JPH06333759A - Printed coil-type transformer - Google Patents

Abstract

PURPOSE:To provide a small printed coil-type transformer with a larger number of turns without requiring strict accuracy in outer dimension of a plate coil in manufacturing. CONSTITUTION:In a printed coil-typed transformer, a primary coil 10 and a secondary coil 20, each having a spiral conductor pattern, are piled up, and a core 30 is passed through a central part of the primary and secondary coil patterns. In addition, a plurality of conductive spiral patterns as the primary coil and a plurality of conductive spiral patterns as the secondary coil are formed on each primary or secondary coil face, and the central parts of these conductive patterns are connected with a magnetic path of the core.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed coil type transformer suitable for use in electronic equipment and power supply devices, and more particularly to improvements to achieve miniaturization and high performance of the transformer.

[0002]

2. Description of the Related Art A transformer in which windings are laminated is disclosed in, for example, Japanese Patent Application No. 5-73459 proposed by the present applicant. FIG. 5 is a circuit diagram of the transformer. In the figure, a direct current is supplied to the primary winding Prm, and the primary winding Prm is turned on / off by a switching element such as an FET (not shown). When a commercial AC power supply is used as an input, it is converted to DC by a rectifying / smoothing circuit, but the winding ratio is determined so that the input voltage is as high as about 100V and the voltage is required on the secondary side. Two secondary windings Sec are provided, one for output voltage of 5V and the other for output voltage of 12V.

FIG. 6 is a perspective view showing the construction of a print coil type transformer. The core 30 is a so-called EE type core,
It has a middle foot core 32 in the center and two leg cores 34 on both sides thereof. The primary coil 10 has a role as the primary winding Prm, and has a spiral conductor pattern 12 corresponding to the winding and a core insertion hole 14 through which the middle leg core 32 penetrates. The secondary coil 20 serves as the secondary winding Sec, and has a spiral conductor pattern 22 corresponding to the winding and a core insertion hole 24 through which the middle leg core 32 penetrates. Since the primary coil 10 and the secondary coil 20 are laminated and surrounded by the core 30, electromagnetic coupling as a transformer is good. The primary side coil 10 and the secondary side coil 20 having these conductor patterns are called flat plate coils, and several flat plate coils are laminated due to the current flowing through the transformer and the number of turns of the conductive pattern that can be formed on the flat plate coil on one side. ing.

[0004]

However, in order to increase the number of turns of the coil, either increase the number of laminated flat coils or increase the outer size of the flat coils. There was a problem that the transformer was upsized and the manufacturing cost was increased. Also,
Although the flat coil is housed in both legs of the EE-shaped core, if the dimensional control of the flat coil is incorrect, the flat coil cannot collide with each other and cannot be assembled properly. Therefore, in order to maintain the dimensional accuracy of the flat coil, when adopting the work procedure of forming the flat coil on one surface and separating the flat coil, it is not possible to use an inexpensive processing means such as push-cutting, and the machining However, there is a problem that the amount of material is increased and the amount of material is reduced. The present invention has solved the above-mentioned problems, and an object of the present invention is to provide a small-sized printed coil type transformer capable of achieving a large number of coil turns and a rough outer shape machining accuracy of a flat plate coil.

[0005]

SUMMARY OF THE INVENTION The present invention to achieve such an object is to stack a primary side coil 10 and a secondary side coil 20 having a spiral conductor pattern, and to stack these primary side coil and secondary side coil. In a printed coil type transformer having a core 30 penetrating the center of the conductor pattern of the side coil, a plurality of spiral conductor patterns of the primary side coil and the secondary side coil are formed on each coil surface,
It is characterized in that the central portions of the conductor patterns of these coils are connected by a magnetic path by the core.

[0006]

Since a plurality of conductor patterns are provided on one surface of each coil, a substantial number of windings can be secured even if the number of laminated coils is small. Since the core penetrates through the central portion of each conductor pattern to form a closed magnetic circuit, magnetic coupling between the coil regions is improved, power can be efficiently transmitted, and this is preferable as a transformer.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. Figure 1
FIG. 3 is a perspective view showing the configuration of an embodiment of the present invention. In the figure, the primary coil 10 and the secondary coil 20 have a first coil region A corresponding to the conductor patterns 12a and 22a,
The second coil region B corresponding to the conductor patterns 12b and 22b is provided, and both are substantially bisected. In the first coil area A, the penetrating portion 36a of the core 30 penetrates through the central portions of the conductor patterns 12a and 22a, and the second coil area B is formed.
Then, the core 30 is formed at the center of the conductor patterns 12b and 22b.
The penetrating portion 36b of is penetrated. Here, the core 30 constitutes a closed magnetic circuit that connects the through portions 36a and 36b. Further, although the first coil region A and the second coil region B have conductor patterns of substantially the same shape, in the case of a step-down transformer, the conductor patterns 12a and 12b of the primary side coil 10 are outside the flat coil. Connected in series with
Regarding the secondary coil 20, conductor patterns 22a, 22
b are connected in parallel.

According to this structure, since the first coil area A and the second coil area B can be used as the coil winding area with one flat plate coil, the flat plate coil can be used as compared with the conventional one-sided one-coil type. The number of laminated coils is half. In this case, since the total number of windings is the same, the electrical characteristics are equivalent to those of the conventional flat-plate coil laminated, but the surface area is doubled, so that the thermal characteristics are improved. is there.

A comparison of coil areas is as follows. In the conventional type, the coil area Ac has the following value. Ac = π (a + nw) ² = π (a ² + 2anw + n ² w ² ) (1) where a is the inner diameter of the coil, n is the number of coil turns, and w is the winding width of the coil. On the other hand, in the present embodiment, the coil area Ac has the following value. Ac = 2xπ (a + nw / 2) 2 = π (2a 2 + 2anw + n 2 w 2/2) (2) That is, when the 1.4xa / w <n is less towards the present embodiment as compared with the conventional type Only the coil area is required, and the ratio gradually approaches 1/2. In this embodiment, the geometric shapes of the coil regions are the same so that the coil area is effectively used.

Now, the coil resistance will be described. In the conventional type, the average coil diameter Rm and the coil length Lc are as follows. Rm = a + nw / 2 (3) Lc = 2πxnx (a + nw / 2) (4) On the other hand, in the present embodiment, the average coil diameter Rm and the coil length Lc are expressed by the following equations. Rm = a + nw / 4 (5) Lc = 2πx2x1 / 2xnx (a + nw / 4) (6) Since the coil resistance is proportional to the coil length Lc, this embodiment has a smaller resistance value than the conventional type. The ratio asymptotically approaches 1/2.

Further, in this embodiment, the core 30 has a penetrating portion 36.
Only a closed magnetic path that connects a and 36b is formed, and no magnetic path is formed outside the flat coil. Therefore, there is an effect that the outer peripheral machining accuracy of the flat plate coil is low, and the coil can be separated by an inexpensive means such as push cutting. Further, there is also an effect that the whitening of the processing is reduced and the material removal is improved.

FIG. 2 is a structural perspective view showing a second embodiment of the present invention. Here, the secondary side output voltage is 5V and 12V.
Since there are various types, the two spiral patterns of the secondary coil 20 are provided independently of each other, and the number of turns thereof is also determined according to the output voltage. In addition, the primary coil 1
Zero is divided corresponding to two secondary windings. With this configuration, both 5V and 12V coils have the same magnetic coupling with the primary coil 10, and there is an effect that power transmission can be performed efficiently. Also, 5V and 12V
When the electric power of both coils is unbalanced, the number of turns of the primary coil 10 may be distributed according to the electric power.

FIG. 3 is a perspective view showing the structure of a third embodiment of the present invention. Here, three positions, that is, a first coil region A, a second coil region B, and a third coil region C are formed on one flat plate coil. The core 30 has three arms so as to magnetically connect these three regions. Further, in the primary side coil 10, each primary winding is equally divided into three regions and connected in series outside the coil region. Further, the secondary coil 20 can obtain three independent outputs by using each coil region independently.
The total of the primary side coil 10 and the secondary side coil 20 is 3
Although it is a layer, it does not matter if it is two layers. With such a configuration, a large number of independent secondary windings can be secured in the secondary coil 20, and it is suitable when a large number of independent secondary windings are required as in a multi-output power supply. .

FIG. 4 is a constitutional perspective view showing a fourth embodiment of the present invention. In this case, one flat plate coil has four positions, that is, the first coil region A, the second coil region B, and the third coil region C.
In addition, the fourth coil region D is formed. The core 30 is divided into two, one core 30a magnetically connects the first coil region A and the second coil region B, and the other core 30b is the third coil region C and the fourth coil region D. Are magnetically linked. The windings of each coil are connected outside each coil region. In this way,
It is equivalent to a transformer divided into two and electrically connected to the outside.

[0015]

As described above, according to the present invention, a plurality of spiral conductor patterns of the primary side coil and the secondary side coil are provided for each coil surface and are connected by the magnetic path by the core. Even if the number of laminated layers is reduced as compared with the conventional one, the required number of windings can be secured, and the size of the transformer can be reduced. Further, in the same flat coil, the primary winding or the secondary winding is formed depending on whether the flat coil is assigned to the primary side coil or the secondary side coil. This also has the effect of facilitating external electrical connection and reducing the size of the entire coil. In addition, since the conductor patterns have the same width in the same flat coil, there is an effect that the coil can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a configuration perspective view showing an embodiment of the present invention.

FIG. 2 is a configuration perspective view showing a second embodiment of the present invention.

FIG. 3 is a configuration perspective view showing a third embodiment of the present invention.

FIG. 4 is a configuration perspective view showing a fourth embodiment of the present invention.

FIG. 5 is a circuit diagram of a transformer.

FIG. 6 is a configuration perspective view of a print coil type transformer.

[Explanation of symbols]

 10 primary coil 20 secondary coil 30 core

Claims (1)

[Claims] 1. A primary side coil (10) and a secondary side coil (20) having a spiral conductor pattern are laminated and penetrated through the central portions of the conductor patterns of the primary side coil and the secondary side coil. In a printed coil type transformer having a core (30), a plurality of spiral conductor patterns of the primary side coil and the secondary side coil are formed on each coil surface, and the central portion of the conductor pattern of each coil is defined as above. A printed coil type transformer characterized by being connected by a magnetic path by a core.