JPH0457307A - Electromagnetic device - Google Patents

Abstract

PURPOSE:To restrain eddy current loss and reduce temperature rise, by a method wherein the region where the eddy current flows is limited when magnetic flux interlinks a conductor foil, by forming the conductor foil in a slender type, and arranging a lot of the foils on an insulating sheets so as to keep insulation intervals. CONSTITUTION:A pair of insulating sheets 2 wherein a lot of slender conductor foils 1 are arranged so as to keep insulation intervals and electrodes 3 are formed on both ends of the conductor foils 1 are prepared. These insulating sheets 2 are stacked and wound, in the manner in which the longitudinal direction of the conductor foil 1 is made the winding direction. Hence the conductor foils 1 arranged on each insulating sheet 2 function as capacitors. When currents are made to flow in the same direction through the conductor foils 1 on each insulating sheet 2, the function as choke coils is obtained. The conductor foils 1 have a slender type and arranged on the insulating sheet 2 so as to keep insulation intervals in the above manner, so that the region where a current flows is limited when magnetic flux interlinks the conductor foils 1. Thereby eddy current loss is restrained, and temperature rise can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to electromagnetic devices such as high frequency LC composite elements applied to switching power supplies, inverter circuits, and the like.

[Conventional technology]

Conventional examples are shown in FIGS. 6 to 11. That is, this electromagnetic device has a pair of insulating sheets 32.33 provided with a conductive foil 30.31 and electrodes 34 provided at both ends of the conductive foil 30.31, and these insulating sheets 32.33 are connected to a seventh They are stacked and wound around a magnetic core 36 as shown in the figure. 3
5 is a gap between the magnetic cores 36.

The conductor foils 30 and 31 of two insulating sheets 32 and 33 wound around the magnetic core 36 constitute a capacitor. Moreover, by connecting each electrode 34 of the conductor foil 30.31 as shown in FIG. 8 or 9 so that the direction of the current flowing through the conductor foil 30.31 is the same, each conductor foil 30.31
functions as a choke coil. Note that the arrows in FIG. 6 indicate the direction of current, FIG. 10 is the equivalent circuit of FIG. 8, and FIG. 11 is the equivalent circuit of FIG. 9.

I represents a current, P, , P2 represents an electromagnetic device.

As a result, this single electromagnetic device has the characteristics of both a choke coil and a capacitor.

[Problem to be solved by the invention]

However, when this electromagnetic device is operated at a high frequency of several tens of kHz to several hundred kHz, such as in a switching power supply or an inverter circuit, an eddy current r' is generated due to the magnetic flux Φ interlinking with the conductor foil 3031. There was a drawback that the temperature rise of the conductor foils 30, 31 increased due to the increase in loss.

Therefore, it is an object of the invention to provide an electromagnetic device capable of reducing the eddy current product.

[Means to solve the problem]

The electromagnetic device of the present invention has a pair of insulating sheets in which a large number of elongated conductive foils are arranged side by side at insulation intervals, and electrodes are provided at both ends of the conductive foils, and these insulating sheets are stacked. The conductor foil is wound so that the longitudinal direction thereof is the winding direction.

[Effect]

According to the configuration of the present invention, the conductor foil provided on each insulating sheet functions as a capacitor, and the conductor foil of each insulating sheet functions as a choke coil by passing current in the same direction. have In this case, the conductor foil is long and thin and is placed in parallel with the insulating sheet with insulation intervals, so even if the magnetic flux interlinks with the conductor foil, the area where the eddy current flows is restricted, so the eddy current can be increased. can be suppressed, and temperature rise can be reduced. Furthermore, by selecting the number of elongated conductor foils to be applied to a circuit, it is possible to change the capacitance as a capacitor, and it is also possible to apply the electromagnetic device to a plurality of circuits at the same time.

〔Example〕

An embodiment of the present invention will be explained based on FIGS. 1 to 5. That is, this electromagnetic device has a conductor foil 1 and an insulating sheet 2.

A large number of conductor foils 1 are elongated and arranged side by side on an insulating sheet 2 at insulating intervals, and furthermore, electrodes 3.4 are provided at both ends of the conductor foil 1 to span the entire conductor foil 1. In the embodiment, a single conductor foil is provided on a flexible insulator 2a, and a long and narrow conductor foil 1 is formed at one time by etching or the like, and the insulator 2a is provided on an insulating sheet 2.

There are a pair of insulating sheets 2, which are stacked as shown in FIG. 2 and wound around the magnetic core 5 such that the longitudinal direction of the conductor foil 1 is the winding direction. 6 is a gap between the magnetic cores 5.

FIG. 2 shows an example of a circuit in which the conductor foils 1 are connected so that current flows in the same direction, and corresponds to FIG. 8 and FIG. 1O. ■ is the power supply.

This electromagnetic device consists of a conductor foil 1 provided on each insulating sheet 2.
It functions as a capacitor, and also functions as a choke coil by passing current through the conductor foil 1 of each insulating sheet 2 in the same direction.

In this case, since the conductor foil 1 is elongated and arranged in parallel with the insulating sheet 2 with an insulating interval, the area where the magnetic flux interlinks with the conductor foil 1 and the eddy current flows is restricted. Eddy current product can be suppressed and temperature rise can be reduced.

Further, by selecting the number of elongated conductor foils 1 to be applied to the circuit, the capacitance as a capacitor can be changed. For example, if the electrodes 3 and 4 are connected to half the total number of conductor foils 1 as shown in FIG. 4, the capacitance of the capacitor is reduced to 2.

Further, as shown in FIG. 5, by providing a plurality of electrodes 3.3' and 4.4' connected to a part of the conductor foil 1 and connecting each to a different load circuit, a plurality of circuits can be connected. It also becomes possible to apply electromagnetic devices at the same time.

In addition, in comparison with the conventional example, the cross-sectional area of the conductor foil 1 is reduced, which may increase the electrical resistance and increase the electrical loss. However, since the frequency used is high, the conventional high-frequency choke Just as the coils and transformers use Lindt wire instead of solid wire, the presence of the skin effect also reduces electrical loss.

〔Effect of the invention〕

According to the electromagnetic device of the present invention, a large number of conductor foils are made into elongated shapes and arranged side by side on an insulating sheet at insulation intervals, so that even when magnetic flux interlinks with the conductor foils, the area where eddy current flows is restricted. Current product can be suppressed and temperature rise can be reduced. Furthermore, by selecting the number of elongated conductive foils to be applied to a circuit, the capacitance as a capacitor can be changed, and the tMi device can also be applied to a plurality of circuits at the same time.

[Brief explanation of the drawing]

Part 1 is a perspective view showing the insulating sheet in the middle of winding according to an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the connection state as a choke coil, and Fig. 3 is a part showing the conductor foil and the insulating sheet. A perspective view, FIG. 4 is an explanatory diagram illustrating the connection of electrodes when a small capacitance is required, FIG. 5 is an explanatory diagram illustrating a connection example when applied to multiple circuits, and FIG. FIG. 7 is a side view of the insulating sheet and conductor foil, FIGS. 8 and 9 are different connection diagrams when used as a choke coil, and FIG. 10 is a perspective view showing the insulating sheet being wound in the middle. FIG. 8 is an equivalent circuit diagram, and FIG. 11 is an equivalent circuit diagram of FIG. 9. 1... Conductor foil, 2... Insulating sheet, 3.4... Electrode diagram Figure 4 Shinrei

Claims (1)

[Claims] It has a pair of insulating sheets in which a large number of elongated conductive foils are arranged side by side at insulation intervals, and electrodes are provided at both ends of the conductive foils, and when these insulating sheets are stacked, the longitudinal direction of the conductive foils is An electromagnetic device that is wound in such a way that the winding direction is the same.