with Electric Signalling Apparatus or Measuring Instruments.
Year: 1887

page_text: with Electric Signalling Apparatus or Measuring Instruments.
I JOHN EDWARD WATSON, residing at Louisville, in the County of Jefferson and
State of Kentucky, one of the United States of America, Electrician, do hereby declare
the 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 has relation to improvements upon present methods and means of
signaling by electricity and it is designed to involve not only systems in which the
received signals are apparent to the eye or perceptible to touch but also those in which
the signals are appreciable mainly by the sound emitted from the receiver, whether any
And while the more important
graphic record of the sound vibration be kept or not.
purposes of the invention refer to facilities of electrical communication over lines of
great length and resistance it will be found to offer material advantages when applied
to short lines or circuits.
The invention is designed to be readily applicable to all systems of signaling in use,
whether the Morse system, the printing method, the chemical recording or the auto-
graphic be employed. Or whether it be preferred to use the telephonic or resonator
system.
It will be found serviceable in systems of automatic electric signaling and in fire
aların circuits, in railway signaling and in the distribution of time signals over lines of
great length, and wherever it may be necessary or serviceable to operate with weak or
feeble currents its advantages will be apparent.
The invention involves the method of using two voltaic currents in opposition to
vary the magnetic attraction and means or apparatus whereby the method may be put
in practical operation in effecting telegraphic or telephonic communication or in other
forms of electric signaling.
It is well known that the magnetism or magnetic force while strong near the pole or
poles of a magnet or electro-magnet is, at a distance from such pole or poles very
feeble or weak, and the object of this invention is to utilize this feeble or weak
influence which is far less variable between two points at a certain distance from each
other in its direction of action than is the strong force near the pole between two
points, situated the same distance apart or even nearer to each other. This distant

page_text: magnetic influence I shall call for the purposes of this description, the poising force,
and its scope or the limit within which it can be made available, the poising field.
This field is designed to be practically outside the limit of residual magnetism. The
method which I have invented contemplates passing the main current and a constant
local current in opposite directions through separate insulated helices of an electro-
magnet, and in actuating the armature, diaphragm or other sub-magnet at such a
distance from the pole or poles of said electro magnet that it is subject to the weaker
but more constant magnetic influence and is practically outside of the field of residual
magnetism.
The means of apparatus involved may be of varied design and may refer in features
of construction to especial lines of application for which they are intended. For the
most part they may be of simple character and, exclusive, of those features which are
in common use refer more particularly to the relay or receiver and its connections.
The main advantages of the apparatus are discerned in its capability of operating with
exceedingly feeble currents and in its freedom from contra-inductive effects. And
while the receiving relay is designed to be extremely sensitive, the power and speed
with which it can be operated are sufficient for the work. Its main peculiarities refer
to the employment of two voltaic currents in opposition and the arrangement of the
armature or sub-magnet at a distance from the pole or poles.
In the accompanying drawings some forms of suitable apparatus are illustrated and
it is premised that variations in the constructions shown may be made without
departing from the principles involved.
To facilitate reference similar letters are used in the different figures of the drawings
to indicate like parts.
Fig. 1 is a diagram or graphic illustration of apparatus involved when a separate
sounder or receiver separate from the relay is employed.
Fig. 2 is a diagram illustrating the method or process wherein both the near and
distant stations are represented.
Fig. 3 is a plan view of a relay employed in this method wherein the armature is
made adjustable modes of adjusting the tension by either a spring or a weight being
also shown.
Fig. 4 is a longitudinal section of the relay.
Fig. 5 is a plan view of a relay apparatus showing sounder and key. In this figure
the relay magnet is represented as adjustable.
Fig. 6 is a side view of a telegraphic sounder which may be employed in connection
with the relay. Its construction is similar to that of ordinary sounders.
Fig. 7 is an enlarged view of a key which does not differ materially in construction
from ordinary telegraphic keys.
Fig. 8 is an end view of a relay instrument showing permanent magnet M in
connection with the poles of the electro-magnet.
Fig. 9 is a side view of this relay.
Fig. 10 is a diagram or graphic illustration illustrating the bipolar arrangement of
helices and circuit wires.
Fig. 11 is a sectional view of a telephonic receiver showing adjustable relay magnet
and circuits.
In Figs. 10 and 11 the transmitter is indicated at C.
Fig. 12 is an exterior plan view of this telephonic receiver showing its elliptical
form and the focal arrangement of the auricular opening.
Figure 13 is a sectional view of a different form of telephonic receiver wherein the
heads of the spool are arranged to serve as the poles.
Fig. 14 is a plan view showing the relay magnet of this receiver in its case.
Fig. 15 is a plan view of a galvanometer adapted to be operated under the principle
of this invention.
Fig. 16 is a longitudinal sectional view of the same.
Fig. 17 is a diagram showing the circuit wires and the case heads of the relay
openings being shown in the latter for the passage of the wires.
Figure 18 is a detail view showing the graduated face of the adjusting nut A.

page_text: of this invention.
Fig. 20 is a similar graphic representation of the duplex arrangement showing the
armatures and sounders in circuit therewith.
Apparatus adapted to facilitate electrical communication over conductors as in land
and marine telegraphy may be readily illustrated.
To this end I employ in addition to the main line or conductor, its battery, and key
or transmitter, a relay having a local closed circuit, and a sounder, indicator or
recorder.
Or, the relay may itself serve as indicator recorder or receiving instrument for it is
designed in the utilization of the features of this invention to effect among other objects,
simplification of apparatus.
In the diagram Fig. 1 of the drawings, the letter L, designates the main line or
conductor and B the inain line battery, C is the key or transmitter and D the relay
having the electro-magnet E and sub-magnet or armaturo F, the latter being in or a
part of the circuit V of the sounder or indicator W. H is the local circuit of the
relay having its battery K, and the relay magnet E is wound not only in the local
circuit H, but also in the main line circuit it being however so arranged that the local
current runs in the opposite direction to that of the main line. With this object in
view the relay magnet may be directly wound in the local circuit and reversely wound
in the main, line. But it is preferred to wind the helices directly in both circuits and
to pass the currents therein in opposite directions.
In the magnet illustrated the helix of the main line is formed of many turns of fine
wire, as indicated at m, while the helix of the local circuit is formed of comparatively
few turns of coarse wire, or wire of comparatively low resistance as indicated at 1.
The electro-magnet may be unipolar but in the drawings I have preferred to illustrate
mainly the bipolar form. And the coarse wire is usually wound next the axis reel or
core and the fine wire over the coarse wire. But the arrangement may be reversed.
the coarse wire being wound to form the outer layer or layers.
In any event however, the coarse wire helix or helix of low resistance is in com-
munication with the poles of the local battery, and the fine wire or high resistance helix
is in connection with the main line. These helices are properly insulated from each
other by winding the wires with silk or other insulative in the customary manner.
F is the armature or sub-magnet of the relay and it may be pivoted, suspended or
otherwise supported to have a movement in front of the pole or poles of the electro-
magnet. It may be a metallic strip, plate, spring or diaphragm, or a lever as
illustrated. N is a rest stop, of rubber or duly insulated, and P is a contact the latter
being in the sounder or indicator circuit and so arranged that when contact is made
between the armature and the contact P, the sounder or indicator circuit is closed. In
some apparatus, and especially in telephonic receivers, wherein the armature is a
diaphragm as indicated in Fig. 10 of the drawings, the armature is itself the sounder
or indicator. S represents a spring weight or other tension of the armature. Its own
elasticity or weight will serve the purpose when properly applied in relation to the
magnet, the object being to oppose the magnetic attraction sufficiently to effect a
counterpoise or nearly so, in the distant or poising field of magnetism. In fact the
best way to adjust the armature is first to bring it to an equilibrium and then to adjust
the stops. In the case of a telephonic receiver the tension of the diaphragm is
sufficient and the adjustment may be made by removing the electro-magnet toward. or
away from it until the communicated sounds are emitted. When properly adjusted
the diaphragm will be sufficiently distant from the magnetic poles to avoid casual
inductive vibration.
Usually I prefer to make the contact and rest stops adjustable, suitable screws as
indicated at I and J being used. And the electro-magnet may be made adjustable by
the employment of a screw V and nut e as indicated in Fig. 4. Or the armature may
be made adjustable by means of a similar screw V or otherwise. Or an adjustable
resistance may be employed in the low resistance circuit. In the case of the telephonic

page_text: receiver I have illustrated in Fig. 10 the electro-magnet as mounted upon a slide in
the handle said slide being adjustable by means of a screw.
The mode of operation is as follows:-
The low resistance or local circuit being always closed, the current thereof acting
through the low resistance helix of the relay upon its armature which is located not so
near the magnetic poles as to be within the limit of the strong and quickly varying
power, but at a marked distance therefrom within the poising field of magnetism
serves to counter balance or poise the armature or to hold the same in position of
equilibrium.
In the diagram a counter balance spring or tension is indicated at S but as I have
heretofore explained, this purpose may be served by the gravity of the armature itself
or its inherent elasticity." The poising distance will vary with the size of the wire
forming the low resistance coils of the magnet and the strength of the local current
constantly passing in the closed circuit and may extend to one-eighth of an inch of the
magnetic pole and even closer. Or it may be found at a considerable distance there-
from it being quite possible to work at a distance of an inch from the pole. The main
line being open the armature can readily be brought to the position of equilibrium
according to the construction of the relay instrument by adjusting the magnet or the
tension, or by introducing resistance in the local circuit or by adjusting the armature
itself.
The main circuit being closed the contact and rest stops when these are employed as
for instance in the relays which I design for telegraphic purposes, are adjusted in
proper position and the receiver is ready for communication. When the main line is
open and the low resistance circuit is in full power the armature will be in contact
with the rubber rest stop N this being the proper position of adjustment. But when
the main line current is operating in the fine wire or high resistance helix of the relay
its action is opposed to that of the coarse wire or low resistance helix of said relay, and
its effect is to neutralize to a certain extent the magnetizing influence of said low
resistance helix thereby weakening the attractive power of the electro magnet and
allowing the armature to move back to position of contact with the stop P closing the
sounder or indicator circuit as shown in the diagram Fig. 1.
In transmitting, the switch of the distant key or transmitter is opened, interrupting
the flow of the main line current in the high resistance helix and allowing the helix
of the low resistance circuit to regain at once its full magnetizing power whereby the
armature is drawn forward to its position of equilibrium or against the rest stop N.
When the key is closed to make a signal the main current passing in the fine wire
helix m at once acts to hamper the magnetizing power of the coarse wire helix and
thereby destroy the equilibrium of the armature and it is moved back by its weight or
tension S to contact position closing the local sounder or indicator circuit U. And
when the key is opened or rises to break circuit in the main line the full magnetism of
the electro magnet promptly asserts itself drawing the armature from the contact stop
and breaking the local sounder or indicator circuit. In the case of a relay which is
at the same time the receiver, the movements of the armature which is the sounder
or indicator are effected in a manner precisely similar. And when the receiver is
telephonic in character having a diaphragm or plate armature or sounder, and there
are no contact and rest stops, the state of counterpoise or equilibrium of the diaphragm
involves the opposition of its own tension on the one hand and of the distant or
poising magnetic force on the other.
For if the diaphragm be adjusted near the poles or within the strong and quickly
varying field of magnetism the hampering influence of the feeble current of the
main line upon the electro-magnet would be insufficient to appreciably lessen the
magnetic attraction thereon.
Usually in telephonic receivers I prefer to fix the diaphragm and adjust the magnet
or magnetic core. This may be readily done by securing the magnet core to a slide T
in the handle Y and employing a screw V for the adjustment as indicated in Fig. 10
When the magnet is properly adjusted the sounds due to the vibrations of the

page_text: transmitter are fully heard while the diaphragm is designed to be so removed from the
pole as to be out of reach of the effects of casual induction.
In winding the helices of the electro magnet much latitude is allowable. I have
obtained excellent results, when using for the high resistance helices some eight
thousand turns of No. 36 wire of the Birmingham wire gauge and for the low
resistance about two hundred and fifty turns of No. 26 wire, same gauge, or it may
be of such size that the resistance of the coils will equal the battery resistance. A
local battery of from one to two volts electro motive force will serve an excellent
purpose. If the battery is stronger in proportion the point of equilibrium of the
armature will be farther from the poles of the inagnet and the instrument will be more
delicate. Very little electro motive force is required to move the armature when
arranged at a distance from the poles in the manner hereinbefore described.
If the local battery is stronger the distance of the armature from the poles must be
increased to obtain equilibrium.
By this invention it is designed to avoid to a great extent if not completely the
effects of retarding and inductive troubles of the main line. Even should such be
present and of sufficient electro motive force to affect the fine wire helix there would
be no appreciable evil effect therefrom in the coarse wire helix which is the chief
magnetic element of the relay or receiver. And the armature is located in the poising
field of magnetism which is at such a distance from the poles of the magnet that the
effect of residual magnetism is reduced to a minimum and may be practically
disregarded. In all methods heretofore in use the armature has been worked in the
strong field of residual magnetism where all the evils of induction had full sway. The
current of the main line or circuit L is comparatively weak, being usually of such
character that when passing through its helix or helices m in the absence of the current of
the closed low resistance circuit it cannot so magnetize the core as to do any practical
work by the magnetism generated. But however feeble, it will yet have power to act
through its helix to affect the magnetizing action of the low resistance helix so
hampering this influence that the magnetism which would otherwise result from the
action of the current in the low resistance coils is of lower intensity when the main
circuit is closed. The action of the oppositely directed current in this circuit prevents
the current of the low resistance circuit from magnetizing the core to its maximum.
And yet while this effect is material and persistent it is found that the variation
from the maximum magnetic force of attraction which can thereby be effected is of
delicate character such in fact that if the armature or sub-magnet were placed in close
proximity to the poles no available results could be obtained. For when the armature
is located close to the poles it is within the powerful and quickly varying field of
magnetism and the delicate variation from the maximum intensity caused by passing
the weak current of the circuit L in the helix of this circuit cannot be practically
utilized.
The difference between the maximum and the minimum intensity is so slight in this
locality that mechanical skill would be at fault in the construction of a suitable
armature. But when the armature is located at a distance from the poles in the
weaker but more constant field of magnetism there found, the armature may be of
ordinary character and will readily respond to the variation in the intensity of the
magnetic force and if pivoted or supported under some tension whether by spring or
weight can be easily brought to an equilibrium. And I find that when the armature
is adjusted to or nearly to this position of counterpoise it is properly arranged to
respond to the variations in the magnetic intensity effected by the action of the
current in the high resistance coils.
When a separate sounder or receiver is employed as indicated Fig. 1 of. the
drawings it will be observed that the sounder or receiver circuit is opened on the
action of the main current and is closed on the breaks or cessations of such actions by
the attractive power of the magnet. Sometimes I may use a permanent magnet M
in this relay as shown in Figs. 8 and 9 employing its poles as the cores of the
helices and, when this is the case, the coarse wire is wound and the battery applied
to make the electro magnetic poles of like polarity to those of the permanent magnet.

page_text: The permanent magnet is not however regarded as an indispensable feature of the
relay. The weak main line current being usually of little quantity may not be
capable through its helix m of setting up sufficient magnetism to affect the armature
directly but it has, nevertheless an important and essential bearing in hampering the
action of the constant current in its helix l. For, when the main current is broken,
the local current alone acting produces a maximum magnetic force of attraction, but
when the main current is closed its operation in the helix m hampers or trammels the
electro-magnet so that its attractive force is reduced. So also if the strength of the
main current is lessened by increment of resistance at the transmitter or otherwise,
the magnetizing effect of the local helix and consequently the attractive power of the
electro-magnet is increased. It will therefore appear that in this method of operating
there is designed to be no break or cessation of magnetic influence upon the armature,
the local circuit being always closed. But there are successive increments and
diminutions of the magnetism which are available for the operation of the receiver.
The magnetic force is never absent even momentarily but is always present and acting
and when the transmitter is in operation the action is undulatory or by successive
diminutions and increments of the magnetism whatever be the character of the main
current. In fact by this process an intermittent current of the main line will be
converted by the receiving relay into continuous waves of magnetic force which may
be of regular undulatory character. The electric reproduction of sound waves is
designed to be accomplished by this process whether the sounds have complex
character as in the case of articulate speech or are of more simple nature. And it is
further designed to reproduce the sounds transmitted audibly with like qualities of
pitch and timbre but also approximately as loud or sonorous as the transmitting
sounds. In the drawings of the telephonic receiver Fig. 11 I have illustrated a
tripolar magnet but the magnet may be single and wound with single coarse and fine
wire helices and it may have iron spool heads which may be used as poles as
indicated in Fig. 11.
In the measurement of the strength of electric currents through their magnetic
influence this invention will be found valuable. Most sensitive galvanometers can be
constructed upon the principle involved. In the drawings Fig. 15 such a galvanometer
is illustrated, in which the letter D designates the electro-magnet or relay magnet
having the contra electric helices connected respectively in the main or trial and local
or constantly closed circuits and F a counterpoised armature in the distant or poising
field of magnetism. A is a nut having a fractional scale a and V₁ an indicator having
parts b and c.
R is a graduated scale on the core connection which is moved by turning the nut A.
The local and trial circuits being closed, the armature indicator is brought to a
counterpoise and the indicator to the zero points of the scales. If extra resistance is
introduced into the trial circuit the equilibrium of the armature will be destroyed.
Then the magnet is adjusted until the equipoise of the armature is restored. Now if
the scale R has been graduated to ohms and the scale a to fractions thereof the amount
of the introduced resistance can be determined by inspection.
In illustrating the application of this invention to duplex telegraphy reference is
made to Figs. 19 and 20 of the drawings in which the letter L, designates the main
line and B, B main line batteries of the near and distant stations. The fine wire
helices of the main line are indicated at m m and m³, m' and l, l, and 1, are the
coarse wire helices of the electro magnets E and E' of the local circuits H and H¹.
Local batteries are represented at K and K¹.
C, represent the keys at the two stations and Z Z' designate wirès, each
connecting its key to the wire between the main line helices of each station as indicated.
The armatures are represented at F F each being located in front of the poles of its
electro-magnet at a sufficient distance therefrom to be out of the strong field of
magnetism and within that which although weaker is more constant as hereinbefore
explained.
In the duplex form the operation is as follows: When the key C at the near station
is closed down the main current from battery B₁ passes through the helices m² m² and

page_text: through one helix m and key C to earth. In this manner, signal is made at the distant
station, the passage of the main line current through the helices m', m¹ being sufficient
to limit the inagnetizing action of the local circuit in its helices and release the
receiving armature to make signal or contact.
'
Action of the receiving armature at the transmitting station is prevented by the
current from the battery B of this station, which passing through the other high
resistance helix m neutralizes the effect of the current of battery B', passing through
its fellow. The electro magnet at the transmitting station therefore remains under the
full magnetizing influence of the local helices at the station and the armature is held
up. Similarly when the key (1, is closed down the armature at this station is
prevented from responding by the full action of the helices of the local circuit
and by the opposed influence of the currents from battery B and from battery B¹
in the respective helices m³ m¹ neutralizing each other. But the armature at the
other station responds because the current from battery B only is then passing
through its helices m m and limiting the magnetizing influence of the helices of
the local circuit at that station.
When the key is raised breaking circuit the current in the main line from battery B
ceases and the armature at the distant station being then under the full power of
its electro magnet is attracted breaking the contact or signal. Similar action takes
place on the rise of the key C₁ the armature at the other station being attracted.
When however both keys are closed down, the main line batteries B B¹, act locally
through the high resistance helices m m and m² m² respectively limiting the magne-
tizing influences of the helices of the local circuits and causing the receiving armatures
to fall of to make signal or contact. In using the Morse signals or dots and dashes it
is apparent that one key may remain closed longer than the other.
If both keys are
down, the key C, for instance to make a dot and the key to make a dash the action
will be as follows:-
The key will rise first. Then the current from battery B will influence the main
line and passing through one helix m' of the electro magnet E will neutralize the
action of the other, helix m' and the full power of this electro magnet will
at once attract the armature causing the contact or signal to cease at this station.
At the same time the key C¹ remaining closed to form a dash at the other station
the main line current passing through the helices m will limit the magnetism of the
electro magnet E so that its armature will not be attracted but will continue the signal
until the key Crises. For railway signaling the invention will be found to possess
superior advantages because it is designed that the apparatus involved shall not be
liable to serious disturbance on account of rain or dampness. In the practical opera-
tion of this method it will be apparent that it is intended to use currents of exceeding
weakness or of such low order that no casual conduction set up by atmospheric con-
ditions or otherwise can deflect them from their proper paths. In fact it is believed
that by this mode of telegraphy, railway rails, fence wires and other extending
metallic lines originally intended for other and different purposes can with some
modifications of connection be. utilised as conductors of the weak currents which I
employ for it should be borne in mind that the principle of this invention involves the
use of a weak current of electricity to oppose and limit the magnetizing influence of a
closed local circuit and thereby weaken the magnetism at a distance from the magnetic
pole in contradistinction to the employment of a strong current of electricity to
produce at a distance a magnet which will attract an armature when placed close to
the poles.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is a
1. The method and means of producing motion of the armature or receiver by
passing two voltaic currents in opposite directions to vary the magnetic attraction,
substantially as specified.
2. The method and means of operating the receiver of an electric current, by
locating the armature or sub magnet at a counterpoising distance froin the magnetic

page_text: poles and passing two voltaic currents in opposite directions through insulated helices
of the electro magnet to vary the magnetic attraction, substantially as specified.
3. In a system of electric telegraphy or signaling, the method or process of making
contact by mechanical appliance or tension exterior to the circuits and breaking the
same by means of a constant current of low resistance through a relay involving the
action of the main line current, substantially as specified.
4. A method or process of telegraphy or electric signaling which consists in, first
bringing to equilibrium, the armature of an electro-magnet involving a constant direct
low resistance current and a reversed main current and secondly; operating said
armature by said low resistance current for attraction, and for retraction by a tension
or mechanical appliance exterior to the circuits but conditioned upon the action of the
main line current, substantially as specified.
5. The method or process of telegraphy or electric signaling which consists in
operating an armature or sub-magnet, in equilibrio between a retracting spring or
tension and the counterpoising influence of an electro magnet in a closed low resistance
circuit by the action of the main line current passing reversely in a helix of high
resistance upon said electro magnet but insulated from its low resistance coils,
substantially as specified.
6. The method of electric signaling in which the receiver armature is vibrated by
the employment of the main line current in opposition to the constant current of a
closed local circuit of low resistance, substantially as specified.
7. The method of operating the main line current in helical opposition to a constant
local current in the relay magnet to weaken the magnetism and through the variation
of magnetism thus produced actuating an armature diaphragm or other magnetic
receiver located at a counter-poising distance from the poles of said relay magnet,
substantially as specified.
8. The combination with an electro magnet having a closed circuit of low resistance,
and high resistance coils in the main line of a movable armature under gravitation or
other tension counterbalancing the poising force of said electro magnet substantially
as specified.
9. An armature in a receiver circuit counter-poised against the magnetic attraction
of a relay helix in a closed circuit and operated by weakening the magnetism through
the action of the main current, substantially as specified.
10. The combination with the main and closed local circuits passing currents in
opposite directions, of a relay magnet having insulated helices respectively involving
said circuits and a counterbalanced armature in the receiver circuit, substantially as
specified.
11. The combination with the main and closed local circuits passing currents in
opposite directions of a relay magnet having insulated helices respectively involving
said circuits, a counterbalanced armature and means of adjustment, substantially as
specified.
12. The combination with a relay magnet directly involving a closed low resistance
circuit, and reversely involving the main circuit, of an armature counterbalanced
against the attractive influence of said electro magnet, substantially as specified.
13. The combination with a relay magnet involving insulated helices of a main
circuit, and of a constantly closed local circuit, of an armature counterpoised against
the attraction of said magnet by gravitation or other tension and oppositely applied
main and local batteries, substantially as specified.
14. An electro-magnet having two insulated helices involving oppositely directed
currents, respectively in low resistance and in high resistance circuits and the
respective batteries of said circuits, substantially as specified.
15. An electro-magnet having a closed low resistance circuit involving the coarse
wire helix and a high resistance circuit involving a fine wire helix of a comparatively
great number of turns and batteries of said circuits respectively passing the currents
in opposite directions through said helices, substantially as specified.
16. An electro-magnet having a closed low resistance circuit involving a coarse
wire helix adapted to magnetize its coil, and a high resistance circuit passing a current

page_text: through a helix of fine wire around the same core in the opposite directions to that of
said coarse wire helix to hamper or weaken the magnetizing effect of the latter,
substantially as specified.
17. The combination with an electro magnet involving a coarse wire helix in a
closed circuit of low resistance adapted to magnetise its core and a fine wire helix
upon the same core in a high resistance circuit passing its current in opposite direction
to that of the coarse wire helix, of an armature or sub-magnet located within the
poising field of magnetism, substantially as specified.
18. The combination with an electro-magnet having a closed low resistance mag-
netizing circuit, and a fine wire helix in a high resistance circuit, passing a limiting
or demagnetizing current through said helix in the opposite direction to that of the
helix of the low resistance circuit, of an armature or sub-magnet arranged at a suffi-
cient distance from the magnetic pole to respond to the liminations of the magnetism,
substantially as specified.
19. The combination with an electro-magnet having a closed low resistance circuit
and a high resistance circuit passing currents in opposite directions through the
separate insulated helices of an armature or sub-magnet located within the poising
field of magnetism and means of adjustment to regulate the distance between the
electro-magnet and the sub-magnet substantially as specified.
20. A system of electric signaling over-conductors in which an electro magnet
having a closed low resistance circuit is operated by passing the main line current in
a high resistance helix of said magnet in the opposite direction to that of the current
in the low resistance helix thereof substantially as specified.
21. A system of electric signalling wherein an electro-magnet in a closed low
resistance circuit, counterbalancing a distant armature or sub-magnet is actuated by
the operation of the current of the main line passing through a high resistance helix
of said magnet in a direction opposite to that of the current in the helix of the low
resistance circuit to influence the magnetism in the distant or poising field, in which
the armature is located, substantially as specified.
22. The method of electric signaling which consists, first, in passing the main
current and the current of a constantly closed low resistance circuit in opposite
directions through separate insulated helices of the electro-magnet and secondly, in
actuating an armature diaphragm or other sub-magnet at such a distance from the
pole or poles of said electro-magnet that it is subject to the weaker but more constant
magnetic influence and practically outside of the field of residual magnetism, substan-
tially as specified.
23. A method of duplex telegraphy wherein the electro-magnets at the stations are
in constantly closed local voltaic circuits and have helices in the main circuit to
limit the magnetizing influence of the local circuits, and wherein the receiving arma-
tures are located at such distances from the poles of said electro-magnets that they
will respond to the variations of magnetism caused by the limiting action of the main
line current, substantially as specified.
24. The method of using in an electro-magnet a weak main line current of power
insufficient to do practical work upon an armature for the purpose of weakening the
magnetizing action of the current in the low resistance coils to make it of lower
intensity when the main circuit is closed whereby it is prevented from magnetizing
the core to a maximum, substantially as specified.
1-
1207