IMPROVEMENTS IN ELECTRIC TELEGRAPH APPARATUS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Leon Alexandre Brasseur and Stanislas
William Meldon de Sussex at the Office of the Commissioners of Patents on the
15th September 1877.
LEON ALEXANDRE BRASSEUR, of 20, Rue Fonsny St. Gilles, lez Bruxelles, and
STANISLAS WILLIAM MELDON DE SUSSEX, of 157, Rue du Progres, Bruxelles, both at
present residing at the Grosvenor Hotel, Buckingham Palace Road, in the County of
Middlesex. "IMPROVEMENTS IN ELECTRIC TELEGRAPH APPARATUS."
This Invention has for its object improvements in electric telegraph apparatus,
and the improvements relate more especially to the well-known Morse receiving
apparatus.
In the ordinary Morse apparatus the point or blade by which marks are produced
upon a travelling strip of paper is carried by a lever, which has also upon it the
armature of an electro-magnet, the wire coils of which magnet are coupled up to the
line wire. The armature is ordinarily held away from the magnet by a light spring,
but when a current from the line wire passes through the coils of the magnet the
armature is drawn towards the magnet, and the printing point or blade is brought
against the travelling paper.
In place of drawing the armature away from the poles of the electro-magnet by a
light spring we place on the opposite side of the armature and near to it the ends of
two soft iron cores similar to the cores of the electro-magnet. The opposite ends
of these cores we couple together by a permanent horse-shoe magnet. This magnet
acting through the soft iron cores attracts the armature and holds it away from the
electro-magnet. The soft iron cores are surrounded by fine wire coils similar to the
coils of the electro-magnet, and the currents from the line wire are caused to pass
through all the coils.
When a current passes from the line wire through the wire coils, the electro-magnet
attracts the armature, whilst the poles of the permanent magnet are reversed and
repel the armature, which is feebly magnetized from its proximity to the poles of
the permanent magnet; for short lines the armature may itself be a weak
permanent magnet. The wire composing the several coils is arranged to offer the
same resistance as the resistance of the line wire.

page_text: The Drawing annexed shews part of an electric telegraph receiving instrument
with our improvements applied to it.
A is a permanent magnet, the power of which can be increased or diminished by
sliding across it the soft iron regulator R.
B and B¹, bobbins carrying fine wire coils, the wire being of a section calculated to
give the same resistance as the resistance of the line wire.
In the apparatus shewn the section is calculated to give a resistance of 4,500
kilometers, that is to say, that the bobbins carry a thread of 4,500 of resistance,
which is equal to the resistance of the Atlantic cable for which the apparatus is
designed.
It is known that it is not practicable to use bobbins larger than a certain diameter,
as magnetization is no longer or but feebly produced when this limit has been passed.
It is therefore necessary to obtain the requisite small diameter of bobbin by
employing extremely fine wire.
G, cross bar of copper for supporting the cores of the two upper bobbins, and also
by means of a piece projecting from it for supporting the permanent magnet A.
T, bar of soft iron connecting the two cores of the lower bobbins.
P, soft iron armature for actuating the pointing blade of the Morse apparatus.
Note. If the line resistance is small, this armature in place of being of soft iron
might be a steel magnet.
a, south pole of the magnet A.
b, north pole of the magnet A.
a¹, south pole of the cores of the lower bobbins at the time when a current
passes.
b¹, north pole of the cores of the lower bobbins when a current passes.
M, a portion of the ordinary Morse apparatus.
The current from O through the several wire coils to S magnetises a¹ and b';
a', south; b', north. At the same time the poles a, b, of the permanent magnet are
reversed, a becoming north and b south.
The armature P which always retains a portion, almost infinitesimal, of residual
magnetism, remains north at the end b and south at the end a, is repelled by a and
b of the upper bobbins; a having been changed to b and b to a; simultaneously it is
attracted by a and b' of the lower bobbins, a¹ and b¹ then becoming magnets inverse
to the magetism remaining in the armature. The same effects are produced at each
passage of the current, and consequently the apparatus works easily with almost an
inappreciable quantity of electricity.
We would observe that one of the results obtained from the above construction is,
that the return currents are prevented from giving any false signals.
In fact the
passage of a reverse current, the stronger it is, the more it restores the normal action
of the permanent magnet, its poles being then no longer reversed.