JPH0630303B2 - High frequency transformer - Google Patents

Description

Detailed Description of the Invention TECHNICAL FIELD OF THE INVENTION

 The present invention relates to a high frequency transformer.

[Prior art and its problems]

Generally, a high-frequency transformer has a high operating frequency, so the number of turns of the primary coil and secondary coil is small for a given voltage, and the number of magnetic flux is also small. As a result, it is compact and lightweight, and therefore can be constructed at a relatively low cost. In that case, the cross-sectional area of the winding conductor required for the high-voltage small-current side coil and the low-voltage large-current side coil, that is, if either one is the primary coil and the other becomes the secondary coil It is determined by the capacity, and the number of turns of each coil, that is, the total length of the winding conductor is determined by the applied voltage. Therefore, since the amount of the winding conductor required for the primary coil and the secondary coil increases as the capacity of the high-frequency transformer increases, the volume occupied by the coil in the transformer having a large capacity becomes large. In the coil structure in which one coil of the primary coil or the secondary coil is wound around the outer peripheral surface of the bobbin and the other coil is wound outside the bobbin as is usually done, the primary coil and the secondary coil are Between the primary coil and the secondary coil due to the fact that the magnetic coupling between them tends to become sparse and the magnetic resistance between them increases, and that when a high-frequency magnetic flux interlinks the coil, a reaction magnetic flux is generated in the winding conductor. There is a drawback that the number of effective magnetic fluxes interlinking with the next coil is reduced and conversely the number of leakage magnetic fluxes is increased, so that the electromagnetic efficiency of the transformer is reduced. Further, in the case of providing a center tap on the primary coil and the secondary coil of the high frequency coil, in the conventional coil winding method, in the coil on the high voltage small current side, which has a large number of windings, each half of the coil from the center tap to both terminals of the coil. Since it is extremely difficult to make the electrical and magnetic conditions of the coil uniform, it is inevitable that the characteristics of the high frequency transformer will be inferior.

[Object of the Invention]

In view of the above-mentioned drawbacks associated with the conventional high-frequency transformer configured so that one of the primary coil or the secondary coil is wound around the outer peripheral surface of the bobbin and the other coil is wound around the outer side of the bobbin, The invention, by a simple means, reduces the magnetic resistance between the primary coil and the secondary coil to reduce the leakage flux to increase the number of effective interlinkage magnetic fluxes, and from the center tap of each coil to both terminals thereof. It is an object of the present invention to provide a high frequency transformer having excellent transformer characteristics by winding a primary coil and a secondary coil so that the electric and magnetic conditions of a pair of half coils reaching each other are equal.

[Points of the Invention]

To achieve the above object, in the present invention, in the transformer of the present invention, the number of turns of the coil on the high-voltage, small-current side is equally divided into two, and the coil body made of a conductor having one of the turns is used as the bobbin. The coil is wound around the outer peripheral surface, the coil on the low-voltage and large-current side is wound on the outer side, and then the coil body made of the conductor of the remaining half of the coil on the high-voltage and small-current side is wound on the outer side. In addition, the conductor winding layers adjacent to each other of the two winding layers in each of the inner and outer coil bodies of the coil on the high voltage and small current side are paired to form all conductor windings of the high voltage and small current side coil. The layers are connected so as to form two series circuits to form two windings, and the two series circuits of the pair of conductor winding layers forming the two windings have equal overall lengths. As described above, the conductor winding layers of the inner and outer coil bodies are alternately connected, By providing a center tap at the turning point of the two windings, the magnetic resistance between the high-voltage small-current side coil and the low-voltage large-current side coil is reduced, and the mutual magnetic coupling is made dense. In addition, when the center tap is provided on the high-voltage small-current side coil, the electric and magnetic characteristics of the half coils from the center tap to both terminals are equalized.

Examples of the invention

Next, the details of the present invention will be described based on the embodiments shown in the drawings. The high frequency transformer according to the present invention comprises a high-voltage small-current side coil 3 and a low-voltage large-current side coil 3 in a central leg 1a of an iron core 1 made of ferrite or an amorphous magnetic material as illustrated in FIGS. 1 (A) and (B). 4 is configured so that the bobbin 2 on which the wound wire 4 is wound is inserted. In this case, if the high-voltage small-current side coil is a secondary coil, the total number of turns W of the secondary coil 3 is equally divided into two, and first, on the outer peripheral surface of the bobbin 2, as shown in FIG. A plurality of winding layers (in this case, 2 winding layers of 3C and 3D) forming W / 2 windings are wound, and both winding ends 3C ₁ and 3C _{2 of} each winding layer 3C and 3D are wound. 3D ₁ and 3D ₂ are separated so that they form independent winding layers. Next, on the outside thereof, as shown in FIG. 3, thin plate-shaped copper strips 4A, 4B, 4C.
Further, 4D is alternately stacked with an appropriate insulating sheet 6 interposed between them to form a low-voltage high-current side coil, in this case, the primary coil 4, and further, on the outside thereof, a round copper wire as illustrated in FIG. A plurality of winding layers 3A, 3B forming the remaining W / 2 turns of the secondary coil 3 are wound with a conductor consisting of, and both winding ends 3A of each winding layer 3A, 3B are wound in the same manner as described above. ₁ , 3A ₂ ; 3B ₁ and 3B ₂ are separated so that they form independent winding layers. Next, the winding end 3C ₁ of the winding layer 3C of the secondary coil 3 and the winding end 3D ₁ of the winding layer 3D are connected to each other, and the winding end 3C ₂ of the winding layer 3C is connected.
And winding end 3A ₂ of winding layer 3A, and winding end 3D ₂ of winding layer 3D.
And the winding end 3B ₂ of the winding layer 3B are connected to each other, so that the winding end 3A ₁ of the winding layer 3A and the winding end 3B ₁ of the winding layer 3B are both ends of the winding end 3C ₁ And a winding end 3D ₁ are connected to each other to form a double winding, and a center tap SP is formed at the folding point 5 as shown in FIG. 2, and the winding ends 3A ₁ and 3B are formed. _{While the} terminals SA and SB are provided on each one, as shown in FIGS. 3 and 4, the winding layer
A terminal PA is provided on one end 4A ₂ of the winding start of the lower copper strip 4A wound on the innermost side as the primary coil 4 on the outside of 3D, and the copper strip 4A
End 4B on the same side of the winding start of the upper copper strip 4B that is wound outside
₂ is provided with a center tap PP, and the copper strips 4A and 4B are wound multiple times with the insulating sheet 6 interposed therebetween.
4A ₁ is connected to the center tap PP, a terminal PB is provided at the winding end 4B ₁ of the copper strip 4B, and the secondary coil 3 and the primary coil 4 are provided with center taps PP and SP, respectively, as shown in FIG. Make instrument connections. In the high-frequency transformer according to the present invention configured as described above, it is easy to wind the primary coil 4 and the secondary coil 3 in close contact with each other, and the adjacent windings are wound. In the layers 3A and 3B and wound layers 3C and 3D, the directions of the currents flowing through the respective conductors are reversed and the inductance thereof is extremely reduced, so that the leakage flux is significantly reduced, and therefore the primary coil and the secondary coil are used as a transformer. Therefore, a high frequency transformer having a low magnetic resistance with the coil and thus a high number of effective flux linkages and a high electromagnetic efficiency can be obtained. Furthermore, among the winding layers 3A, 3B, 3C and 3D of the secondary coil 3, the winding layers 3A and 3C are connected to each other, and the winding layers 3B and 3D are connected to each other. Since the winding layer and the winding layer are sequentially connected toward the inside of the coil and the series connection circuits are evenly connected to form two windings, the conductor length from the turning point 5 to both terminals PA and PB. When the center tap SP is provided at the turning point 5, the half coils from the center tap SP to the terminals SA and SB as a transformer are electrically equalized, and the primary coil 4 and the secondary coil 3 are connected. The effect of the magnetic flux linkage is uniform because it is divided inward and outward by sandwiching it. Also, the copper strips 4A and 4B wound as the primary coil are the copper strips 4B.
The center tap PP is the start 4B ₂ of the winding and the end 4A ₁ of the copper strip 4A.
Since the lengths of PP and terminal PA are almost the same as the lengths of PP and terminal PB, the input voltage can be equally divided into two. The high voltage, small current side can also be used as the primary coil.

【The invention's effect】

According to the present invention, as described above, in the high frequency transformer, the number of turns of the coil on the high voltage and small current side is equally divided into two, and the coil body made of the conductor of one of the turns is attached to the outer peripheral surface of the bobbin, After winding the coil on the low-voltage and large-current side on the outer side of the coil, a coil body made of a conductor of the remaining half of the number of turns of the coil on the high-voltage and small-current side is wound on the outer side of the coil. A series circuit in which two conductor winding layers adjacent to each other in each of the inner and outer coil bodies of the coil on the low voltage and small current side are paired to form a pair of all conductor winding layers of the high voltage and small current side coil. To form two windings, and the inner and outer coil bodies are arranged such that the two series circuits of the pair of conductor winding layers forming the two windings have equal lengths. Alternatingly connecting the conductor winding layers of By providing a center tap at the turning point, the magnetic coupling between the high-voltage small-current side coil and the low-voltage large-current side coil is made dense to increase the number of effective interlinkage magnetic fluxes to increase the high frequency transformer. Electromagnetic efficiency as a transformer, and when equalizing the electrical and magnetic characteristics of the half coils from the center tap to both terminals when the transformer is provided with a center tap, the transformer The winding thickness of all coils can be reduced to improve the cooling effect, reduce the size and weight, and reduce the cost.The connection for two windings of each coil is made at the winding end after mounting each winding layer. Since it is obtained, it has the effect of facilitating work.

[Brief description of drawings]

FIG. 1 (A) is a perspective view illustrating a high frequency transformer according to the present invention, and FIG. 1 (B) is an AA of the transformer shown in FIG. 1 (A).
Direction schematic cross-sectional view, FIG. 2 is a schematic partial front view illustrating the arrangement and connection of the high-voltage small-current side coil of the transformer, and FIGS. 3 and 4 are low-voltage transformers, respectively. FIG. 5 shows a front view and a wiring diagram illustrating the arrangement and connection of the high-current side coil, and FIG. 5 shows a schematic wiring diagram when a center tap is provided in the transformer. 1: Iron core, 2: Bobbin, 3: High voltage, small current side coil, 3
A, 3B, 3C, 3D: Conductor winding layer of high voltage small current side coil 4:
Low voltage high current side coil, 4A: lower copper strip, 4B: upper copper strip,
5: Turn point of double winding, PP: Center tap of low voltage high current side coil.

Claims (2)

[Claims] 1. A high-frequency transformer, wherein the number of turns of the coil on the high-voltage, small-current side is evenly divided into two, and a coil body made of a conductor with one of the turns is mounted on the outer peripheral surface of the bobbin, and the coil is wound outside the bobbin. After winding the coil on the high voltage and high current side, a coil body made of a conductor of the remaining half of the number of turns of the coil on the high voltage and small current side is wound around the coil, and the coil on the high voltage and small current side is wound. So as to form a pair of all the conductor winding layers of the high voltage small current side coil by forming a pair of adjacent conductor winding layers of the two winding layers in each of the inner and outer coil bodies of the coil. The conductor windings of the inner and outer coil bodies are connected to each other to form two windings, and the two series circuits of the pair of conductor winding layers forming the two windings are equal in length to each other. Layers are alternately connected and the two turns of the winding point High frequency transformer, characterized by comprising the as providing the center tap. 2. The high-frequency transformer according to claim 1, wherein the coil on the low-voltage and high-current side is formed by winding two copper strips with insulating paper interposed therebetween. .