IMPROVEMENTS IN APPARATUS FOR INTEN- SIFYING ELECTRICAL CURRENTS
Year: 1885

page_text: I FFLIX PAUL ERNEST DE LALANDE Civil Engineer and Electricien of 34 Rue
de la Montagne-Sainte-Geneviève, Paris, in the Republic of France do hereby
declare the nature of my invention for IMPROVEMENTS IN APPARATUS FOR INTEN-
SIFYING ELECTRICAL CURRENTS and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement
The object of the present invention is the construction of a system of apparatuses
by means of which currents of small electro-motive force generated by any given
source of electricity such as a battery composed of a few cells only are transformed
into currents of a high electromotive force having this particularity that the high
tension currents so obtained are possessed of the property of operating through
great resistances not only on polarized receivers (that is to say receivers in which
there are permanent magnets) but also on ordinary receivers, electro-magnets
relays, electric bells etc I give this system the name of "Intensifying Trans-
formator"
The above mentioned particular property distinctly establishes the difference
which exists between my "Intensifying Transformator" and the ordinary induction
coils the latter certainly producing induced currents of high tension but incapable
of operating on ordinary receivers, and operating in an only feeble manner on
polarized receivers.
This difference in the mode of action is caused by the extreme shortness in
duration of ordinary induced currents whereas the currents produced by my
"Intensifying Transformator' are of a very marked duration which is an indis-
pensible condition for producing the magnetization of soft iron cores
"
In fact the
currents of my transformators act in the manner of a continuous current of a very
sensible duration
The intensifying transformator is composed of a core of iron on which two
insulated wires are wound One of these wires, the primary, 18 of a comparatively
great thickness and the battery current flows through it, the other wire, the
secondary, is generally very fine and very long and the high tension transformed
currents which are developed in it by the makes and breakes of the primary
circuit flow through it. The general arrangement of the intensifying transformator
18 analogous to that of ordinary induction coils but the following-particularities
establish an essential difference between them
I The core of the coil 18 constructed in such a manner that the magnetization
which is imparted to it by the primary current requires an appreciable length of

page_text: time before it becomes exhausted after the said primary current has been
interrupted this result, the contrary of that which is desired in ordinary induction
coils is obtained ⚫
"
(a), by giving the core a comparatively large mass
(b)-by making the core of one piece only or of a very small number of pieces
of iron, cast iron, or nontempered steel, instead of making it of a bundle of soft
iron wires.
(o) by giving the core one of the shapes shown in the annexed illustrations
Fig 1. The elongated cylindrical shape E F much longer than the col
itself A B C D
Fig 1. 1. The shape of a cylindrical core G H terminated by thick iron plates I J
constituting the flanges of the coil, or more generally by armatures or prolongations
varying in their disposition such as represented in Fig 2* and 2b
Symmetry is found an advantageous disposition.
Fig 3-and 3 The horse shoe shape K L M the induction coil being preferably
and for reasons of symmetry composed of two half coils NP the primary and
secondary wires of which are suitably connected. (The coils can be placed at a
smaller or a greater distance from the extremities of the core)
Fig 4 A shape derived from the preceeding one and made of two cylindrical
cores QR, ST, fixed to one solid piece UV of a certain thickness -In all these
various arrangements, the cores may be internally hollowed out more or less thus
taking the shape of tubes
II The useful effect of the intensifying transformator can also be obtained by
dealing with its various parts in manners different to those which are applied to
ordinary induction coils, for instance
(d) By making the primary wire of a comparatively great length so that a strong
magnetization which will only slowly disappear is obtained in the iron core through
the action of the battery of which the constants are approximately known
(e) By adopting dispositions which do not allow of any abrupt interruption of
the current such as interrupting the current by means of an india rubber tube
filled with mercury which closes the circuit, or by means of carbon contacts Or
the primary circuit may not be completely opened, its resistance being made to vary
rapidly
f-By suppressing the usual condensor which is used in connection with
induction coils.
Modus operandi of the Intensifying Transformator. It must be understood that
the intensifying transformator may be used in connection with a current of any
intensity and produced by any source whatever such as from a battery, a dynamo
or magneto electric machine etc
If in order to fix the ideas we suppose that the primary current is generated by
a battery composed of two or three oxide of copper or of the same number of
Leclanche's oella, the transformator suitable for that case, for example of the type
illustrated in Fig I will have a cylindrical iron core of 12 to 15 millimetres
diameter size and of from 150 to 200 millimetres long
The primary wire will have a thickness of 06 millimetre diameter six turns of it
being wound over each other on a length of about 80 to 100 millimetres.--The
secondary wire will have a thickness of 015 to 02 millimetre diameter and be of a
resistance of 200 to 250 ohms or more The battery current is closed on the
primary wire by means of a push or of any other convenient manipulator, an
ordinary electric bell push giving results quite satisfactory The secondary wire 18
connected with the line at the extremity of which are the receiving apparatuses
An earth may be used as a return wire It is known that when a primary circuit
18 first opened and then closed, two currents of contrary directions are induced in
the secondary circuit, one at the making, the other at the breaking of the primary
circuit,
The breaking induced current is of a much higher tension than the making one,
so much so that should the resistance of the line and of the receiving apparatus be

page_text: at all considerable the making current has no appreciable effect on the receiving,
apparatus. In this case, things take place exactly as if the breaking current alone
was acting.
Therefore each time a make or a break occurs in the primary circuit, a
transformed current will be sent through the line and will operate on the receiving
apparatus such as an annunciator, a relay, or an electrio bell etc The direction of
the transformed current varies according to that of the primary circuit in the
intensifying transformator It will therefore be possible by the use of suitable
commutators or manipulators, to at will send in the line currents said positive or
negative, capable of differently operating on a polarized relay
The intensifying transformator of which the dimensions have been given here-
above can usefully operate on a suitable receiver such, for instance, as an ordinary
electro magnet the two coils of which have a total resistance of from 200 to
500 ohms and this through a resistance of a few thousand ohms
These results are susceptible of an immediate application on telephonic lines
Each subscriber's station is generally provided with two batteries one being used
in connection with the microphone and the other with the call bell or signal It is
very easy to suppress the latter battery and this can be effected by the addition
of an intensifying transformator such as we have described to the said telephonic
post or station
The call push at the subscriber's station is arranged in such a manner that when
not acting (the telephone being hanging on the commutator) the line communicates
with the bell S by means of the bridge A (Fig 5) and of the spring B C which
carries the call push D
When the call push D is pressed, the communication between the line and the
bell S is interrupted, the secondary wire of the transformator T 18 thrown into
the line circuit owing to the spring B C coming into contact with the spring E F,
the other end of the secondary wire being connected to earth or to a return wire,
the spring BC thereafter comes into contact with G causing the primary wire to
be thrown into the closed circuit of the microphone battery P
If the call push D is now depressed, the spring B C leaving firstly the contact G,
the battery current in the primary wire of the intensifying transformator 18
interrupted and this break is the cause of a transformed current being developed
in the secondary wire, this transformed current flows through the line to the
exchange where it actuates the receiving apparatus, generally an annunciator or
a bell's relay Nothing moreover is changed in the other arrangements of the
telephonic station
A series of makes and breaks made at spaced intervals in the primary circuit of
the intensifying transformator will cause a series of transformed currents to act
directly on the bell, polarized or not, placed at the other end of the line
In this case the usual make and break spring of the electric bell is not required
as the coils close, in a continuous manner, the circuit of the line
In order to simplify the operation of producing the series of interrupted curients
a vibrator, similar to that of an electric bell may be placed in front of the core of
the transformator, in the primary circuit
If in this condition the primary circuit is and remains closed, the vibrator
produces the makes and breaks of the primary current and the transformed currents
act on the electric bell placed at the receiving station, in the secondary circuit of
the intensifying transformator
The various arrangements and shapes of cores which I have described and
illustrated can also be applied with advantages to the construction of intensifying
transformators with a single wie for the utilization of the extra-current
Having now described and illustrated my invention and the manner in which the
same is to performed I claim as my invention
1° The construction of apparatuses for the production of induced or transformed
currents of comparatively long duration and capable of effectively acting on
ordinary electro magnets (results which cannot be obtained with ordinary induction

page_text: coils) as described and illustrated, and the details of which are characterized more
particularly by
a the use of iron cores of large masses, having more particularly the shapes
illustrated in Fig 1 to Fig 4, and generally projecting of a great distance outside
the limits of the interior of the coils.
b The described means of retarding or otherwise rendering progressive the break
of the induced or transformed current, such as increasing the length of the primary
wire, suppressing the condensers and using contacts, the conductivity of which is
variable
2° The construction of single wire apparatuses for the utilization of the extra-
currents, the said apparatuses being provided with the particular arrangements
described and illustrated in the specification and giving the results indicated in
claim 1