JPH0797532B2 - Winding method of choke coil for noise filter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise filter choke coil represented by a common mode choke coil, and more particularly to a winding method for winding a coil wire around an annular core.

[0002]

2. Description of the Related Art In a common mode choke coil, a winding part of an annular core is equally divided into two parts, and coils having the same number of turns are symmetrically wound on both parts so that magnetic fluxes generated by both coils cancel each other. It was done like this. If the annular core is large enough for the required number of coil turns,
It is possible to wind a coil with the required number of turns without winding the wires in layers (this is called straight winding). However, if the number of turns required for the size of the winding part of the annular core is very large, or if the wire material is very thick, straight winding cannot get the required number of turns, and the wire parts should be wound in layers. become. When the coil is wound by lap winding, the stray capacitance becomes very large due to the overlapping of the wire materials. If the stray capacitance is large, the high frequency characteristics of the noise filter deteriorate.

Japanese Utility Model Publication No. 1-15147 discloses a technique for reducing stray capacitance and improving the characteristics of a noise filter choke coil in which a coil is wound by lap winding. As shown in FIG. 2, the winding part of the annular core 1 is divided into two equal parts by a partition plate arranged in the diametrical direction, and the two divided parts are respectively divided as follows.
Wind two coils. That is, one divided portion (half of the annular core 1) is divided into the first area 4a and the second area 4b, and the boundary portion between the two areas is set as the winding start position 3. Align the center part of the wire with winding start position 3 and place one side first
The area 4a is wound about one reciprocating half-lap, and the opposite side is similarly wound about one reciprocating half-lap on the second area 4b.

According to this winding method, the stray capacitance of the portion overlapped on the first area 4a and the stray capacitance of the portion overlapped on the second area 4b are connected in series, and the combined capacitance is their It will be about half. The stray capacitance is about 1/4 in the winding method of FIG. 2, as compared with the case where the same number of turns is simply made by one reciprocating half-lap winding over the first area and the second area.

[0005]

In particular, in the case of a noise filter choke coil which places importance on high frequency characteristics, the winding method of FIG. 2 is not sufficient. The purpose of the present invention is shown in FIG.
It is another object of the present invention to provide a method for winding a choke coil for a noise filter, which has a smaller stray capacitance than that of the above winding method and can realize better characteristics in a high frequency region.

[0006]

Therefore, in the present invention, when the winding portion of the annular core is equally divided into a plurality of coils and one coil is wound on each divided portion, one divided portion is divided into three areas. The resonance frequency is changed by first winding the wire rod in the central area for one reciprocating half-lap and then for winding both end sides of the wire rod in the areas on both sides of the central area for one reciprocating to one reciprocating half-lap. I was allowed to.

[0007]

Since the stray capacitances of the respective parts divided into the three areas and wound are the combined capacitances in the form of being connected in series, if the stray capacitances of the respective areas are equal, the synthetic capacitance is three times that amount. The combined capacitance is about 1/9 of the stray capacitance in the case of simply overlapping and winding over three areas. Also, it is possible to change the resonance frequency.
High impedance characteristics especially in the high frequency range
Can have.

[0008]

FIG. 1 shows an embodiment of the present invention. The winding portion of the annular core 1 is divided into two equal parts by the partition plate 2 arranged in the diametrical direction, and one coil is wound in each of the two divided portions as follows.

About half of the annular core 1 is further divided into three parts.
Almost equally divided into one area 5a, 5b, 5c. First, the vicinity of the center of the wire is aligned with the second area 5b at the center, and the wire is wound back and forth in this area 5b once and half. Then, both sides of the wire are located on the first area 5a side and the third area 5c side, respectively. Therefore, one end side of the wire is placed in the first area 5a.
Reciprocating to 1 reciprocating half-lap winding, and the other end side is the third area 5
One reciprocating to one reciprocating half-lap winding on c. This completes the winding of one coil. Another coil is wound in the same manner in the remaining half area of the annular core 1.

In this way, the wire is wound around the second area 5b at the center for one reciprocating half-lap, and the wire is further wound around the first areas 5a and 5c on both sides. It is short and very easy to work with. Also, there is a choke coil that uses this winding method.
Can change the resonance frequency, especially high frequency
Can have high impedance characteristics in the region
Wear.

The winding method of the present invention can be similarly applied to a three-phase three-wire noise filter or a three-phase four-wire noise filter choke coil.

Using the same annular core and wire material, the common mode choke coil manufactured by the conventional winding method shown in FIG. 2 and the common mode choke coil manufactured by the winding method of the present invention shown in FIG. 1 (the number of turns is the same). A characteristic comparison experiment was performed. The noise filter shown in FIG. 3 was constructed using this common mode choke coil, and the frequency / impedance characteristics of the coils L1 and L2 were measured. The result is shown in FIG. 6 for choke coil by conventional winding method
Resonance points appear near MHz and 20 MHz, but the choke coil according to the winding method of the present invention maintains a sufficiently high impedance even in this frequency band. Further, the noise filter shown in FIG. 3 was connected to a switching power supply as a noise source, and its noise attenuation characteristics were compared and tested. The results are shown in FIGS. As is clear from the experimental results, the noise reduction effect, particularly the noise reduction effect in the high frequency region, is superior when the choke coil according to the winding method of the present invention is used.

[0013]

According to the present invention, the winding portion of one coil is divided into three areas, and first the wire rod is placed in the central area.
The wire rod is wound back and forth half-lapped, and both ends of the wire are wound once to one back-and-forth half-lapped on both sides of the central area. Therefore, the stray capacitance of the windings in each area becomes a combined capacitance in the form of three connected in series, and the stray capacitance as a whole is very small, compared to a simple winding wound around one coil winding part. The stray capacitance is reduced to about 1/9. As a result, the characteristics in the high frequency region are improved. Also, since the wire rod is wound from the central area, the winding work is very easy. Also, this winding method
The choke coil with
High impedance, especially in the high frequency range
Can have dance characteristics.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a winding method according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a conventional winding method.

FIG. 3 is a diagram showing a circuit name of a noise filter using a common mode choke coil.

FIG. 4 is a comparison diagram of impedance / frequency characteristics of a choke coil according to a conventional winding method and a choke coil according to a winding method of the present invention.

FIG. 5 is a noise attenuation characteristic diagram of a noise filter using the choke coil according to the conventional winding method and the choke coil according to the winding method of the present invention.

[Explanation of symbols]

 1 annular core 2 partition plate 3 winding start position 4a 1st area 4b 2nd area 5a 1st area 5b 2nd area 5c 3rd area

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masami Nonaka 5 36-11 Shinbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd. (72) Yoshihiro Mochizuki 5 36-11 Shinbashi, Minato-ku, Tokyo Fuji Denki Kagaku Co., Ltd. (56) Bibliography Jikkyohei 1-15147 (JP, Y2)

Claims (1)

[Claims] 1. A winding part of an annular core is equally divided into a plurality of parts,
When winding one coil on each divided part,
One of the divided parts is divided into three areas, and a wire rod is first wound around the central area for one reciprocation and a half, and then both end sides of the wire material are reciprocated to one and a half round trips to both sides of the central area. Resonant frequency changed by overlapping
A method for winding a choke coil for a noise filter, characterized in that: