JPH06224045A - Lc composite element - Google Patents

Abstract

PURPOSE:To provide an LC composite element, which is constituted as a complete balanced circuit and is optimum as a common mode noise filter. CONSTITUTION:An LC composite element is constituted into a structure, wherein electrode foils and dielectric sheets 4a are wound on a magnetic core (a ferrite core) 6 in a state that the foils and the sheets 4a are alternately superposed and an LC balanced circuit consisting of capacitors and a coil is formed. The electrode foils 2a for coil formation use are respectively held between the electrode foils 3 for X capacitor formation use and the electrode foils 1a and 1b for Y capacitor formation use to constitute respectively the electrode fills in three layers, the foils 3 are provided in the total width of the core and extending over the total length in the winding direction, the foils 1a and 1b are respectively provided at the starting end and the terminal in the winding direction in the total width in the width direction of the core and the foils 2a are provided side by side extending over the total length in the winding direction via a slit (a bobbin) 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LC used as a noise filter, which is constructed by alternately laminating electrode foils and dielectric sheets on a magnetic core to form an LC balanced circuit.
Regarding composite elements.

[0002]

2. Description of the Related Art As a common mode noise filter,
There is a toroidal core that uses a toroidal coil in which a number of windings corresponding to the number of power supply phases of the same number of turns is used, and noise is eliminated by utilizing the mutual canceling action of the magnetic field by the reciprocating load current.

This is because it is difficult to form a balanced circuit by winding a plurality of identical windings with a coupling coefficient close to 1 and a toroidal core, and another element for constructing a filter circuit. However, there is a problem that the capacitor must be provided separately.

Therefore, for example, an LC filter for removing common mode noise mixed in the power supply line is used.
Composite elements are used. This LC composite element is generally
Electrode foils and dielectric sheets are alternately stacked on the magnetic core and wound in the same manner as a wound-type capacitor to form a balanced circuit with an inductance L and a capacitance C. This LC composite element includes both elements of the inductance L and the capacitance C in one element, and has the advantage that it can be easily manufactured in the same way as a capacitor and is compact.

[0005]

In the LC composite device having such advantages, it is difficult to obtain a perfect balanced circuit due to its structural reason. That is, in the LC composite element, since the electrode foil and the dielectric sheet are wound around one core, a spiral structure is formed and perfect symmetry cannot be obtained. As a result, it is difficult to achieve magnetic balance due to the reciprocating current, and it is difficult to configure a common mode noise filter that can adapt to a large current.

The present invention has been made in consideration of the above points, and an object of the present invention is to provide an LC composite element which is configured as a perfectly balanced circuit and is optimal as a common mode noise filter.

[0007]

To achieve the above object, the present invention provides an LC balance consisting of a capacitor and a coil which are wound on a magnetic core in a state where electrode foils and dielectric sheets are alternately stacked. In an LC composite element forming a circuit, X
The coil forming electrode foil is sandwiched between the capacitor forming electrode foil (X-con forming electrode foil) and the Y capacitor forming electrode foil (Y-con forming electrode foil) to form a three-layer electrode foil, The con-forming electrode foil is provided over the entire width and the entire length in the winding direction, and the Y-con forming electrode foil is provided in the width direction at the entire width and at the beginning and end of the winding direction. A plurality of slits are arranged side by side over the entire length in the winding direction through the slits.

[0008]

[Operation] A plurality of coil forming electrode foils are arranged side by side over the entire length in the winding direction through slits and are symmetrical. Since the X-con forming electrode foil and the Y-con forming electrode foil are sandwiched between the inside and outside in the thickness direction of the coil forming electrode foil, these electrode foils are wound together with the dielectric sheet to form an LC composite element. However, the symmetry of each electrode foil, the dielectric sheet, and the LC composite element as a whole is maintained. If the symmetry of the LC composite element as a whole is maintained, electrical and magnetic equilibrium is maintained inside the element during energization, and even if a large current is passed, the magnetic core does not cause magnetic saturation, and as an inductance, Since the function is not impaired, the filter action is performed.

[0009]

1 is an exploded perspective view of an embodiment of the present invention. In the figure, 1a and 1b are electrode foils for forming Y-con,
Reference numerals 2a and 2b are electrode foils for coil formation, 3 is an electrode foil for forming X-con, and 4a, 4b and 4c are dielectric sheets. The Y-con forming electrode foils 1a and 1b and the coil-forming electrode foils 2a and 2b are stacked with the dielectric sheet 4a interposed therebetween, and the coil-forming electrode foils 2a and 2b and the X-con forming electrode foils are stacked. 3, the dielectric sheet 4b is sandwiched between them, and the X-con forming electrode foil 3 is overlaid with the dielectric sheet 4c. As shown in FIG. 3, a Y-con forming electrode foil 1
a and 1b are full width in the width direction and are provided at the beginning and end of the winding direction, and a plurality of coil forming electrode foils 2a and 2b are arranged side by side through the slit 5 along the entire length in the winding direction to form an X-conformation. The electrode foil 3 for use is provided over the entire width and the entire length in the winding direction. Then, as shown in FIG. 1, the dielectric sheet 4
It is wound around the bobbin 6 with c inside. A ferrite core 7 is inserted in the bobbin 6 as a magnetic core.

The Y-con forming electrode foils 1a and 1b are provided with grounding terminals 11 and 21, and the coil forming electrode foils 2a and 2b are provided with energizing terminals 12 and 13 at the inner ends thereof. Energization terminals 22 and 23 are connected to the outer ends of 2a and 2b, respectively. As a result, the energizing terminal 1
2, 13 and energizing terminals 22 and 23, and a grounding terminal 1
A 6-terminal circuit including 1 and 21 is configured.

FIG. 2 shows an equivalent circuit of the embodiment shown in FIG. That is, the coil L ₁ formed by the coil forming electrode foil 2 a is inserted in series between the energizing terminals 12 and 22, and the coil forming electrode foil 2 b is formed between the energizing terminals 13 and 23. The coil L ₂ is inserted in series. Then, the Y-con forming electrode foils 1a and 1b are connected to the grounding terminals 11 and 21, respectively, and the coils L ₁ and
A distributed capacitance C _Y is formed with L ₂ . Further, the coil forming electrode foils 2a and 2b and the X-conn forming electrode foil 3 disposed inside thereof form a distributed capacitance C _X.

As a result, when the terminals 11 to 13 in the figure are the input side and the terminals 21 to 23 are the output side, a filter circuit as a perfectly balanced circuit is formed between the input and output terminals.

FIG. 4 shows another embodiment of the present invention corresponding to FIG. In this embodiment, the coil forming electrode foil is divided into three coil forming electrode foils 2a, 2b and 2c via two slits 5 and 5 to form three coils. As a result, a balanced circuit having three coils and a current-carrying line is formed, so that it can be used as a common mode noise filter applicable to a three-phase power supply circuit.

In the above embodiment, the core is of an open magnetic type. However, for example, at least two U-shaped ferrite cores are formed so as to symmetrically magnetically couple the both ends of the ferrite core 7. It is also possible to form a closed magnetic type by combining

[0015]

As described above, according to the present invention, the electrode foil for forming a coil is sandwiched between the electrode foil for forming a X capacitor and the electrode foil for forming a Y capacitor, and the electrode foil for forming a coil is sandwiched between the electrode foil for forming a coil and the electrode foil for forming a Y capacitor. age,
The X-con forming electrode foil is provided over the entire width and the entire length in the winding direction, the Y-con forming electrode foil is provided in the entire width in the width direction at the beginning and end of the winding direction, and the coil-forming electrode foil is wound through the slit. Since multiple units are arranged side by side along the entire length in the direction, electrical and magnetic symmetry can be obtained, in particular magnetic symmetry centered on the coil is secured, and the magnetic core causes magnetic saturation due to magnetic imbalance. A good filter action can be performed without

[Brief description of drawings]

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

FIG. 2 is an equivalent circuit diagram of the embodiment shown in FIG.

FIG. 3 is a development explanatory diagram of the embodiment of FIG.

FIG. 4 is a development explanatory diagram of another embodiment of the present invention.

[Explanation of symbols]

1a, 1b ... Y-con forming electrode foil, 2a, 2b, 2c ...
Coil forming electrode foil, 3 ... X-con forming electrode foil, 4a,
4b, 4c ... Dielectric sheet, 5 ... Slit, 6 ... Bobbin, 7 ... Ferrite core, 11, 21 ... Grounding terminal, 1
2, 13, 22, 23 ... energizing terminals, C _X , C _Y ... Distributed capacitance, L ₁ , L ₂ ... Coil

Claims (3)

[Claims] 1. An electrode for forming an X capacitor in an LC composite element, wherein an electrode foil and a dielectric sheet are wound on a magnetic core in a state of being alternately stacked to form an LC balanced circuit including a capacitor and a coil. The coil forming electrode foil is sandwiched between the foil and the Y capacitor forming electrode foil to form a three-layer electrode foil, and the X capacitor forming electrode foil is provided over the entire width and the entire length in the winding direction. The capacitor forming electrode foil has a full width in the width direction and is provided at the starting end and the terminating end in the winding direction, and the coil forming electrode foils are arranged in parallel over the entire length in the winding direction via slits. LC composite element. 2. The LC composite element according to claim 1, wherein
The magnetic core is an open magnetic type LC composite element. 3. The LC composite element according to claim 1, wherein
The LC composite element in which the magnetic core is a closed magnetic type.