JPH04249007A - Choke coil type cable - Google Patents

Abstract

PURPOSE:To provide a choke coil type cable having high level high frequency inductance for effectively cutting noise by winding a wire rod of metal conductor around a core material including ferromagnetic body. CONSTITUTION:A moving ferromagnetic core material is formed of ferromagnetic amorphous alloy or a soft iron of special composition. Or otherwise, a rod is used by mixing a dust core or ferrite powder with an insulating organic high polymer. A copper wire 2 is wound around a core material 1 from aggregation in a spiral manner. Two core materials are used and the directions of the winding of the copper wire 2 is reversed to each other so as to prevent the magnetic flux leakage from the core material. The entire body is covered with an insulating coating 3. A noise filter is thus manufactured at lower cost than the one for which a normal choke coil is used.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] Wiring materials for power cords of electronic devices

[
0002

2. Description of the Related Art As electronic devices have become more digitalized in recent years, the risk of malfunction due to various noises has increased. In particular, a major cause is that high frequency noise generated from other electronic devices flows in through the household AC power supply. Therefore, in order to prevent the inflow of noise from the power supply system, it is common practice to apply noise prevention measures to the power cord or to install a noise filter in front of the power supply circuit.

[0003] In order to prevent noise in the power cord, it is possible to increase the high-frequency inductance of the internal wiring material by mixing a ferromagnetic material such as ferrite into the coating material of the cord's constituent materials. This is commonly done. However, with this method, the amount of increase in inductance is small, so high frequency noise can only be reduced by about 9 decibels. In reality, the meaning of shielding from external electromagnetic waves is greater. However, since it is easy to manufacture, it can be manufactured at a low price.

A noise filter for a power supply circuit has a coil wound around a ferrite ring as its main component, and its main principle of operation is to attenuate high-frequency noise by degrading high-frequency characteristics through its high-frequency inductance. This point is similar to the previous technology of mixing ferromagnetic materials such as ferrite into the cable sheathing material, but
Since the amount of increase in high frequency inductance is overwhelmingly large, the amount of attenuation of high frequency noise can be increased to 40 decibels or more. However, this requires one to several choke coils depending on the type of noise to be removed, and is expensive. Additionally, space is required to install the filter inside the device, which poses an obstacle to downsizing the device. Note that high frequency noise here refers to noise of 100 kilohertz or more.

[0006]

[Problems to be Solved by the Invention] The present invention makes it possible to attenuate high frequency noise by 40 decibels or more by designing the wiring material itself as a choke coil and providing the wiring material itself with a high level of high frequency inductance. As a result, it is an object of the present invention to contribute to reducing noise removal costs and miniaturizing electronic devices using the wiring material according to the present invention.

[0007]

[Means for Solving the Problems] A choke coil is constructed by winding a metal conductor in a spiral around a ferrite ring made by firing ferrite powder, which is a ferromagnetic material.

In other words, it has a structure in which a ferromagnetic material in the center is used as a core material and a conductor is wound around it. The shape of the ferromagnetic material does not have to be circumferential like a ferrite ring, but may be linear.

However, leakage of magnetic flux from both ends of the linear magnetic material must be prevented.

For this purpose, it is necessary to install the two AC wires close to each other and magnetically couple the two wires.

Ferrite, which is suitable as an industrial ferromagnetic material, loses its flexibility when fired, and when a conductor is wrapped around it as a core material, it loses its flexibility as a wiring material. It cannot be used as such.

0012

The content of claim 1 is a method of manufacturing a wiring material in which a core material of a movable ferromagnetic metal is used instead of a normal ferrite ring and a metal conductor is wound around the core material.

[0013] A current is passed through the metal conductor portion. Do not connect both ends of the magnetic metal wire of the core material and the metal conductor.

[0014]

The content of [Claim 2] is that the resin wire is filled with ferromagnetic powder.

This is a substitute for the amorphous metal wire of claim 1, and this material also serves as a core material that has ferromagnetism, flexibility, and mobility.

[0015]

[Claim 1]

Both of the wiring materials according to claim 2 are coated with an insulating material on the outermost side.

[0016]

[Operation] A conductor surrounds a ferromagnetic material in the center,
Electrons flow inside a conductor. This structure is equivalent to a choke coil, and the high frequency inductance of the conductor increases significantly, increasing the high frequency AC resistance value. As a result, high frequency transmission characteristics deteriorate. As a result, the value of high frequency noise decreases.

The movable ferromagnetic metal used as the core material is both a ferromagnetic material and a conductor, but even if it is brought into direct contact with a metal conductor through which a current flows, the current will not flow from the metal through which the current flows. However, there is no practical problem in increasing the inductance. However, it is more effective to increase inductance by insulating one or both of the metal conductor through which current flows or the movable ferromagnetic metal used as the core material.

Therefore, if it is desired to increase the amount of increase in inductance, one or both of the metal conductor through which the current flows or the movable ferromagnetic metal used as the core material is completely removed.

[0019]

【Example】

For the mobile ferromagnetic metal in [Configuration Requirement 1], an amorphous alloy or soft iron with a special composition is used. Select a wire with a wire diameter of about 0.5 mmφ to 5 mmφ, or twist together thin wires with a smaller diameter to obtain the wire diameter as described above.

[0020]

[Configuration Requirement 2] When ferromagnetic powder is mixed into an insulating organic polymer and formed into a linear shape, the mixing rate of the ferromagnetic powder is set to a filling rate of 80% or less in terms of volume ratio. The wire diameter to be formed is 0.5m
The diameter should be mφ to 10 mmφ. Appropriate ferromagnetic powder is dust core or ferrite powder.

[0021] As for how to twist the metal conductor through which current flows and the core wire, it is preferable to wind the collective twists in a spiral.

[0022]

【Effect of the invention】

[Claim 1] and

By adopting the manufacturing method of claim 2, it is possible to manufacture a wiring material having a high degree of high frequency inductance, and at the same time, high flexibility and movability, and high frequency noise can be reduced by 40 decibels or more. Also, it can be manufactured at a lower cost than a noise filter that uses a normal noise-cutting choke coil.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a power cable using the wiring material according to claims 1 and 2;

FIG. 2 is a sectional view of a power cable using the wiring material according to claims 1 and 2.

[Explanation of symbols]

(1) Core wire made of ferromagnetic metal core material or insulating organic polymer mixed with ferromagnetic powder (2) Collectively twisted copper wire (3) Insulating coating

Claims (1)

[Scope of Claims] [Claim 1] (a) A metal conductor wire (2) is spirally wound around a ferromagnetic metal wire (1). (b) Ferromagnetic metal wire (1) and metal conductor wire (2)
Do not connect both ends. (c) Wiring material constructed as above and covered with insulating material (3). Claim 2: (a) Instead of the ferromagnetic metal wire (1), a wire (4) made by mixing ferromagnetic powder into an insulating organic polymer and forming it into a wire is used. [Claim 1] wiring material