Modularized power supply filtering device

Abstract

The invention discloses a modularized power supply filtering device, which not only realizes fine lightning protection and improves EMI filtering effect, but also realizes modularization, miniaturization and convenient installation. The lightning protection circuit comprises an LP lightning protection circuit module and an EMI filter circuit module. The LP lightning protection circuit module and the EMI filter circuit module are arranged on the same circuit board; the LP lightning protection circuit module is provided with a first-stage protection circuit unit and a second-stage protection circuit unit, the first-stage protection circuit unit is used for discharging and preventing large lightning stroke energy, and the second-stage protection circuit unit is used for further discharging and preventing the lightning stroke energy; the EMI filter circuit module is provided with an adjusting screw, and the adjusting screw is used for dynamically adjusting the filter circuit and the cut-off frequency.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of filtering equipment, and in particular to a modular power supply filtering device. Background Art

[0002] A filter is a filter circuit composed of capacitors, inductors and resistors. It is a device or circuit network structure that has a corresponding processing function on the signal, and only effectively filters out specific frequencies in the power line, and obtains a desired frequency signal at the output end.

[0003] However, existing filtering protection equipment, such as lightning suppressors, EMI filters, etc., have single functions, large volumes, poor filtering protection effects, and cannot be well adapted to products. Using a single-stage structure, the filtering and protection effects are poor; using a double-stage structure, the two filters are installed independently and connected by leads, which is not only inconvenient to install, but also cannot achieve a good filtering protection effect. Summary of the invention

[0004] The present application provides a modular power supply filtering device, which not only realizes refined lightning protection and improves EMI filtering effect, but also realizes modularization, miniaturization and easy installation.

[0005] The embodiment of the present application provides a modular power supply filtering device, including:

[0006] LP lightning protection circuit module and EMI filter circuit module;

[0007] The LP lightning protection circuit module and the EMI filter circuit module are arranged on the same circuit board;

[0008] The LP lightning protection circuit module is provided with a primary protection circuit unit and a secondary protection circuit unit, wherein the primary protection circuit unit is used to discharge and prevent large lightning strike energy, and the secondary protection circuit unit is used to further discharge and prevent lightning strike energy;

[0009] The EMI filter circuit module is provided with an adjusting screw, and the adjusting screw is used to dynamically adjust the filter circuit and the cut-off frequency.

[0010] Optionally, the EMI filter circuit module is further provided with an EMI filter circuit unit, and the EMI filter circuit unit includes a plurality of common-mode capacitors and a plurality of common-mode inductors, and the plurality of common-mode capacitors and the plurality of common-mode inductors are used to suppress common-mode interference.

[0011] Optionally, the EMI filtering circuit unit further includes a plurality of differential mode capacitors, and the plurality of differential mode capacitors are used to suppress differential mode interference.

[0012] Optionally, the EMI filter circuit unit further includes a source impedance and a load impedance, and the filter circuit and the cutoff frequency can be adjusted by adjusting the resistance values ​​of the source impedance and the load impedance.

[0013] Optionally, the adjusting screw includes a circuit adjusting screw and a frequency adjusting screw, the circuit adjusting screw is used to adjust the topology of the filter circuit, and the frequency adjusting screw is used to adjust the cut-off frequency.

[0014] Optionally, the EMI filter circuit module is provided with a shell, and the shell is used to protect the EMI filter circuit module.

[0015] Optionally, the first-level protection circuit unit is provided with a plurality of varistors, and the plurality of varistors are used to protect subsequent circuits.

[0016] Optionally, the first-level protection circuit unit is provided with a plurality of discharge tubes, and the plurality of discharge tubes are used to protect the subsequent circuit.

[0017] Optionally, the secondary protection circuit unit is provided with a plurality of transient diodes, and the plurality of transient diodes are used to protect components from damage.

[0018] Optionally, a decoupling inductor is connected in series between the primary protection circuit unit and the secondary protection circuit unit, and the decoupling inductor is used to delay the time for a lightning strike signal to travel from the primary protection circuit unit to the secondary protection circuit unit.

[0019] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0020] In this application, a modular power supply filter device is designed, including an LP lightning protection circuit module and an EMI filter circuit module. The two modules cooperate with each other to enhance EMI filtering and lightning protection. The LP lightning protection circuit module is provided with a two-stage protection circuit to achieve refined lightning protection; the EMI filter circuit module is provided with an adjustment screw to achieve adjustable filter circuit and cutoff frequency, improve the EMI filtering effect, and adapt to different application environments. At the same time, the two modules are integrated on a circuit board, which also realizes modularization, miniaturization, and easy installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is an internal view of a modular power supply filter device in an embodiment of the present application;

[0022] Figure 2 This is a schematic diagram of the structure of the EMI filter circuit module in the embodiment of the present application;

[0023] Figure 3 This is a circuit schematic diagram of an EMI filter circuit unit in an embodiment of the present application;

[0024] Figure 4 1 is a circuit schematic diagram of a two-stage protection circuit unit in the LP lightning protection circuit module in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only used to illustrate the relative positional relationships between the various components or components, and do not particularly limit the specific installation orientations of the various components or components.

[0026] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0027] In addition, the terms "installed", "set", "provided with", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0028] In addition, the structures, proportions, sizes, etc. drawn in the drawings in the present application are only used to match the contents disclosed in the specification for the technical personnel in this field to understand and read, and are not used to limit the restrictive conditions under which the present application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present application without affecting the effects and purposes that can be achieved by the present application.

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] The present application provides a modular power supply filtering device, which not only realizes refined lightning protection and improves EMI filtering effect, but also realizes modularization, miniaturization and easy installation.

[0031] It should be noted that the description of the modular power filter device in this application is based on Figure 1 For reference, Figure 1 In the figure, the LP lightning protection circuit module is located on the left, and the EMI filtering circuit module is located on the right.

[0032] See also Figures 1 to 4 , the embodiment of the present application provides a modular power supply filtering device, including:

[0033] LP lightning protection circuit module 1 and EMI filter circuit module 2;

[0034] The LP lightning protection circuit module 1 and the EMI filter circuit module 2 are arranged on the same circuit board 3;

[0035] The LP lightning protection circuit module 1 is provided with a primary protection circuit unit 11 and a secondary protection circuit unit 12. The primary protection circuit unit 11 is used to discharge and prevent large lightning strike energy, and the secondary protection circuit unit 12 is used to further discharge and prevent lightning strike energy.

[0036] The EMI filter circuit module 2 is provided with an adjustment screw 21, and the adjustment screw 21 is used to dynamically adjust the filter circuit and the cut-off frequency.

[0037] It should be noted that in order to solve the problems of conventional lightning suppressors and EMI filters, such as single function, large size and poor filtering protection effect, a modular power supply filtering device mainly for military, aviation and other fields is designed in the embodiment of the present application, so that it can simultaneously meet the requirements of military equipment such as GJB151B, CE102, RE102 and aviation power electronic equipment such as DO160G and Sec22.

[0038] The device includes two partial functional circuits, an LP lightning protection circuit module 1 and an EMI filtering circuit module 2. The two modules are integrated on a circuit board. The output end of the LP lightning protection circuit module 1 is connected to the input end of the EMI filtering circuit module 2. The output end of the EMI filtering circuit module 2 is connected to the switching power supply circuit and the load circuit in sequence. The two modules cooperate with each other to enhance EMI filtering and lightning protection, while also achieving modularization, miniaturization and easy installation.

[0039] Specifically, the LP lightning protection circuit module 1 is provided with two-level protection circuits, namely, a first-level protection circuit unit 11 and a second-level protection circuit unit 12. The first-level protection circuit is used to discharge large energy, and the second-level protection circuit is used to achieve refined protection. The EMI filter circuit module 2 is provided with an adjustment screw 21, which is used to achieve the adjustable filter circuit and cutoff frequency, and to adjust to different filter circuits such as L-type, T-type, and π-type to adapt to different application environments, so as to achieve a good EMI filtering effect when a filter is applied to different products.

[0040] In the embodiment of the present application, a modular power supply filter device is designed, including an LP lightning protection circuit module 1 and an EMI filter circuit module 2. The two modules cooperate with each other to enhance EMI filtering and lightning protection. Among them, the LP lightning protection circuit module 1 is provided with a two-stage protection circuit to achieve refined lightning protection; the EMI filter circuit module 2 is provided with an adjustment screw 21 to achieve adjustable filtering circuit and cutoff frequency, improve EMI filtering effect, and adapt to different application environments. At the same time, the two modules are integrated on a circuit board, which also realizes modularization, miniaturization, and easy installation.

[0041] Optionally, the EMI filter circuit module 2 is further provided with an EMI filter circuit unit 22, and the EMI filter circuit unit 22 includes a plurality of common-mode capacitors and a plurality of common-mode inductors, and the plurality of common-mode capacitors and the plurality of common-mode inductors are used to suppress common-mode interference.

[0042] In the embodiment of the present application, the EMI filter circuit module 2 is further provided with an EMI filter circuit unit 22 for implementing EMI filtering. The EMI filter circuit unit 22 is mainly composed of simple components such as capacitors and inductors. Figure 3 As shown, the EMI filter circuit unit 22 is provided with six common-mode capacitors CY11, CY22, CY33, CY44, CY55, and CY66 and two common-mode inductors L1 and L2 for suppressing common-mode interference.

[0043] It should be noted that L1 and L2 have no effect on series mode interference. Only when common mode interference occurs, the total inductance increases rapidly after coupling due to the same magnetic flux direction of the two coils, which has a large impedance to the common mode signal and makes it difficult to pass. CY11, CY22, CY33, CY44, CY55, and CY66 use film capacitors, which are connected in pairs between the two power lines and the ground (LE, NE), which can effectively suppress common mode interference. And the midpoint of the capacitor is connected to the ground, and by controlling the on and off of the capacitor grounding, and cooperating with the common mode inductors L1 and L2, it is also possible to achieve the adjustment of different filter circuits and cutoff frequencies.

[0044] Optionally, the EMI filtering circuit unit 22 further includes a plurality of differential mode capacitors, and the plurality of differential mode capacitors are used to suppress differential mode interference.

[0045] In the embodiment of the present application, the EMI filter circuit unit 22 is also provided with three differential mode capacitors CX1, CX2, and CX3 for suppressing differential mode interference. The differential mode is also called the series mode, which refers to the signal difference between two lines.

[0046] like Figure 3 As shown, CX1, CX2, and CX3 all use film capacitors, which are connected across the two lines (LN) of the power line to suppress differential mode interference.

[0047] It should be noted that the capacitance value of the common-mode capacitor cannot be too large. Generally, the differential-mode capacitor is in the uF level, and the common-mode capacitor is in the nF level.

[0048] Optionally, the EMI filter circuit unit 22 further includes a source impedance and a load impedance, and the filter circuit and the cutoff frequency can be adjusted by adjusting the resistance values ​​of the source impedance and the load impedance.

[0049] It should be noted that, in the embodiment of the present application, the EMI filter circuit unit 22 is also connected to the switching power supply circuit and the load circuit, and it cooperates with the end source impedance in the switching power supply circuit and the load impedance in the load circuit to realize the adjustment of the filter circuit and the cutoff frequency. Specifically, the adjustment of different filter circuits and cutoff frequencies is realized by changing the values ​​of the source impedance and the load impedance.

[0050] Optionally, the adjusting screw 21 includes a circuit adjusting screw 211 and a frequency adjusting screw 212 , wherein the circuit adjusting screw 211 is used to adjust the topology of the filter circuit, and the frequency adjusting screw 212 is used to adjust the cutoff frequency.

[0051] It should be noted that in the embodiment of the present application, the EMI filter circuit module 2 realizes the adjustable filter circuit and cutoff frequency through the adjustment screw 21. Specifically, the topology of the filter circuit is adjusted through the circuit adjustment screw 211 to achieve mismatch termination and achieve a good filtering effect; the insertion loss is adjusted through the frequency adjustment screw 212 to adapt to different application environments.

[0052] Optionally, the EMI filter circuit module 2 is provided with a housing 23 , and the housing 23 is used to protect the EMI filter circuit module 2 .

[0053] Optionally, the first-level protection circuit unit 11 is provided with a plurality of varistors, and the plurality of varistors are used to protect subsequent circuits.

[0054] Optionally, the primary protection circuit unit 11 is provided with a plurality of discharge tubes, and the plurality of discharge tubes are used to protect the subsequent circuit.

[0055] It should be noted that the gas discharge tube GDT is a switch-type protection device, and its working principle is gas discharge. When the voltage between the two poles is large enough, the gap between the poles will be broken down by the discharge, and the original insulating state will be converted into a conductive state, similar to a short circuit. In the conductive state, the voltage maintained between the two poles is very low, generally between 20 and 50V, so it can protect the subsequent circuit.

[0056] Varistor is a voltage-limiting protection device. It uses the nonlinear characteristics of varistor. When overvoltage appears between the two poles of varistor, varistor can clamp the voltage to a relatively fixed voltage value, thereby protecting the subsequent circuit. Varistor can be mainly used in DC power supply, AC power supply, low-frequency signal line, and antenna feeder line with feeder.

[0057] Varistors and gas discharge tubes (lightning protection diodes) are both lightning protection overvoltage protection components and are widely used in lightning protection of electronic equipment.

[0058] See also Figure 4 In the embodiment of the present application, three varistors VR1, VR2, VR3 and two discharge tubes GDT1, GDT3 are provided, wherein VR3 and GDT3 are connected in series between two power lines, and VR1 and VR2 are connected in parallel with GDT1 in series between the line and the ground, together forming a primary protection circuit unit to absorb larger surges and discharge large energy.

[0059] Optionally, the secondary protection circuit unit 12 is provided with a plurality of transient diodes, and the plurality of transient diodes are used to protect components from being damaged.

[0060] See also Figure 4 In the embodiment of the present application, a two-stage protection design is adopted. The first stage is used to absorb larger surges, and the second stage uses TVS (transient suppression diode) to further absorb the residual pressure.

[0061] When TVS diodes are subjected to instantaneous high-energy pulses, they can change from the original high impedance state to low impedance in a very short time, and clamp the voltage to a specific level, thereby effectively protecting the user's equipment and components from damage. Because of its low clamping voltage and fast action time, it is more suitable for the final protection of multi-level protection circuits.

[0062] In the embodiment of the present application, three transient diodes, TVS1, TVS2 and TVS3, are provided, wherein TVS3 is connected between two power lines, and TVS1 and TVS2 are connected in parallel between the line and the ground, so as to realize refined protection.

[0063] Optionally, a decoupling inductor is connected in series between the primary protection circuit unit 11 and the secondary protection circuit unit 12 , and the decoupling inductor is used to delay the time for the lightning strike signal to travel from the primary protection circuit unit 11 to the secondary protection circuit unit 12 .

[0064] like Figure 4 As shown, it should be noted that, of the two-stage lightning arrester, the front stage has a large discharge flow, but slow action, while the rear stage is close to the load end, mainly to discharge the residual pressure of the front stage, with a small discharge flow and sensitive action.

[0065] Therefore, in order to delay the time when the subsequent lightning strike signal reaches the next stage, the embodiment of the present application connects a decoupling inductor in series between the first-level protection circuit unit 11 and the second-level protection circuit unit 12 to delay the arrival time of the lightning strike.

[0066] In addition, in the present application, TVS1 and TVS2 to ground and decoupling inductors L3 and L4 are used to supplement EMI filtering.

[0067] It should be noted that the above description of the disclosed embodiments enables professionals in the field to implement or use the present application. Various modifications to these embodiments will be apparent to professionals in the field, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A modular power supply filter device, It is characterized in that include: LP lightning protection circuit module and EMI filter circuit module; The LP lightning protection circuit module and the EMI filter circuit module are arranged on the same circuit board; The LP lightning protection circuit module is provided with a primary protection circuit unit and a secondary protection circuit unit, wherein the primary protection circuit unit is used to discharge and prevent large lightning strike energy, and the secondary protection circuit unit is used to further discharge and prevent lightning strike energy; The EMI filter circuit module is provided with an adjusting screw, and the adjusting screw is used to dynamically adjust the filter circuit and the cut-off frequency.

2. The power supply filter device according to claim 1, It is characterized in that The EMI filter circuit module is also provided with an EMI filter circuit unit, and the EMI filter circuit unit includes a plurality of common-mode capacitors and a plurality of common-mode inductors, and the plurality of common-mode capacitors and the plurality of common-mode inductors are used to suppress common-mode interference.

3. The power supply filter device according to claim 2, It is characterized in that The EMI filter circuit unit also includes a plurality of differential mode capacitors, and the plurality of differential mode capacitors are used to suppress differential mode interference.

4. The power supply filter device according to claim 2, It is characterized in that The EMI filter circuit unit also includes a terminal source impedance and a load impedance, and the filter circuit and the cut-off frequency can be adjusted by adjusting the resistance values ​​of the terminal source impedance and the load impedance.

5. The power supply filter device according to claim 1, It is characterized in that The adjusting screw comprises a circuit adjusting screw and a frequency adjusting screw. The circuit adjusting screw is used to adjust the topology of the filter circuit, and the frequency adjusting screw is used to adjust the cut-off frequency.

6. The power supply filter device according to any one of claims 1 to 5, It is characterized in that The EMI filter circuit module is provided with a shell, and the shell is used to protect the EMI filter circuit module.

7. The power supply filter device according to any one of claims 1 to 5, It is characterized in that The primary protection circuit unit is provided with a plurality of varistors, and the plurality of varistors are used to protect the subsequent circuit.

8. The power supply filter device according to any one of claims 1 to 5, It is characterized in that The primary protection circuit unit is provided with a plurality of discharge tubes, and the plurality of discharge tubes are used to protect the subsequent circuit.

9. The power supply filter device according to any one of claims 1 to 5, It is characterized in that The secondary protection circuit unit is provided with a plurality of transient diodes, and the plurality of transient diodes are used to protect components from being damaged.

10. The power supply filter device according to any one of claims 1 to 5, It is characterized in that A decoupling inductor is connected in series between the primary protection circuit unit and the secondary protection circuit unit, and the decoupling inductor is used to delay the time for a lightning strike signal to travel from the primary protection circuit unit to the secondary protection circuit unit.

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