circuit includes at least two light-emitting branches; at least two switching elements respectively arranged on at least two light-emitting branches to select at least one light-emitting branch to work; a constant-current chip including an output end and a feedback end. The output end is respectively connected to at least two light-emitting branches to provide a driving signal for the selected light-emitting branch, and the feedback end is respectively connected to at least two light-emitting branches to collect the feedback signal of the selected light-emitting branch, so that the constant-current chip adjusts the driving signal, thereby making the current flowing through the selected light-emitting branch a preset constant current.

[0006] In an embodiment of the present invention, at least two light-emitting branches include at least one first light-emitting branch and at least one second light-emitting branch, wherein a preset first constant current corresponding to the first light-emitting branch is different from a preset second constant current corresponding to the second light-emitting branch; when the selected light-emitting branch is the first light-emitting branch, the feedback terminal of the constant current chip collects the feedback signal of the selected first light-emitting branch and adjusts the drive signal output by the output terminal so that the current flowing through the selected first light-emitting branch is the preset first constant current; when the selected light-emitting branch is the second light-emitting branch, the feedback terminal of the constant current chip collects the feedback signal of the selected second light-emitting branch and adjusts the drive signal output by the output terminal so that the current flowing through the selected second light-emitting branch is the preset second constant current.

[0007] In an embodiment of the present invention, the first light-emitting branch is an infrared light-emitting branch, and the second light-emitting branch is a white light-emitting branch.

[0008] In an embodiment of the present invention, the light-emitting control circuit further includes a sampling circuit, including a plurality of sampling modules, wherein one corresponding sampling module is arranged on each light-emitting branch so that each light-emitting branch generates a feedback signal through the sampling module.

[0009] In an embodiment of the present invention, the sampling module is a sampling resistor, and each light-emitting branch is grounded through the corresponding sampling resistor.

[0010] In an embodiment of the present invention, the light-emitting control circuit further includes a unidirectional conduction circuit, including a plurality of unidirectional conduction components, wherein one corresponding unidirectional conduction component is arranged between each light-emitting branch and the feedback terminal of the constant current chip so that the feedback terminal unidirectionally receives the feedback signal of each light-emitting branch and isolates the influence between at least two light-emitting branches.

[0011] In an embodiment of the present invention, the unidirectional conduction component is a diode.

[0012] In an embodiment of the present invention, the constant current chip further includes an input terminal (VIN) and a drain terminal (LX), wherein the input terminal is used to receive an input voltage (VDD_IR), and a ballast inductor is arranged between the input terminal and the drain terminal.

[0013] In an embodiment of the present invention, a freewheeling diode is arranged between the drain terminal and the output terminal of the constant current chip.

[0014] To solve the above technical problems, another technical solution adopted by the present invention is: to provide a monitoring device. The monitoring device includes the light-emitting control circuit described in the above embodiment.

[0015] The beneficial effects of the present invention are as follows: Different from the prior art, the present invention provides a light-emitting control circuit and a monitoring device. The output terminals of a constant-current chip are respectively connected to at least two light-emitting branches to provide drive signals for the selected light-emitting branches, and the feedback terminals are respectively connected to at least two light-emitting branches to collect feedback signals of the selected light-emitting branches, so that the constant-current chip adjusts the drive signals, thereby making the current flowing through the selected light-emitting branches be a preset constant current. That is to say, by controlling at least two light-emitting branches with a constant-current chip, the current flowing through the selected light-emitting branches is a preset constant current, so that a constant-current chip can control multiple light-emitting branches, thereby simplifying the circuit structure, reducing the occupied resources, and being beneficial to reducing the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention. In addition, these drawings and the text description are not intended to limit the scope of the inventive concept in any way, but to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments.

[0017] Figure 1 is a schematic structural diagram of an embodiment of the light-emitting control circuit of the present invention;

[0018] Figure 2 is a schematic structural diagram of another embodiment of the light-emitting control circuit of the present invention;

[0019] Figure 3 is a schematic structural diagram of an embodiment of the monitoring device of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0021] To solve the technical problem of complex drive circuits for on-road lighting circuits in the prior art, an embodiment of the present invention provides a lighting control circuit. The lighting control circuit includes at least two lighting branches; at least two switching elements respectively arranged on at least two lighting branches to select at least one lighting branch to operate; a constant current chip including an output terminal and a feedback terminal. Wherein, the output terminal is respectively connected to at least two lighting branches to provide a drive signal for the selected lighting branch, and the feedback terminal is respectively connected to at least two lighting branches to collect the feedback signal of the selected lighting branch, so that the constant current chip adjusts the drive signal, thereby making the current flowing through the selected lighting branch a preset constant current.

[0022] In this way, the lighting control circuit of this embodiment can drive at least two lighting branches, realizing that one constant current chip drives multiple lighting branches to operate, simplifying the circuit structure, thus reducing the occupied resources and being beneficial to reducing the manufacturing cost.

[0023] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of an embodiment of the lighting control circuit of the present invention.

[0024] In one embodiment, the lighting control circuit includes at least two lighting branches 1, and the lighting branches 1 are used for lighting or for infrared light supplementation. Optionally, the at least two lighting branches 1 can be infrared lamps and / or white lamps, etc.

[0025] The lighting control circuit further includes at least two switching elements 2. The at least two switching elements 2 are respectively arranged on at least two lighting branches 1 to select at least one lighting branch 1 to operate. That is, by turning on and off the switching element 2, at least one of the lighting branches 1 can be selected to operate.

[0026] The lighting control circuit further includes a constant current chip 3, including an output terminal 31 and a feedback terminal 32. Wherein, the output terminal 31 is respectively connected to at least two lighting branches 1, and the constant current chip 3 provides a drive signal for the selected lighting branch 1 through the output terminal 31, and the drive signal can drive the selected lighting branch 1 to operate; the feedback terminal 32 is respectively connected to at least two lighting branches 1 to collect the feedback signal of the selected lighting branch 1, so that the constant current chip 3 adjusts the drive signal, thereby making the current flowing through the selected lighting branch 1 a preset constant current. Among them, the drive signal output by the output terminal 31 of the constant current chip 3 can be a corresponding output voltage or current, etc., and the feedback signal collected by the feedback terminal 32 can be an electrical signal that the constant current chip 3 can recognize, etc.

[0027] It is easy to understand that the constant current chip 3 provides a driving signal for the selected light-emitting branch 1 through the output terminal 31. After the light-emitting branch 1 is driven, a feedback signal is generated. The feedback terminal 32 of the constant current chip 3 can collect the corresponding feedback signal and feed it back to the constant current chip 3. Thus, the constant current chip 3 adjusts the driving signal output via the output terminal 31 according to the feedback signal.

[0028] Among them, the number of the light-emitting branches 1 is at least two, which means that the light-emitting control circuit of this embodiment can control at least two light-emitting branches 1. Compared with the prior art where the constant current chip 3 can only control one light-emitting branch 1 connected thereto, the light-emitting control circuit of this embodiment can control multiple light-emitting branches 1 through a simple circuit structure, thereby being able to simplify the circuit structure to reduce the occupied resources and being beneficial to reducing the manufacturing cost.

[0029] Figure 1 It shows the situation where the light-emitting control circuit includes two light-emitting branches 1, each light-emitting branch 1 is connected to the output terminal 31 of the constant current chip 3, and each light-emitting branch 1 is respectively connected to a switching element 2. The above is only for the need of discussion and does not limit the circuit architecture of the light-emitting control circuit of this embodiment.

[0030] Therefore, please refer to Figure 2 , Figure 2 the structural schematic diagram of another embodiment of the light-emitting control circuit of the present invention.

[0031] In one embodiment, the light-emitting control circuit includes at least two light-emitting branches 1, at least two switching elements 2, and a constant current chip 3. And the light-emitting branches 1, switching elements 2, and constant current chip 3 included in this embodiment are respectively the same as the light-emitting branches 1, switching elements 2, and constant current chip 3 in the above-mentioned embodiment of the light-emitting control circuit of the present invention, and will not be elaborated here.

[0032] Generally speaking, if the preset constant current of each light-emitting branch 1 is the same, then the constant current chip 3 only needs to provide the same output voltage to make the current flowing through the corresponding light-emitting branch 1 be the preset constant current. To apply the light-emitting control circuit of this embodiment to more application scenarios, due to reasons such as different uses or specifications, there may be differences between at least two light-emitting branches 1 connected to the same constant current chip 3. Therefore, when driving different selected light-emitting branches 1 to work through the constant current chip 3, the same output signal cannot be output to the light-emitting branches 1, such as outputting the same current to the light-emitting branches 1, which not only cannot make the current flowing through the selected light-emitting branch 1 be the preset constant current, but may even cause damage to the light-emitting elements of the light-emitting branch 1.

[0033] Therefore, in one embodiment, the above at least two light-emitting branches 1 include at least one first light-emitting branch 11 and at least one second light-emitting branch 12, wherein the preset first constant current corresponding to the first light-emitting branch 11 is different from the preset second constant current corresponding to the second light-emitting branch 12. That is, the first light-emitting branch 11 is different from the second light-emitting branch 12, and the input current required when the first light-emitting branch 11 works is also different from the input current required for the second light-emitting branch 12 to work.

[0034] Figure 2 The case where the light-emitting control circuit includes one first light-emitting branch 11 and one second light-emitting branch 12 is shown. The circuit structure shown in the figure is only for the need of discussion and does not limit the circuit architecture of the light-emitting control circuit in this embodiment. And, based on Figure 2 the circuit shown and the description of the embodiment, those skilled in the art can think of the specific circuit architecture of the light-emitting control circuit when the number of light-emitting branches 1 is more than two.

[0035] Specifically, when the selected light-emitting branch 1 is the first light-emitting branch 11, the feedback terminal 32 of the constant current chip 3 collects the feedback signal of the selected first light-emitting branch 11, and processes and analyzes the collected feedback signal, so as to adjust the driving signal output by the output terminal 31 according to the feedback signal, so that the current flowing through the selected first light-emitting branch 11 is the preset first constant current, and then drive the first light-emitting branch 11 to work normally. When the selected light-emitting branch 1 is the second light-emitting branch 12, the feedback terminal 32 of the constant current chip 3 collects the feedback signal of the selected second light-emitting branch 12, and processes and analyzes the collected feedback signal, so as to adjust the driving signal output by the output terminal 31 according to the feedback signal, so that the current flowing through the selected second light-emitting branch 12 is the preset second constant current, and then drive the second light-emitting branch 12 to work normally. Among them, the first constant current is different from the second constant current, so that the constant current chip 3 can output corresponding driving signals according to the working conditions of different light-emitting branches 1, reducing the number of applications of the constant current chip 3. Furthermore, the circuit structure can be simplified, the occupied resources can be reduced, and it is beneficial to reduce the manufacturing cost.

[0036] Optionally, the first light-emitting branch 11 can be an infrared light-emitting branch, etc., and the second light-emitting branch 12 can be a white light-emitting branch, etc. Taking the application scenario as a monitoring device as an example, the infrared light-emitting branch can perform infrared fill light on the monitoring environment when the lighting conditions are poor, and the white light-emitting branch can assist in monitoring lighting when the lighting conditions are good, so as to achieve energy conservation and environmental protection while meeting the monitoring needs.

[0037] Please continue to refer to Figure 2。In one embodiment, to facilitate the feedback terminal 32 of the constant current chip 3 to collect the feedback signal of the selected light-emitting branch 1, the light-emitting control circuit further includes a sampling circuit 4, and the sampling circuit 4 includes a plurality of sampling modules 41.

[0038] Specifically, one corresponding sampling module 41 is provided on each light-emitting branch 1, so that each light-emitting branch 1 generates a feedback signal through the sampling module 41. That is to say, each light-emitting branch 1 is connected to a sampling module 41, and the sampling module 41 can collect the feedback signal of the light-emitting branch 1, so that the feedback terminal 32 of the constant current chip 3 can obtain the feedback signal and use the feedback signal to adjust the driving signal output by the output terminal 31.

[0039] Optionally, the sampling module 41 can be, for example, Figure 2 the sampling resistor R shown in, etc. Each light-emitting branch 1 is connected to the sampling resistor R and grounded (or connected to the ground voltage) through the corresponding sampling resistor R. The sampling resistor R can be connected in parallel to the corresponding light-emitting branch 1 to sample the voltage of the light-emitting branch 1 (not shown in the figure), or can be connected in series to the corresponding light-emitting branch 1 to sample the current flowing through the light-emitting branch 1 (as shown in Figure 2 ), so that the constant current chip 3 can obtain the current situation of the working light-emitting branch 1.

[0040] Please continue to refer to Figure 2 。In one embodiment, the light-emitting control circuit further includes a one-way conduction circuit 5, which includes a plurality of one-way conduction components 51.

[0041] Specifically, one corresponding one-way conduction component 51 is provided between each light-emitting branch 1 and the feedback terminal 32 of the constant current chip 3, so that the feedback terminal 32 unidirectionally receives the feedback signal of each light-emitting branch 1, thereby isolating the influence between at least two light-emitting branches 1, avoiding the current flowing from the selected working light-emitting branch 1 to other light-emitting branches 1, affecting the feedback signal collected by the feedback terminal 32 of the constant current chip 3 or causing the circuit working state to be disordered. Furthermore, through the one-way conduction circuit 5, the reliability of the light-emitting control circuit in this embodiment can be ensured.

[0042] Optionally, the one-way conduction component 51 can be, for example, Figure 2 the diode D1 shown in, etc., or other circuits or circuit components that can achieve the one-way conduction function, which are not limited here. The cathode of the diode D1 is connected to the feedback terminal 32 of the constant current chip 3, and the anode of the diode D1 is connected between the switching element 2 and the sampling module 41.

[0043] Furthermore, the diode D1 can be selected as a Schottky diode, etc. The Schottky diode has a small voltage drop and low cost, which is beneficial to further reducing the manufacturing cost.

[0044] Please continue to refer toFigure 2 。In one embodiment, the switching element 2 can be an NMOS (N-Metal-Oxide-Semiconductor) transistor Q as shown in Figure 2 . Both ends of the switching element 2 are respectively connected to the light-emitting branch 1 and the sampling module 41. Each switching element 2 is also respectively connected to other external modules, and specifically selects the light-emitting branch 1 to work through other external modules.

[0045] Please continue to refer to Figure 2 . In one embodiment, the constant-current chip 3 further includes an input terminal 33 (such as the VIN pin shown in Figure 2 ) and a drain terminal 34 (such as the LX pin shown in Figure 2 ). Among them, the input terminal 33 is used to receive an input voltage (such as the VDD_IR shown in Figure 2 ).

[0046] Furthermore, a ballast inductor L is provided between the input terminal 33 and the drain terminal 34. The ballast inductor L can play a role in current limiting and can reduce the noise generated when the light-emitting control circuit of this embodiment works.

[0047] Still further, a freewheeling diode D2 is provided between the drain terminal 34 of the constant-current chip 3 and the output terminal 31. The anode of the freewheeling diode D2 is connected to the drain terminal 34 of the constant-current chip 3 and the ballast inductor L, and the cathode of the freewheeling diode D2 is connected to the output terminal 31 of the constant-current chip 3 and the light-emitting branch 1. The freewheeling diode D2 can prevent voltage and current mutations and is used to provide a continuous current for the light-emitting branch 1 to smooth the current input to the light-emitting branch 1.

[0048] Please continue to refer to Figure 2 . In one embodiment, the constant-current chip 3 further includes an enable terminal 35 (such as the CE shown in Figure 2 ), and the enable terminal 35 can be connected to a PWM (Pulse Width Modulation) circuit 6.

[0049] Specifically, when the light-emitting control circuit works, the input terminal 33 and the enable terminal 35 of the constant-current chip 3 are powered on to work. The current flows into the constant-current chip 3 through the drain terminal 34. The feedback terminal 32 collects the feedback signal (such as a current sampling signal) of the selected light-emitting branch 1 and sends it to the constant-current chip 3. The constant-current chip 3 compares and analyzes the feedback signal and adjusts the on / off time of the drain terminal 34 to achieve the purpose of constant current.

[0050] Furthermore, by changing the duty cycle of the PWM circuit 6, the magnitude of the preset constant current output to the light-emitting branch 1 can be changed, so that the brightness of the light-emitting branch 1 can be adjusted, and further the function of the light-emitting control circuit can be increased.

[0051] Further, the constant current chip 3 further includes a ground terminal 36 (such as GND shown in Figure 2 ), and the ground terminal 36 is used for grounding (or connecting to ground voltage).

[0052] Please continue to refer to Figure 2 . In an embodiment, the light-emitting control circuit further includes a bypass capacitor C1 and a filter capacitor C2. The bypass capacitor C1 and the filter capacitor C2 play the roles of filtering and energy storage. Among them, the bypass capacitor C1 can filter out power supply noise, and the filter capacitor C2 can improve the stability of the circuit and affect the output voltage ripple.

[0053] Please refer to Figure 3 , Figure 3 which is a schematic structural diagram of an embodiment of the monitoring device of the present invention.

[0054] In an embodiment, the monitoring device 7 includes a light-emitting control circuit 71. It should be noted that the working principle of the light-emitting control circuit 71 in this embodiment is the same as that of the light-emitting control circuit 71 described in the above embodiment, and will not be elaborated here.

[0055] Further, the monitoring device 7 of the present invention further includes a control module 72, and the control module 72 is connected to the light-emitting control circuit 71. The control module 72 is used to control the monitoring device 7 to perform monitoring, and is respectively connected to the switching elements of each light-emitting control circuit 71, and further controls the on and off of the switching elements to select the specific working light-emitting branch. The control module 72, that is, the main board of the monitoring device 7, is used to coordinate the cooperative work of the various components of the monitoring device 7.

[0056] In summary, for the light-emitting control circuit and the monitoring device provided by the present invention, the output terminals of the constant current chip are respectively connected to at least two light-emitting branches to provide drive signals for the selected light-emitting branches, and the feedback terminals are respectively connected to at least two light-emitting branches to collect the feedback signals of the selected light-emitting branches, so that the constant current chip adjusts the drive signals, thereby making the current flowing through the selected light-emitting branches be a preset constant current. That is to say, by controlling at least two light-emitting branches through the constant current chip, the current flowing through the selected light-emitting branches is a preset constant current, so that a constant current chip can control multiple light-emitting branches, thereby simplifying the circuit structure to reduce the occupied resources and being beneficial to reducing the manufacturing cost.

[0057] In addition, in the present invention, unless otherwise clearly defined and limited, terms such as "connected", "coupled", "stacked" and the like shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A light emission control circuit, characterized in that, Comprising: At least two light-emitting branches; At least two switching elements, respectively arranged on the at least two light-emitting branches to select at least one of the light-emitting branches to operate; A constant-current chip, including an output terminal and a feedback terminal. Wherein, the output terminal is respectively connected to the at least two light-emitting branches to provide a driving signal for the selected light-emitting branch, and the feedback terminal is respectively connected to the at least two light-emitting branches to collect the feedback signal of the selected light-emitting branch, so that the constant-current chip adjusts the driving signal, thereby making the current flowing through the selected light-emitting branch a preset constant current; The at least two light-emitting branches include at least one first light-emitting branch and at least one second light-emitting branch. Wherein, the preset first constant current corresponding to the first light-emitting branch is different from the preset second constant current corresponding to the second light-emitting branch.

2. The light-emitting control circuit according to claim 1, wherein: When the selected light-emitting branch is the first light-emitting branch, the feedback terminal of the constant-current chip collects the feedback signal of the selected first light-emitting branch, and adjusts the driving signal output by the output terminal, so that the current flowing through the selected first light-emitting branch is the preset first constant current; When the selected light-emitting branch is the second light-emitting branch, the feedback terminal of the constant-current chip collects the feedback signal of the selected second light-emitting branch, and adjusts the driving signal output by the output terminal, so that the current flowing through the selected second light-emitting branch is the preset second constant current.

3. The light-emitting control circuit according to claim 2, wherein The first light-emitting branch is an infrared light-emitting branch, and the second light-emitting branch is a white light-emitting branch.

4. The light-emitting control circuit according to claim 1, wherein Further comprising: A sampling circuit, including a plurality of sampling modules. Wherein, one corresponding sampling module is arranged on each light-emitting branch, so that each light-emitting branch generates the feedback signal through the sampling module.

5. The light-emitting control circuit according to claim 4, characterized in that, The sampling module is a sampling resistor, and each light-emitting branch is respectively grounded through the corresponding sampling resistor.

6. The light-emitting control circuit according to claim 1, wherein Further comprising: A unidirectional conduction circuit, including a plurality of unidirectional conduction components. Wherein, one corresponding unidirectional conduction component is arranged between each light-emitting branch and the feedback terminal of the constant-current chip, so that the feedback terminal unidirectionally receives the feedback signal of each light-emitting branch, isolating the influence between the at least two light-emitting branches.

7. The light-emitting control circuit according to claim 6, wherein The unidirectional conduction component is a diode.

8. The light emission control circuit according to claim 1, wherein The constant-current chip further includes an input terminal and a drain terminal. Wherein, the input terminal is used to receive an input voltage, and a ballast inductor is arranged between the input terminal and the drain terminal.

9. The light emission control circuit according to claim 8, wherein A freewheeling diode is arranged between the drain terminal and the output terminal of the constant-current chip.

10. A monitoring device, characterized in that, Comprising the light-emitting control circuit according to any one of claims 1-9.

Images