Noise Filter

Abstract

To provide a noise filter including a choke coil with a non-circular magnetic core that can solve the circuit board wiring problem.SOLUTION: In a noise filter 4, at least three or more capacitors 31 are provided on the circuit board 3. A choke coil 2 is installed on a circuit board 3 and includes a noncircular magnetic core 21 and at least three or more winding pairs 22 wound around the noncircular magnetic core. At least three or more capacitors 31 are provided adjacent to the choke coil, and a first outgoing end 22a of the winding pairs 22 is connected to the at least three or more capacitors 31.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a noise filter, and more particularly to a noise filter that is applied to a three-phase system and includes a choke coil having a non-circular magnetic core. [Background technology]

[0002] With the progress and development of science and technology, various electrical appliances are very common and frequently used, and it is inevitable to use a power source to operate the electrical appliances properly. However, when an electrical appliance needs to use an AC power source to operate, noise currents may be mixed into the current supplied by the AC power source due to the power supply, the operation of parasitic capacitance or stray capacitance of high-frequency transformers or other components, which is the phenomenon of electromagnetic interference (EMI).

[0003] Generally, noise generated by the use of AC power supplies includes differential mode noise and common mode noise, and an electromagnetic interference filter can function as the first line of defense against electromagnetic radiation from the power supply. The electromagnetic interference filter is mainly composed of a choke coil and a capacitor. The choke coil is an inductive component for suppressing noise generation and is usually composed of at least one winding set, a magnetic core group, and a winding form for winding the winding set.

[0004] 1A and 1B are schematic diagrams showing a conventional electromagnetic interference choke coil from different angles. As shown in Fig. 1A and 1B, a conventional choke coil 1 typically includes a circular magnetic core 11 having a hollow portion and multiple coils 12, and the multiple coils 12 are wound around the hollow circular magnetic core 11.

[0005] Generally, in order to increase the inductance of the conventional choke coil 1, it is necessary to increase the number of turns of the coil 12. However, as can be seen from FIG. 1B, the inner diameter of the circular magnetic core 11 is fixed, which means that the space in the hollow part of the circular magnetic core 11 is limited, and therefore, in this conventional technology, only three sets of coils 121, 122, and 123 can be wound around it. In other words, even if the number of coils 12 or the number of turns is further increased to increase the inductance, it is limited by the inner diameter of the circular magnetic core 11, and it is difficult to further increase the number of coils 12 or the number of turns.

[0006] In addition, because the center of the inner diameter of the circular magnetic core 11 is relatively small (i.e., the space in the hollow part of the circular magnetic core 11 is relatively small), when a large current flows through the coil 12, the wiring of the choke coil 1 on the circuit board 3 (as shown in FIG. 1C) becomes difficult due to the problem of the safe distance between the coils 12, which may affect the layout. For example, as shown in FIG. 1A, the distance between the pins 121a and 122a of the coils 121 and 122 wound around the circular magnetic core 11 is too close, so when the coils are placed on the circuit board 3 as shown in FIG. 1C, wiring becomes difficult due to the problem of the safe distance between the pins 121a and 122a. Furthermore, as can be seen from FIG. 1C, the three sets of coils 12 are wound diagonally to each other, so that the output positions of some of the pins 121a, 122a, etc., installed on the circuit board 3 may be at irregular angles (i.e., not horizontal or vertical), which may affect the installation positions and number of other electronic components 30 or capacitors 31 on the circuit board 3, making it difficult to design the circuit board 3.

[0007] Furthermore, in other conventional technologies, in order to solve problems such as the inductance and safety distance of the conventional choke coil 1, it is necessary to adopt a larger sized circular magnetic core 11 to increase the inductance and satisfy the safety distance. In this way, the volume of the conventional choke coil 1 becomes large, and the volume of the product also becomes large, resulting in a problem that the electronic device cannot be miniaturized.

[0008] Therefore, one of the important issues is how to develop a noise filter that can improve the problems faced by the above-mentioned conventional techniques. Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is to provide a noise filter, particularly for a three-phase system, including a choke coil having a non-circular magnetic core. The large inner diameter of the non-circular magnetic core allows the winding positions of the winding sets to be spaced apart by a certain distance, thereby solving the wiring problems of the circuit board in the prior art.

[0010] Another object of the present invention is to provide a noise filter including a choke coil having a non-circular magnetic core, in which the number and positions of capacitors on a circuit board can be flexibly adjusted by selecting the shape of the non-circular magnetic core, the winding positions of at least three or more winding sets, and the series / parallel method, thereby effectively increasing the space utilization rate of the circuit board, reducing the volume of the entire device, increasing inductance, or shunting current to reduce losses. [Means for solving the problem]

[0011] According to the concept of the present invention, there is provided a noise filter including a circuit board and a choke coil. At least three or more capacitors are provided on the circuit board. The choke coil is mounted on the circuit board and includes a non-circular magnetic core and at least three or more winding sets wound around the non-circular magnetic core. The at least three or more capacitors are provided adjacent to the choke coil, and first output ends of the winding sets are connected to correspond to the at least three or more capacitors.

[0012] According to the concept of the present invention, the non-circular magnetic core has a hollow portion, and when at least three or more winding sets are wound around the non-circular magnetic core, a portion of the winding sets passes through the hollow portion of the non-circular magnetic core.

[0013] According to the concept of the present invention, the non-circular magnetic core is an elliptical annular magnetic core.

[0014] According to the concept of the present invention, the non-circular magnetic core includes an elliptical annular body and a U-shaped extension.

[0015] According to the concept of the present invention, when the choke coil is mounted on a circuit board, at least three or more capacitors are provided adjacent to one side of the choke coil.

[0016] According to the concept of the present invention, when the choke coil is mounted on the circuit board, at least three or more capacitors are provided adjacent to opposite sides of the choke coil.

[0017] According to the concept of the present invention, at least three or more winding sets are arranged in series, parallel, or series and parallel.

[0018] According to an aspect of the present invention, the noise filter further includes an additional circuit board having at least one capacitor for correspondingly connecting to the second output ends of the at least three or more winding sets.

[0019] According to the concept of the present invention, there is provided a noise filter including a circuit board, an additional circuit board, and a choke coil. At least three or more capacitors are provided on the circuit board. At least one capacitor is provided on the additional circuit board. The choke coil is interposed between the circuit board and the additional circuit board, and includes a non-circular magnetic core and at least three or more winding sets wound around the non-circular magnetic core. The at least three or more capacitors on the circuit board and the at least one capacitor on the additional circuit board are both provided adjacent to the choke coil, and first output ends of the at least three or more winding sets are connected to correspond to the at least three or more capacitors on the circuit board, and second output ends of the at least three or more winding sets are connected to correspond to the at least one capacitor on the additional circuit board.

[0020] According to the concept of the present invention, the bottom side of the choke coil is placed corresponding to the circuit board, and the top side of the choke coil is placed corresponding to the additional circuit board. [Brief description of the drawings]

[0021] [Figure 1A] FIG. 1 is a schematic diagram showing a conventional electromagnetic interference choke coil. [Figure 1B] 1A and 1B are schematic diagrams showing a conventional electromagnetic interference choke coil from different angles. [Figure 1C] FIG. 1B is a schematic diagram of the conventional electromagnetic interference choke coil shown in FIG. 1A installed on a circuit board. [Diagram 2] FIG. 1 is a schematic diagram of a noise filter according to a preferred embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic diagram of the choke coil shown in FIG. 2. [Figure 4A] FIG. 11 is a schematic diagram of a choke coil of a noise filter according to a second preferred embodiment of the present invention. [Figure 4B] FIG. 13 is a schematic diagram of a choke coil of a noise filter according to a third preferred embodiment of the present invention. [Figure 5A] FIG. 13 is a schematic side view showing the structure of a noise filter according to a fourth preferred embodiment of the present invention. [Figure 5B] FIG. 5B is a schematic structural plan view of FIG. 5A. [Figure 6] FIG. 13 is a schematic plan view showing the structure of a noise filter according to a fifth preferred embodiment of the present invention. [Figure 7A] FIG. 13 is a schematic side view showing the structure of a noise filter according to a sixth preferred embodiment of the present invention. [Figure 7B] FIG. 7B is a schematic structural plan view of FIG. 7A. [Figure 8] FIG. 13 is a schematic perspective view showing the structure of a noise filter according to a seventh preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Some exemplary embodiments illustrating the features and advantages of the present invention are described in detail in the following description. It should be understood that the present invention can be modified in various ways in different forms without departing from the scope of the present invention, and that the description and drawings are illustrative in nature and are not intended to limit the present invention.

[0023] Please refer to FIG. 2 and FIG. 3. FIG. 2 is a schematic diagram of a noise filter according to a preferred embodiment of the present invention. FIG. 3 is a schematic diagram of the choke coil shown in FIG. 2. In this embodiment, the noise filter 4 is applied to a three-phase system and includes a circuit board 3 and a choke coil 2. The choke coil 2 may be, but is not limited to, a noise filter or inductor for suppressing electromagnetic noise in a circuit board assembly of an electronic device such as a switching power supply. A plurality of electronic components 30 including at least three or more capacitors 31 are provided on the circuit board 3. The choke coil 2 is installed on the circuit board 3 and includes a non-circular magnetic core 21 and at least three or more winding sets 22. The non-circular magnetic core 21 has a hollow portion 210 inside, and the at least three or more winding sets 22 are wound around the non-circular magnetic core 21. The non-circular magnetic core 21 can be any shape other than a circle, and in this embodiment, the form of the non-circular magnetic core 21 is, but is not limited to, an elliptical ring-shaped magnetic core close to a square. When this choke coil 2 is installed on the circuit board 3, at least three or more capacitors 31 are arranged adjacent to one side of the choke coil 2, and the first output ends 22a of the at least three or more winding groups 22 are connected to correspond to the at least three or more capacitors 31.

[0024] 3, in this embodiment, the non-circular magnetic core 21 of the choke coil 2 is an elliptical ring-shaped magnetic core, and includes a first magnetic body part 211, a second magnetic body part 212, a third magnetic body part 213, and a fourth magnetic body part 214, the first magnetic body part 211 and the second magnetic body part 212 are arranged parallel to each other, the third magnetic body part 213 and the fourth magnetic body part 214 are also arranged parallel to each other, the third magnetic body part 213 and the fourth magnetic body part 214 are arranged between the first magnetic body part 211 and the second magnetic body part 212, and the length of the first magnetic body part 211 and the second magnetic body part 212 is greater than the length of the third magnetic body part 213 and the fourth magnetic body part 214. In this embodiment, the connection parts of the first magnetic body part 211, the second magnetic body part 212, the third magnetic body part 213, and the fourth magnetic body part 214 have a fillet structure, but are not limited thereto. Taking this embodiment as an example, the winding set 22 may be a copper foil coil, but is not limited thereto, and the number of the winding sets 22 is six, but the shape of the non-circular magnetic core 21 and the number and material of the winding sets 22 are not limited thereto and can be arbitrarily changed according to the actual implementation situation. In this embodiment, the six winding sets 22 are wound around the non-circular magnetic core 21 at a distance from each other, and a part of each winding set 22 passes through the hollow portion 210 of the non-circular magnetic core 21. In some embodiments, two of the six winding sets 22 are wound around the first magnetic part 211, three are wound around the second magnetic part 212, and one is wound around the third magnetic part 213, so that the exit positions are arranged almost regularly, that is, arranged in the horizontal or vertical direction. However, the winding positions of the winding sets 22 of the present invention are not limited thereto and can be arbitrarily changed according to the actual implementation situation.

[0025] 1C and 2 at the same time. In this embodiment, the non-circular magnetic core 21 is an elliptical annular magnetic core, and the hollow portion 210 inside the core has a relatively large space, so that the winding distance between the winding sets 22 can be adjusted according to the actual wiring requirements. Compared with the conventional technology shown in FIG. 1C, the winding distance of the winding sets 22 in this embodiment is large, so that the problem of wiring difficulties in the conventional technology can be solved. In addition, in this embodiment, six winding sets 22 are wound around the elliptical annular magnetic core, and when the six winding sets 22 are arranged in series, the number of turns is significantly greater than the number of turns of each conventional coil 12. In other words, the winding sets 22 in this embodiment can increase the inductance by connecting multiple winding sets 22 in series. In other embodiments, when the inductance is the same, when the current is too large and the current is to be dispersed to reduce loss, the six winding sets 22 are arranged in parallel, so that the current can be divided and the loss can be reduced. In addition, when comparing the noise filter 4 of this embodiment with the prior art, as can be seen from Fig. 2, since the non-circular magnetic core 21 of this embodiment is an elliptical annular magnetic core, when the six winding sets 22 are wound around the elliptical annular magnetic core, the wire exit positions are arranged almost regularly, that is, arranged in the horizontal or vertical direction, so that when the non-circular magnetic core 21 is installed on the circuit board 3, there is sufficient space around the wire exit positions to install electronic components, so that 14 electronic components can be installed on the circuit board 3 of the present invention, and there is little free space on the circuit board 3. In contrast, as shown in Fig. 1C, the conventional choke coil coil 1 is a circular magnetic core 11, and three sets of coils 12 are wound around the circular magnetic core 11 diagonally, so that the wire exit positions are inclined at an oblique angle, so that the shape of the circular magnetic core 11 and its oblique wire exit positions limit it, making it difficult to arrange electronic components around them, and therefore only 11 electronic components can be installed on the conventional circuit board 3, and there is a lot of space on the circuit board 3 that is difficult to use, and the space utilization rate is obviously poor.As described above, in this embodiment, an elliptical ring-shaped magnetic core is used as the noncircular magnetic core 21, and at least three or more winding sets 22 are wound substantially horizontally or vertically around the noncircular magnetic core 21, thereby effectively improving the space utilization rate of the circuit board 3, increasing the number of electronic components on the circuit board 3, and facilitating the layout and design of the circuit board 3. Of course, the number of electronic components on the circuit board 3 in this embodiment is not limited to the above number, and can be changed as desired depending on the actual implementation situation.

[0026] Please refer to Figures 4A and 4B. Figure 4A is a schematic diagram of a choke coil of a noise filter according to a second preferred embodiment of the present invention. Figure 4B is a schematic diagram of a choke coil of a noise filter according to a third preferred embodiment of the present invention. As can be seen from Figures 4A and 4B, the shape of the non-circular magnetic core 21 of the choke coil 2 of this embodiment is not limited to an elliptical annular magnetic core, and may be an irregular shape. In some embodiments, the non-circular magnetic core 21 of the choke coil 2 is a corrugated annular magnetic core, and has a hollow portion inside, and as shown in Figure 4A, the at least three or more winding sets 22 are wound around the non-circular magnetic core 21, which is a corrugated annular magnetic core, at a distance from each other, and a part of each winding set 22 passes through the hollow portion 210 of the non-circular magnetic core 21. In another embodiment, the non-circular magnetic core 21 of the choke coil 2 is a star-shaped annular magnetic core as shown in Fig. 4B, and the at least three or more winding sets 22 are wound around the non-circular magnetic core 21, which is a star-shaped annular magnetic core, and are spaced apart from each other, and a part of each winding set 22 passes through the hollow portion 210 of the non-circular magnetic core 21. In this way, the non-circular magnetic core 21 of the choke coil 2 of the present invention can be of any shape other than circular, can have various forms, can be arbitrarily changed according to the actual implementation situation, and is not limited to the above-mentioned embodiment.

[0027] Please refer to FIG. 5A and FIG. 5B. FIG. 5A is a schematic side view showing the structure of a noise filter according to a fourth preferred embodiment of the present invention. FIG. 5B is a schematic structural plan view of FIG. 5A. In this embodiment, the noise filter 4 also includes a circuit board 3 and a choke coil 2. The choke coil 2 is installed on the circuit board 3 and includes a non-circular magnetic core 21 and at least three or more winding sets 22, and the at least three or more winding sets 22 are wound around the non-circular magnetic core 21 and installed at a distance from each other, and a part of each winding set 22 passes through the hollow part 210 of the non-circular magnetic core 21. In this embodiment, the number of turns of any two winding sets 22 is the same, so that they can be arranged in series or in parallel according to different situations to increase the inductance or split the current, as in the above-mentioned embodiment. Of course, in other embodiments, they can also be arranged in series and in parallel, and can be arbitrarily changed according to the actual implementation situation, and are not limited thereto. The circuit board 3 has at least three or more capacitors 31. Taking this embodiment as an example, the number of the at least three or more capacitors 31 is three, the three capacitors 31 are provided adjacent to one side of the choke coil 2, the first output ends 22a of the at least three or more winding sets 22 are connected to the three capacitors 31, and the second output ends 22b of the at least three or more winding sets 22 can be connected to a remote circuit board (not shown) through wiring, thereby correspondingly connecting to a capacitor (not shown) on the remote circuit board. In other words, taking this embodiment as an example, it mainly indicates that one side of the choke coil 2 is directly electrically connected to the at least three capacitors 31 on the circuit board 3, and the other side is electrically connected to the remote circuit board (not shown) through wiring. However, in other embodiments, the circuit board 3 may be provided with four, five, or six capacitors 31, which may be installed correspondingly on both opposing sides of the winding sets 22 or on any two sides. The number and installation positions of the capacitors 31 are adjusted mainly according to the shape of the non-circular magnetic core 21 of the choke coil 2 and the exit positions of the winding sets 22, but are not limited thereto.In some embodiments, the capacitor 31 may include a Y capacitor 31a and an X capacitor 31b, and in this case, the first output ends 22a of the at least three or more winding sets 22 are simultaneously connected to the Y capacitor 31a and the X capacitor 31b, but are not limited thereto. In other embodiments, the choke coil 2 may be a differential mode inductor or a common mode inductor, and may be arbitrarily combined with the desired Y capacitors 31a and X capacitors 31b, and the number and installation method thereof are not limited thereto.

[0028] Please refer to FIG. 6. FIG. 6 is a schematic plan view showing the structure of a noise filter according to a fifth preferred embodiment of the present invention. In this embodiment, the structure and arrangement of the circuit board 3 and the choke coil 2 of the noise filter 4 are almost the same as those of the above embodiment. However, in this embodiment, the form of the non-circular magnetic core 21 of the choke coil 2 is a combination of an elliptical ring-shaped magnetic core and a U-shaped magnetic core. In other words, the non-circular magnetic core 21 has an elliptical ring-shaped main body 215, and a part of the elliptical ring-shaped main body 215 protrudes outward to form a U-shaped extension part 216, that is, both ends of the elliptical ring-shaped main body 215 are connected to both ends of the U-shaped extension part 216. In this embodiment, at least three or more winding sets 22 are wound around the elliptical ring-shaped main body 215 at a distance from each other, and are not wound around the U-shaped extension part 216. In other embodiments, the winding sets 22 may be wound around the U-shaped extension part 216 so as to match the wiring arrangement of the circuit board 3 and the position of the capacitor 31 thereon. Therefore, the shape of the non-circular magnetic core 21 and the winding positions of the at least three winding sets 22 can be changed arbitrarily according to the arrangement of the circuit board 3.

[0029] Please refer to Figures 7A and 7B. Figure 7A is a schematic side view showing the structure of a noise filter according to a sixth preferred embodiment of the present invention. Figure 7B is a schematic structural plan view of Figure 7A. As shown in Figures 7A and 7B, the noise filter 5 of this embodiment includes not only the circuit board 3 and the choke coil 2, but also an additional circuit board 6. As can be seen from Figure 7A, the choke coil 2 of this embodiment is interposed between the circuit board 3 and the additional circuit board 6 to form a sandwich-type noise filter 5. In this embodiment, the top side of the choke coil 2 is connected and installed corresponding to the additional circuit board 6, and the bottom side is installed corresponding to the circuit board 3, so that the choke coil 2 is interposed between the circuit board 3 and the additional circuit board 6. 7B , the choke coil 2 also includes a noncircular magnetic core 21 and at least three or more winding sets 22, and in this embodiment, the number of the at least three or more winding sets 22 is six, that is, the six winding sets 22 in this embodiment are wound around the noncircular magnetic core 21 and spaced apart from each other, and a part of each winding set 22 passes through the hollow portion 210 of the noncircular magnetic core 21. As in the previous embodiment, the circuit board 3 has at least three or more capacitors 31, and in this embodiment, the circuit board 3 has three capacitors, and the three capacitors 31 are provided adjacent to one side of the choke coil 2 and connected to correspond to the first output ends 22a of the six winding sets 22. Similarly, the additional circuit board 6 is also provided with at least three or more capacitors 61. In this embodiment, the number of the at least three or more capacitors 61 is three. As can be seen from FIG. 7A, the three capacitors 61 are installed corresponding to both opposing sides of the choke coil 2, that is, two capacitors 61 are installed on one side of the choke coil 2, and the other capacitor 61 is installed on the other side of the choke coil 2, so that the choke coil 2 is interposed between the three capacitors 61. The three capacitors 61 are connected corresponding to the second output ends 22b of the six winding sets 22. In this embodiment, the capacitors 31 on the circuit board 3 and the capacitors 61 on the additional circuit board 6 are both installed adjacent to the choke coil 2, so that electromagnetic interference can be effectively suppressed.In some embodiments, the capacitor 31 and the capacitor 61 can be arranged adjacent to the choke coil 2 in a locking manner, but are not limited thereto. In addition, the sandwich arrangement manner of the present embodiment allows the component installation positions and numbers of the circuit board 3 and the additional circuit board 6 to be adjusted more flexibly. For example, if the space of the circuit board 3 is not enough to arrange six capacitors 31, for example, if only three or four capacitors can be arranged, the additional circuit board 6 can be installed to move the three or two capacitors that cannot be installed to the additional circuit board 6, thereby adjusting or increasing the branch capacitor 61. In this way, the three-dimensional sandwich installation manner can change the horizontal output direction of the winding set 22 to a vertical output direction, and further reduce the volume of the entire noise filter 5 and improve the space utilization rate of the circuit board 3 and the additional circuit board 6.

[0030] Please refer to Fig. 8. Fig. 8 is a schematic perspective view showing the structure of a noise filter according to a seventh preferred embodiment of the present invention. In this embodiment, the structure of the circuit board 3 and the choke coil 2 of the noise filter 7 is almost the same as that of the above embodiment, that is, the circuit board 3 includes at least three or more capacitors 31, the choke coil 2 is installed on the circuit board 3, and includes a non-circular magnetic core 21 and at least three or more winding sets 22, the at least three or more winding sets 22 are wound around the non-circular magnetic core 21 and installed at a distance from each other, and a part of each winding set 22 passes through the hollow portion 210 of the non-circular magnetic core 21. However, in this embodiment, the number of the at least three or more capacitors 31 on the circuit board 3 is three, one of which is installed on one side of the choke coil 2, and the other two capacitors 31 are installed correspondingly on the other side of the choke coil 2. In other words, the three capacitors 31 are provided adjacent to opposite sides of the choke coil 2, with the at least three or more winding sets 22 sandwiched therebetween, and are connected correspondingly to first output ends 22a (not shown) of the at least three or more winding sets 22. In this manner, the number and installation positions of the capacitors 31 on the circuit board 3 can be arbitrarily changed according to the size of the circuit board 3 and the actual situation, and these changes are not limited to the above, but require that at least three capacitors 31 be installed adjacent to the choke coil 2 to achieve the effect of suppressing electromagnetic interference.

[0031] As described above, the present invention provides a noise filter including a circuit board and a choke coil, the choke coil including a non-circular magnetic core and at least three or more winding sets, the at least three or more winding sets being wound around the non-circular magnetic core and connected to and adjacent to a capacitor on the circuit board. Because the inner diameter of the non-circular magnetic core is large, the winding positions of the at least three or more winding sets can be spaced apart by a certain distance, which solves the wiring problem of the circuit board in the prior art. In addition, by installing at least three or more winding sets in series, the inductance can be significantly increased, or by installing at least three or more winding sets in parallel, the current can be divided to reduce loss. In this way, the shape of the non-circular magnetic core of the choke coil of the present invention and the winding positions and series / parallel method of the at least three or more winding sets can flexibly adjust the number and positions of the capacitors on the circuit board, effectively increasing the space utilization rate of the circuit board, while suppressing electromagnetic interference, reducing the volume of the entire device, increasing inductance, or dividing the current to reduce loss.

[0032] The present invention may be modified in various ways by those skilled in the art, without departing from the scope thereof as defined by the claims. [Explanation of symbols]

[0033] 1: Conventional choke coil 11:Circular magnetic core 12, 121, 122, 123: Coil 121a, 122a: pin 2: Choke coil 21: Non-circular magnetic core 210: Hollow part 211: First magnetic body part 212:Second magnetic body part 213:Third magnetic body part 214:Fourth magnetic body part 215: Elliptical annular body 216: U-shaped extension 22: Winding set 22a: 1st output end 22b: 2nd output end 3: Circuit board 30: Electronic Components 31, 61: Capacitor 31a: Y capacitor 31b: X capacitor 4, 5, 7: Noise filters 6: Additional circuit board

Claims

1. A noise filter including a circuit board and a choke coil, the circuit board has at least three capacitors; the choke coil is disposed on the circuit board and includes a non-circular magnetic core and at least three or more winding sets wound around the non-circular magnetic core; the non-circular magnetic core includes a first magnetic body portion, a second magnetic body portion, a third magnetic body portion, and a fourth magnetic body portion, the first magnetic body portion and the second magnetic body portion are arranged in parallel to correspond to each other, the third magnetic body portion and the fourth magnetic body portion are arranged in parallel to correspond to each other, and the third magnetic body portion and the fourth magnetic body portion are respectively arranged between the first magnetic body portion and the second magnetic body portion, At least one winding set is wound around each of the first magnetic body portion, the second magnetic body portion, and the third magnetic body portion, the at least three or more capacitors are provided in an area adjacent to the choke coil, and first output ends of the at least three or more winding sets are connected to corresponding ones of the at least three or more capacitors.

2. 2. The noise filter according to claim 1, wherein the non-circular magnetic core has a hollow portion, and a part of the winding set passes through the hollow portion of the non-circular magnetic core.

3. 2. The noise filter according to claim 1, wherein the non-circular magnetic core is an elliptical ring-shaped magnetic core.

4. 2. The noise filter of claim 1, wherein the non-circular magnetic core includes an elliptical annular body and an outwardly extending U-shaped extension.

5. The noise filter according to claim 1 , wherein the at least three capacitors are provided adjacent to one side of the choke coil.

6. 2. The noise filter according to claim 1, wherein the at least three capacitors are provided adjacent to opposite sides of the choke coil.

7. 2. The noise filter according to claim 1, wherein the at least three or more winding sets are arranged in series, in parallel, or in series and in parallel.

8. 2. The noise filter according to claim 1, further comprising an additional circuit board, the additional circuit board having at least one capacitor for correspondingly connecting to second output ends of the at least three winding sets.

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