JP2002299134A - Leakage transformer - Google Patents

Abstract

(57) [Abstract] [Problem] To facilitate the production and to further reduce the size. SOLUTION: In a leakage transformer in which a plurality of cores are combined and arranged so as to face each other to form a closed magnetic circuit, a rectangular vertex is formed on an inner wall surface of an upper core 20 at four corners.
Pillars 23A to 23D are provided, and the first primary winding 31a is wound so as to surround all the pillars 23A to 23D.
The second primary winding 31b is wound around the pair of column bases 23B and 23D, and the first secondary winding 41 is wound around the column base 23A.
a, and the second secondary winding 41b is wound around the column base 23C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leakage transformer suitable for use in, for example, a lighting circuit of a discharge lamp for a backlight in a display device of a notebook type personal computer, particularly, a DC / AC inverter circuit.

[0002]

2. Description of the Related Art As a conventional transformer of this type, there is a leakage transformer disclosed in Japanese Patent Application No. 2000-301188 filed by the present inventor.

The above-mentioned leakage transformer is configured by combining two cores, and the inside thereof is as shown in FIG. 10 or FIG. These FIGS. 10 and 11
, 3a and 3b are middle legs, 4a and 4b are inner grooves,
5 is an outer groove, 6 is a partition, and 7 is an outer periphery.

A first secondary winding is wound around the center leg 3a, a second secondary winding is wound around the middle leg 3b, and a primary winding is wound around the outer groove 5. With such a configuration, a small and thin one-input multi-output transformer can be obtained.

[0005]

However, in the leakage transformer described above, it is necessary to provide thin projections such as the partition 6 in addition to the middle legs 3a and 3b inside the core, making the core somewhat difficult. Since the transformer is large, there is a problem that a large occupied area is required when the transformer is mounted on an electronic device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional leakage transformer, and has as its object that the core can be easily formed and the size can be further reduced. An object of the present invention is to provide a leakage transformer capable of easily and more precisely adjusting the degree of coupling between a wire and each secondary winding.

[0007]

According to a first aspect of the present invention, there is provided a leakage transformer in which a plurality of cores are combined and opposed to each other to form a closed magnetic circuit. The first primary winding is provided at a position where four rectangular vertices are formed on the inner core wall surface on the side, and protrudes toward the inner core wall surface on the other side, and surrounds all the pedestals located at the four vertices. , And
A second primary winding is wound so as to surround a pair of column bases located at vertices opposite to the vertex, and a first secondary winding is wound around one of a pair of column bases different from the pair of column bases. The wire is wound, and the second secondary winding is wound around the other of the pair of column bases different from the pair of column bases.

The leakage transformer according to claim 2 of the present application adjusts the degree of coupling between the primary winding and each secondary winding by changing the turns ratio of the first primary winding and the second primary winding. It is characterized in that it is obtained.

In the leakage transformer according to a third aspect of the present invention, when a plurality of windings are wound around one pillar, the winding portion is wound while being divided in the length direction of the pillar. And

In the leakage transformer according to a fourth aspect of the present invention, the height of each of the column bases is formed as desired, and the gap length when a plurality of cores are combined and arranged to face each other to form a closed magnetic circuit is reduced. It is characterized by what is desired.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a leakage transformer according to the present invention will be described below with reference to the accompanying drawings. 1 to 4 show a top view, a bottom view, a side view, and a front view, respectively, of a leakage transformer according to the present invention, and FIG. 5 is a perspective explanatory view showing the inside of a leakage transformer according to the present invention as viewed from the bottom side. 6 is a cross-sectional view taken along the line AA 'in FIG. 1, FIG. 7 is a cross-sectional view taken along the line BB' in FIG. 1, and FIG.
(A) is a top view, (b) is a bottom view, and (c) is a cross-sectional view cut at the center in the longitudinal direction. 9A and 9B are explanatory views of the lower core, in which FIGS. 8A and 9A are a top view, FIG. 9B is a bottom view, and FIG. 9C is a side view as viewed from the longitudinal direction.

As shown in these figures, the upper core 20
Is a square shape with four corners chamfered. In the inner surface side of the upper core 20, a concave portion 2 having a
2 are formed, and the peripheral portions 21 and 21 form a wall.
Column bases 23A to 23D protruding toward the inner wall surface of the lower core 10 are provided upright at the four corners of the rectangle at the center of the concave portion 22.

The planar shape of the lower core 10 is 1 in a square.
It has a shape in which a substantially triangular notch is formed from two long sides. On the inner surface side of the lower core 10, an edge 11 of two short sides,
11 is slightly left, and a recess 12 is formed. Recess 1
At the center of the upper part 2, thin column bases 13A to 13D are formed at positions corresponding to the column bases 23A to 23D of the upper core 20.

The first primary winding 31a surrounds all the column bases 23A to 23D located at the four vertices of the upper core 20.
Is wound. In addition, the second pedestal 23B, 23D is positioned so as to surround
Primary winding 31b is wound.

Further, one of the pair of column bases 23A, 23C different from the pair of column bases 23B, 23D
A first secondary winding 41a is wound around 3A, and a second secondary winding 41b is wound around the other column base 23C. In the present embodiment, as shown in FIG. 6, the first primary winding 31a and the second primary winding 31b are wound without a bobbin, and are arranged at the bottom of the upper core 20. is there. In addition, the first secondary winding 41a and the second secondary winding 41b are wound around insulating bobbins, respectively, and are arranged on the opening side of the upper core 20.

On one side of the lower core 10, terminal blocks 51 and 52 are attached. The terminal block 51 is provided with terminals 511 and 512, and the terminal block 52 is provided with terminals 52 and 52.
1, 522 are provided. The terminal of the secondary winding 41a is connected to terminals 511 and 512, and the terminal of the secondary winding 41b is connected to terminals 521 and 522.

On the other side of the lower core 10, a terminal block 53 is provided.
1, 532,... Are provided. Primary winding 31
Terminals a and 31b are terminals 531 and 532, respectively.
·It is connected to the.

In the leakage transformer configured as described above, the upper core 20 and the lower core 10 are overlapped so that the concave portions 12 and 22 face each other. At this time, the column bases 13A to 13A
D and the column bases 23A to 23D are arranged to face each other, and gaps g1 to g4 are formed between the opposing surfaces of the column bases. In addition,
Since the opening surface of the upper core 20 is closed by the lower core 10 and the terminal blocks 51, 51, and 53, leakage of magnetic flux to the outside can be prevented.

The width of each of the gaps g1 to g4 can be adjusted by the height of the column bases 13A to 13D and the column bases 23A to 23D.

The magnetic flux from the first primary winding 31a is
3A to 23D, reach the lower core 10 through the gaps g1 to g4, and again through the joints between the peripheral edges 22, 22 of the upper core 20 and the edges 11, 11, of the lower core 10.
3A to 23D, the first primary winding 31a includes a first secondary winding 41a and a second secondary winding 41b wound around the column bases 23A and 23C. To join.

Most of the magnetic flux generated by the second primary winding 31b is transmitted through the gaps g1 and g4 to the column base 13 of the lower core 10.
B, 13D and the column bases 23B, 23D of the upper core 20 circulate, so that the second primary winding 31b is a combination of the secondary windings 41a and 41b wound around the column bases 23A and 23C. Hardly contributes to Therefore, the adjustment of the coupling between the primary windings 31a, 31b and the secondary windings 41a, 41b is controlled by the upper core 2
Lower core 1 arranged opposite column bases 23A to 23D
Gaps g1 formed with the column bases 13A to 13D of zero.
In addition to changing the width of g4, the primary windings 31a and 31b
Can be adjusted by changing the ratio of the number of turns of

According to the above configuration, it can be manufactured without providing a partition for isolating a plurality of secondary windings in a concave portion of a core forming a leakage transformer having multiple inputs and multiple outputs. Further, since the primary windings 31a and 31b and the secondary windings 41a and 41b are wound separately in the axial direction of the column bases 23A and 23C, the length of the core in the major axis direction can be reduced.

Further, by separately adjusting the widths of the gaps g1 to g4 and the winding ratio of the primary windings 31a and 31b, the coupling between the primary winding and the secondary winding can be adjusted more precisely. Therefore, a leakage transformer with a wide selection range of characteristics can be provided.

[0024]

As described above, the leakage transformer of the present invention protrudes toward the inner core wall surface on the other side at a position where four corners of a rectangle are formed on at least one core inner wall surface of the opposed cores. Since the column bases are provided, and a plurality of primary windings and a plurality of secondary windings are wound in the axial direction of these column bases, and the partition between the secondary windings is eliminated,
The core can be easily formed and downsized, and the coupling between the primary winding and the secondary winding can be adjusted more precisely.

[Brief description of the drawings]

FIG. 1 is a top view of a leakage transformer according to the present invention.

FIG. 2 is a bottom view of the leakage transformer according to the present invention.

FIG. 3 is a side view of the leakage transformer according to the present invention.

FIG. 4 is a front view of the leakage transformer according to the present invention.

FIG. 5 is a perspective explanatory view of the inside of the leakage transformer according to the present invention as viewed from the bottom side.

FIG. 6 is a sectional view taken along line A-A ′ in FIG. 1;

FIG. 7 is a sectional view taken along the line B-B ′ in FIG. 1;

FIGS. 8A and 8B are explanatory diagrams of an upper core used in the leakage transformer according to the present invention, wherein FIG. 8A is a top view, FIG. 8B is a bottom view, and FIG. 8C is a cross-sectional view cut at the center in the longitudinal direction.

9A and 9B are explanatory diagrams of a lower core used in the leakage transformer according to the present invention, wherein FIG. 9A is a top view, FIG. 9B is a bottom view, and FIG. 9C is a side view as viewed from a longitudinal direction.

FIG. 10 is a bottom view showing an example of an upper core used in a conventional leakage transformer.

FIG. 11 is a bottom view showing another example of the upper core used in the conventional leakage transformer.

DESCRIPTION OF SYMBOLS 10 Lower core 11 Edge 12 Depression 13A to 13D Column base 20 Upper core 21 Peripheral edge 22 Depression 23A to 23D Column base 31a First primary winding 31b Second primary winding 41a First two Secondary winding 41b Second secondary winding 51, 52, 53 Terminal block

Claims (4)

[Claims] 1. A leakage transformer in which a plurality of cores are combined and arranged so as to face each other to form a closed magnetic circuit, wherein at least one of the opposed core inner wall surfaces has four rectangular vertices. A column base protruding in the direction of the core inner wall surface on the other side is provided, and the first primary winding is wound so as to surround all the column bases located at the four vertices, and is positioned at a vertex opposed to the vertex. A second primary winding is wound so as to surround the pair of pillars, and one of the pair of pillars different from the pair of pillars,
Winding the first secondary winding, the other in a pair of column bases different from the pair of column bases,
A leakage transformer, wherein a second secondary winding is wound. 2. The coupling ratio between the primary winding and each of the secondary windings can be adjusted by changing the turn ratio of the first primary winding and the second primary winding. The leakage transformer according to claim 1. 3. The leakage according to claim 1, wherein, when a plurality of windings are wound around one pillar, the winding portion is wound separately in the length direction of the pillar. Trance. 4. The height of each of the column bases is formed as desired, and the gap length when a plurality of cores are combined and arranged to form a closed magnetic path by opposing each other is desired. Item 6. The leakage transformer according to Item 1.