Differential mode surge protection circuit, filter and photovoltaic energy controller
By introducing differential mode protection and common mode protection modules into the RS485 module, the fuse discharge problem is solved, the circuit is protected, the chip area is reduced, and stable communication of the RS485 module is achieved.
Patent Information
- Application Number
- CN202520312322.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-25
- Publication Date
- 2026-02-06
- Estimated Expiration
- 2035-02-25
AI Technical Summary
In existing technologies, under lightning surge conditions, the relative position of the fuses in an RS485 circuit module is reduced, leading to discharge behavior and damaging the circuit.
The RS485 module introduces first and second differential mode protection modules. The first differential mode protection module is set at the front end of fuses FU1 and FU2 to discharge the energy of external differential mode surge voltage, and the second differential mode protection module performs secondary discharge. Combined with the common mode protection module, signal filtering is performed to avoid discharge behavior.
It effectively prevents fuse discharge, protects the normal communication of the RS485 module, reduces the chip area, and reduces the impact of common-mode interference.
Smart Images
Figure CN223884948U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of electronic circuits, in particular to a differential mode surge protection circuit, a filter and a photovoltaic energy controller. BACKGROUND
[0002] The RS485 circuit module faces the problem of lightning surge in source system application. In the prior art, a protection circuit is usually added in the RS485 circuit module to solve the problem of lightning surge.
[0003] However, in the prior art, in order to reduce the chip area, the relative positions of the two fuses in the protection circuit are usually reduced. However, when the relative positions are too small, the surge voltage will cause the discharge behavior between the protection fuses. The long-time discharge behavior will cause the device to be damaged, thereby damaging the entire circuit. Utility model content
[0004] Therefore, it is necessary to provide a differential mode surge protection circuit, a filter and a photovoltaic energy controller which can prevent the discharge behavior of the fuse in the differential mode surge protection.
[0005] In a first aspect, a differential mode surge protection circuit is provided. The circuit is used in an RS485 module, and the circuit comprises:
[0006] A fuse FU1 is connected between a first differential input terminal of the RS485 module and an access terminal through a first wire.
[0007] A fuse FU2 is connected between a second differential input terminal of the RS485 module and the access terminal through a second wire. The access terminal is used to access an external differential mode surge voltage.
[0008] A first differential mode protection module is connected between the fuse FU1 and the access terminal at a first end, and is connected between the fuse FU2 and the access terminal at a second end. The first differential mode protection module is used to discharge the external differential mode surge voltage, and outputs a first differential mode voltage through the fuse FU1 and the fuse FU2.
[0009] A second differential mode protection module is connected between the first differential input terminal of the RS485 module and the fuse FU1 at a first end, is connected between the second differential input terminal of the RS485 module and the fuse FU2 at a second end, and is connected to a common ground at a third end. The second differential mode protection module is used to discharge the first differential mode voltage, and outputs a second differential mode voltage to the RS485 module.
[0010] In one of the embodiments, the first differential mode protection module comprises a surge suppressor TSS3,
[0011] A first end of the surge suppressor TSS3 is connected between the fuse FU1 and the access terminal; a second end of the surge suppressor TSS3 is connected between the fuse FU2 and the access terminal.
[0012] In one of the embodiments, the second differential mode protection module comprises a surge suppressor TSS1, a surge suppressor TSS2,
[0013] A first end of the surge suppressor TSS1 is connected to the common ground, and a second end of the surge suppressor TSS1 is connected between the first differential input of the RS485 module and the fuse FU1;
[0014] A first end of the surge suppressor TSS2 is connected to the common ground, and a second end of the surge suppressor TSS2 is connected between the second differential input of the RS485 module and the fuse FU2.
[0015] In one of the embodiments, the circuit further comprises a common mode protection module, a first end of the common mode protection module is connected between the fuse FU1 and the access terminal, a second end of the common mode protection module is connected between the fuse FU2 and the access terminal, and a third end of the common mode protection module is connected to the common ground,
[0016] The common mode protection module is configured to perform common mode signal filtering on the external differential mode surge voltage, and input the filtered external differential mode surge voltage to the first differential mode protection module.
[0017] In one of the embodiments, the common mode protection module comprises a capacitor C1 and a capacitor C2,
[0018] One end of the capacitor C1 is connected between the fuse FU1 and the access terminal, and the other end of the capacitor C1 is connected to the common ground;
[0019] One end of the capacitor C2 is connected between the fuse FU2 and the access terminal, and the other end of the capacitor C2 is connected to the common ground.
[0020] In one of the embodiments, a distance between the fuse FU1 and the fuse FU2 is less than or equal to 0.6 millimeters.
[0021] In one of the embodiments, lengths of the first wire and the second wire are equal.
[0022] In one of the embodiments, a ground pin of the access terminal is connected to the common ground.
[0023] In a second aspect, a filter is provided, which comprises the differential mode surge protection circuit according to the first aspect.
[0024] In a third aspect, a photovoltaic energy controller is provided, which comprises an RS485 module and the differential mode surge protection circuit according to the first aspect, and the RS485 module is connected with the differential mode surge protection circuit through the first wire and the second wire.
[0025] The differential mode surge protection circuit, the filter and the photovoltaic energy controller have the following advantages. The first differential mode protection module is arranged at the front end of the two fuses, and the first differential mode protection module discharges the energy of the external differential mode surge voltage entering the circuit and outputs the first differential mode voltage to the two fuses, so that the discharge behavior of the external differential mode surge voltage is avoided when the two fuses are very close. The second differential mode protection module discharges the first differential mode voltage after energy discharge for the second time, so that the final voltage does not have a negative impact on the normal communication of the RS485 module and protects the circuit. BRIEF DESCRIPTION OF DRAWINGS
[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.
[0027] Figure 1 The structural block diagram of the differential mode surge protection circuit of an embodiment;
[0028] Figure 2 The structural block diagram of the differential mode surge protection circuit of another embodiment;
[0029] Figure 3 The structural block diagram of the differential mode surge protection circuit of still another embodiment;
[0030] Figure 4 The structural block diagram of the differential mode surge protection circuit of still another embodiment;
[0031] Figure 5 The circuit diagram of the differential mode surge protection circuit of a preferred embodiment. DETAILED DESCRIPTION
[0032] For the purpose of clarity, the present application will be described in greater detail below with reference to the accompanying drawings. The embodiments of the present application are shown in the drawings. However, the present application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art.
[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
[0034] It should be understood that the terms "first", "second" and so on used herein can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of the present application, a first resistor can be referred to as a second resistor, and similarly, a second resistor can be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.
[0035] It should be understood that "connection" in the following embodiments means that the circuits, modules, units, etc. connected to each other have transmission of electrical signals or data.
[0036] It should be understood that "at least one" means one or more, and "multiple" means two or more. "At least part of an element" means part or all of the element.
[0037] As used herein, the singular forms "a", "an" and "the" can include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "comprise / comprising" or "have / having" specifies the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but does not exclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in the specification includes any and all combinations of the related listed items.
[0038] As Figure 1 As shown in FIG. 1, a differential mode surge protection circuit according to an embodiment includes a fuse FU1, a fuse FU2, a first differential mode protection module 100, a second differential mode protection module 200, and an access terminal 300.
[0039] Fuse FU1 connects the first differential input end A of the RS485 module with the access terminal 300 through the first wire. Fuse FU2 connects the second differential input end B of the RS485 module with the access terminal 300 through the second wire.
[0040] The first end of the first differential mode protection module 100 is connected between the fuse FU1 and the access terminal 300, and the second end of the first differential mode protection module 100 is connected between the fuse FU2 and the access terminal 300. The ground pin of the access terminal 300 is connected to the common ground.
[0041] The first end of the second differential mode protection module 200 is connected between the first differential input end A of the RS485 module and the fuse FU1, the second end of the second differential mode protection module 200 is connected between the second differential input end B of the RS485 module and the fuse FU2, and the third end of the second differential mode protection module 200 is connected to the common ground.
[0042] The access terminal 300 is used to access external differential mode surge voltage.
[0043] The first differential mode protection module 100 is used to discharge the external differential mode surge voltage, and the first differential mode voltage is output through the fuse FU1 and the fuse FU2. Since the first differential mode protection module 100 discharges the external differential mode surge voltage, the residual voltage between the differential mode surge voltages is reduced, so that the first differential mode voltage will not produce discharge behavior when passing through the fuse FU1 and the fuse FU2.
[0044] The second differential mode protection module 200 is used to discharge the first differential mode voltage, and outputs the second differential mode voltage to the RS485 module.
[0045] In this embodiment, by arranging the first differential mode protection module 100 at the front end of the two fuses, the external differential mode surge voltage entering the circuit is discharged by the first differential mode protection module 100, avoiding the discharge behavior of the external differential mode surge voltage when the two fuses are very close, and at the same time, the normal communication of the RS485 module is not negatively affected, and the circuit is protected.
[0046] Preferably, the distance between the fuse FU1 and the fuse FU2 is less than or equal to 0.6 mm, reducing the chip layout area.
[0047] More preferably, the lengths of the first wire and the second wire are equal to minimize the influence of common mode interference on the signal, and the line width and line spacing of the first wire and the second wire are strictly controlled according to actual needs to ensure impedance matching of the differential pair and reduce signal reflection and distortion.
[0048] As shown in Figure 2 The first differential mode protection module 100 includes a surge suppressor TSS3, a first end of the surge suppressor TSS3 is connected between the fuse FU1 and the access terminal 300; a second end of the surge suppressor TSS3 is connected between the fuse FU2 and the access terminal 300.
[0049] In this embodiment, by the surge suppressor TSS3 conducting rapidly when the surge voltage exceeds its threshold value, the surge energy is discharged, ensuring that the input voltage of the RS485 interface chip is within a safe range.
[0050] As shown in Figure 3 The second differential mode protection module 200 includes a surge suppressor TSS1 and a surge suppressor TSS2, a first end of the surge suppressor TSS1 is connected to the common ground, a second end of the surge suppressor TSS1 is connected between the first differential input end A of the RS485 module and the fuse FU1; a first end of the surge suppressor TSS2 is connected to the common ground, a second end of the surge suppressor TSS2 is connected between the second differential input end B of the RS485 module and the fuse FU2.
[0051] Preferably, the circuit further includes a common mode protection module 400, a first end of the common mode protection module 400 is connected between the fuse FU1 and the access terminal 300, a second end of the common mode protection module 400 is connected between the fuse FU2 and the access terminal 300, and a third end of the common mode protection module 400 is connected to the common ground.
[0052] The common mode protection module 400 is used for common mode signal filtering of the external differential mode surge voltage, and the filtered external differential mode surge voltage is input to the first differential mode protection module.
[0053] As shown in Figure 4 The common mode protection module 400 includes a capacitor C1 and a capacitor C2. One end of the capacitor C1 is connected between the fuse FU1 and the access terminal 300, and the other end of the capacitor C1 is connected to the common ground; one end of the capacitor C2 is connected between the fuse FU2 and the access terminal 300, and the other end of the capacitor C2 is connected to the common ground.
[0054] In this embodiment, the capacitor C1 and the capacitor C2 are used to filter the common mode signal existing in the line, avoiding the influence of the common mode signal on the RS485 module.
[0055] In one preferred embodiment, a differential mode surge protection circuit is provided, as shown in Figure 5As shown, including fuse FU1, fuse FU2, surge suppressor TSS1, surge suppressor TSS2, surge suppressor TSS3, capacitor C1, capacitor C2. The connection relationship and function of each component are as described in the above embodiments.
[0056] In one embodiment, a filter is provided, which includes the differential mode surge protection circuit described in the above embodiments. When the filter is connected with the RS485 module to work, the filter is placed as close to the interface chip of the RS485 module as possible, and through the grounding isolation measures, the line length between the filter and the chip is reduced, the influence of the line parasitic parameters on the filtering effect is reduced, at the same time, the interference of other circuits on the filter is also avoided, and the effectiveness of the filter is further enhanced.
[0057] In one embodiment, a photovoltaic energy controller is provided, which includes an RS485 module and a differential mode surge protection circuit as described in the above embodiments, and the RS485 module is connected with the differential mode surge protection circuit through the first wire and the second wire.
[0058] In the description of the present specification, the description referring to the terms "some embodiments", "other embodiments", and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily mean the same embodiment or example.
[0059] The technical features of the above-described embodiments can be combined arbitrarily, and in order to make the description simple, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.
[0060] The above-described embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as the limitation of the scope of the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.
Claims
1. A differential-mode surge protection circuit, said circuit being used in an RS485 module, characterized in that, The circuit includes: Fuse FU1 is connected to the first differential input terminal and the access terminal of the RS485 module via a first wire; Fuse FU2 is connected to the second differential input terminal of the RS485 module and the access terminal via a second wire; the access terminal is used to connect to an external differential surge voltage. The first differential mode protection module has a first end connected between the fuse FU1 and the access terminal, and a second end connected between the fuse FU2 and the access terminal; the first differential mode protection module is used to surge discharge the external differential mode surge voltage and output a first differential mode voltage through the fuse FU1 and the fuse FU2. The second differential mode protection module has its first terminal connected between the first differential input terminal of the RS485 module and the fuse FU1, its second terminal connected between the second differential input terminal of the RS485 module and the fuse FU2, and its third terminal connected to a common ground. The second differential mode protection module is used to surge-damp the first differential mode voltage and output a second differential mode voltage to the RS485 module.
2. The differential mode surge protection circuit according to claim 1, characterized in that, The first differential mode protection module includes a surge suppressor TSS3. The first end of the surge suppressor TSS3 is connected between the fuse FU1 and the access terminal; the second end of the surge suppressor TSS3 is connected between the fuse FU2 and the access terminal.
3. The differential mode surge protection circuit according to claim 1, characterized in that, The second differential mode protection module includes surge suppressor TSS1 and surge suppressor TSS2. The first end of the surge suppressor TSS1 is connected to the common ground, and the second end of the surge suppressor TSS1 is connected between the first differential input terminal of the RS485 module and the fuse FU1. The first end of the surge suppressor TSS2 is connected to the common ground, and the second end of the surge suppressor TSS2 is connected between the second differential input terminal of the RS485 module and the fuse FU2.
4. The differential mode surge protection circuit according to claim 1, characterized in that, The circuit also includes a common-mode protection module. The first terminal of the common-mode protection module is connected between the fuse FU1 and the access terminal. The second terminal of the common-mode protection module is connected between the fuse FU2 and the access terminal. The third terminal of the common-mode protection module is connected to a common ground. The common-mode protection module is used to perform common-mode signal filtering on the external differential-mode surge voltage, and input the filtered external differential-mode surge voltage into the first differential-mode protection module.
5. The differential mode surge protection circuit according to claim 4, characterized in that, The common-mode protection module includes capacitor C1 and capacitor C2. One end of the capacitor C1 is connected between the fuse FU1 and the access terminal, and the other end of the capacitor C1 is connected to the common ground; One end of the capacitor C2 is connected between the fuse FU2 and the access terminal, and the other end of the capacitor C2 is connected to the common ground.
6. The differential mode surge protection circuit according to claim 1, characterized in that, The distance between fuse FU1 and fuse FU2 is less than or equal to 0.6 mm.
7. The differential mode surge protection circuit according to claim 1, characterized in that, The first conductor and the second conductor are of equal length.
8. The differential mode surge protection circuit according to claim 1, characterized in that, The grounding pin of the access terminal is connected to the common ground.
9. A filter, characterized in that, The filter includes a differential mode surge protection circuit as described in any one of claims 1 to 8.
10. A photovoltaic energy controller, characterized in that, The photovoltaic energy controller includes an RS485 module and a differential mode surge protection circuit as described in any one of claims 1 to 8, wherein the RS485 module and the differential mode surge protection circuit are connected via a first wire and a second wire.