Inductance sentence example
If L and N are the inductances of any two circuits which have a coefficient of mutual inductance M, then M/-/ (LN) is called the coefficient of coupling of the circuits and is generally expressed as a percentage.
These mechanical qualities correspond to inductance and capacity in electric circuits.
The shunts usually employed with the drum relay (referred to above) have each a resistance of about 30 ohms and an inductance of 20, 30 and 40 henrys respectively.
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.
It can be shown that if two circuits, both having capacity (C) and inductance (L), are coupled together inductively, then, when oscillations are set up in one circuit, oscillations of two periods are excited in the other differing in frequency from each other and from the natural frequency of the circuit.Advertisement
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.
In many cases additional condensers or inductance coils are inserted in various places so that the arrangement is somewhat disguised, but by far the larger part of the electric wave wireless telegraphy in 1907 was effected by transmitters having antennae either inductively or directly coupled to a closed condenser circuit containing a spark gap.
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.
When electric oscillations are set up in an open or closed electric circuit having capacity and inductance, and left to themselves, they die away in amplitude, either because they dissipate their energy as heat in overcoming the resistance of the circuit, or because they radiate it by imparting wave motion to the surrounding ether.
This last circuit has a natural frequency of its own which is numerically measured by I/27r-!(CL), where C is the capacity of the condenser and L is the inductance of the circuit.Advertisement
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.
The receiving arrangement consists of an antenna which is connected to earth through the primary coil of an oscillation transformer and a variable inductance.
His proposed radiator and absorber consisted of two wing-shaped plates of copper, the transmitter plates being interrupted in the centre by a spark gap, and the receiver plates by an inductance coil from the ends of which connexions were made to a coherer.
When the methods for effecting this had been worked out practically it finally led to the inventions of Slaby, Braun and others being united into a system called the Telefunken system, which, as regards the transmitter, consisted in forming a closed oscillation circuit comprising a condenser, spark gap and inductance which at one point was attached either directly or through a condenser to the earth or to an equivalent balancing capacity, and at some other point to a suitably tuned antenna.
Duddell discovered in 1900 that if a continuous current carbon arc had its carbon electrodes connected by a condenser in series with an inductance, then under certain conditions oscillations were excited in this condenser circuit which appeared to be continuous.Advertisement
Across the arc is a transverse or radial magnetic field, and the electrodes are connected by an oscillatory circuit consisting of a condenser and inductance.
From the known value of the capacity in that position and the inductance the frequency can be calculated.
An improvement was effected in this respect by the introduction of the " bridging " system, in which the bells possessing high inductance are placed in parallel between the two wires of the circuit.
In one arrangement, now in extensive use, each telephone set is fitted with a relay of high inductance which is bridged across the circuit in series with a condenser.
In circuits possessing high resistance and capacity and low inductance per mile, telephonic currents are rapidly attenuated, and the higher the frequency the more rapid is the attenuation.Advertisement
Oliver Heaviside showed mathematically that uniformly-distributed inductance in a telephone line would diminish both attenuation and distortion, and that if the inductance were great enough and the insulation resistance not too high the circuit would be distortionless, while currents of all frequencies would be equally attenuated.
Pupin showed that by placing inductance coils in circuit, at distances apart of less than half the length of the shortest component wave to be transmitted, a non-uniform conductor could be made approximately equal to a uniform conductor.
The introduction of inductance coils into such circuits renders them more susceptible to trouble from atmospheric electricity and more sensitive to leakage variations.
The problem, however, of constructing a deep-sea cable satisfactorily, with suitable inductance coils inserted at short distances apart, is a difficult one, and one which it cannot be said has been solved.
It is also necessary to notice that shunt instruments cannot be used for high frequencies, as then the relative inductance of the shunt and wire becomes important and affects the ratio in which the current is divided, whereas for low frequency currents the inductance is unimportant.Advertisement
In those cases in which the power - absorbing circuit is inductive, the coil of the wattmeter connected across the terminals of the power-absorbing circuit must have an exceedingly small inductance, else a considerable correction may become necessary.
In the 9th series (1834) he announced the discovery of the important property of electric conductors, since called their self-induction or inductance, a discovery in which, however, he was anticipated by Joseph Henry in the United States.
He added definiteness to the idea of the self-induction or inductance of an electric circuit, and gave a mathematical expression for the current flowing out of a Leyden jar during its discharge.
No one has yet been able to isolate positive electrons, or to give a complete demonstration that the whole inertia of matter is only electric inertia due to what may be called the inductance of the electrons.
The circuit model for the loop wire is therefore best seen as series resistance and inductance, and shunt capacitance.
In 1876, Heaviside took account of self inductance, obtaining the equation of damped harmonic motion known as Heaviside's Equation of Telegraphy.
For example, halving the number of primary turns reduces the primary inductance to approximately one quarter of its previous value.
Even straight wire has some inductance, and there is always at least some capacitance between two wires in proximity to each other.
The circuit also contains a distributed inductance formed from the tracks making up the structure.
To increase inductance from minimum to maximum the dial must be rotated first from 100 to 200 then from 100 to 0.
The disadvantages of the air gap are - More turns are required to obtain a given inductance.
All the new bi-wire cables in the Original Range feature an enhanced geometry that minimizes cable inductance by precisely spacing opposing sets of conductors.
The comparatively low currents also make the inverter less sensitive to layout and stray inductance.
The good news is that in many cases these voltages can be measured through mutual inductance.
All Ecosse ' speaker ' cables exhibit low resistance (which together with low inductance) ensuring smooth, musically accurate performance.
All that matters during the initial rising edge is the effective inductance of the disk, which is the same in each case.
The resonant charging properties depend on the chosen tank capacitor value and the leakage or ballast inductance of the supply.
This being the value which will resonate at 50Hz with the 159 Henry leakage inductance of the transformer.
The main advantage of this construction method is that it reduces the series inductance because the capacitor plates are not rolled into a spiral.
The input return loss on 432 is slightly over 4 dB on 432 with the same source inductance.
At this frequency a parallel resonant circuit is formed between the primary inductance and the net capacitive reactance reflected back from the secondary.
By this arrangement of the coil winding, similar sections can be thrown in or out of circuit with both arms, and also so combined that any amount of inductance suitable to every class of cable may be obtained.
If the two circuits are in tune so that the numerical product of capacity and inductance of each circuit is the same or C L, = C L +CL and if k is the coefficient of coupling then the natural frequency of each circuit is n = I /2w / (CL), and when coupled two oscillations are set up in the secondary circuit having frequencies n and n2 such that n = n0/ (i - k) and n = nh,/ (I +k).
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.
On the other hand, if a closed oscillation circuit is constructed having capacity and considerable inductance, then oscillations can be set up in it by very small periodic electromotive forces provided these have a frequency exactly agreeing with that of the condenser circuit.
The success so far achieved in isolating electric wave telegraphic stations has been based upon the principles of electric resonance and the fact that electric oscillations can be set up in a circuit having capacity and considerable inductance by feeble electromotive impulses, provided they are of exactly the natural frequency of the said circuit.
The Fleming closed circuit wave meter, called by him a cymometer, consists of a sliding tube condenser and a long helix of wire forming an inductance; these are connected together and to a copper bar in such a manner that by one movement of a handle the capacity of the tubular condenser is altered in the same proportion as the amount of the spiral inductance which is included in the circuit.
Again the shunt circuit must have practically zero inductance and the series or current coil must be wound or constructed with stranded copper wire, each strand being silk Covered, to prevent the production of eddy currents in the mass of the conductor.