DE587305C - Procedure to compensate for the capacitance asymmetries of the core groups of telecommunication cables - Google Patents

Description

GERMAN EMPIRE

ISSUED ON NO YEMBER 2, 1933

REICH PATENT OFFICE

PATENT LETTERING

M 587305 CLASS 21c GROUP 4os

Patented in the German Empire on June 8, 1930

It is known the capacitive non-uniformities within the groups of four of Telecommunication cables by crossing them or by installing appropriately sized equalizing capacitors to eliminate.

The crossroads used in America

'ren suffers from the disadvantage that of the successive cable lengths only those Groups can be connected to one another, the links of which cancel each other. Through this it is possible to connect the groups at the connection points as they are next to each other. The comparison with Additional capacitors, on the other hand, have the disadvantage that additional capacitors at point-like points Switching means must be installed, which are relatively expensive.

Recently another method has become known which consists in special im Cable arranged wires to connect with the main wires. Here the between two this compensating cores, which are generally twisted into twin cores, acting partial capacitance used to compensate for the capacitive irregularities of the telephone wire groups. In this known cable, the compensating wires are either in special positions or in the same position with the telephone wire groups stranded. In any case, this arrangement causes an unnecessary increase in the cable diameter Additional costs for material is associated.

The invention is based on a method in which a smooth through-connection of the individual groups remains possible and the group with the supplementary resources of the individual forming cores can be used to compensate, without an increase in the cable diameter is necessary.

For this purpose z. B. each conductor of a S star group of four with an insulated metallic Head wrapped in a spiral. Above it is the paper tape in a known manner, which represents the core insulation, spun. The isolated, helically wound Metal conductor (compensating wire) thus replaces the insulating material of the known ones Cord loader. If you connect the conductor of this compensating core with the conductor of the main core, so the partial capacitance between this wire and the two directly adjacent Cores of a group of four, for example a star quad (Fig. 1), to one Increased amount, which depends on the length of the helically wound compensating wire.

The partial capacity is not increased by connecting the in parallel

*) The patent seeker stated as the inventor:

Dr. Hans Walter Droste in Nuremberg.

between two compensating cores existing capacity. Rather, the partial capacity is α between two wires and b by the compensation wires of these two wires in three parts, head a -Ausgleichsleiter a, compensation conductors a -Ausgleichsleiter b of the other "conductor b, bonding conductor b- conductor divided b (Fig. 2) and the Increase caused by short-circuiting one of these parts.

It is sufficient if the compensating cores described are only used over a short distance are present at the beginning or the end or at both ends of a length of cable. Since it is on is cheapest to use any capacitive coupling

! ■ 5 to balance the place of their existence, will to get closer to this state, the compensation points in the middle of each compensation section arrange.

If the actual conductor is spun with a compensating wire over a length of 10 m, the capacity increase is around 35 μμΈ when the compensating wire is connected to the actual conductor.

In order to be able to graduate the size of the capacitance change, several isolated Conductors must be wound around the main conductor side by side or one above the other. Covered, for example the longest compensating wire 10 m of the main conductor and another 9 compensating wires available, you can graduate the length of the remaining 9 compensating cores, for example, so that one is always around ι m shorter length of the main conductor is braided.

After measuring the capacitive coupling, you will now find that of the 10 wires connect to the actual conductor, the length of which is the most appropriate increase in the question coming partial capacity results.

FIG. 3 shows an exemplary embodiment of a conductor braided with insulated compensating conductors. 1 means this conductor, α the compensating wire, b a layer of paper wound over the conductor 1 to isolate the compensating conductor from the main conductor, and c the paper tape serving to isolate the wires.

In order to be able to differentiate between the individual compensating cores, it is recommended you to identify the insulating cover of one or two of them by special coloring. In this case, each compensating conductor has its own insulating sleeve.

From Fig. 2 it can be seen that all partial capacities between one core and all other cores can be increased if the partial capacitance between this core and one short-circuits their compensating cores.

On the other hand, you will only change the partial capacitance between two wires noticeably if the partial capacity between the two compensating cores of these cores by their metallic Connect shorts.

The capacity increase is especially great when using one of the actual conductors the compensating core of another core is connected.

In the following, the change that results from the merging of two compensating cores of different cores should be applied to several rere measurement examples are discussed.

A quad of 402 m in length originally had the coupling values

k _t = - 15, k ₂ = +224, Ze ₃ = 4-155,

e _x : = z -105, e ₂ = 4-215, e ₃ = +100, «,« F.

Now a compensating wire covering 5 m of the first wire was created Cotton braided 0.4 mm copper conductor, with a similar one, also 5 m opaque compensating core of the fourth core of the same quad connected by soldering. The final measurement resulted in the following values:

= - 175, k ₂ = + 37S. h - - 305, = - 105, e ₂ = -J-2i5, e _s = - \ - 100 μμΈ.

It can be seen that the earth capacities are not noticeably changed by the measure described. However, the partial capacity C _{14 has been} increased significantly, namely by 150. . . 151 μμΈ, as can be calculated from the known coupling equations. Since the couplings Is ₁ on the one hand and k ₂ and k _s on the other hand have changed by the mutually different amounts -160 and +151 or -—- i 50 μμΈ , one must conclude that the partial capacitances C ₁₃ and C _{24 are also included} have changed little. One can calculate that C _{13 has} decreased by 4.5 μμΈ and C ₂₄ by S μμΈ . This change is only 3.3 ° / ₀ of the change of C _14, thus not disturbing.

If there are several compensating conductors, insulated against each other, close to each other around each wire are spun that have different lengths, so you can, for example, by connecting a long compensating wire with one or more short many and achieve extraordinarily finely graduated changes in the partial capacity, as follows Measurements show results obtained.

If the equalizing core covering 5 m of core 1 was connected to a equalizing core covering 0.5 m of core 4, so the original values changed to:

h - - 43> h = +249> h = - 183, ^ = -105, e _g : = + 2i5, e _s - + 100 μμΈ.

One can conclude that C ₁₄ is 26.5 μμΈ larger and C ₁₃ is 1.5 μμΈ smaller iao. The compensating wire covering 5 m of the first wire was only 0.5 m of the fourth with four

The cores covering compensating cores were connected, so was:

k ₁ = z- 64, k ₂ = + 269, k _a = -200,
-e _t = - 105, <? ₂ = -j-2i5, i? 3 = +100

The changes were now +45 μμΈ _{for C 14} , and -2 μμΡ for C ₁₃ and C _{24 each.}

It has been shown that changes in capacitance below 15 μμΈ after this

equalization process cannot effect as easily as larger changes in capacitance that can generally be graded very finely. But you can feel very good about it help that you get all four partial capacities that are necessary for the capacity adjustment within the fours are important increases by a sufficient amount. So you will in this case not three but four partial capacities have to be increased by one to achieve full alignment.

Claims (7)

Patent claims: 1. Procedure to compensate for the capacity asymmetries the core groups of telecommunication cables, characterized in that the partial capacities of two Cores of the same or different groups through insulated metal inserts arranged between the conductor and its insulation divided into several partial capacities and changed by short-circuiting the partial capacities. 2. Metal insert to compensate for the capacity asymmetries of the core groups of telecommunication cables according to the method according to claim 1, characterized in, that it consists of an insulated, metallic conductor (compensating wire), the is wrapped around the conductor of the main line. 3. The method according to claim 1, characterized in that the increase in Partial capacities between the 4S with a compensating wire according to claim 2 see main wire and all other main wires by conducting a connection between the compensating wire and the conductor of the Main artery is achieved. 4. The method according to claim 1 and 3, characterized in that the wrapping of the conductor of a main line with compensating lines only on a shorter route takes place at the beginning or end or at both ends of a cable length or almost in the middle of a compensation section. 5. Metal insert for use in the compensation process according to claim 1, 3 and 4, characterized in that several compensating cores of the same or different lengths around each main conductor are helically wound in one layer next to each other. 6. The method according to claim 1, 3 and 4, characterized in that one or several of the compensating cores "to increase certain partial capacities with their own or other main conductors or be conductively connected to other compensating cores. 7. Telecommunication lead with metal inserts (compensating cores) according to claim 2 and 5, characterized in that the various arranged in one or more layers Compensating cores have insulating sleeves of different colors for the purpose of identification. 1 sheet of drawings