JP3351172B2 - Thin transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin transformer using a spiral winding used in various electronic devices.

[0002]

2. Description of the Related Art In recent years, in order to meet the technical needs of higher frequency, smaller size, thinner, and higher performance transformers, printed coil laminated transformers using print etching technology, punched coil laminated formed by punching a copper plate. Transformers having a configuration or a spiral coil laminated configuration in which electric wires are formed in a spiral shape have been developed.

[0003] However, in reality, in addition to the above technical needs, there is a strong demand for thorough cost reduction as a background of the times, and without this point, practical use has become impossible.

[0004] In order to provide a thin transformer at low cost, it is necessary to determine what kind of laminated coil and how to construct it. However, a printed coil formed by an etching method requires a large current capacity in terms of cost increase and thick film. Because a coil is formed by a punching method and a die is required for reasons such as limitations, the transformer adopts a spiral coil laminated configuration in which the electric wire is formed in a spiral shape in consideration of cost and versatility. Is increasing.

[0005] In addition, the power supply device is small and thin.
The demand for cost reduction is increasing.

Hereinafter, a conventional thin transformer using a laminated coil using a spiral winding will be described with reference to FIGS.

In FIG. 1, 1 is a magnetic core, 2 is a spiral winding,
Reference numeral 3 denotes an insulating paper, 4 denotes a primary winding, 5 denotes a secondary winding, and 6 denotes a tertiary winding.
After alternately laminating the windings 2 and the insulating paper 3 formed by spirally winding the electric wire by the coil alone to complete a laminated coil,
Magnetic core 1 constituting a closed magnetic circuit from the direction in which the coils are stacked
To complete the thin transformer body. Note that the spiral winding 2 may be a spiral punched coil manufactured by punching a thin plate conductor.

In FIG. 17, two sets of windings 2 are alternately laminated. However, if a transformer has a primary winding and a secondary winding, the same applies to two or more sets. It is. FIG. 16 shows another prior art, which is a thin transformer in which three windings 2 are stacked. FIG. 15A shows a conventional thin transformer using a spiral laminated coil, in which a primary winding 4, a secondary winding 5, and a tertiary winding 6 are laminated while sandwiching the insulating paper 3. It was done.

FIG. 15B shows an example of a power supply circuit using the thin transformer of FIG.
, A control circuit 9 is connected to the tertiary winding 6 via a rectifying and smoothing circuit of a diode 10 and a capacitor 11, and the output of the control circuit 9 outputs the other end of the primary winding 4. Is turned on and off to drive the primary side. A load 14 is connected to the secondary winding 5 via a rectifying and smoothing circuit including a diode 12 and a capacitor 13.

[0010]

However, FIG.
In the case of using the spiral laminated coil shown in FIG.
The secondary winding 4, the secondary winding 5, and the tertiary winding 6 are each formed by using an electric wire having a circular cross section and are formed in a spiral shape. ,
The thickness direction of the wire varies, and quality loss including electric performance occurs. In addition, when the current becomes large, the wire diameter becomes large, which hinders miniaturization and thinning. Furthermore, when the transformer is driven at high frequency, the phenomenon that the AC resistance increases due to the skin effect occurs, resulting in an increase in loss and high efficiency. Hinders the transformation.

In order to solve this problem, print etching or a thin-plate laminated coil is used as a high-frequency drive coil by punching a thin-plate conductor. However, in print etching, cost and versatility are reduced as described above. Not appropriate. Further, even if a thin plate-shaped conductor is manufactured using a spiral-shaped punched coil manufactured by a punching method, preparing a wide variety of punching dies causes an increase in production cost.

The number of times of turning on and off the primary switching element (FET) 8 shown in FIG. 15B is called a switching drive frequency.
00 kHz is the current industry standard. This power supply is downsized,
Technology development for increasing the driving frequency of a power supply has been studied in order to reduce the thickness and improve the performance.

However, in reality, since the power supply is driven at a high frequency, a thin transformer is expensive if it is manufactured using the above-described print etching coil or punching coil.
Due to cost and versatility issues, it is not widely used. To commercialize and spread the use of high-frequency driving of power supplies, low-cost and versatile high-frequency compatible components are required, and the key component is said to be a transformer.

The present invention solves the above-mentioned problems, and uses a laminated coil that is low in quality loss including electric performance using a spiral winding, is versatile, and has low loss and is compatible with high frequencies. An object is to provide a thin transformer.

[0015]

In order to solve the above problems, a thin transformer according to the present invention comprises a primary winding, a secondary winding,
Form a closed magnetic circuit by incorporating it into the primary winding and the secondary winding
And a small number of the primary winding and the secondary winding.
At least one of them has a self-fusion layer and an insulating coating layer.
The flat rectangular cross-section of the electric wire
Wound in one layer so that it is flat in the direction,
At least one of the secondary windings is divided into windings
The primary winding and the secondary winding are connected in parallel or in series.
All of the wire is formed as a single layer with almost the same winding width.
The primary winding and the secondary winding are alternately stacked so as to face each other.
Thin type with a magnetic core built in from the direction in which the wires are stacked
In the lance, the primary winding and the secondary winding are electrically connected to each other.
The flow direction is opposite to each other, and the electric wire is made of copper
And the upper limit (f) of the driving frequency of the power supply and the thickness of the electric wire.
Acquire _{(to), 0.3mm> t o} ≒ 3 × δ (mm) (δ: skin thickness, the copper δ = 66.1 / √f (mm) ) is obtained is characterized in that a.

[0016]

According to the above construction, the space between the wires can be eliminated and the space utilization factor can be improved, so that the space factor of the windings can be improved, the thickness of the windings can be reduced, and the primary and secondary facing areas can be increased. Is formed to prevent the AC resistance from increasing due to the skin effect, the coupling between the primary and secondary windings is strengthened, and the loss at high frequencies can be reduced. In addition, since the cross-sectional area can be varied even when the thickness of the wire is unified, the thickness can be standardized, and variations in production and performance can be reduced. Furthermore, since the shape can be maintained by the coil alone, handling becomes easy,
A thin coil can be easily manufactured by a winding method.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) Hereinafter, a first embodiment which is an embodiment of a thin transformer according to the present invention will be described with reference to FIGS. To be more specific, reference numerals 4a and 4b denote primary split windings, and reference numerals 5a and 5b denote secondary split windings, each of which comprises a spiral winding 2a formed of a flat wire.

Next, the structure will be described in more detail.
As shown in FIG. 2, a rectangular wire with a self-fusing layer and a rectangular cross-section with an insulating coating layer is formed into a spiral in a single layer, almost in the same area and in close contact so as to be flat in the longitudinal direction of the cross-sectional shape. Meanwhile, the shape is fixed by using the fusion layer to prepare the primary divided windings 4a, 4b and the secondary winding 5, and further, FIG.
As shown in (a), the windings of the respective layers are alternately stacked so as to face each other while the insulating paper 3 is inserted between the layers, thereby completing a laminated coil. From the direction in which the coils are stacked, the thin transformer is completed by incorporating the magnetic core 1 constituting the closed magnetic circuit in the same manner as in the prior art of FIG. The connection of the laminated coils in the present embodiment may be performed by connecting the primary windings 4a and 4b divided as shown in FIGS. 1B and 1C in parallel or in series.

According to the above construction, since a wire having a rectangular cross section with an insulating coating layer is used, a space gap is smaller than that of a conventional wire having a circular cross section, and a coil manufactured by etching. In addition, there is no need for a gap between wires as in the case of a stamped thin plate coil. In addition, an electric wire having a rectangular cross section is formed in a single layer so as to be flat in the longitudinal direction, and is formed in a spiral shape in the same area and in close contact with each other. Primary windings 4a and 4b divided in parallel or in series, the thickness of the windings is thin and
The facing area between the primary and secondary is large, and the distance between the primary and secondary can be formed to be small. As a result, an increase in AC resistance due to the skin effect of the wire due to the high frequency can be prevented, and
Since the coupling between the windings in the next stage becomes strong, low loss at high frequencies is realized.

Further, since the wire having a rectangular cross section is wound so as to be flat in the longitudinal direction, the cross-sectional area can be varied even if the thickness of the wire is unified, and the wire having a variety of current capacities can be formed. The thickness can be standardized, and variations in production and performance can be reduced.

In addition, the surface pressure at the cross section between the rectangular wire drawing portion 2b and the winding in the rectangular wire drawing portion 2b can be reduced, and the reliability is improved. In addition, since the electric wire with the self-fusing layer is used, the shape of the coil alone can be maintained, so that the handling in the post-process is easy, and the thin coil can be easily manufactured by the winding method.

In the above description, only the primary winding is divided. However, as shown in FIG. 3A, the secondary winding is also divided to form secondary divided windings 5a and 5b. By connecting the secondary side in parallel or in series as in b) and (c), the coupling between the primary and secondary windings can be further increased, so that the loss at high frequencies can be further reduced. .

FIGS. 4 (a) and 4 (b) show another example of a wire having a rectangular cross section used in the present invention, in which the relationship between the dimension B and the dimension A is B ≧ A. Then, even if it is an ellipse or an ellipse, the effect is the same.

In this embodiment, a method of manufacturing a spiral coil for forming a single coil is not described. However, after spirally winding using an insulated wire, an adhesive, It may be manufactured by fixing with a fusion material, a resin or the like so that the shape can be maintained.

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

Basically, in FIG.
7, the same components as those in FIGS. 1 to 4 are denoted by the same reference numerals, and a detailed description thereof will be omitted. FIGS. 5 (a) and 5 (b)
1 is different from FIG. 1 in that a primary auxiliary winding called a tertiary winding 6 is an upper layer of the primary divided winding 4a in FIG.
In FIG. 5 (b), it is provided on the same layer as the primary split winding 4a and with the same thickness as the other spiral windings. FIG. 5 (c)
FIG. 15 shows a power supply circuit using the thin transformer of this embodiment.
The configuration is the same as that of the circuit of FIG.

According to the above configuration, the thickness can be the same even if the cross-sectional area of the tertiary winding 6 is different from that of the primary or secondary winding. At the same time, since the coupling with other windings is also stabilized, a unique effect that the control performance is also stabilized can be obtained.

Embodiment 3 Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a cross-sectional view of the laminated coil of the thin transformer, and the same parts as those of the embodiment of FIG.

FIG. 7 is an experimental result showing the relationship between the AC resistance increase rate and the driving frequency in the transformer assembly state (solid line) and the coil single state (dashed line). Shows a tendency to increase as the value increases. This is due to the thickness of the material, the skin effect (current flows intensively on the surface of the wire at high frequencies, and the actual AC resistance increases. This current distribution bias phenomenon) and the proximity of the wire. This is caused by a proximity effect (a phenomenon in which current flows in the same direction and the current distribution is biased outward when two conductors come close to each other). Originally, if the coil itself was used, the AC resistance increase rate would increase due to the skin effect and the proximity effect. However, as shown in FIG. The rate of increase of the AC resistance is smaller than that of the single unit.

The reason for this is that currents flowing in opposite directions flow through the primary winding and the secondary winding, so that the current distribution becomes more uniform, the AC resistance is reduced, and the magnetic core is incorporated. This is because the degree of magnetic influence increases when the transformer is assembled, and this tendency is strengthened. This phenomenon is a phenomenon in which the proximity effect acts in the transformer assembling state to suppress an increase in the AC resistance, and this phenomenon is hereinafter referred to as a cancel effect.

From the above phenomena, the following considerations and experiments were conducted.

(1) Setting of Effective Means for Improving Coupling of Windings (Consideration of Winding Configuration) (2) Considering compatibility between setting of upper limit f of driving frequency in power supply and setting of optimum thickness t ₀ of winding. Then, when the rate of increase in the AC resistance of the transformer is equal to or lower than a specific frequency, the canceling effect is effectively used to reduce the rate of increase in the AC resistance of the transformer, thereby providing a low-loss transformer.

In order to further confirm the above considerations, the relationship between the AC resistance increase rate and the frequency at each thickness similar to that in FIG. 7 was obtained while varying the thickness t of the winding in the laminated coil having the basic configuration as shown in FIG. And the occurrence frequency A of the cancel effect was obtained.

In this experiment, as means for enhancing the coupling of the windings described in the above-mentioned consideration (1), the primary divided windings 4a and 4b and the secondary windings are alternately laminated.

The results of the above experiments are shown in Table 1.

[0036]

[Table 1]

According to Table 1, when the winding thickness is 0.3 mm,
No cancellation effect occurs. When the winding thickness is 0.2 mm, a canceling effect occurs at a frequency of 400 to 900 kHz or less. The smaller the thickness, the higher the occurrence frequency A of the canceling effect. The occurrence frequency A of the canceling effect is 1.5 to 2.86 times the skin thickness δ of copper at the frequency A. This indicates that if the thickness of the winding is approximately three times the skin thickness δ, the canceling effect occurs at a frequency near the thickness.

In conclusion, if the upper limit value of the driving frequency of the power supply is set to about three times the skin thickness δ of copper at that frequency, the canceling effect can be used, so that the AC resistance can be reduced and standardized at the same time. It could be confirmed.

From this, if an effective means for increasing the coupling of the windings is provided, the optimum thickness condition t ₀ of the winding when using copper as a wire at the time of assembling the transformer is: 0.3 mm> t ₀ ≒ 3 × δ where δ: skin thickness, δ = 66.1 / √f (m
m) f: The upper limit (Hz) of the drive frequency of the power supply may be set.

As described above, according to the configuration of this embodiment,
(1) setting of effective means for increasing the coupling of the windings, and (2)
The upper limit f of the driving frequency in the power supply and the optimum thickness t _{0 of the} winding.
Since both of the setting conditions are satisfied, the reduction of AC resistance and standardization can be achieved at the same time, drastic reduction of loss at the time of transformer assembly, effective use of wire material, and new standardization that can be optimized. The effect is from Example 1
In addition to the effects of 2, the transformer can be made smaller and less expensive.

It is easy to think that the optimum thickness condition t ₀ of the winding when copper is not used as the wire is also determined by t ₀ 03 × δ. You can use this idea.

When the upper limit of the driving frequency is approximately 1 MHz when the wire is copper, the skin thickness δ at 1 MHz is 66
Since μ = 0.066 mm, it is about 0.3 times as large as about three times.
About 2 mm is the optimum thickness.

If the upper limit of the driving frequency is approximately 5 MHz, the skin thickness at 5 MHz is δ = 30 μ = 0.030
mm, it can be said that the optimum thickness is about 0.1 mm, which is about three times.

Embodiment 4 Hereinafter, a fourth embodiment of the present invention will be described with reference to FIGS. 9 (a) and 9 (b).

In the drawing, reference numerals 15a and 15b denote thin plate-shaped punched coils. In the present embodiment, the coils 15a and 15b formed by punching a thin conductive plate are primary and secondary coils.
A laminated coil is formed by using one of the secondary windings.

According to the present embodiment, since the sheet-like punched coils 15a and 15b are used for one of the primary and secondary windings, spiral winding cannot be performed by the winding method. In addition to the effects of the above-described first to third embodiments, a unique effect that the region can cope with a large current and thus can cope with a wider range of electric specifications can be obtained.

Embodiment 5 Hereinafter, a fifth embodiment of the present invention will be described with reference to FIGS. 10 (a) and 10 (b).

In this embodiment, as shown in FIG. 10 (a), a thin conductive plate having substantially the same winding width as the primary windings 4a, 4b and the secondary winding 5 is used as a one-turn coil 15a for the primary and secondary windings. It is inserted into at least one of the layers of the next winding, and as shown in the power supply circuit diagram of FIG. 10B, one lead end of the one-turn coil 15a is connected to the ground of the power supply circuit. One drawer end is open.
Here, the connection between the one lead end and the power supply circuit may not be ground as long as it has a stable potential.

As described above, according to this embodiment, the primary and secondary electrostatic shielding can be easily performed even in the lamination method, and the new effect that the noise can be reduced can be obtained in addition to the effects of the first to fourth embodiments. Obtained.

The one-turn coil 15 used here
Regarding a, a print coil by etching may be used.

Embodiment 6 Hereinafter, a sixth embodiment of the present invention will be described with reference to FIG.

As shown in the figure, the primary windings 4a, 4b and 2
A coil 2a in which a wire having a rectangular cross section with a self-fusing layer and an insulating coating layer having substantially the same winding width as the secondary winding 5 is spirally wound in one layer so as to be flat in the longitudinal direction of the cross section of the wire. Is inserted in at least one of the layers of the primary and secondary windings, one of the leading ends is connected to a stable potential of the power supply circuit, and the other leading end is opened.

As described above, according to the present embodiment, it is possible to form the electrostatic shielding coil in the same manufacturing process as the other spiral coils, and to obtain the specific effects of reducing noise.
4 is obtained in addition to the effect.

Embodiment 7 Hereinafter, a seventh embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

In the same figure, 4a _R and 4b _R are right magnetic leg primary windings, 5 _R are right magnetic leg secondary windings, 4a _L and 4b _L are left magnetic leg primary windings, and 5 _L are left magnetic legs. The leg secondary winding is shown.

In this embodiment, as shown in FIG. 12A, a UU-shaped magnetic core 1a is formed by using two sets of laminated coils of the present invention.
Is incorporated in each of the laminated coils.

FIGS. 12B and 12C show connection examples.
As shown in FIGS. 13A and 13B, there is a method of connecting the respective coils in series or in parallel, and other connection methods may be used.

As described above, according to the present embodiment, the UU type magnetic core 1a
Are located in the laminated coil, that is, have a core-type structure, so that noise interference to external power supply circuits and devices due to leakage magnetic flux from the butted portion can be reduced. Further, in the case of a structure having a magnetic gap at the abutting portion of the UU-shaped magnetic core 1a, a split gap configuration is provided in which the magnetic gap can be divided into two right and left magnetic legs, and an increase in coil loss due to magnetic flux leakage from the magnetic gap can be reduced. Is obtained in addition to the effects of the first to sixth embodiments.

Embodiment 8 Hereinafter, an eighth embodiment of the present invention will be described with reference to FIG.

FIG. 14 is an external view of a spiral winding and insulating paper showing an eighth embodiment of the present invention. Eighth Embodiment
13 is applicable to the case where the left and right windings are connected in series as shown in the primary side connection diagram of FIG. 13 (a) or FIG. 13 (b). As shown in FIG. The left and right continuous spiral winding 2c formed by continuously forming the windings inserted into the legs.

According to the present embodiment, in addition to the effect of the seventh embodiment, since connection of the left and right coils is not required, there is a new effect that the number of connection steps of the laminated coil can be reduced.

[0062]

As described above, according to the present invention, the primary winding,
Form a closed magnetic circuit by incorporating the secondary winding, primary winding and secondary winding
And at least one of a primary winding and a secondary winding.
Either one has a cross section having a self-fusion layer and an insulating coating layer.
Flatten a flat wire in the longitudinal direction of the flat wire cross section.
So that the primary and secondary windings are
At least one of the windings is divided and connected in parallel or in series.
And the primary and secondary windings are all single-layer wound and
Formed in the same winding width, alternately laminated so as to face each other,
Assemble magnetic core from the direction in which primary winding and secondary winding are stacked
Primary and secondary windings
Means that the directions of current flow are opposite to each other,
The upper limit (f) of the driving frequency of the power supply and the thickness of the electric wire
Learn _{(to), 0.3mm> t o} ≒ 3 × δ (mm): Since (δ skin thickness, the copper δ = 66.1 / √f (mm) ) was set to (1) winding occupancy Can be improved.

(2) Low loss can be realized at high frequency.

(3) The thickness can be standardized, and variations in production and performance can be reduced.

(4) The surface pressure at the crossing portion between the lead portion and the winding can be reduced, and the reliability is improved.

(5) A thin coil can be easily formed by the winding method.

Further, in the case where the primary or secondary auxiliary winding is additionally formed with the same thickness as the other spiral windings, (6) there is no step at the time of laminating the coils, so that the manufacturing quality is improved. Becomes stable.

(7) Since the coupling is stabilized, the control performance is also stabilized.

Further, copper is used as an electric wire material of each layer,
The upper limit of the driving frequency of the power supply is f, δ is the skin thickness, δ = 66.1 / √f (mm) for copper, and the thickness t _{0 of the} winding is 0.
In the case where 3 mm> t ₀ ≒ 3 × δ (mm), (8) When assembling the transformer, the loss can be significantly reduced and the amount of wire rod can be effectively used.

(9) Standardized optimal design is also possible.

Further, in the case where a coil formed by punching a thin conductive plate is used for one of primary and secondary windings to form a laminated coil, (10) large current handling is possible. It is possible and can correspond to a wider range of electrical specifications.

Further, a thin conductive plate having substantially the same winding width as the primary winding and the secondary winding is inserted into at least one of the layers of the primary and secondary windings as a one-turn coil. In a configuration in which one lead end of the turn coil is connected to the ground of the power supply circuit and the other lead end is open, (11) low noise can be achieved.

Further, an electric wire having a substantially same winding width as that of the primary winding and the secondary winding and having a self-fusing layer and an insulating coating layer and having a rectangular cross section is flattened in the longitudinal direction of the cross section of the electric wire. Like
A coil wound in one layer in a spiral shape is inserted into at least one of the layers of the primary and secondary windings, one of the drawn ends is connected to a stable potential of the power supply circuit, and the other drawn end is opened. (12) A coil for electrostatic shielding can be formed in the same manufacturing process as other spiral coils, thereby reducing the number of manufacturing steps and achieving low noise. .

Further, in a configuration in which two sets of laminated coils are used and the UU-shaped magnetic core 1a is incorporated in each laminated coil, (13) noise disturbance to external power supply circuits and devices can be reduced. .

(14) The loss of the coil due to the magnetic flux leaking from the magnetic gap can be reduced.

Further, in the configuration in which the windings inserted into the left and right magnetic legs are formed continuously, (15) the number of steps for connecting the laminated coils can be reduced.

As described above, according to the present invention, it is possible to provide a low-cost, low-loss, low-frequency, high-frequency-compatible laminated transformer with a low quality loss including electric performance.

By using the thin transformer of the present invention for a power supply, (16) it is possible to provide a power supply that can be differentiated by reducing cost and thickness. This has a great effect, and is of great industrial value.

[Brief description of the drawings]

FIG. 1A is a sectional view of a laminated coil according to a first embodiment which is an embodiment of the thin transformer of the present invention. FIG.

FIG. 2 is a perspective view of a spiral coil which is a main part of the coil.

FIG. 3A is a cross-sectional view of another embodiment of the laminated coil, which is the main part of the embodiment; FIG.

FIG. 4 (a) is a cross-sectional view of another embodiment of the electric wire having a rectangular cross section which is the main part. (B) is a cross-sectional view of another embodiment of the electric wire having a rectangular cross section which is the main part.

5A is a sectional view of a laminated coil which is a main part of the thin transformer of the second embodiment. FIG. 5B is a cross-sectional view of a laminated coil which is a main part of the thin transformer of the second embodiment. (C) Circuit diagram of power supply circuit using second embodiment

FIG. 6 is a sectional view of a laminated coil which is a main part of the third embodiment.

FIG. 7 is an explanatory diagram showing a relationship between a frequency and an AC resistance increase rate for explaining the cancel effect.

FIG. 8 is a cross-sectional view of the laminated coil as the main part.

FIG. 9A is a plan view of a thin plate coil as a main part of the fourth embodiment. FIG. 9B is a plan view of a thin plate coil as a main part of the fourth embodiment.

FIG. 10A is a sectional view of a laminated coil which is a main part of the fifth embodiment. FIG. 10B is a connection diagram of a power supply circuit using the fifth embodiment.

FIG. 11 is a sectional view of a laminated coil which is a main part of the sixth embodiment.

12A is a sectional view of the seventh embodiment, FIG. 12B is a connection diagram of the seventh embodiment, and FIG.

FIG. 13 (a) Another connection diagram of the seventh embodiment (b) Another connection diagram of the seventh embodiment

FIG. 14 is a perspective view of a spiral winding and insulating paper which are main parts of the eighth embodiment.

15A is a cross-sectional view of a spiral laminated coil which is a main part of a conventional thin transformer, and FIG. 15B is a circuit diagram of a power supply circuit using the thin transformer.

FIG. 16 is a sectional view of the same.

FIG. 17 is an exploded perspective view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic core 1a UU-shaped magnetic core 2 Spiral winding 2a Spiral winding using a flat wire 2b Flat wire draw-out part 2c Spiral winding forming a left-right continuous formation 3 Insulating paper 4 Primary winding 4a Primary split winding 4b 1 Secondary winding 5 Secondary winding 5a Secondary winding 5b Secondary winding 6 Tertiary winding 7 Input power supply

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-21244 (JP, A) JP-A-4-133408 (JP, A) JP-A-6-314626 (JP, A) 166913 (JP, A) Japanese Utility Model 7-3120 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01F 27/28 H01F 30/00 H01F 5/00

Claims (7)

(57) [Claims] 1. A primary winding, a secondary winding, and the primary winding
And a magnetic core which is incorporated in the secondary winding to form a closed magnetic circuit.
At least one of the primary winding and the secondary winding
One is a rectangular cross section having a self-fusing layer and an insulating coating layer.
Flat wire in the longitudinal direction of a rectangular cross section of the wire
The primary winding and the secondary winding
At least one of them is divided winding and connected in parallel or
Are connected in series, and all of the primary winding and the secondary winding are
One-layer winding with almost the same winding width and face-to-face
Alternately stacked, the primary winding and the secondary winding were stacked
A thin transformer smell that incorporates a magnetic core from different directions
Therefore, the primary winding and the secondary winding
Directions are opposite to each other, the wire is made of copper,
Upper limit (f) of drive frequency and thickness (to) of the electric wire
_{The, 0.3mm> t o ≒ 3 ×} δ (mm) (δ: skin thickness, the copper δ = 66.1 / √f (mm) ) and the thin transformer. 2. The thin transformer according to claim 1, wherein the primary or secondary auxiliary winding is additionally formed with the same thickness as other spiral windings. 3. A core formed by punching a thin conductive plate.
In which the coil is used for one of the primary and secondary windings.
3. The thin transformer according to 1 or 2 . 4. A thin plate having substantially the same winding width as the primary and secondary windings
Each layer of primary and secondary windings with the conductive plate of 1 turn coil
Inserted into at least one of them, and a one-turn coil
Of the power supply circuit to a stable potential
4. The method according to claim 1, wherein one of the drawer ends is open.
The described thin transformer. 5. Self-fusing with substantially the same winding width as the primary and secondary windings
A wire with a rectangular cross section with a coating layer and an insulating coating layer,
Spiral 1 so that it becomes flat in the longitudinal direction of the cross section of the wire
At least between the layers of the primary and secondary windings
Insert one of them into the power circuit
Connect to stable potential and open the other end
Item 3. The thin transformer according to item 1, 2 or 3 . 6. A UU-shaped magnetic core using two sets of laminated coils.
Is incorporated in each of the laminated coils.
Is the thin transformer according to 2 or 3 or 4 or 5 . 7. The windings inserted into the left and right magnetic legs are continuously formed.
7. The thin transformer according to claim 6, wherein the transformer is formed.