JPH0427161Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a variable capacitor used for frequency tuning of wireless transceivers, high frequency measuring instruments, etc.

"Prior art" An example of a conventional variable capacitor used for frequency tuning of wireless transceivers and high-frequency measuring instruments is shown in Part 5.
As shown in the figure. As shown in the figure, the variable capacitor includes a stator 2 and a stator 2 between a pair of end plates 1.
It is composed of one corresponding rotor 3.

In a conventional variable capacitor having such a configuration, the maximum and minimum capacitance ratio determined by the amount of overlap between the electrode plates of the stator 2 and rotor 3 is approximately 12:
1, therefore, if the minimum capacitance is to be reduced in order to achieve wider-band tuning, it is necessary to switch from a variable variable capacitor with a large capacitance to a variable variable capacitor with a small capacitance.

Conventionally, for this purpose, as shown in FIG. 6, variable capacitors 5 and 6 of large and small capacities were used.
It was composed of stators 8 and 9 that shared an extended rotor shaft 7 and were arranged in large and small sections.

``Problem to be solved by the invention'' However, increasing the maximum and minimum capacitance ratio of the variable capacitor in such a conventional configuration not only increases the size of the variable capacitor and increases the cost, but also takes up space. There was a problem in that the counterpart device to be removed and attached also became larger.

The present invention was made with a focus on the problems in the conventional technology.
Another object of the present invention is to provide a variable capacitor that is compact, does not take up much space, and can be manufactured at low cost.

``Means for Solving the Problems'' The gist of the present invention for achieving the above object is as follows: A stator comprising electrode plates facing each other and arranged at intervals; A variable capacitor consisting of a rotor configured by arranging electrode plates that go in and out between the second electrode plates, wherein the stator is connected to a first stator having a plurality of electrode plates arranged, and a rotation of the rotor. The first one with the shaft in between.
a second stator formed by arranging a smaller number of electrode plates than the first stator at a position facing the stator; the rotor is a shared rotor, and the electrode plate is a shared rotor; It is possible to enter and exit the electrode plates of the first and second stators alternately, and when the electrode plate of the rotor is in a maximum overlap state with one stator, it is in a minimum overlap state with the other stator. The invention resides in a variable capacitor characterized in that it is arranged so that

"Operation" Since the first stator and the second stator are arranged within the rotating range of the shared rotor,
This means that a large capacity variable capacitor and a small capacity variable capacitor are configured within the same volume.

On the other hand, the capacitance ratio of this variable capacitor is the ratio of the maximum capacitance of a large capacitor to the minimum capacitance of a small capacitor, so it is much larger than the capacitance ratio of either variable capacitor alone. , can be used in wideband tuning circuits.

“Embodiment” An embodiment of the present invention will be described below based on the drawings.

1 to 4 show an embodiment of the present invention.

The variable capacitor 10 has square end plates 11 made of an insulating material at both ends.
On the rotor shaft 21 which is pivotally supported through the center of
A rotor 20 formed by fixing a large number of rotating electrode plates 22
and the fixing of the stator 31 of the first variable capacitor 30 provided on the two tie rods 31 that fix the end plates 11 at a large distance from each other, and the second variable capacitor 40 placed opposite to this stator 31. Child 41
It consists of.

As described above, the rotor 20 and stator 31 constitute a large-capacity first variable capacitor 30, and the rotor 20 and stator 41 constitute a small-capacity second variable capacitor 40. , the rotor 20 serves as a common rotor for both variable capacitors 30 and 40.

The rotor 20 consists of a rotor shaft 21 that is pivotally supported through the center of both end plates 11, and a large number of semicircular rotating electrode plates 22 made of thin aluminum plates arranged on the rotor shaft 21. A spacer 23 is inserted between the electrode plates 22, and each of these rotating electrode plates 2
2 are maintained at equal intervals. And rotor shaft 2
A rotor-side terminal 24 is provided in the vicinity of the outermost rotating electrode plate 22 of the end plate 11, with one end in sliding contact with the rotor shaft and the other end fixed to the inner wall of the end plate 11.

The stator 31 is composed of a rectangular fixed electrode plate 33 made of a thin aluminum plate and extending over the two tie rods 32.

A spacer 34 of the same size is inserted between each fixed electrode plate 33 on the tie rod 32, and holds each fixed electrode plate 33 at equal intervals, and the rotating electrode plate 22 is inserted between these fixed electrode plates. They are arranged so that they go in and out exactly in the middle of 33.

As shown in each figure, the stator 41 of the second variable capacitor 40 is connected to the tie rod 32 and the end plate 1.
A position facing the stator 31 with the rotor shaft 21 having the same shape as the fixed electrode plate 33 in between, on two fixed rods 42 planted at symmetrical positions on the fixed electrode plate 33 with spacers 44 equally spaced between them. A fixed electrode plate 43 is disposed at the top. The rotor 20 has an electrode plate 22 that can alternately move in and out of the electrode plates 33 and 43 of the first and second stators 31 and 41, and the electrode plate of the rotor 20 is attached to one of the stators. The stator is arranged so that when the stator is in the maximum overlap state, the stator is in the minimum overlap state with the other stator.

The tie rod 32 and the fixed rod 42 constitute stator side terminals 35, 45 of the first and second variable capacitors 30, 40, respectively.

Next, the action will be explained.

The terminal 24 on the rotor 20 side is grounded, and both stators 3
It is assumed that the respective terminals 35 and 45 of No. 1 and 41 are coupled to an inductance element L via an appropriate changeover switch S to construct a tuned circuit as shown in FIG.

When the rotating electrode plate 22 completely overlaps each electrode plate 33 of the stator 31 of the first variable capacitor 30 and the overlapping area is maximum, the first variable capacitor 30
Even as the variable capacitor 10, the capacitance is maximum.

From the above state, when the rotor shaft 21 is rotated to reduce the overlapping area, the capacitor capacitance decreases, and when the circuit constant reaches the tuning frequency, it is tuned.

If the tuning frequency cannot be found on the first variable capacitor 30 side, the changeover switch may be switched to the second variable capacitor 40 side to search for the tuning frequency.

The stators 31 and 41 are in exactly symmetrical positions,
When one side is in the maximum overlap state with the rotor 20, the other side is in the minimum state (geometric overlap area is zero), so the number of fixed electrode plates 33, 43 of both stators 31, 41 should be adjusted appropriately. By selecting
The capacitor capacitances of the first and second variable capacitors 30 and 40 can be formed into a smooth capacitance curve without any breaks, resulting in a single variable capacitor 10 with a large capacitance ratio that can be tuned over a wide band.

As shown in the figures, the variable capacitor 10 occupies the same space regardless of the presence or absence of the second variable capacitor 40.
A variable capacitor 10 with an extremely large capacitance ratio can be obtained.

"Effects of the invention" According to the variable capacitor of the invention, a large stator consisting of a large number of electrode plates and a small stator consisting of a small number of electrode plates are placed opposite each other via one common rotor. Because it is installed in such a way, a large capacity ratio can be obtained, and it is compact and does not take up much space.
The rotor electrode plate is arranged so that when it is in the maximum overlap with one of the first and second stators, it is in the minimum overlap with the other stator, so that the capacitance change can be reduced. It can be set appropriately, a smooth capacitance curve with no breaks can be obtained, and since only the second stator is added, an inexpensive variable capacitor can be obtained.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a vertical front view, FIG. 2 is a sectional view taken along the line -- in FIG. 1, FIG. The figure shows an example of the circuit configuration, Figures 5 and 6 show conventional variable capacitors, and Figure 5 is a perspective view of the external appearance.
FIG. 6 is a block diagram of a conventional increased capacity ratio type. 10... variable capacitor, 20... rotor, 2
1... Rotor shaft, 22... Rotating electrode plate, 30...
First variable capacitor, 31... Stator of first variable capacitor, 33, 43... Fixed electrode plate, 40...
...Second variable capacitor, 41...Stator of the second variable capacitor.

Claims (1)

[Claims for Utility Model Registration] A stator comprising electrode plates arranged facing each other and spaced apart from each other, and a rotor comprising electrode plates arranged so as to rotate in and out between the electrode plates of the stator. A variable capacitor comprising: a first stator in which a plurality of electrode plates are arranged;
a second stator formed by arranging a smaller number of electrode plates than the first stator at a position facing the stator, the rotor being a shared rotor, and the electrode plates being the same as the first stator. It is possible to enter and exit the electrode plates of the first and second stators alternately, and when the electrode plate of the rotor is in a maximum overlap state with one stator, it is in a minimum overlap state with the other stator. A variable capacitor characterized by being arranged so that