The use of the iron core renders it possible to produce a high inductive effect with a low resistance coil.
The antenna wire, connected to one spark ball of the induction coil, must be considered to form with the earth, connected to the other spark ball, a condenser.
The average total inductive value of these bridges to received signals is about 40 henrys, and the coil is so arranged that the arms contain three sections or blocks of winding each, two of which are joined up to strap connexions, and the a p :?; .?
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.
Rutherford examined it very carefully, and produced a magnetic detector for electric waves depending upon the power of electric oscillations in a coil to demagnetize a saturated bundle of steel wires placed in it.
Thick) continues from the top of the coil, and after travelling round the various apartments returns to, and is connected with, the lowest part of the boiler coil.
Braun suggested in 1898 that the oscillatory discharge of a Leyden jar should be sent through the primary coil of a transformer and the secondary coil should be interposed between the antenna and an earth connexion.'
38 6), the insulated wires or plates being upheld by masts, its operation is as follows: - When the key in the primary circuit of the induction coil is pressed the transmitting antenna wire is alternately charged to a high potential and discharged with the production of high frequency oscillations in it.
The oscillations are controlled either by a key inserted in the primary circuit of the exciting induction coil or transformer, or by a key cutting in and out of the primary condensers or throwing inductance in and out of the closed oscillation circuit.
Direct radiators are a development of the early coil of pipe; they are made in various types and designs and are usually of cast iron.
4); a current is sent from a battery, E, through one coil of a galvanometer, g, through a high resistance, r, through one of the wires, r, and thence back from office B (at which the wires are looped), through wire 2, through another high resistance, r', through a second coil on the galvanometer, g, and thence to earth.
Incoming currents pass from line through one coil of the relay, the key, and either the battery or battery resistance, according as whether the key is raised or depressed.
In the ordinary methods, a differentially wound receiving instrument was used, one coil being connected with the cable Company and the various Atlantic cables, are worked duplex on method of duplexing a cable was described by Lord Muirhead's plan.
The indicator was connected with a Ruhmkorff coil or other equivalent apparatus, designed to cause a continual succession of sparks to pass between the indicator and a metal plate situated beneath it and having a plane surface parallel to its line of motion.
The magnet between the poles of which the rectangular signal coil moves is built up of a number of thin flat horseshoe-shaped permanent magnets of a special quality of steel, and is provided with adjustable pole pieces.
The signal coil is suspended by fibres and is mounted together with a fixed soft iron core on a brass plate affixed to a rack, with which a pinion operated by a milled head screw engages.
This magnet is excited by an alternating current, and the current induced in the second coil is after rectification sent through an ordinary siphon recorder.
Sending current enters an adjustable mid-point in the g coil and passes through the two halves of the winding to the ends connected to the cable and artificial line respectively.
Hence, by inserting a break-and-make key in the circuit of the battery, coil or dynamo, the uniform noise or hum in the telephone can be cut up into periods of long and short noises, which can be made to yield the signals of the Morse alphabet.
In the primary circuit of the induction coil was an arrangement for rapidly intermitting the current and a key for short-circuiting this primary circuit.
The electromotive force of the coil is, however, great enough to create in these air gaps displacement currents which are of magnitude sufficient to be equivalent to the conduction current required to actuate a telephone.
Instead of inserting the sensitive tube between the receiving antenna and the earth, he inserted the primary coil of a peculiar form of oscillation transformer and connected the terminals of the tube to the secondary circuit of the transformer.
Marconi 2 imparted practical utility to this idea by tuning the two circuits together, and the arrangement now employed is as follows: - A suitable condenser C, or battery of Leyden jars, has one coating connected to one spark ball and the other through a coil of one turn with the other spark ball of a discharger S.
These two circuits are so adjusted that the closed oscillation circuit, consisting of the condenser, primary coil 1 See German Patent of F.
D and spark gap, has the same natural time period of oscillation as the open circuit consisting of the antenna, secondary coil and adjustable inductance.
In this case a closed condenser circuit is formed with a battery of Leyden jars, an inductance coil and a spark gap, and oscillations are excited in it by discharges created across the spark gap by an induction coil or transformer.
One end of the inductance coil is connected to the earth, and some other point on the closed condenser circuit to an antenna of appropriate length.
The lower ends of these wires are connected through the secondary coil of an oscillation transformer to an earth plate, or to a large conductor placed on or near the earth called a " balancing capacity."
Jars or of Leyden panes immersed in oil or some form of air condenser, and the inductance coil or primary circuit of the oscillation transformer consists of a few turns of highly insulated wire wound on a frame and immersed in oil.
In its course it passes through a glass tube wound over with two coils of wire; one of these is an oscillation coil through which the oscillations to be detected pass, and the other is in connexion with a telephone.
Galvanometer coil so that the influence of the latter causes the mirror (through the action of the magnetic needle) to be turned through a small angle in one direction or the other according to the direction of the current through the coil.