Automatic Circuit-controllers for Electric-circuits.CONT
Year: 1889

page_text: Automatic Circuit-controllers for Electric-circuits.
1, STANLEY CHARLES CUTHBERT CURRIE, Electrician, a subject of the Queen of
Great Britain, now residing in Philadelphia, Pennsylvania, U.S.A., do hereby declare
the nature of my invention for AUTOMATIO CIRCUIT-CONTROLLERS FOR ELECTRIC-
CIRCUITS, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
My invention relates to that class of apparatus in which the current is subject to
changes of direction, or sudden reversals of polarity, incident to changes of electro-
motive force in different members of the apparatus, relatively to each other; as, for
instance, in the case of dynamo-electric machines coupled in multiple arc; or a dynamo
and accumulator in the same circuit.
The objects of my invention are, so to organize the apparatus as to secure its prompt
and effective action, at all times, combined with simplicity of construction. These
ends I attain by combining, with the main circuit of a dynamo-electric machine, an
accumulator, or equivalent device, a coil of comparatively thick wire influencing a
magnet; and an armature controlling the main circuit, but energized by a separate
coil of comparatively fine wire, in circuit with the dynamo.
The subject-matter of my invention is hereinafter specifically designated.
The accompanying drawings represent so much only of my improved apparatus as
is necessary to illustrate the subject-matter claimed. The details of construction,
being old and well-known,-unless otherwise indicated-need no particular description.
Figure 1 represents a diagrammatic elevation, partly in longitudinal section, of one
form of apparatus, and
Fig. 2, a similar view of a modified organization.
The drawings show an ordinary shunt-wound dynamo, D, with an accumulator or
secondary battery, B, included in its main circuit, W. W₁, which circuit also comprises
a tubular coil, C, of comparatively coarse wire.
A similar coil, D¹, of comparatively fine wire, is included in a separate circuit, d, d',
connected with the poles of the dynamo-being shown; in fact, as placed in the field-
circuit of the shunt-wound dynamo. In Fig. 1 this fine coil, D', is shown as
encircled by the coarse coil, C, and as encircling, within its bore or cavity, a fixed bar-
magnet, P, preferably a permanent one: as the use of such a magnet prevents the
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page_text: reversals of polarity incident to the use of soft-iron cores, when acted upon by reverse
currents; as hereinafter more fully explained.
A thin sheet or strip, o, of diamagnetic metal-such as brass, for instance, separates
this bar-magnet from a movable core or armature, A, preferably of soft iron-mounted
on an arm or lever, E, preferably of non-magnetic or diamagnetic material-
rocking on a pivot, e, and provided with a counterpoise, G, which tends normally
to hold the armature close to the magnet, P,-as shown in full lines in Fig. 1-which
counterpoise may be adjusted and held in position by a set-screw, g.
The opposite end of the rocking-arm, E, carries an insulated fork, F, of conducting
material the prongs, ff, of which, when depressed, can rest in mercury-cups, f³, f³,
.in the main-circuit, which normally remains open.
Fig. 2 shows the circuit-closing device as consisting of abutting springs, ƒ, ƒ¹, or
mercury-cups, f³, f³; a spring, G, as constituting the counterpoise; and the
coils, C, D', as wound parallel and end to end, instead of one within the other; these
being all well-known equivalents.
The coils, armature, and magnets, it will be observed, are all of substantially the
same length in Fig. 1, the winding being equivalently increased in the coils shown in
Fig. 2.
The following is a description of the operation of the apparatus; the object, it will
be understood, being to complete the main-circuit whenever the electro-motive force
of the dynamo exceeds that of the accumulator; and to maintain this position as long
as their relative condition remains unchanged; and promptly to open the main-
circuit and thus cut out the dynamo--whenever the electro-motive force of the
accumulator exceeds that of the dynamo; thus preventing the injurious action of
reverse currents.
When no current traverses the coils, C, D¹, the armature, A, is normally attracted
by the permanent magnet, P, and held close thereto. This lifts the forks, f, f, and
breaks the main-circuit-as shown. Now when the dynamo starts, as soon as its
electro-motive force rises to the requisite intensity-in excess of that of the battery-
the fine-wire coil, D',-being properly wound for that purpose-creates in the
armature, A, magnetism similar in polarity to that of the permanent magnet, P; the
armature consequently is repelled by the magnet, and forced to the opposite side of
the cavity in the coils. The intensity of the field-magnets, or-in other words-
the electro-motive force required to do this work, can be regulated by adjusting the
counterpoise, G, as hereinbefore explained. This repulsion of the armature closes the
main-circuit as shown in dotted lines in Fig. 1-by inserting the forks in the mercury-
cups. As the coarse coil, C,-which is included in the main-circuit-is wound
correspondingly with the fine coil, D³, both co-operate in actuating the armature, and
in maintaining the magnetism of the permanent magnet, P, and the main-circuit
remains closed as long as this condition exists.
Now, should the electro-motive force of the dynamo diminish,--from any cause-
until it only equalled that of the accumulator, the current in the coarse coil, C, would
cease or fall to zero, while the current in the fine coil would be insufficient to maintain
the repulsion of the armature; which would promptly fall, and thus break the main-
circuit.
On the other hand, should the battery-current become so strong as to reverse the
current in the main-circuit, the polarity of the coarse coil, C, would at once become
opposed to that of the fine coil, 1); the preponderating influence of the permanent
magnet, P, would at once attract the armature, and break the main-circuit. This
property constitutes the main reason for the use of a permanent magnet, as it retains
its polarity, instead of having it reversed by reversals of the current. Ordinarily the
currents of the coils, C, D, reinforce the polarity of the permanent magnetism, and
thus prevent its loss or change.
The advantage of utilizing the repulsive force of the magnets and currents instead
of operating normally by attraction, as heretofore, is so great and so obvious as readily
to be appreciated by those skilled in the art-when indicated.
When operating by attraction, sudden and large reversals of polarity frequently

page_text: result in still retaining the circuit closed, but, with my organization, such a result
is practically impossible, as both the currents and permanent magnets co-act to open
the circuit.
Another advantage incident to my organization is, that the currents are so regulated
that the action of the fine coil alone is just sufficient to close the contacts or immerse
the points of the forks into the mercury-cups, the buoyancy of which prevents deep
immersion, until the large coil or main current acts. When the forks become
deeply immersed and full contact is assured, the larger the current, the deeper the
immersion, and the better and larger the contact. As the main current decreases the
immersion of the contacts decreases, until, at the moment the current ceases, they
barely touch, and the circuit can quickly and readily he broken. To this advantageous
I have
mode of operation the repulsive organization essentially contributes.
practically demonstrated, with such an apparatus, that contact breaks when the
pressure or electro-motive force of the generator and accumulator is balanced, and
that the contact breaks so gradually as effectually to prevent sparking.
The manner in which this automatic breaking of the main-circuit prevents
injurious effects on the dynamo is well understood, and various ways of attaining
this result heretofore have been devised. I do not, therefore, broadly claim attaining
this result; nor do I broadly claim breaking a main-circuit by an armature controlled
by a separate circuit.
•
And now having particularly described and ascertained the nature of this said
invention, and in what manner the same is to be performed, I declare that what
I claim is-
1. The combination, substantially as hereinbefore set forth, of a dynamo-electric
machine, an accumulator, and an energizing-coil, all in the main-circuit; a second
energizing-coil, (in a separate or branch-circuit) adjacent to, and parallel with the
main-circuit coil; a permanent magnet within said coils; a soft-iron armature, also
within said coils; and a circuit-controller or switch in the main-circuit, controlled
by sid armature.
2. The combination, substantially as hereinbefore set forth, of a shunt-wound
dynamo, an accumulator, and an energizing-coil, all in the main-circuit; a second
energizing-coil (in a constantly closed field-circuit) coincident with the inain-circuit
coil an armature vibrating within both coils; a permanent magnet actuating the
armature, and the main-circuit switch, controlled by said armature.
3. The combination, substantially as herein before set forth, of a dynamo, an
accumulator, and an energizing-coil of coarse wire, all in the main-circuit; a second
energizing-coil of fine wire (in a separate or branch-circuit); a permanent magnet ;
an armature within the coils, and the main-circuit switch.
4. The combination, substantially as hereinbefore set forth, of the main-circuit
coil, the branch-circuit coil coincident therewith, the permanent magnet, and the
soft-iron armature, both enclosed by the coils, and the main-circuit switch, controlled
by the armature.
5. The combination, substantially as hereinbefore set forth, of the main-circuit
coil, the concentric coacting branch-circuit coil, the permanent magnet enclosed
therein, the armature vibratable laterally relatively to the permanent magnet, and
the interposed diamagnetic plate, which prevents the adhesion of the magnet and
armature.
6. The combination, substantially as hereinbefore set forth, of the co-acting
concentric coils, the permanent magnet therein, the armature vibratable within the
coils, the arm, pivot and counterpoise of the arinature, and the circuit-controller
carried by said arm.
7. The automatic circuit-controller herein before described, consisting of the
combination of a dynamo, an accumulator, and an energizing-coil, all in the main-
circuit; a second energizing-coil (in a separate or branch-circuit) concentric and
co-acting with the main-coil, a permanent magnet within said coils, an armature
vibratable therein, an arm on which said armature is mounted, a pivot on which said

page_text: armature rocks, a counterpoise normally holding said magnet and armature together,
and a switch controlling the main-circuit, also mounted on said arm, and controlled by
the vibrations of the armature, substantially as herein before set forth.
8. The combination, substantially as hereinbefore set forth, of the energizing-
coil, its fixed permanent magnet-core, and its movable soft-iron armature-normally
similarly polarized and vibratable laterally within the coil.
9. An automatic counterpoised circuit-controlling switch, normally closed and held
closed by the repulsive co-action of permanent and electro-magnets, while the
current is flowing in the proper direction in the circuit closed; but automatically
opened and heid open by the co-operation of gravity and magnetic attraction, on the
cessation or reversal of the current which closed it, substantially as hereinbefore
set forth.
Dated this 20th day of February 1889.