LED protection circuit, control circuit, system and battery protection board

Abstract

The utility model discloses an LED protection circuit, a control circuit, a system and a battery protection board, the LED protection circuit comprises a control circuit, a switch circuit and a current limiting circuit; the first end of the switching circuit is used for connecting an LED circuit; the first end of the current limiting circuit is connected with the second end of the switching circuit, and the second end of the current limiting circuit is grounded; and the control circuit is connected with the control end of the switching circuit and a connection node between the second end of the switching circuit and the current limiting circuit, and is used for controlling the switching circuit to work according to the node current of the connection node. According to the technical scheme, the switching circuit is controlled to work at high frequency, so that the working efficiency is improved, the energy loss is reduced, the switching circuit is controlled to be switched off in time according to the node current fed back by the connection node when the node current is abnormal, and the safety of the LED protection circuit is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of LEDs, and particularly relates to an LED protection circuit, a control circuit, a system and a battery protection board. Background Art

[0002] An LED is a voltage-sensitive electronic device. Excessive current will cause the LED to heat up too quickly, shortening its lifespan or even damaging it. Therefore, in existing LED circuits, a linear voltage regulator is generally used to limit the current in the LED circuit. Although the linear voltage regulator is simple and easy to use, its efficiency is low, resulting in additional energy waste or loss. Summary of the Utility Model

[0003] Embodiments of the utility model provide an LED protection circuit, a control circuit, a system and a battery protection board to solve the problem that the existing LED protection circuit has low efficiency, resulting in additional energy waste or loss.

[0004] An LED protection circuit includes a control circuit, a switching circuit and a current-limiting circuit;

[0005] The first end of the switching circuit is used to connect to an LED circuit;

[0006] The first end of the current-limiting circuit is connected to the second end of the switching circuit, and the second end of the current-limiting circuit is grounded;

[0007] The control circuit is connected to the control end of the switching circuit and the connection node between the second end of the switching circuit and the current-limiting circuit, and is used to control the operation of the switching circuit according to the node current of the connection node.

[0008] Optionally, the switching circuit includes a first switching tube;

[0009] The first end of the first switching tube is used to connect to the LED circuit, and the second end of the first switching tube is connected to the first end of the current-limiting circuit;

[0010] The third end of the first switching tube is connected to the control circuit.

[0011] Optionally, the current-limiting circuit includes a resistor circuit.

[0012] Optionally, the resistor circuit includes a plurality of first resistors, and the plurality of first resistors are connected in series and / or in parallel.

[0013] Optionally, the control circuit includes a comparator and a power supply circuit;

[0014] The non-inverting input terminal of the comparator is used to connect to a signal receiving terminal;

[0015] The inverting input terminal of the comparator is grounded and is connected to the connection node between the second end of the switching circuit and the current limiting circuit through the power feeding circuit;

[0016] The output terminal of the comparator is connected to the switching circuit.

[0017] Optionally, the inverting input terminal of the comparator is grounded through a first capacitor.

[0018] An LED control circuit includes an LED circuit and the above-mentioned LED protection circuit;

[0019] One end of the LED circuit is connected to the LED protection circuit, and the other end is connected to the first power supply terminal.

[0020] Optionally, the LED circuit includes an LED interface;

[0021] The first end of the LED interface is connected to the first end of the switching circuit, the second end of the LED interface is connected to the first power supply terminal, and the LED interface is used to connect an LED device.

[0022] An LED system includes the above-mentioned LED control circuit and an LED device;

[0023] The LED device is connected to the LED circuit.

[0024] A battery protection board includes the above-mentioned LED system.

[0025] In the above-mentioned LED protection circuit, control circuit, system and battery protection board, the LED protection circuit includes a control circuit, a switching circuit and a current limiting circuit; the first end of the switching circuit is used to connect the LED circuit; the first end of the current limiting circuit is connected to the second end of the switching circuit, and the second end of the current limiting circuit is grounded; the control circuit is connected to the control end of the switching circuit and the connection node between the second end of the switching circuit and the current limiting circuit, and is used to control the operation of the switching circuit according to the node current of the connection node. The control circuit controls the switching circuit to work at a high frequency, thereby improving the working efficiency, reducing the energy loss, and according to the node current fed back by the connection node, when the node current is abnormal, timely controls the switching circuit to disconnect, improving the safety of the LED protection circuit. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a schematic circuit diagram of the LED control circuit 1 in an embodiment of the present utility model;

[0028] Figure 2 It is a schematic diagram of the LED system in an embodiment of the present utility model.

[0029] In the figure: 1. LED control circuit; 11. LED protection circuit; 111. Control circuit; 112. Switch circuit; 113. Current limiting circuit; 12. LED circuit; 2. LED device. Detailed implementation manners

[0030] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present utility model.

[0031] It should be understood that the present utility model can be implemented in different forms and should not be construed as limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present utility model to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout the drawings.

[0032] It should be understood that when an element or layer is referred to as being "on", "adjacent to", "connected to" or "coupled to" another element or layer, it can be directly on, adjacent to, connected or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on", "directly adjacent to", "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present utility model, the first element, component, region, layer or part discussed below may be referred to as the second element, component, region, layer or part.

[0033] Spatial relationship terms such as "under", "below", "beneath", "underneath", "above", "over", etc. may be used herein for convenience of description to describe the relationship of one element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relationship terms are also intended to include different orientations of the device in use and operation. For example, if the device in the figures is flipped, then an element or feature described as "under other elements" or "beneath them" or "underneath them" will be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "beneath" can include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are to be interpreted accordingly.

[0034] The purpose of the terms used herein is only to describe specific embodiments and is not intended as a limitation of the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, specify the presence of the features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. As used herein, the term "and / or" includes any and all combinations of the related listed items.

[0035] To fully understand the present invention, detailed structures and steps will be set forth in the following description in order to explain the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention may have other embodiments.

[0036] This embodiment provides an LED protection circuit 11, which is applied to an electronic device. Exemplarily, the electronic device includes a battery and a battery protection board connected to the battery. The LED protection circuit 11 is applied to the battery protection board. The battery protection board LED system, as Figure 2 shown, the LED system includes an LED device 2 and an LED control circuit 1, and the LED control circuit 1 includes the LED protection circuit 11. The LED device 2 includes an LED lamp.

[0037] This embodiment provides an LED protection circuit 11, as Figure 1As shown in the figure, it includes a control circuit 111, a switching circuit 112, and a current limiting circuit 113; the first end of the switching circuit 112 is used to connect to the LED circuit 12; the first end of the current limiting circuit 113 is connected to the second end of the switching circuit 112, and the second end of the current limiting circuit 113 is grounded to GND; the control circuit 111 is connected to the control end of the switching circuit 112 and the connection node between the second end of the switching circuit 112 and the current limiting circuit 113, and is used to control the operation of the switching circuit 112 according to the node current of the connection node.

[0038] As an example, the control circuit 111 is also connected to the main control circuit in the electronic device. After the control circuit 111 receives the first control signal output by the main control circuit, it outputs a second control signal to the switching circuit 112 to control the switching circuit 112 to conduct. The LED circuit 12 and the current limiting circuit 113 form a loop, so that the LED device 2 in the LED circuit 12 can work normally. The current limiting circuit 113 can limit the current in the circuit when the LED circuit 12 is working to prevent the LED device 2 from being damaged by excessive current. At the same time, the control circuit 111 controls the switching circuit 112 to conduct at a high frequency, thereby improving the working efficiency and reducing energy loss. When the control circuit 111 determines that the node current is too large according to the node current of the connection node, it timely controls the switching circuit 112 to disconnect, thereby ensuring the safety of the LED device 2.

[0039] In this embodiment, the LED protection circuit 11 includes a control circuit 111, a switching circuit 112, and a current limiting circuit 113; the first end of the switching circuit 112 is used to connect to the LED circuit 12; the first end of the current limiting circuit 113 is connected to the second end of the switching circuit 112, and the second end of the current limiting circuit 113 is grounded to GND; the control circuit 111 is connected to the control end of the switching circuit 112 and the connection node between the second end of the switching circuit 112 and the current limiting circuit 113, and is used to control the operation of the switching circuit 112 according to the node current of the connection node. The control circuit 111 controls the switching circuit 112 to work at a high frequency, thereby improving the working efficiency and reducing energy loss, and according to the node current fed back by the connection node, when the node current is abnormal, it timely controls the switching circuit 112 to disconnect, improving the safety of the LED protection circuit 11.

[0040] In one embodiment, the switching circuit 112 includes a first switching transistor MD1; the first end of the first switching transistor MD1 is used to connect to the LED circuit 12, the second end of the first switching transistor MD1 is connected to the first end of the current limiting circuit 113; the third end of the first switching transistor MD1 is connected to the control circuit 111.

[0041] As an example, the first switching transistor MD1 includes a field effect transistor or a bipolar transistor.

[0042] As an example, the drain or collector of the first switching transistor MD1 is used to connect to the LED circuit 12, the source or emitter of the first switching transistor MD1 is connected to the first end of the current limiting circuit 113, and the gate or base of the first switching transistor MD1 is connected to the control circuit 111.

[0043] In this embodiment, the control circuit 111 controls the first switching transistor MD1 to operate at a high frequency to reduce energy loss.

[0044] In one embodiment, the current limiting circuit 113 includes a resistor circuit. In this embodiment, the resistor circuit limits the magnitude of the current in the LED protection circuit 11, and the circuit is simple, reducing costs.

[0045] In one embodiment, the resistor circuit includes a plurality of first resistors R1, and the plurality of first resistors R1 are connected in series and / or in parallel. In this embodiment, the resistor circuit includes a plurality of first resistors R1, and the plurality of first resistors R1 are connected in series and / or in parallel, so as to flexibly configure the resistor circuit according to actual needs, thereby flexibly adjusting the magnitude of the current in the LED protection circuit 11. Exemplarily, the plurality of first resistors R1 include, for example, Figure 1 the resistors R4, R5, and R6 connected in parallel as shown.

[0046] In one embodiment, the control circuit 111 includes a comparator U1 and a feeding circuit; the non-inverting input terminal +In of the comparator U1 is used to connect to the signal receiving terminal; the inverting input terminal -In of the comparator U1 is grounded to GND and is connected to the connection node between the second end of the switching circuit 112 and the current limiting circuit 113 through the feeding circuit; the output terminal Out of the comparator U1 is connected to the switching circuit 112.

[0047] As an example, the feeding circuit includes a feeding resistor R7.

[0048] As an example, the signal receiving terminal is connected to the main control circuit in the electronic device for receiving the first control signal output by the main control circuit.

[0049] As an example, the control circuit 111 further includes a first voltage dividing circuit, and the non-inverting input terminal +In of the comparator U1 is connected to the signal receiving terminal through the first voltage dividing circuit. The first end of the first voltage dividing circuit is connected to the signal receiving terminal, the second end of the first voltage dividing circuit is grounded to GND, and the third end of the first voltage dividing circuit is connected to the non-inverting input terminal +In of the comparator U1. Exemplarily, the first voltage dividing circuit includes a first resistor R1 and a second resistor R2 connected in series between the first end and the second end of the first voltage dividing circuit, and the connection node between the first resistor R1 and the second resistor R2 is the third end of the first voltage dividing circuit.

[0050] As an example, the output terminal Out of the comparator U1 is connected to the switching circuit 112 through a first driving resistor R3.

[0051] As an example, the positive terminal +Vs of the comparator U1 is connected to the 3.3V supply voltage, and the negative terminal -Vs of the comparator U1 is grounded to GND.

[0052] In this embodiment, when the signal receiving end receives the first control signal, through the voltage division function of the first voltage division circuit, the first control signal is input to the non-inverting input terminal +In of the comparator U1. The inverting input terminal -In of the comparator U1 is grounded to GND, and is connected to the connection node between the second terminal of the switch circuit 112 and the current limiting circuit 113 through the feeding circuit. Thus, the comparator U1 serves as the voltage comparator U1. When the voltage at the non-inverting input terminal +In of the comparator U1 is greater than zero, the voltage at the output terminal Out of the comparator U1 is limited to about 3.3V. Thus, the output terminal Out of the comparator U1 outputs the second control signal to drive the switch circuit 112 to conduct, and according to the node current of the connection node, when the node current is abnormal, the switch circuit 112 is controlled to turn off, preventing excessive current from damaging the LED device 2, thereby improving the safety of the LED protection circuit 11.

[0053] In one embodiment, the inverting input terminal -In of the comparator U1 is grounded to GND through the first capacitor C1. In this embodiment, the first capacitor C1 is used to achieve AC filtering and decoupling functions, prevent interference signals, and improve the anti-interference ability of the comparator U1.

[0054] This embodiment provides an LED control circuit 1, including an LED circuit 12 and the above-mentioned LED protection circuit 11; one end of the LED circuit 12 is connected to the LED protection circuit 11, and the other end is connected to the first power supply terminal VCC. As an example, the first power supply terminal VCC is used to provide a working power supply for the LED circuit 12, and the first power supply terminal VCC is used to connect to an energy storage device or a power grid.

[0055] In one embodiment, the LED circuit 12 includes an LED interface P1; the first end of the LED interface P1 is connected to the first end of the switch circuit 112, the second end of the LED interface P1 is connected to the first power supply terminal VCC, and the LED interface P1 is used to connect the LED device 2. In this embodiment, by connecting the LED device 2 through the LED interface P1, it is convenient to replace the LED device 2 when the LED device 2 is damaged. As Figure 1 shown, the L- and L+ of the LED interface P1 are used to connect the LED device 2.

[0056] This embodiment provides an LED system, including the above-mentioned LED control circuit 1 and the LED device 2; the LED device 2 is connected to the LED circuit 12.

[0057] This embodiment provides a battery protection board, including the above-mentioned LED system. Exemplarily, this battery protection board is applied in an electronic device. The electronic device includes a battery. The battery protection board is connected to the battery. The LED circuit 12 is connected to the battery through the first power supply terminal VCC.

[0058] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; 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 recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. An LED protection circuit, characterized in that: Including control circuit, switch circuit and current limiting circuit; The first end of the switch circuit is used to connect to the LED circuit; The first end of the current limiting circuit is connected to the second end of the switch circuit, and the second end of the current limiting circuit is grounded; The control circuit is connected to the control end of the switch circuit and the connection node between the second end of the switch circuit and the current limiting circuit, and is used to control the operation of the switch circuit according to the node current of the connection node.

2. The LED protection circuit according to claim 1, characterized in that: The switch circuit comprises a first switch tube; The first end of the first switch tube is used to connect to the LED circuit, and the second end of the first switch tube is connected to the first end of the current limiting circuit; The third end of the first switch tube is connected to the control circuit.

3. The LED protection circuit according to claim 1, characterized in that: The current limiting circuit includes a resistance circuit.

4. The LED protection circuit according to claim 3, characterized in that: The resistance circuit includes a plurality of first resistors, and the plurality of first resistors are connected in series and / or in parallel.

5. The LED protection circuit according to claim 1, characterized in that: The control circuit includes a comparator and a feeding circuit; The non-inverting input terminal of the comparator is used to connect to the signal receiving terminal; The inverting input terminal of the comparator is grounded and connected to a connection node between the second terminal of the switch circuit and the current limiting circuit through the feeding circuit; The output terminal of the comparator is connected to the switch circuit.

6. The LED protection circuit according to claim 5, characterized in that: The inverting input terminal of the comparator is grounded through a first capacitor.

7. An LED control circuit, characterized in that: comprising an LED circuit and an LED protection circuit as claimed in any one of claims 1 to 6; One end of the LED circuit is connected to the LED protection circuit, and the other end is connected to the first power supply end.

8. The LED control circuit according to claim 7, characterized in that: The LED circuit includes an LED interface; The first end of the LED interface is connected to the first end of the switch circuit, the second end of the LED interface is connected to the first power supply end, and the LED interface is used to connect an LED device.

9. An LED system, characterized in that: Comprising the LED control circuit and LED device according to any one of claims 7 to 8; The LED device is connected to the LED circuit.

10. A battery protection board, characterized in that: Comprising the LED system as claimed in claim 9.

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