Common mode inductor

Abstract

The utility model relates to the field of circuit design, in particular to a common mode inductor which comprises a bottom plate, a magnetic ring, a first wire, a second wire and a third wire. The magnetic ring is perpendicular to the bottom plate. The first wire, the second wire and the third wire are uniformly wound on the magnetic ring respectively to form a first winding, a second winding and a third winding respectively. The first winding, the second winding and the third winding are sequentially and evenly distributed at intervals in the circumferential direction of the magnetic ring. The first wire, the second wire and the third wire are all enameled wires. The first wire, the second wire, and the third wire are respectively connected with the live wire, the zero wire, and the ground wire in an alternative and non-repeated manner. Three groups of varnished wire windings which are sequentially and uniformly arranged at intervals are adopted to be respectively and correspondingly connected with a live wire, a zero wire and a ground wire, so that the allowance between the EMC conduction and radiation quantity and a standard value is improved, the aim of miniaturization design of the size is realized, and the device can be directly mounted on a PCBA (Printed Circuit Board Assembly).

Description

Technical Field

[0001] The utility model relates to the technical field of circuit design, in particular to a common mode inductor. Background Art

[0002] One of the requirements in the EMC (Electromagnetic Compatibility) standard is that the equipment or system must operate in accordance with the requirements in its electromagnetic environment and must not produce intolerable electromagnetic disturbance to any equipment in its environment. Nowadays, most countries have EMC standard requirements for electronic products sold on the market, especially some European and American countries have strict EMC standards. Therefore, this requires manufacturers to make corresponding restrictions on EMC conduction and radiation when designing circuits, so that the amount of EMC conduction and radiation is controlled below the standard value (threshold), that is, to increase the margin between the amount of EMC conduction and radiation and the standard value.

[0003] In circuit design, in order to reduce the amount of EMC conduction and radiation, common-mode inductors (also called common-mode choke coils) are usually added to the circuit. Traditional common-mode inductors include: a magnetic ring, and a neutral wire and a live wire respectively wound around the magnetic ring. The defect of this design is that since the neutral wire and the live wire need to be wrapped with an insulating layer (i.e., a plastic shell), the wire diameter is large, which leads to the need to use a magnetic ring with a larger diameter. Therefore, the overall volume of the traditional common-mode inductor is large and cannot be directly installed on the PCBA (printed circuit board with components installed). For example, it is necessary to design a dedicated installation area in the electronic product, which is not conducive to integrated design and compression of the device volume. Utility Model Content

[0004] Based on this, the utility model provides a common mode inductor, which adopts three groups of enameled wire windings to respectively connect the live wire, the neutral wire, and the ground wire, thereby improving the margin between the amount of EMC conduction and radiation and the standard value, achieving the purpose of miniaturized design, and can be directly installed on the PCBA.

[0005] A common mode inductor, comprising:

[0006] Base plate;

[0007] A magnetic ring installed on the bottom plate; the magnetic ring is perpendicular to the bottom plate;

[0008] A first wire is wound around the magnetic ring; the first wire is evenly wound around the magnetic ring to form a first winding; and two ends of the first wire are respectively inserted into the bottom plate;

[0009] A second wire is wound around the magnetic ring; the second wire is evenly wound around the magnetic ring to form a second winding; and both ends of the second wire are respectively inserted into the bottom plate; and

[0010] A third wire is wound around the magnetic ring; the third wire is evenly wound around the magnetic ring to form a third winding; and both ends of the third wire are respectively inserted into the bottom plate; the first winding, the second winding, and the third winding are evenly spaced and distributed in sequence along the circumference of the magnetic ring; the first wire, the second wire, and the third wire are all enameled wires; the first wire, the second wire, and the third wire are respectively selected and non-repeatedly connected to the live wire, the neutral wire, and the ground wire.

[0011] In the above-mentioned common-mode inductor, the first conductor, the second conductor, and the third conductor are all enameled wires and are evenly wound on the magnetic ring to form the first winding, the second winding, and the third winding respectively. At the same time, the first winding, the second winding, and the third winding are arranged in sequence. This common-mode design not only meets the requirements of safety distance and insulation, but also each conductor adopts enameled wire with a small wire diameter, and the live wire, the neutral wire, and the ground wire are connected one by one and not repeatedly. Therefore, a magnetic ring with a smaller diameter can be used, thereby reducing the overall volume of the common-mode inductor, so that the common-mode inductor can be directly installed on the PCBA, without designing a dedicated installation area in the electronic product, which is conducive to integrated design and compression of the volume of the device. Through the above-mentioned design, three groups of enameled wire windings arranged in sequence and evenly spaced are used to connect the live wire, the neutral wire, and the ground wire respectively, so as to increase the margin between the amount of EMC conduction and radiation and the standard value, achieve the purpose of miniaturized design, and can be directly installed on the PCBA.

[0012] In one embodiment, both ends of the first wire, both ends of the second wire, and both ends of the third wire are all covered with insulating sleeves. The insulating sleeves are used to physically isolate the two ends of each wire to improve insulation safety.

[0013] In one embodiment, the insulating sleeve is a Teflon sleeve, which has the advantages of low price, high temperature resistance, corrosion resistance, high insulation, and good mechanical strength.

[0014] In one embodiment, the spacing distance between the first winding, the second winding, and the third winding is greater than 4 mm. The spacing distance between each winding is greater than 4 mm to meet the safety insulation requirements.

[0015] In one embodiment, the common mode inductor further comprises: a plurality of cable ties wound around the magnetic ring; the cable ties are insulating tapes; at least one cable tie is wound in each isolation region between the first winding, the second winding, and the third winding. The insulating cable ties can form significant and reliable physical isolation between two adjacent windings, with low cost and good isolation effect.

[0016] In one embodiment, six pins are arranged in an array on the bottom plate; the pins are connected to two ends of the first wire, two ends of the second wire, and two ends of the third wire in a one-to-one correspondence; the longitudinal distance and the lateral distance between two adjacent pins are both greater than 3 mm. The distance between two adjacent pins greater than 3 mm can meet the safety and security requirements.

[0017] In one embodiment, the longitudinal distance and the lateral distance between two adjacent pins are both greater than 7 mm. The distance between two adjacent pins is increased to further improve safety.

[0018] In one embodiment, the common mode inductor further includes: a fixing block connected between the magnetic ring and the bottom plate; the fixing block is an insulating colloid solidified at the connection between the magnetic ring and the base. The fixing block can be formed between the magnetic ring and the bottom plate by dripping glue, the bottom of the magnetic ring is coated and fixed, and an insulating isolation area is formed at both ends of each wire, which is low in cost and high in reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A front view of a common mode inductor according to an embodiment of the utility model;

[0020] Figure 2 for Figure 1 Bottom view of the base plate in the common-mode choke shown.

[0021] The meanings of the symbols in the accompanying drawings are:

[0022] 100-common mode inductor;

[0023] 10- bottom plate;

[0024] 20-magnetic ring;

[0025] 30- first conductor;

[0026] 40- second conductor;

[0027] 50-third conductor;

[0028] 60-cable tie;

[0029] 70-insulating sleeve;

[0030] 80-Fixed block. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0036] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0037] like Figure 1 and Figure 2 As shown, it is a common-mode inductor 100 according to an embodiment of the present invention.

[0038] like Figure 1 As shown, the common mode inductor 100 includes: a base plate 10, a magnetic ring 20 mounted on the base plate 10, a first wire 30 wound on the magnetic ring 20, a second wire 40 wound on the magnetic ring 20, and a third wire 50 wound on the magnetic ring 20. The base plate 10 is used to fix the magnetic ring 20 and is used as a base. The magnetic ring 20, the first wire 30, the second wire 40, and the third wire 50 together constitute a common mode choke structure. When it is used in PCBA, especially in a power module, it can filter common mode electromagnetic interference signals and play a role in EMI filtering, thereby suppressing the electromagnetic waves generated by high-speed signal lines from radiating outward.

[0039] Below, combined Figure 1 and Figure 2 , the common-mode inductor 100 mentioned above is further explained.

[0040] like Figure 1 and Figure 2 As shown, in this embodiment, the bottom plate 10 is a flat insulating plate body. When installed to the PCBA, the bottom plate 10 can be attached to the PCBA.

[0041] like Figure 1 As shown, the magnetic ring 20 is perpendicular to the bottom plate 10 , that is, the plane where the magnetic ring 20 is located is perpendicular to the plane where the bottom plate 10 is located.

[0042] like Figure 1 As shown, the first wire 30 is evenly wound around the magnetic ring 20 to form a first winding, and both ends of the first wire 30 are respectively inserted into the bottom plate 10. Figure 1 As shown, the second wire 40 is evenly wound around the magnetic ring 20 to form a second winding, and both ends of the second wire 40 are respectively inserted into the bottom plate 10. Figure 1 As shown, the third wire 50 is evenly wound around the magnetic ring 20 to form a third winding, and two ends of the third wire 50 are respectively inserted into the bottom plate 10.

[0043] The first winding, the second winding, and the third winding are evenly spaced and distributed in sequence along the circumference of the magnetic ring 20. The first wire 30, the second wire 40, and the third wire 50 are all enameled wires. The first wire 30, the second wire 40, and the third wire 50 are respectively connected to the live wire, the neutral wire, and the ground wire one by one and without duplication.

[0044] For example, Figure 1 and Figure 2 As shown, in this embodiment, both ends of the first wire 30 are connected to the live wire (L), both ends of the second wire 40 are connected to the neutral wire (N), and both ends of the third wire 50 are connected to the ground wire (G). It should be noted that the corresponding connection method between the first wire 30, the second wire 40, and the third wire 50 and the live wire (L), the neutral wire (N), and the ground wire (G) is not limited to the above order. For example, both ends of the first wire 30 can be connected to the neutral wire (N), both ends of the second wire 40 can be connected to the ground wire (G), and both ends of the third wire 50 can be connected to the live wire (L), or they can be switched.

[0045] In order to facilitate the connection between the common mode inductor 100 and the PCBA, in this embodiment, six pins distributed in an array are provided on the base plate 10. The pins are connected to the two ends of the first wire 30, the two ends of the second wire 40, and the two ends of the third wire 50 in a one-to-one correspondence. The longitudinal distance and the lateral distance between two adjacent pins are both greater than 3 mm. The distance between two adjacent pins greater than 3 mm can meet the requirements of safety regulations.

[0046] In order to further improve insulation safety, various improvements may be made to the common mode inductor 100 .

[0047] First, increase the isolation distance between two adjacent windings. Figure 1 As shown, in this embodiment, the spacing distance between the first winding, the second winding, and the third winding is greater than 4 mm. The spacing distance between each winding is greater than 4 mm to meet the safety insulation requirements.

[0048] Second: Reliable physical isolation between two adjacent windings. Figure 1 As shown, in this embodiment, the common mode inductor 100 further includes: a plurality of tie bands 60 wound around the magnetic ring 20. The tie bands 60 are insulating tapes. At least one tie band 60 is wound in each isolation area between the first winding, the second winding, and the third winding. The insulating tie bands 60 can form significant and reliable physical isolation between two adjacent windings, with low cost and good isolation effect. For example, Figure 1 As shown, a tie 60 is wound around the isolation area between the first winding and the second winding, and a tie 60 is also wound around the isolation area between the second winding and the third winding.

[0049] Third: further increase the distance between two adjacent pins. For example, the longitudinal distance and the lateral distance between two adjacent pins are both greater than 7 mm. Increasing the distance between two adjacent pins further improves safety.

[0050] For example, Figure 1 and Figure 2 As shown, six pins are provided on the base plate 10, corresponding to Figure 1 and Figure 2 Pin L1, pin L2, pin N1, pin N2, pin G1, and pin G2 in the figure. Among them, the top of pin L1 and the top of pin L2 are respectively connected to the two ends of the first wire 30, and the bottom of pin L1 and the bottom of pin L2 are respectively connected to the live wire. The top of pin N1 and the top of pin N2 are respectively connected to the two ends of the second wire 40, and the bottom of pin N1 and the bottom of pin N2 are respectively connected to the neutral wire (N). The top of pin G1 and the top of pin G2 are respectively connected to the two ends of the third wire 50, and the bottom of pin G1 and the bottom of pin G2 are respectively connected to the ground wire. At the same time, the lateral distance D1 between two adjacent pins is greater than 3mm, and the longitudinal distance D2 between two adjacent pins is greater than 3mm. It should be noted here that the longitudinal and transverse spacing distances between two adjacent pins are not required to be consistent. For example, the lateral distance D1 can be 7±0.5mm, and the longitudinal distance D2 can be 13±0.5mm.

[0051] Fourth: Set up physical isolation at both ends of each wire. For example, Figure 1 As shown, in this embodiment, both ends of the first wire 30, both ends of the second wire 40, and both ends of the third wire 50 are sleeved with insulating sleeves 70. The insulating sleeves 70 are used to physically isolate the two ends of each wire to improve insulation safety.

[0052] Furthermore, the insulating sleeve 70 may be a Teflon sleeve, which has the advantages of low price, high temperature resistance, corrosion resistance, high insulation, and good mechanical strength.

[0053] In this solution, there are many specific ways to connect the magnetic ring 20 and the base plate 10.

[0054] For example, taking glue fixing connection as an example, Figure 1 As shown, in this embodiment, the common mode inductor 100 further includes: a fixed block connected between the magnetic ring 20 and the base plate 10. The fixed block is an insulating colloid solidified at the connection between the magnetic ring 20 and the base. The fixed block can be formed between the magnetic ring 20 and the base plate 10 by dripping glue, the bottom of the magnetic ring 20 is coated and fixed, and an insulating isolation area is formed at both ends of each wire, which is low in cost and high in reliability.

[0055] For another example, in other embodiments, the base plate 10 may also be provided with a clamping structure for clamping the magnetic ring 20 , such as a clamping groove or a clamping block.

[0056] For another example, in other implementations, the magnetic ring 20 and the base plate 10 may be fixed together by other additional fixing members, such as insulating clamps or binding bands.

[0057] Brief description of working principle:

[0058] like Figure 1 As shown, the first wire 30, the second wire 40, and the third wire 50 are all enameled wires and are evenly wound on the magnetic ring 20 to form the first winding, the second winding, and the third winding respectively. At the same time, the first winding, the second winding, and the third winding are arranged in sequence. This common mode design not only meets the requirements of safety distance and insulation, but also each wire is made of enameled wire with a small wire diameter, and the live wire, the neutral wire, and the ground wire are connected one by one and not repeatedly. Therefore, a magnetic ring 20 with a smaller diameter can be used, thereby reducing the overall volume of the common mode inductor 100, so that the common mode inductor 100 can be directly installed on the PCBA, without the need to design a dedicated installation area in the electronic product, which is conducive to integrated design and compression of the volume of the device.

[0059] The common mode inductor 100 uses three groups of enameled wire windings that are evenly spaced in sequence to respectively connect the live wire, the neutral wire, and the ground wire, thereby increasing the margin between the EMC conduction and radiation and the standard value, achieving the purpose of miniaturized design, and can be directly installed on the PCBA.

[0060] In addition, the common-mode inductor 100 has a simple structure, low processing difficulty, and low cost, and can effectively suppress interference from the live wire, the neutral wire, and the ground wire.

[0061] The common mode inductor 100 can be applied to various electronic devices, especially common household appliances, such as an electromagnetic heating milk frother.

[0062] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The above embodiments only express the preferred implementation of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A common mode inductor, characterized in that: include: Base plate; A magnetic ring mounted on the bottom plate; The magnetic ring is perpendicular to the bottom plate; A first conductive wire wound around the magnetic ring; The first wire is evenly wound around the magnetic ring to form a first winding; and two ends of the first wire are respectively inserted into the bottom plate; A second wire wound around the magnetic ring; the second wire is evenly wound around the magnetic ring to form a second winding; and two ends of the second wire respectively penetrate into the bottom plate; as well as A third wire is wound around the magnetic ring; the third wire is evenly wound around the magnetic ring to form a third winding; and both ends of the third wire are respectively inserted into the bottom plate; the first winding, the second winding, and the third winding are evenly spaced and distributed in sequence along the circumference of the magnetic ring; the first wire, the second wire, and the third wire are all enameled wires; the first wire, the second wire, and the third wire are respectively and non-repeatedly connected to a live wire, a neutral wire, and a ground wire.

2. The common mode inductor according to claim 1, characterized in that: Both ends of the first wire, both ends of the second wire, and both ends of the third wire are all sleeved with insulating sleeves.

3. The common mode inductor according to claim 2, characterized in that: The insulating sleeve is a Teflon sleeve.

4. The common mode inductor according to claim 1, characterized in that: The spacing distance between the first winding, the second winding, and the third winding is greater than 4 mm.

5. The common mode inductor according to claim 1, characterized in that: Also includes: A plurality of straps are wound around the magnetic ring; the straps are insulating straps; at least one strap is wound around each isolation region between the first winding, the second winding, and the third winding.

6. The common mode inductor according to claim 1, characterized in that: The bottom plate is provided with six pins distributed in an array; the pins are connected to the two ends of the first wire, the two ends of the second wire, and the two ends of the third wire respectively in a one-to-one correspondence; the longitudinal distance and the lateral distance between two adjacent pins are both greater than 3mm.

7. The common mode inductor according to claim 6, characterized in that: The longitudinal distance and the lateral distance between two adjacent pins are both greater than 7 mm.

8. The common mode inductor according to any one of claims 1 to 7, characterized in that: Also includes: A fixing block connected between the magnetic ring and the bottom plate; the fixing block is an insulating colloid solidified at the connection between the magnetic ring and the bottom plate.

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