active filter module

Abstract

The present disclosure relates to an active filter module having a housing, a printed circuit board (1) arranged within the housing, and a grounding device comprising: - a grounding terminal (2) arranged on the printed circuit board adjacent to a board edge (11) of the printed circuit board (1) and provided with a first threaded hole (20), - a face plate (4) of the housing oriented perpendicular to the printed circuit board (1) and opposite to the board edge (11), the face plate being electrically connected to ground, the face plate being spaced apart from the grounding terminal (2) by a distance (d) in a first direction perpendicular to the face plate (4), a first through hole (40) being provided in the face plate, and - a grounding screw (5) being detachably screwable through the first through hole (40) into the first threaded hole (20) or unscrevable from the first threaded hole, such that in a screwed-in state a head of the grounding screw (5) rests on an outer side of the face plate (4) so that the face plate (4) is electrically connected to the grounding terminal (2) by the grounding screw (5), and in an unscrewed state the face plate is electrically disconnected from the grounding terminal.

Description

Technical Field

[0001] This disclosure relates to the electrical field, specifically to an active filter module. Background Technology

[0002] An active filter includes one or more active filter modules.

[0003] For active power filter modules, the grounding screw needs to be removed before the withstand voltage test. The grounding screw should be reinstalled after the test passes.

[0004] The original design for removing and installing the grounding screw involved drilling a hole in the upper partition, and then using a screwdriver to access the lower PCB (printed circuit board) through the hole in the upper partition to remove and install the grounding screw. However, this solution carries the risk of screws falling out, is inconvenient due to the limited space, and requires removing the module's top cover, posing safety concerns. Utility Model Content

[0005] Therefore, this disclosure aims to solve the aforementioned problems existing in existing active filter modules, with the purpose of achieving safe, convenient, and fast grounding.

[0006] The active filter module according to this disclosure has a housing, a printed circuit board disposed within the housing, and a grounding device. The grounding device includes: a grounding terminal disposed on the printed circuit board adjacent to the board edge and having a first threaded hole; a panel of the housing oriented perpendicular to the printed circuit board and opposite to the board edge, the panel being electrically connected to ground, the panel being spaced apart from the grounding terminal along a first direction perpendicular to the panel, and having a first through hole in the panel; and a grounding screw, the grounding screw being detachably screwed into the first threaded hole through the first through hole or unscrewed from the first threaded hole, such that in the screwed-in state, the head of the grounding screw abuts against the outer side of the panel, thereby electrically connecting the panel to the grounding terminal through the grounding screw, and in the unscrewed state, electrically disconnecting the panel from the grounding terminal.

[0007] With the technical solution disclosed herein, when the filter module needs to undergo withstand voltage testing, it is only necessary to unscrew the grounding screw from the outside of the module housing. This solution is simple and convenient to operate, eliminates the risk of screws falling inside the module, and can be operated from the outside of the module without opening the cover for testing, making it safe and reliable.

[0008] For example, according to one embodiment of the present disclosure, the grounding device includes a first insulating pad fixedly disposed between a grounding terminal and a panel, the first insulating pad having a dimension in a first direction equal to the distance therebetween, and the first insulating pad having a second through hole extending in the first direction, through which a grounding screw can be screwed into a first threaded hole.

[0009] Therefore, it not only provides reliable electrical insulation when the grounding screw is removed or during withstand voltage testing, but also provides mechanical stability. Without the first insulating pad, if the grounding screw is over-tightened when screwed into the first threaded hole of the grounding terminal, the grounding terminal will be pulled towards the housing panel, causing deformation and damage to the solder joint between the grounding terminal and the PCB. Conversely, with the first insulating pad, even if over-tightened, the grounding terminal will not be pulled or deformed due to the pad's resistance.

[0010] For example, according to one embodiment of the present disclosure, the first insulating pad is fixed to the inner side of the panel by a threaded connection device, the threaded connection device including: a fixing screw, a third through hole opened on the panel and a second threaded hole provided in the first insulating pad, the fixing screw can be screwed into the second threaded hole of the first insulating pad through the third through hole from the outside of the housing along a first direction, wherein, in the screwed-in state, the head of the fixing screw abuts against the outer side of the panel and the shank of the fixing screw does not extend beyond the first insulating pad.

[0011] This allows for the detachable fixing of the first insulating pad, which has the advantage of enabling the replacement of the first insulating pad.

[0012] Alternatively, the first insulating pad can be detachably fixed to another panel oriented perpendicularly to the panel.

[0013] In principle, it is also possible to fix the first insulating pad in a non-removable manner, for example, by attaching the first insulating pad to the panel or other panels.

[0014] For example, according to one embodiment of this disclosure, two threaded connection devices are provided, which are disposed on the same side or different sides relative to the first through hole.

[0015] This prevents the first insulating pad from rotating due to factors such as loose fixing screws, thus ensuring that the first insulating pad is fixed in position. Of course, it is also feasible to use more than two threaded connection devices to fix the first insulating pad.

[0016] For example, according to one embodiment of this disclosure, the grounding screw is designed as a countersunk screw and the first through hole is designed as a tapered hole that mates with the tapered surface of the grounding screw head, and / or the fixing screw is designed as a countersunk screw and the third through hole is designed as a tapered hole that mates with the tapered surface of the fixing screw head.

[0017] Therefore, in the installed state, the driving surface (i.e., the surface facing away from the screw shank) of the grounding screw and / or fixing screw head is flush with the outer side of the panel. This has the advantage of aesthetics, and on the other hand, due to the tapered surface of the countersunk screw, the contact area between the screw head and the panel is increased, thereby providing good electrical contact.

[0018] For example, according to one embodiment of the present disclosure, the grounding terminal is U-shaped when viewed in a second direction perpendicular to the printed circuit board, including a bottom section and extension sections connected to both ends of the bottom section, wherein the bottom section faces the panel and its side facing the panel abuts against a first insulating pad, and wherein a first threaded hole of the grounding terminal is formed in the bottom section.

[0019] This not only provides mechanical stability to the terminals on the PCB, but also allows for quick installation and removal of the grounding screw due to the short distance between the first threaded hole and the panel. Furthermore, it is advantageous to use commercially available U-shaped terminal standard parts as the grounding terminals.

[0020] Alternatively, the U-shaped grounding terminal can be arranged in other different orientations, such that the side of one extension of the U-shape or the end faces of both extensions abut against the first insulating pad, and / or the first threaded hole of the grounding terminal can be formed in the extension, provided that the first threaded hole of the grounding terminal is open in the first direction and at least a portion of the grounding terminal abuts against the first insulating pad. It is also feasible in principle to use other shapes of grounding terminals, such as H-shaped grounding terminals.

[0021] For example, according to one embodiment of the present disclosure, a terminal block is provided on the outer surface of the housing of the active filter module, which is connected to an external power supply line and an internal power supply line respectively.

[0022] For example, according to one embodiment of the present disclosure, the active filter module includes a fuse disposed outside the housing, the fuse being electrically connected to a wiring terminal via a first terminal and to an external power supply line via a second terminal.

[0023] For example, according to one embodiment of the present disclosure, the first terminal is electrically connected to the wiring terminal by a screw.

[0024] For example, according to one embodiment of the present disclosure, a second insulating pad protruding from the housing is further provided on the outer surface of the housing, wherein the second terminal is fixed to the second insulating pad by screws so as to space the second terminal from the housing.

[0025] For example, according to one embodiment of this disclosure, the active filter module further includes a protective cover that is mounted to the housing and covers the fuse.

[0026] For example, according to one embodiment of this disclosure, a varistor is connected in parallel between the internal power line and the ground terminal downstream of the wiring terminal. Attached Figure Description

[0027] The above and other features and advantages of this disclosure will become more apparent from the following detailed description of exemplary embodiments taken in conjunction with the accompanying drawings, which are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way. The following drawings are not intentionally drawn to scale with actual dimensions; their focus is on illustrating the gist of this disclosure. In the figures:

[0028] Figure 1 A portion of an active filter module according to an embodiment of the present disclosure is shown, wherein the panel is shown semi-transparently and thus the interior of the module can be seen;

[0029] Figure 2 A perspective view of the overall appearance of an active filter module according to an embodiment of the present disclosure is shown.

[0030] Figure 3 An active filter module according to an embodiment of the present disclosure is shown. Figure 1 A matching view, but showing an exploded view;

[0031] Figure 4 Another exploded view of an active filter module according to an embodiment of the present disclosure is shown, wherein the housing and therefore the panel are removed;

[0032] Figure 5 A partial cross-sectional view of the grounding arrangement of an active filter module according to an embodiment of the present disclosure is shown;

[0033] Figure 6 Another partial cross-sectional view of the grounding arrangement of an active filter module according to an embodiment of the present disclosure is shown;

[0034] Figure 7 A partial exploded perspective view shows the mounting structure of the fuse of an active filter module according to an embodiment of the present disclosure;

[0035] Figure 8 A schematic circuit diagram of an active filter module according to an embodiment of the present disclosure is shown.

[0036] In each figure, the same or similar parts are indicated by the same reference numerals. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings.

[0038] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, “an” or “a” and similar terms do not necessarily indicate a quantity limitation. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, which may change accordingly when the absolute position of the described object changes.

[0039] like Figures 1 to 3 As shown, the active filter module according to this disclosure has a housing, a printed circuit board 1 disposed within the housing, and a grounding device. The grounding device includes: a grounding terminal 2 disposed on the printed circuit board 1 adjacent to the board edge 11 and having a first threaded hole 20; a panel 4 of the housing oriented perpendicular to the printed circuit board 1 and opposite to the board edge 11, the panel being electrically connected to ground, and the panel being spaced from the grounding terminal 2 by a distance d along a first direction perpendicular to the panel 4 (see [reference]). Figure 5 The panel has a first through hole 40 and a grounding screw 5. The grounding screw can be detachably screwed into the first threaded hole 20 through the first through hole 40 or screwed out of the first threaded hole 20. When screwed in, the head of the grounding screw 5 rests against the outside of the panel 4, so that the panel 4 is electrically connected to the grounding terminal 2 through the grounding screw 5, and when screwed out, the panel 4 is electrically disconnected from the grounding terminal 2.

[0040] The active filter module can be rack-mounted or wall-mounted. The active filter module has a housing, which can have multiple panels. In the example shown, panel 4 is a side panel of the housing, but it could also be a front or rear panel, depending on the location of the grounding terminal 2 on the PCB, i.e., which board edge it is adjacent to. In the assembled state of the active filter module, only the head of the grounding screw 5 and, if necessary, the heads of the fixing screws 61 and 62 are visible from the outside of the housing.

[0041] As shown in the figure, the printed circuit board 1, or PCB, is horizontally arranged inside the housing. Various electronic components 10 are integrated on the printed circuit board 1, therefore the PCB is also called a PCBA, or printed circuit board assembly. For example, a copper-filled area 12 is provided on the printed circuit board 1, wherein the copper-filled area 12 is located in the edge region adjacent to the board edge 11 of the printed circuit board 1, and the ground terminal 2 is soldered to the copper-filled area 12.

[0042] Panel 4 is grounded in a conventional manner, for example, through a PE wire terminal (not shown) provided on the housing, i.e., connected to the earth.

[0043] Thus, with the grounding screw 5 screwed into the first threaded hole 20, a reliable grounding connection is formed from the grounding terminal 2 through the grounding screw 5, the panel 4, and then to the ground. For withstand voltage testing, the grounding screw 5 is unscrewed from the first threaded hole 20 from the outside of the panel 4, without needing to enter the module.

[0044] According to an embodiment of the present disclosure, the grounding device includes a first insulating pad 3, which is fixedly arranged between the grounding terminal 2 and the panel 4. The first insulating pad 3 has a dimension along a first direction equal to the distance d, and the first insulating pad 3 has a second through hole 30 extending along the first direction, through which a grounding screw 5 can be screwed into a first threaded hole 20.

[0045] The first insulating pad 3 is made of, for example, a material with an FR4 flame retardant rating, which is commonly used in the manufacture of printed circuit boards. The first insulating pad 3 is designed, for example, to completely cover the grounding terminal 2 along the first direction in terms of its dimension perpendicular to the first direction.

[0046] According to an embodiment of the present disclosure, the grounding terminal 2 is U-shaped when viewed along a second direction perpendicular to the printed circuit board 1, including a bottom section and extension sections connected to both ends of the bottom section, wherein the bottom section faces the panel 4 and its side facing the panel 4 abuts against the first insulating pad 3, and wherein the first threaded hole 20 of the grounding terminal 2 is formed in the bottom section.

[0047] For example, the first insulating pad 3 is constructed in the shape of a cuboid, with its two parallel faces respectively abutting against the inner side of the panel 4 and the side of the bottom section of the grounding terminal 2 facing the panel 4. However, this disclosure is not limited to this, and other shapes of the first insulating pad 3 are also possible.

[0048] The first insulating pad 3 is preferably fixed to the inside of the panel 4 by two threaded connections. In the example shown, the two threaded connections are located on the same side of the first through hole 30.

[0049] The first threaded connection device includes: a fixing screw 61, a through hole 41 opened on the panel 4, and a threaded hole 31 provided in the first insulating pad 3. The fixing screw 61 can pass through the third through hole 41 from the outside of the housing and be screwed into the threaded hole 31 of the first insulating pad 3. In the screwed-in state, the head of the fixing screw 61 abuts against the outer side of the panel 4 and the shank of the fixing screw 61 does not extend beyond the first insulating pad 3.

[0050] Similarly, the second threaded connection device includes: a fixing screw 62, a through hole 42 opened on the panel 4, and a threaded hole 32 provided in the first insulating pad 3. The fixing screw 62 can pass through the through hole 42 from the outside of the housing and be screwed into the threaded hole 32 of the first insulating pad 3. In the screwed-in state, the head of the fixing screw 62 abuts against the outside of the panel 4 and the shank of the fixing screw 62 does not extend beyond the first insulating pad 3.

[0051] The dimensions of the components of the first threaded connection device and the second threaded connection device can be the same or different. The first threaded connection device and the second threaded connection device can also be located on different sides relative to the first through hole 40. Additional threaded connection devices can also be provided, but using two threaded connection devices can ensure the fixation of the first insulating pad 3 with less cost.

[0052] The following is for reference Figure 5 and Figure 6 Describe the design of grounding screw 5, fixing screws 61 and 62, through holes 30, 40, 41, and 42, and threaded holes 31 and 32. Figure 5 and Figure 6 In the middle, grounding screw 5 and fixing screws 61 and 62 are all in the installation state.

[0053] As shown in the figure, the grounding screw 5 is designed as a countersunk screw and the first through hole 40 is designed as a tapered hole that mates with the tapered surface of the head of the grounding screw 5. Similarly, the fixing screws 61 and 62 are designed as countersunk screws and the through holes 41 and 42 are designed as tapered holes that mate with the tapered surface of the head of the corresponding fixing screw.

[0054] For example, an M4×16 countersunk screw is used as the grounding screw 5, and an M4×6 countersunk screw is used as the fixing screws 61 and 62. As shown in the figure, since the thickness of the panel 4 is less than the axial dimension of the screw head of the fixing screws 61 and 62, the threaded holes 31 and 32 have a tapered section adjacent to the panel 4. This tapered section mates with the corresponding screw head protruding beyond the tapered surface section of the panel 4 in the installed state. The same applies to the grounding screw 5, except that since the diameter of the second through hole 30 of the first insulating pad 3 for the grounding screw 5 is designed to be larger than the diameter of the shank of the grounding screw 5, the second through hole 30 does not need to have a tapered section similar to that of the threaded holes 31 and 32 when it has a specific hole diameter. For an M4×16 countersunk screw as the grounding screw 5, the diameter of the second through hole 30 can be, for example, 6 mm.

[0055] In the example shown, threaded holes 31 and 32 are also designed as through holes. However, blind holes can also be considered. In the installed state, the fixing screws 61 and 62 do not extend beyond the corresponding threaded holes on the side facing away from panel 4.

[0056] In embodiments of this disclosure, the active filter module may further include a fuse 7 for protecting the active filter module. Existing active filter devices typically use fuses built into the PCB, meaning the fuse is placed inside the active filter device. This arrangement occupies internal space and is inconvenient for fuse maintenance and replacement. Therefore, according to embodiments of this disclosure, the fuse 7 can be disposed outside the housing of the active filter module, for example, on the outer surface of the rear panel, facilitating fuse maintenance and replacement, solving the problem of needing to open the cover to replace the fuse, and reducing operational difficulty. Furthermore, the external fuse design reduces the risk of electric shock, avoids contact with live components inside the module, and thus prevents secondary damage and fault propagation. Other advantages include: ease of replacing fuses of different specifications, allowing for flexible matching of circuit parameters; and simplifies the internal structure and optimizes the layout compared to existing built-in solutions.

[0057] Specifically, the fuse 7 may include a first terminal 71 electrically connected to a terminal block 81 on the active filter module and a second terminal 72 electrically connected to an external power supply line. A terminal block 81 connected to the internal power supply line is provided on the outer surface of the housing (e.g., the outer surface of the rear panel). The first terminal 71 is electrically connected to the terminal block 81 via screws and thus connected to the internal power supply line. A second insulating pad 82 protruding from the housing may also be provided on the outer surface of the housing (e.g., the outer surface of the rear panel), that is, the second insulating pad 82 has a certain thickness in the direction protruding from the outer surface of the housing. Thus, the second terminal 72 can be fixed to the second insulating pad 82 with screws to space the second terminal 72 from the housing, thereby providing a sufficient safety distance to prevent short circuits.

[0058] like Figure 7 As shown, terminal 81 is positioned above and second insulating pad 82 is positioned below, thus forming an upper-entry wiring configuration. However, the positions of terminal 81 and second insulating pad 82 can also be interchanged, thus forming a lower-entry wiring configuration. Upper and lower entry configurations are suitable for top and bottom entry designs of the entire active power filter, respectively.

[0059] like Figure 7 As shown, three fuses 7 can be provided, for example, to correspond to three-phase electricity, i.e., lines A, B, and C. Accordingly, three terminals 81 can be provided, and three threaded holes are provided on a large second insulating pad 82.

[0060] Furthermore, such as Figure 7 As shown, the active filter module may also include a protective cover 83, which can be mounted to the housing and cover the fuse 7 to provide protection.

[0061] Figure 8 A schematic circuit diagram of an active filter module according to an embodiment of the present disclosure is shown. In the three-phase four-wire system shown, downstream of terminal 81, one varistor is connected in parallel between lines A, B, C, and N and ground terminal 2 (not shown), i.e., a total of four varistors.

[0062] The active filter module has a varistor designed inside the ABCN line pair PE to limit surge voltage in the external environment and protect the equipment from damage. Thus, when the grounding screw 5 is screwed into the first threaded hole 20, a surge discharge path is formed through the varistor, grounding terminal 2, grounding screw 5, and panel 4 (shown only schematically in the circuit diagram).

[0063] The varistor's trigger voltage is 625V, but the safety withstand voltage test requires 2000V for 1 minute (industry standard JB / T11067-2011). To ensure the varistor is not damaged during the safety test and that the test passes without interference, the grounding screw 5 is unscrewed from the first threaded hole 20 of the grounding terminal 2 during the test. This puts the varistor in an open-circuit state, thus preventing it from being affected. After the test, the grounding screw 5 is screwed back on, and the varistor normally performs its protective function.

[0064] Certain features, structures, or characteristics in one or more embodiments of this disclosure may be appropriately combined.

[0065] The foregoing description is illustrative of the present disclosure and should not be construed as limiting it. While several exemplary embodiments of the present disclosure have been described, those skilled in the art will readily understand that many modifications may be made to the exemplary embodiments without departing from the novel teachings and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure as defined in the claims. It should be understood that the foregoing description is illustrative of the present disclosure and should not be construed as limiting it to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of this disclosure.

Claims

1. An active filter module having a housing, a printed circuit board (1) disposed within the housing, and a grounding device comprising: - Grounding terminal (2), which is arranged on the printed circuit board (1) adjacent to the board edge (11) and has a first threaded hole (20); - A panel (4) of the housing, oriented perpendicular to the printed circuit board (1) and opposite to the edge (11) of the board, the panel being electrically connected to the ground, the panel being spaced a distance (d) from the grounding terminal (2) along a first direction perpendicular to the panel (4), and a first through hole (40) being provided on the panel; and - A grounding screw (5) that can be detachably screwed into or out of the first threaded hole (20) through the first through hole (40), such that when screwed in, the head of the grounding screw (5) rests against the outside of the panel (4), thereby electrically connecting the panel (4) to the grounding terminal (2) through the grounding screw (5), and when screwed out, electrically disconnecting the panel (4) from the grounding terminal (2).

2. The active filter module according to claim 1, characterized in that, The grounding device includes a first insulating pad (3) which is fixedly arranged between the grounding terminal (2) and the panel (4). The first insulating pad (3) has a dimension in a first direction equal to the distance (d) and has a second through hole (30) extending in the first direction. A grounding screw (5) can pass through the second through hole (30) and be screwed into a first threaded hole (20).

3. The active filter module according to claim 2, characterized in that, The first insulating pad (3) is fixed to the inner side of the panel (4) by a threaded connection device. The threaded connection device includes a fixing screw (61), a third through hole (41) opened on the panel (4), and a second threaded hole (31) provided in the first insulating pad (3). The fixing screw (61) can pass through the third through hole (41) from the outside of the housing and be screwed into the second threaded hole (31) of the first insulating pad (3). In the screwed-in state, the head of the fixing screw (61) abuts against the outside of the panel (4) and the shank of the fixing screw (61) does not extend beyond the first insulating pad (3).

4. The active filter module according to claim 3, characterized in that, Two threaded connection devices are provided, which are located on the same side or different sides relative to the first through hole (40).

5. The active filter module according to claim 3, characterized in that, The grounding screw (5) is designed as a countersunk screw and the first through hole (40) is designed as a tapered hole that mates with the tapered surface of the grounding screw head, and / or the fixing screw (61) is designed as a countersunk screw and the third through hole (41) is designed as a tapered hole that mates with the tapered surface of the fixing screw head.

6. The active filter module according to claim 1, characterized in that, The grounding terminal (2) is U-shaped when viewed in a second direction perpendicular to the printed circuit board (1), including a bottom section and extension sections connected to both ends of the bottom section, wherein the bottom section faces the panel (4) and its side facing the panel (4) abuts against the first insulating pad (3), and wherein a first threaded hole (20) is formed in the bottom section.

7. The active filter module according to claim 1, characterized in that, A terminal block (81) is provided on the outer surface of the housing of the active filter module, which is connected to the external power line and the internal power line respectively.

8. The active filter module according to claim 7, characterized in that, The active filter module includes a fuse (7) disposed outside the housing, which is electrically connected to a wiring terminal (81) via a first terminal (71) and to an external power supply line via a second terminal (72).

9. The active filter module according to claim 8, characterized in that, The first terminal (71) is electrically connected to the terminal (81) via a screw.

10. The active filter module according to claim 8, characterized in that, A second insulating pad (82) protruding from the housing is also provided on the outer surface of the housing, wherein the second terminal (72) is fixed to the second insulating pad (82) by screws so as to separate the second terminal (72) from the housing.

11. The active filter module according to claim 8, characterized in that, The active filter module also includes a protective cover (83) which is mounted to the housing and covers the fuse (7).

12. The active filter module according to claim 7, characterized in that, Downstream of terminal (81), a varistor is connected in parallel between the internal power line and the ground terminal (2).

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