Throwing off the belt and disconnecting the wires, he spun the armature around by hand.
This machine was laid on its side, with the armature end coming out at the front of the locomotive, and the motive power was applied to the driving-axle by a cumbersome series of friction pulleys.
He split up the iron core of the armature into thin laminations, separated by paper, thus practically suppressing Foucault currents therein and resulting heating effect.
The armature circuit had a switch in it which permitted the locomotive to be reversed by reversing the direction of current flow through the armature.
The relay coils are connected by wire to the spring piece, S, and the armature lever is connected to earth.
A switch in the armature circuit enabled the motorman to reverse the direction of travel by reversing the current flow through the armature coils.
The next resort of Edison was to belts, the armature shafting belted to a countershaft on the locomotive frame, and the countershaft belted to a pulley on the car-axle.
The armature is cylindrical, and built up of flat rings stamped out of soft sheet iron, eight notches in the same being provided to fit over the arms of the spider keyed to the shaft.
The conditions just stated are present in dynamos for heavy current work, where the speed of cutting of lines is low and the armature conductor large in section.
Projections existing on the armature between which the conductors are placed have a like effect, and enable us to employ heavy bars or bundles of wire without much difficulty from local currents.
The best results would be obtained when the armature conductor does not project beyond or quite fill the depth of groove between the projections.
A flat soft iron plate armature is hinged so as to come up against the pole pieces when attracted.
The armature consists of a bony case, partly composed of solid buckler-like plates, and partly of movable transverse bands, the latter differing in number with the species, and giving to the body a considerable degree of flexibility.
The object of the adjusting screw is to push and hold the armature close up to the ends of the magnets, if it seems necessary.
This operation of vibrating the armature is repeated with great rapidity, alternately breaking and re-establishing the circuit, by the action of the current.
In a motor an excess of mechanical work which causes the armature to turn too slowly and produces heat.
A permanent magnet and a revolving armature for generating a current.
D of the armature are closely approaching the positive and negative magnets, on one side; and the positive magnets C are nearing the positive and negatives on the other side.
An electric call produced by a rapidly moving armature of an electro-magnet.
The result is that the electrode, connected with the armature of the magnet, is drawn away from the other electrode, and the arc is formed, between the separated ends.
After the armature magnets have gone to the positions in Fig.
The figure shows a single loop of wire, on the armature core connected directly to the source of electricity.
According to Lenz' law, the direction of the current in the armature of a dynamo is such as to oppose the motion producing it.
The effect of embedding the armature inductors in slots is to distort the magnetic field as shown in fig.
The time required for commutation, or the angle through which the armature must turn to commute the current in one coil.
In the operation of a dynamo with load, the induced current flowing in the armature winding, converts the armature into an electromagnet setting up a field across or at right angles to the field of the machine.
Rear view ofarmature of a large dynamo built by the General Electric Co.
In the case of either a motor, or a dynamo used as a motor, the direction in which the armature will rotate is easily found by the left hand rule, as illustrated in fig.
F, and leaves it at E, thence it flows to the armature brush B, through armature to brush A, and from here back to the dynamo.
The proper position of the brushes, if there were no field distortion and self-induction in the armature coils, would be in the normal neutral plane.
When a motor is in operation, the wires around the periphery of its armature "cut" the magnetic lines of force produced by the field magnet exactly as in the case of the dynamo.
The action of the hammer is precisely the same as that of the armature of an electric bell.
Large dynamos have four, six, eight, or more field magnets set inside a casing, from which their cores project towards the armature so as almost to touch it (Fig.
During the impression of a dot by the Morse inker, contact is made and broken repeatedly; but as the armature of the inker is heavy and slow to move it does not vibrate in time with the relay and tapper.
Such a form of armature would be unsuitable for large dynamos, which accordingly have a number of coils wound over their drums, at equal distances round the circumference, and a commutator divided into an equal number of segments.
On electric cars the motor is generally suspended from the wheel truck, and a small pinion on the armature shaft gears with a large pinion on a wheel axle.
A magnet, whirled outside the bell-glass, draws round the iron armature on the pivoted table, and consequently revolves the record, on the surface of which a very thin coating of gold is deposited.
The field magnets usually revolve inside a fixed armature (the reverse of the arrangement in a direct-current generator); or there may be a fixed central armature and field magnets revolving outside it.
The circulation of current magnetizes M, which attracts the iron armature A attached to the spring S, and draws the hammer H towards the gong.
The armature is revolving in a clockwise direction, and y z, therefore, is moving downwards.
The superficial armature of the skeleton in the Coelodendrida is rather simple, and by no means so manifold and differentiated as in the more highly developed Coelographida.
Their structure and armature is the same as in the similar Aulosphaerida.
In some species this peculiar armature attains an extraordinary size, whilst the shell itself is very small, as in Dorcadospyris dinoceras (Pl.
The genus Lophocyrtis differs from its ancestral form Theocyrtis only in the armature of the cephalis, bearing instead of a single horn either two divergent horns, or a bunch, or coronal of numerous spines.
The genus Lophocorys differs from its ancestral form, Theocorys, only in the armature of the cephalis, bearing either two divergent horns, or a corona of several radial horns.
The genus Lophophaena differs from the nearly allied Sethocorys and Dictyocephalus only in the armature of the large cephalis, which bears a group of large horns, often arranged in a corona of radial spines.
Under such conditions the transmission would necessarily be slow, because an armature time will be lost at each repeater.
He not only set forth the theory, but he constructed a line of bell-wire 1060 feet long and worked his magnet by making the armature strike a bell for the signals, which is the basis of the modern "sounder.
In other cases the armature revolves and the field-magnets are stationary.
It was all constructed of wood except the magnet and its armature and the embossing-point, which latter was made of the end of a nail.
In the dynamo there is a discharge every time the electromagnet of the armature cuts through the lines of force of the magnetic field, and in the galvanic battery every time a molecule is broken up and its little measure of energy is set free.
The current for power purposes is generated in a large stationary armature about ten feet in diameter and of the same depth as the revolving ring.
Regarding each repeater as a key, when Chicago depresses his key the armature of the next repeater must act, and then the next successively, and all of this takes time, although only a small fraction of a second.
The sun is the field-magnet, and the earth is the revolving armatureof nature's great dynamo-electric machine.
When the keys at both ends are closed the batteries are active and the armatures or "keepers" are attracted so that the armaturelevers rest on the forward stops.
They undergo considerable changes with age, the caudal armature being developed by degrees.
Many of the species have an armature much like that of the sturgeon, but here the resemblance ends, the bony plates in the two cases being without doubt independently evolved.
Usually the Ganoids have an armature of bony plates, diamond-shaped, with an enamel like that developed on the teeth.
The pubic bone is more elongate, and in all the species some sort of armature is developed on the side of the tail.
To Caranx, Carangus, and a number of related genera, characterized by the bony armature on the narrow caudal peduncle, a host of species may be referred.
In Vomer, Selene, and Chloroscombrus the bony armature of the tail, feeble in Alectis, by degrees entirely disappears.
In Alectis ciliaris, the cobbler-fish, or threadfish, the armature of the tail is very slight and each fin has some of its rays drawn out into long threads.
In Prionurus (microlepidotus) of the tropical Pacific the armature is still more degraded, about six small plates being developed.
The motor armature is mounted upon a hollow shaft, which is connected with the compensating gear.
The armature and field magnets of the motor, which are the parts that develop the power, are located at A and the compensating gear is placed at B.
One form has its revolving portion or armaturecomposed of a number of sheet iron disks wound as usual with three coils crossing near the shaft.
An arrangement of parts somewhat analogous to that of a horseshoe electro magnet and armature is shown in Fig.
The commutator short-circuits the armature coils in succession in the proper positions to utilize the repulsive effect set up by the currents which are induced in them by the alternations in the field coils.
The position of neutrality varies with the type of the machine owing to the fact of armature reaction, which distorts the magnetic field.
We must therefore connect the commutating poles in series with the armature, when their windings will carry the full armature current.
Being made of lead, the armature can be bent this way and that, and twisted about, even after it has been covered with clay.
When this is done the bust will be easily freed from its peg, and the armature attached to it.
He then takes portions of these strips and applies them bit by bit to the armature and the transverse bar, thus gradually building up the general shape of the head and shoulders.
Then the magnet lets go and the armature springs back, making contact once more and setting the current flowing again.
The vibration of the armature itself also causes a humming sound of a similar note or tone to that heard in the telephone, but it must be clearly understood that these two sounds are quite different.
When the current flows in the wire the armature is pulled towards the poles against the force of the spring, but when the current ceases the magnet lets go and the armature, urged by the spring, swings back again.
These actions repeat themselves over and over again quite automatically, and the hammer which is attached to the armature vibrates accordingly.
Behind the armature is a little post through which passes a screw tipped with platinum, and in operation this screw is advanced until its point touches a small plate of platinum carried by the armature.
A moment later, however, the armature moves, breaks the contact with the screw and stops the current.
While the armature winding is thus short-circuited there will be practically no generation of current.
When the current reaches its maximum value, because of the armature being in the best position, the cam operates the interrupter and the points are separated, breaking the short circuit which has existed in the primary winding.
The armature of a practical magneto, therefore, differs materially from that shown in the diagram.
In the twelve-cylinder machine two magnetos of the ordinary revolving armature or two-spark type, each supplying six cylinders, are fitted as outlined at Fig.
The flow of magnetism is through the magnet from south to north and the circuit is completed by the flow of magnetic influence through the air gap or metal armature bridging it from the north to the south pole.
Another advantage of the flexible coupling is that the vibration of the motor will not be as fully transmitted to the armature shaft on the magneto as in case a rigid coupling is used.
The electro-motive force varies as to the length of the armaturewinding and the number of revolutions at which the armature is rotated.
The true high-tension magneto differs from the preceding inasmuch as the current of high voltage is produced in the armature winding direct, without the use of the separate coil.
An electric motor can be turned into an electric generator by simply reversing the direction in which the armature rotates--that is, any electric machine is either a generator or a motor.
In consequence of the backward rotation a current is generated in the armature coils, and this current, as it traverses the field coils as well as those of the armature, causes the polarity of both parts to increase.
The magnetism, however, does not die out entirely; a small residue is always left, although it is never sufficient to produce rotation, and even if it were it could only cause the armature to revolve through one quarter of a turn.
To enable the motor to give a strong torque and run at a slow speed the number of poles in the field and armature is increased.
The commutator is secured to the armature shaft, and the brushes through which the current enters and leaves are held stationary; keeping this fact in mind, it can be seen at once that in Fig.
If the load is increased the motor will run slower and the current will become greater, thus increasing the pull, but the armature will continue to rotate until the current becomes so great as to burn out the insulation.
As it is necessary that the armature shaft and the axle be kept in perfect alignment, the motor casing M is provided with suitable bearings for both, those for the armature shaft being marked P P in Fig.
When the field wire is very much finer than that of the armature the machine is what is known as shunt wound, which means that only a small portion of the current that passed through the armature passes through the field coils.
A piece of brass wire, O, is soldered to the diaphragm disk B and the soft-iron armature H, to connect them solidly.
Solder the needle to the shaft, and then place a sufficient quantity of solder on the broad end to balance the system perfectly and allow it to come to rest in any position when the armature B is not influenced by any magnetic field.
But it must always be borne in mind that in order to reverse the direction of rotation, the current must be reversed in the armature only or in the field only, not in both.
The connections to the bell magnets 1, 2, and 3 should be direct to the binding posts so that the armature will not vibrate, but give one stroke.
The exact center of the space the armature is to occupy is then marked on each of these pieces, and a hole is drilled in each, having the same diameter as the ends of the armature shaft.
Illustration: Diagram of the Winding on the Armature and Detail of the Field Laminations (Fig.
Weston in 1882 improved this method by making the armatureof separate and insulated sheets of iron around which the coil is wound.
They were then carried through the receiving armature and reproduced on the receiving diaphragm, with all the same characteristics of pitch, loudness and quality.
Gramme made his armature of iron rods to prevent its destruction by heat.
The contact maker works on the center, m, having an armature on its opposite end.
A moment later it was speaking out its weighty and secret messages, innocently, authoritatively, almost triumphantly, it seemed to the eavesdropper, bending over the glimmering armature lever.
Then, with a deft movement or two he released the binding of the armature lever screws, and the next moment the instrument felt the pulse of life, and spoke out clearly and distinctly.
If the connecting piece of iron, the armature, is removed, the bar immediately loses all its magnetism, and will not support even the armature itself.
This armature is pivoted at its center, and thus executes vibrations synchronously with those of the pendulum.
The armature of the relay oscillates between two stops whose distance apart is capable of fine adjustment.
It is clear, therefore, that the impulse is independent of the strength of the current in the relay, provided that the armature is brought up to the stop on either side.
There is, therefore, a rush of current into the transformer, and if it is connected to an alternator of low armature resistance the fuses are generally blown and other damage done.
This armature carries a small hammer or tapper, which, when set in action, hits the tube on the under side, and various adjusting screws are arranged for regulating exactly the force and amplitude of the blows.
Mr. Marconi, in his original receiving instruments, placed an electromagnet under the coherer tube with a vibrating armature like an electric bell.
This movement may be effected by the attraction of an iron armature by an electromagnet, or by the varying magnetism of the core of the coil, or it may be effected more slowly by hand.
The armature can not be seen very well, as it is covered by the brush holders and their supporting frames, but it is located within the ring G in the position designated by A.
As was explained in the first article, an electric motor can be made to act as a generator of electric current by simply reversing the direction in which the armature revolves.
If the current is doubled the magnetic force of the armature is nearly doubled, and so is that of the field magnet, therefore the pull between the poles is nearly four times as great.
If we do not desire to reverse the direction of rotation, the result can still be attained by reversing the direction in which the current passes through the armature coils.
In this case the fan is secured to an extension of the armature shaft of the motor.
The dynamo armature is attached to the crankshaft of the engine by which it is rotated in a magnetic field to produce the desired amount of electricity.
This magnetism attracts the iron armature attached to the spring A, and it is suddenly pulled forward with energy sufficient to cause the tapper to strike the gong.
With each movement of the armature a spark forms at the contact which wears away the point, so that to insure good service these points must be made of refractory material.
The noise, from which the device takes its name, is produced by the armature and spring in making and breaking contact.
Electric bells are often objectionable as signal calls because of their clamor, but with the removal of the bell the vibrating armature serves equally well as a signal but without the undesirable noise.
When the current ceases to flow in the magnet coils, the cores are demagnetized and the armature is drawn back by the spring A to the original position.
As the armature moves forward, the spring contact at F is broken and the current stops flowing through the magnet coils.
In the electric dynamo, the generation of the current is due to impulses that are induced in the wires of the dynamo armature as they pass through a magnetic field of great intensity.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "armature" in a variety of sentences. We hope that you will now be able to make sentences using this word. Other words: armor; cortex; device; generator; harness; mail; panoply; parts; relay; shell; shield
