JP2001223120A - Thin transformer - Google Patents

Abstract

(57) [Problem] To eliminate the limitation that the height of a block-shaped closed magnetic circuit core in a conventional transformer becomes higher than a certain value, and to eliminate a decrease in material yield in the case of a core such as a laminated silicon steel sheet. Another object of the present invention is to solve the problem that the ferrite core is liable to be broken and to make the transformer thinner. Another object of the present invention is to provide a thin transformer that employs a core having a high saturation magnetic flux density and is hardly magnetically saturated, and does not take up a large mounting substrate area even when the thickness is reduced. SOLUTION: A thin transformer is formed by arranging a plurality of tubular cores, forming a loop with a conductive wire continuously penetrating the plurality of tubular cores, and forming a primary coil or a secondary coil.
In addition, a single transformer penetrating a plurality of cylindrical cores is connected in parallel to form a thin transformer as a primary coil. Further, a thin transformer is formed by using a core formed by winding a magnetic thin plate of an amorphous ultrafine crystal alloy on the core of the transformer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer used for an electronic device or a power converter such as an inverter.

[0002]

2. Description of the Related Art As a magnetic material of a transformer used in a conventional electronic device or a power converter such as an inverter, a laminated silicon steel plate or a Mn or Zn ferrite core is used.
Twisted wires are used for those with small current capacity for coil conductors wound around them, and for those with large current capacity,
In order to reduce the eddy current loss due to the AC magnetic field and to improve the workability of the wound wire, a double wire in which insulated single wires are arranged in parallel and a thick round wire are used. In the case of a laminated silicon steel sheet, an EI core was used, and in the case of a ferrite core, a block-shaped closed magnetic circuit core such as a ring core was used, and the primary coil and the secondary coil were wound in multiple layers.

In order to transmit the power required for the transformer without magnetic saturation, a predetermined magnetic path cross-sectional area is required depending on the material of the core. There is. For this reason, when trying to form a thin core, in the case of a laminated silicon steel sheet or the like, a punched sheet having an irregular shape is formed, and the material yield is reduced, which is uneconomical.

[0004] In the case of a ferrite core, the core becomes thin and large, so that problems such as warpage due to baking distortion during firing of the core and cracking easily occur. In addition, the conventional silicon steel sheet has a frequency characteristic that does not extend to a high-frequency region, and the ferrite material is not so large in saturation magnetic flux density, and is easily magnetically saturated. However, when the thickness is reduced as described above, a large-sized transformer requires a considerable mounting substrate area. Also, a transformer having a large voltage step-up ratio, that is, a transformer having a large winding ratio, needs to increase the number of windings by making the secondary winding multilayer.

[0005]

The conventional magnetic transformer eliminates the limitation on the height of the closed magnetic circuit core due to its block shape, prevents the reduction of the material yield in the case of a laminated silicon steel sheet, etc., and further reduces the case of a ferrite core. An object of the present invention is to solve the problem that the transformer is easily cracked and to make the transformer thinner. In addition, by connecting a single conducting wire penetrating each core in parallel to form a primary coil, even if the number of secondary windings is small, the winding ratio is equivalently large, that is, the voltage step-up ratio. Another object of the present invention is to provide a thin transformer that uses a core having a large saturation magnetic flux density and is hardly magnetically saturated, and does not require a large mounting substrate area even if the thickness is reduced.

[0006]

According to a first aspect of the present invention, a plurality of cylindrical cores are arranged in a transformer in which a primary coil and at least one or more secondary coils are wound around a magnetic core. Is a thin transformer in which primary and secondary coils are formed by forming a loop by continuously penetrating the plurality of tubular cores and forming a single or plural winding numbers.

[0007] Instead of a block-shaped core like a conventional transformer, the function as the core of the transformer is distributed to a plurality of cylindrical cores, and a winding wire continuously penetrating the plurality of cylindrical cores. To form a loop and function as one transformer as a whole. In the case of ferrite, the cylindrical core can be easily made into either a square tube or a cylinder, but when using a magnetic ribbon, it can be punched and laminated into a hollow square plate or disk, but it can be made into a cylindrical shape. Winding is easier to build.
Further, the corners of the core wound in a cylindrical shape need to be deburred and rounded, or thinly coated with an epoxy resin or the like so that the insulating film of the wound wire is not damaged.

[0008] A plurality of turns can be wound by repeatedly forming a loop to form one turn with a conductive wire continuously penetrating a plurality of cylindrical cores, and furthermore, any of the plurality of cylindrical cores can be wound. , The winding can be completed at the end, and a fractional number of windings can be selected, and the secondary voltage can be set finer and more accurately.

Accordingly, the thickness (height) of the transformer is
The transformer having a desired thickness can be realized by increasing the number of the tubular cores according to the power and increasing the mounting area of the substrate, which is determined by the outer shapes of the plurality of tubular cores. Also, since the shape of the area to be mounted on the board can be freely changed by changing the arrangement method of the multiple cylindrical cores, the shape can be designed according to the empty space of the set board on which the transformer is mounted. The size of the set can be reduced.

According to a second aspect of the present invention, a plurality of cylindrical cores are arranged in a transformer structure in which a primary coil and at least one or more secondary coils are wound around a magnetic core, and a conductor is formed of the plurality of cylindrical cores. A loop is formed by continuously penetrating the cylindrical core,
A secondary coil is formed by forming one or a plurality of winding numbers, and further, for each of the plurality of tubular cores, a lead wire that is respectively connected therethrough is connected in parallel to form a primary coil. It is a characteristic thin transformer.

In the secondary coil, the number of windings is increased by repeating a number of times that a conductive wire continuously penetrates the plurality of cylindrical cores and forms a loop, thereby increasing the number of windings. Can be increased, but
By connecting the conducting wires passing through each core of the plurality of cylindrical cores in parallel to form a primary coil, the primary and secondary winding ratios having low input impedance were multiplied by the number of cores. Thus, a transformer having a high step-up ratio can be formed, and the coupling coefficient does not decrease.

According to a third aspect of the present invention, a plurality of tubular cores are arranged, at least a secondary coil continuously penetrates the plurality of tubular cores, and a loop is formed to form one or more coils. A thin transformer characterized by using a core formed by winding a magnetic thin plate of an amorphous ultrafine crystal alloy on a plurality of cores of the transformer.

As shown in FIG. 6, when a core formed by winding a magnetic thin plate of an amorphous ultrafine crystalline alloy is used, the saturation magnetic flux density is higher than that of a conventional manganese zinc (Mn, Zn) ferrite core. And a high magnetic permeability, it is possible to form a small core having a small magnetic path cross-sectional area. The core formed by winding a magnetic thin plate of an amorphous ultrafine crystalline alloy has a higher permeability and a higher frequency characteristic of Q characteristics than a silicon steel plate of the same thickness. Suitable for.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In order to constitute one transformer of a predetermined power, a plurality of transformers share power, and the primary coil and the secondary coil of each transformer are connected in parallel or in series, respectively. Thus, one transformer is constituted as a whole. This makes it possible to reduce the thickness. In particular, by connecting the primary side of each transformer in parallel and the secondary side in series to form one transformer, the input impedance is low and the voltage step-up ratio is large. Transformers can be configured.

[0015]

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of the present invention based on an equivalent circuit of the step-up transformer having a step-up ratio of 1: 5 shown in FIG. A 20 μm thick, 33.5 mm wide amorphous nanomicron crystal alloy ribbon (Nanopalm, manufactured by Alps Electric Co., Ltd.) is wound to form a cylindrical core having an outer diameter of 8.9 mm, an inner diameter of 4 mm, and a width of 33.5 mm. Then, the tube was covered with a heat-shrinkable tube and shrunk by heating to form a cylindrical core 3 having an external insulation treatment.

Next, a five-turn loop was formed by continuously penetrating the above-mentioned five cylindrical cores five times with a 0.7 mmφ insulated stranded wire 2 for a secondary coil. At this time, using a jig (not shown) in which five cylindrical cores are arranged in a straight line and the circumference of the loop is a predetermined length, the conductor is penetrated through the five cylindrical cores five times. Then, a 5-turn loop was formed. Next, a loop of 5 turns is formed.
The three stranded insulated wires were folded in a zigzag manner to arrange five cylindrical cores in parallel.

Next, a 1 mmφ insulating coated copper wire having a length of about 70 mm for the primary coil is passed through the five cylindrical cores once as in the case of the secondary coil, and the primary coil is formed on the back surface.
From the upper surface of the substrate on which the wiring pattern for connecting the terminals of the secondary coil is formed, insert both ends of the primary coil and the secondary coil into predetermined terminal holes, respectively, and solder-dip the back surface of the substrate to form a through-hole on the back surface of the substrate. 4 was soldered to the lands, and both ends were cut to a predetermined length to complete the thin transformer shown in FIG.

[0018]

Embodiment 2 Based on the equivalent circuit of a step-up transformer having a step-up ratio of 1:25 shown in FIG. 3, in the same manner as in Example 1, five identical cores are used, and an insulating coating of 0.7 mmφ is used for a secondary coil. The stranded wire 2 was made to pass through the five cylindrical cores continuously and integrally five times to form a five-turn loop. At this time, a jig (not shown) in which five cylindrical cores were arranged in a straight line and the loop had a predetermined length was used. Then, the five-turn loop penetrating the five cylindrical cores was removed from the jig, and the five insulated stranded wires forming the loop were folded in a zigzag manner so that the five cylindrical cores were arranged in parallel.

Next, five 1 mmφ insulated copper wires each having a length of about 70 mm for the primary coil were passed through the five cylindrical cores one by one, and both ends were connected in parallel. From the upper surface of the substrate on which the wiring pattern for connecting the terminals of the secondary coil and the secondary coil is formed, insert both ends of the primary coil and the secondary coil into predetermined terminal holes, and solder-dip the back surface of the substrate. The thin transformer shown in FIG. 1 was completed by soldering to the land of the through hole on the back surface of the substrate and cutting both ends to a predetermined length.

[0020]

According to the present invention, since a conventional transformer core is a block-shaped closed magnetic circuit core, the height of the core is not limited to a certain value or more, so that a plurality of cylindrical cores are arranged in a unitary winding. By configuring the wires, a thin transformer can be realized. Also, by connecting the conductors passing through each core in parallel,
By forming the next coil, a voltage boosting ratio is obtained by multiplying the winding ratio by the number of cores. Further, it is possible to provide a thin transformer in which a core having a high saturation magnetic flux density and a material which is hardly magnetically saturated is adopted, and the mounting substrate area is kept small even if the thickness is reduced.

[0021]

[Brief description of the drawings]

FIG. 1 shows a transformer assembly diagram according to a second embodiment of the present invention.

FIG. 2 is a circuit diagram of a transformer having a winding ratio of 1: 5 according to the first embodiment.

FIG. 3 is a circuit diagram of a transformer having a winding ratio of 1:25 according to the second embodiment.

FIG. 4 is an assembly diagram of the transformer according to the first embodiment.

FIG. 5 shows the magnetic saturation characteristics of the core depending on the material.

[Explanation of symbols]

 1 ... primary winding 2 ... secondary winding 3 ... cylindrical core 4 ... printed circuit board

Claims (3)

[Claims] A transformer comprising a magnetic material core wound with a primary coil and one or more secondary coils,
A plurality of cylindrical cores constituting the transformer, forming a winding wire through which a conductor penetrates to create one or more loops,
A thin transformer characterized by comprising a coil. 2. A transformer in which a primary coil and one or more secondary coils are wound around a magnetic core,
The secondary coil is a conductor that continuously penetrates the plurality of cylindrical cores to form a loop, and a single coil or a plurality of coils are formed. The primary coil penetrates each of the plurality of cylindrical cores. A thin transformer, wherein one conductor is connected and formed in parallel. 3. The thin transformer according to claim 1, wherein a core formed by winding a magnetic thin plate of an amorphous ultrafine crystal alloy is used for a plurality of cores of the transformer. Thin transformer.