JPH0134430Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an ultrahigh-speed variable delay line whose delay characteristics can be changed by combining an inductor and a capacitor.

Conventionally, this type of variable delay line has been constructed by providing a fixed contact array on an inductor formed by forming a conductor strip in the shape of a solenoid on a bobbin, and slidingly contacting a sliding spring as a movable contact with the fixed contact array. By sliding the sliding spring along the fixed contact row,
It has a structure in which single contact between an individual fixed contact and a sliding spring and double contact between adjacent fixed contacts and a sliding spring are alternately switched by dropping the sliding spring between adjacent fixed contacts.

After the sliding spring has selected a predetermined fixed contact, a biasing force is applied to the sliding spring to prevent the fixed contact from moving due to vibrations, shocks, etc. applied to the variable delay line and changing the characteristics. The top is sliding.

Further, as shown in FIG. 1, each fixed contact 2a, which constitutes the fixed contact row 2 formed on the bobbin 1,
2b, 2c... are formed by forming a nickel plating layer 4 on the conductor strip 3 and further forming a plating layer 5 to suppress corrosion of the conductor strip 3 and keep the contact resistance with the sliding spring low. ing.

However, in the variable delay line configured in this way, as shown in FIG.
2b, 2c..., and double contact by dropping the sliding spring 6 between adjacent fixed contacts 2a, 2b, 2c..., so that the sliding spring 6
When the fixed contacts 2a, 2b, 2c... fall between the fixed contacts 2a, 2b, 2c... or ride on the fixed contacts 2a, 2b, 2c..., the upper edge of each fixed contact 2a, 2b, 2c... wears out and the conductor An exposed inclined portion 8 of the strip 3 is likely to be formed.

Moreover, since the conductor strip 3 is formed of a good electrical conductor such as copper, an oxide film is likely to form on the sloped portion 8 of the conductor strip 3, resulting in increased contact resistance with the sliding spring 6, resulting in increased loss and It has the disadvantage of causing instability of the delay characteristics, and in extreme cases may lead to inoperability due to poor contact.

In particular, the fixed contacts 2a, 2 adjacent to the sliding spring 6
Contact failure is likely to occur when making multiple contacts with b and 2c,
It is difficult to ensure good multiple contact conditions.

In addition, when the upper edges of the fixed contacts 2a, 2b, 2c... wear out, the sliding spring 6 also wears out, which deteriorates the surface condition of the sliding spring 6 and accelerates the deterioration of the delay characteristics. be.

The present invention was developed to solve these conventional drawbacks, and it is possible to reduce wear on the fixed and movable contacts, and to keep the contact resistance between the fixed and movable contacts stable and low over time. The purpose of this invention is to provide an ultra-high-speed, compact variable delay line whose delay characteristics can be switched stably and reliably.

To achieve this objective, the present invention includes an inductor, a capacitor that is combined with the inductor to form a delay line, a fixed contact array formed on the inductor, and a movable contact that slides on the fixed contact array. In a variable delay line consisting of a fixed contact, a sloped portion is formed at the upper end edge of the fixed contact that is in contact with the movable contact, and the movable contact is formed so that it simultaneously contacts both sloped portions of the adjacent fixed contact, and the sloped portion A conductive protective layer with good corrosion resistance is formed on the above-mentioned fixed contact, which suppresses wear and chemical changes on the upper edge of the fixed contact caused by sliding of the movable contact. be.

The details of the present invention will be explained below. Note that parts common to the conventional example are given the same reference numerals.

FIG. 3 is a longitudinal sectional view showing an embodiment of the present invention. Reference numeral 1 designates a rod-shaped non-magnetic bobbin with a rectangular cross section, which is placed horizontally and has a ground electrode 9 formed on its upper surface in the longitudinal direction, and a dielectric layer 1 on the ground electrode 9.
0 is formed.

On the outer periphery of the bobbin 1, an inductor 11 is formed by space-wound conductor strips 3 made of copper at a predetermined pitch in the shape of a single-layer solenoid.As shown in FIG. 4, there are recesses between adjacent conductor strips 3. It has become a department. In the inductor 11, a capacitance C is formed in each turn of the inductor 11 by the conductor strip 3 on the dielectric layer 10 and the ground electrode 9 facing the conductor strip 3, with each turn being connected to the conductor strip 3. A lumped constant type delay line 12 is constructed of a plurality of sections in which the inductance L for each section is combined with the capacitance C thereof.

Further, the conductor strip 3 of the inductor 11 has sloped portions 13 at both upper end edges, and a nickel plating layer 4 is formed on the upper surface of the conductor strip 3 including the sloped portions 13, and further on the nickel plating layer 4. A gold plating layer 5 is formed.

The upper conductor strip 3 of the inductor 11 has fixed contacts 2a, 2b, 2c, . Thus, a fixed contact array 2 is configured. Incidentally, the inclined portion 13, the nickel plating layer 4, and the gold plating layer 5 in the conductor strip 3 can also be formed at or near the portion where the sliding spring 6 contacts, and if the formation location is limited, each plating layer 4 can be formed. , 5 materials can be saved.

In FIG. 3, the lower surface of the bobbin 1, that is, the surface opposite to the surface on which the capacitor C is formed, is fixed to the inside of the bottom 15 of the casing 14, and the ground electrode 9 passes through the vicinity of both end surfaces of the bobbin 1 to the bottom of the casing 14. The winding end of the conductor strip 3 of the inductor 11 is connected to an output terminal 18 that is similarly planted on the bottom 15. Note that the beginning of the winding of the conductor strip 3 is connected to the input ground terminal 16 via a terminating resistor.

The housing 14 has a sliding electrode 20 formed along the fixed contact row 2 of the bobbin 1 inside the ceiling part 19, and the sliding electrode 20 is formed along the fixed contact row 2 of the bobbin 1.
The input terminal 21 is connected to the input terminal 21 installed in the input terminal 21 .

A spring holder 23 with a knob is disposed on the ceiling 19 of the housing 14 and has a knob 22 protruding from a sliding groove 21 provided in the ceiling 19 along the fixed contact row 2. is a housing section 24 formed to open in two directions of the fixed contact array.
A variable delay line is constructed by housing a sliding spring 6 that contacts the sliding electrode 20 and the fixed contact array 2 in a biased state. The sliding spring 6 is formed by curving or bending a band-shaped conductor that is relatively hard and easy to work with, such as beryllium copper, to form, for example, an inverted mountain shape, and is optionally coated with a plating layer (with good corrosion resistance). (not shown).

FIG. 5 is an equivalent circuit diagram of the above-mentioned variable delay line, where the symbol PG is a pulse signal source, C _s is a stray capacitance,
L _w represents the coupling inductance of the sliding electrode 20, the sliding spring 6, etc., R _p represents the terminating resistance, and a represents the coupling coefficient between each turn of the inductor 11.

This variable delay line is connected to the knob 2 of the spring holder 23.
2 within the sliding groove 21 of the housing 14, the sliding spring 6 contacts the sliding electrode 20, and the individual fixed contacts 2a, 2b, 2 of the fixed contact row 2 are moved.
Single contact with c... and adjacent fixed contacts 2a, 2
b, 2c... By recessing into the recessed portion between adjacent fixed contacts 2a, 2b, 2c, the multiple contact points with the inclined portion 13 are repeatedly slid and switched, changing stepwise with a predetermined narrow time difference. This results in variable delay characteristics.

The variable delay line configured in this way has individual fixed contacts 2a, 2b, 2c constituting the fixed contact array 2.
. . . has an inclined portion 13 in advance at least on the upper end edge that the sliding spring 6 contacts, so that the sliding spring 6
When the fixed contacts 2a, 2b, 2c... are depressed, or when the fixed contacts 2a, 2b, 2c... ride on the upper surface, they are not easily worn, and the fixed contacts 2a, 2b, 2c... including the inclined portion 13 are not easily worn out. Since... is covered with the nickel plating layer 4 and the gold plating layer 5, it is more difficult to wear and has good corrosion resistance.

Therefore, it is possible to keep the contact resistance between the sliding spring 6 and the fixed contact array 2 low over time, and not only can stable delay characteristics be obtained, but also reliable switching can be achieved.

Note that in the above implementation, the inductor 11
In this example, bobbin 1 is used as bobbin 1.
It is also possible to omit the conductor strip 3, and even when using the bobbin 1, it is not limited to the bobbin 1 in which the conductor wire is wound. A solenoid-like conductor strip 3 can be formed by forming a layer and using photoetching or a laser beam.

However, in order to ensure the stability of the sliding spring 6 on the fixed contacts 2a, 2b, 2c, . . ., the conductor strip 3 in the present invention is suitably a rectangular wire-shaped conductor strip with a flat upper surface, for example. The inclined portion 13 formed at the upper end edge of the conductor strip 3 can be easily formed by a pressure method or a chemical method such as corrosion before forming the plating layers 4 and 5.

Furthermore, the nickel plating layer 4 formed on the conductor strip 3 may be selected depending on the material of the conductor strip 3.
Although the object of the present invention can be achieved by plating with a conductive material having good wear resistance, it may be omitted depending on the material of the conductor strips 3. The plating layer 5 formed on the nickel plating layer 4 may be formed of a conductive material with good corrosion resistance, such as gold, as a protective layer.

As explained above, in the variable delay line of the present invention, in the fixed contacts provided in the inductor, an inclined part is formed at the upper edge of each adjacent fixed contact that the movable contact simultaneously contacts, and the fixed contact including this inclined part is Since a conductive protective layer with good corrosion resistance is formed on the contact, chemical changes such as wear and oxidation of the fixed contact and the movable contact are small, and contact resistance can be kept low. In particular, it is possible to ensure the stability of the movable contact and to improve poor contact during multiple contacts.

Therefore, it is possible to obtain stable and good delay characteristics over time, and it is possible to reliably switch the delay time.

[Brief explanation of the drawing]

1 and 2 are partial sectional views showing a fixed contact array of a conventional variable delay line, and FIGS. 3 and 4 are longitudinal sectional views showing an embodiment of the variable delay line of the present invention and its fixed contacts. FIG. 5, which is a partial cross-sectional view showing the column, is an equivalent circuit diagram of the variable delay line. 1...Bobbin, 2...Fixed contact row, 2a, 2
b, 2c... fixed contact, 3... conductor strip, 4... conductive layer with good wear resistance (nickel plating layer), 5
...Conductive protective layer (gold plating layer) with good corrosion resistance,
6... Movable contact (sliding spring), 8, 13... Inclined portion, 11... Inductor, 12... Lumped constant type delay line.

Claims (1)

[Claims for Utility Model Registration] (1) An inductor, a capacitor that forms a delay line in combination with the inductor, a fixed contact array formed on the inductor, and a movable contact that slides on the fixed contact array. , in a variable delay line in which an arbitrary fixed contact is selected from the fixed contact array to change the delay characteristic by sliding the movable contact,
forming a sloped portion on the upper end edge of the fixed contact that the movable contact contacts, and forming the movable contact so that it simultaneously contacts both sloped portions of adjacent fixed contacts;
A variable delay line characterized in that a conductive protective layer having good corrosion resistance is formed on the fixed contact including the inclined portion. (2) The variable delay line according to claim (1), wherein the conductive protective layer with good corrosion resistance is formed through a conductive layer with good wear resistance.