CN220796446U - Winding structure of unshielded transformer and electronic equipment - Google Patents

Abstract

The utility model discloses a winding structure of a non-shielding transformer and electronic equipment, which comprises a primary side, a secondary side, a magnetic core and a framework, wherein the magnetic core is arranged on the framework, a primary main winding, an auxiliary winding and a secondary winding are wound on the magnetic core, and the grounding end of the auxiliary winding is connected with the magnetic core through a lead wire, so that the auxiliary winding is positioned between the primary main winding and the secondary winding to form a magnetic core shielding layer. The auxiliary windings are arranged and connected with the magnetic cores, so that the winding layer number and the winding width of the insulating adhesive tapes of each winding are controlled, two main problems of EMC electromagnetic radiation and safe leakage current in a switch power supply product can be solved simultaneously, the switch power supply product does not need a Y capacitor, and the transformer can meet the technical standard requirements of passing EMC electromagnetic radiation tests without adding an extra shielding winding design; the device is suitable for various electronic devices and metal shells, or device products which are quite sensitive to leakage current interference.

Description

Winding structure of unshielded transformer and electronic equipment

Technical Field

The utility model relates to the technical field of transformers, in particular to a winding structure of a non-shielding transformer, which can meet the requirements of EMC electromagnetic radiation test technical standards, EMI interference and transformer leakage current reduction and is wound by controlling widths and numbers of insulating tapes and secondary winding wires.

Background

Electromagnetic interference EMI (Electromagnetic Interference) has become an unavoidable radiation problem for global electronics, however, electromagnetic interference for electronics is mainly caused by the poor touch and common mode of the product itself. The common mode interference problem is relatively difficult to process, the cost of a method for suppressing common mode interference from an input is relatively high, the obtained effect of suppressing common mode interference is not obvious, and the problem needs to be solved from an interference source. A large part of common mode interference noise of the switching power supply is derived from unreasonable design of the transformer and high-frequency noise dv/dt signals of the primary inside the transformer are coupled to the secondary through parasitic capacitance, and then coupled to an EMI conduction receiving test instrument through parasitic capacitance of a secondary winding and the ground (PGND), or radiated to a radio frequency receiving instrument through input and output wires of a switching power supply product. Therefore, how to reduce the interference of the common mode differential mode generated by the transformer by improving the structure of the transformer so as to effectively reduce the interference problem of the amplitude of the common mode interference noise dv/dt to the switching power supply product has become one direction for developing the transformer.

Disclosure of Invention

In order to solve the technical problems, the utility model provides a winding structure of a non-shielding transformer and electronic equipment.

In order to solve the technical problems, the utility model adopts the following technical scheme:

the winding structure of the unshielded transformer comprises a primary side, a secondary side, a magnetic core and a framework, wherein the magnetic core is arranged on the framework, a primary main winding, an auxiliary winding and a secondary winding are wound on the magnetic core, and the grounding end of the auxiliary winding is connected with the magnetic core through a lead wire, so that the auxiliary winding is positioned between the primary main winding and the secondary winding to form a magnetic core shielding layer.

The layers of the insulating tapes wound on the primary main winding, the auxiliary winding and the secondary winding are different.

And two layers of insulating adhesive tapes are arranged on the primary main winding.

And a layer of insulating adhesive tape is wound on the auxiliary winding.

And three layers of insulating tapes are arranged on the secondary winding.

The primary side is provided with a first pin, a second pin, a fourth pin and a fifth pin, the secondary side is provided with a sixth pin and a seventh pin, the primary main winding starts to wind from the fourth pin to wind from the first pin, the auxiliary winding starts to wind from the fifth pin to wind from the second pin, and the secondary winding starts to wind from the seventh pin to wind from the sixth pin.

And in the framework, sequentially winding the secondary winding, the auxiliary winding and the primary main winding from top to bottom.

The winding widths of the primary main winding, the auxiliary winding and the secondary winding are the same or different.

The winding width of the secondary winding is smaller than the winding widths of the primary main winding and the auxiliary winding.

An electronic device, which is applied to the winding structure of the unshielded transformer.

According to the utility model, the auxiliary winding is additionally arranged, and the number of winding layers of the insulating tapes of the primary winding, the auxiliary winding and the secondary winding is controlled, so that two main problems of EMC electromagnetic radiation and safe leakage current in a switch power supply product can be solved at the same time, the fact that a Y capacitor is not required for the switch power supply product is realized, and the transformer can meet the technical standard requirements of passing EMC electromagnetic radiation test without additionally arranging a shielding winding; the circuit is suitable for routers, optical cat set-top boxes, WIFI wireless telephones and metal shell mobile phones, or equipment products which are quite sensitive to leakage current interference, Y capacitance and X capacitance in circuit design are removed, and meanwhile EMI electromagnetic radiation interference is reduced.

Drawings

FIG. 1 is a schematic diagram of the electrical principle of the present utility model;

FIG. 2 is a schematic view of a winding structure according to the present utility model;

FIG. 3 is a schematic side view of an auxiliary winding connection core of the present utility model;

FIG. 4 is a schematic front view of an auxiliary winding core of the present utility model;

fig. 5 is a schematic diagram of the circuit principle of the present utility model in the practical application circuit of the product.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present utility model and are not to be construed as limiting the present utility model.

In the description of the present utility model, it should be understood that if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., the indicated azimuth or positional relationship is based on the azimuth or positional relationship shown in the drawings, it is merely for convenience of description and simplification of the description, and does not indicate or imply that the indicated apparatus or element must have a specific azimuth, be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present utility model, it should be noted that the terms "mounted," "connected," and "coupled" are to be construed broadly, as well as, for example, fixedly coupled, detachably coupled, or integrally coupled, unless otherwise specifically indicated and defined. Either mechanically or electrically. Can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

As shown in fig. 1 to 5, a winding structure of a non-shielding transformer includes a primary side and a secondary side, and a core and a bobbin, the core is mounted on the bobbin, a primary main winding, an auxiliary winding and a secondary winding are wound on the core, and a ground terminal of the auxiliary winding is connected to the core through a lead wire, so that the auxiliary winding is located between the primary main winding and the secondary winding, and a core shielding layer is formed, by which EMI electromagnetic radiation interference can be reduced. A separate Y capacitor and an X capacitor for resisting interference are not required to be arranged.

The number of layers of the insulating tapes wound on the primary main winding, the auxiliary winding and the secondary winding is different, frameworks with different widths can be met through setting of the insulating tapes with different layers, applicability is improved, and the conductive radiation test requirements of products are met through the different layers of the insulating tapes.

Specifically, two layers of insulating tapes are arranged on the primary main winding. And a layer of insulating adhesive tape is wound on the auxiliary winding. And three layers of insulating tapes are arranged on the secondary winding.

In addition, the winding widths of the primary main winding, the auxiliary winding and the secondary winding are the same or different.

The capacitance coupling of common mode noise between the primary and the secondary is fundamentally reduced through the control of the winding layer number of the insulating adhesive tapes of each winding and the winding width.

The Y capacitor crossing the primary high-voltage end and the secondary low-voltage end is not selected to reduce the electromagnetic radiation of the transformer, so that the assembled product cannot generate dangerous electric leakage phenomenon. The grounding end lead of the auxiliary winding is connected with the magnetic core, and the winding width of the secondary winding is controlled to reduce the interlayer effective capacitance capacity of the transformer, so that the common-mode interference current of the primary main group coupled to the secondary winding is reduced, and the problem of EMC electromagnetic radiation of a product is solved by the design of the transformer.

Referring to fig. 1, taking a transformer as an example, the primary side has a first pin 1, a second pin 2, a fourth pin 4 and a fifth pin 5, the secondary side has a sixth pin 6 and a seventh pin 7, the primary main winding N1 starts winding with the fourth pin 4 as a starting winding end, the winding ends at the first pin 1, and a layer of 2 insulating tape is wound; the auxiliary winding N2 starts winding by taking the fifth pin 5 as an initial winding end, and finishes winding at the second pin 2, and winds 1 layer of insulating adhesive tape; the secondary winding N3 starts winding by taking the seventh pin 4 as a starting winding end, and ends winding at the sixth pin 6, the winding width is controlled, and 3 layers of insulating adhesive tapes are wound. By the above limitation of the winding, the anti-interference effect can be achieved without the Y capacitor.

Referring to fig. 5, a common-mode current path of an equivalent capacitor of a transformer in a product practical application circuit is generated, a primary winding N1, an auxiliary winding N2 and a secondary winding N3 of the transformer are applied, the primary winding N1 and the secondary winding N3 are respectively connected, an input is connected with a MOS tube through the primary winding N1, a fourth pin of the primary winding N1 is connected with a capacitor CPM and a capacitor CPS which are connected in parallel, the other ends of the capacitor CPM and the capacitor CPS are connected with a seventh pin of the secondary winding N3 and then output and grounded, a fifth pin of the auxiliary winding N2 is connected with a power supply through a diode and is connected with the MOS tube through a capacitor, a second pin of the auxiliary winding is connected with the input, a fifth pin of the auxiliary winding N2 is connected with a capacitor cpmt and a capacitor CFA which are connected in parallel, and is grounded through a capacitor CPE, a sixth pin of the secondary winding N3 is connected with the capacitor CPE through a capacitor CUE, wherein:

a capacitor CQE flowing through the power MOSFET source to ground; generating a common mode current through CPM and CPE; generating a common mode current through the CFT and the CUE; common mode current is generated through CPS and CUE, and the transformer structure mainly plays a role in the common mode current, so that the effect of reducing the common mode current can be realized.

It should be noted that, the foregoing is only a preferred embodiment of the present utility model, and the present utility model is not limited to the foregoing embodiment, but it should be understood that although the present utility model has been described in detail with reference to the embodiment, it is possible for those skilled in the art to make modifications to the technical solutions described in the foregoing embodiment, or to make equivalent substitutions for some technical features thereof, but any modifications, equivalent substitutions, improvements and the like within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (10)

1. The winding structure of the unshielded transformer comprises a primary side, a secondary side, a magnetic core and a framework, and is characterized in that the magnetic core is arranged on the framework, a primary main winding, an auxiliary winding and a secondary winding are wound on the magnetic core, and the grounding end of the auxiliary winding is connected with the magnetic core through a lead wire, so that the auxiliary winding is positioned between the primary main winding and the secondary winding to form a magnetic core shielding layer.

2. The winding structure of the unshielded transformer according to claim 1, wherein the number of layers of the insulating tape wound on the primary main winding, the auxiliary winding and the secondary winding is different.

3. The winding structure of the unshielded transformer according to claim 1, wherein two layers of insulating tape are provided on the primary main winding.

4. The winding structure of the unshielded transformer according to claim 1, wherein a layer of insulating tape is wound on the auxiliary winding.

5. The winding structure of the unshielded transformer according to claim 1, wherein three layers of insulating tape are provided on the secondary winding.

6. The winding structure of the unshielded transformer according to claim 1, wherein the primary side has a first pin, a second pin, a fourth pin, and a fifth pin, the secondary side has a sixth pin and a seventh pin, the primary main winding starts winding from the fourth pin to the end of winding of the first pin, the auxiliary winding starts winding from the fifth pin to the end of winding of the second pin, and the secondary winding starts winding from the seventh pin to the end of winding of the sixth pin.

7. The winding structure of the unshielded transformer of claim 6, wherein the secondary winding, the auxiliary winding and the primary main winding are sequentially wound from top to bottom in the bobbin.

8. The winding structure of the unshielded transformer according to claim 1, wherein the winding widths of the primary main winding, the auxiliary winding and the secondary winding are the same or different.

9. The winding structure of the shielding-free transformer according to claim 1, wherein a winding width of the secondary winding is smaller than a winding width of the primary main winding and the auxiliary winding.

10. An electronic device characterized in that the winding structure of the unshielded transformer according to any one of claims 1 to 9 is applied.