Miniaturized electromagnetic protection circuit and device for 24V direct-current power line

Abstract

The invention discloses a miniaturized electromagnetic protection circuit and device for a 24V direct-current power line, and relates to the technical field of electromagnetic protection. The electromagnetic protection circuit is composed of an electromagnetic protection module and a filtering module, and specifically comprises a common mode inductor, a gas discharge tube, three transient suppression diodes, a common mode transient suppression diode, three piezoresistors, two differential mode capacitors, four common mode capacitors and two resistors. The electromagnetic protection device based on the electromagnetic protection circuit further comprises a shell and a connector. The protection circuit is arranged to suppress high-energy pulses, the protection capability of the circuit on external high-energy impacts can be effectively improved, meanwhile, the filtering system is used for filtering high-frequency noise, and the electromagnetic compatibility of the power supply and the stability of output voltage can be effectively improved; compared with an existing circuit, the electromagnetic protection circuit has the advantages that the number of electronic elements is reduced, and miniaturization of the electromagnetic protection device is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic protection, and in particular to a miniaturized electromagnetic protection circuit and device for a 24V DC power line. Background Art

[0002] In modern society, whether it's communications, computers, industrial control, or transportation, power systems are essential. As the "heart" of electronic equipment, power systems are crucial for providing stable power to various devices.

[0003] A high-quality power supply system ensures the proper functioning of equipment and prevents malfunctions or damage caused by voltage fluctuations. Furthermore, the stability of the power supply system is directly related to its overall performance and is the cornerstone of an efficient and stable power supply. However, with the increasing prevalence of electronic devices and the widespread use of wireless communications, the electromagnetic environment is becoming increasingly complex, and electromagnetic radiation is becoming increasingly prominent, potentially damaging the power supply system. Therefore, electromagnetic protection for power lines can ensure that the power supply system maintains normal and stable operation in various complex electromagnetic environments. Furthermore, with the increasing integration of electronic devices, miniaturization of protective devices is also necessary. Summary of the Invention

[0004] In response to the problems pointed out in the background technology, the present invention provides a miniaturized electromagnetic protection circuit and device for 24V DC power lines that can effectively protect against high-energy electromagnetic pulses, solving the problem in the related technology that the power supply system cannot work normally due to interference from external electromagnetic pulses.

[0005] A miniaturized electromagnetic protection circuit for a 24V DC power line, characterized by comprising an electromagnetic protection module;

[0006] The electromagnetic protection module comprises a common-mode inductor (212), a gas discharge tube (24), a differential-mode transient suppression diode (219), a first common-mode transient suppression diode (213), a second common-mode transient suppression diode (214), a first varistor (25), and a second varistor (26);

[0007] The common mode inductor L in Connect the positive input terminal, N in Connect the negative input terminal, L out Connect the positive output terminal, N outThe first varistor has one end connected to the positive input terminal, and the other end connected to the first end of the gas discharge tube; the second end of the gas discharge tube is grounded, and the third end is connected to the second varistor; the other end of the second varistor is connected to the negative input terminal; the differential mode transient suppression diode has one end connected to the positive output terminal, and the other end connected to the negative output terminal; the first common mode transient suppression diode has one end connected to the positive output terminal, and the other end connected to the second common mode transient suppression diode, and a ground node is provided between the two common mode transient suppression diodes; the other end of the second common mode transient suppression diode is connected to the negative output terminal.

[0008] Furthermore, the electromagnetic protection circuit further includes a filtering module;

[0009] The filtering module comprises a third varistor (211), a first differential mode capacitor (27), a second differential mode capacitor (215), a first common mode capacitor (28), a second common mode capacitor (29), a third common mode capacitor (216), a fourth common mode capacitor (217), a first resistor (210), and a second resistor (218); wherein one end of the third varistor, the first differential mode capacitor, and the first resistor are connected to the positive input terminal, and the other ends are connected to the negative input terminal; one end of the first common mode capacitor is connected to the positive input terminal, and the other end is connected to the second common mode capacitor; the other end of the second common mode capacitor is connected to the negative input terminal; one end of the second differential mode capacitor and the second resistor are connected to the positive output terminal, and the other ends are connected to the negative output terminal; one end of the third common mode capacitor is connected to the positive output terminal, and the other end is connected to the fourth common mode capacitor, and a grounding node is provided between the two common mode capacitors; the other end of the fourth common mode capacitor is connected to the negative output terminal.

[0010] Furthermore, the electromagnetic protection device based on the electromagnetic protection circuit further includes a housing (1) and a connector (3);

[0011] The housing (1) is an electromagnetic shielding enclosure formed of metal panels; the left and right sides of the housing are interface panels, and the interface panels are provided with connectors (3);

[0012] The electromagnetic protection circuit (2) is placed inside the housing and is connected to an external power line via a connector (3).

[0013] Furthermore, one of the connectors (3) is provided with a positive input terminal (21), a negative input terminal (22), and a ground terminal (23); and the other connector (3) is provided with a positive output terminal (220), a negative output terminal (221), and a ground terminal (23).

[0014] Furthermore, the front and rear side panels of the shell are provided with a plurality of heat dissipation holes.

[0015] Furthermore, the differential mode transient suppression diode (219), the first common mode transient suppression diode (213), the second common mode transient suppression diode (214), the first resistor (210), the second resistor (218), the first common mode capacitor (28), the second common mode capacitor (29), the third common mode capacitor (216), and the fourth common mode capacitor (217) are implemented using chip components.

[0016] Furthermore, the lower panel or the upper panel of the shell is a movable cover, which is convenient for installation and maintenance.

[0017] The working principle of the present invention is as follows:

[0018] When electromagnetic pulse interference enters, the common-mode inductor will change to a high-impedance state as the frequency increases, preventing the electromagnetic pulse from passing through. In this case, the voltage across the common-mode inductor will increase to the operating voltage of the varistor (25, 26), and the varistor (25, 26) in the front-stage branch of the common-mode inductor will change from an open-circuit state to a short-circuit state. The gas discharge tube (24) will be broken down under the high-voltage state. The varistor (25, 26) and the gas discharge tube (24) together form a low-impedance first-stage discharge circuit. Most of the electromagnetic pulse energy is discharged to the ground through the varistor-gas discharge tube branch, and a small part of the residual electromagnetic pulse energy enters the back-stage circuit through the common-mode inductor. When facing some high-frequency signals that are too fast, the first-stage discharge circuit has no time to react. Therefore, three transient suppression diodes are used after the common-mode inductor to perform a second-stage clamping (second-stage discharge), which plays a secondary discharge role, making the clamping voltage lower than the withstand voltage of the power supply, thereby allowing the power supply to maintain normal operation in a complex electromagnetic environment. The remaining electromagnetic pulse energy is filtered out by the filtering module, preventing interference such as high-power continuous wave pulses and nuclear pulses from entering the back end of the system, thereby achieving protection for subsequent circuits.

[0019] Compared with the prior art, the advantages of the present invention are:

[0020] 1. The present invention reduces the number of electronic components by improving the existing electromagnetic protection circuit, reduces the volume of the circuit by selecting devices, and increases the space utilization of the circuit board by rationally arranging the electronic components. This improves the electromagnetic protection performance while reducing the space occupied by the circuit board, thereby realizing the miniaturization of the electromagnetic protection device.

[0021] 2. The present invention optimizes the cavity of the electromagnetic protection device and sets heat dissipation holes to improve the heat dissipation performance. At the same time, the installation position of the internal circuit board and the connector is optimized to improve the electromagnetic protection performance while optimizing the volume of the component.

[0022] 3. The present invention suppresses high-energy pulses through an electromagnetic protection circuit, which can effectively improve the circuit's protection capability against external high-energy impacts. At the same time, the use of a filtering system to filter high-frequency noise can effectively improve the electromagnetic compatibility of the power supply and the stability of the output voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Figure 1 This is a schematic structural diagram of a miniaturized electromagnetic protection device for a 24V DC power line in an embodiment;

[0025] Figure 2 This is a circuit diagram of a miniaturized electromagnetic protection circuit module for a 24V DC power line in an embodiment;

[0026] Figure 3 This is a circuit diagram of a miniaturized electromagnetic protection circuit (including a filter module) for a 24V DC power line in an embodiment; DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0028] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting this application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0029] A miniaturized electromagnetic protection device for 24V DC power lines, such as Figure 1 As shown, it includes a housing (1), an electromagnetic protection circuit (2), and a connector (3).

[0030] The housing (1) is an electromagnetic shielding enclosure formed of metal panels; the left and right side panels of the housing are interface panels, on which connectors (3) are provided; the front and rear side panels are provided with a plurality of heat dissipation holes; and the side panels are movable covers for easy installation and maintenance.

[0031] The electromagnetic protection circuit (2) is placed inside the housing and connected to an external power line via a connector (3). The left connector (3) is provided with a positive input terminal (21), a negative input terminal (22), and a ground terminal (23); the right connector (3) is provided with a positive output terminal (220), a negative output terminal (221), and a ground terminal (23).

[0032] The electromagnetic protection circuit (2) comprises an electromagnetic protection module and a filtering module;

[0033] The electromagnetic protection module, such as Figure 2 and 3 As shown, it includes a common-mode inductor (212), a gas discharge tube (24), a differential-mode transient suppression diode (219), a first common-mode transient suppression diode (213), a second common-mode transient suppression diode (214), a first varistor (25), and a second varistor (26).

[0034] The common mode inductor L in Connect the positive input terminal, N in Connect the negative input terminal, L out Connect the positive output terminal, N out The first varistor has one end connected to the positive input terminal, and the other end connected to the first end of the gas discharge tube; the second end of the gas discharge tube is grounded, and the third end is connected to the second varistor; the other end of the second varistor is connected to the negative input terminal; the differential mode transient suppression diode has one end connected to the positive output terminal, and the other end connected to the negative output terminal; the first common mode transient suppression diode has one end connected to the positive output terminal, and the other end connected to the second common mode transient suppression diode, and a ground node is provided between the two common mode transient suppression diodes; the other end of the second common mode transient suppression diode is connected to the negative output terminal.

[0035] In the electromagnetic protection module, a gas discharge tube is used to discharge the input high-power pulses; a first varistor and a second varistor are connected in series at both ends of the gas discharge tube to reduce the gas discharge tube's freewheeling problem. Three transient suppression diodes are used to filter common-mode interference between lines and grounds, as well as differential-mode interference between lines. In this embodiment, the electromagnetic protection circuit, under high-power pulse injection conditions, can perform primary discharge through the gas discharge tube and varistor, and use three transient suppression diodes for secondary clamping, reducing the clamping voltage to below the power supply's withstand voltage, thereby enabling the power supply to maintain normal operation in complex electromagnetic environments.

[0036] The filtering module, such as Figure 3 As shown, it includes a third varistor (211), a first differential mode capacitor (27), a second differential mode capacitor (215), a first common mode capacitor (28), a second common mode capacitor (29), a third common mode capacitor (216), a fourth common mode capacitor (217), a first resistor (210), and a second resistor (218).

[0037] One end of the third varistor, the first differential mode capacitor, and the first resistor are connected to the positive input terminal, and the other end is connected to the negative input terminal; one end of the first common mode capacitor is connected to the positive input terminal, and the other end is connected to the second common mode capacitor; the other end of the second common mode capacitor is connected to the negative input terminal; one end of the second differential mode capacitor and the second resistor are connected to the positive output terminal, and the other end is connected to the negative output terminal; one end of the third common mode capacitor is connected to the positive output terminal, and the other end is connected to the fourth common mode capacitor, and a ground node is provided between the two common mode capacitors; the other end of the fourth common mode capacitor is connected to the negative output terminal.

[0038] Specifically, in this embodiment, the parameters of the important circuit components are as follows:

[0039] Gas discharge tube (24): model 3RM230L-8;

[0040] Varistor (25, 26): varistor voltage 120V;

[0041] Varistor (211): varistor voltage 82V;

[0042] Differential mode capacitor (27): 2.2uF X2 safety capacitor;

[0043] Differential mode capacitor (215): 0.68uF X2 safety capacitor;

[0044] Common mode capacitors (28, 29, 216, 217): 3300pF, withstand voltage 500V;

[0045] Resistors (210, 218): Model RY21B-2W-1MΩ;

[0046] Common mode inductor (212): inductance 1mH, current 40A;

[0047] Transient voltage suppressor diodes (213, 214, 219): TVS diodes with a clamping voltage of 36V;

[0048] In the filtering module, the first differential-mode capacitor, the first common-mode capacitor, the second common-mode capacitor, the first resistor, and the third varistor are located at the input end of the common-mode inductor, while the second differential-mode capacitor, the third common-mode capacitor, the fourth common-mode capacitor, and the second resistor are located at the output end of the common-mode inductor. In this embodiment, the common-mode inductor and the common-mode capacitors can effectively filter out common-mode high-frequency noise interference from the source ground; the two differential-mode capacitors and the third varistor can effectively filter out differential-mode interference from power lines; and the two parallel resistors can effectively prevent residual charge in the differential-mode capacitors from damaging the circuit.

[0049] In this embodiment, the differential mode transient suppression diode (219), the first common mode transient suppression diode (213), the second common mode transient suppression diode (214), the first resistor (210), the second resistor (218), the first common mode capacitor (28), the second common mode capacitor (29), the third common mode capacitor (216), and the fourth common mode capacitor (217) are implemented using chip components, thereby reducing the area of ​​the circuit board and, combined with the design of the protection circuit, achieving miniaturization of the electromagnetic protection device.

[0050] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A miniaturized electromagnetic protection circuit for a 24V DC power line, characterized in that: Including electromagnetic protection module; The electromagnetic protection module comprises a common-mode inductor (212), a gas discharge tube (24), a differential-mode transient suppression diode (219), a first common-mode transient suppression diode (213), a second common-mode transient suppression diode (214), a first varistor (25), and a second varistor (26); The common mode inductance L in Connect the positive input terminal, N in Connect the negative input terminal, L out Connect the positive output terminal, N out The first varistor has one end connected to the positive input terminal, and the other end connected to the first end of the gas discharge tube; the second end of the gas discharge tube is grounded, and the third end is connected to the second varistor; the other end of the second varistor is connected to the negative input terminal; one end of the differential mode transient suppression diode is connected to the positive output terminal, and the other end is connected to the negative output terminal; one end of the first common mode transient suppression diode is connected to the positive output terminal, and the other end is connected to the second common mode transient suppression diode, and a grounding node is provided between the two common mode transient suppression diodes; the other end of the second common mode transient suppression diode is connected to the negative output terminal.

2. A miniaturized electromagnetic protection circuit for a 24V DC power line as claimed in claim 1, characterized in that: The electromagnetic protection circuit also includes a filtering module; The filtering module comprises a third varistor (211), a first differential mode capacitor (27), a second differential mode capacitor (215), a first common mode capacitor (28), a second common mode capacitor (29), a third common mode capacitor (216), a fourth common mode capacitor (217), a first resistor (210), and a second resistor (218); wherein one end of the third varistor, the first differential mode capacitor, and the first resistor are connected to the positive input end, and the other ends are connected to the negative input end; one end of the first common mode capacitor is connected to the positive input end, and the other end is connected to the second common mode capacitor; the other end of the second common mode capacitor is connected to the negative input end; one end of the second differential mode capacitor and the second resistor are connected to the positive output end, and the other ends are connected to the negative output end; one end of the third common mode capacitor is connected to the positive output end, and the other end is connected to the fourth common mode capacitor, and a grounding node is provided between the two common mode capacitors; the other end of the fourth common mode capacitor is connected to the negative output end.

3. A miniaturized electromagnetic protection circuit for a 24V DC power line as claimed in claim 1 or 2, characterized in that: An electromagnetic protection device based on an electromagnetic protection circuit also includes a housing (1) and a connector (3); The housing (1) is an electromagnetic shielding enclosure formed of a metal panel; the left and right sides of the housing are interface panels, and the interface panels are provided with connectors (3); The electromagnetic protection circuit (2) is placed inside the housing and is connected to an external power line via a connector (3).

4. A miniaturized electromagnetic protection circuit for a 24V DC power line as claimed in claim 3, characterized in that: One of the connectors (3) is provided with a positive input terminal (21), a negative input terminal (22), and a ground terminal (23); the other connector (3) is provided with a positive output terminal (220), a negative output terminal (221), and a ground terminal (23).

5. A miniaturized electromagnetic protection circuit for a 24V DC power line as claimed in claim 4, characterized in that: The front and rear side panels of the shell are provided with a plurality of heat dissipation holes.

6. A miniaturized electromagnetic protection circuit for a 24V DC power line as claimed in claim 4, characterized in that: The differential mode transient suppression diode (219), the first common mode transient suppression diode (213), the second common mode transient suppression diode (214), the first resistor (210), the second resistor (218), the first common mode capacitor (28), the second common mode capacitor (29), the third common mode capacitor (216), and the fourth common mode capacitor (217) are implemented using chip components.

7. A miniaturized electromagnetic protection circuit for a 24V DC power line as claimed in claim 5, characterized in that: The lower side panel or the upper side panel of the shell is a movable cover plate.

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