JPS63228605A - Inductance element - Google Patents

Abstract

PURPOSE:To prevent saturation of magnetic cores even if a current is high to some extent or more and to make the entire element compact, by arranging a soft magnetic body between a magnetic core and a magnetic core constituting a magnetic circuit, and constituting the element so that the number of magnetic fluxes passing through the soft magnetic bodies is changed based on the magnitude of a winding current. CONSTITUTION:A gap material 4 and a soft magnetic material, whose permeability is higher than those of an I-type core 2 and an E-type core 3, are inserted in the connecting parts of the I-type core 2 and the E-type core 3. A winding 5 is wound around the central leg of the E-type core 3. When a current I is made to flow, the number of magnetic fluxes phi2 passing the soft magnetic material 1 is few when the winding current I is small. Therefore the inductance value L of a part as an inductance element indicates a large value. When the winding current I becomes large, the number of the magnetic fluxes passing the soft magnetic material 1 is increased to phi1. When the value of phi1 exceeds the saturated magnetic flux density of the soft magnetic material 1, the soft magnetic material 1 becomes equivalent to non-existence of the material 1 itself. The insuctance value L as the inductance element indicates a small value. Since the inductance value can be changed by the winding current of the inductance element, the element can be made compact.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in inductance elements used in switching power supplies and the like, and particularly relates to an inductance element suitable for downsizing power supplies.

[Conventional technology]

Conventionally, inductance elements used in switching power supplies, etc. are designed so that the saturation current is larger than the maximum value of the normal WI current, as seen in, for example, Japanese Patent Publication No. 19097/1983. This is because the dimensions are approximately proportional to LI'' (L is inductance, I is saturation current).

The disadvantage was that it was inevitably large.

[Problem that the invention seeks to solve]

In this way, when configuring a magnetic circuit using a standard magnetic core as the magnetic core, the dimensions of the inductance element are LI'' (L
is approximately proportional to the inductance and (■ is the saturation current), so it has the disadvantage that the overall size of the device inevitably increases.

The present invention was made to eliminate the above-mentioned drawbacks, and aims to reduce the size of the entire device by preventing the magnetic core from being saturated even when the current is large beyond a certain level.

[Means for solving problems]

The above objective is achieved by arranging a soft magnetic material between the magnetic cores constituting the magnetic circuit, and configuring the structure so that the number of magnetic flux passing through the soft magnetic material changes depending on the magnitude of the winding current. . With this configuration, when the magnetic flux exceeds the saturation magnetic flux density of the soft magnetic material, the inductance value of the inductance element can be reduced, thus achieving miniaturization of the inductance element.

[Effect]

As mentioned above, by arranging a soft magnetic material between the magnetic cores constituting a magnetic circuit, the number of magnetic fluxes passing through the soft magnetic material due to the current flowing through the inductance element increases to the saturation magnetic flux of the soft magnetic material. By configuring the inductance to change depending on whether or not the density is exceeded, it is possible to reduce the size of the inductance element.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIG. In the figure, 1 is a soft magnetic material, 2 is a type 1 core, and 3 is a type 1 core.
is an E-type core, and 4 is a gap member (non-magnetic material).

Next, the operation of this embodiment will be explained. As shown in FIG. 1, a gap material (non-magnetic material) 4 is provided at the opposing portion of the type 1 core 2 and the type E core 3, and a soft magnetic material with higher magnetic permeability than the type 1 core 2 and the type E core 3. Insert the material. A winding 5 is wound around the center leg of the E-type core 4, and an electric current is passed through it. As shown in FIG. 2, while the winding current (DC current) is small, the number of magnetic fluxes φ2 passing through the soft magnetic material 1 is small, so the inductance value as an inductance element shows a large value. As the winding current increases, the number of magnetic fluxes passing through the soft magnetic material 1 increases to φ1, and when the value of φl exceeds the saturation magnetic flux density of the soft magnetic material 1, the soft magnetic material 1 This is equivalent to not existing, and the inductance value as an inductance element shows a small value. On the other hand, FIG. 3 shows the relationship between the inductance value and current of a conventional inductance element.

Another embodiment of the present invention is shown in FIG. 4, in which E-shaped cores are placed in contact with each other, a gap material 4 and a soft magnetic material 1 are interposed in the opposing parts, and windings 5 and 5 are provided on both end legs. It is a transformer with a Even in this case, the above-mentioned matters hold true in exactly the same way.

〔Effect of the invention〕

According to the present invention, in the switching regulator,
Since the inductance value can be changed by the winding current of the inductance element, it is possible to provide an inductance element (choke coil or transformer) smaller than conventional ones.

[Brief explanation of drawings]

Fig. 1 is a diagram showing one embodiment of the present invention, Fig. 2 is a curve diagram showing the relationship between the inductance value and the winding current in the above embodiment, and Fig. 3 is the relation between the inductance value and the winding current according to the conventional example. FIG. 4 is a curve diagram showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Soft magnetic material, 2... 1 type core, 3... E type core, 4... Gap material (non-magnetic material), 5... Winding wire. 1st eye 2nd country? L side road L(A)

Claims (1)

[Claims] 1. A magnetic circuit is constructed by placing two magnetic cores in contact with each other, and interposing a gap material made of a non-magnetic material and a soft magnetic material in layers in the opposing portion of the two. An inductance element characterized by: 2. The inductance element according to claim 1, wherein the soft magnetic material is made of a magnetic material having higher magnetic permeability than the magnetic material that is the magnetic core.