CN221281883U - Transformer and voltage conversion device - Google Patents

Abstract

The embodiment of the utility model provides a transformer and voltage conversion equipment. The transformer comprises a laminated structure framework, a primary winding, a secondary winding, a feedback stage winding and a magnetic core. The primary winding is arranged in the first winding stack for inputting a first alternating voltage. The secondary winding is arranged in the second winding stack for outputting a second alternating voltage in dependence of the first alternating voltage. The feedback stage winding is arranged in the third winding stack for outputting a third alternating voltage in dependence of the second alternating voltage, the third alternating voltage being used for regulating the first alternating voltage. The magnetic core is arranged in the laminated structure framework, and the primary winding, the secondary winding and the feedback stage winding are arranged around the magnetic core. The feedback stage winding comprises a first partial winding and a second partial winding, the first partial winding and the second partial winding are alternately wound in a third winding lamination, and an insulating cladding is arranged between the first partial winding and the second partial winding.

Description

Transformer and voltage conversion device

Technical Field

Embodiments of the present utility model relate to the field of electronic circuits, and more particularly to a transformer and a voltage conversion device.

Background

The power charging device of an electronic device is generally provided with a voltage conversion device that converts an alternating voltage into a direct voltage. The power charging device may provide a direct voltage to the electronic device through, for example, a USB interface.

The voltage conversion device is mainly used for converting alternating voltage into direct voltage through a built-in transformer, and a winding arrangement mode adopted by a laminated structure of a traditional transformer can generate larger leakage inductance, so that larger electromagnetic compatibility interference (Electromagnetic Compatibility Interference, EMC) is caused.

Because the power charging device for electronic devices has a mandatory limit requirement for electromagnetic compatibility interference, the conventional technology can set an element such as a Y1 capacitor on the voltage conversion device, and the Y1 capacitor has higher withstand voltage and protection level and is used for protecting a circuit from electromagnetic interference and overvoltage. The Y1 capacitor can effectively filter common mode interference in the voltage conversion equipment, and reduce EMC interference caused by leakage inductance current of the transformer, so that normal operation of the electronic equipment is ensured. If the Y1 capacitor itself or other environmental factors cause the element to fail, the voltage on one side of the strong current can be directly connected to the USB interface end of the weak current in series, and the personal safety electric shock risk can be caused.

However, if a plurality of Y1 capacitors connected in series are used to reduce the failure probability of a single element, since the Y1 capacitor belongs to a high-voltage capacitor, the cost is high and the volume is large, which results in an increase in the product volume and the cost.

Therefore, a scheme capable of effectively reducing EMC interference is urgently required.

Disclosure of utility model

The embodiment of the utility model provides a transformer and voltage conversion equipment, which can at least partially solve the technical problems.

According to a first aspect of an embodiment of the present utility model, there is provided a transformer including a stacked structural backbone, a primary winding, a secondary winding, a feedback stage winding, and a magnetic core. The laminated structure skeleton comprises a plurality of winding laminated layers, and insulating cladding layers are arranged between adjacent winding laminated layers. The primary winding is arranged in the first winding stack for inputting a first alternating voltage. The secondary winding is arranged in the second winding stack for outputting a second alternating voltage in dependence of said first alternating voltage. The feedback stage winding is arranged in a third winding stack for outputting a third alternating voltage according to the second alternating voltage, the third alternating voltage being used for regulating the first alternating voltage. The magnetic core is arranged in the laminated structure framework, and the primary winding, the secondary winding and the feedback stage winding are arranged around the magnetic core. The feedback stage winding comprises a first partial winding and a second partial winding, wherein the first partial winding and the second partial winding are alternately wound in the third winding lamination, and an insulating cladding is arranged between the first partial winding and the second partial winding.

In the solution of this embodiment, the first partial winding and the second partial winding are disposed in the third winding stack in the stacked structure skeleton, so that the first partial winding and the second partial winding can obtain leakage inductance of each other, and an effect of parallel connection between the first partial winding and the second partial winding is formed. Especially in the case that the low-frequency leakage inductance passes through the insulating cladding more easily, the leakage inductance of the transformer is reduced by the staggered winding between the first partial winding and the second partial winding, so that EMC interference caused by the leakage inductance is reduced.

In another implementation of this embodiment, the first partial winding forms a plurality of first sections and the second partial winding forms a plurality of second sections, the plurality of first sections and the plurality of second sections being staggered along a winding direction in the third winding stack by an insulating cladding between the first partial winding and the second partial winding.

By the arrangement mode, the penetration of leakage inductance between each first section and each second section can be increased, so that the leakage inductance of the transformer is further reduced.

In another implementation of this embodiment, the number of winding turns of the first plurality of sections is gradually reduced and the number of winding turns of the second plurality of sections is gradually increased along the winding direction in the third winding stack.

By the arrangement mode, the series effect and the parallel effect between the first partial winding and the second partial winding are considered, and low-frequency leakage inductance and high-frequency leakage inductance are reduced to the greatest extent.

In another implementation of the present embodiment, the third winding stack is disposed between the first winding stack and the second winding stack among the plurality of winding stacks.

By such an arrangement, the arrangement of the individual winding stacks in a compatible winding stack structure is facilitated.

In another implementation of this embodiment, in the third winding stack, the magnetic circuit direction of the first partial winding is the same as the magnetic circuit direction of the second partial winding.

By such an arrangement, a winding manner in a compatible winding stack structure is facilitated.

In another implementation of this embodiment, the magnetic paths of the windings in adjacent winding stacks are opposite.

By this arrangement, leakage inductance between the individual winding stacks is advantageously reduced.

In another implementation of this embodiment, the windings in the plurality of first winding stacks form the primary winding by being connected in series, any two of the first winding stacks in the plurality of winding stacks being non-adjacent; or the windings in the plurality of second winding stacks are connected in series to form the secondary winding, and any two second winding stacks in the plurality of winding stacks are not adjacent.

By such an arrangement, the arrangement of the individual winding stacks in a compatible winding stack structure is facilitated.

According to a second aspect of an embodiment of the present utility model, there is provided a voltage conversion apparatus including: the transformer of the first aspect, comprising a primary winding, a secondary winding, and a feedback stage winding; an inversion control unit connected between a DC input end and the primary winding, and used for converting a DC input voltage of the DC input end into a first AC voltage according to a feedback voltage signal and outputting the first AC voltage to the primary winding; the weak current rectifying unit is connected between the secondary winding and the direct current output end and is used for rectifying the second alternating current voltage of the secondary winding into direct current output voltage; and the strong current rectifying unit is electrically connected with the feedback stage winding and is used for rectifying the third alternating voltage of the feedback stage winding to obtain the feedback voltage signal.

In the solution of this embodiment, the first partial winding and the second partial winding are disposed in the third winding stack in the stacked structure skeleton, so that the first partial winding and the second partial winding can obtain leakage inductance of each other, and an effect of parallel connection between the first partial winding and the second partial winding is formed. Especially in case that the low frequency leakage inductance passes through the insulating cladding more easily, the leakage inductance of the transformer is reduced by the staggered winding between the first partial winding and the second partial winding, thereby reducing EMC interference of the leakage inductance in the voltage converting apparatus.

In another implementation manner of this embodiment, the weak current rectifying unit includes a rectifying diode and a first voltage smoothing subunit, and the rectifying diode and the first voltage smoothing subunit are connected in parallel between the secondary winding and the dc output terminal. The first voltage smoothing subunit connected with the rectifying diode in parallel can absorb voltage spikes generated by the transmission of leakage inductance of the transformer to the secondary side, and EMC interference is further reduced.

In another implementation manner of this embodiment, the inverter control unit includes a controller, a switching tube, and a second voltage smoothing subunit, where the controller is connected to a control end of the switching tube, a first end of the switching tube is connected to a first bias low voltage, a second end of the switching tube is connected to the primary winding, and the second voltage smoothing subunit is connected in parallel between the first end and the second end of the switching tube. The second voltage smoothing subunit connected in parallel with the switching tube can absorb voltage spikes generated on the primary side by leakage inductance of the transformer, and EMC interference is further reduced.

Drawings

Some specific embodiments of the present utility model will be described in detail below by way of example and not by way of limitation with reference to the accompanying drawings. The same reference numbers will be used throughout the drawings to refer to the same or like parts or portions. It will be appreciated by those skilled in the art that the drawings are not necessarily drawn to scale.

Fig. 1A is a schematic circuit schematic diagram of a transformer according to some examples.

Fig. 1B is a schematic diagram of windings of the transformer illustrated in fig. 1A.

Fig. 2A is a circuit schematic of a transformer according to some embodiments of the utility model.

Fig. 2B is a schematic diagram of windings of the transformer of the embodiment of fig. 2A.

Fig. 3A is a winding schematic diagram of one example of a transformer of the embodiment of fig. 2B.

Fig. 3B is a winding schematic diagram of another example of the transformer of the embodiment of fig. 2B.

Fig. 3C is a winding schematic diagram of another example of the transformer of the embodiment of fig. 2B.

Fig. 4 is a schematic block diagram of a voltage conversion device according to further embodiments of the present utility model.

Fig. 5 is a circuit diagram of a voltage conversion device according to some embodiments of fig. 4.

List of reference numerals:

N1-N5: winding lamination;

110: a primary winding; 120: a secondary winding; 130: a feedback stage winding; 140: a magnetic core; 150: a laminated structure skeleton;

210: a primary winding; 220: a secondary winding; 230: a feedback stage winding; 240: a magnetic core; 250: a laminated structure skeleton;

410: a transformer; 420: an inversion control unit; 430: a weak current rectifying unit; 440: a strong current rectifying unit; 421: and a controller.

Detailed Description

In the following description, numerous specific details are set forth to describe the specific examples presented herein. It will be apparent, however, to one skilled in the art that one or more other examples and/or variations of these examples may be practiced without all of the specific details set forth below. In other instances, well-known features have not been described in detail so as not to obscure the description of the examples herein. For purposes of illustration, the same reference numbers may be used in different drawings to refer to the same elements or to additional instances of the same elements. Also, while aspects and features may be described in the various figures in some cases, it is to be understood that features from one figure or embodiment may be combined with features of another figure or embodiment, even though the combination is explicitly shown or explicitly described as a combination.

Specifically, the transformer as shown in fig. 1A includes a magnetic core 140 (provided in the bobbin 150 of fig. 1B) and a primary winding 110, a secondary winding 120, and a feedback stage winding 130 provided around the magnetic core 140. The magnetic core 140, the primary winding 110, the secondary winding 120, and the feedback stage winding 130 are disposed in a laminated structure bobbin 150 (bobbin) (refer to fig. 1B). The primary winding 110 includes winding stacks N1 and N5, the secondary winding 120 includes winding stack N3, and the feedback stage winding includes winding stacks including N2 and N4. It should be appreciated that N1-N5 may be disposed around the core 140 in the arrangement shown in FIG. 1B (e.g., in the numbered order of the winding stacks). In the winding schematic shown in fig. 1B, the stacked state of the respective winding stacks can be seen. In general, the windings of each winding stack comprise two connection terminals, one of which (as represented by the solid dots shown in fig. 1A) can be connected to the winding input or the winding output of the transformer, and the other of which can be connected to one connection terminal of the other winding stack (which can be an adjacent winding stack or a non-adjacent winding stack) of the same level winding (e.g. primary winding, secondary winding or feedback level winding), so that this winding stack is connected in series with the other winding stack, in order to increase the scalability of the winding turns of the transformer while the windings of the transformer are compactly arranged, i.e. the winding turns of each level winding can be flexibly obtained according to practical requirements. As shown in fig. 1A, winding stack N1 and winding stack N5 are connected in series through connection terminals to form a primary winding, and winding stack N2 and winding stack N4 are connected in series through connection terminals to form a feedback-stage winding. In addition, the respective winding stacks of the stacked structure bobbin may be provided with uniform connection ends, so that opposite magnetic paths may be realized in the adjacent stacked structure by employing opposite winding directions in the adjacent winding stacks, thereby reducing leakage inductance between the respective winding stacks.

In addition, each winding stack may be wrapped and wound with an insulating cladding such as an insulating tape to enhance electromagnetic isolation between each winding stack. I.e. reducing electromagnetic interference between the individual winding stacks.

In the laminated structure of a conventional transformer, the series connection between the different winding laminations still generates a certain leakage inductance, which may, for example, lead to EMC disturbances in a voltage converting device provided with the transformer.

Fig. 2A and 2B illustrate transformers according to some embodiments of the utility model. The transformer includes a primary winding 210, a secondary winding 220, a feedback stage winding 230, a magnetic core 240, and a laminated armature 250. The primary winding 210, the secondary winding 220, and the feedback stage winding 230 are disposed around a magnetic core 240. The magnetic core 240, the primary winding 210, the secondary winding 220, and the feedback stage winding 230 are disposed in a laminated structure bobbin 250 (bobbin) (refer to fig. 2B). It should be appreciated that the stacked structural backbone 250 includes a magnetic core 240 extending through each stage of windings to achieve mutual inductance between each stage of windings.

Further, a primary winding 210 is provided in the first winding stack for inputting a first alternating voltage. The secondary winding 220 is arranged in the second winding stack for outputting a second ac voltage in dependence of the first ac voltage. The feedback stage winding 230 is arranged in a third winding stack for outputting a third ac voltage in dependence of the first ac voltage. The third alternating voltage is used for adjusting the first alternating voltage.

For example, the primary winding may be wound in a close-wound manner, and the secondary winding may be wound in a loose-wound manner so that the voltage on the secondary winding side is lower than that on the primary winding side, in order to achieve a step-down function. The feedback stage windings may be wound in a sparse winding manner to enable feedback of smaller ac voltages for adjustment and handling such as an inverter control unit.

Further, the feedback stage winding 230 includes a first partial winding and a second partial winding, which are alternately wound in a third winding stack, with an insulating cladding disposed therebetween.

In the solution of this embodiment, the first partial winding and the second partial winding are disposed in the third winding stack in the stacked structure skeleton, so that the first partial winding and the second partial winding can obtain leakage inductance of each other, and an effect of parallel connection between the first partial winding and the second partial winding is formed. Especially in the case that the low-frequency leakage inductance passes through the insulating cladding more easily, the leakage inductance of the transformer is reduced by the staggered winding between the first partial winding and the second partial winding, so that EMC interference caused by the leakage inductance is reduced.

Further, as shown in fig. 2A, solid dots in each stage of windings characterize the connection ends of each winding stack in the stack structure of fig. 2B. By arranging the first partial winding N2 and the second partial winding N3 in a third winding stack in the stacked structural backbone, a parallel (sleeve) effect between the first partial winding N2 and the second partial winding N3 is created.

Without loss of generality, the winding of each winding stack of fig. 2B may include two connection terminals, one of which may be connected to a winding input terminal or a winding output terminal of the transformer, and the other of which may be connected to one connection terminal of the other winding stack (which may be an adjacent winding stack or a non-adjacent winding stack) of the same-stage winding (e.g., primary winding, secondary winding, or feedback-stage winding), such that this winding stack is connected in series with the other winding stack, in order to improve the scalability of the winding turns of the transformer while the windings of the transformer are compactly arranged, i.e., the winding turns of each stage winding may be flexibly obtained according to actual needs.

Further, the first partial winding forms a plurality of first sections along a winding direction in the third winding stack by an insulating cladding between the first partial winding and the second partial winding. For example, in fig. 3A-3C, the plurality of first sections are formed by winding (bent portions of thick solid lines) of the insulating cladding (characterized by thick solid lines) in N2. The second partial windings form a plurality of second sections. For example, in fig. 3A to 3C, the plurality of second sections are formed by winding (bent portions of thick solid lines) of the insulating cladding (characterized by thick solid lines) in N3. That is, the plurality of first sections and the plurality of second sections are staggered by a spacing. By the arrangement mode, the penetration of leakage inductance between each first section and each second section can be increased, so that the leakage inductance of the transformer is further reduced.

In some examples, as shown in fig. 3A, N2 is disposed on one side of the winding stack bobbin 250 and N3 is disposed on the other side of the winding stack bobbin 250. Compared to the situation of fig. 3B and 3C, the arrangement of fig. 3A is more advantageous in forming a series effect between the first partial winding and the second partial winding, especially in the case of high frequency leakage inductance, the series effect is advantageous in increasing the length of the magnetic circuit to reduce the high frequency leakage inductance, and the series effect is advantageous in ensuring uniformity of the induced current between the first partial winding and the second partial winding, which is also advantageous in reducing the high frequency leakage inductance.

In other examples, as shown in fig. 3C, the number of turns of the first plurality of segments is gradually reduced (illustratively, 3 turns, 2 turns, 1 turn) and the number of turns of the second plurality of segments is gradually increased (illustratively, 2 turns, 3 turns, 5 turns) along the winding direction in the third winding stack. That is, in the arrangement of fig. 3C, both the series effect and the parallel effect between the first partial winding and the second partial winding are considered, which is advantageous for maximally reducing the low-frequency leakage inductance and the high-frequency leakage inductance.

Further, among the plurality of winding stacks, a third winding stack is disposed between the first winding stack and the second winding stack. By such an arrangement, the arrangement of the individual winding stacks in a compatible winding stack structure is facilitated.

In other examples, in the third winding stack, the magnetic circuit direction of the first partial winding is the same as the magnetic circuit direction of the second partial winding. By such an arrangement, a winding manner in a compatible winding stack structure is facilitated.

In other examples, the magnetic paths of windings in adjacent winding stacks are opposite in direction. By this arrangement, leakage inductance between the individual winding stacks is advantageously reduced.

Further, the windings in the plurality of first winding stacks form a primary winding by being connected in series, any two of the plurality of first winding stacks are not adjacent, and/or the windings in the plurality of second winding stacks form a secondary winding by being connected in series, any two of the plurality of second winding stacks are not adjacent. By such an arrangement, the arrangement of the individual winding stacks in a compatible winding stack structure is facilitated.

Further, a voltage conversion apparatus including the transformer of the above-described embodiment will be described with reference to fig. 4 and 5. The voltage converting apparatus of fig. 4 includes a transformer 410, an inversion control unit 420, a weak current rectifying unit 430, and a strong current rectifying unit 440.

In particular, the transformer 410 may be the transformer shown in fig. 2A-2B and fig. 3A-3C, including a magnetic core and primary, secondary and feedback stage windings disposed around the magnetic core. The transformer 410 of the present embodiment may be the same as the above embodiments, and will not be described here again.

The inverter control unit 420 is connected between the dc input terminal and the primary winding, and converts a dc input voltage (e.g., between VCC, 220V-300V) of the dc input terminal into a first ac voltage according to the feedback voltage signal, and outputs the first ac voltage to the primary winding.

It will be appreciated that one end of the primary winding is connected to the dc input and the other end is connected to a first bias low voltage (e.g., ground).

The weak current rectifying unit 430 is connected between the secondary winding and the dc output terminal, and is configured to rectify the second ac voltage of the secondary winding into a dc output voltage (e.g., between 5V and 10V).

It will be appreciated that one end of the secondary winding is connected to the dc output and the other end is connected to a second bias low voltage (e.g., ground). It should also be appreciated that the Y1 capacitance of the conventional technique is connected between the first bias low voltage and the second bias low voltage.

The strong current rectifying unit 440 is electrically connected to the feedback stage winding, and is configured to rectify the third ac voltage of the feedback stage winding to obtain a feedback voltage signal.

It should be appreciated that one end of the feedback stage winding is connected to the controller of the inverter control unit 420 and the other end is connected to a first bias low voltage (e.g., ground).

In the solution of this embodiment, the first partial winding and the second partial winding are disposed in the third winding stack in the stacked structure skeleton, so that the first partial winding and the second partial winding can obtain leakage inductance of each other, and an effect of parallel connection between the first partial winding and the second partial winding is formed. Especially in case that the low frequency leakage inductance passes through the insulating cladding more easily, the leakage inductance of the transformer is reduced by the staggered winding between the first partial winding and the second partial winding, thereby reducing EMC interference of the leakage inductance in the voltage converting apparatus.

It is understood that the voltage converting device may further comprise another heavy current rectifying unit, different from the heavy current rectifying unit 440, for rectifying an alternating input voltage (e.g., 220V or 380V) into a direct output voltage.

The voltage conversion device may further comprise a third capacitor C3, the third capacitor C3 being connected between the dc input and the first bias low voltage. The voltage conversion device may further comprise a fourth capacitor C4, the fourth capacitor C4 being connected between the dc output and the second bias low voltage.

In other examples, the weak current rectifying unit 430 includes a rectifying diode D1, a cathode of the rectifying diode D1 is connected to the dc output terminal Vout, and an anode of the rectifying diode D1 is connected to one end of the secondary winding.

Further, the weak current rectifying unit 430 further includes a first voltage smoothing subunit, and the rectifying diode D1 and the first voltage smoothing subunit are connected in parallel between the secondary winding and the dc output terminal. The first voltage smoothing subunit connected with the rectifying diode in parallel can absorb voltage spikes generated by the transmission of leakage inductance of the transformer to the secondary side, and EMC interference is further reduced. For example, the first voltage smoothing subunit includes a first resistor R1 and a first capacitor C1, one end of the first resistor R1 is connected to one end of the first capacitor C1, the other end of the first capacitor C1 is connected to one end of the secondary winding and an anode of the rectifying diode D1, and the other end of the first resistor R1 is connected to a cathode of the rectifying diode D1 and a dc output terminal.

In other examples, as shown in fig. 5, the inverter control unit 420 may include a controller 421 and a switching tube Q1. The controller 421 is connected to the control terminal of the switching tube Q1, the first terminal of the switching tube Q1 is connected to a first bias low voltage (e.g., ground), and the second terminal of the switching tube Q1 is connected to the primary winding. Specifically, one end of the feedback stage winding may be connected to the controller 421 of the inverter control unit 420 through a rectifying diode D2 (i.e., a cathode of the rectifying diode D2 is connected to the controller, and an anode of the rectifying diode D2 is connected to one end of the feedback stage winding), so that the controller 421 adjusts the on and off frequencies of the switching tube Q1 by comparing the feedback voltage signal with a reference voltage, thereby adjusting the first ac voltage in the primary winding. Wherein the reference voltage is determined by the turns ratio between the primary winding and the feedback stage winding shown in fig. 2A, 2B and 3B.

It should be appreciated that the switching transistor Q1 may be an N-type MOS transistor. In this case, the gate of the N-type MOS transistor is a control terminal, the first terminal of the switching transistor Q1 is a source of the N-type MOS transistor, and the second terminal of the switching transistor Q1 is a drain of the N-type MOS transistor. That is, the second terminal of the switching tube Q1 is connected to the other terminal of the primary winding, which is connected to the first bias low voltage through the switching tube.

Further, the inverter control unit 420 may further include a second voltage smoothing subunit connected in parallel between the first end and the second end of the switching tube. The second voltage smoothing subunit connected in parallel with the switching tube can absorb voltage spikes generated on the primary side by leakage inductance of the transformer, and EMC interference is further reduced. For example, the second voltage smoothing subunit includes a second capacitor C2 and a second resistor R2. One end of the second capacitor C2 is connected to one end of the second resistor R2, the other end of the second capacitor C2 is connected to the drain electrode of the N-type MOS tube, and the other end of the second resistor R2 is connected to the other end of the second capacitor C2 and is connected to the source electrode of the N-type MOS tube.

Thus, particular embodiments of the present subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may be advantageous.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a article or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such article or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a commodity or device comprising such elements.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments.

The foregoing is merely exemplary of the present utility model and is not intended to limit the present utility model. Various modifications and variations of the present utility model will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the utility model are to be included in the scope of the claims of the present utility model.

Claims (10)

1. A transformer, comprising:

the laminated structure framework comprises a plurality of winding lamination layers, and insulating cladding layers are arranged between adjacent winding lamination layers;

A primary winding disposed in the first winding stack for inputting a first alternating voltage;

a secondary winding disposed in the second winding stack for outputting a second ac voltage in accordance with the first ac voltage;

A feedback stage winding arranged in a third winding stack for outputting a third ac voltage according to the second ac voltage, the third ac voltage being used to regulate the first ac voltage;

A magnetic core disposed in the laminated structure skeleton, the primary winding, the secondary winding, and the feedback secondary winding being disposed around the magnetic core;

The feedback-stage winding comprises a first partial winding and a second partial winding, wherein the first partial winding and the second partial winding are alternately wound in the third winding lamination, and an insulating cladding is arranged between the first partial winding and the second partial winding.

2. The transformer of claim 1, wherein the first partial winding forms a plurality of first sections and the second partial winding forms a plurality of second sections, the plurality of first sections and the plurality of second sections being staggered apart along a winding direction in the third winding stack by an insulating cladding between the first partial winding and the second partial winding.

3. The transformer of claim 2, wherein the number of turns of the first plurality of segments decreases and the number of turns of the second plurality of segments increases along the winding direction in the third winding stack.

4. The transformer of claim 1, wherein the third winding stack is disposed between the first winding stack and the second winding stack among the plurality of winding stacks.

5. The transformer of claim 1, wherein in the third winding stack, a magnetic path direction of the first partial winding is the same as a magnetic path direction of the second partial winding.

6. The transformer of claim 1, wherein the magnetic paths of windings in adjacent winding stacks are in opposite directions.

7. The transformer of claim 6, wherein windings in a plurality of the first winding stacks form the primary winding by being connected in series, any two of the first winding stacks in the plurality of winding stacks being non-adjacent;

Or the windings in the plurality of second winding stacks are connected in series to form the secondary winding, and any two second winding stacks in the plurality of winding stacks are not adjacent.

8. A voltage conversion device, characterized by comprising:

the transformer of any of claims 1-7, comprising a primary winding, a secondary winding, and a feedback stage winding;

An inversion control unit connected between a DC input end and the primary winding, and used for converting a DC input voltage of the DC input end into a first AC voltage according to a feedback voltage signal and outputting the first AC voltage to the primary winding;

The weak current rectifying unit is connected between the secondary winding and the direct current output end and is used for rectifying the second alternating current voltage of the secondary winding into direct current output voltage;

and the strong current rectifying unit is electrically connected with the feedback stage winding and is used for rectifying the third alternating voltage of the feedback stage winding to obtain the feedback voltage signal.

9. The voltage conversion device according to claim 8, wherein the weak current rectifying unit comprises a rectifying diode and a first voltage smoothing subunit, the rectifying diode and the first voltage smoothing subunit being connected in parallel between the secondary winding and the dc output.

10. The voltage conversion device according to claim 8, wherein the inverter control unit includes a controller, a switching tube, and a second voltage smoothing subunit, wherein the controller is connected to a control terminal of the switching tube, a first terminal of the switching tube is connected to a first bias low voltage, a second terminal of the switching tube is connected to the primary winding, and the second voltage smoothing subunit is connected in parallel between the first terminal and the second terminal of the switching tube.