CN218730329U - Transformer and switching power supply circuit - Google Patents

Abstract

The utility model discloses a transformer and a switch power supply circuit, wherein the transformer comprises a framework winding slot, a shielding winding, a primary winding, an auxiliary winding and a secondary winding, wherein a magnetic core is arranged inside the framework winding slot; the shielding winding, the primary winding, the auxiliary winding and the secondary winding are sequentially wound on the framework winding slot from inside to outside. According to the technical scheme, the shielding winding is arranged on the innermost layer, the primary winding is arranged on the periphery of the shielding winding, the auxiliary winding is arranged on the periphery of the primary winding, and the secondary winding is arranged on the outermost layer, so that the coupling capacitance between the primary winding and the secondary winding can be reduced, the common-mode current between the primary winding and the secondary winding is further reduced, and the EMI (electro-magnetic interference) conduction performance of the transformer is improved.

Description

Transformer and switching power supply circuit

technical field

The utility model relates to the technical field of electronic information, in particular to a transformer and a switching power supply circuit.

Background technique

A switching power supply refers to a switching mode power supply (Switch Mode Power Supply, referred to as SMPS), also known as a switching power supply or a switching converter. It is a high-frequency power conversion device and a type of power supply. Its function is to convert a level of voltage into the voltage or current required by the user through different forms of architecture.

The transformer in the existing switching power supply circuit generally includes primary winding, secondary winding and auxiliary winding, and adopts "sandwich winding" winding, such as primary winding with secondary winding or secondary winding with primary winding, which can increase the transformer's The effective coupling area between the primary winding and the secondary winding reduces the leakage inductance of the transformer and improves the overall efficiency of the power supply. However, since the effective coupling area between the primary winding and the secondary winding is increased, the coupling capacitance between the primary winding and the secondary winding is increased, which deteriorates the conduction EMI (Electromagnetic Interference, electromagnetic interference) performance of the transformer . In the prior art, in order to solve the problem of poor conduction EMI performance of the transformer, a Y capacitor is usually added to the switching power supply circuit to reduce electromagnetic interference, but the increase of the Y capacitor occupies the space of the PCB board or the whole machine, and increases the The design cost is increased, and at the same time, the Y capacitor may cause leakage current and bring noise to the system. Therefore, there is an urgent need for a transformer that can improve the conduction EMI performance.

Utility model content

The embodiment of the utility model provides a transformer and a switching power supply circuit to solve the problem of poor conduction EMI performance of the existing transformer.

A transformer, including a skeleton winding slot with a magnetic core inside, a shielding winding, a primary winding, an auxiliary winding, and a secondary winding; the shielding winding, the primary winding, the auxiliary winding, and the secondary winding are sequentially wound from the inside to the outside Manufactured on the winding groove of the skeleton.

Further, the shielding windings are evenly arranged on the winding slots of the skeleton.

Further, the number of layers of the shielding winding is 1 layer.

Further, the skeleton winding slot includes a primary side and a secondary side, the primary side is provided with a first pin and a second pin, and the secondary side is provided with a third pin and a fourth pin;

The starting end and the ending end of the primary winding are respectively connected to the first pin and the second pin of the winding slot of the skeleton;

The starting end and the ending end of the secondary winding are respectively connected to the third pin and the fourth pin of the bobbin winding slot.

Further, the shielding winding includes at least two first winding wires;

At least two of the first winding wires are wound on the skeleton winding groove, the starting end of each of the first winding wires is connected to the fifth pin on the skeleton winding groove, each of the The end end of the first winding is suspended in the air.

Further, the number of layers of the auxiliary winding is 1 layer.

Further, the auxiliary winding includes at least two second winding wires; at least two of the second winding wires are wound on the winding slot of the skeleton, and the starting end of each second winding wire is connected to the The sixth pin on the winding slot of the skeleton is connected, and the end end of each second winding is connected with the seventh pin on the winding slot of the skeleton.

Further, the winding directions of the shielding winding, the primary winding, the auxiliary winding and the secondary winding are the same.

Further, an insulating layer is provided on the outside of the shielding winding, the primary winding, the auxiliary winding and the secondary winding.

A switching power supply circuit includes the above-mentioned transformer.

The above-mentioned transformer and switching power supply circuit, by arranging the shielding winding at the innermost layer, arranging the primary winding at the periphery of the shielding winding, arranging the auxiliary winding at the periphery of the primary winding, and arranging the secondary winding at the outermost layer, can Reduce the coupling capacitance between the primary winding and the secondary winding, thereby reducing the common mode current between the primary winding and the secondary winding, thereby improving the conducted EMI performance of the transformer.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments of the utility model. Obviously, the accompanying drawings in the following description are only the illustrations of the utility model. For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings without paying creative efforts.

Fig. 1 is a structural sectional view of a transformer in an embodiment of the present invention.

In the figure: 10, skeleton winding groove; 11, primary side; 12, secondary side; 20, shielding winding; 30, primary winding; 40, auxiliary winding; 50, secondary winding.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. . Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

It should be understood that the invention can be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity, and like reference numerals designate like elements throughout.

It will be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to" or "coupled to" another element or layer, it can be directly on, on, or "coupled to" the other element or layer. Other elements or layers may be adjacent to, connected to or coupled to, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third etc. may be used to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatial terms such as "below", "under", "beneath", "below", "above", "above", etc., may be used herein for convenience of description The relationship of one element or feature to other elements or features shown in the figures is thus described. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements or features described as "below" or "beneath" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary terms "below" and "beneath" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and not as limitations of the present invention. As used herein, the singular forms "a", "an" and "the/the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It should also be understood that the terms "consists of" and/or "comprising", when used in this specification, identify the presence of stated features, integers, steps, operations, elements and/or parts, but do not exclude one or more other Presence or addition of features, integers, steps, operations, elements, parts and/or groups. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In order to thoroughly understand the utility model, the detailed structure and steps will be provided in the following description, so as to explain the technical solution proposed by the utility model. The preferred embodiments of the utility model are described in detail as follows, but in addition to these detailed descriptions, the utility model can also have other implementations.

This embodiment provides a transformer, as shown in Figure 1, including a skeleton winding slot 10 with a magnetic core inside, a shielding winding 20, a primary winding 30, an auxiliary winding 40 and a secondary winding 50; the shielding winding 20, The primary winding 30 , auxiliary winding 40 and secondary winding 50 are sequentially wound on the skeleton winding slot 10 from inside to outside.

As an example, the transformer includes a bobbin winding slot 10 and a magnetic core. The magnetic core is installed in the winding slot 10 of the skeleton. The magnetic core is generally used to increase the magnetic induction of the electromagnet.

In this embodiment, the shielding winding 20 is arranged in the innermost layer to shield the interference signal from overflowing into the space to cause radiation interference, the primary winding 30 is arranged on the periphery of the shielding winding 20, and the auxiliary winding 40 is arranged on the primary winding 30 The periphery of the secondary winding 50 is arranged on the outermost layer. Due to the coupling capacitance between the primary winding 30 and the secondary winding 50, two kinds of positive and negative common mode currents will be generated. By arranging the auxiliary winding 40 between the primary winding 30 and the Between the secondary windings 50, at least part of the positive and negative common-mode currents can be offset, thereby reducing the common-mode current between the primary winding 30 and the secondary winding 50, thereby improving the conducted EMI performance of the transformer.

In an embodiment, the shielding windings 20 are uniformly arranged on the winding slot 10 of the skeleton.

In this embodiment, by evenly arranging the shielding windings 20 on the skeleton winding slot 10, it is ensured that the current transmitted on the shielding windings 20 is more uniform, and unnecessary common mode currents are prevented, thereby improving the performance of the transformer. Conducted EMI performance.

In an embodiment, the number of layers of the shielding winding 20 is one layer.

In this embodiment, the number of layers of the shielding winding 20 is configured as one layer to reduce the number of turns of the winding in the shielding winding 20, so as to reduce the coupling capacitance between the primary winding 30 and the secondary winding 50, thereby reducing The common mode current between the primary winding 30 and the secondary winding 50 improves the conducted EMI performance of the transformer.

In one embodiment, the skeleton winding groove 10 includes a primary side 11 and a secondary side 12, the primary side 11 is provided with a first pin PIN1 and a second pin PIN2, and the secondary side 12 is provided with The third pin PIN3 and the fourth pin PIN4; the starting end and the ending end of the primary winding 30 are respectively connected to the first pin PIN1 and the second pin PIN2 of the skeleton winding groove 10; the secondary The starting end and the ending end of the winding 50 are respectively connected to the third pin PIN3 and the fourth pin PIN4 of the bobbin winding slot 10 .

As an example, a primary side 11 and a secondary side 12 are provided on both sides of the bobbin winding groove 10 , and the primary side 11 is provided with a first pin PIN1 and a pin for connecting the primary winding 30 . The secondary side 12 is provided with a third pin PIN3 and a fourth pin PIN4 for connecting to the secondary winding 50 .

As an example, the starting end and the ending end of the primary winding 30 are respectively connected to the first pin PIN1 and the second pin PIN2 of the bobbin winding slot 10 . In this example, specific parameters of the primary winding 30 , such as winding material, number of turns and number of layers, can be set according to transformer parameters, for example, the number of layers of the primary winding 30 can be three layers.

As an example, the start end and end end of the secondary winding 50 are respectively connected to the third pin PIN3 and the fourth pin PIN4 of the bobbin winding slot 10 . In this example, specific parameters of the secondary winding 50, such as winding material, number of turns and number of layers, can be set according to transformer parameters, for example, the number of layers of the secondary winding 50 can be one layer. Further, the secondary winding 50 can be wound by a single wire, or by winding multiple wires in parallel, such as bifilar winding, depending on the required number of output groups, for example, when only one For group output, a single-wire winding can be used, and the start and end of the single-wire are used as a group of output ports; when two sets of output are required, a double-wire parallel winding structure can be used, and the start end of one of the double-wire windings and the end end as a set of output ports, and the start end and output end of the other winding as another set of output ports.

In one embodiment, the shielding winding 20 includes at least two first winding wires; at least two of the first winding wires are wound on the skeleton winding slot 10, and each of the first winding wires The starting end is connected to the fifth pin PIN5 on the winding slot 10 of the skeleton, and the ending end of each first winding is suspended.

Wherein, floating refers to no electrical connection. In this example, the hang-wire transformer at the end end of each first winding can be connected to the NC pin to ensure the stability and reliability of the transformer. Exemplarily, the NC pin can be arranged on the primary side 11 of the bobbin winding groove 10 .

As an example, at least two of the first windings are wound together on the skeleton winding slot 10, and the starting end of each of the first windings is connected to the fifth lead on the skeleton winding slot 10. The pin PIN5 is connected, and the end of each first winding wire is suspended. In this example, by winding at least two first windings together on the skeleton winding slot 10 , the starting end of each first winding is connected to the first winding on the skeleton winding slot 10 . The five pins are connected to PIN5, that is, the shielding winding 20 is wound on the skeleton winding slot 10 in parallel winding, so that the number of layers of the shielding winding 20 is 1 layer, and at the same time, the number of layers of the first winding in the shielding winding 20 is reduced. The number of turns of the wire reduces the coupling capacitance between the primary winding 30 and the secondary winding 50, thereby reducing the common mode current between the primary winding 30 and the secondary winding 50, thereby improving the conducted EMI performance of the transformer.

In one embodiment, the number of layers of the auxiliary winding 40 is one layer.

In this embodiment, the number of layers of the auxiliary winding 40 is configured as one layer to reduce the number of turns of the winding in the auxiliary winding 40, so as to reduce the coupling capacitance between the primary winding 30 and the secondary winding 50, thereby reducing The common mode current between the primary winding 30 and the secondary winding 50 improves the conducted EMI performance of the transformer.

In one embodiment, the auxiliary winding 40 includes at least two second winding wires; at least two of the second winding wires are wound on the skeleton winding slot 10, each of the second winding wires The starting end is connected to the sixth pin PIN6 on the winding slot 10 of the skeleton, and the ending end of each second winding is connected to the seventh pin PIN7 on the winding slot 10 of the skeleton.

As an example, at least two of the second windings are wound on the skeleton winding slot 10, and the starting end of each second winding is connected to the sixth lead on the skeleton winding slot 10. The pin PIN6 is connected, and the end end of each second winding is connected with the seventh pin PIN7 on the winding groove 10 of the skeleton. In this example, at least two of the second winding wires are wound on the skeleton winding groove 10, and the starting end of each second winding wire is connected to the sixth winding wire on the skeleton winding groove 10. The pin PIN6 is connected, and the end end of each second winding is connected with the seventh pin PIN7 on the winding slot 10 of the skeleton, that is, the auxiliary winding 40 is wound on the winding of the skeleton by parallel winding. On the wire slot 10, in order to meet the requirement that the number of layers of the auxiliary winding 40 is one layer, reduce the number of turns of the second winding in the auxiliary winding 40, thereby reducing the coupling capacitance between the primary winding 30 and the secondary winding 50, and then The common mode current between the primary winding 30 and the secondary winding 50 is reduced, thereby improving the conducted EMI performance of the transformer.

In one embodiment, the winding directions of the shielding winding 20 , the primary winding 30 , the auxiliary winding 40 and the secondary winding 50 are the same.

In this embodiment, the winding directions of the shielding winding 20, the primary winding 30, the auxiliary winding 40 and the secondary winding 50 are the same, which reduces the complexity of the transformer production process and facilitates the improvement of the shielding winding 20, the primary winding 20, and the secondary winding 50. Winding 30, the auxiliary winding 40 and the secondary winding 50 have winding efficiencies.

In an embodiment, the outer surfaces of the shielding winding 20 , the primary winding 30 , the auxiliary winding 40 and the secondary winding 50 are all provided with insulating layers.

Wherein, the insulating layer includes but not limited to polyamide film, insulating spray paint coating or glass fiber layer.

In this embodiment, an insulating layer is provided outside the shielding winding 20, the primary winding 30, the auxiliary winding 40 and the secondary winding 50, so that the shielding winding 20, the primary winding 30, and the Both the auxiliary winding 40 and the secondary winding 50 can withstand high AC voltage, which improves safety.

This embodiment provides a switching power supply circuit, including the above-mentioned transformer.

In this embodiment, since the switching power supply circuit includes the transformer in the above embodiment, the transformer has better conduction EMI performance, therefore, there is no need to add a Y capacitor in the switching power supply circuit to reduce electromagnetic interference and reduce design costs , while avoiding the leakage current caused by the Y capacitor, and improving the overall performance of the switching power supply circuit.

The above-described embodiments are only used to illustrate the technical solutions of the present utility model, and are not intended to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still understand the foregoing The technical solutions recorded in each embodiment are modified, or some of the technical features are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present utility model, and all Should be included in the scope of protection of the present utility model.

Claims (10)

1. A transformer is characterized by comprising a framework winding slot, a shielding winding, a primary winding, an auxiliary winding and a secondary winding, wherein a magnetic core is arranged in the framework winding slot; the shielding winding, the primary winding, the auxiliary winding and the secondary winding are sequentially wound on the framework winding slot from inside to outside.

2. The transformer of claim 1, wherein the shield windings are evenly arranged on the bobbin winding slots.

3. The transformer of claim 2, wherein the number of layers of the shield winding is 1.

4. The transformer of claim 1, wherein the bobbin winding slot comprises a primary side and a secondary side, the primary side being provided with a first pin and a second pin, the secondary side being provided with a third pin and a fourth pin;

the starting end and the ending end of the primary winding are respectively connected to the first pin and the second pin of the framework winding slot;

and the starting end and the ending end of the secondary winding are respectively connected to the third pin and the fourth pin of the framework winding slot.

5. The transformer of claim 4, wherein the shield winding comprises at least two first windings;

at least two first windings wind around on skeleton wire winding groove, every the initiating terminal of first winding links to each other with the fifth pin on the skeleton wire winding groove, every the end of first winding is unsettled.

6. The transformer of claim 1, wherein the number of layers of the auxiliary winding is 1.

7. The transformer of claim 6, wherein the auxiliary winding comprises at least two second windings; and at least two second windings are wound on the framework winding groove, the starting end of each second winding is connected with a sixth pin on the framework winding groove, and the finishing end of each second winding is connected with a seventh pin on the framework winding groove.

8. The transformer of claim 1, wherein the shield winding, the primary winding, the auxiliary winding, and the secondary winding are wound in the same direction.

9. The transformer of claim 1, wherein the shield winding, the primary winding, the auxiliary winding, and the secondary winding are provided with an insulating layer on the outside.

10. A switched-mode power supply circuit, characterized in that it comprises a transformer according to any one of claims 1-9.

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