Word Finder - coil

definition

Something wound in the form of a helix or spiral.

example

the sinuous coils of a snake

definition

Any intrauterine device (Abbreviation: IUD)—the first IUDs were coil-shaped.

definition

A coil of electrically conductive wire through which electricity can flow.

synonyms

• inductor

definition

Entanglement; perplexity.

definition

To wind or reel e.g. a wire or rope into regular rings, often around a centerpiece.

example

A simple transformer can be made by coiling two pieces of insulated copper wire around an iron heart.

definition

To wind into loops (roughly) around a common center.

example

The sailor coiled the free end of the hawser on the pier.

definition

To wind cylindrically or spirally.

example

The snake coiled itself before springing.

definition

To encircle and hold with, or as if with, coils.

Each coil is attached to a shaft by a bell crank arrangement, and to these shafts there is secured a system of levers similar to that at the transmitter carrying the receiving pencil at the junction.

The use of the iron core renders it possible to produce a high inductive effect with a low resistance coil.

Pull out your refrigerator a few feet and check the condenser coil.

The coil is encased with firebricks and brickwork, and the smoke from the fire is carried, off by a flue in the ordinary s " way.

As they stopped to catch their breath, Dean noticed his rope was down to a single coil.

In circuit with this battery was placed the secondary circuit of an induction coil, the primary circuit of which contained a telephone transmitter or microphone interrupter.

When the oscillations pass through the coil they annul the hysteresis and cause a change of magnetism within the coil connected to the telephone.

The line of circuit passed through the secondary of the induction coil I to the line, from that to the telephone T at the receiving station, 'See Journal of the Telegraph, New York, April 1877; Philadelphia Times, 9th July 1877; and Scientific American, August 181 This term was used by Wheatstone in 1827 for an acoustic apparatus intended to convert very feeble into audible sounds; see his Scientific Papers, p. 32.

The conditions permit of the circulation of the alternating currents of low periodicity, which are used for operating the bells, but in respect of the battery the circuit is open until the subscriber lifts the receiver, when the hook switch, thus released, joins the transmitter with one winding of an induction coil in series across the circuit.

The recorder coil is connected mechanically to a second similar coil, which is suspended between the poles of a laminated magnet, so that the motions of the two are similar.

Over this primary is wound a secondary circuit of five to ten turns which has one end connected to the earth through a variable inductance coil and the other end to an antenna.

Thus, for instance, when using an induction coil or transformer to charge a condenser, it is not generally convenient to make more than 50 discharges per second, but each of these may create a train of oscillations consisting of, say, 20 to 50 waves.

A cord circuit, similar in many respects, including the method .y.^9 Jr '' of operation, but equipped with condensers and impedance coils, in place of the repeating coil, is shown in fig.

But ultimately the coil becomes ventral or endogastric, in consequence of the second torsion movement then apparent.

Close to this the small renal organ (i, mediad) and the larger renal organ (k, to the right and posteriorly) are seen, also the pericardium (1) and a coil of the intestine (int) embedded in the compact liver.

It can be traced back to the intestine i near the surface of the visceral hump, and it is found that the apex of the coil formed by the hump is occupied by the liver h and the stomach v.

From the ovo-testis, which lies near the apex of the visceral coil, a common hermaphrodite duct ve proceeds, which receives the duct of the compact white albuminiparous gland, Ed, and then becomes much enlarged, the additional width being due to the development of glandular folds, which are regarded as forming a uterus u.

In its simplest form an electromagnetic ammeter consists of a circular coil of wire in which is pivoted eccentrically an index needle carrying at its lower end a small mass of iron.

The needle is balanced so that gravity compels it to take a certain position in which the fragment of iron occupies a position in the centre of the field of the coil where it is weakest.

When a current is passed through the coil the iron tends to move nearer to the coil of the wire where the field is stronger and so displaces the index needle over the scale.

Another type of similar instrument consists of a coil of wire having a fragment of iron wire suspended from one arm of an index needle near the mouth of a coil.

When a current is passed through the wire forming the coil, the fragment of iron is drawn more into the aperture of the coil where the field is stronger and so displaces an index needle over a scale.

In the construction of this soft-iron instrument it is essential that the fragment of iron should be as small and as well annealed as possible and not touched with tools after annealing; also it should be preferably not too elongated in shape so that it may not acquire permanent magnetization but that its magnetic condition may follow the changes of the current in the coil.

A much better form of electromagnetic ammeter can be constructed on a principle now extensively employed, which consists in pivoting in the strong field of a permanent magnet a small coil through which a part of the current to be measured is sent.

Such an instrument is called a shunted movable coil ammeter, and is represented by a type of instrument shown in fig.

In this magnetic field is pivoted a small circular or rectangular coil carried in jewelled bearings, the current being passed into and out of the movable coil by fine flexible conductors.

The coil carries an index needle moving over a scale, and there is generally an iron core in the interior of the coil but fixed and independent of it.

The coil is so situated that, in its zero position when no current is passing through it, the plane of the coil is parallel to the direction of the lines of force of the field.

When a current is passed through the coil it rotates in the field and displaces the index over the scale against the control of a spiral spring like the hairspring of a watch.

In the case of ammeters intended for very small currents, the whole current can be sent through the coil, but for larger currents it is necessary to provide in the instrument a shunt which carries the main current, the movable coil being connected to the ends of this shunt so that it takes a definite small fraction of the current passed through the instrument.

Direct reading equidivisional movable coil ammeters can be made in various portable forms, and are very much employed as laboratory instruments and also as ammeters for the measurement of large electric currents in electric generating stations.

In this last case the shunt need not be contained in the instrument itself but may be at a considerable distance, wires being brought from the shunt which carries the main current to the movable coil ammeter itself, which performs the function simply of an indicator, 3.

This second coil is suspended by a number of silk fibres, and to the coil is also attached a spiral spring the other end of which is fastened to a torsion head.

If then the torsion head is twisted, the suspended coil experiences a torque and is displaced through FIG.

F, Fixed coil; D, Movable coil; S, Spiral spring; T, Torsion head; MM, Mercury cups; I, Index needle.

The current can be passed into and out of the movable coil by permitting the ends of the coil to dip into two mercury cups.

If a current is passed through the fixed coil and movable coil in series with one another, the movable coil tends to displace itself so as to bring the axes of the coils, which are normally at right angles, more into the same direction.

This tendency can be resisted by giving a twist to the torsion head and so applying to the movable coil through the spring a restoring torque, which opposes the torque due to the dynamic action of the currents.

If then the torsion head is provided with an index needle, and also if the movable coil is provided with an indicating point, it is possible to measure the torsional angle through which the head must be twisted to bring the movable coil back to its zero position.

In those intended for alternating currents, the main current through the movable coil, whether consisting of one turn or more than one turn, is carried by a wire rope, of which each component strand is insulated by silk covering, to prevent the inductive action from altering the distribution of the current across the transverse section of the conductor.

To avoid the creation of induced currents, the coil frames and the base boards are constructed of slate.

A fixed weight is placed on one coil and the current is varied gradually until the balance is just in equilibrium.

Direct firing is used for the second boiling of the soap mixture; but for this superheated steam may with advantage be substituted, either applied by a steam-jacket round the pan or by a closed coil of pipe within it.

Suppose the switches to be adjusted so that the effective number of turns in the variable coil is loo; the magnetizing forces in the two coils will then be equal, and if the test rod is of the same quality as the standard, the flow of induction will be confined entirely to the iron circuit, the two yokes will be at the same magnetic potential, and the compass needle will not be affected.

The normal position of this coil is with its plane parallel to the lines of force of the field.

Placed inside the return air ductwork is an evaporator coil.

Upon the application of heat to the fire-box coil the water naturally expands and forces its way up into the expansion chamber; but there it encounters the pressure of the confined air, and ebullition is consequently FiG.

A wire carrying an electric current is surrounded by a magnetic field, and if the wire is bent into the form of an elongated coil or spiral, a field having certain very useful qualities is generated in the interior.

A bar of soft iron introduced into the coil is at once magnetized, the magnetism, however, disappearing almost completely as soon as the current ceases to flow.

With suitable arrangements of iron and coil and a sufficiently strong current, the intensity of the temporary magnetization may be very high, and electromagnets capable of lifting weights of several tons are in daily use in engineering works.