JPS63261907A - Noise filter - Google Patents

Abstract

PURPOSE:To contrive the miniaturization of a constitution by assembling a magnetic substance between coil inductances whose magnetic flux is cancelled together so as to reduce the magnetic coupling. CONSTITUTION:Inductance elements forming a noise filter together with a capacitor element are formed by windings 10a, 10b to be connected so as to cancel the magnetic flux together onto a magnetic core 13. Then a leakage magnetic flux magnetic body 14 decreasing the magnetic coupling between the windings 10a and 10b is assembled in the inductance elements and the magnetic coupling coefficient is decreased even with the small sized inductance element to act like noise effectively. The constitution of the noise eliminating filter is simplified and miniaturized by using one magnetic body so as to adjust the inductance.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention prevents malfunctions caused by noise in DC stabilized power supplies incorporating ICs and transistors used in all fields, both consumer and industrial. This relates to noise filters used for

Prior Art Figure 4 shows the main circuit when a noise filter is actually used, in which 1 is an input connector, 2 &.

2b is an inductance element; 3a, sb, 3c are capacitor elements; 4 is an inductance element 2a, 2
b, a noise filter constituted by capacitor elements 3N, 3b, and sc, and 6 indicates a load. The conventional structure of the inductance elements 2a and 2b in this circuit diagram is shown in FIG. In FIG. 4, the two inductance elements 21L and 2b are constructed by winding an enamelled copper wire 7 around a coil bobbin 6 and inserting a magnetic core 8 therethrough, as shown in FIG. 6. These two inductance elements 2a
.

The wires 2b are connected so that the magnetic fluxes caused by the load current during use cancel each other out.

Problems to be Solved by the Invention In the wiring diagram in the usage state shown in Figure 4, the inductance element 21L when noise comes in from the AC power supply side,
Consider the function of 2b.

There are two types of noise; one is line-to-line noise (
The other one is line-to-ground noise (symmetric disturbance wave).
(asymmetric disturbance wave). Therefore, inductance element 2
The functions of 1L and 2b need to be considered with respect to these two noise looses. Regarding the line-to-line noise component, since the inductance elements 21L and 2b are connected so that their magnetic flux is canceled out, the inductance (LN) that functions in the line-to-line loop is the inductance of the inductance elements 21L and 2b as L11' L22
If mutual inductance is M and coupling coefficient is K, then L(,1)=L1. +L2□-2M:=L,, +L2□-2 has Echo Seiden... (1) L11
= L2□, so L(RI2 Ll, -2KL1. = 2L, 1(1
-K)...(2). Therefore two inductance elements 2&.

As the coupling of 2b becomes denser, the coupling coefficient approaches 1, so L
(N)U becomes very small. As a result, they no longer function as inductance elements 2&, 2b. This problem becomes more noticeable as the inductance elements 21L and 2b become smaller (because the distance between the windings becomes shorter).

The present invention provides a noise filter that effectively functions against line-to-line noise when the inductance element becomes smaller and the coupling coefficient between windings becomes larger.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention comprises an inductance element consisting of at least two windings and a plurality of capacitor elements connected so that magnetic flux cancels out, and a plurality of capacitor elements. This structure incorporates a magnetic material that reduces magnetic coupling between inductances.

Effects With the above configuration, even if the device is miniaturized, it is effective against line-to-line noise, and the characteristics of the inductance element can also be controlled using a magnetic material.

Embodiment 1 An embodiment of the present invention will be described below with reference to the accompanying drawings FIGS. 1 to 3.

101L, 10b has 11 coil bobbins each.

This winding consists of winding the enamelled copper wire 12 around 11b, and this winding @1o! A magnetic core 13 made of EE type ferrite is incorporated in L and 10b, and windings 10&, 1
A ring-shaped magnetic body 14 is incorporated between the windings 10a and 10b to reduce the magnetic coupling between the windings 10a and 10b, thereby forming two inductance elements.

These two inductance elements are connected to several capacitor elements using lines as shown in Fig. 4 to constitute a noise filter, and the winding 101L of the inductance element is
, 10b are connected so that their magnetic fluxes cancel each other out.

As described above, in the present invention, a disk-shaped magnetic body 1o as shown in FIG. 3 is mounted between the windings 6a and 6b. Therefore, a portion of the magnetic fluxes generated in the two windings 61.6b, φ and φ' in FIG. 2, become magnetic fluxes that do not interlink with each other, that is, leakage fluxes. The coupling coefficient (
Since K) can be changed, the required inductance L (N) according to the above equation (threshold) can be obtained. By changing υ can be obtained arbitrarily.

Effects of the Invention As described above, the noise filter of the present invention is configured so that it can function effectively against line-to-line noise even though it is very small. The shape of the magnetic material can be changed, and an inductance element with the required characteristics can be formed using a single disk-shaped magnetic material, so it has the advantages of being small and inexpensive, and has industrial value. It is a dog.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the noise filter of the present invention, Fig. 2 is a sectional view thereof, Fig. 3 is a perspective view of a magnetic material for leakage magnetic flux used in the noise filter, and Fig. 4. 5 is a wiring diagram showing how the noise filter is used, and FIG. 5 is a perspective view of a conventional noise filter. 102L, 10b---winding, 112L, 1
1b・river-coil bobbin, 12...enamel copper fm, 13...magnetic core, 14...magnetic material. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure/Iku Koi) Rehovin Figure 2, 4 /θ Ku Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A noise filter comprising an inductance element consisting of at least two windings connected so that magnetic flux cancels out, and a plurality of capacitor elements, and incorporating a magnetic body between the inductance elements to reduce magnetic coupling between the windings.