JPH0238416Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a current-controlled variable inductor used in electronic tuning circuits such as circuiters and variable delay lines.

[Prior art and its problems]

FIG. 3 is an explanatory diagram of a conventional current controlled variable inductor, which was filed by the present applicant as Japanese Patent Application No. 14822/1982.

A control coil 2 is wound around the first core 1, and a second core 5, around which a tuning coil 4 is wound, is inserted into a hollow portion 3 provided in the winding portion. Furthermore, the first core 1 is covered with a pot-shaped third core 6. 7 is the first core 1 and the second core 5
is placed thereon, and the third core 6 is fitted into the base, and 8 is a terminal pin. control coil 2
The magnetic path by the tuned coil 4 extends from the first core 1 to the third core 6 as represented by the dotted line 9, and the magnetic path by the tuned coil 4 extends from the second core 5 to the first core as represented by the dotted line 10. 1, but both magnetic path 9 and magnetic path 1
0 overlaps the most in the winding portion 11 of the second core 5. Then, the second
It is possible to control the effective magnetic permeability of the core 5 and change the inductance of the tuning coil 4.

However, with the structure shown in Figure 3, once the assembly is completed,
It is not possible to change the constants of the overall characteristics, such as the maximum and minimum values of inductance and Q values, as well as the slope of changing these values. Therefore, if it is necessary to adjust the constant of the variable inductor in a circuit, it cannot be used, and it is not practical to redesign it from scratch and replace it each time.

〔the purpose〕

The object of the present invention is to provide a current-controlled variable inductor that allows the constants of the characteristics to be adjusted by making the core around which the tuning coil and control coil are wound relatively movable even after assembly. Our goal is to provide the following.

[Technical means to solve problems]

In the current controlled variable inductor of the present invention, the first core around which the control coil or the tuning coil is wound has a hollow part in the winding part, and the bottom surface of the pot-shaped third core has a hollow part in the winding part. is stored vertically inside the second coil, and the remaining coil is wound around the second coil.
The core is supported in the hollow part so as to be movable up and down, with its winding part where the magnetic paths of the control coil and the tuning coil overlap, being parallel to the winding part of the first core. shall be.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the current controlled variable inductor of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is an explanatory longitudinal cross-sectional view, and FIG. 2 is an exploded perspective view showing the coils removed.

In FIGS. 1 and 2, 20 and 21 are a first core and a second core, respectively, and 22 and 23 are a pot-shaped third core.
and a fourth core, both of which are made of ferrite, which is a magnetic material. The first core 20 and the third core 22 are made of ferrite suitable for low frequencies, and the second core 21 and fourth core 23 are made of ferrite suitable for high frequencies, which are used at the frequency of the current flowing through the tuning coil, which will be described later.

A base 24 and a screw 26 screwed into the hole 25
is made of synthetic resin.

The first core 20, which has circular flanges at both ends, has a hollow portion 28 having a circular cross section in its winding portion 27, passing through the upper and lower flanges 29 and 30. Winding part 2
A control coil 31 is wound around 7.

A through hole 33 having the same size as the cross section of the hollow portion 28 is provided in the center of the bottom surface 32 of the third core 22 .

The first core 20 connects the hollow portion 28 to the third core 22
The winding portion 27 is aligned with the through hole 33 of the bottom surface 32.
It is housed in the third core 22 in a state perpendicular to . Although the third core 22 is fitted into the side surface of the base 24, the first core 20
held on top.

The fourth core 23 is fitted into the hollow part 28.

A tuning coil 35 is wound around the winding part 34 of the second core 21, which has circular flanges at both ends.
The core 23 is inserted into the hollow part 28 while being covered by the core 23. The upper flange 36 is fixed to the bottom surface 37 of the fourth core 23. The lower flange 38 is connected to the upper end 3 of the screw 26 which is screwed into the center hole 25 of the base 24.
By rotating the screw 26, the second core 21 moves up and down together with the fourth core 23 within the hollow portion 28 and the through hole 33. Of course, even if the screw 26 rotates, the second core 21 fixed to the fourth core 23 does not rotate. In order to prevent the second core 21 and the fourth core 23 from rotating due to the rotation of the screw 26, the cross section of the hollow part 28 of the first core may be made square instead of circular, or a part of the inner periphery may be made square. A rotation preventing means may be provided, such as providing a groove in which a protrusion that prevents rotation of the fourth core 23 and the second core 21 is fitted.

Note that the step surface 40 of the base 24 is one step lower.
is provided to increase the vertical movement distance of the fourth core 23. 41 is a terminal pin for connecting the lead wires of the control coil 31 and the tuning coil 35, and 42 is a groove through which the lead wires are passed.

The contact surface between the upper flange 29 of the first core 20 and the bottom surface 32 of the third core 22 , the fixed surface between the upper flange 36 of the second core 21 and the bottom surface 37 of the fourth core 23 , Mylar film or the like may be sandwiched between the inner surface 43 and the lower flange 30 of the first core 20 in order to improve stability of properties and physical strength.

In the variable inductor of the present invention configured in this manner, the magnetic path 45 formed by the control coil 31 includes the winding portion 34 of the second core 21, the bottom surface 37 of the fourth core 23, and the third The core 22, the lower flange 30 of the first core 20, the inner surface 44 of the fourth core 23,
It mainly extends to the lower collar 38 of the second core 21 . On the other hand, the magnetic path 46 by the tuned coil 35 connects the second core 21
winding part 34, fourth core 23, second core 21
It mainly extends to the lower tsuba 38 of. The magnetic path 45 and the magnetic path 46 overlap most in the winding part 34 of the second core 21, and by changing the magnetic flux density by the control coil 31, the effective magnetic permeability of the second core 21 is controlled. Inductance and Q of tuning coil 35
can be adjusted. Moreover, by moving the position of the tuning coil 35 using the screw 26 and changing the extension state of the magnetic path 45 and the magnetic path 46, the maximum and minimum values of inductance and Q, as well as the degree of change thereof, can be changed as a whole. The constants of the characteristics can be adjusted.

In the embodiment, the position of the fourth core 23 is determined by the maximum and minimum values of inductance and Q, and the position of the second core 21.
The position of each greatly affects the variable ratio, which is the value divided by the maximum and minimum values. Note that the fourth core 23
By extending the magnetic path 46 of the tuning coil 35 into the core for high frequency, it also has the role of reducing high frequency loss and maintaining the above characteristic value largely up to high frequencies, and has the role of maintaining the above characteristic value to a large extent up to high frequencies. It may be excluded when used at low frequencies. If metal is used for the fourth core 23, the precision of the shape is improved compared to ferrite.

Moreover, the hollow part 28 of the first core 20 and the third core 2
Although the hole 33 in FIG. 2 is penetrating, the hollow part 3 in FIG.
The second core may be moved only within the hollow portion of the first core without penetrating it like the third core 6 or the third core 6. Furthermore, the positions of the tuning coil and control coil can also be exchanged. There may be a plurality of inner tuning coils. Another screw in addition to the screw 26 is provided, and the fourth core 2 is connected by the other screw.
3 can also be moved independently of the second core 21.

〔effect〕

As described above, the current controlled variable inductor of the present invention moves the relative positions of the control coil and the tuning coil so that the windings are parallel to each other.
By changing the magnetic path of each coil and the state in which they overlap, the constants of the overall characteristics can be adjusted. Therefore, after assembly, the range in which the characteristics can be matched to the circuit constants without new design changes is expanded, and this is practical in that it can provide a wide range of versatility.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a current-controlled variable inductor of the present invention, FIG. 2 is an exploded perspective view, and FIG. 3 is an explanatory view of a conventional current-controlled variable inductor. 20...first core, 21...second core, 2
2...Third core, 23...Fourth core, 24...
...base, 25...hole, 26...screw, 27,3
4...Winding part, 28...Hollow part, 29, 36...
Upper flange, 30, 38...Lower tsuba, 31...Control coil, 32, 37...Bottom surface, 33...Through hole, 35
... Tuning coil, 39 ... Upper end, 40 ... Step surface, 43, 44 ... Inner surface, 45, 46 ... Magnetic path.

Claims (1)

[Scope of utility model registration request] The first coil around which the control coil or tuning coil is wound.
The core has a hollow part in the winding part, and the winding part is housed inside so that it is perpendicular to the bottom surface of the pot-shaped third core, and the remaining coils are wound therein. The second core is supported in the hollow part so as to be movable up and down, with the winding part of the second core overlapping the magnetic paths of the control coil and the tuning coil being parallel to the winding part of the first core. A current controlled variable inductor featuring: