JPS5897809A - Magnetic saturated variable inductor - Google Patents

Abstract

PURPOSE:To vary the magnetic bias and amplitude characteristic (saturation curve) and greatly improve the linearity characteristic, by moving a magnetized magnetic substance provided on the outer periphery of a drum core. CONSTITUTION:A coil 8 is wound up around the drum core 7 having flanges 7a, 7b at both end parts and mounted by fixing the flange 7b side of a terminal base 9 having terminal pins 9a. At one open end of the cylindrical magnetic substance 11 wherein a screw part 11a screwed into the screw part 10a of a case 10 is provided on the outer peripheral surface and the both ends are opened, a permanent magnet 12 is fixed so as to block this open end, and this magnetic substance 11 is provided on the outer peripheral part of the drum core 7. The permanent magnet 12 is magnetized N pole and S pole in a thickness direction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetically saturable variable inductor used for improving the horizontal linearity of television receivers and the like.

Recently, as the quality of television receivers has increased, it has become necessary to significantly improve the linearity characteristics of conventional television receivers, especially when used as monitors for computer terminals. In other words, distortion occurs horizontally on the left and right sides of the screen due to variations in the deflection yoke and deflection current. A coil is requested.

The conventional linearity coil that meets these demands has a structure as shown in Figure 1, in which the outer surface of the collar of the drum-shaped core 2 around which the coil 1 is wound has magnetic poles in the thickness direction. It has a structure in which a permanent magnet 3 is fixed by adhesive.

However, in the case of the conventional linearity coil shown in FIG. 1, due to variations in the drum core 2 and permanent magnet 3, the deflection current IDC and inductance L shown in FIG.
The characteristics (current superimposition characteristics) of the relationship between the current and current values varied greatly as shown by curves a and b, resulting in poor linearity correction, and it was not possible to fully meet the demands. In addition, in FIG. 2, the characteristic indicated by the solid line indicates the central value.

In order to solve these problems, a structure as shown in FIG. 3 has been considered.

In the conventional linearity coil shown in FIG. 3, a coil 4 is wound around a drum-shaped core 6, and the outer periphery of the drum-shaped core 6 is provided with flanges that bridge the gap between the flanges at both ends of the drum-shaped core 6. Permanent magnets 6 having magnetic poles are arranged side by side at the positions where the magnets rotate, and the amount of magnetic bias is changed by rotating the permanent magnets 6.

However, in the case of the linearity coil shown in FIG. 3, the current superposition characteristic is as shown in the curve 0.0 in FIG. As shown in d, sufficient linearity correction could not be performed because only the magnetic bias point was moved.

The present invention aims to solve these conventional drawbacks and to significantly improve linearity characteristics.

In order to achieve such an object, in the present invention, a cylindrical magnetic body with both ends open and movable in the height direction of the drum-shaped core is disposed around the outer periphery of the drum-shaped core around which the coil is wound. A permanent magnet is fixed to one open end of the magnetic material so as to close this open end. The magnetic bias and amplitude characteristics (saturation curve) are changed by moving a magnetized magnetic body disposed around the outer periphery of the mold core.

Hereinafter, an embodiment of the present invention will be explained using FIGS. 6 and 6, which show an embodiment of the present invention.

FIG. 6 shows a magnetically saturable variable inductor according to an embodiment of the present invention, and in FIG.
There is a +° ram type cocoa having a and 7b, and a coil 8 is wound around this drum type core 7. This drum-shaped core 7 has one flange T on a terminal block 9 having a terminal bin 9a.
It is attached by fixing the b side.

Reference numeral 10 denotes a cylindrical case in which the drum-shaped core 7 is housed, and the inner peripheral surface of this case 10 is provided with a threaded portion 10&.

Reference numeral 11 denotes a cylindrical magnetic body with both ends open, the outer peripheral surface of which is provided with a threaded portion 11a that is screwed into the threaded portion 101L of the case 1o. A permanent magnet 12 is fixed to cover the drum-shaped core 7, and the magnetic body 11 is disposed around the outer periphery of the drum-shaped core 7.

Further, the permanent magnet 12 is magnetized with N pole and S pole in the thickness direction.

That is, in the magnetically saturable variable inductor according to this embodiment, the cylindrical magnetic body 11 disposed on the outer periphery of the drum-shaped core 7 around which the coil 8 is wound is moved up and down in the height direction of the drum-shaped core 7. By doing so, the current superimposition characteristics are adjusted.

In this embodiment, when the magnetic body 11 is moved to approach the coil 8 wound around the drum-shaped core 7,
Since the magnetic path becomes a closed magnetic path, the saturation due to the current changes quickly, the saturation curve becomes steeper, and L becomes more susceptible to the influence of the permanent magnet 12, so the bias point also changes, resulting in curve E in Figure 6. It is a characteristic of Conversely, when the magnetic body 11 is moved away from the drum-shaped core 7, the magnetic path becomes an open magnetic path, so the saturation characteristics due to current change slowly, and the slope of the saturation curve becomes curve F in FIG. 6.

As described above, according to the variable magnetic saturation inductor of the present invention, variations in the amount of magnetization of the drum-shaped core can be absorbed by moving the magnetic body, and stable current superimposition characteristics can be obtained. . In addition, by changing the shape of the magnetic body in the height direction, the amount of magnetic flux applied to the magnetic structure changes, so the current superimposition characteristics can be set arbitrarily.
Furthermore, since the magnetic material is arranged around the outer periphery of the drum-shaped core, it is possible to obtain the effect that there is less leakage magnetic flux and less influence on the screen of the television receiver.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the schematic structure of a conventional 17 linearity coil, Fig. 2 is a current superimposition characteristic diagram of the coil, and Fig. 3 is a sectional view showing the schematic structure of another conventional linearity coil. Fig. 4 is a current superimposition characteristic diagram of the same coil, Fig. 6 is a sectional view showing a schematic configuration of a magnetically saturable variable inductor according to an embodiment of the present invention, and Fig. 6 is a current superimposition characteristic diagram of the same variable inductor. be. 7...Drum-shaped core, 8...Coil,
11...Magnetic material, 12...Permanent magnet. Name of agent: Patent attorney Toshio Nakao and 1 other person11
s 2 m 4th ffil a in Figure 115 in Figure 3 Figure 6 - Ipe' + Ivc

Claims (1)

[Claims] A cylindrical magnetic body with both ends open and movable in the height direction of the drum-shaped core is arranged on the outer circumference of the drum-shaped core around which the coil is wound, and this magnetic body is attached to one open end of the magnetic body. A magnetically saturable variable inductor with a permanent magnet fixed so as to close the open end.