Power supply electromagnetic interference filter

Abstract

The utility model belongs to the technical field of filters, and particularly discloses a power supply electromagnetic interference filter which comprises a first differential mode inductor loop, a second differential mode inductor loop and a third differential mode inductor loop, the two output ends of the first differential mode inductor loop are electrically connected with the two input ends of the second differential mode inductor loop respectively, and the two output ends of the third differential mode inductor loop are electrically connected with the first differential mode inductor loop. The two output ends of the second differential mode inductor loop are electrically connected with the two input ends of the third differential mode inductor loop respectively, and the two output ends of the third differential mode inductor loop are connected with the filter inductors in series respectively. According to the utility model, three groups of differential mode inductor loops are designed, three-stage filtering is integrated, the suppression characteristic is excellent, external electromagnetic interference signal conduction and emission of the nuclear magnetic resonance intelligent detection system can be effectively reduced, and electromagnetic interference signal conduction and emission from an external power grid to the nuclear magnetic resonance intelligent detection system can be effectively suppressed.

Description

TECHNICAL FIELD

[0001] The utility model relates to filter technical field, especially a power supply electromagnetic interference filter. BACKGROUND

[0002] The electromagnetic compatibility (EMC) of the nuclear magnetic resonance intelligent detection system is the key to improving the nuclear magnetic resonance intelligent detection imaging effect. The traditional power supply filter has a narrow filtering frequency band and low filtering capacity. As a medical product, the nuclear magnetic resonance intelligent detection system needs to meet the electromagnetic compatibility standards of medical electrical equipment, YY0505-2012 (IEC60601-1-2:2004) Medical Electrical Equipment - Part 1-2: General Requirements for Safety - Collateral Standard: Electromagnetic Compatibility Tests and Requirements, and GB9706.1-1995 Medical Electrical Equipment - Part 1: General Requirements for Safety, and needs to meet the electromagnetic compatibility tests and requirements, so a power supply electromagnetic interference filter needs to be designed to improve the electromagnetic compatibility of the nuclear magnetic resonance intelligent detection system. SUMMARY

[0003] The utility model discloses a power supply electromagnetic interference filter to solve the technical problems in the background art.

[0004] To achieve the above object, the utility model adopts the following technical scheme:

[0005] A power supply electromagnetic interference filter, comprising a first differential mode inductor loop, a second differential mode inductor loop and a third differential mode inductor loop, the output ends of the first differential mode inductor loop are electrically connected to the input ends of the second differential mode inductor loop, the output ends of the second differential mode inductor loop are electrically connected to the input ends of the third differential mode inductor loop, and one filter inductor is connected in series to the output ends of the third differential mode inductor loop.

[0006] The utility model further limits the technical scheme as follows, further comprising filter input ends and filter output ends, the filter input ends are connected to the input ends of the first differential mode inductor loop, and one filter inductor is connected in series to the output ends of the third differential mode inductor loop and connected to the filter output ends.

[0007] The utility model further limits the technical scheme as follows, the first differential mode inductor loop comprises differential mode inductor L D11 , through-hole capacitor C Y11 , C Y12 And differential mode inductor L D12 ;

[0008] The filter input ends are connected to one end of differential mode inductor L D11 and differential mode inductor LD12 one end of the differential mode inductor L

[0009] the other end of the differential mode inductor L D11 is electrically connected with an input end of the through-hole capacitor C Y11 , the other end of the differential mode inductor L D12 is electrically connected with an input end of the through-hole capacitor C Y12 , a ground end of the through-hole capacitor C Y11 is electrically connected with a ground end of the through-hole capacitor C Y12 ;

[0010] the output end of the through-hole capacitor C Y11 and the output end of the through-hole capacitor C Y12 are respectively electrically connected with two ends of an input of the second differential mode inductor loop.

[0011] The second differential mode inductor loop comprises a differential mode inductor L D21 , a capacitor C Y21 , C Y22 and a differential mode inductor L D22 .

[0012] two ends of an output of the first differential mode inductor loop are respectively connected with one end of the differential mode inductor L D21 and one end of the differential mode inductor L D22 .

[0013] the other end of the differential mode inductor L D21 is electrically connected with one end of the capacitor C Y21 , the other end of the differential mode inductor L D22 is electrically connected with one end of the capacitor C Y22 , the other end of the capacitor C Y21 is electrically connected with the other end of the capacitor C Y22 ;

[0014] one end of the differential mode inductor L D21 close to the capacitor C Y21 is electrically connected with one end of an input of the third differential mode inductor loop, and one end of the differential mode inductor L D22 close to the capacitor C Y22 is electrically connected with the other end of the input of the third differential mode inductor loop.

[0015] The third differential mode inductor loop comprises a differential mode inductor L D31 , a through-hole capacitor C Y31 , C Y32 and a differential mode inductor L D32 .

[0016] The output ends of the second differential mode inductor loop are connected to one end of a differential mode inductor L D31 and one end of a differential mode inductor L D32 respectively.

[0017] The other end of the differential mode inductor L D31 is electrically connected to an input end of a through-hole capacitor C Y31 , the other end of the differential mode inductor L D32 is electrically connected to an input end of a through-hole capacitor C Y32 , a ground end of the through-hole capacitor C Y31 is electrically connected to a ground end of the through-hole capacitor C Y32 .

[0018] The output end of the through-hole capacitor C Y31 and the output end of the through-hole capacitor C Y32 are respectively connected in series with a filter inductor and are respectively connected to output ends of a filter.

[0019] The utility model further limits the technical scheme, further includes shell subassembly, installs input copper row subassembly and output copper row subassembly respectively on both sides of shell subassembly.

[0020] The utility model further limits the technical scheme, the shell subassembly includes the shroud and the inner frame, and the inner frame is fixedly connected with the shroud through the fastener.

[0021] The utility model further limits the technical scheme, the input copper row subassembly and output copper row subassembly are all constructed by copper row outer sleeve insulating column

[0022] Compared with the prior art, the utility model has the following technical effects:

[0023] The utility model discloses three differential mode inductor loops, three-stage filtering is integrated, the inhibition characteristic is excellent, can effectively reduce the nuclear magnetic resonance intelligent detection system to the outside electromagnetic interference signal conduction emission, also can effectively inhibit the electromagnetic interference signal conduction emission from the external power grid to the nuclear magnetic resonance intelligent detection system, through the bolt end cover wall -penetrating installation design, can install the top or bottom outside of nuclear magnetic resonance intelligent detection system shielding room, carries out the isolation to the internal and external complex electromagnetic environment of shielding room, has good shielding design, shielding efficiency is high, can effectively improve the nuclear magnetic resonance intelligent detection imaging effect, the setting of inner frame and shroud can effectively protect electronic components, prevent physical abrasion or chemical damage.

[0024] The utility model is further explained in connection with the drawings and examples. DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art. Obviously, the drawings described in the following are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0026] Figure 1 is a circuit connection relationship diagram of the present application;

[0027] Figure 2 is a filter insertion loss curve diagram measured in the 50Ω system of the present application;

[0028] Figure 3 is a front view structural schematic diagram of the present application;

[0029] Figure 4 is a right view structural schematic diagram of the present application;

[0030] Figure 5 is a left view structural schematic diagram of the present application;

[0031] Figure 6 is a top view structural schematic diagram of the present application. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned purposes, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the drawings. In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a variety of ways other than those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0033] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0034] In the description of the utility model, it is necessary to understand that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one feature.

[0035] In the embodiments of the utility model, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the communication or interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the embodiments of the utility model can be understood according to the specific circumstances.

[0036] As shown in Figures 1-6 , the embodiment provides a circuit structure and mechanical structure of power electromagnetic interference filter.

[0037] As shown in Figure 1 , a circuit structure of power electromagnetic interference filter, comprising filter input two ends, filter output two ends, first differential mode inductor loop, second differential mode inductor loop and third differential mode inductor loop. Specifically: the first differential mode inductor loop comprises differential mode inductor L D11 , through-hole capacitor C Y11 , C Y12 And differential mode inductor L D12 ; the second differential mode inductor loop comprises differential mode inductor L D21 , capacitor C Y21 , C Y22 And differential mode inductor L D22 ; the third differential mode inductor loop comprises differential mode inductor L D31 , through-hole capacitor C Y31 , C Y32 And differential mode inductor L D32 .

[0038] The filter input two ends are respectively connected with one end of differential mode inductor L D11 And one end of differential mode inductor L D12 ; the other end of differential mode inductor L D11 With the input end of through-hole capacitor C Y11 Electrically connected, the other end of differential mode inductor L D12 With the input end of through-hole capacitor C Y12 Electrically connected, the ground end of through-hole capacitor C Y11 With the ground end of through-hole capacitor C Y12 Electrically connected;through-hole capacitor C Y11The output terminal and the feedthrough capacitor C Y12 The output terminals are respectively connected to differential mode inductors L D21 One end of the differential mode inductor L D22 One end; differential mode inductor L D21 The other end is connected to capacitor C Y21 One end is electrically connected to the differential mode inductor L. D22 The other end is connected to capacitor C Y22 One end is electrically connected, capacitor C Y21 The other end is connected to capacitor C Y22 The other end is electrically connected; differential mode inductor L D21 Close to capacitor C Y21 One end is connected to the differential mode inductor L D31 One end is electrically connected to the differential mode inductor L. D22 Close to capacitor C Y22 One end is connected to the differential mode inductor L D32 One end is electrically connected; differential mode inductor L D31 The other end is connected to the feedthrough capacitor C Y31 The input terminals are electrically connected, and the differential mode inductor L is... D32 The other end is connected to the feedthrough capacitor C Y32 The input terminal is electrically connected, and the feedthrough capacitor C is... Y31 The grounding terminal and the feedthrough capacitor C Y32 Electrical connection of the grounding terminal; feedthrough capacitor C Y31 The output terminal and the feedthrough capacitor C Y32 Each of the output terminals is connected in series with a filter inductor and then connected to the two ends of the filter output. It should be noted that... Figure 1 The dashed line in the diagram is connected to the grounding terminal.

[0039] Therefore, three sets of differential-mode inductor circuits are used to suppress residual pulse voltage on the power line; feedthrough capacitor C Y11 C Y12 C Y31 C Y32 Used to eliminate high-frequency coupling; the output terminals of the third differential mode inductor circuit are connected in series with filter inductors L. D41 L D42 With the feedthrough capacitor C on the output side Y31 C Y32 Combined, they form a composite filter.

[0040] like Figure 2 The figure shows the insertion loss curve of the power supply electromagnetic interference filter provided in this embodiment within 50Ω: the horizontal axis represents the frequency in MHz, the starting frequency is 1MHz, the ending frequency is 200MHz, and each division is 20MHz; the vertical axis represents the loss value in dB, the starting loss is 0dB, the ending loss is -140dB, and each division is 20dB.

[0041] Therefore, the power electromagnetic interference filter provided by the embodiment has the following specific test values of insertion loss measured within 50Ω: 10MHz / -93.77dB, 50MHz / -118.2dB, 100MHz / -132.8dB, 150MHz / -121.3dB, and 200MHz / -131.1dB. The results show that the filtering of electromagnetic interference signals can be effectively achieved.

[0042] As shown in Figures 3-6 A mechanical structure of a power electromagnetic interference filter is shown in the drawings. The outer side of the filter is provided with a housing assembly for isolating an electromagnetic environment. The housing assembly includes a shroud 201, and the two sides of the shroud 201 are respectively provided with inner frames 101. The inner frames 101 are connected with the shroud 201 through fasteners 202, and the inside of the inner frames 101 and the shroud 201 forms a containing space in which a circuit structure of the power electromagnetic interference filter can be placed. The shroud 201 is provided with a nameplate 203. The inner frames 101 on the two sides of the shroud 201 are respectively provided with an input copper bar 301 and an output copper bar 401. One end of the input copper bar 301 and the output copper bar 401 is arranged on the outside of the inner frame 101, and the other end penetrates through the inner frame 101 and is connected with the input end and the output end of the filter, respectively. Figure 3 As shown in the drawings, the input copper bar 301 is installed on the right side of the inner frame 101 and reaches the input external space of the containing space, and the output copper bar 401 is installed on the left side of the inner frame 101 and reaches the output external space of the containing space. The input copper bar 301 is provided with an insulating column 402 from the outside to the inside; and the output copper bar 401 is provided with insulating columns 402 from the outside to the inside in sequence.

[0043] The input copper bar 301 of the filter adopts a bolt end cover through-wall mounting design, which can be installed on the outside of the top or bottom of a nuclear magnetic resonance intelligent detection system shielding room, and can isolate the complex electromagnetic environment inside and outside the shielding room, thereby having a good shielding design.

[0044] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present application, or modify it into equivalent embodiments, without departing from the scope of the technical solution of the present application, by using the disclosed methods and technical contents. Therefore, any equivalent changes made according to the shape, structure and principle of the present application, without departing from the technical solution of the present application, should be covered by the protection scope of the present application.

Claims

1. A power supply electromagnetic interference filter, characterized by, The first differential mode inductor loop, the second differential mode inductor loop and the third differential mode inductor loop are provided, the output ends of the first differential mode inductor loop are electrically connected with the input ends of the second differential mode inductor loop respectively, the output ends of the second differential mode inductor loop are electrically connected with the input ends of the third differential mode inductor loop respectively, and the output ends of the third differential mode inductor loop are connected with a filter inductor in series respectively.

2. A power supply electromagnetic interference filter as defined in claim 1, wherein, The filter input ends and the filter output ends are further provided, the filter input ends are connected with the input ends of the first differential mode inductor loop respectively, and the output ends of the third differential mode inductor loop are connected with a filter inductor in series respectively and connected with the filter output ends respectively.

3. A power supply electromagnetic interference filter as defined in claim 2, wherein, The first differential mode inductor loop comprises a differential mode inductance L D11 , a through-hole capacitor C Y11 , a C Y12 , and a differential mode inductance L D12 ; The filter input two ends are connected with one end of differential mode inductor L D11 and one end of differential mode inductor L D12 respectively. The other end of the differential mode inductor L D11 is electrically connected with the input end of the through-hole capacitor C Y11 The other end of the differential mode inductor L D12 is electrically connected with the input end of the through-hole capacitor C Y12 The ground end of the through-hole capacitor C Y11 is electrically connected with the ground end of the through-hole capacitor C Y12 ​ The output end of the feed-through capacitor C Y11 and the output end of the feed-through capacitor C Y12 are respectively electrically connected across the input of the second differential-mode inductor loop.

4. A power supply electromagnetic interference filter as claimed in claim 2, wherein, The second differential mode inductor loop comprises a differential mode inductance L D21 , a capacitance C Y21 , a capacitance C Y22 , and a differential mode inductance L D22 ; The output of the first differential mode inductor loop is connected to one end of a differential mode inductor L D21 and one end of a differential mode inductor L D22 respectively. The differential mode inductor L D21 The other end is connected to capacitor C Y21 One end of the differential mode inductor L is electrically connected. D22 The other end is connected to capacitor C Y22 One end is electrically connected, capacitor C Y21 The other end is connected to capacitor C Y22 The other end is electrically connected; The differential mode inductor L D21 Close to capacitor C Y21 One end of the differential mode inductor is electrically connected to the input end of the third differential mode inductor circuit, wherein the differential mode inductor L D22 Close to capacitor C Y22 One end is electrically connected to the other end of the input of the third differential mode inductor circuit.

5. A power supply electromagnetic interference filter as defined in claim 2, wherein, The third differential mode inductor loop comprises a differential mode inductance L D31 , a through-hole capacitor C Y31 , a C Y32 , and a differential mode inductance L D32 ; The output of the second differential mode inductor loop is connected to one end of differential mode inductor L D31 and one end of differential mode inductor L D32 respectively. The other end of the differential mode inductor L D31 is electrically connected with the input end of the through-hole capacitor C Y31 The other end of the differential mode inductor L D32 is electrically connected with the input end of the through-hole capacitor C Y32 The ground end of the through-hole capacitor C Y31 is electrically connected with the ground end of the through-hole capacitor C Y32 ​ The output end of the feed-through capacitor C Y31 and the output end of the feed-through capacitor C Y32 are respectively connected in series with a filter inductor and are respectively connected to both ends of the filter output.

6. A power supply electromagnetic interference filter as recited in claim 1, wherein, The housing assembly is further provided, and the input copper bar assembly and the output copper bar assembly are mounted on the two sides of the housing assembly respectively.

7. A power supply electromagnetic interference filter as defined in claim 6, wherein, The housing assembly comprises a shroud and an inner frame, and the inner frame is fixedly connected with the shroud through fasteners.

8. A power supply electromagnetic interference filter as defined in claim 6, wherein, The input copper bar assembly and the output copper bar assembly are both composed of a copper bar sleeve insulation column.

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