JPH10223459A - High-voltage transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve the downsizing of a high-voltage transformer, and also improve the reliability. SOLUTION: In a high-voltage transformer which comprises a core 1, a bobbin 2 having a hollow 3 capable of being mounted on the core 1, and a coil 6 wound on the bobbin 2, flanges 4 and 5 are given to both ends of the bobbin 2, and at one side of the flange, a primary coil 8 is constituted of a one-turn coil consisting of a U-shaped conductor, and a terminal of the secondary coil 6 wound in single-layer winding in a row between the flanges 4 and 5 at both ends of the bobbin is wired to a secondary terminal 11, passing between the terminals of the primary coil 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-voltage transformer used for lighting a cold cathode lamp or a metal halide lamp which requires a high voltage.

[0002]

2. Description of the Related Art Heretofore, generally known as high-voltage lighting is a cold cathode lamp mounted on the back side of a liquid crystal display such as a personal computer or a word processor. Is raised to several kV, the cold cathode lamp is turned on, and the liquid crystal is displayed brightly. FIG.
FIG. 1 shows a cross-sectional view of the high-voltage transformer.
3 is a bottom view of the high-voltage transformer.

[0003] A bobbin 102 having flanges 104 and 105 at both ends and having a hollow hole 103 is provided on the bobbin 102.
A low-voltage-side primary coil 108 and a secondary-side coil 106 are wound between the primary and secondary coils 105, 105. An insulating wall 107a is provided between the primary-side coil 108 and the secondary-side coil 106. The secondary coil 106 is divided and wound by an insulating wall 107b. Then, a core 101 made of ferrite is incorporated into the hollow hole 103 of the bobbin 102 to constitute a high-voltage transformer. The terminals of the primary coil 108 and the secondary coil 106 are wired and connected to terminals 110 and 111 provided on the flanges 104 and 105, respectively.

[0004]

However, when the structure of the conventional high-voltage transformer is used for a discharge lamp or the like requiring a voltage of about 25 kV, the following problems occur. Since the voltage is higher than before, the coil potential difference in the divided winding of the secondary coil 106 becomes extremely high, and the reliability is lacking, and the number of divisions of the secondary coil needs to be increased. Becomes larger. One terminal 106a of the secondary coil 106 is wired to the secondary terminal 111 along the secondary coil 106 wound around the bobbin 102. At this time, the terminal 106a takes a longer insulation distance a than in the past. It is necessary to increase the size of the high-voltage transformer. The voltage between the terminals of the secondary coil 106 on the high voltage side is 25 kV
Therefore, it is necessary to provide a large inter-terminal distance b that does not discharge, and the size of the high-voltage transformer increases.

As described above, in the conventional high-voltage transformer structure, in order to correspond to an output voltage of 25 kV, the size of the transformer is inevitably increased. The purpose of the present invention is to provide a high-voltage transformer with improved reliability.

[0006]

SUMMARY OF THE INVENTION The present invention provides a high voltage transformer comprising a core, a bobbin having a hollow hole mountable on the core, and a coil wound on the bobbin. The primary coil is formed of at least one or more one-turn coils on one side of the flange, and one end of the secondary coil wound in a single-layer aligned winding between the flanges at both ends of the bobbin. Is a high-voltage transformer that passes between terminals of the primary coil and is wired to a secondary terminal.

In the present invention, one terminal of the secondary side coil is a high voltage transformer wired to the secondary side terminal through a wiring groove provided between the primary side terminals.

In the present invention, the core is a high-voltage transformer that is a closed magnetic circuit type core configured by combining at least two or more cores.

In the present invention, the secondary coil is a high-voltage transformer in which single-layer aligned winding coils are arranged in multiple layers, and winding start and winding end of each coil are connected to the same terminal.

In the present invention, the secondary coil has a multi-layer structure of a single-layer aligned winding coil in which multiple parallel wires are wound perpendicularly to the winding axis. These are high-voltage transformers connected to the same terminal.

According to the present invention, at least two or more bobbins provided with the coil are arranged, and a core mounted on each bobbin is inserted with a common core or different cores, and each of the secondary coils Are connected in parallel.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. Open magnetic circuit type I-type core 21
Is the hollow hole 2 of the bobbin 22 provided with the secondary coil 26
Attach to 3. The bobbin 22 has a structure in which a hollow hole 23 for inserting the core 21 is provided, and flanges 24 and 25 are provided at both ends of the bobbin 22.

The primary coil inserts a U-shaped conductor 28 into the insertion hole 27 of one flange 24 of the bobbin 22. At this time, the bobbin 22 surrounds the hollow hole 23 and the bobbin 2
2 protrudes toward the mounting surface side, and the tip thereof is the primary terminal 30.
Play a role.

The secondary coil 26 is wound in a single-layer arrangement between the flanges 24 and 25 of the bobbin 22, and the terminals 26a and 26b of the secondary coil 26 are connected to the nearby secondary terminals 31.
a, 31b.

The primary side coil is installed in the flange 24 of the bobbin 22 so that the secondary side coil 26
Alternatively, insulation is secured for the core 21.

Further, by forming the primary coil with a plurality of U-shaped conductors, for example, when three U-shaped conductors are used as the primary coil, each conductor is connected in series. For example, a three-turn primary coil can be formed, and if connected in parallel, a one-turn primary coil with reduced DC resistance and increased current capacity can be formed.

Since the secondary coil 26 is wound between the flanges 24 and 25 of the bobbin 22 in a single-layer arrangement,
For example, when the number of turns is 100 turns when the secondary coil has a voltage of 25 kV, the potential difference between the individual lines is 250 V. This potential difference of 250 V is within a range that can be guaranteed by the withstand voltage of the electric wire. For example, if an electric wire having a withstand voltage of 400 V is used, the coating of the electric wire can sufficiently assure.

On the other hand, when the conventional secondary coil shown in FIG. 12 is divided into a plurality of flanges and divided into a plurality of flanges, for example, when divided into five parts, the withstand voltage of one division is 5 kV and the withstand voltage is 5 kV. With a 400 V electric wire, it cannot be guaranteed very much. Thus, it can be seen that the single-layer aligned winding is a winding having excellent withstand voltage characteristics.

[0019] Further, the two rolled between the flanges 24, 25
The terminals 31a and 31b of the secondary coil 26 are connected to the nearby terminals 31a and 31b located at both ends of the bobbin 22, respectively, so that one of the flanges 24 of the bobbin 22 forms a low-voltage terminal. , The other flange 2
By configuring the high voltage side terminal on the 5 side, compared to the conventional case where the secondary side terminal is configured on the same flange side,
The distance c between the secondary terminals can be sufficiently increased without increasing the width of the bobbin.

For example, the reference of the insulation space distance is 1.5 k
Assuming that the output voltage on the secondary side is 25 kV, the distance between the secondary terminals must be at least 37.5 mm. In the present invention, the secondary terminals are separately installed on the flanges at both ends of the bobbin.
Since the 7.5 mm dimension is effectively utilized as a coil winding frame, the insulation distance between terminals can be increased without increasing the size of the bobbin.

However, in the conventional high-voltage transformer, since the secondary terminal is formed only on one flange side, the width of the bobbin is increased to increase the insulation distance between the terminals. Is increased.

As described above, in the present invention, the secondary coil on the high voltage side is wound in a single-layer arrangement, and the secondary terminals are arranged separately on the flanges at both ends of the bobbin. It can be seen that the characteristics are improved.

The primary terminal 30 is connected to the secondary terminal 31.
If a is located inside the bobbin, it is necessary to increase the thickness of the flange 24 to provide a terminal burying portion for the secondary terminal 31a, which is a factor of increasing the size of the bobbin and the core.
However, by providing the secondary terminal 30a outside the primary terminal 30, the overall length of the bobbin can be reduced as compared with the above.

The terminal 26a of the secondary coil 26 is connected to the secondary terminal 31a with the shortest distance by passing between the terminals 30 of the primary coil having a small potential difference. Can be reduced. The insulation resistance to the primary terminal 30 is improved by providing a wiring groove for the terminal 26a of the secondary coil 26 in the bobbin 22 in advance.

In the case of single-layer aligned winding, if the number of turns is the same, a long winding frame is required, and the transformer becomes large. However, in the present invention, by using the closed magnetic path core, the number of windings can be reduced, and the size is prevented from increasing. That is, by using a closed magnetic circuit structure for the core, a high inductance can be obtained if the windings are the same. Therefore, in order to obtain the same inductance, a closed magnetic circuit can be achieved with a smaller number of turns as compared with an open magnetic circuit structure.

In the case of a single-layer aligned winding, if a high current capacity is required or if it is desired to reduce the DC resistance, a thick wire is used. When this thick wire is used, the length of the bobbin is inevitably increased, resulting in an increase in size. As a countermeasure, by forming the single-layer aligned winding into multiple layers and connecting them in parallel, it is possible to cope with a high current capacity and a low DC resistance even with a thin wire, thereby preventing an increase in size.

In order to structure the single-layer aligned winding into a multilayer, it is possible to simply form the single-layer aligned winding into a multilayer.
Alternatively, it may be configured by winding a multi-parallel wire formed integrally with a plurality of wires in a direction perpendicular to the winding shaft.

The high-voltage transformer shown in FIG.
The DC resistance of the secondary coil is lowered by connecting the secondary coil in parallel with a circuit pattern etc.
The current capacity can be increased. Further, by using a closed magnetic circuit core such as a UU type instead of the I-shaped core,
An excellent high-voltage transformer with less leakage magnetic flux and lower DC resistance of the secondary coil.

[0029]

FIG. 1 is an exploded perspective view of an embodiment according to the present invention. This embodiment uses a closed magnetic circuit type core formed by abutting a pair of U-shaped cores 1. The core 1 has a hollow hole 3 into which a leg can be inserted, and a bobbin 2 having flanges 4 and 5 at both ends. Between the flanges 4, 5 of the bobbin 2, a secondary coil 6 is wound in a single layer in an aligned manner. The primary coil has an insertion hole 7 in one flange 4, into which an approximately one-turn coil 8 is inserted,
It is configured.

In this embodiment, the primary side coil is 0.1 mm.
Using 8φ conductor, the secondary coil is 0.2φ UEW
By winding the wire 105 turns, a voltage of 1000 V on the primary side was obtained and a voltage of 20000 V on the secondary side was obtained. The high-voltage transformer of this example could be used as a high-voltage transformer for lighting a metal halide lamp. At this time, the overall dimensions of the transformer are 20 mm × 40 mm × 25 m in height.
m high-pressure transformer could be obtained. This made it possible to construct a high-voltage transformer with a volume of about 2/3 that of the conventional product.

FIG. 2 is an explanatory view of a second embodiment according to the present invention. FIG. 2 shows a state in which two coils A and B are wound around the bobbin 2 in a single-layer arrangement. First, one coil A is single-layer aligned and wound, and another coil B is single-layer aligned and wound thereon. Then, the two single-layer aligned winding coils A,
B, as shown in the circuit diagram of FIG.
The winding ends are connected to each other to form a high-voltage transformer. By doing so, the current capacity becomes 1
The number of layers can be doubled by using two layers. At the same time, the DC resistance can be halved. In this case, the number of layers is two, but may be three or more. However, as the number of layers is increased, misalignment of aligned windings is more likely to occur, and three or less layers are desirable in terms of reliability.

FIG. 4 is an explanatory view of a third embodiment according to the present invention. In this embodiment, a parallel wire 9 in which two wires are integrally formed is used, and the parallel wire 9 is wound perpendicular to the winding axis of the coil. Thereby, the same structure as the two-layer structure of the single-layer aligned winding shown in FIG. 2 can be configured. Of course, three or more parallel lines may be used. In the case of these parallel lines, the possibility of misalignment is small and multilayering is possible.

FIG. 5 is an exploded perspective view of a fourth embodiment according to the present invention. In this embodiment, the same coil is arranged on two butting legs of a closed-loop magnetic core having a rectangular shape formed by butting a pair of U-shaped cores 1. This coil is the same as the embodiment of FIG. 1, in which a one-turn primary coil 4 is disposed on one flange 4 of a bobbin 2, and a secondary coil 4 is provided between two flanges 4, 5. Reference numeral 6 denotes a single-layer aligned winding. However, the winding directions of the two secondary coils 6 are reversed.

FIG. 6 is a bottom perspective view of the fourth embodiment. One end 6a of each secondary coil 6 wound between the flanges 4 and 5 of the bobbin 2 passes through the wiring groove 12 between the primary terminals 10 previously applied to the bobbin 2,
Connect to secondary terminal 11. By providing the wiring groove 12, wiring work and insulation resistance to the primary terminal 10 are improved.

FIG. 7 shows a circuit diagram of this embodiment. In this embodiment, the secondary side coil is connected to the same terminal, and the secondary side coil is connected to the same terminal to form a secondary side coil. For this reason, the adjacent secondary coils have the same potential, and have a structure that does not discharge even if the voltage becomes high.
Further, this secondary side coil has twice the current capacity and half the DC resistance value when arranged on only one side. Also, 1
As the secondary coil, two one-turn coils may be connected in parallel or in series.

FIG. 8 is a perspective view of a fifth embodiment according to the present invention.
Shown in In this embodiment, the cores for the bobbins around which the coils are wound are constituted by separate cores 21, respectively. The secondary coil 6 wound in a single layer between the flanges 4 and 5 is connected by a circuit pattern so as to be connected in parallel, that is, the two transformers are configured as substantially one transformer. Adjacent secondary coils 6 have the same coil specifications (number of turns, wire diameter, etc.), and the shortest adjacent secondary coils have substantially the same potential and do not cause discharge or the like. The primary-side coils 8 of one turn may be connected in series or in parallel. Further, while the winding directions of the secondary coils wound around the bobbin shown in FIG. 5 are opposite to each other, the secondary coil 6 of the present embodiment may be wound in the same direction, and the working efficiency is improved. It is to improve.

FIG. 9 is a perspective view of a sixth embodiment according to the present invention.
Shown in This embodiment is a high-voltage transformer in which a bobbin 2 provided with a coil 6 is mounted on each leg of an EE type core 13 which is a closed magnetic circuit. Two one-turn coils were arranged on one flange 4 of the bobbin 2, and the secondary coil 6 was formed by single-layer aligned winding between the flanges. In the secondary coil 6 of this transformer, at least one of the three secondary coils in the drawing is wound in a direction opposite to the winding direction of the remaining secondary coils.
This needs to be changed depending on the core shape used or the number of secondary coils.

The coil 8 composed of a one-turn coil formed on one of the flanges may be connected in series or in parallel to form a primary coil, or may be used as a pickup coil for detecting current or voltage. Alternatively, they may be used as terminals dedicated to fixing the transformer, and it is not necessary to connect them all as an electric circuit. It is not necessary to attach the primary side coil to all the insertion holes, and the primary side coil may be embedded beforehand when the bobbin is molded. It is desirable that the secondary coils have the same winding specifications so as not to cause imbalance.

The core is an I-type core as shown in FIG.
The shape is not limited to the U-type and EE-type cores, and may be any shape such as a UI-type or an EI-type. As a material of this core, a ferrite core having high pressure resistance is desirable, and Ni-Z
An n-type ferrite core is desirable.

[0040]

According to the present invention, the withstand voltage characteristic between the coils is improved by forming the secondary coil into a single layer aligned winding, and the low voltage side terminals are provided on the flanges at both ends of the bobbin.
Since the high voltage side terminals are separately arranged, the insulation distance between the terminals can be effectively utilized, and it is possible to cope with a high voltage of 25 kV without increasing the transformer shape. In addition, the use of a core with a closed magnetic circuit structure reduces the amount of magnetic flux leakage and can greatly reduce the generation of electromagnetic noise. This enables the miniaturization of high-voltage transformers and the improvement of reliability. It is possible and very useful.

[Brief description of the drawings]

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

FIG. 2 is an explanatory view of a second embodiment according to the present invention.

FIG. 3 is a circuit diagram illustrating a second embodiment according to the present invention.

FIG. 4 is an explanatory view of a third embodiment according to the present invention.

FIG. 5 is an exploded perspective view of a fourth embodiment according to the present invention.

FIG. 6 is a bottom perspective view of a fourth embodiment according to the present invention.

FIG. 7 is a circuit diagram of a fourth embodiment according to the present invention.

FIG. 8 is a perspective view of a fifth embodiment according to the present invention.

FIG. 9 is a perspective view of a sixth embodiment according to the present invention.

FIG. 10 is an exploded perspective view of the embodiment.

FIG. 11 is a bottom perspective view of the embodiment.

FIG. 12 is a sectional view of a conventional high-voltage transformer.

FIG. 13 is a bottom view of a conventional high-voltage transformer.

[Explanation of symbols]

 Reference Signs List 1 U-shaped core 2 Bobbin 3 Hollow hole 4, 5 Flange 6 Secondary coil 6a Secondary coil terminal 7 Insertion hole 8 Primary coil 9 Two parallel wires 10 Primary terminal 11 Secondary terminal 12 Wiring groove 13 EE type core

Claims (6)

[Claims] 1. A high-voltage transformer comprising a core, a bobbin having a hollow hole attachable to the core, and a coil wound around the bobbin, wherein both ends of the bobbin are provided with flanges. The primary coil is formed of at least one or more one-turn coils, and one end of the secondary coil wound in a single-layer aligned winding between the flanges at both ends of the bobbin is provided with one end of the primary coil. A high-voltage transformer, which is wired between terminals and to a secondary terminal. 2. The terminal according to claim 1, wherein one terminal of the secondary coil is wired to the secondary terminal through a wiring groove provided between the primary terminals. High voltage transformer. 3. The high voltage transformer according to claim 1, wherein the core is a closed magnetic circuit type core configured by combining at least two or more cores. 4. The secondary coil according to claim 1, wherein single-layer aligned winding coils are arranged in multiple layers, and winding start and winding end of each coil are connected to the same terminal. 2. The high-voltage transformer according to 1. 5. The secondary coil has a multilayer structure of a single-layer aligned winding coil in which multiple parallel wires are wound perpendicularly to a winding axis, and winding start and winding end of each coil are respectively set. 2. The high-voltage transformer according to claim 1, wherein the high-voltage transformer is connected to the same terminal. 6. A bobbin provided with a coil according to claim 1, wherein at least two or more bobbins are arranged, and the core mounted on each of the bobbins is a common core or a different core inserted therein. And a secondary coil connected in parallel with each other.