JP3792526B2 - Leakage transformer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a leakage transformer suitable for use in, for example, a lighting circuit for a discharge lamp for a backlight in a display device of a notebook personal computer, particularly a DC / AC inverter circuit.
[0002]
[Prior art]
As this type of conventional transformer, there is a leakage transformer disclosed in Japanese Patent Application No. 2000-301188 filed by the present inventor.
[0003]
The above leakage transformer is configured by combining two cores, and the inside is as shown in FIG. 10 or FIG. 10 and 11, 3a and 3b are middle legs, 4a and 4b are inner groove portions, 5 is an outer groove portion, 6 is a partition wall portion, and 7 is an outer peripheral portion.
[0004]
Then, the first secondary winding is wound around the middle leg 3a, the second secondary winding is wound around the middle leg 3b, and the primary winding is wound around the outer groove portion 5. With such a configuration, a small and thin single-input multiple-output transformer can be obtained.
[0005]
[Problems to be solved by the invention]
However, in the above-described leakage transformer, it is necessary to provide a thin protrusion such as the partition wall portion 6 in addition to the middle legs 3a and 3b on the inner side of the core, and it is somewhat difficult to create the core. There is a problem that a large occupied area is required when mounting the device.
[0006]
The present invention has been made as a solution to the problems of the conventional leakage transformer described above, and its purpose is to facilitate the creation of the core and to further reduce the size of the primary winding and each of the primary windings. It is an object of the present invention to provide a leakage transformer in which the degree of coupling with a secondary winding can be adjusted easily and more precisely.
[0007]
[Means for Solving the Problems]
The leakage transformer according to claim 1 of the present application is a leakage transformer in which a plurality of cores are combined and arranged opposite to form a closed magnetic circuit. The leakage transformer has a quadrilateral shape on at least one of the opposed inner core walls . A column base protruding in the direction of the inner wall surface of the core on the other side is provided at a position to be the four apexes, and the first primary winding is wound so as to surround all the column bases positioned at the four apexes. The second primary winding is wound so as to surround the pair of column bases located at the opposite vertices of the two, and the first secondary winding is provided on one of the pair of column bases different from the pair of column bases. The second secondary winding is wound around the other of the pair of column bases different from the pair of column bases.
[0008]
In the leakage transformer according to claim 2 of the present application, the degree of coupling between the primary winding and each secondary winding can be adjusted by changing the turns ratio of the first primary winding and the second primary winding. It is characterized by that.
[0009]
The leakage transformer according to claim 3 of the present application is characterized in that when a plurality of windings are wound around one column base, the winding portion is wound separately in the length direction of the column base.
[0010]
In the leakage transformer according to claim 4 of the present application, the height of each of the column bases is formed as desired, and a gap length is desired when a plurality of cores are combined and arranged to face each other to form a closed magnetic circuit. It is characterized by that.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a leakage transformer according to the present invention will be described below with reference to the accompanying drawings. 1 to 4 are a top view, a bottom view, a side view, and a front view, respectively, of the leakage transformer according to the present invention, and FIG. 5 is a perspective explanatory view of the inside as viewed from the bottom side of the leakage transformer according to the present invention. 6 is a cross-sectional view taken along the line AA ′ of FIG. 1, FIG. 7 is a cross-sectional view taken along the line BB ′, and FIG. 8 is an explanatory view of the upper core used in the leakage transformer according to the present invention. (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. FIGS. 9A and 9B are explanatory views of the lower core. FIGS. 8 and 9 are respectively a top view, a bottom view, and a side view seen from the longitudinal direction.
[0012]
As shown in these drawings, the planar shape of the upper core 20 is a square shape with four corners chamfered. On the inner surface side of the upper core 20, a concave portion 22 with a corner cut out in a circular shape is formed, and the peripheral portions 21 and 21 form a wall. At the center of the recess 22, column bases 23 </ b> A to 23 </ b> D projecting in the direction of the inner wall surface of the lower core 10 are erected at positions corresponding to the four vertices of the rectangle.
[0013]
The planar shape of the lower core 10 is a shape in which a substantially triangular notch is formed from one long side of a quadrangle. On the inner surface side of the lower core 10, a recess 12 is formed, leaving a few short edges 11, 11. Thin column bases 13 </ b> A to 13 </ b> D are formed at positions corresponding to the column bases 23 </ b> A to 23 </ b> D of the upper core 20 at the center of the recess 12.
[0014]
A first primary winding 31a is wound so as to surround all the column bases 23A to 23D located at the four vertices of the upper core 20. A second primary winding 31b is wound so as to surround the pair of column bases 23B and 23D located at the vertices opposite to the vertices.
[0015]
Further, the first secondary winding 41a is wound around one column base 23A of a pair of column bases 23A and 23C different from the pair of column bases 23B and 23D, and the second column base 23C is connected to a second column base 23C. Secondary winding 41b is wound. In the present embodiment, as shown in FIG. 6, the first primary winding 31 a and the second primary winding 31 b are wound in a bobbinless manner and are arranged at the bottom of the upper core 20. is there. Further, the first secondary winding 41 a and the second secondary winding 41 b are respectively wound around an insulating bobbin and arranged on the opening side of the upper core 20.
[0016]
Terminal blocks 51 and 52 are attached to one side of the lower core 10, terminals 511 and 512 are provided on the terminal block 51, and terminals 521 and 522 are provided on the terminal block 52. ing. Terminals of the secondary winding 41 a are connected to terminals 511 and 512, and terminals of the secondary winding 41 b are connected to terminals 521 and 522.
[0017]
Moreover, the terminal block 53 is attached to the other side part of the lower core 10, and the terminal block 53 is provided with terminals 531, 532,. The terminals of the primary windings 31a and 31b are connected to terminals 531, 532,.
[0018]
In the leakage transformer configured as described above, the upper core 20 and the lower core 10 are stacked so that the recesses 12 and 22 face each other. At this time, the column bases 13A to 13D 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 obstruct | occluded by the lower core 10 and the terminal blocks 51, 51, and 53, it can prevent that a magnetic flux leaks outside.
[0019]
The widths of the gaps g1 to g4 can be adjusted by the heights of the column bases 13A to 13D and the column bases 23A to 23D.
[0020]
The magnetic flux generated by the first primary winding 31a exits from the column bases 23A to 23D, reaches the lower core 10 through the gaps g1 to g4, and the peripheral edges 22 and 22 of the upper core 20 and the edge 11 of the lower core 10; 11 is circulated through the closed magnetic path that returns to the column bases 23A to 23D again through the joint with the first base winding 31a. Therefore, the first primary winding 31a is a first secondary winding wound around the column base 23A and the column base 23C. Coupled to line 41a and second secondary winding 41b.
[0021]
Most of the magnetic flux generated by the second primary winding 31b circulates between the column bases 13B and 13D of the lower core 10 and the column bases 23B and 23D of the upper core 20 via the gaps g1 and g4. The winding 31b hardly contributes to the coupling between the secondary windings 41a and 41b wound around the column base 23A and the column base 23C. Therefore, the adjustment of the coupling between the primary windings 31a and 31b and the secondary windings 41a and 41b is performed by adjusting the column bases 13A to 13D of the lower core 10 facing the column bases 23A to 23D of the upper core 20. This means that it can be adjusted not only by changing the widths of the gaps g1 to g4 formed in (5) but also by changing the ratio of the number of windings of the primary windings 31a and 31b.
[0022]
With the configuration described above, the multi-input and multi-output leakage transformer can be formed without providing a partition wall for isolating a plurality of secondary windings in the concave portion of the core. 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 shortened.
[0023]
Furthermore, the coupling between the primary winding side and the secondary winding side can be adjusted more precisely by separately adjusting the widths of the gaps g1 to g4 and the winding ratios of the primary windings 31a and 31b. Therefore, a leakage transformer having a wide selection range of characteristics can be provided.
[0024]
【The invention's effect】
As described above, the leakage transformer of the present invention is provided with the column base protruding in the direction of the inner wall surface on the other side at the position where the four inner corners of the quadrilateral are formed on the core inner wall surface on at least one side of the opposed cores. In addition, it is configured by winding a plurality of primary windings and a plurality of secondary windings in the axial direction of these column bases, and since the partition between the secondary windings is eliminated, it is easy to create a core, In addition, the size can be reduced, and the coupling between the primary winding side and the secondary winding side 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 a leakage transformer according to the present invention.
FIG. 3 is a side view of a leakage transformer according to the present invention.
FIG. 4 is a front view of a 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 seen from the bottom surface 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. FIG.
8A and 8B are explanatory views of an upper core used in the leakage transformer according to the present invention, where FIG. 8A is a top view, FIG. 8B is a bottom view, and FIG. 8C is a cross-sectional view taken at the center in the longitudinal direction.
9A and 9B are explanatory views of a lower core used in the leakage transformer according to the present invention, in which FIG. 9A is a top view, FIG. 9B is a bottom view, and FIG. 9C is a side view as viewed from the 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 an upper core used in a conventional leakage transformer.
[Explanation of symbols]
10 Lower core 11 Edge portion 12 Recesses 13A to 13D Column base 20 Upper core 21 Peripheral portion 22 Recesses 23A to 23D Column base 31a First primary winding 31b Second primary winding 41a First secondary winding 41b First 2 secondary windings 51, 52, 53 Terminal block

Claims (4)

In a leakage transformer in which a plurality of cores are combined and opposed to form a closed magnetic circuit,
A column base that protrudes toward the core inner wall surface on the other side is provided at a position that becomes the four vertices of the quadrilateral on the core inner wall surface on at least one side that is arranged oppositely,
The first primary winding is wound so as to surround all the column bases positioned at the four vertices, and the second primary winding is configured so as to surround a pair of column bases positioned at the opposite vertices of the tops. Winding
The first secondary winding is wound around one of the pair of column bases different from the pair of column bases,
A leakage transformer, wherein a second secondary winding is wound around the other of a pair of column bases different from the pair of column bases.   2. The coupling degree between the primary winding and each secondary winding can be adjusted by changing the turns ratio of the first primary winding and the second primary winding. Leakage transformer.   The leakage transformer according to claim 1, wherein when a plurality of windings are wound on one column base, the winding portion is wound separately in the length direction of the column base.   The height of each column base is formed as desired, and a gap length when a plurality of cores are combined and arranged to face each other to form a closed magnetic circuit is desired. Leakage transformer.

Images