CN204157216U - Electromagnetic interference filter - Google Patents

Abstract

The electromagnetic interference filter provided by the utility model includes a cover body, at least two inductors of different frequencies connected to each other, a first capacitor, a second capacitor, an input terminal and an output terminal. The current increasing structure of the current of the device; at least two inductors and the second capacitor are respectively arranged at the two ends inside the cover body; the input terminal and the output terminal are respectively arranged on the two outer sides of the cover body. Since the current increasing structure is provided in the cover body, the current flowing through the internal parts of the cover body is greater than the current of the cover body structure in the prior art by means of the current increasing structure, so as to reduce the DC resistance of the electromagnetic interference filter, thereby Reduce the power consumption of the electromagnetic interference filter; at the same time, since at least two inductors of different frequencies connected to each other are provided to suppress different frequency bands, compared with the prior art single inductor arrangement structure, the bandwidth can be effectively made From 100KHz-1GHz to 100KHz-2GHz.

Description

EMI filter

technical field

The utility model relates to the technical field of filters, in particular to an electromagnetic interference filter.

Background technique

Electromagnetic interference (EMI) filter is a low-pass filter composed of inductors and capacitors, which allows low-frequency useful signals to pass smoothly, while suppressing high-frequency interference.

The electromagnetic interference filter is mainly composed of a cover body, and inductors and capacitors installed inside the cover body. Among them, the current cover body structure is mostly injection-molded, and then no further processing is performed. This type of cover body structure is used in When the current flows through the internal parts of the cover, a large DC resistance will be generated, which will not only cause a large power consumption of the EMI filter, but also easily cause the cover to heat up and reduce the reliability of the EMI filter; , since most current EMI filters are only provided with a single inductor, and it is difficult for a single inductor to suppress different frequency bands.

Therefore, it is necessary to provide a technical means to solve the above defects.

Utility model content

The purpose of the utility model is to overcome the defects of the prior art. The electromagnetic interference filter provided can solve the problem that the structure of the electromagnetic interference filter of the prior art is easy to generate a large DC resistance due to the current flowing through the internal parts of the cover. As a result, the electromagnetic interference filter produces a relatively large power consumption, and the cover easily heats up and generates heat, and solves the problem that the electromagnetic interference filter in the prior art is difficult to suppress different frequency bands.

The utility model is achieved in that the electromagnetic interference filter comprises:

A cover body, the cover body has a first outer side and a second outer side disposed relative to the first outer side, the cover body has at least a first end and a second end disposed relative to the first end, and the cover body The body is also provided with a current increasing structure that can increase the current of the electromagnetic interference filter;

At least two inductors with different frequencies are located at the first end and each of the inductors is connected to each other;

a first capacitor disposed inside the cover and in contact with at least two of the inductors;

a second capacitor disposed at the second end and adjacent to at least two of the inductors;

an input terminal pierced through the first outer side and connected to at least two of the inductors; and

The output terminal passes through the second outer side and is connected to the second capacitor.

Specifically, the current increasing structure is a conductive metal layer attached to the inner wall of the cover, and at least two of the inductors are connected to the conductive metal layer through coils arranged inside.

Specifically, there are three inductors.

Further, any one of the inductors includes an inductance core, and the inductance core has an elliptical structure.

Specifically, the first capacitor has a chip structure.

Specifically, the second capacitor is a feedthrough capacitor.

Further, the feedthrough capacitor has a square structure.

Further, a bandwidth suppression structure capable of suppressing the bandwidth of the electromagnetic interference filter is provided outside the feedthrough capacitor.

Preferably, the bandwidth suppression structure is a lead-tin layer plated on the outside of the feedthrough capacitor.

Specifically, the cover body includes an upper cover and a lower cover, hooks are provided on both sides of the upper cover, and slots corresponding to the hooks are provided on both sides of the lower cover. The cover is engaged with the lower cover through the clamping of the hook and the slot.

The technical effect of the electromagnetic interference filter of the utility model is: since the cover body of the utility model is provided with a current increasing structure, by means of the current increasing structure, the current flowing through the internal parts of the cover body is greater than that of the cover of the prior art The current of the body structure is used to reduce the DC resistance of the EMI filter, thereby reducing the power consumption of the EMI filter; at the same time, since the utility model is provided with at least two inductors of different frequencies connected to each other, to suppress different The frequency band, compared with the prior art single inductor structure, can effectively make the bandwidth from 100KHz-1GHz to 100KHz-2GHz.

Description of drawings

Fig. 1 is the schematic diagram of the electromagnetic interference filter of the utility model embodiment;

Fig. 2 is the schematic diagram of another angle of the electromagnetic interference filter of the utility model embodiment;

Fig. 3 is a sectional view of A-A direction in Fig. 2;

Fig. 4 is an exploded view of the electromagnetic interference filter of the embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

Referring to Fig. 1 to Fig. 4, the following describes the best embodiment of the electromagnetic interference filter of the present invention.

The electromagnetic interference filter 100 of the present embodiment includes a cover body 10, at least two inductors 20 of different frequencies connected to each other, a first capacitor 30, a second capacitor 40, an input terminal 50 and an output terminal 60, facing the electromagnetic Each part of interference filter 100 is described further:

The cover body 10 has a first outer side and a second outer side arranged relative to the first outer side, the cover body 10 has at least a first end and a second end arranged relative to the first end, and the cover body 10 is also provided with There is a current increasing structure 11 that can increase the current of the electromagnetic interference filter 100. In addition, the height of the cover body 10 is 4mm, and an installation cavity is provided in the cover body 10, and the installation space of the installation cavity is 2.0-2.5mm ;

The at least two inductors 20 with different frequencies are arranged at the first end of the cover 10 and each inductor 20 is connected to each other;

The first capacitor 30 is disposed inside the cover 10 and is in contact with at least two inductors 20;

The second capacitor 40 is disposed at the second end of the cover 10 and adjacent to at least two inductors 20 ;

The input terminal 50 is disposed on the first outer side of the cover 10 and connected to at least two inductors 20 ;

The output terminal 60 is disposed on a second outer side relative to the first outer side of the cover 10 and connected to the second capacitor 40 .

Since the current increasing structure 11 is provided in the cover body 10 of this embodiment, the current flowing through the internal components of the cover body 10 is greater than the current of the cover body structure in the prior art by means of the current increasing structure 11, thereby reducing The DC resistance of the electromagnetic interference filter 100, thereby reducing the power consumption of the electromagnetic interference filter 100; meanwhile, since the present embodiment is provided with at least two inductors 20 of different frequencies connected to each other, to suppress different frequency bands, compared with the existing The technical single inductor setting structure can effectively make the bandwidth from 100KHz-1GHz to 100KHz-2GHz.

Please refer to FIG. 3. Specifically, the current increasing structure 11 is a conductive metal layer attached to the inner wall of the cover body 10. Preferably, as long as at least one of the inner walls of the cover body 10 is attached with a conductive metal layer, the current flow The current conduction of the internal components of the cover body 10 is unimpeded, reducing the DC resistance of the electromagnetic interference filter 100, thereby increasing the current of the electromagnetic interference filter 100; The coils of the inductors 20 are connected to the conductive metal layer, so that the at least two inductors 20 do not need to be additionally equipped with conductively connected coils, as long as the coils arranged inside the at least two inductors 20 are connected to the conductive metal layer, Hereby, the heat generation of the EMI filter 100 can be minimized.

Please refer to FIG. 4 , there are three inductors 20 in this embodiment, of course, more than three inductors can also be provided according to actual needs. Wherein, any inductor 20 includes an inductance magnetic core 21, and in order to make the size of the inductor 20 smaller and more suitable for installation in the installation cavity of the cover body 10, the inductance magnetic core 21 is an oval structure with a height of 1.9 mm.

Preferably, the first capacitor 30 in this embodiment has a chip structure, that is, the first capacitor 30 is a chip capacitor, and the chip capacitor has the characteristics of large capacity, small volume, and easy chip formation. In order to facilitate the acquisition of materials, the chip capacitor is a chip multilayer ceramic dielectric capacitor. Among them, a chip multilayer ceramic capacitor (MLCC), referred to as a chip multilayer capacitor (or further referred to as a chip capacitor), is made of printed The ceramic dielectric diaphragms of the electrode (internal electrode) are stacked in a dislocation manner, and a ceramic chip is formed by one-time high-temperature sintering, and then a metal layer (external electrode) is sealed on both ends of the chip to form a monolithic structure. body, so it is also called a monolithic capacitor. The main components of commonly used ceramic media are MgTiO3, CaTiO3, SrTiO3 and TiO2, and then add appropriate amount of rare earth oxides, etc., which are characterized by large dielectric coefficient, low dielectric loss, small temperature coefficient, and wide application range of ambient temperature. And high-frequency characteristics are good, used in occasions with higher requirements (Class I ceramic capacitors).

Please refer to FIG. 4 again, the second capacitor 40 is a feedthrough capacitor, and the feedthrough capacitor is a filter device mainly used on metal panels to suppress interference of high-frequency harmonics on signals and power lines.

In order to make the size of the feedthrough capacitor smaller and more suitable for installation in the installation cavity of the cover body 10, the feedthrough capacitor has a square structure, that is, the feedthrough capacitor has a square shell, and the height of the square shell is 2.2mm.

What have again is that the outside of the feedthrough capacitor is provided with a bandwidth suppressing structure 41 that can suppress the bandwidth of the electromagnetic interference filter 100, and by this bandwidth suppressing structure 41, the required range of bandwidth suppression is achieved, so as to ensure the bandwidth of the electromagnetic interference filter 100 High frequency and broadband performance, and can further guarantee the bandwidth to reach 100KHz-2GHz. Preferably, the bandwidth suppression structure 41 is a lead-tin layer plated on the outside of the feedthrough capacitor, specifically, the lead-tin layer is plated between the two surfaces of the square shell except for the electrodes of the feedthrough capacitor. other surfaces.

Please continue to refer to FIG. 4 , in order to facilitate the installation of the internal components of the electromagnetic interference filter 100 on the cover 10, the cover 10 of the present embodiment includes an upper cover 12 and a lower cover 13, and hooks are provided on both sides of the upper cover 12 120, the two sides of the lower cover 13 are provided with card slots 13 corresponding to the hooks 12, and the upper cover 12 is engaged with the lower cover 13 through the card hooks 120 and the card slots 130. Specifically, during installation, as long as Install each internal component on the lower cover 13, and then make the hook 120 of the upper cover 12 engage in the slot 130 of the lower cover 13, so that the internal components can be covered and protected, which greatly facilitates the installation of the installer.

In addition, the electromagnetic interference filter 100 also includes a grounding metal sheet disposed inside the cover 10. With the grounding hardware 70, each internal component disposed inside the cover 10 can be grounded to prevent the internal components from being charged. And endanger the personal safety of users.

The above description is only a preferred embodiment of the utility model, and its structure is not limited to the shapes listed above. Any modifications, equivalent replacements and improvements made within the spirit and principles of the utility model should include Within the protection scope of the present utility model.

Claims (10)

1. Electromagnetic interference filter, is characterized in that, comprising:

Lid, to have outside described lid outside first and relative to second of this first arranged outside outside, the second end that at least there is in described lid first end and arrange relative to this first end, and the electric current being also provided with the electric current that can increase described Electromagnetic interference filter in described lid increases structure;

At least two inductors with different frequency, are located at described first end and each described inductor is interconnected;

First electric capacity, is located at described lid portion inside and touches with at least two described inductors;

Second electric capacity, is located at described second end and is adjacent at least two described inductors;

Input terminal, is connected at least two described inductors outside being arranged in described first; And

Lead-out terminal, is connected to described second electric capacity outside being arranged in described second.

2. Electromagnetic interference filter as claimed in claim 1, is characterized in that: it is be attached to the conductive metal layer on described lid inwall that described electric current increases structure, and at least two described inductors are connected with described conductive metal layer by its inner coil arranged.

3. Electromagnetic interference filter as claimed in claim 1, is characterized in that: described inductor is provided with three.

4. Electromagnetic interference filter as claimed in claim 3, it is characterized in that: arbitrary described inductor includes inductance core, and described inductance core is ellipsoidal structure.

5. Electromagnetic interference filter as claimed in claim 1, is characterized in that: described first electric capacity is slice structure.

6. Electromagnetic interference filter as claimed in claim 1, is characterized in that: described second electric capacity is feedthrough capacitor.

7. Electromagnetic interference filter as claimed in claim 6, is characterized in that: described feedthrough capacitor is square structure.

8. Electromagnetic interference filter as claimed in claim 6, is characterized in that: the outside of described feedthrough capacitor is provided with and the bandwidth of described Electromagnetic interference filter bandwidth can be suppressed to suppress structure.

9. Electromagnetic interference filter as claimed in claim 8, is characterized in that: described bandwidth suppresses structure to be plate the slicker solder layer be located on outside described feedthrough capacitor.

10. the Electromagnetic interference filter as described in any one of claim 1-9, it is characterized in that: described lid comprises upper cover and lower cover, the both sides of described upper cover are provided with grab, the both sides of described lower cover are provided with the draw-in groove of clamping corresponding to described grab, and described upper cover is engaged with described lower cover with described draw-in groove clamping by described grab.