CN113436857B

CN113436857B - Transformer, circuit substrate and switching power supply

Info

Publication number: CN113436857B
Application number: CN202110681499.7A
Authority: CN
Inventors: 陶淦; 何成军; 林文涛; 李希志; 武景涛
Original assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Current assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Priority date: 2021-06-18
Filing date: 2021-06-18
Publication date: 2023-02-28
Anticipated expiration: 2041-06-18
Also published as: CN113436857A

Abstract

The embodiment of the invention provides a transformer, a circuit substrate and a switching power supply, relates to the technical field of circuits, and can improve the stability of multi-path output voltage in an integrated switching power supply. The transformer includes: a framework; the plurality of windings are sequentially wound on the framework from inside to outside; the plurality of windings comprises a plurality of primary windings and a plurality of secondary windings; wherein one or two secondary windings are arranged between any two adjacent primary windings.

Description

Transformer, circuit substrate and switching power supply

Technical Field

The application relates to the technical field of circuits, in particular to a transformer, a circuit substrate and a switching power supply.

Background

At present, the air conditioner or the refrigerator and other electrical appliances are provided with a compressor and a fan, and in order to reduce the volume of the air conditioner or the refrigerator and other electrical appliances and improve the power supply efficiency of the compressor and the fan, the compressor and the fan are usually powered by an integrated switching power supply.

In the integrated power supply scheme, a power supply circuit of the compressor needs 8 driving power supplies, a power supply circuit of the fan needs 1 power supply, and an integrated circuit substrate and a switch power supply chip respectively need 1 power supply, so that the integrated switch power supply needs to output 11 power supplies with different powers at the same time. However, the compressor has a large power and a large current, while the fan has a small power and a small current. When the compressor works in a large load, the current is large, so that the voltage of other power supplies in the switching power supply is increased greatly, and the stability of the output voltage of the switching power supply is poor. For example, when the compressor is operated under a heavy load, the voltage of the power supply corresponding to the fan rises to 1.5 times the rated voltage, resulting in damage to the components in the circuit corresponding to the fan.

The transformer is an important component of the integrated switching power supply, and the stability of the output voltage of the transformer is directly related to the stability of the multi-path output voltage of the switching power supply, so a new transformer is urgently needed to meet the requirement of the stability of the multi-path output voltage of the integrated switching power supply.

Disclosure of Invention

The embodiment of the application provides a transformer, a circuit substrate and a switching power supply, which can improve the stability of multi-path output voltage in an integrated switching power supply.

In a first aspect, an embodiment of the present application provides a transformer, including: a framework; the plurality of windings are sequentially wound on the framework from inside to outside; the plurality of windings comprises a plurality of primary windings and a plurality of secondary windings; wherein one or two secondary windings are arranged between any two adjacent primary windings.

Compared with the technical scheme that the primary winding is wound on the framework in the inner layer and the secondary winding is wound on the outer layer, the technical scheme provided by the embodiment of the application divides the primary winding into the multiple primary windings, divides the secondary winding into the multiple secondary windings, and is provided with one or two secondary windings between any two adjacent primary windings, so that the multiple primary windings can be arranged at intervals, the multiple secondary windings can be arranged at intervals, and the distance between the primary winding and the distance between the secondary winding and the secondary winding are increased. It should be understood that the stability of the multiple output voltages during the operation of the transformer is directly related to the magnetic field intensity of the leakage flux during the operation of the transformer, and the magnetic field intensity of the leakage flux during the operation of the transformer is influenced by the interference between the windings of the transformer and is directly related to the distance between the wires of the windings. Therefore, according to the technical scheme provided by the embodiment of the application, the distance between the primary winding and the distance between the secondary winding and the secondary winding can be increased by arranging one or two secondary windings between any two adjacent primary windings, the magnetic field intensity of magnetic leakage in the working engineering of the transformer is reduced, the stability of multi-path output voltage in the working process of the transformer is improved, and the stability of the multi-path output voltage in the integrated switching power supply is improved.

In some embodiments, the innermost winding of the plurality of windings is a primary winding, and the outermost winding is a primary winding.

In some embodiments, the plurality of windings comprises: three primary windings, and two secondary windings disposed between any adjacent two primary windings.

In some embodiments, in the plurality of windings, in order from inside to outside, the windings of the odd-numbered layers are primary windings, and the windings of the even-numbered layers are secondary windings.

In some embodiments, the wire of the primary winding is enameled wire and the wire of the secondary winding is triple insulated wire.

In some embodiments, the skeleton has a core slot; the transformer further includes: and a magnetic core installed in the magnetic core groove.

In some embodiments, the structure of the magnetic core is an EE-type structure or a UU-type structure.

In some embodiments, the magnetic core comprises a first magnetic pillar and a second magnetic pillar arranged side by side; a plurality of air gaps are arranged on the first magnetic column and/or the second magnetic column; the transformer further includes: and a non-magnetic material filled in the plurality of air gaps.

In a second aspect, embodiments of the present application provide a circuit substrate. The circuit substrate comprises the transformer described in the first aspect and possible implementations.

In a third aspect, embodiments of the present application provide a switching power supply. The switching power supply includes the circuit substrate described in the second aspect above.

For the description of the second and third aspects in the present application, reference may be made to the detailed description of the first aspect; in addition, for the beneficial effects described in the second aspect and the third aspect, reference may be made to beneficial effect analysis of the first aspect, and details are not described here.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a diagram of a power supply system of an air conditioner provided in the related art;

fig. 2 is a schematic power supply diagram of a compressor power module of an air conditioner provided in the related art;

fig. 3 is a schematic diagram illustrating a winding manner of a winding of a transformer provided in the related art;

fig. 4 is a magnetic field intensity diagram of a transformer provided in the related art;

fig. 5 is a schematic structural diagram of a transformer according to an embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of a bobbin of a transformer according to an embodiment of the present disclosure;

fig. 7 is a schematic diagram illustrating a winding manner of a winding of a transformer according to an embodiment of the present application;

fig. 8 is a schematic diagram illustrating a winding manner of a winding of another transformer according to an embodiment of the present application;

fig. 9 is a schematic diagram illustrating a winding manner of a winding of another transformer according to an embodiment of the present application;

fig. 10 is a schematic winding diagram of a transformer according to an embodiment of the present application;

fig. 11 is a schematic diagram illustrating a winding manner of a winding of another transformer according to an embodiment of the present application;

fig. 12 is a schematic diagram of magnetic field strength of a transformer according to an embodiment of the present application;

fig. 13 is a schematic diagram illustrating a winding manner of a winding of another transformer according to an embodiment of the present application;

fig. 14 is a schematic view of a magnetic core of a transformer according to an embodiment of the present application;

fig. 15 is a schematic view of a magnetic core of another transformer according to an embodiment of the present application.

Detailed Description

The transformer, the circuit board, and the switching power supply provided in the embodiments of the present application are described in detail below with reference to the drawings.

The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone.

The terms "first" and "second" and the like in the description and drawings of the present application are used for distinguishing different objects or for distinguishing different processes for the same object, and are not used for describing a specific order of the objects.

Furthermore, the terms "including" and "having," and any variations thereof, as referred to in the description of the present application, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

In the description of the present application, the meaning of "a plurality" means two or more unless otherwise specified.

As shown in fig. 1, a power supply system diagram of an air conditioner is provided in the related art. In fig. 1, the control device of the air conditioner includes a rectifying and filtering circuit 01, a switching power supply 02, a control circuit 03, a compressor power module 04, and a fan driving circuit 05. The input end of the rectifying and filtering circuit 01 is connected with a power supply. The input end of the switching power supply 02 is connected with the output end of the rectifying and filtering circuit 01, and the output end of the switching power supply 02 is connected with the control circuit 03. The switching power supply 02 is used for outputting multiple power supplies, and drives the first control device 101, the second control device 102, the third control device 111, the fourth control device 112, the fifth control device 121, the sixth control device 122, and the fan driving circuit 05 in the compressor power module 04 through the control circuit 03.

In the power supply system shown in fig. 1, the driving power supply of the compressor power module 04 and the power supply of the fan driving circuit 05 are both provided by the switching power supply, so that an integrated power supply scheme is realized, and the volume of the control device of the air conditioner is reduced. As shown in fig. 2, a power supply diagram of the compressor power module 04 is shown, the first control device 101, the third control device 111, and the fifth control device 121 of the controller in the compressor power module 04 respectively require one power supply, and the second control device 102, the fourth control device 112, and the sixth control device 122 share one power supply. To achieve control of the compressor, the positive pressure 15V and the negative pressure 8V need to drive the control elements together, and therefore, the compressor power module 04 needs 8 power supplies. In the fan driving circuit 05, the current of the fan is small, and only one power supply is needed. In addition, for the integrated power supply scheme, the circuit substrate and the switching power supply chip respectively need 1 power supply. Therefore, the control device of the air conditioner requires the switching power supply to provide 11 paths of power.

However, in the operation process of the air conditioner, that is, in the operating state of the switching power supply, since the driving current of the driving device in the compressor power module 04 is generally large, the voltage of the multi-path output voltage of the switching power supply is increased, which may cause the output voltage of the switching power supply to exceed the limit voltage of the components in the circuit, thereby causing the damage of the components in the circuit. For example, the voltage of the power supply to which the fan corresponds may rise 1.5 times or more the rated voltage, causing damage to devices in the fan drive circuit 05.

As shown in fig. 1, the switching power supply 02 includes a transformer 21 and a modulation circuit 22. The transformer 21 is used for converting the input power supply into a multi-output power supply, and the modulation circuit is used for modulating the multi-output power supply. The transformer 21 is an important component of the switching power supply 02, and the stability of the output voltage of the transformer 21 is directly related to the stability of the multiple output voltages of the switching power supply 02.

As shown in table 1, a winding method of a winding of a transformer is provided in the related art. In table 1, the first primary winding P1 and the second primary winding P2 are wound on the innermost layer and the outermost layer of the bobbin, respectively. The first secondary winding S1, the second secondary winding S2, the third secondary winding S3, the fourth secondary winding S4 and the fifth secondary winding S5 are wound between the first primary winding P1 and the second primary winding P2.

TABLE 1

Winding wire	Wire rod specification	Number of turns	Starting head	Tail end	Winding method
						P1	2UEWФ0.35╳1	64	23	21	Close-wound 2 layers
S1	TEXФ0.26╳1	9	29	28	Loosely wound 1 layer
						S2	TEXФ0.6╳1	11	33	32	Loosely wound 1 layer
S3	TEXФ0.6╳1	8	36	35	Loosely wound 1 layer
						S4	TEXФ0.26╳4	9	1、6、11、16	2、7、12、17	Are wound in 1 layer
S5	TEXФ0.26╳4	5	2、7、12、17	3、8、13、18	Are wound in 1 layer
						P2	2UEWФ0.35╳1	34	21	9	Densely wound 1 layer

Based on the winding method shown in table 1, as shown in fig. 3, the first primary winding P1 is tightly wound by 2 layers and wound on the innermost layer of the bobbin. The second primary winding P2 is tightly wound by 1 layer and wound on the outermost layer of the framework. Between the primary windings P1 and P2, a first secondary winding S1, a second secondary winding S2, a third secondary winding S3, a fourth secondary winding S4, and a fifth secondary winding S5 are respectively arranged in the sequence from inside to outside wound on the bobbin.

Based on the embodiment shown in fig. 3, the magnetic field intensity of the leakage flux between the plurality of windings wound on the bobbin is shown in fig. 4. Because the first secondary winding S1, the second secondary winding S2, the third secondary winding S3, the fourth secondary winding S4 and the fifth secondary winding S5 are wound adjacently, the magnetic field strengths of the leakage magnetic fluxes of the five secondary windings are superposed in the same direction, and the absolute value of the magnetic field strengths of the leakage magnetic fluxes of the multiple windings wound on the framework is 20A/m. And the magnetic field intensity of the leakage flux of a plurality of windings wound on the framework is not zero (20A/m), which directly influences the stability of the multi-output voltage in the working process of the transformer. Therefore, the magnetic field intensity of magnetic leakage of a plurality of windings wound on the framework is reduced, and the stability of the multi-path output voltage in the working process of the transformer can be improved.

To this end, as shown in fig. 5, the present embodiment provides a transformer 30, where the transformer 30 includes: the winding comprises a framework 31 and a plurality of windings wound on the framework 31 from inside to outside in sequence; the plurality of windings comprises a plurality of primary windings and a plurality of secondary windings; wherein one or two secondary windings are arranged between any two adjacent primary windings.

The bobbin 31, also called a bobbin of the transformer 30, is an important component of the transformer 30, and is used to provide a winding space for the windings, so that the plurality of windings of the transformer 30 can be wound on the bobbin. Illustratively, as shown in fig. 6, the bobbin 31 includes a bobbin top 311, a winding portion 312 and a bobbin base 313, wherein a winding space is formed between the bobbin top 311 and the bobbin base 313, and a plurality of windings of the transformer 30 can be wound in the winding space on the winding portion 312.

Alternatively, as shown in fig. 6, the bobbin 31 has a core slot 314; the transformer 30 further includes: a core mounted in the core slot 314.

Optionally, the frame 31 may be made of a non-magnetic material and an insulating material, and for example, the material of the frame 31 may be nylon, plastic, epoxy board, glass fiber, teflon, or the like.

Alternatively, as shown in fig. 6, the bobbin 31 has a bobbin base 313 for fixing the transformer 30 to the circuit substrate. For example, the transformer 30 may be soldered to the circuit substrate through the frame base 313. For example, the transformer 30 can be soldered (e.g., soldered) to the circuit substrate by metal probes on the bobbin base 313, thereby facilitating mass production of the transformer. As another example, the transformer 30 may be plugged onto the circuit substrate through the bobbin base 313. For example, a plug-in slot is disposed on the circuit substrate, and the transformer 30 can be plugged into the plug-in slot of the circuit substrate through the metal probe of the skeleton base 313, so as to facilitate the detachment and maintenance of the transformer.

It should be noted that the primary winding, also called primary coil, and primary side winding, are connected to the power supply of the transformer, and are used for receiving the electric energy of the power supply and exciting the magnetic field of the transformer. The secondary winding, also called as a secondary coil, a secondary coil and a secondary side winding are connected with the load of the transformer and used for being influenced by the magnetic field of the transformer and providing electric energy for the load.

In some embodiments, to increase the degree of coupling between the primary and secondary windings, the primary winding may be provided as a plurality of primary windings, the secondary winding provided as a plurality of secondary windings, one or two secondary windings being provided between any two adjacent primary windings.

Illustratively, as shown in fig. 7, two primary windings 51 and one secondary winding 52 are wound on the winding portion 312 of the bobbin, wherein one secondary winding 52 is disposed between the two primary windings 51. Insulating films 53 are provided between the primary winding 51 and the secondary winding 52, respectively, for electrical isolation.

Compared with the technical scheme that the primary winding is wound on the inner layer of the framework and the secondary winding is wound on the outer layer of the framework, the technical scheme provided by the embodiment of the application divides the primary winding into the multiple primary windings, the secondary winding is divided into the multiple secondary windings, and one or two secondary windings are arranged between two adjacent primary windings in the multiple primary windings, so that the multiple primary windings can be arranged at intervals, the multiple secondary windings can also be arranged at intervals, and the distance between the primary windings and the secondary windings and the distance between the secondary windings and the secondary windings are increased. It should be understood that the stability of the multiple output voltages during the operation of the transformer is directly related to the magnetic field intensity of the leakage flux during the operation of the transformer, and the magnetic field intensity of the leakage flux during the operation of the transformer is influenced by the interference between the windings of the transformer and is directly related to the distance between the wires of the windings. Therefore, according to the technical scheme provided by the embodiment of the application, one or two secondary windings are arranged between two adjacent primary windings in the plurality of primary windings, so that the distance between the primary windings and the distance between the secondary windings and the secondary windings are increased, the magnetic field intensity of magnetic leakage in the working engineering of the transformer is reduced, the stability of multi-path output voltage in the working process of the transformer is improved, and the stability of the multi-path output voltage in the integrated switching power supply is improved.

In some embodiments, in order to improve the coupling degree between the primary winding and the secondary winding and reduce the magnetic leakage influence among the plurality of primary windings, the winding wound on the innermost layer of the framework is the primary winding, and the winding wound on the outermost layer of the framework is the primary winding. Therefore, the space between the primary windings can be increased to the maximum extent, and the interference between the primary windings is reduced.

In some embodiments, the plurality of windings comprises: three primary windings, and two secondary windings disposed between any adjacent two primary windings. Illustratively, the plurality of windings are wound on the framework in the sequence from inside to outside: the secondary winding comprises a first primary winding, a first secondary winding, a second primary winding, a third secondary winding, a fourth secondary winding and a third primary winding.

For example, the plurality of windings are wound on the bobbin in the order from the inside to the outside as shown in table 2.

TABLE 2

Based on the winding method shown in table 2, as shown in fig. 8 and fig. 9, the winding method includes, in order from inside to outside of the frame: the first primary winding is P1 tightly wound for 1 layer, the first secondary winding S1 is wound for 1 layer, the second secondary winding S2 is wound for 1 layer, the second primary winding P2 is sparsely wound for 2 layers, the third secondary winding S3 is sparsely wound for 1 layer, the fourth secondary winding S4 is wound for 1 layer, and the third primary winding P3 is tightly wound for 1 layer. A plurality of windings are wound in the winding space between the bobbin top 311 and the bobbin base 313 in the order shown in table 2.

In this way, the first secondary winding S1 and the second secondary winding S2 are disposed between the first primary winding P1 and the second primary winding P2. A third secondary winding S3 and a fourth secondary winding S4 are disposed between the second primary winding P2 and the third primary winding P3. The second primary winding P2 is loosely wound by 2 layers, so that the distance between the second secondary winding S2 and the third secondary winding S3 can be increased. Thus, the number of adjacent secondary windings in the plurality of secondary windings is reduced, the distance between the secondary windings is increased, and the magnetic field intensity of leakage flux between the plurality of secondary windings is reduced.

It should be noted that increasing the distance between windings can reduce the magnetic field intensity of the magnetic flux leakage between windings. As shown in fig. 10, when the spacing between the center lines of the adjacent winding wires is greater than 3W, that is, the spacing between the wire edges of the adjacent winding wires is greater than 2W, where W is the line width of the winding wires, the interference between the adjacent windings will be reduced by 70%.

Based on the embodiments shown in fig. 8 and 9, as shown in fig. 11, two secondary windings are disposed between the first primary winding P1 and the second primary winding P2, and the wire edge spacing is greater than 2W. Two secondary windings are arranged between the second primary winding P2 and the third primary winding P3, and the distance between the edges of the wires is larger than 2W. Two layers of primary windings are arranged between the second secondary winding S2 and the third secondary winding S3, and the edge distance of the conducting wire is larger than 2W, so that the magnetic field intensity of magnetic leakage between the windings in the plurality of windings is greatly reduced.

Based on the embodiments shown in fig. 8 and 9, as shown in fig. 12, the embodiment of the present application provides a schematic diagram of magnetic field intensity leaking between a plurality of windings of the transformer 30. The absolute value of the magnetic field intensity of the leakage flux shown in FIG. 12 is reduced from 20A/m to 10A/m, compared to the magnetic field intensity of the leakage flux shown in FIG. 4. Therefore, according to the embodiment of the application, the plurality of primary windings and the plurality of secondary windings are wound in a layered and staggered manner, the magnetic field intensity of magnetic leakage in the working process of the transformer is reduced, and the stability of multi-path output voltage in the working process of the transformer is improved.

In other embodiments, in the plurality of windings, the windings of the odd-numbered layers may be primary windings, and the windings of the even-numbered layers may be secondary windings in order from the inside to the outside.

Illustratively, as shown in fig. 13, the plurality of windings are a first primary winding P1, a first secondary winding S1, a second primary winding P2, a second secondary winding S2, a third primary winding P3, a third secondary winding S3, a fourth primary winding P4, and a fourth secondary winding S4, respectively, in the order of winding on the bobbin from inside to outside. Therefore, a secondary winding is arranged between any two adjacent primary windings, the fully-staggered windings of the plurality of primary windings and the plurality of secondary windings of the transformer are realized, the magnetic field intensity of magnetic leakage in the working process of the transformer is reduced, and the stability of multi-path output voltage in the working process of the transformer is improved.

In some embodiments, in the multiple windings, in order from inside to outside, the windings of the odd-numbered layers may also be secondary windings, and the windings of the even-numbered layers may also be primary windings, which is not limited in this respect.

In some embodiments, the wire of the primary winding is enameled wire and the wire of the secondary winding is triple insulated wire. Compared with an enameled wire, the insulating property of the triple insulated wire is better, so that the thickness of an insulating film between windings is reduced, the size of the transformer is reduced, and the coupling property of the secondary winding and the primary winding is further improved.

It can be understood that, in the above embodiments, the winding manner of the winding of the transformer is changed to reduce the magnetic field intensity of the leakage flux of the transformer, so as to improve the stability of the multiple output voltages during the operation of the transformer. In the embodiment of the application, the magnetic leakage magnetic field intensity of the transformer can be reduced by changing the magnetic core structure of the transformer.

In some embodiments, the structure of the magnetic core of the transformer may be an EE-type structure or a UU-type structure, and the magnetic core of the EE-type structure or the UU-type structure may be installed in the magnetic core slot of the bobbin of the transformer. Illustratively, as shown in fig. 5 and 6, the core 32 is fixed to the bobbin through a core slot 314 of the bobbin 31.

It is understood that the magnetic field strength of the leakage flux of the transformer can be calculated according to the formula H = NI/L. Wherein, N is the effective turn number of the winding, I is the value of the current of the winding of the transformer, and L is the effective magnetic path length corresponding to the test point.

As shown in fig. 14 (a), a core of a UI-type structure according to an embodiment of the present application is schematically illustrated. In the UI type structure shown in fig. 14 (a), when the effective magnetic path length corresponding to a point a is 0.5 × pi × R, the magnetic field intensity of the leakage flux of the transformer corresponding to a point a is H _A ＝NI/(0.5*π*R)。

As shown in fig. 14 (b), a magnetic core of a UU-type structure is schematically illustrated in this embodiment. In the UU type structure shown in fig. 14 (B), the effective magnetic path length corresponding to point B is pi × R, and accordingly, the magnetic field strength of the leakage flux of the transformer corresponding to point B is H _B ＝NI/(π*R)。

In the embodiment of the present application, in the case that the transformer only changes the magnetic core structure, the value of the exciting current of the transformer and the effective number of turns of the primary winding of the transformer are not changed, and only the effective magnetic path length corresponding to the test point is changed, that is, the effective magnetic path length is changed by H in (a) in fig. 14 _A Becomes H in (b) in FIG. 14 _B The magnetic field intensity of the magnetic leakage of the transformer adopting the magnetic core with the UU-shaped structure is reduced to 50 percent of the original magnetic field intensity. Consequently, the structure of magnetic core is changed into EE type structure or UU type structure by EI structure and UI structure to this application embodiment, has effectively reduced the magnetic field intensity of the magnetic leakage of transformer to multichannel output voltage's stability in the transformer working process has been improved, thereby has improved among the integrated switching power supply multiplexed outputStability of voltage.

In some embodiments, the number of air gaps of the transformer can be increased to reduce the magnetic field intensity of leakage magnetic flux of the transformer, so that the stability of the multiplexed output voltage in the working process of the transformer is improved.

In some embodiments, as shown in fig. 15 (b), the magnetic core 32 of the transformer includes a first magnetic pillar 323 and a second magnetic pillar 324 arranged in parallel, and a plurality of air gaps are disposed on the first magnetic pillar 323 and/or the second magnetic pillar 324. The transformer further includes: and a non-magnetic material filled in the plurality of air gaps. Illustratively, as shown in fig. 15 (b), the first magnetic pillar 323 is provided with two

air gaps

3231 and 3232. It should be understood that the magnetic field strength generated by the leakage flux of the transformer is calculated according to the formula H = NI/L.

As shown in FIG. 15 (a), the magnetic field strength H of the leakage flux at point B in the vicinity of the air gap on the pole 321 is based on the embodiment shown in FIG. 14 (B) _B ＝NI/(π*R)。

In fig. 15 (b), since two air gaps are provided on the first leg 323, the leakage flux of the transformer is uniformly distributed in the two air gaps, but the leakage flux of the transformer is not changed, and thus, for a single air gap of the two air gaps, the leakage flux of the transformer becomes half of the original leakage flux, i.e., NI/2, corresponding to the magnetic field strength of the leakage flux at the point C near the air gap 3231 on the first leg 323 being H _C ＝NI/(2π*R)。

It can be understood that the magnetic field intensity of the leakage flux of the point C near the air gap 3231 on the first magnetic column 323 is reduced by 50% compared with the magnetic field intensity of the leakage flux of the point B near the air gap on the magnetic column 321, which effectively reduces the magnetic field intensity of the leakage flux of the transformer.

In this way, in the embodiment of the present application, the number of the air gaps on the magnetic core of the transformer may be increased, so as to reduce the magnetic field intensity of the leakage magnetic flux of the transformer, for example, setting the number of the air gaps on the magnetic core of the transformer to 4, and reducing the magnetic field intensity of the leakage magnetic flux of the transformer to 25% of the original value. Therefore, the magnetic field intensity of magnetic leakage of the transformer can be effectively reduced by increasing the number of the air gaps on the magnetic core of the transformer, so that the stability of multi-path output voltage in the working process of the transformer is improved, and the stability of the multi-path output voltage in the integrated switching power supply is improved.

However, the number of air gaps on the magnetic core of the transformer is increased, which may cause the production process of the magnetic core of the transformer to become complicated, the assembly process of the transformer to become more complicated, and the production process complexity of the transformer is increased. Therefore, a person skilled in the art can comprehensively determine the number of the magnetic cores of the transformer on the basis of considering both the output voltage stabilization precision of the transformer and the production process complexity of the transformer.

Based on the transformer in the embodiment, the application also provides test data before and after the improvement of the transformer. Table 3 shows test data of the output voltage of the transformer multi-output power supply in the related art.

TABLE 3

When the current of the 15V main load is gradually increased from 0, the voltage of the multi-output power supply of the transformer is also gradually increased. For example, when the current of the 15V main load is 0A, the fan drive circuit 05 supply voltage UF is 23.12V. When the current of the 15V main load is 0.6A, the fan drive circuit 05 supply voltage UF is 26.11V.

When the current of the 15V main load is 0.6A, the power supply voltage of the fan drive circuit 05 is 26.11V, and compared with the rated voltage of the fan drive circuit 05 of 15V, the power supply voltage exceeds (26.11-15)/15 =74%, that is, when the current of the 15V main load is 0.6A, the power supply voltage of the fan drive circuit 05 is 1.74 times of the rated voltage, which easily causes the damage of the devices in the fan drive circuit 05.

Table 4 shows test data of the output voltage of the transformer multi-output power supply provided in the embodiment of the present application.

TABLE 4

When the current of the 15V main load is gradually increased from 0, the voltage of the multi-output power supply of the transformer is basically unchanged. For example, when the current of the 15V main load is 0A, the fan drive circuit 05 supply voltage UF is 19.01V. When the current of the 15V main load is 0.3A, the fan drive circuit 05 supply voltage UF is 19.50V. Compared with test data before the transformer is improved, the added value of the power supply voltage UF of the fan driving circuit 05 is reduced, and the stability of the multi-path output voltage of the transformer is improved.

When the current of the 15V main load is 0.3A, the power supply voltage of the fan driving circuit 05 is 19.5V, and compared with the rated voltage 15V of the fan driving circuit 05, the voltage exceeds (19.5-15)/15 =30%, that is, the power supply voltage of the fan driving circuit 05 is reduced by the improved transformer, so that the fan driving circuit 05 can normally work, and the safe operation of the switching power supply is ensured.

Optionally, an embodiment of the present application further provides a circuit substrate, where the circuit substrate includes the transformer described in the foregoing embodiment.

Optionally, an embodiment of the present application further provides a switching power supply, where the switching power supply includes the circuit substrate described in the foregoing embodiment.

The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A transformer, characterized in that the transformer comprises:

the framework is provided with a magnetic core groove; and (c) a second step of,

a plurality of windings wound on the framework in sequence from inside to outside; the plurality of windings comprises a plurality of primary windings and a plurality of secondary windings; a secondary winding is arranged between any two adjacent primary windings;

the magnetic core is arranged in the magnetic core groove and comprises a first magnetic column and a second magnetic column which are arranged in parallel; a plurality of air gaps are arranged on the first magnetic column and/or the second magnetic column, and non-magnetic-conductive materials are filled in the air gaps;

the plurality of windings includes: three primary windings, and two secondary windings disposed between any adjacent two primary windings;

the plurality of windings are wound on the framework in the sequence from inside to outside respectively as follows: the first primary winding, the first secondary winding, the second primary winding, the third secondary winding, the fourth secondary winding and the third primary winding;

the sequence of winding on the framework from inside to outside is respectively as follows: the first primary winding is tightly wound for 1 layer, the first secondary winding is wound for 1 layer in parallel, the second primary winding is wound for 2 layers in loose manner, the third secondary winding is wound for 1 layer in loose manner, the fourth secondary winding is wound for 1 layer in parallel, and the third primary winding is tightly wound for 1 layer;

and the plurality of windings are wound in the winding space between the top of the framework and the base of the framework according to the sequence.

2. The transformer of claim 1, wherein an innermost winding of the plurality of windings is a primary winding and an outermost winding is a primary winding.

3. The transformer according to claim 1 or 2, wherein the wire of the primary winding is enameled wire and the wire of the secondary winding is triple insulated wire.

4. The transformer of claim 1, wherein the core is of EE or UU configuration.

5. A circuit substrate, characterized in that it comprises a transformer according to any one of claims 1 to 4.

6. A switching power supply, characterized in that it comprises a circuit substrate according to claim 5.