JPH07201586A - Pulse transformer for isdn - Google Patents

Abstract

PURPOSE:To provide a pulse transformer which can be manufactured thin while satisfying the requested characteristics of a pulse transformer for ISDN. CONSTITUTION:This pulse transformer for ISDN is constituted of a plurality of pipe-like magnetic cores 1 which are made by winding a Co-base amorphous ribbon in the maximum thickness of 15mum or below, a storing space in which two or more pipe-like magnetic cores can be adjacently installed, a case having a terminal for wiring, and a winding 2 which passes through through holes of the pipe-like magnetic cores 1 which are adjacently installed in the storing space. A lead wire of the winding 2 is connected to the terminal for wiring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ISDN pulse transformer.

[0002]

2. Description of the Related Art A pulse transformer for ISDN is 20 kHz.
It is necessary to guarantee a high inductance of 20 mH or more in z, and to realize a low capacitance and a low leakage inductance. Conventionally, a bobbin with a winding is combined with a pot type, EI type, EE type, or the like ferrite core. Alternatively, the ring-shaped ferrite magnetic core is provided with windings. Alternatively, the winding core is formed by attaching an insulating case or epoxy coating to a winding magnetic core formed by winding a Co-based amorphous material.

[0003]

Since the recent ISDN pulse transformer is housed in an IC card, the minimum height is 5 mm or less, and in reality, the height is 3.6 mm or 2.8 mm.
The following ultra-thin dimensions are required. Also, the card size is limited to 54 × 85.6 mm, and it is necessary to mount two transformers for drive and receive within this area. When an ISDN pulse transformer that can be housed in this IC card is to be constructed, the conventional pot type, EI type, and EE type ferrite cores have a magnetic permeability of at most 8000 to 10000, and a high inductance at the required size. To achieve this, a huge number of turns is required, resulting in an increase in leakage inductance or an increase in capacity, so that it is very difficult and unrealistic to satisfy the required characteristics. Further, when a ring-shaped ferrite magnetic core is used, a maximum magnetic permeability of about 15,000 can be obtained, but a large number of turns is required. Assuming a trial calculation, μi = 15,000 and OR11
When a magnetic core of -3-4H is used, the minimum diameter is 49 turns with a wire of 0.05φ, which is not a realistic specification. This estimation is based on μi = 15000 MIN. It was calculated by
Considering variations in characteristics, temperature characteristics, etc., the specifications become even more stringent. In addition, the increase in the number of turns in the ring-shaped ferrite magnetic core causes the following problems. 1) Difficult work and cost increase. 2) The occurrence rate of interlayer insulation failure increases. 3) If the number of windings is only one layer, the effect on the coil height is small. 4) Increase in winding capacity. 5) Increased leakage inductance. On the other hand, the Co-based amorphous winding magnetic core has a magnetic permeability of 10,000.
Although a very high value such as 0 can be obtained, there are the following drawbacks. 1) A typical thin ring-shaped winding magnetic core has a magnetic core height of 3 mm.
However, it is difficult to manufacture a ribbon having a width narrower than that of the ribbon manufacturing and winding of the core, resulting in an increase in cost. 2) When winding a ribbon having a width of 3 mm, the height of the magnetic core varies up to about 3.5 mm because the ribbon is displaced. Furthermore, when the winding is performed in one layer on the ring-shaped magnetic core, an unnecessary space is formed in the center of the winding frame, which hinders downsizing of the coil. Therefore, it has been extremely difficult to satisfy the required characteristics and required dimensions even with the conventional Co-based amorphous winding magnetic core. The problems as described above occur, and it has been practically impossible in the past to satisfy both the height dimension and the required characteristics. The present invention, in view of the above,
ISD that satisfies both height dimensions and required characteristics and is easy to produce
An object is to provide a pulse transformer for N.

[0004]

As a result of research to solve the above-mentioned problems, it was found that both the height dimension and the required characteristics can be satisfied with the following constitution. The present invention has a plurality of pipe-shaped magnetic cores formed by winding a Co-based amorphous material having a maximum thickness of 15 μm or less, and a storage space in which two or more pipe-shaped magnetic cores are arranged adjacent to each other, and for wiring. A pulse transformer for ISND comprising a case having a terminal and a winding passing through a through hole of an adjacent pipe-shaped magnetic core arranged in the storage space, and connecting a lead wire of the winding to the wiring terminal. Is. Further, the present invention has four pipe-shaped magnetic cores formed by winding a Co-based amorphous material having a maximum thickness of 15 μm or less, and the storage spaces in which two pipe-shaped magnetic cores are arranged adjacent to each other are arranged in parallel. The pipe-shaped magnetic cores are arranged adjacent to each other in the storage space of the case having the wiring terminals, and the windings passing through the through-holes are respectively provided in the two pipe-shaped magnetic cores adjacent to each other. And a lead wire of the winding is connected to the wiring terminal.
Further, in the above structure, the winding arranged on the magnetic core in two adjacent pipes on one side is used as a drive transformer, and the winding arranged on the magnetic core in two adjacent pipes on the other side. Is the receiving transformer. The preferred dimensions of the magnetic core are an outer diameter of 4 mm or less and a length of 3
It is 0 mm or less, and more preferably an outer diameter of 2.4 to 2.
0 mm, inner diameter 1.3 to 1.7 mm, length 10 to 30 mm
Is. The magnetic core is preferably coated with a thickness of 150 μm or less, or enclosed in a case with a thickness of 0.15 mm or less for insulation. In the present invention, μ
It is preferable to use a material with e = 30,000 or more.

[0005]

According to the present invention, a pipe-shaped magnetic core is provided,
With this pipe-shaped magnetic core, a high AL value can be obtained and the number of turns can be reduced without increasing the outer diameter of the magnetic core. In addition, since the windings are formed by passing through the two through-holes around the opposite side surfaces of the two pipe-shaped magnetic cores, the windings do not appear in the outer diameter of the magnetic core, and the winding thickness The height dimension can be reduced. The outer diameter of the magnetic core is 4
If the length is 30 mm or less and the length is 30 mm or less, a coil can be obtained which satisfies the characteristics sufficiently and can be mounted. More preferably, when the outer diameter of the magnetic core is 2.4 to 2.0 mm, the inner diameter is 1.3 to 1.7 mm, and the length is 10 to 30 mm, the height of the pulse transformer is 2.8 mm MAX. And a pulse transformer with sufficient characteristics can be obtained. The above dimensions are for a case where a Co-based amorphous material is used, and it is difficult to satisfy the characteristics and dimensions with a conventional ferrite magnetic core. The reason is that with ferrite only μ = 15,000 can be obtained,
The number of turns is about 1.4 times that of the present invention, and the characteristics cannot be satisfied unless the magnetic core is increased. Also coating,
Needless to say, the case is to insulate and protect the magnetic core and insulate the coil. According to the invention,
Since the case having the space for accommodating the pipe-shaped magnetic core is used, the winding work becomes easy. For example, when winding a through hole of two pipe-shaped magnetic cores, if the magnetic core is in a twisted state, it is difficult to perform the winding work, and the coil height becomes higher than the predetermined size. Occurs,
The case of the present invention improves these. In addition, the position of the wiring terminals is set on the side surface parallel to the axial direction of the magnetic core, so the long side of the component can be used, the wiring terminals can be laid out easily, and the terminal spacing can be set wide in the actual wiring work. , Easy. The reason why the thickness of the Co-based amorphous ribbon is limited to 15 μm or less is that workability and yield in manufacturing the wound magnetic core are taken into consideration. That is, a general amorphous ribbon has a thickness of 17 to 25 μm, but the thicker the ribbon, the more difficult it is to wind the inner diameter of the magnetic core so small. The biggest problem that makes this winding difficult is breakage of the ribbon. Table 1 shows the experimental results of this ribbon thickness and ribbon breakage.
The ribbon thickness in Table 1 is the minimum thickness and the maximum thickness of each ribbon, and the number of breaks is the number of breaks when the inner diameter is 1.5 mm and the number of windings is 100.

[0006]

[Table 1]

[0007]

【Example】

Example 1 Co-based amorphous (ACO-4 material manufactured by Hitachi Metals, Ltd.)
Using the ribbon (thickness 15 μm, width 15 mm), a wound magnetic core having an outer diameter of 2.2 mm, an inner diameter of 1.5 mm and a length of 15 mm was prepared and heat-treated in a nitrogen atmosphere at 450 ° C. for 1 hour. When the characteristics of this pipe-shaped magnetic core were measured,
= 40000, and the AL value was 45.4 μH / N ^ 2.
A 80 μm-thick parylene coating was applied to this magnetic core, and 6 parallel wires were wound 8 turns using a 0.06φ wire rod to obtain a primary 16-turn and secondary 32-turn pulse transformer. A perspective view of this embodiment is shown in FIG. In FIG. 1, 1 is a magnetic core, 2 is a winding wire, and 3 is a wire rod. When the inductance at 20 kHz of this example was measured, a sufficient inductance of 23.2 mH was obtained. FIG. 2 shows a front view of the case in which the magnetic core is arranged, and FIG. 3 shows a back view of the case. The case 11 has a through hole 12 into which the pipe-shaped magnetic core 1 (shown by a broken line in the drawing) is inserted.
A plurality of wiring terminals 13 are provided on the side surface parallel to the axis of the through hole 12 so as to project from the inside of the recess 15, and the portion where the through hole 12 is provided and the wiring terminal are provided. A wiring groove 14 for passing a lead wire is formed between the wiring groove 14 and the portion provided with. This case 11
The pipe-shaped magnetic core 1 is arranged in the through hole 12 of the IS.
A pulse transformer for DN was constructed. This characteristic is as described above. In the present embodiment, the winding state and the case are separately described for convenience of description, but in the present embodiment, the case 1 described above is used.
1, the above-mentioned pipe-shaped magnetic core 1 is inserted, the above-mentioned winding is then applied, and the lead wire (the above-mentioned wire 3) of the winding is attached to the case 1
The pulse transformer is configured by connecting to the wiring terminal 13 of FIG.

Example 2 Co-based amorphous material similar to that of Example 1 (Hitachi Metals Ltd.)
Made ACO-4 material) ribbon (thickness 15μm, width 15m
m) was used as a pipe-shaped magnetic core. FIG. 4 is a front view of a case constituting the pulse transformer of this embodiment.
A back view is shown in FIG. The case 21 has a through hole 22 into which the pipe-shaped magnetic core 1 (indicated by a broken line in the figure) is inserted, and a plurality of wiring terminals 23 are recessed on a side surface side parallel to the axis of the through hole 22. A wiring groove 24 for passing a lead wire is formed between the portion provided with the through hole 22 and the portion provided with the wiring terminal 23 so as to project from the inside. There is. This through hole 22
Is formed into a shape in which two pipe-shaped magnetic cores 1 can be inserted adjacent to each other, and two magnetic cores 1 a and b are formed. The pulse transformer having the structure shown in FIG. 1 is formed in each of a and b, and the ISDN pulse transformer is formed by using a for driving and b for receiving.
In the present embodiment, the winding state and the case are described separately for convenience of explanation, but in the present embodiment, the pipe-shaped magnetic core 1 is inserted into the case 21, and then the winding is applied,
The lead wire of the winding is connected to the wiring terminal 23 of the case 21 to form the pulse transformer. Also,
The shape of the through hole of the case where the ring-shaped magnetic core is inserted is
The shape is not limited to the above. For example, FIGS.
The shape shown in FIG. The winding may be inserted into the case after the winding is applied to the magnetic core. However, when the winding is performed after inserting the magnetic core into the case, the magnetic core is fixed and the winding work is easy. Since the position of the wiring terminals is provided on the side surface parallel to the axis of the through hole, since the pipe-shaped magnetic core is used, this side surface is dimensionally long side, and the wiring terminals can be easily laid out and the terminal spacing can be improved. This is because the wiring can be set widely and the actual wiring work becomes easy. Also,
The wiring groove 24 provided between the portion in which the through hole 22 is provided and the portion in which the wiring terminal 23 is provided is designed to prevent unnecessary leakage inductance when the lead wire from the winding is laid long. In order to suppress the occurrence, it is provided so that the wiring can be concentrated. In the absence of this wiring groove, the lead wires are spread and wired, so that an air-core coil is formed, and this air-core coil causes leakage inductance.

Comparative Example 1 Mn-Zn high permeability material (GP manufactured by Hitachi Ferrite Co., Ltd.)
-11 material), outer diameter 2.2 mm, inner diameter 1.5 m
A pipe-shaped magnetic core having a length of m and a length of 15 mm was prepared. When the characteristics of this core were measured, μe = 10000, AL value 1
It was 1.4 μH / N ^ 2. 80 μm thick on this magnetic core
After applying the parylene coating of No. 1 and inserting it into a predetermined bobbin, 6 parallel wires were wound as much as possible using a wire of 0.06φ, and it was 10 turns. This was used as a transformer with primary 20 turns and secondary 40 turns. When the inductance of this transformer at 20 kHz was measured, an insufficient inductance of 9.1 mH was obtained. Table 2 shows the dimensions, the inductance, and the number of coil turns of the above-mentioned examples and comparative examples.

[0010]

[Table 2]

From Table 2, it can be seen that in the embodiment, the height is not more than 2.8 mm, the inductance is satisfied, and the number of turns is small. Further, in Comparative Example 1 using ferrite, the required characteristics could not be obtained. Further, in the above embodiment, the wire forming the primary coil is previously colored,
In the winding work and the terminal tying work, the discrimination and the work could be facilitated. Further, in the above embodiment, the insulation of the pipe-shaped magnetic core is coated, but it is desirable that the coating thickness is 150 μm or less in order to achieve thinning. Further, the insulating means is not limited to coating, and a case may be used. In this case, the thickness of the case is preferably 0.15 mm or less.

[0012]

As described above, according to the present invention, ISDN is used.
It is possible to satisfy the characteristics of the pulse transformer for use and achieve thinning, and it is also effective for simplifying the manufacturing method.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment according to the present invention.

FIG. 2 is a front view of a case according to an embodiment of the present invention.

FIG. 3 is a back view of the case of the embodiment according to the present invention.

FIG. 4 is a front view of a case according to another embodiment of the present invention.

FIG. 5 is a back view of a case according to another embodiment of the present invention.

FIG. 6 is a front view of a case according to another embodiment of the present invention.

FIG. 7 is a front view of a case of another embodiment according to the present invention.

FIG. 8 is a front view of a case according to another embodiment of the present invention.

[Explanation of symbols]

 1, 26 Magnetic core 2 Winding 3 Wire rod 11, 21 Case 12, 22 Through hole 13, 23 Wiring terminal 14, 24 Wiring groove 15, 25 Recess

Claims (3)

[Claims] 1. A wiring having a plurality of pipe-shaped magnetic cores formed by winding a Co-based amorphous material having a maximum thickness of 15 μm or less and a storage space in which two or more pipe-shaped magnetic cores are arranged adjacent to each other. A pulse transformer for ISND comprising a case having a terminal and a winding passing through a through hole of an adjacent pipe-shaped magnetic core arranged in the storage space, and connecting a lead wire of the winding to the wiring terminal. . 2. A storage space in which four pipe-shaped magnetic cores are formed by winding a Co-based amorphous material having a maximum thickness of 15 μm or less, and two pipe-shaped magnetic cores are arranged adjacent to each other in parallel. The pipe-shaped magnetic cores are arranged adjacent to each other in the storage space of the case having the wiring terminals, and the windings passing through the through-holes are respectively provided in the two pipe-shaped magnetic cores adjacent to each other. A pulse transformer for ISND, which is formed by connecting the lead wire of the winding to the wiring terminal. 3. The magnetic core according to claim 2, wherein the winding disposed on the magnetic core in two adjacent pipes on one side is used as a drive transformer, and the magnetic core is formed on two adjacent pipes in the other side. A pulse transformer for ISDN, characterized in that the winding disposed in the is a receive transformer.