JP3130200B2 - Trance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer used as a switching power supply for various electronic devices.

[0002]

2. Description of the Related Art A transformer for a switching power supply comprises an input-side primary winding, an output-side secondary winding, and an auxiliary primary winding for stabilizing oscillation and output voltage. The auxiliary primary winding is on the input side, and it is necessary to provide electrical and structural insulation required for operation and safety standards between the primary and secondary windings and the auxiliary primary and secondary windings. There is. In order to achieve ideal operation, the degree of coupling between the primary winding and the secondary winding and between the secondary winding and the auxiliary primary winding is improved, the leakage inductance is reduced, and the capacitance between the windings is reduced. It is necessary to reduce the stray capacitance of each winding. This is because the transient vibration during the switching operation is reduced, the generation and transmission of unnecessary noise components are prevented, and the power supply efficiency is not deteriorated.

A conventional transformer is configured as shown in FIGS. That is, in FIG. 5, one of the two primary windings 2a, which is divided into two winding frames 1 having a brim at both ends, is wound, and the secondary winding 3 is wound on the primary winding 2a. The remaining primary winding 2b is wound on the wire 3, the auxiliary primary winding 4 is wound on the primary winding 2b, and the magnetic core 5 is incorporated in the winding frame 1. The windings are insulated by an adhesive tape 6 and the winding width is regulated by an insulating spacer 7. Since the facing area between the windings is large and the thickness of the adhesive tape 6 is kept to a necessary minimum, the degree of coupling is high and the capacitance is large.

In FIG. 6, a winding frame 10 having five divided winding grooves 9 divided by four dividing collars 8 is provided with
A primary winding 11 divided into three is wound around the uppermost divided winding groove 9, and a secondary winding 12 divided into two is wound around the second divided winding groove 9 from the bottom and the second divided winding groove 9 from the top, The auxiliary primary winding 13 divided into two parts is wound on the primary winding 11 wound around the lowermost and middle divided winding grooves 9, and the magnetic core 14 is incorporated in the winding frame 10. The primary winding 11 divided into three parts, the secondary winding 12 divided into two parts, and the auxiliary primary winding 13 divided into two parts have a split collar 8.
The coupling degree is small and the capacitance is small because of its thickness.

[0005]

In recent years, various types of electronic equipment have been reduced in size, weight, efficiency, and cost. One of the key technologies is the reduction of noise in switching power supplies. In video-related equipment, generation and transmission of unnecessary noise components from low to high frequencies must be prevented. For this reason, by placing importance on the degree of coupling between the primary winding and the secondary winding, it is necessary to place importance on the reduction of the capacitance between the windings and the stray capacitance of each winding. However, in operation, it is necessary to maintain electrical and structural insulation necessary for safety standards and to improve the degree of coupling between the secondary winding and the auxiliary primary winding.

In the configuration of FIG. 5 of the related art, the capacitance is large, and in the configuration of FIG. 6, the degree of coupling between the secondary winding and the auxiliary primary winding is small. This problem prevents the switching power supply from reducing noise.

In order to solve the problems in the above-described conventional configuration, the present invention improves the degree of coupling between the secondary winding and the auxiliary primary winding, although the degree of coupling between the primary winding and the secondary winding is slightly smaller. It is an object of the present invention to provide a low-noise transformer having low capacitance and maintaining electrical and structural insulation.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a winding frame having a plurality of divided winding grooves formed by a plurality of divided collars, comprising a primary winding, a secondary winding, and an auxiliary primary winding. All or a part of each is divided in parallel or in series, and the divided part of the primary winding and the divided part of the secondary winding are alternately wound for each divided winding groove, and the whole or divided part of the auxiliary primary winding is two
The winding is wound above or below the next winding , and the magnetic core is incorporated therein.

[0009]

With the above construction, the primary winding and the secondary winding are divided by the split collar, and the thickness of the primary winding reduces the degree of coupling and the capacitance. The secondary winding and the auxiliary primary winding are in direct contact and the degree of coupling is large and the capacitance is also large,
The auxiliary primary winding is typically a few turns and the capacitance is negligible compared to the capacitance of the primary and secondary windings.

Therefore, although the degree of coupling between the primary winding and the secondary winding is sacrificed, the capacitance between each winding and the stray capacitance of each winding are reduced, and electrical and structural insulation is maintained. ,
The degree of coupling between the secondary winding and the auxiliary primary winding can be improved.

It is to be noted that the degree of coupling between the primary winding and the secondary winding is improved,
Further reduction in capacitance can be achieved by increasing the split collar and increasing the split bobbin. In operation, electrical and structural insulation required by safety standards can be maintained by the collar, and safety standards can be met by using a conductor having three layers of insulating coating on the auxiliary primary winding.

[0012]

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a transformer according to a first embodiment of the present invention, and FIG. 2 is a connection diagram of the transformer. As shown in FIG. 1, a primary winding 34 divided into three and connected in series to a winding frame 31 having five divided winding grooves 33 divided by four divided And the secondary winding 3 divided into two and connected in parallel to the uppermost divided winding groove 33.
5 is wound around the divided winding grooves 33 of the second stage from the bottom and the second stage from the top, and the auxiliary primary winding 37 divided into two and connected in parallel using a conductor wire coated with three layers of insulation is described above. Secondary winding 35
And a transformer is constructed by incorporating the magnetic core 38 into the winding frame 31.

Here, a conductive wire having three layers of insulating coating and
Forms the first insulating coating layer on the outer periphery of the metal conductor wire,
A second insulating coating layer is formed on the outer periphery, and 3
It is formed by forming a second insulating coating layer.

With this configuration, the primary winding 34 and the secondary winding 35 are divided by the dividing collar 32, and the thickness of the primary winding 34 and the secondary winding 35 reduce the degree of coupling and the capacitance. However, in the present embodiment, the number of split collars is set to four and the number of split winding grooves is set to five, so that the degree of coupling is slightly reduced as compared with the conventional transformer shown in FIG. Although the secondary winding 35 and the auxiliary primary winding 37 are in direct contact with each other, the coupling degree is large and the capacitance is large, the auxiliary primary winding 37 is generally several turns, and the capacitance is the primary winding 34. And the capacitance of the secondary winding 35 is so small that it can be ignored. Operationally, the electrical and structural insulation required by safety standards can be maintained by the split primary 32 and the auxiliary primary winding 37 using three layers of insulated conductors. In the present embodiment, the secondary windings 35 are divided in parallel. However, it is also easy to divide the windings through which a large current flows in each winding in parallel so that each winding has one type of wire diameter.

Accordingly, although the degree of coupling between the primary winding 34 and the secondary winding 35 is slightly sacrificed, the degree of coupling between the secondary winding 35 and the auxiliary primary winding 37 is improved, the capacitance between the windings, and The stray capacitance of the wire can be reduced and the electrical and structural insulation can be maintained. Furthermore, unification of conductor types,
By using a configuration that does not require an insulating tape, the number of parts and the number of manufacturing steps can be reduced.

Embodiment 2 Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a sectional view of a transformer according to a second embodiment of the present invention, and FIG. 4 is a connection diagram of the transformer. As shown in FIG. 3, one secondary winding 36 is wound around a winding frame 31 having six divided winding grooves 33 divided by five dividing collars 32 around the lowermost divided winding groove 33, A primary winding 34 divided into three and connected in series is wound around the second-stage, fourth-stage, and uppermost-stage divided winding grooves 33 from the bottom, and an auxiliary primary winding using a conductor wire coated with three layers of insulation. 37 is wound around the third divided winding groove 33 from the bottom, and the other secondary winding 35 divided into two and connected in parallel is connected to the auxiliary primary winding 37 of the third divided winding groove 33 from the bottom.
The winding is wound around the second divided winding groove 33 from the top and bottom, and the magnetic core 38 is incorporated into the winding frame 31 to form a transformer.

In this embodiment, one secondary winding 3 has a two-output specification.
5 and the other secondary winding 36 are required, and the output of the secondary winding 35 is an example where high stability is required. With this configuration, the degree of coupling between the secondary winding 35 and the auxiliary primary winding 37 is slightly smaller than in the first embodiment, but the primary winding 34
And the degree of coupling between the auxiliary primary winding 37 and the
The influence of the change applied to the primary winding 34 such as the input voltage change is hardly given to the auxiliary primary winding 37, and the oscillation and the output voltage can be stabilized. Although the secondary winding 36 is added as an output that does not require stability, a high stability output can be obtained by winding the secondary winding 36 under the secondary winding 35.

Therefore, in addition to the effects shown in the first embodiment, fine adjustment of the degree of coupling can be easily achieved, and it is possible to cope with a multi-output specification.

In addition, in addition to the above embodiment, all or a part of each of the windings is divided in parallel or in series so that the primary winding, the secondary winding, and the auxiliary primary winding have one kind of wire diameter. Cost reduction can be achieved. Auxiliary primary winding divisions are wound below some or all secondary winding divisions,
Fine adjustment of the degree of coupling between the auxiliary primary winding and the secondary winding is possible. If multiple secondary windings are required in the multi-output specification, all or part of each of the multiple secondary windings is divided or arranged in parallel or in series to achieve the required stability of the output voltage. Accordingly, the degree of coupling with the primary winding or another secondary winding can be finely adjusted.

[0022]

As described above, the present invention is a transformer for a switching power supply which has advantages such as low noise, flexible adaptation to various power supply specifications, reduction in the number of parts and reduction in the number of manufacturing steps. That is, it is possible to provide a transformer for a switching power supply, which is optimal for electronic devices that are becoming smaller, lighter, more efficient, and lower in cost, thereby increasing their industrial value.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a transformer showing a first embodiment of the present invention.

FIG. 2 is a connection diagram of a transformer showing the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of a transformer showing a second embodiment of the present invention.

FIG. 4 is a connection diagram of a transformer showing a second embodiment of the present invention.

FIG. 5 is a sectional view of a conventional transformer.

FIG. 6 is a sectional view of a conventional transformer.

[Explanation of symbols]

 31 winding frame 32 split brim 33 split winding groove 34 primary winding 35 secondary winding 36 another secondary winding 37 auxiliary primary winding 38 core

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masayuki Mizushima 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-58-30111 (JP, A) 47571 (JP, A) Japanese Utility Model 3-110720 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01F 27/00-27/42

Claims (4)

(57) [Claims] 1. A winding frame having a plurality of divided winding grooves by a plurality of dividing collars, wherein all or a part of each of a primary winding, a secondary winding, and an auxiliary primary winding is divided in parallel or in series and divided. The windings of the primary winding and the windings of the secondary winding are alternately wound for each winding groove ,
A transformer that is wound above or below a secondary winding and incorporates a magnetic core. 2. The transformer according to claim 1, wherein the auxiliary primary winding is a conductor having three layers of insulation coating. 3. The transformer according to claim 1, wherein the primary winding, the secondary winding, and the auxiliary primary winding have one type of conductor diameter. 4. The transformer according to claim 1, wherein all or a part of each of the plurality of secondary windings is divided in parallel or in series.