DE578379C - Arrangement for subordinate telegraphy with electrical sieve chains - Google Patents

Description

GERMAN EMPIRE

ISSUED ON JUNE 13, 1933

REICH PATENT OFFICE

PATENT LETTERING

'CLASS 21a ¹ GROUP 25

Siemens & Halske Akt.-Ges. in Berlin-Siemensstadt *)

Arrangement for subordinate telegraphy with electrical sieve chains

Patented in the German Empire on June 2, 1927

For many purposes e.g. B. in subordinate telegraphy (i.e. with simultaneous Telephoning and telegraphing on one line) it is necessary at certain Points of the circuit to attach coil chains. In underlay telegraphy, these coil chains have the purpose that To round off telegraph currents and to prevent telephone currents whose frequency is above the telegraph frequency, get into the telegraph machine.

The coil chains used in such circuits, the cores of which should, if possible, be designed as closed iron cores to reduce the number of turns and thus the copper losses of the coil, have the disadvantage that they generate harmonics. Because after . According to Raleigh's equation, the relationship between the magnetic field strength ξ> and the induction S3 in a coil with an iron core is given by the non-linear relationship S3 = / ίο · ξ> + ν · ξ? given, where μ _{α is} the initial permeability, ν the so-called hysteresis factor. If a sinusoidal field is imposed on the windings by means of sinusoidal currents, a magnetic flux with harmonics is created. Since the voltage is proportional to the differential quotient of the flux, the voltage also contains harmonics, proportionally 2 · νξ> _± , where Jg _{1 is} the maximum value of the sine field.

The frequencies of these harmonics can be very damaging under certain circumstances, e.g. B. when using the coils in the underlay telegraph, they easily fall into the area the speech frequencies and thus reach the speech apparatus, where they facilitate communication affect unfavorably.

It would be possible to leave the iron off and make air coils; thereby becomes however, the ohmic resistance of the coils as a result of the increase necessary as a result the number of turns is very high, so that this means cannot be considered for most purposes comes.

Furthermore, one could increase the iron volume so much that one would have the necessary self-induction achieved with a lower number of turns and then with a lower field strength $. However, with the usual sheet metal cores, this leads to unbearably large dimensions.

To increase the profitability of such iron coils is possible that one changed the core material for the present special conditions. So can a high harmonic freedom of the iron cores can be achieved without uneconomical dimensions to meet by one

power, ν and μ ₀ are material constants that are measured in homogeneous material (Jordan, ferromagnetic constants

*) The patentsitcher has given as the inventor:

August tip in Berlin-Siemensstadt.

for · weak alternating fields, electrical communications engineering from 1924, p. 7). Is this If material is not homogeneously or irregularly distributed (e.g. in the case of mass cores), this is how you measure effective average values, which may depend on the material constants themselves differ. In the above equation are

. based on these effective values.

Coils, soft a steel wire core or have a mass core, such values have already become known. A practical

v ² tical way, the factor —— the effective

To reduce the ν and μ ₀ values of a core, the core is provided with an air gap.

It has also become known to provide coil cores with air slots, around the flutter phenomenon in the transmission system in which these coils are used for loading to belittle.

The invention is based on the idea that it is economically correct not to take the measure for the elimination of harmonics in the same way for all coils of the switch for the underlay telegraphy, and therefore proposes that in arrangements for underlay telegraphy with electrical sieve chains that have iron cores whose effective values for the hysteresis factor ν and the permeability μ _{0 of} the iron core satisfy the condition

<5. ίο

- 6

to provide the cores with air gaps, the width of which is at the junction of the telephone branch the closest coils is larger than the more distant ones.

«2

In what way the relationship - = - through

μί

Choice of the width of the air slots can be influenced, results from the following considerations:

If ν and μ ₀ denote the values of the hysteresis factor or the initial permeability of an iron core, v ' or μ' _{ο denote} the corresponding effective values of the same TC core, but provided with an air gap, then

Po

- and v '=

4 »

where φ = 2 · -s- (d = width of the air gap, 22 = iron path in the circumference of the core).

It is then

and since fi · - ^ - > ο, this value is smaller

, v ² -

as -j-.

About the unnecessarily wide air gaps, the consequence of which is the necessary increase in the number of turns and thus the occurrence of copper losses would be avoided, each of the cores of the sieve chain is just so made far harmonic free, d. H. provided with as large an air gap as this is just necessary for him according to his situation.

The invention is explained in more detail by the drawing. Drawing ¹ contains, as an example, a schematic representation of a station for subordinate telegraphy: it denotes t the telegraph apparatus, / the telephone set, j a coil chain, k a condenser chain and Z the common transmission line, the coil chain s is provided with cores which have air gaps. The necessity of eliminating harmonics is less great in the coil pair aa than in bb and even less than in cc, because the harmonics generated in bb and aa are throttled again by the subsequent coil elements. The measures for eliminating harmonics are now graded in their degree such that the width of the air gaps decreases in the direction from cc to aa. With the width of the air gap, the volume of the cores can also decrease at the same time or the material needs to be selected less carefully.

_

Claims (1)

Claim: Arrangement for subordinate telegraphy with electrical sieve chains that have iron cores whose effective values for the hysteresis factor V and the initial permeability μ _{0 of} the iron core _{satisfy the condition - τ} <Ζ5 το- ~ ^β , characterized in that the cores are provided with air gaps and that the width of the core column in the coils closest to the branch of the telephone branch is greater than in the more distant coils. 1 sheet of drawings