Improvements in Telephone Installations.
Year: 1898

page_text: Date of Application, 13th Sept., 1898-Accepted, 15th Oct., 1898
. COMPLETE SPECIFICATION.
Improvements in Telephone Installations.
We, FRANZ OPRENDEK, of III Erdbergerstrasse; No. 14, Vienna, Austria,
Engineer, FRIEDRICH KOLISCHER, of I Braunerstrasse, No. 7, Vienna, Austria,
Advocate, and ALFRED LANDMANN, of No. 7, Rosenaustrassé, Nuremburg, Germany,
Engineer, do hereby declare tlie nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
This invention relates to improvements in telephone installations by which it is
possible to transmit the sound over any desired distance and at the same tiine to
so strengthen the tone and maintain the timbre that the reproduction of a speech,
of music or of a song in its real quality of sound may be with certainty audible
even at some distance froni the receiving instrument without the hearer being
obliged to hold the telephone receiver to his ear.
The effect of these improvements 18 that a telephoned message may be heard by
many persons at different points of the receiving. station as though the source of
the sound were actually at that place. Furthermore, it is possible to transmit
speech through a subinarine cable, a result hitherto impossible.
The means adopted by this invention for obtaining the desired result differ from
those suggested by others for the same purpose and proved to be impracticable, in
the manner in which the ring-inductors included in the telephone leads or the sub-
marine cable are wound and in the arrangement of such inductors; a multipli-
cation of the effective force is thus obtained without increasing appreciably the
resistance.
The characteristic feature of the winding of the inductors is that there are several
primary coils and only a single secondary coil common to all these primary coils.
The primary winding is all in the same direction on the core the wires being
wound on consecutive parts of the length of the core alternately in different layers.
In this way the magnetic impulse is enhanced and the induction effect of the
primary coils on each other is called into play and is strengthened in every layer
of the winding and in every turn of the layer so that there is a concentration of
the, induction effect in one and the same inductor, whereby a correspondingly
increased action on the microphone or microphones of the installation is produced.
The arrangement of the inductors is chiefly characterised by the fact that each
primary winding of the ring inductor forms a closed circuit in which are included
the microphone and a number of elements or batteries, whereby it is possible to
use the energy of the separate batteries to increase the microphonic effect. By
arranging, these closed circuits of inductors, batteries and microphones after the
manner of the relays in telegraph installations there may be effected a further
strengthening of the transmission of sound for any desired number of receiving
stations situated on the secondary circuit or on branches thereof.
For circuits of higher capacity than that of ordinary telephone circuits, such
as submarine cables, the arrangement is so far varied that a second magnetic

page_text: inductor together with a battery is included in the secondary wire of the first
inductor being the primary winding of the second. In this way the resistance of
the cable which is connected with the secondary winding of the second inductor,
is counteracted and the enhanced impulse is transmitted through the cable, bringing
about an increased sound effect at the receiving station by transposition in a
similarly arranged induction apparatus.
The accompanying drawings show several modifications of the improved con-
struction, suitable for different purposes.
Fig. 1 shows a diagrammatic view of a uniform double magnetic inductor con-
structed in the known manner from many sheet iron strips insulated from each
other by tissue paper.
Fig. 2 shows a ring inductor, the manner in which it is wound and its con-
nections with a microphone.
Fig. 3 shows the same arranged with two microphones and with the circuit of
telephone receivers.
Fig. 4 shows a form of the inductor suitable for a central telephone exchange.
Figure 5 shows a construction for widely audible effect together with an arrange-
ment for leads of high capacity (submarine cables).
Fig. 6 shows a double telephone installation with an arrangement whereby the
delivery of the telephonic message at the receiving station may be loud or soft as
may be required, so that several persons or only one may hear the message.
Fig. 7 shows the arrangement of a central exchange connected for example with
six groups of subscribers.
Fig. 8 shows two stations in connection with a submarine cable.
The unipolar magnetic inductor shown in Fig. 1 has two primary windings P¹³
and over these a secondary winding S.
The primary winding P is wound on the insulated core, ring R¹, in eight layers,
while the winding 12 is similarly wound on the ring R2, both wires being wound
in the same direction so that the current in P¹ or P2 is in the saine direction around
the core.
The secondary wire is wound in the same direction as the primary wires. One
end of the primary winding P' is connected with the positive pole of a battery B
and the other end with the microphone M of which the second contact is connected
with the negative pole of a second battery B. The positive pole of this battery is
connected with the primary winding P2 the other end of which is connected with
the negative pole of the battery belonging to the primary winding P¹.
By this mode of winding and connection, double magnetic impulses are produced,
and in consequence hereof a greater number of elements can be included in the
circuit, without causing the disturbances and variations in the reproduction of the
sound and damage to the microphones that otherwise necessarily occur.
The unipolar inductor shewn at Figure 2 has two primary circuits that are
wound as follows;--
The primary winding P1 is wound upon the insulated ring R as first layer, but
only round one quarter of the ring and on the same quarter is then wound 12.
In the second quarter of the ring on the other hand P2 forms the first and P¹ the
second layer; in the other two quarters the above changes are alternately repeated.
The core thus wound with several layers can be divided into any desired number
of sections, in each successive section of which the wire that in the primary section
formed the first layer forms the second layer, and vice versa.
Both primary wires are wound in the same direction, and upon the primary
winding thus produced is now wound the secondary winding S in the same
direction.
In the primary circuits P1 P2 are included, as in Figure 1, the batteries B and
the microphone M, while in the secondary circuit is included the receiver.
By this method of winding and connection, on the one hand the magnetic
impulses, and on the other hand the inductive action of the batteries included in
the primary windings is potentially increased.

page_text: A further strengthening of the reproduced sounds can be effected, as shewn in
Figure 3, by the introduction of a microphone in each primary circuit P¹ and Pa
in which arrangement the two primary wires can also be simultaneously coiled
round the core, the speaking being effected between the two microphones.
This figure also shews the connection of the receivers H and the respective cut-
outs A.
With the arrangement of the inductor shewn at Figure 4, three primary wires P¹
P3 P3 are wound upon the core R, which is of star shape, for easy winding, this
being effected as follows. 1' is wound as first layer upon the core part 1 and 2, as
second layer upon the core parts 3 and 4 as third layer on the part 5 and 6; 12 is
wound as first layer on 3 and 4, as second layer on 5 and 6 and as third layer on 7
and 8; P³ as first layer on 5 and 6, as second layer on 7 and 8 and as third layer
on 1 and 2.
The wires are wound in this manner several times round the core, and are led
so far that " issues on the part 1 of the core, P² on the part 3, and 13 on the
part 5. From the part 7 of the core the secondary winding is then-wound round
all the primary windings.
Figure 5 shews an arrangement with two unipolar magnet inductors for circuits
of high capacity such as submarine cables. In this arrangement either an
inductor according to Figure 1 is combined with an inductor according to Figure 2,
or two inductors according to Figure 1 are combined.
In the primary circuits P1 P2 of the inductor parts R¹ R2 are included batteries
and microphones similarly to Figure 3. The secondary wire S led away from the
part R of the core forms the one primary winding for the second inductor R, passes
thence to the positive pole of a battery B whose negative pole is connected to the
second primary winding of the inductor R, which winding is formed by the
secondary winding passing from the second part 2 of the core of the first inductor.
To the secondary winding S of the second inductor R is connected the line wire
or cable leading to the receiver.
This arrangement has the result that by the inclusion of the battery and of the
second inductor the induction impulses are potentially raised and passed through
the cable whereby, in consequence of such strengthening, the resistance of the cable
is overcome.
The diagram at Figure 6 shews the arrangement of the sending and receiving
stations according to Figure 3 for the communication between two subscribers.
The line wire L to which the apparatus are connected can be an ordinary
telephone or telegraph line, and is connected by means of a switch A as may be
required, either with an ordinary receiver G to be applied to the ear, or with the
loud sounding trumpet instrument H. For this purpose the ends of the secondary
winding S are respectively connected to the switch lever and with earth, and to
the switch is connected the trumpet instrument H. Round the secondary wind-
ing S of the inductor is wound a second secondary wire S¹ with few turns, which
contains the ordinary receiver G, and produces a weaker induction.
The diagram at Figure 7 shews a central exchange in which the main inductor R
has two primary circuits P1 P2 each of which contains a microphone M and a
battery B, and a secondary circuit S in which the call telephones H¹ are connected
in series, and with which the microphones M of the line inductors R³ are con-
nected.
These microphones which thus serve as the call instruments for the line wires L'
containing the separate subscriber groups, are contained, together with the batteries
in the primary circuits P1 P2 of the respective line inductors, the secondary circuit
of which is connected to the line wires L' from which the several branch lines for
the receivers H are led.
For further strengthening the action, receivers H² can with advantage be con-
nected to the lines L¹ at the exchange station, which also serve as call instruments
and which are fixed together with the microphones M2 of inductors R, and included
together with the batteries in the primary circuit of these inductors; while the

page_text: secondary circuit of the latter is connected with the line wire L'. The last named
arrangement has the same object as the relays of telegraphic apparatus.
Figure 8 shews the connection of two apparatus of the kind described with
reference to Figure 5 with a submarine cable.
Rand (RR) are the two inductors provided at each station, H are the receivers
which are included in the cable L and in the secondary circuit of the second
inductor R of each station.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. An arrangement of telephone installations for increasing the sound without
alteration of the timbre and without increasing the resistance, consisting of a closed
magnet inductor R with several primary windings P1 P2 and a secondary winding S
common to both, such, that the primary windings are wound on successive sections
of the inductor core as layers changing in their order these as also the secondary
winding applied over them being wound in the same direction, and the micro-
phones M and batteries B being included in the primary circuit while the
receivers H are connected to the secondary circuits, substantially as described with
reference to the drawings.
2. An arrangement of the inductor referred to in the first claim, in which a
star-shaped core R is wound with the primary circuits P1 P2 &c. in such manner,
that in two successive sections of the core the arrangement of the winding layers
is the same, but with each second pair of sections the arrangement changes so that
each of the primary wires serves as primary conductor for a certain portion of the
core, but serves for each of the other parts as secondary conductor in respect of
one of the other primary wires, all such primary and secondary conductors being
surrounded by the secondary winding substantially as described with reference
to Figure 4 of the drawings.
3. An arrangement of the inductor referred to in the first claim in which the
core consisting of the combination of several cores R¹ R2 &c., is wound with the
primary windings P1 P2 &c. in such manner that one of these wires is wound on
each ring core, while the secondary winding S is wound on all the primary wind-
ings, and is connected to the receivers, together with an inductor R and battery B
when required, substantially as described.
4. The combination of the inductors R and (R1 R2) referred to in the first and
third claims with a line wire or submarine cable of high capacity in such manner
that the secondary winding S of the cores R1 and R2 constitutes the primary wind-
ing of the second inductor R, and have a battery included between them while the
secondary winding $1 of the inductor R is connected to the cable with inclusion
of a receiver H substantially as described with reference to Figures 5 and 8 of the
drawings.
5. The combination of two of the arrangements referred to in the first claim by
means of a telegraph or telephone line wire to form a double station, the magnet.
inductors R of which are provided with two secondary windings S and S₁ having.
different numbers of turns, the winding having most turns being connected to the
loud speaking trumpet receiver H, while the other winding is connected to an
ordinary receiver G substantially as described with reference to Figure 6 of the
drawings.
6. An arrangement of the apparatus referred to in the first claim for enabling
it to be used at the exchange stations, wherein the magnet inductor R is connected
with a row of call telephones H¹ connected in series, and having microphones M¹
fixed thereto, and which are connected, together with a battery, to the correspond-
ing primary winding of line inductors R³ whose secondary windings constitute
line wires L' for receivers H connected groupwise thereto; there being included
in each of these wires L' a call telephone H2 whose microphone M together with

page_text: a battery, is connected to the primary winding of a magnet inductor R* connected
by its secondary winding with the said circuit L', substantially as described with
reference to Figure 7 of the drawings.
10
1000
ABEL & IMRAY,
Agents for the Applicant.