CN213340022U

CN213340022U - Transformer device, switching power supply and power adapter

Info

Publication number: CN213340022U
Application number: CN202022107357.3U
Authority: CN
Inventors: 曾颖宇; 万今明; 符超; 王睿欢; 孙家文; 梁思逴
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-09-23
Filing date: 2020-09-23
Publication date: 2021-06-01
Anticipated expiration: 2030-09-23

Abstract

The utility model discloses a transformer device, switching power supply and power adapter, the device includes: the primary winding module, the secondary winding and the shielding layer; the primary winding module includes: a primary winding first portion and a primary winding second portion; the primary winding first part, the secondary winding, the shielding layer and the primary winding second part are sequentially arranged in a set direction; the primary winding first part is configured to be connected with a direct current bus; the primary winding second part is configured to be connected with a main power device of a switching power supply. The utility model discloses a scheme can solve high frequency transformer and have the problem that auxiliary winding has increased circuit complexity, reaches the effect of simplifying high frequency transformer's circuit structure.

Description

Transformer device, switching power supply and power adapter

Technical Field

The utility model belongs to the technical field of the electronic circuit, concretely relates to transformer device, switching power supply and power adapter especially relate to a high frequency transformer, switching power supply circuit and use its power adapter.

Background

Some high frequency transformers for switching power supplies and power adapters have auxiliary windings, and the auxiliary windings and their loops add to the circuit complexity.

The above is only for the purpose of assisting understanding of the technical solutions of the present invention, and does not represent an admission that the above is the prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a transformer device, switching power supply and power adapter to solve high frequency transformer and have the problem that auxiliary winding has increased circuit complexity, reach the effect of simplifying high frequency transformer's circuit structure.

The utility model provides a transformer device, include: the primary winding module, the secondary winding and the shielding layer; the primary winding module includes: a primary winding first portion and a primary winding second portion; the primary winding first part, the secondary winding, the shielding layer and the primary winding second part are sequentially arranged in a set direction; the primary winding first part is configured to be connected with a direct current bus; the primary winding second part is configured to be connected with a main power device of a switching power supply.

In some embodiments, further comprising: a transformer bobbin; the primary winding first part, the secondary winding, the shielding layer and the primary winding second part are wound on the transformer framework; and adjacent parts of the primary winding first part, the secondary winding, the shielding layer and the primary winding second part are insulated by adopting an insulating tape.

In some embodiments, the first portion of the primary winding is wound around only one layer and is densely or sparsely wound over the entire layer; a first end of the primary winding first portion configured to connect to a direct current bus positive; a second end of the first portion of the primary winding configured to be connected to an intermediate node of the transformer arrangement.

In some embodiments, the secondary winding is capable of determining at least one of a number of winding strands, a wire diameter, and a number of turns based on at least one of a target number of output paths, a target output current, and a target output voltage.

In some embodiments, the shielding layer comprises a shielding winding; the shielding winding is wound by any one of metal foils, metal strips and metal wires, is fully wound by one layer and can be wound by a multi-strand parallel winding mode; the shielding winding is configured to be connected with the positive electrode of the direct current bus, and the head end and the tail end of the shielding winding are arranged in a short circuit prevention mode.

In some embodiments, the second portion of the primary winding is wound in two layers, with the same wire as the first portion of the primary winding, around the entire layer; a first end of the second portion of the primary winding configured to be connected to an intermediate node of the transformer arrangement; and the second end of the second part of the primary winding is configured to be connected with the drain electrode of a main power device of the switching power supply.

With the above device phase-match, the utility model discloses another aspect provides a switching power supply, include: the device comprises a rectification filter circuit, a high-frequency transformer, a main control unit, an alternating current low-impedance bypass circuit, a follow current and absorption circuit thereof and an output filter circuit; the main control unit comprises: a main switching device and a control system; the high-frequency transformer adopts the transformer device; the rectification filter circuit is connected to a primary winding of the transformer device and the main control unit; the secondary winding of the transformer device is connected to an output filter circuit after passing through the follow current and the absorption circuit thereof; the control system obtains electricity from the secondary side of the transformer device under a first output voltage; taking electricity from the primary side of the transformer device under a second output voltage; the output precision of the first output voltage is greater than that of the second output voltage.

In some embodiments, the rectifying and filtering circuit includes: a rectifier bridge and a filter circuit; the rectifier bridge is matched with the filter circuit; the filter circuit includes: two differential mode inductors and two capacitors; the two differential mode inductors are arranged in parallel, and the two capacitors are arranged at the end parts of the two differential mode inductors in parallel.

In some embodiments, the rectifier bridge is disposed between the two capacitors and located on either side of the two differential mode inductors, or the rectifier bridge is disposed on the same side of the two capacitors; of the two capacitors, the capacitor on the AC side is a thin film capacitor, and the capacitor on the DC side is an electrolytic capacitor.

With the switching power supply phase-match, the utility model discloses another aspect provides a power adapter, include: the switching power supply described above.

Therefore, the utility model discloses a scheme is got the electricity from direct current bus or drain electrode through the control circuit who makes the main power device, sets up the high frequency transformer that does not have auxiliary winding, solves high frequency transformer and has auxiliary winding increased the problem of circuit complexity, reaches the effect of simplifying high frequency transformer's circuit structure.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention.

The technical solution of the present invention is further described in detail by the accompanying drawings and examples.

Drawings

FIG. 1 is a schematic diagram of an embodiment of a rectifying-filtering circuit;

fig. 2 is a schematic structural diagram of an embodiment of the transformer apparatus of the present invention;

FIG. 3 is a schematic diagram of an embodiment of a switching power supply circuit;

FIG. 4 is a schematic diagram of an embodiment of a transformer winding;

FIG. 5 is a graph illustrating first test results for conducted EMI.

With reference to the accompanying drawings, the embodiments of the present invention have the following reference numerals:

1-a transformer skeleton; 2-insulating adhesive tape.

Detailed Description

To make the purpose, technical solution and advantages of the present invention clearer, the following will combine the embodiments of the present invention and the corresponding drawings to clearly and completely describe the technical solution of the present invention. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

According to the utility model discloses an embodiment provides a transformer device. Referring to fig. 1, a schematic structural diagram of an embodiment of the apparatus of the present invention is shown. The transformer device includes a primary winding module, a secondary winding (i.e., an output winding), and a shielding layer. The primary winding module includes: a primary winding first portion and a primary winding second portion.

The primary winding first portion, the secondary winding, the shielding layer, and the primary winding second portion are sequentially disposed in a predetermined direction, for example, may be sequentially disposed from the outside to the inside. The primary winding first part is configured to be connected with the positive pole of a direct current bus, namely a dead point of a circuit; the second portion of the primary winding is configured to be connected to a main power device of the switching power supply, such as to a drain of the main power device of the switching power supply.

For example: the high-frequency transformer has no auxiliary winding, only a primary winding and an output winding. The outmost layer of the transformer is the first part of the primary winding, only one layer of the outmost layer of the transformer is wound, and the outmost layer of the transformer is connected with a dead point of a direct current bus. The primary winding first part, the output winding, the shielding layer and the primary winding second part are sequentially arranged from outside to inside. The second part of the primary winding is connected with the main power device.

Therefore, the transformer structure is simplified by making the transformer structure have no auxiliary winding, the production is more convenient and the cost is lower.

In some embodiments, further comprising: transformer bobbin 1. The primary winding first part, the secondary winding, the shielding layer and the primary winding second part are wound on the transformer framework 1. And an insulating layer is arranged between the adjacent parts of the primary winding first part, the secondary winding, the shielding layer and the primary winding second part, such as an insulating tape 2.

For example: the primary winding is the primary winding, and the secondary winding is the secondary winding. In the transformer winding structure, a primary winding first part, a secondary winding, a shielding winding and a primary winding second part are sequentially arranged from outside to inside, the windings are wound on a transformer framework 1, insulating tapes 2 are adopted for insulation among the windings, and the number of turns of the tapes is usually 1-3. The primary winding is divided into two parts, and the structure can reduce the leakage inductance of the transformer to a certain extent.

In some embodiments, the first portion of the primary winding is wound around only one layer and is densely or loosely wound over the entire layer. The first end of the first part of the primary winding is configured to be connected with the positive pole of the direct current bus. A second end of the first portion of the primary winding configured to be connected to an intermediate node of the transformer arrangement.

That is to say, the first part of the primary winding is wound by only one layer and is paved on the whole layer in a close winding or sparse winding mode, one end of the first part of the primary winding is connected with the positive electrode of the direct current bus, and the other end of the first part of the primary winding is connected with the middle node of the transformer. The first part of the primary winding is arranged at the outermost layer of the transformer, the number of layers is less than that of the second part of the primary winding, and the fact that most of interference of the primary winding is shielded to a certain extent through the secondary winding in the middle is equivalent. The first part of the primary winding is connected with the circuit 'dead point' because the interference of the 'dead point' is small and does not need to be placed in the inner layer for shielding.

For example: and the secondary winding determines the number of strands, the wire diameter and the number of turns of the winding according to the number of output circuits, current and voltage. The secondary winding needs to be determined according to the actual circuit. The number of winding strands of the secondary winding, namely the number of winding strands of the secondary winding, is equal to the number of winding strands of the secondary winding.

In some embodiments, the shielding layer comprises a shielding winding. The shielding winding is wound by any one of metal foils, metal strips and metal wires, is fully wound by one layer and can be wound in a multi-strand parallel winding mode. The shielding winding is configured to be connected with the positive electrode of the direct current bus, and the head end and the tail end of the shielding winding are arranged in a short circuit prevention mode.

For example: the shielding winding is wound by metal foil, metal strip or metal wire, is fully wound by one layer, and can adopt a multi-strand parallel winding mode. The shielding winding is connected with the positive end of the direct current bus, and the head end and the tail end of the shielding winding cannot be short-circuited. The shielding winding is connected with a circuit 'dead point', coupling interference is released, and head-tail short circuit cannot form effective shielding.

In some embodiments, the second portion of the primary winding is wound in two layers and the entire layer is wound with the same wire as the first portion of the primary winding. A first end of the second portion of the primary winding configured to be connected to an intermediate node of the transformer arrangement. And the second end of the second part of the primary winding is configured to be connected with the drain electrode of a main power device of the switching power supply. Specifically, the primary winding is wound in two parts, and the inner second part is wound in two layers.

For example: the second part of the primary winding is made of the same wire as the first part and is usually wound by an integer number of layers, and the number of layers and the number of turns of the second part are not required to be close to or equal to those of the first part. One end of the second part of the primary winding is connected with the middle node of the transformer, and the other end of the second part of the primary winding is connected with the main power device. The second part of the primary winding is arranged at the innermost side of the transformer and is connected with a point with larger du/dt on a circuit, and the winding at the outer layer can effectively shield the interference.

Through a large amount of experimental verifications, adopt the technical scheme of the utility model, get the electricity from direct current bus or drain electrode through the control circuit who makes the main power device, set up the high frequency transformer that does not have auxiliary winding, can adopt differential mode inductance just can satisfy the relevant test of electromagnetic compatibility to differential mode inductance is convenient for automated production, improves production efficiency.

According to the utility model discloses an embodiment still provides a switching power supply corresponding to transformer device. The switching power supply may include: the device comprises a rectification filter circuit, a high-frequency transformer, a main control unit, an alternating current low-impedance bypass circuit, a follow current and absorption circuit thereof and an output filter circuit. The main control unit comprises: a main switching device and a control system. The high-frequency transformer adopts the transformer device.

Wherein the rectifying and filtering circuit is connected to the primary winding of the transformer device and the main control unit. And the secondary winding of the transformer device is connected to an output filter circuit after passing through the follow current and the absorption circuit thereof.

For example: the switching power supply circuit includes: the device comprises a rectification filter circuit, follow current and absorption circuits thereof, a high-frequency transformer, an alternating current low-impedance bypass circuit, a main switching device and a control circuit thereof, and an output filter circuit. The input of the alternating current power supply is connected to the rectification filter circuit, the rectification filter circuit is connected with a circuit formed by connecting a primary winding of the high-frequency transformer and the main switching device in series, a secondary winding of the high-frequency transformer is connected with follow current and an absorption circuit thereof, the follow current and the absorption circuit thereof are connected with the output filter circuit, and the output filter circuit is connected with a load. The ac low impedance bypass circuit functions to provide a bypass path for common mode interference, and is generally formed by one or more series capacitors.

And the control system obtains electricity from the secondary side of the transformer device under the first output voltage. At a second output voltage, power is taken from the primary side of the transformer device. The output precision of the first output voltage is greater than that of the second output voltage. The first output voltage is an output voltage that has a high requirement for output accuracy. The second output voltage is an output voltage with a low requirement for output accuracy.

For example: the transformer has no auxiliary winding. The control circuit may be powered by a dc bus or drain voltage. There are two types of electricity-taking methods, namely direct current bus electricity-taking and drain electrode electricity-taking. The feedback mode has two kinds, namely the requirement on the precision of the output voltage is high, secondary side feedback is adopted, and isolation is realized through a transformer or an optical coupler. If the requirement on the precision of the output voltage is not high, primary side feedback is adopted.

Therefore, the control circuit of the main power device gets power from the direct current bus or the drain electrode, the transformer has no auxiliary winding, the problems of complex circuit, multiple loop components and high cost caused by the fact that the transformer is provided with the auxiliary winding can be solved, and the circuit structure is simplified.

In some embodiments, the rectifying and filtering circuit includes: a rectifier bridge and a filter circuit; the rectifier bridge is matched with the filter circuit. The filter circuit includes: two differential mode inductances and two capacitances. The two differential mode inductors are arranged in parallel, and the two capacitors are arranged at the end parts of the two differential mode inductors in parallel.

For example: the rectification filter circuit consists of a rectification bridge and a filter circuit, the filter circuit consists of two differential mode inductors and two capacitors, the inductance values of the two differential mode inductors can be the same or different, and the capacitance values of the two capacitors can be the same or different. Adopt common mode inductance, but common mode inductance can not be inserted, the utility model discloses a scheme adopts differential mode inductance to replace common mode inductance, can realize automated production. The capacitor on the AC side is a thin film capacitor, and the capacitor on the DC side is an electrolytic capacitor. The whole structure plays a role in rectifying and filtering, and the rectifier bridge plays a role in converting alternating current into direct current. At each position, the first capacitor C1, the second capacitor C2, the first inductor L1 and the second inductor L2 can play a role in suppressing electromagnetic interference of a power grid.

In some embodiments, the rectifier bridge is disposed between the two capacitors and located on either side of the two differential-mode inductors, or the rectifier bridge is disposed on the same side of the two capacitors. Of the two capacitors, the capacitor on the AC side is a thin film capacitor, and the capacitor on the DC side is an electrolytic capacitor.

For example: the rectification filter circuit can be divided into 4 structures according to the fact that the filter component is located on the alternating current side or the direct current side, wherein a capacitor located on the alternating current side is a thin film capacitor, and a capacitor located on the direct current side is an electrolytic capacitor. The alternating current side capacitor has the function of filtering differential mode interference, and the direct current side capacitor has the function of stabilizing direct current voltage through charging and discharging. The functions are different and are selected according to the characteristics of the capacitor.

Since the processing and functions implemented by the switching power supply of this embodiment substantially correspond to the embodiments, principles, and examples of the foregoing devices, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of this embodiment.

Through a large amount of experimental verifications, adopt the technical scheme of the utility model, get the electricity through making drive and control circuit follow direct current bus or drain electrode, the transformer does not have auxiliary winding for the transformer volume is littleer, the leakage inductance is lower, circuit structure is simpler.

According to the utility model discloses an embodiment still provides a power adapter corresponding to switching power supply. The power adapter may include: the switching power supply described above.

The switching power supply and the power adapter convert the strong power of a power grid into the weak power used by electronic equipment, and are key core parts of a plurality of electronic equipment. In order to meet the requirement of electromagnetic compatibility testing, common-mode inductors are adopted as filters by most of switching power supplies and power adapters in some schemes, but the common-mode inductors cannot be inserted by machines, so that the common-mode inductors are not beneficial to automatic production, and the labor cost and the working time are increased. In some schemes, most high-frequency transformers of the switching power supply and the power adapter are provided with auxiliary windings for control of a main power device and output voltage feedback, the auxiliary windings and loops thereof increase circuit complexity, product cost is improved, the size and leakage inductance of the transformer are increased, voltage stress of the main power device is increased, and reliability of the switching power supply and the power adapter is reduced.

In some embodiments, the present invention provides a switching power supply circuit that can adopt two differential mode inductors to replace a common mode inductor and a high frequency transformer without an auxiliary winding, and can be applied to a power adapter.

In the scheme of the utility model, the main circuit adopts differential mode inductance filtering without common mode inductance;

the utility model discloses a scheme is through the special design to transformer winding for adopt the differential mode inductance to replace common mode inductance and also can satisfy the electromagnetic compatibility test, can solve common mode inductance at unable machine cartridge and be unfavorable for automated production's problem, thereby be convenient for automated production and improve production efficiency. That is to say, the utility model discloses a scheme has solved traditional filter circuit and has adopted the unable problem of inserting of machine of common mode inductance through the special design to transformer winding, adopts differential mode inductance just can satisfy the relevant test of electromagnetic compatibility to differential mode inductance is convenient for automated production, improves production efficiency.

The utility model discloses an in the scheme, make drive and control circuit get the electricity from direct current bus or drain electrode, the transformer does not have auxiliary winding. Specifically, in the scheme of the utility model, the high-frequency transformer only has a primary winding and an output winding; the outermost layer of the transformer is a first part of a primary winding, only one layer of the primary winding is wound, and the outermost layer of the transformer is connected with a dead point of a direct-current bus; the primary winding first part, the output winding, the shielding layer and the primary winding second part are sequentially arranged from outside to inside; the second part of the primary winding is connected with the main power device.

The utility model discloses a scheme makes the control circuit of main power device get the electricity from direct current bus or drain electrode, and the transformer does not have auxiliary winding, can solve the transformer and take auxiliary winding and make the circuit complicated, the return circuit components and parts are many, problem with high costs for circuit structure can simplify. That is to say, the utility model discloses an in the scheme, what the control circuit of main power device adopted is that direct current bus gets the electricity or the drain electrode gets the electricity, has solved traditional transformer and has needed auxiliary winding, the problem that circuit structure is complicated for the transformer volume is littleer, the leakage inductance is lower, circuit structure is simpler.

In some embodiments, a specific implementation process of the scheme of the present invention may be exemplarily described with reference to the examples shown in fig. 1 to 5.

Fig. 2 is a schematic structural diagram of an embodiment of a switching power supply circuit. As shown in fig. 2, the switching power supply circuit includes: the device comprises a rectification filter circuit, follow current and absorption circuits thereof, a high-frequency transformer, an alternating current low-impedance bypass circuit, a main switching device and a control circuit thereof, and an output filter circuit. The input of the alternating current power supply is connected to the rectification filter circuit, the rectification filter circuit is connected with a circuit formed by connecting a primary winding of the high-frequency transformer and the main switching device in series, a secondary winding of the high-frequency transformer is connected with follow current and an absorption circuit thereof, the follow current and the absorption circuit thereof are connected with the output filter circuit, and the output filter circuit is connected with a load.

In the example shown in fig. 2, the transformer has no auxiliary winding. There are two types of electricity-taking methods, namely direct current bus electricity-taking and drain electrode electricity-taking. Two feedback modes are provided, namely, the requirement on the precision of output voltage is high, secondary side feedback is adopted, and isolation is realized through a transformer or an optical coupler; if the requirement on the precision of the output voltage is not high, primary side feedback is adopted.

In the example of fig. 2, the ac low impedance bypass circuit functions to provide a bypass path for common mode interference, typically using one or more series capacitors. In particular, 2nF ceramic capacitors are used in series in this embodiment.

In the example shown in fig. 2, the main power device and its control circuit may be integrated in a chip, or may be discrete devices. As shown in fig. 2, the control circuit may be powered by a dc bus or drain voltage. The output voltage has two feedback modes, usually secondary side feedback, and is isolated by a transformer or an optical coupler; if the requirement on the precision of the output voltage is not high, primary side feedback can also be adopted.

Fig. 3 is a schematic structural diagram of an embodiment of a rectifying and filtering circuit. As shown in fig. 3, the rectifying and filtering circuit is composed of a rectifying bridge and a filtering circuit, the filtering circuit is composed of two differential mode inductors and two capacitors, the inductance values of the two differential mode inductors may be the same or different, and the capacitance values of the two capacitors may be the same or different.

In the example shown in fig. 3, a common mode inductor is used, but the common mode inductor cannot be inserted, and the scheme of the present invention uses a differential mode inductor instead of the common mode inductor, so that automatic production can be realized. The capacitor on the ac side is a thin film capacitor, the capacitor on the dc side is an electrolytic capacitor, and the rectifier bridge can be placed at any position as shown in fig. 3. The whole structure plays a role in rectifying and filtering, and the rectifier bridge plays a role in converting alternating current into direct current; at each position, the first capacitor C1, the second capacitor C2, the first inductor L1 and the second inductor L2 can play a role in suppressing electromagnetic interference of a power grid.

Generally, in the solution of the present invention, the rectifying and filtering circuit is located at ac or dc side according to the filtering component and can be divided into 4 structures as shown in fig. 3, wherein the capacitor located at ac side selects thin film capacitor, and the capacitor located at dc side selects electrolytic capacitor.

The structure 4 in fig. 3 is adopted, wherein 2 differential mode inductors are all h-shaped inductors of 220uH, and the first capacitor C1 and the second inductor C2 are aluminum electrolytic capacitors of 10F/400V and 33F/400V respectively.

In some embodiments, the transformer winding structure is as shown in fig. 1. The primary winding is the primary winding, and the secondary winding is the secondary winding. In the transformer winding structure, a primary winding first part, a secondary winding, a shielding winding and a primary winding second part are sequentially arranged from outside to inside, the windings are wound on a transformer framework 1, insulating tapes 2 are adopted for insulation among the windings, and the number of turns of the tapes is usually 1-3.

The first part of the primary winding is only wound on one layer, the whole layer is paved in a close winding or sparse winding mode, one end of the first part of the primary winding is connected with the positive electrode of the direct-current bus, and the other end of the first part of the primary winding is connected with the middle node of the transformer.

And the secondary winding determines the number of strands, the wire diameter and the number of turns of the winding according to the number of output circuits, current and voltage.

The shielding winding is wound by adopting metal foil, metal strip or metal wire, is fully wound by one layer and can adopt a multi-strand parallel winding mode; the shielding winding is connected with the positive end of the direct current bus, and the head end and the tail end of the shielding winding cannot be short-circuited.

The second part of the primary winding is made of the same wire as the first part and is usually wound by an integer number of layers, and the number of layers and the number of turns of the second part are not required to be close to or equal to those of the first part; one end of the second part of the primary winding is connected with the middle node of the transformer, and the other end of the second part of the primary winding is connected with the main power device.

In particular, in one embodiment, the number of output paths is 1, the wire diameter of the secondary winding is 0.4mm, and 2 strands are wound in parallel and fully wound by 2 layers; the wire diameter of the first part of the primary winding is 0.3mm, and the single strand is wound all over one layer; the diameter of the second part of the primary winding is 0.3mm, and the single strand is wound fully in 2 layers; the diameter of the shielding winding wire is 0.18mm, and 4 strands are wound in parallel and are fully wound.

The utility model discloses an in the scheme, whole circuit is comparatively succinct, the later stage PCB overall arrangement of being convenient for, and the device lectotype is favorable to automatic assembly, can guarantee comparatively excellent EMC performance in control circuit low-cost. Fig. 4 shows the actual measurement result of conducted EMI of the switching power supply circuit according to the embodiment, where the margin is higher than 7.54dB in the frequency band of 150 kHz to 30MHz, which completely meets the national standard requirements.

Fig. 4 and 5 are diagrams showing the technical effects and advantages of the present invention when applied to a typical circuit, i.e. having good EMI-conducting performance; the transformer structure has no auxiliary winding, the transformer structure is simplified, the production is more convenient, and the cost is lower.

Since the processing and functions implemented by the method of this embodiment substantially correspond to the embodiments, principles, and examples of the switching power supply, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of this embodiment.

Through a large number of tests, the technical scheme of the embodiment is adopted, and the two differential mode inductors are adopted to replace a common mode inductor and a switching power supply circuit without an auxiliary winding of a high-frequency transformer, so that the switching power supply circuit is applied to a power adapter, the circuit structure can be simplified, and the production efficiency can be improved.

In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.

The above description is only an example of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A transformer apparatus, comprising: the primary winding module, the secondary winding and the shielding layer; the primary winding module includes: a primary winding first portion and a primary winding second portion; wherein,

the primary winding first part, the secondary winding, the shielding layer and the primary winding second part are sequentially arranged according to a set direction;

the primary winding first part is configured to be connected with a direct current bus; the primary winding second part is configured to be connected with a main power device of a switching power supply.

2. The transformer apparatus of claim 1, further comprising: a transformer bobbin (1);

the primary winding first part, the secondary winding, the shielding layer and the primary winding second part are wound on the transformer framework (1); and an insulating layer is arranged between adjacent parts of the primary winding first part, the secondary winding, the shielding layer and the primary winding second part.

3. The transformer arrangement according to claim 1 or 2, wherein the first part of the primary winding is wound only one layer and is laid over the entire layer in a close-wound or open-wound manner; a first end of the primary winding first portion configured to connect to a direct current bus positive; a second end of the first portion of the primary winding configured to be connected to an intermediate node of the transformer arrangement.

4. The transformer arrangement according to claim 1 or 2, wherein the secondary winding is capable of determining at least one of a number of winding strands, a wire diameter and a number of turns based on at least one of a target output number, a target output current and a target output voltage.

5. The transformer arrangement according to claim 1 or 2, characterized in that the shielding layer comprises a shielding winding; the shielding winding is wound by any one of metal foils, metal strips and metal wires, is fully wound by one layer and can be wound by a multi-strand parallel winding mode; the shielding winding is configured to be connected with the positive electrode of the direct current bus, and the head end and the tail end of the shielding winding are arranged in a short circuit prevention mode.

6. The transformer arrangement according to claim 1 or 2, wherein the second part of the primary winding is wound in two layers and in the entire layer using the same wire as the first part of the primary winding; a first end of the second portion of the primary winding configured to be connected to an intermediate node of the transformer arrangement; and the second end of the second part of the primary winding is configured to be connected with the drain electrode of a main power device of the switching power supply.

7. A switching power supply, comprising: the device comprises a rectification filter circuit, a high-frequency transformer, a main control unit, an alternating current low-impedance bypass circuit, a follow current and absorption circuit thereof and an output filter circuit; the main control unit comprises: a main switching device and a control system; the high-frequency transformer, which adopts the transformer device of any one of claims 1 to 6; wherein,

the rectification filter circuit is connected to the primary winding of the transformer device and the main control unit; the secondary winding of the transformer device is connected to the output filter circuit after passing through the follow current and the absorption circuit thereof;

the control system obtains electricity from the secondary side of the transformer device under a first output voltage; taking electricity from the primary side of the transformer device under a second output voltage; the output precision of the first output voltage is greater than that of the second output voltage.

8. The switching power supply according to claim 7, wherein the rectifying-filtering circuit comprises: a rectifier bridge and a filter circuit; the rectifier bridge is matched with the filter circuit; the filter circuit includes: two differential mode inductors and two capacitors; the two differential mode inductors are arranged in parallel, and the two capacitors are arranged at the end parts of the two differential mode inductors in parallel.

9. The switching power supply according to claim 8, wherein the rectifier bridge is disposed between the two capacitors and on either side of the two differential mode inductors, or the rectifier bridge is disposed on the same side of the two capacitors; of the two capacitors, the capacitor on the AC side is a thin film capacitor, and the capacitor on the DC side is an electrolytic capacitor.

10. A power adapter, comprising: the switching power supply according to any one of claims 7 to 9.