CN109509607B

CN109509607B - filter

Info

Publication number: CN109509607B
Application number: CN201811646720.XA
Authority: CN
Inventors: 王晶鑫; 戴书林
Original assignee: Hefei Meyer Optoelectronic Technology Inc
Current assignee: Hefei Meyer Optoelectronic Technology Inc
Priority date: 2018-12-29
Filing date: 2018-12-29
Publication date: 2023-11-17
Anticipated expiration: 2038-12-29
Also published as: CN109509607A

Abstract

The application discloses a filter, which comprises: the magnetic ring comprises a plurality of ferrites, each ferrite is non-closed in the circumferential direction, the plurality of ferrites can be spliced to form a ring-shaped structure which is closed in the circumferential direction, and a wire passing channel is formed among the plurality of ferrites; the shell comprises a plurality of sub-shells, each sub-shell is non-closed in the circumferential direction, a plurality of sub-shells can be spliced to form a ring-shaped structure which is closed in the circumferential direction, the shell is sleeved outside the magnetic ring, each sub-shell comprises a first conductive segment, a second conductive segment and a non-conductive segment connected between the first conductive segment and the second conductive segment, a plurality of the first conductive segments are spliced to form a first conductive ring, a plurality of the second conductive segments are spliced to form a second conductive ring, and a plurality of the non-conductive segments are spliced to form a non-conductive ring. The filter provided by the application can not damage the cable line during installation, and has good anti-interference performance.

Description

Filter

Technical Field

The application relates to the technical field of filters, in particular to a filter.

Background

In modern society, the electromagnetic environment of living and industrial production sites is more and more complex, on-site electric equipment has different working frequency bands, and in order to prevent electromagnetic interference from entering an electric system through a power cable, a filter capable of filtering noise is widely used in various electric equipment.

When the filter in the related art is used, the cable is usually required to be cut off, and then the filter is connected into the cable, so that the cable can be damaged by the installation mode, and the installation operation is very inconvenient.

In order to solve the above problems, a separate EMI filter is proposed, which includes, with reference to fig. 1: the electromagnetic interference (EMI) filter comprises two separation magnets 10 (ferrite), wherein the two separation magnets 10 form a magnetic ring, an openable rubber shell 20 is arranged on the outer side of the two separation magnets 10, elliptical openings 30 are arranged at two ends of the rubber shell 20, and the EMI filter is buckled on a cable line when in use.

The type of filter has the advantages that although the cable is not required to be cut off and the installation is convenient, distributed capacitance exists between the leads, the capacitance resistance is small at high frequency, the high-frequency interference is directly coupled, and the magnetic ring is disabled; in addition, when the high-frequency interference energy is higher, the hysteresis loss and the eddy current loss in the magnetic ring are too large, so that the temperature of the magnetic ring can be quickly increased, because the Curie point (the temperature of the magnetic material losing ferromagnetism) of the ferrite material is lower, once the temperature is too high to reach or exceed the Curie point, the ferrite material can lose magnetism immediately, and the magnetic ring can also lose function. Namely, the separated EMI filter has poor anti-interference performance although the cable is not required to be cut off and the installation is convenient.

Disclosure of Invention

The present application aims to solve at least one of the technical problems existing in the prior art. Therefore, an object of the present application is to provide a filter which does not damage a cable line at the time of installation and has good interference resistance.

According to one embodiment of the application, it comprises: the magnetic ring comprises a plurality of ferrites, each ferrite is non-closed in the circumferential direction, the plurality of ferrites can be spliced to form a ring-shaped structure which is closed in the circumferential direction, and a wire passing channel is formed among the plurality of ferrites; the shell comprises a plurality of sub-shells, each sub-shell is non-closed in the circumferential direction, a plurality of sub-shells can be spliced to form a ring-shaped structure which is closed in the circumferential direction, the shell is sleeved outside the magnetic ring, each sub-shell comprises a first conductive segment, a second conductive segment and a non-conductive segment connected between the first conductive segment and the second conductive segment, a plurality of the first conductive segments are spliced to form a first conductive ring, a plurality of the second conductive segments are spliced to form a second conductive ring, and a plurality of the non-conductive segments are spliced to form a non-conductive ring.

According to the filter provided by the embodiment of the application, a cable is not damaged during installation, and meanwhile, the consumption (the resistance characteristic of the ferrite magnetic ring), reflection (the inductance characteristic of the ferrite magnetic ring) and discharge (two distributed capacitors) of interference noise can be realized, so that the interference resistance is good.

In addition, the filter according to the embodiment of the present application may have the following additional technical features:

according to one embodiment of the application, the ferrite and the sub-housing each form an arc shape.

According to one embodiment of the application, a plurality of the ferrites are connected to a plurality of the sub-housings in a one-to-one correspondence.

According to one embodiment of the application, the two axial ends of the sub-shell are respectively provided with an axial positioning piece, and the two axial positioning pieces are respectively abutted with the two axial end surfaces of the ferrite.

According to one embodiment of the application, the two circumferential locating pieces are respectively arranged at the two circumferential ends of the sub-shell, and the two circumferential locating pieces are respectively abutted with the two circumferential end surfaces of the ferrite.

According to one embodiment of the application, the peripheral end face of the sub-housing is flush with the peripheral end face of the ferrite, the peripheral positioning member extends from the peripheral end face of the sub-housing toward the ferrite, a receiving groove is formed in the peripheral end face of the ferrite, and the peripheral positioning member is received in the receiving groove so that the peripheral positioning member is flush with the peripheral end face of the ferrite.

According to one embodiment of the application, one of the ferrite and the sub-housing is provided with a mating protrusion, and the other of the ferrite and the sub-housing is provided with a mating groove.

According to one embodiment of the application, the mating protrusion or the mating recess is provided on the non-conductive segment.

According to one embodiment of the application, a first conductive fastener is sleeved on the first conductive ring to fasten a plurality of the first conductive segments, and a second conductive fastener is sleeved on the second conductive ring to fasten a plurality of the second conductive segments.

According to one embodiment of the application, the first conductive fastener and the second conductive fastener are conductive nuts, and threads matched with the conductive nuts are arranged on the peripheral walls of the first conductive ring and the second conductive ring.

According to one embodiment of the application, an annular conductive convex disc is arranged on the peripheral wall of the first conductive ring, when the filter is arranged on the conductive mounting base body in a penetrating mode, the conductive convex disc abuts against one side of the conductive mounting base body, and the second conductive fastener abuts against the other side of the conductive mounting base body.

According to one embodiment of the application, the number of the ferrite and the number of the sub-shells are two.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Drawings

The foregoing and/or additional aspects and advantages of the application will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

fig. 1 is a schematic diagram of a prior art split EMI filter;

FIG. 2 is a schematic view of a filter mounted on a conductive mounting base (part of the housing of an electrical cabinet) according to one embodiment of the application;

FIG. 3 is a schematic view of another angle of the structure shown in FIG. 2;

FIG. 4 is a half cross-sectional view of the structure shown in FIG. 2;

FIG. 5 is a schematic view of another angle of the structure shown in FIG. 4;

fig. 6 is a schematic structural view of a sub-housing of the filter shown in fig. 2;

FIG. 7 is a schematic view of another angle configuration of the sub-housing shown in FIG. 6;

FIG. 8 is a schematic view of a further angle of the sub-housing shown in FIG. 6;

FIG. 9 is a half cross-sectional view of the sub-housing shown in FIG. 6;

FIG. 10 is a schematic view of another angle of the structure shown in FIG. 9;

FIG. 11 is a schematic structural view of the ferrite of the filter shown in FIG. 2;

FIG. 12 is a schematic view of another angle of the ferrite shown in FIG. 11;

FIG. 13 is a schematic view of yet another angle of the ferrite shown in FIG. 11;

fig. 14 is a schematic structural view of a conductive nut of a filter according to an embodiment of the present application;

FIG. 15 is a semi-sectional view of a filter according to another embodiment of the application;

FIG. 16 is a schematic view of another angle of the structure shown in FIG. 15;

FIG. 17 is a schematic view of a sub-housing of the filter shown in FIG. 15;

FIG. 18 is a schematic view of another angle of the sub-housing shown in FIG. 17;

fig. 19 is a schematic structural view of a ferrite of the filter shown in fig. 15;

FIG. 20 is a schematic view of another angle of the ferrite shown in FIG. 19;

fig. 21 is a graph comparing insertion loss of a filter according to an embodiment of the present application with insertion loss of a separate EMI filter in the related art.

Reference numerals:

a filter 100;

a magnetic ring 1; ferrite 11; a wire passage 111;

a housing 2; a sub-housing 21; a first conductive segment 211; a second conductive segment 212; a non-conductive segment 213;

an axial positioning member 101; a circumferential positioning member 102; a receiving groove 103; mating projections 104; a fitting groove 105; a conductive nut 106; a conductive cam 107; a first conductive ring 2111; a second conductive ring 2121; a non-conductive ring 2131;

a conductive mounting base 200;

a cable 300; a conductor core 301; a wire insulation layer 302.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application.

The present application has been made based on the knowledge of the applicant that:

To this end, the present application proposes a filter 100 that does not destroy the cable 300 during installation, and that can realize the consumption of interference noise (the resistance characteristic of the ferrite 11 magnetic ring 1), reflection (the inductance characteristic of the ferrite 11 magnetic ring 1), and discharge (two distributed capacitances), and that has good anti-interference performance.

A filter 100 according to an embodiment of the present application is described below with reference to fig. 2-21.

Referring to fig. 2 to 20, a filter 100 according to an embodiment of the present application includes: a magnetic ring 1 and a housing 2.

The magnetic ring 1 includes a plurality of ferrites 11, each ferrite 11 is non-closed in the circumferential direction, the plurality of ferrites 11 can be spliced (spliced end to end in the circumferential direction) to form a ring structure closed in the circumferential direction, and a wire passing channel 111 is formed between the plurality of ferrites 11.

The housing 2 includes a plurality of sub-housings 21, each sub-housing 21 is non-closed in the circumferential direction, the plurality of sub-housings 21 may be spliced (spliced in turn from beginning to end in the circumferential direction) to form a ring structure that is closed in the circumferential direction, the housing 2 is sleeved outside the magnetic ring 1, each sub-housing 21 includes a first conductive section 211, a second conductive section 212, and a non-conductive section 213 connected between the first conductive section 211 and the second conductive section 212, the plurality of first conductive sections 211 are spliced to form a first conductive ring 2111, the plurality of second conductive sections 212 are spliced to form a second conductive ring 2121, and the plurality of non-conductive sections 213 are spliced to form a non-conductive ring 2131.

In the description of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise. I.e. the magnetic ring 1 comprises two (as shown in fig. 2-20) or more ferrites 11 and the housing 2 comprises two (as shown in fig. 2-20) or more sub-housings 21.

In practical application, the cable 300 is not required to be cut off, and the ferrite 11 and the sub-housing 21 are assembled around the cable 300, so that the cable 300 is positioned in the wire passing channel 111, thereby realizing the installation of the filter 100. The filter 100 of the present application is a non-invasive filter 100 that does not destroy the power line signal lines during installation.

The manner of assembling the ferrite 11 and the sub-housing 21 may be arbitrarily selected, for example:

when the filter 100 is installed, a plurality of ferrites 11 can be firstly assembled around the cable 300 in sequence from head to tail in the circumferential direction to form an annular magnetic ring 1, and the assembled cable 300 is positioned in the wire passing channel 111; then, a plurality of sub-shells 21 are assembled in turn from beginning to end in the circumferential direction on the outer side of the magnetic ring 1 to form an annular shell 2 sleeved on the outer circumferential wall of the magnetic ring 1, and when the ferrite is assembled, the connection mode between two adjacent ferrites 11 can be arbitrarily selected, for example, the ferrite can be connected in a clamping or inserting mode, or can also be connected through a connecting piece (such as a bolt and the like), the connection mode between two adjacent sub-shells 21 can also be arbitrarily selected, for example, the ferrite can be connected in a clamping or inserting mode, or can also be connected through a connecting piece (such as a bolt and the like);

alternatively, the ferrites 11 are first connected to the sub-housings 21 in a one-to-one correspondence manner, that is, one ferrite 11 and one sub-housing 21 are correspondingly connected to form one assembly unit, and then the plurality of assembly units are assembled end to end around the cable 300, where the connection manner between two adjacent assembly units may be arbitrarily selected, for example, may be connected by a snap-fit or plug-in manner, or may also be connected by a connection member (for example, the conductive nut 106 described in the following embodiments).

The non-conductive ring 2131 separates the first conductive ring 2111 and the second conductive ring 2121, both of which are grounded, and when the filter 100 is mounted on the cable 300, as shown in fig. 2-5 and 15-16, the cable 300 forms a distributed capacitance with the first conductive ring 2111, the cable 300 forms a distributed capacitance with the second conductive ring 2121, and the magnetic ring 1 forms an inductor, such that the filter 100 forms a pi-type filter 100. I.e. two distributed capacitances are formed between the cable 300 and the housing 2, which together with the magnetic loop 1 constitute the pi-filter 100. This allows the filter 100 of the present application to realize the consumption of interference noise (resistance characteristic of the ferrite bead 11, 1), reflection (inductance characteristic of the ferrite bead 11, 1), and bleed-off (two distributed capacitances). The filter 100 of the application can convert interference noise on the magnetic ring 1 into heat to release, and can also form the pi-type filter 100 by distributing capacitance together with the magnetic ring 1 to release the interference to the shell 2 and finally to the ground.

According to the filter 100 of the embodiment of the application, the cable 300 is not damaged during installation, and meanwhile, the consumption (the resistance characteristic of the ferrite 11 magnetic ring 1), reflection (the inductance characteristic of the ferrite 11 magnetic ring 1) and discharge (two distributed capacitances) of interference noise can be realized, so that the anti-interference performance is good.

The first conductive segment 211 and the second conductive segment 212 each have a conductive characteristic, and preferably, the first conductive segment 211 and the second conductive segment 212 each have a high conductivity. The materials of the first conductive segment 211 and the second conductive segment 212 may be carbon materials, metal materials (iron, gold, silver, cobalt, nickel, aluminum, molybdenum, etc.), alloys thereof, noble metal oxides, conductive polymers, or a mixture of these materials, or a mixture of conductive materials and non-conductive materials. The first conductive segment 211 and the second conductive segment 212 may be made of the same material or different materials.

In addition, the first conductive section 211 and the second conductive section 212 can be made of conductive materials with good thermal conductivity, so that heat generated by the magnetic ring 1 can be quickly released, the temperature rise rate is better reduced, and the risk of loss of magnetism due to the fact that the temperature of the ferrite 11 exceeds the curie point is reduced to a certain extent.

The ferrite 11 may be a ferrite 11 of high magnetic permeability such as Mn-Zn series ferrite 11, niCuZn series ferrite 11, or Mg-Zn series ferrite 11.

In one embodiment of the present application, as shown in fig. 2 to 4, the number of ferrite 11 and sub-housings 21 is two, that is, the number of ferrite 11 is two, and the number of sub-housings 21 is also two, thereby facilitating assembly.

Preferably, as shown in fig. 2 to 4, the two ferrites 11 are identical in structure, the two sub-housings 21 are identical in structure, specifically, the two ferrites 11 are identical in shape, and the two ferrites 11 are identical in size, and the two sub-housings 21 are identical in shape, and the two sub-housings 21 are identical in size, thereby making the filter 100 symmetrical in structure, attractive in appearance, and convenient to manufacture.

In an alternative embodiment of the present application, both the ferrite 11 and the sub-housing 21 are formed in an arc shape, i.e. the ferrite 11 is formed in an arc shape, and the sub-housing 21 is also formed in an arc shape, for example, in the specific example shown in fig. 2 to 20, the ferrite 11 is formed in a semicircular arc shape, and the sub-housing 21 is also formed in a semicircular arc shape, thereby making the filter 100 attractive in structure and convenient to manufacture and assemble. Of course, the present application is not limited thereto, and the shapes of the ferrite 11 and the sub-housing 21 may be arbitrarily selected, for example, the ferrite 11 and the sub-housing 21 may be each formed in a semi-elliptical arc shape.

In one embodiment of the present application, the plurality of ferrites 11 and the plurality of sub-housings 21 are connected in a one-to-one correspondence, that is, one ferrite 11 is correspondingly connected to one sub-housing 21 to form one assembly unit, and then the plurality of assembly units are spliced in turn from end to end in the circumferential direction. As shown in fig. 4 to 10 and fig. 15 to 18, for example, the two ferrites 11 and the two sub-housings 21 are connected one to form two assembly units, which are then assembled together.

The connection manner between the ferrite 11 and the sub-housing 21 may be arbitrarily selected according to needs, for example, optionally, as shown in fig. 2-5 and fig. 15-16, two axial positioning members 101 are respectively disposed at two axial ends of the sub-housing 21, two axial positioning members 101 are respectively abutted with two axial end surfaces of the ferrite 11, the ferrite 11 is positioned between the two axial positioning members 101, and axial positioning of the ferrite 11 is achieved, so that connection between the ferrite 11 and the sub-housing 21 is achieved. The axial positioning member 101 may be a non-conductive elastic member, for example, a plastic member or a rubber member.

Alternatively, as shown in fig. 7 to 10, the two circumferential direction ends of the sub-housing 21 are respectively provided with the circumferential direction positioning pieces 102, the two circumferential direction positioning pieces 102 are respectively abutted with the two circumferential direction end faces of the ferrite 11, the ferrite 11 is positioned between the two circumferential direction positioning pieces 102, the circumferential direction positioning of the ferrite 11 is achieved, and the connection between the ferrite 11 and the sub-housing 21 is achieved. The circumferential positioning member 102 may be a non-conductive elastic member, for example, a plastic member or a rubber member.

Further, as shown in fig. 7 to 12, the circumferential end face of the sub-housing 21 is flush with the circumferential end face of the ferrite 11, the circumferential positioning piece 102 extends from the circumferential end face of the sub-housing 21 toward the ferrite 11, the circumferential end face of the ferrite 11 is formed with a receiving groove 103, and the circumferential positioning piece 102 is received in the receiving groove 103 so that the circumferential positioning piece 102 is flush with the circumferential end face of the ferrite 11. When ferrite 11 is positioned between two circumference setting element 102, circumference setting element 102 holding is in holding groove 103, can avoid circumference setting element 102 protrusion in ferrite 11's circumference terminal surface, when two assembly units assemble like this, two assembly units can dock better, and two ferrite 11's circumference terminal surface can fully laminate together, and two sub-shell 21's circumference terminal surface can fully laminate together, can not form the clearance in the concatenation department, guarantees the interference immunity of filter 100 from this.

Alternatively, one of the ferrite 11 and the sub-housing 21 is provided with a fitting protrusion 104, and the other of the ferrite 11 and the sub-housing 21 is provided with a fitting groove 105. Here, two specific examples are included, in one example, as shown in fig. 4 to 13, the ferrite 11 is provided with a fitting protrusion 104, and the sub-housing 21 is provided with a fitting groove 105; in another example, the ferrite 11 is provided with a mating groove 105 and the sub-housing 21 is provided with a mating protrusion 104. The connection between the ferrite 11 and the sub-housing 21 is made more stable and reliable by the engagement between the engagement protrusion 104 and the engagement recess 105. As shown in fig. 4 to 13, the fitting protrusion 104 and the fitting groove 105 may extend in the circumferential direction of the filter 100; of course, the fitting projection 104 and the fitting recess 105 may also extend in the axial direction of the filter 100 (not shown).

Further, the fitting projection 104 or the fitting recess 105 is provided on the non-conductive section 213. As shown, for example, in fig. 7-10, mating grooves 105 are formed on non-conductive segments 213. By forming the mating recess 105 on the non-conductive segment 213, the filter 100 structure is more stacked, facilitating manufacturing. Of course, the present application is not limited thereto, and the fitting protrusion 104 or the fitting groove 105 may be formed on the first conductive section 211 or the second conductive section 212.

Of course, the connection positioning manner between the ferrite 11 and the sub-housing 21 is not limited to the axial positioning member 101 and the circumferential positioning member 102, and the fitting protrusion 104 and the fitting groove 105, and the ferrite 11 and the sub-housing 21 may be connected by a connection member such as a bonding member or a bolt.

The connection mode between two adjacent assembly units can also be selected optionally according to the needs, for example, the first conductive ring 2111 is sleeved with a first conductive fastener to fasten the plurality of first conductive segments 211, the second conductive ring 2121 is sleeved with a second conductive fastener to fasten the plurality of second conductive segments 212, so that the connection between two adjacent assembly units is realized, and the connection is convenient and the connection reliability is high. And the first conductive fastener and the second conductive fastener are conductive members, so that the contact area between the plurality of first conductive segments 211 and the contact area between the plurality of second conductive segments 212 can be increased, and the anti-interference performance of the filter 100 can be improved.

The first conductive fastener and the second conductive fastener each have conductive characteristics, preferably, the first conductive fastener and the second conductive fastener each have high electrical conductivity. The materials of the first conductive fastener and the second conductive fastener can be carbon materials, metal materials (iron, gold, silver, cobalt, nickel, aluminum, molybdenum and the like), alloys thereof, noble metal oxides, conductive polymers, mixed materials of the materials, and mixed materials of conductive materials and non-conductive materials. The first conductive fastener and the second conductive fastener may be made of the same material or may be made of different materials.

Alternatively, as shown in fig. 14, the first conductive fastener and the second conductive fastener are conductive nuts 106, threads matching with the conductive nuts 106 are provided on the outer peripheral walls of the first conductive ring 2111 and the second conductive ring 2121, the first conductive fastener is screwed on the outer peripheral wall of the first conductive ring 2111, and the second conductive fastener is screwed on the outer peripheral wall of the second conductive ring 2121. By means of the threaded engagement, the first conductive fastener is securely engaged to the first conductive ring 2111 and the second conductive fastener is securely engaged to the second conductive ring 2121.

Further, as shown in fig. 2 to 10, an annular conductive boss 107 is provided on the outer peripheral wall of the first conductive ring 2111, and when the filter 100 is installed on the conductive mounting base 200 (i.e., the ground), the conductive boss 107 abuts against one side of the conductive mounting base 200, and the second conductive fastener abuts against the other side of the conductive mounting base 200, thereby mounting the filter 100 on the conductive mounting base 200. In addition, the first conductive ring 2111 is connected to the ground by the conductive cam 107 abutting the conductive mounting base 200, the second conductive fastener is fitted on the second conductive ring 2121 and the second conductive fastener abuts the conductive mounting base 200 (the axial length of the second conductive fastener is longer than the axial length of the non-conductive ring 2131), and the second conductive ring 2121 is connected to the ground by the second conductive fastener. The conductive mounting substrate 200 may be a conductive housing (e.g., a metal housing, etc.) of an electrical cabinet.

The conductive mounting base 200 is provided with a mounting hole having a diameter slightly larger than a diameter of a thread on the outer circumferential wall of the filter 100, thereby facilitating the insertion of the filter 100 into the mounting hole.

As shown in fig. 4 to 5 and fig. 15 to 16, the cable 300 includes a conductor core 301 and a conductor insulating layer 302 covering the conductor core 301, and when the filter 100 is mounted on the cable 300, the outer diameter of the conductor core 301 is 2R, and the inner diameters of the first conductive ring 2111 and the second conductive ring 2121 are 2R. According to the calculation formula of the coaxial cylindrical capacitor:

the capacitance values of the two distributed capacitances of the filter 100 can be estimated, where C is the capacitance, L is the cylindrical capacitor length, R is the cylindrical capacitor outer cylinder radius, R is the cylindrical capacitor inner cylinder radius (i.e., the outer radius of the conductive core 301), and ε is the equivalent dielectric constant.

In estimating the capacitance value of the distributed capacitance formed by the cable 300 and the first conductive ring 2111, L is the axial length of the first conductive ring 2111, and R is the inner radius of the first conductive ring 2111; in estimating the capacitance of the distributed capacitance formed by cable 300 and second conductive ring 2121, L is the axial length of second conductive ring 2121 and R is the inner radius of second conductive ring 2121.

By adjusting the material types of the ferrite 11, the axial lengths of the first conductive ring 2111 and the second conductive ring 2121, the outer diameter of the wire core 301, the inner diameters of the first conductive ring 2111 and the second conductive ring 2121, and the distance between the outer diameter edge of the wire core 301 and the inner diameter edges of the first conductive ring 2111 and the second conductive ring 2121, the capacitance value of the distributed capacitance is adjusted. The equivalent capacitance value is estimated to be 1 pF-1 nF.

The two distributed capacitances of the filter 100 and the magnetic ring 1 form a pi-type filter 100, and the pi-type filter 100 is of a C-L-C type and a C-R-C type simultaneously because the magnetic ring 1 has inductance and resistance characteristics. The advantages of the pi-type filter 100 formed by the two distributed capacitors and the magnetic ring 1 are illustrated by taking the example that the equivalent capacitance values of the two distributed capacitors are 1nF and 0.1nF respectively, the characteristic parameters of the magnetic ring 1 are 25MHz, 100MHz and 1GHz respectively, the equivalent resistances of the magnetic ring 1 are 130 Ω, 250 Ω and 50 Ω respectively, and the equivalent inductances of the magnetic ring 1 are 3.2nH, 0.06nH and 0nH respectively. As shown in fig. 21, it can be seen that the pi-type filter 100 of the present application, which is composed of two distributed capacitors and the magnetic loop 1, can significantly improve the insertion loss thereof compared to the EMI filter 100 of the prior art, which is composed of a single magnetic loop 1.

In the description of the present application, it should be understood that the directions or positional relationships indicated by the terms "center", "inner", "outer", "axial", "circumferential", etc., are based on the directions or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application.

In the description of the application, a feature of "a first XXX", "a second XXX" may explicitly or implicitly include one or more corresponding features.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the description of the present application, unless explicitly specified and limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, and may also include both the first and second features not being in direct contact but being in contact with each other by way of additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the application, the scope of which is defined by the claims and their equivalents.

Claims

1. A filter, comprising:

the magnetic ring comprises a plurality of ferrites, each ferrite is non-closed in the circumferential direction, the plurality of ferrites can be spliced to form a ring-shaped structure which is closed in the circumferential direction, and a wire passing channel is formed among the plurality of ferrites;

the shell comprises a plurality of sub-shells, each sub-shell is non-closed in the circumferential direction, a plurality of sub-shells can be spliced to form a ring-shaped structure which is closed in the circumferential direction, the shell is sleeved outside the magnetic ring, each sub-shell comprises a first conductive segment, a second conductive segment and a non-conductive segment connected between the first conductive segment and the second conductive segment, a plurality of the first conductive segments are spliced to form a first conductive ring, a plurality of the second conductive segments are spliced to form a second conductive ring, and a plurality of the non-conductive segments are spliced to form a non-conductive ring.

2. The filter of claim 1, wherein the ferrite and the sub-housing each form an arc shape.

3. The filter of claim 1, wherein a plurality of said ferrites are connected to a plurality of said sub-housings in a one-to-one correspondence.

4. A filter according to claim 3, wherein axial positioning members are respectively provided at both axial ends of the sub-housing, and both of the axial positioning members are respectively abutted against both axial end surfaces of the ferrite.

5. A filter according to claim 3, wherein the sub-housing is provided with circumferential positioning members at both circumferential ends thereof, respectively, and the two circumferential positioning members are abutted with both circumferential end surfaces of the ferrite, respectively.

6. The filter of claim 5, wherein the peripheral end face of the sub-housing is flush with the peripheral end face of the ferrite, the peripheral locating member extends from the peripheral end face of the sub-housing toward the ferrite, a receiving groove is formed in the peripheral end face of the ferrite, and the peripheral locating member is received in the receiving groove so that the peripheral locating member is flush with the peripheral end face of the ferrite.

7. A filter according to claim 3, wherein one of the ferrite and the sub-housing is provided with a mating protrusion and the other of the ferrite and the sub-housing is provided with a mating recess.

8. The filter of claim 7, wherein the mating protrusion or the mating groove is provided on the non-conductive segment.

9. The filter of claim 1, wherein a first conductive fastener is sleeved on the first conductive ring to secure a plurality of the first conductive segments, and a second conductive fastener is sleeved on the second conductive ring to secure a plurality of the second conductive segments.

10. The filter of claim 9, wherein the first and second conductive fasteners are conductive nuts, and the outer peripheral walls of the first and second conductive rings are each provided with threads that mate with the conductive nuts.

11. The filter of claim 10, wherein the first conductive ring has an annular conductive collar disposed on an outer peripheral wall thereof, the conductive collar abutting one side of the conductive mounting substrate when the filter is threaded onto the conductive mounting substrate, and the second conductive fastener abutting the other side of the conductive mounting substrate.

12. The filter of any of claims 1-11, wherein the number of ferrite and the number of sub-housings are two.