EP4685826A1

EP4685826A1 - Low-profile transformer

Info

Publication number: EP4685826A1
Application number: EP24919148.7A
Authority: EP
Inventors: Chih-Ho Lai; Chun-Ching Yen; Huai-Pei Tung; Shao-dong ZHANG; Jia-Dian Lu
Original assignee: Delta Electronics Inc
Current assignee: Delta Electronics Inc
Priority date: 2024-06-07
Filing date: 2024-06-07
Publication date: 2026-01-28
Also published as: EP4685826A4; WO2025251277A1

Abstract

A thin-type transformer includes a bobbin, magnetic cores, a first winding set, and a second winding set. The bobbin includes a first plate and a hollow post. The pair of magnetic cores is disposed on two sides of the bobbin. The first winding set winds around the hollow post and disposed on the first plate. The first winding set is positioned between the pair of magnetic cores. The second winding set surrounds the first winding set and is disposed on the first plate. A spacing is defined between the second winding set and the first winding set.

Description

Technical Field

The technical field relates to a transformer, and more particularly to a thin-type transformer.

Description of Related Art

A transformer may utilize the configuration of a resonant inductor to increase the leakage inductance, thereby adjusting the electrical characteristics of the transformer, such as enhancing load adaptability and the ability to operate more effectively under varying working conditions. Additionally, the increased leakage inductance may reduce the short-circuit current of the transformer, thereby decreasing current loss in the transformer windings, improving the efficiency of the transformer, and reducing energy loss.
Moreover, in current transformer structures, a separation slot is disposed between the primary winding coil and the secondary winding coil to increase the distance therebetween, thereby serving as a substitute for the configuration of a resonant inductor. However, the disposition of such a separation slot may increase the height of the transformer, which does not meet the requirement for a lightweight and slim appearance of the thin transformer.
In view of the above drawbacks, the inventor proposes the present invention based on his expert knowledge and elaborate researches in order to solve the problems of prior art.

SUMMARY OF THE DISCLOSURE

An object of this disclosure is to provide a thin-type transformer to reduce the internal space and overall height of the transformer.
In order to achieve the object mentioned above, this disclosure provides a thin-type transformer including a bobbin, a pair of magnetic cores, a first winding set, and a second winding set. The bobbin includes a first plate and a hollow post protruding from the first plate. The pair of magnetic cores is disposed on two sides of the bobbin opposite to each other. The first winding set winds around the hollow post and disposed on the first plate. The first winding set is positioned between the pair of magnetic cores. The second winding set surrounds the first winding set and is disposed on the first plate. A spacing is defined between the second winding set and the first winding set.
In one embodiment of this disclosure, the bobbin further includes a second plate located opposite the first plate, and the hollow post is positioned between the first plate and the second plate.
In one embodiment of this disclosure, the pair of magnetic cores includes a first magnetic core and a second magnetic core. The first magnetic core includes a first base and a first core column connected with the first base, and the second magnetic core includes a second base and a second core column connected with the second base. The first base is attached to the first plate, and the second base is attached to the second plate, and the first core column and the second core column are inserted in the hollow post.
In one embodiment of this disclosure, the first winding set and the second winding set are configured to surround the hollow post on a radial direction of the hollow post.
In one embodiment of this disclosure, the spacing is equal to or greater than 0.2 mm and is equal to or less than 13.5 mm.
In one embodiment of this disclosure, the thin-type transformer further includes an insulating layer disposed in the spacing.
In one embodiment of this disclosure, a thickness of the insulating layer is equal to or greater than 0.2 mm and equal to or less than 13.5 mm.
In one embodiment of this disclosure, the first winding set and the second winding set are attached to two sides of the insulating layer, respectively.
In one embodiment of this disclosure, the thickness of the thin-type transformer is equal to or less than 20 mm.
In comparison with the related art, the bobbin of the thin-type transformer of this disclosure includes a first plate and a hollow post protruding from the first plate. A first winding set and a second winding set wind around the hollow post, and are disposed on the first board body and positioned between a pair of magnetic cores, and a spacing is defined between the first winding set and the second winding set. Furthermore, an insulating layer may be disposed in the spacing. Two sides of the insulating layer abut against the first winding set and the second winding set to maintain the spacing. Additionally, the disposition of the spacing or the insulating layer increases the leakage inductance by more than 15%, thereby allowing it to function as a substitute for the resonant inductor typically required in an LLC circuit of the related art. Therefore, the internal space and overall height of the thin-type transformer may be reduced, which facilitates automation, lowers manufacturing costs, and enhances the practical utility of this application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective exploded view of the thin-type transformer of this disclosure.
FIG. 2A is a perspective schematic view of the thin-type transformer of this disclosure.
FIG. 2B is a perspective schematic view of the bobbin of this disclosure.
FIG. 3 and FIG. 4 are sectional views of the thin-type transformer of this disclosure.
FIG. 5 and FIG. 6 are sectional views of another embodiment of the thin-type transformer of this disclosure.

REFERENCE SIGNS

1 , 1a: thin-type transformer
10 , 10a: bobbin
11: first plate
12: second plate
13 , 13a: hollow post
20 , 20a: magnetic core
21: first magnetic core
211: first base
212: first core column
22: second magnetic core
221: second base
222: second core column
30 , 30a: first winding set
40 , 40a: second winding set
50 , 50a: spacing
60a: insulating layer

DETAILED DESCRIPTION

In cooperation with attached drawings, the technical contents and detailed description of the invention are described thereinafter according to a number of embodiments, being not used to limit its executing scope.
Please refer to FIG. 1, FIG. 2A, and FIG. 2B, which are an exploded perspective view of the thin-type transformer, a perspective view of the thin-type transformer, and a perspective view of the bobbin of this disclosure. The thin-type transformer 1 of this disclosure includes a bobbin 10, a pair of magnetic cores 20, a first winding set 30, and a second winding set 40. The bobbin 10 includes a first plate 11 and a hollow post 13 protruding from the first plate 11. Specifically, the bobbin 10 includes a second plate 12 located opposite the first plate 11. The hollow post 13 is positioned between the first plate 11 and the second plate 12.
The pair of magnetic cores 20 is disposed on two sides of the bobbin 10 opposite to each other. The pair of magnetic cores 20 includes a first magnetic core 21 and a second magnetic core 22. The first magnetic core 21 includes a first base 211 and a first core column 212 connected with the first base 211. The second magnetic core 22 includes a second base 221 and a second core column 222 connected with the second base 221. Additionally, the first base 211 is attached to the first plate 11, and the second base 221 is attached to the second plate 12. The first core column 212 and the second core column 222 are inserted in the hollow post 13.
Moreover, the first winding set 30 (or primary winding) winds around the hollow post 13 and is disposed on the first plate 11, and is located between the pair of magnetic cores 20. The second winding set 40 (or secondary winding) surrounds the first winding set 30 and is also disposed on the first plate 11. A spacing 50 is defined between the second winding set 40 and the first winding set 30. In one embodiment, the spacing 50 is equal to or greater than 0.2 mm and equal to or less than 13.5 mm, but this is not limited thereto. Furthermore, the overall thickness of the thin-type transformer 1 is equal to or less than 20 mm in some embodiments.
Please also refer to FIG. 2B, FIG. 3, and FIG. 4, which are a perspective view of the bobbin and sectional views of two sides of the thin-type transformer of this disclosure. As shown in the figures, the first winding set 30 and the second winding set 40 are configured to surround the hollow post 13 on a radial direction of the hollow post 13. The first winding set 30 and the second winding set 40 are concentrically disposed on the first plate 11.
Please refer to FIG. 5 and FIG. 6, which are sectional views of another embodiment of the thin-type transformer of this disclosure. In this embodiment, the thin-type transformer 1a includes a bobbin 10a, a pair of magnetic cores 20a, a first winding set 30a, and a second winding set 40a. The bobbin 10a includes a hollow post 13a. The pair of magnetic cores 20a is disposed on two sides of the bobbin 10a opposite to each other. The first winding set 30a and the second winding set 40a are configured to surround the hollow post 13a on a radial direction of the hollow post 13a and are positioned between the pair of magnetic cores 20a. Furthermore, a spacing 50a is defined between the second winding set 40a and the first winding set 30a.
The difference in this embodiment lies in that the thin-type transformer 1a further includes an insulating layer 60a. The insulating layer 60a is made of an insulating material and is disposed in the spacing 50a. Moreover, the insulating layer 60a has a thickness of equal to or greater than 0.2 mm and equal to or less than 13.5 mm. Accordingly, the first winding set 30a and the second winding set 40a abut against two sides of the insulating layer 60a, respectively, to ensure the spacing 50a defined between the first winding set 30a and the second winding set 40a, thereby increasing the leakage inductance of the thin-type transformer 1a.
Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and improvements are intended to be embraced within the scope of the invention as defined in the appended claims.

Claims

A thin-type transformer, comprising:
a bobbin, comprising a first plate and a hollow post protruding from the first plate;

a pair of magnetic cores, disposed on two sides of the bobbin opposite to each other;

a first winding set, winding around the hollow post and disposed on the first plate, and positioned between the pair of magnetic cores; and

a second winding set, surrounding the first winding set and disposed on the first plate, wherein a spacing is defined between the second winding set and the first winding set.
The thin-type transformer according to claim 1, wherein the bobbin further comprises a second plate disposed opposite to the first plate, and the hollow post is positioned between the first plate and the second plate.
The thin-type transformer according to claim 2, wherein the pair of magnetic cores comprises a first magnetic core and a second magnetic core,
wherein the first magnetic core comprises a first base and a first core column connected with the first base,

the second magnetic core comprises a second base and a second core column connected with the second base,

the first base is attached to the first plate, the second base is attached to the second plate, and

the first core column and the second core column are inserted in the hollow post.
The thin-type transformer according to claim 1, wherein the first winding set and the second winding set are configured to surround the hollow post on a radial direction of the hollow post.
The thin-type transformer according to claim 1, wherein the spacing is equal to or greater than 0.2 mm and equal to or less than 13.5 mm.
The thin-type transformer according to claim 1, further comprising an insulating layer disposed in the spacing.
The thin-type transformer according to claim 6, wherein a thickness of the insulating layer is equal to or greater than 0.2 mm and equal to or less than 13.5 mm.
The thin-type transformer according to claim 6, wherein the first winding set and the second winding set are attached to two sides of the insulating layer, respectively.
The thin-type transformer according to claim 1, wherein a thickness of the thin-type transformer is equal to or less than 20 mm.