The two circuits have a certain mutual inductance M, and each circuit has self inductance L1 and L2.
The general theory of an oscillation transformer containing capacity and inductance in each circuit has been given by Oberbeck, Bjerknes and Drude.
The type of transmitter is a simple rotary gap, indirectly excited spark and provided with nine taps on the inductance coil of the closed oscillating circuit.
In his wireless installation, a network of insulated wires, suspended in the air above, is one plate, the earth is the other; and the two are connected by an inductance coil.
Notwithstanding this defect of the theory, which is after all not so serious as certain difficulties of exact calculation of the self-inductance of the discharging conductor, the periods of vibrators can be very accurately found.
The inertia or mass of the bob is the analogue of what Thomson called the electromagnetic inertia of the coil and connections; what is now generally called the self-inductance of the conducting system.
It is equally hard if L-C has smaller capacity and inductance than ab so that it naturally oscillates faster.
It also depends upon how muchinductance there is in the coil which you have in the antenna circuit.
To decrease the frequency we can either increase the capacity or increase the inductance or do both.
If it is way inside, the total inductance which the two coils offer is either larger than the sum of what they can offer separately or less, depending upon whether the windings are in the same direction or opposite.
We know that fact because we know that an iron core increases the inductance and so chokes the current.
Number Inductance in Wave length with antenna of of turns.
In Table I there is given, for each of several values of the inductance of the primary coil, the shortest and the longest wave-lengths which you can expect to receive.
There is one more effect of inductance which we must know before we can get very far with our radio.
Suppose you wind two inductance coils and connect them in series.
The longer the wire the larger will be the inductance but unless the length is hundreds of feet there isn't much inductance anyway.
Illustration: Fig 47d] That's the same sort of thing that happens in the case of the inductance and condenser in the oscillating audion circuit except for one important fact.
I have assumed that you will have this number of turns per inch on your coils and calculated the inductance which you should get for various numbers of total turns.
To receive at longer wave-lengths you will need to increase the inductance of your antenna so that it will be tuned to a lower frequency.
Curve showing variation of current by increasing the frequency in a circuit having inductance and capacity.
If inductance and capacity be present in a circuit in such proportion that the effect of one neutralizes that of the other, the circuit acts as though it were purely non-inductive and is said to be in a state of resonance.
When wound in this manner, a coil will have little or no inductance because each half of the coil neutralizes the magnetic effect of the other.
If an alternating current, having a frequency of 60, be impressed on a coil whoseinductance is .
Impedance diagram for circuit (of above example) containing inductance and capacity.
An inductance would cause a lag, a capacity would cause an advance, in phase.
UHF reception should be tried with and without the inductance wire to obtain the best overall results.
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.
If a conductor of capacity C has its terminals connected by a wire of resistance R and inductance L, it becomes important to consider the subsequent motion of electricity in the wire.
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 receiving station is provided with an aperiodic circuit, which consists of an inductance F', condenser C', and a thermodetector N.
The closed oscillatory circuit consists of an inductance F, spark-gap G, and a block condenser C.
The condenser C' prevents the continuous current produced by the detector from flowing through the high frequency circuit; P is the primary of the aerial {33} inductance and F the secondary.
X is the generator, F inductance, C condenser; the aerial inductance T is connected by the aerial A and earth E.
What inertia is to a material bodyinductance is to an electric current.
The shunt consists of a wire leading from the copper to the carbon rod with a condenser and an inductance coil inserted in it.
The advantage of this is that by introducing condensers the capacity of which can be varied, and coils the inductance of which can be varied, into the oscillation circuit it becomes possible to "tune" the circuits effectively.
In the latter there are almost insuperable obstacles caused by the capacity and inductance of the circuit, while in the wireless method there is very little difficulty.
In this manner we can communicate to the bottom end of the long spiral wire a series of electric impulses, the time period of which depends upon the capacity of the jar and the inductance of the discharge circuit.
This rod is insulated, and at the lower end the wire is connected to a Leyden jar circuit, consisting of a Leyden jar or jars and an inductance coil, L, the inductance of which can be varied.
One end of this secondary circuit is attached to the aerial and the other end is connected to the earth through a variable inductance coil.
This high frequency can only be obtained either by greatly reducing theinductance of the primary discharge circuit, or reducing the capacity.
In some cases, the inductance of the primary coil alone is sufficient to start the break in operation, but with voltages above 50 or 60, it is generally necessary to supplement the inductance of the primary coil by another inductive coil.
The chief difficulty we have to contend against in the construction of an effective oscillation transformer is the inductance of the primary circuit and the magnetic leakage that takes place.
Accordingly, the inductance and capacity of the lateral branch of the transmitter is altered until the hot wire ammeter in the base of the aerial shows the largest possible current.
The terminals of the condenser which is inserted in the middle of the secondary circuit of the oscillation transformer are connected through two small inductance coils with a relay and a single cell.
The dash is really a series of closely adjacent dots, which run together in virtue of the inertia and inductance of the different parts of the whole receiving apparatus.
All wires which are wound into coils, such as electromagnets, possess inductance in a greatly increased degree.
The inserted inductance remaining constant, its benefits may become detriments when the other two "constants" change.
Both observations in this test show that the amount of current entering and emerging from the line decreased as the inductance increased.
There are two ways in which inductance might be introduced into a telephone line.
To distinguish the two kinds of reactance, that due to the capacity is called capacity reactance and that due to inductance is called inductive reactance.
Describe Professor Pupin's method of insertinginductance into the telephone line.
The listening observer will notice that the sounds reaching his ear steadily grow faint as the inductance in the line increases and the speaking observer will notice the same thing through the receiver in series with the line.
Test of Line with Varying Serial Inductance] Capacity and inductance depend only on states of matter.
But the total inductance must stay close to zero or utterly violent and explosive forward thrust would develop, and it was calculable only in thousands of gravities.
When a plus inductance in series made the self-inductance zero, neither plus nor minus, the immensely powerful device became docile.
A single variable inductance in series with the windings handled everything.
As soft copper has greater conductivity per unit of area than any of the other available metals, it clearly has an advantage over all of them as to inductance and increase of resistance with alternating current.
So, too, an increase of inductancein a circuit adds to the work of an arrester in breaking an arc.
As a rule it may therefore be said that inductance will seldom increase the weight of line conductors, or the loss of power therein, by more than ten per cent.
Inductance increases with the frequency of the current in a conductor, and in each of the three systems just considered the frequency is sixty cycles per second.
Thus it happens that inductance makes it desirable to bring the parallel wires of a circuit close together, while the leakage of energy from wire to wire makes it desirable to carry them far apart.
The amount of current increase depends on both the inductance of the line itself and also on the character of its connected apparatus.
As a result of these facts, it is not desirable or even practicable to use inductance as a factor in the calculation of the resistance or weight of a transmission line.
As inductance increases directly with the length of circuits, these very long lines are especially subject to its influence, yet it was thought that the advantages of a single circuit more than offset its disadvantages in each case.
Experience with such systems shows, however, that the increase of line current due to inductanceis often not above five and usually less than ten per cent of the current that would flow if there were no inductance.
Instantly Dick was on his feet, Leyden jars and inductancecoils forgotten.
Just as with the weighted rope this circuit transmitted its current much more efficiently than if the inductance coils had been absent.
The intervals at which inductance coils should be placed depend upon the circumstances of each case.
It was in ascertaining that law so as to know where to place hisinductance coils that Professor Pupin arrived at success.
Example of wiring showing where inductance is negligible, and where it must be considered in wire calculations.
It can be maintained constant only by preserving uniform conditions of inductancein the alternating current circuit, and uniform conditions in the alternator.
The inductancedrop is proportional to the frequency.
Section CD of the rod is used therefore simply to shunt the inductance of winding H to high frequency lightning discharges, leaving the lightning discharge path in the arrester a non-inductive highly efficient path.
Another cause which may be mentioned is the inductance of the armature winding, which is in turn due to the positions of the armature coils with respect to each other and also with respect to the field magnets.
The inductance of a complete single phase circuit = L × 2 ÷ √3.
L = inductance of a loop of a three phase circuit in henrys.
The number of cycles per second, or the frequency, has a direct effect upon the inductance reactance in an alternating current circuit, as is plainly seen from the formula.
This means that the best conditions exist when the resistance is low and the inductance large.
In furnishing a plurality of operators' transmitters from a common battery, the importance of low resistance and inductance in the portion of the path that is common to all of the circuits must not be overlooked.
It is well to have the inductance of this shunt made adjustable by providing a movable iron core for the shunt winding.
When the core is drawn out of the coil, its impedance is diminished because the inductance is diminished.
The capacity of a condenser, inductance coil or other device capable of retaining a charge of electricity.
A wiring diagram of a multipoint inductance coil is shown in Fig.
An aerial and ground wire and that part of the inductance coil which connects them.
When two oscillation circuits are connected together either by the magnetic field of an inductance coil, or by the electrostatic field of a condenser.
When a circuit has inductance and the current changes in value, it is opposed by the voltage induced by the variation of the current.
A tuning device for varying the inductance of the receiving oscillation circuits.
By windinginductance coils with two or more layers the highest inductance values can be obtained with the least resistance.
But if you vary the inductance of the one loop so that it is larger or smaller than that of the other loop no spark will take place in the second circuit.
Now theinductance and resistance of a circuit such as is shown at A in Fig.
The simplest kind is a transmitting inductance which consists of 25 or 30 turns of copper wire wound on an insulating tube or frame.
Where wave lengths of more than 2,200 meters are to be received coto-coils are used as these are the "last word" in inductance coil design, and are especially adapted for medium as well as long wave lengths.
Inductance is that property of an oscillation circuit that makes an electric current take time to start and time to stop.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "inductance" in a variety of sentences. We hope that you will now be able to make sentences using this word.
