JPH0494205A - Noise filter - Google Patents

Abstract

PURPOSE:To reduce the manufacture man-hour and the manufacture cost and to improve the characteristic by employing a coated conductor for plural conductors, winding the coated conductors onto an annular magnetic core while they are twisted. CONSTITUTION:A coated conductor insulated with an insulation material having a high dielectric strength between conductors such as a polyester coated copper wire is employed for conductors 11-13 connected among terminals U, V, W, R, S, T of a noise filter 10. Then the coated conductors 11-13 are twisted in advance as a twisted wire 14 and a coil is formed by winding the twist wire 14 on an annular magnetic core 15. Thus, the twist wire is wound uniformly on the entire circumference of the annular magnetic core 15 to allow almost no leakage magnetic flux to exist, an excellent characteristic is obtained as the countermeasure of electromagnetic interference and current saturation hardly takes place. Thus, the manufacture man-hour and the manufacture cost in the forming of the coil are reduce and the characteristic is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a noise filter, and more particularly, to a noise filter that can reduce manufacturing man-hours and improve characteristics.

[Conventional technology]

FIG. 3 shows the configuration of a conventional noise filter used in various electric circuits such as electronic equipment.

This noise filter is formed by separately winding the conductive wires 1 and 2.3 connected between the terminals U-R, V-3, and W-T around the annular magnetic core 4, using so-called split winding. ing.

[Problem to be solved by the invention]

However, in the structure of the noise filter described above, more than 1/3 of the man-hours for manufacturing the noise filter are spent on forming a coil in which a conducting wire is wound around an annular magnetic core.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a noise filter that can reduce the number of manufacturing steps described above, reduce manufacturing costs, and improve characteristics.

[Means to solve the problem]

In order to achieve the above object, the noise filter of the present invention is formed by winding a plurality of conducting wires around an annular magnetic core, in which covered conducting wires are used as the plurality of conducting wires, and these covered conducting wires are twisted. They are characterized in that they are wound around the annular magnetic core in a combined state.

[For production]

Therefore, the number of man-hours required to form a coil by winding the conductor around the annular magnetic core is reduced to one time, and the number of man-hours required for forming the coil is one time.
/2, three-phase becomes 1/3. Further, if the stranded wire is evenly wound around the entire circumference of the annular magnetic core, leakage magnetic flux is almost eliminated and current saturation is also less likely to occur, so that the characteristics as a coil are improved.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on an embodiment shown in the drawings.

The noise filter 10 of the present invention includes U-R, V-5, W-
As each conductor wire 11°12.13 connected between each terminal of T, use a coated conductor wire insulated with a coating having high dielectric strength between each conductor wire, such as a polyester-coated copper wire, and these coated conductor wires 11.12 .13 are twisted together in advance to form a stranded wire 14, and this stranded wire 14 is wound around an annular magnetic core 15 to form a coil.

By making the conducting wires wound around the annular magnetic core 15 into the twisted wires 14 in advance in this way, the number of steps required for forming the coil can be reduced to one time. Therefore, it is possible to reduce the number of man-hours by 1/2 for single-phase and 1/3 for three-phase.

Furthermore, by uniformly winding the stranded wires 14 around the entire circumference of the annular magnetic core 15 (ferrite core), leakage magnetic flux is almost eliminated, good characteristics as a countermeasure against electromagnetic induction are obtained, and the annular magnetic core 15 of the same size Current saturation is also less likely to occur compared to conventional noise filters using noise filters.

For example, as is clear from the noise terminal voltage data of the noise filter formed by winding the stranded wire 14 shown in FIG. 2 and the noise terminal voltage data of the conventional noise filter shown in FIG. The noise filter used was 10-1
In the harmonic band of 50kHz, 10
~30 dBμ■ is attenuated, and a great effect is obtained for the harmonic band.

Note that the wiring and circuit configuration other than the above-mentioned coil portion can be formed in the same manner as various conventional noise filters, so detailed explanation thereof will be omitted.

〔Effect of the invention〕

As explained above, since the noise filter of the present invention is made by twisting a plurality of covered conductors and winding them around the annular magnetic core, it is possible to reduce the number of man-hours for forming the coil, reduce manufacturing costs, and By uniformly winding the stranded wires, leakage magnetic flux is almost eliminated, and current saturation is also less likely to occur, so characteristics can be improved.

[Brief explanation of the drawing]

FIG. 1 is a front view of a noise filter showing an embodiment of the present invention, FIG. 2 is a noise terminal voltage data of the noise filter shown in FIG. 1, and FIG. 3 is a front view showing an example of a conventional noise filter. FIG. 4 shows noise terminal voltage data of the noise filter shown in FIG.

Claims (1)

[Claims] 1. A noise filter formed by winding a plurality of conducting wires around an annular magnetic core, characterized in that covered conducting wires are used as the plurality of conducting wires, and these covered conducting wires are twisted and wound around the annular magnetic core. Noise filter.