Thus if such a lamp is connected with an alternating current circuit, it lets through the current in one direction and stops that in the other, thus furnishing a current which is always in one direction.
The plate CD is connected with an alternating current dynamo, which produces a simply-periodic potential difference between AB and CD, the other pole being put to earth.
Illustration: Fig 54] When the key in the plate circuit of the audion at the sending station is depressed an alternating current is started.
Illustration: Fig 34] And now we can see how to make an audion produce an alternating current or as we sometimes say "make an audion oscillator.
This induces an alternating current in the neighboring antenna circuit.
When an alternating current of any frequency passes between them a sheath of violet light forms on one of the electrodes, passing over to the other when the current reverses during each cycle.
This form is known as alternating current, as opposed to direct current, in which there is no changing of positive and negative.
Direct current may be changed to alternating by having a direct current motor running an alternating current dynamo, or the change may be made by a rotary converter, although this last method is not so satisfactory as the first.
Now suppose that at this instant, corresponding to the beginning of an alternating current cycle, a second current b, differing in phase from the first by 90 degrees, is allowed to enter the ring at C.
In alternating current circuits a precisely similar action takes place between the alternators and synchronous motors, or even between the alternators themselves.
Since an alternating current cannot be used for exciting the field-magnet, recourse must be had to some source of a direct current.
There are numerous types of electric motor as of the dynamo in use, but they are all modifications of the simple continuous or alternating current dynamo.
By repeatedly making and breaking the circuit in the primary coil we get an alternating current in the secondary coil.
The work done in lifting the telephone receiver a distance of one foot, if changed into an alternating current, would be sufficient to keep up a sound in the receiver for a hundred thousand years.
Since the field in the transmitter is made alternately stronger and weaker, the current in the coil flows first in one direction, then in the opposite direction--that is, we have an alternating current.
Thus far I have applied the repulsive action described in the construction of alternating current indicators, alternating current arc lamps, regulating devices for alternating currents, and to rotary motors for such currents.
CC' are the field coils or inducing coils, which alone are put into the alternating current circuit.
The primary circuit taken from the alternating current mains by the cord B, embraces the primary winding of the transformer T, a condenser C, and the coils P, of the vibrating units, fig.
With a direct current on the line, a direct current dynamo may be used; but with analternating current an induction motor is required.
It depends on the following points: First, the impedance[1] of the coils keeps the exciting current which they take from the collector rings down to a small value as it is alternating current.
Where current has to be conveyed economically over long distances, it is generally done in the form ofalternating current at high pressure.
After much theoretical and experimental work, they found it in the single-phase system, using a motor which is similar in many respects to the continuous-current motor but capable of being operated by alternating current.
The 'hum' of an alternating current cannot be altogether eliminated, but can be reduced to a minimum by reducing the voltage as far as possible.
So far," said Tesla of his power plant where the first attempts at wireless transmission are being made, "only about three million horsepower has been harnessed by my system of alternating current transmission.
Indeed, more than four million horsepower of waterfalls are harnessed by Tesla's alternating current system.
It may be attached to any electric light socket of 110 volts direct or alternating current.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "alternating current" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
