Switch

“ A switch is a piece of apparatus for making, breaking, or changing the connections in an electric circuit.
The particular form and construction of any switch is governed by the electrical conditions under which it must operate.
Since the electric current cannot be stopped instantly when the circuit in which it is flowing, is broken, an arc is formed as the switch contacts separate; this tends to burn the contacts, and to short circuit, the severity of such action depending on the voltage and the proximity of the switch terminals. ”

“ The man learns to look at the switch as he comes up the stairs, after preparing the furnace fire for the night, and learns to take hold of the switch when he sees it and turn off the light. Coming up the stairs means to look at the switch. ”

“ It furnishes many similes of graphic helpfulness in understanding more nearly much truth of the Spirit life.
In the power-house where the electricity is being wooed into man's harnessing, or generated, as the experts say, is found a switchboard, or switch-room with a number of boards. Here in a large city plant a man may go and turn a switch, that is, move a little handle, a very short distance. ”

“ She moved now to an electric-light switch, and turned on the light. They must be able to see beyond any question of doubt that the person escaping through the window was not the Sparrow. What was she afraid of now, just at the last! ”

“ From long training the despatchers become perfectly familiar with every detail of the sections of road under their control, the position of every switch, each station, all curves, bridges, grades, and crossings. ”

“ A reversing switch is provided, so that the truck can travel in either direction, and when the machine has reached its stopping point, either forward or backward, it is checked by an automatic cut-off. ”

“ I have often watched the means it employed to obtain any small object that happened to be a little beyond its reach; if it could lay its hands upon a little switch, or slender twig of any sort, it would stretch itself out as far as its cord would allow, and continue working at the object till it got it within its reach. ”

“ A reversing switch is needed to alter the direction of the current flow. The construction of one is an exceedingly simple matter. Fig. 48 gives a plan of switch and connection, from which the principle of the apparatus will be gathered. The two links, LL, are thin springy brass strips slightly curved, and at the rear end pivoted on the binding posts T1 T2. Underneath the other ends solder the heads of a couple of brass nails. The links are held parallel to one another by a wooden yoke, from the centre of which projects a handle. ”

“ A characteristic advantage of the constant current system is the extreme simplicity and cheapness of the switching arrangements as compared with the complication and cost of the ordinary switch-board for a poly phase station at high voltage. ”

“ The wiring diagram is shown in fig. 2,670.
The switch when on a large system is often in a cell some distance behind the panel, and is then controlled by a system of levers, or by a small motor which is started and stopped by a throw over switch on the panel, in which case there is generally a lamp or lamps on the panel to show whether the switch is open or closed. ”

“ The switch arm, to which the handle is attached below, does not itself make and break the circuit, but carries a spring, as shown, which, when the arm is at the end of its movement, pulls over the contact lever with a rapid action, shooting the same between the divided contact piece, and making a perfect contact. The switchboard forms one side of a closed wooden case or cupboard, with sufficient room for a man to enter and adjust the resistances or switches for each lamp. ”

“ If you could only forget that there are thousands of circuits here, you would understand it very readily. It is the repetitions that make it seem so complicated, Now, this switchboard is divided into two parts. We call one the ‘A’ board, it takes up about two thirds of the room; and the other is the ‘B’ board. Suppose you were a subscriber connected with this central, and wished to call up some one also connected with this central. ”

“ The metallic circuit is used for talking and for ringing the called subscriber's bell, while ground return circuits, on one side of the line or the other, are used for sending all the switch controlling impulses. ”

“ If the starting switch do not have to carry the full load current and can be short circuited by another switch, a starting switch of smaller capacity equivalent to 50 per cent of running current of the machine can be used. ”

“ A direct control switchboard has all its apparatus mounted directly on the board and controlled by hand, while in the remote control type, the main current carrying parts are at some distance from the operating board, the control being effected by mechanical devices or by electric motors or solenoids. When the control system of a plant is very extensive, it sometimes occupies a separate building known as the switch house. ”

“ Machine-Switching System.—A retrospective examination of the manually operated switchboard discloses the fact that the tendency of development has been continuously in the direction of increasing the number and extent of the operating functions which are performed electro-mechanically and likewise decreasing the amount of time required of the operator for the handling of the connexion. ”

“ By the aid of this apparatus and its distant signals, connected by wire ropes, the switchman's anxieties are reduced immeasurably. By concentrating the levers of a number of switches in a single room one man can do the work of several, and to the looker-on the perplexities of the position seem to have been increased instead of diminished. ”

“ And yet an honest man of that type is the kind demanded for such a place. The interlocking of switches and signals (the arrangement in a frame of the levers moving the switches and those moving signals in such a way that the signal which tells the engineer to come on cannot be given until the switch is actually in proper position) is one of the notable improvements of the last twenty years, and is a great boon to switchmen, as well as to passengers and the owners of railroads. ”

“ The training of a switchman is usually such that, if let alone, he will stick the car in the first convenient track and wait to make a delivery until he can pull every track in the yard and put with it all other cars with the same cards or marks. ”

“ The aerial switch is necessary for quickly connecting the aerial and ground to either the transmitting or receiving apparatus. Amateurs very often employ a small "double pole double throw" switch. The switch used in commercial stations is built in the manner shown in Fig. ”

“ In that way I learned a great deal about the arrangement and construction of switchboards. Encountering the trouble first, I had an advantage over others in being able to suggest a remedy. So I have always thought it was a good thing to have troubles, as long as they are not too serious or too numerous. Troubles are certainly a great advantage, if we manage them correctly.
Certainly Carty made these switchboard troubles the first stepping-stone in his climb to the top in the field of telephone engineering. ”

“ The running down of the calling device in conjunction with the operation of the exchange switches controls the action of the latter by means of an electrical circuit established through the setting of the levers so that the exchange switches are made to trunk, hunt and find lines in a manner corresponding to the lever setting. The mechanism at the exchange is driven by a motor and can therefore be provided with robust contacts. ”

“ The line connects the levers together perpendicularly. The springs being connected horizontally, form the connecting bars. Any two circuits are connected by throwing the corresponding levers on the same row of springs. We have testimonials from parties using the switch, where one operator does all the work satisfactorily for three hundred subscribers, where with any other system it would require at least two, thus making a permanent saving in the running expenses. A cheaper type of Snell switchboard is shown in Fig. ”

“ And besides this, safety is further promoted by a series of small signal-discs, which start up before the switchman's eyes at the right moment, and give him demonstration that he has given the right pull at the right handle. ”

“ If the yard doesn’t have switches that work by electricity, switchmen work them by hand. A switchman is sometimes called a cherry picker, because of the red lights on the switches. Another nickname for him is snake. ”

“ Close S. P. reverse current circuit-breaker
{ and switch No. 2 to the left (casemate
{ generator) .
2o Read voltage by plugging in proper receptacle.
3o Close switch No. 3 up.
4o " " " 4 " (or down) .
5o " " " 9 " ( " " ) .
6o Read A. C. voltage by plugging in proper receptacle.
8o Close switch No. 8 up.
Q. Explain how to set operating panel for automatic firing.
A. All contacts, connections, switches, etc., having been previously tested and examined by the electrician and found in order:
1o Close up the testing, automatic, mine, power, and gong switches. ”

“ A constant shifting of switches is going on, and the little shunting engines never stand still. The switches, however, as a rule, are unprovided with signals, except of the crudest description; they have no connection with each other, and during thirty years no change has been made in the method in which they are worked. ”

“ The other thing of which the network is constituted is switches. Switches are what determine who gets what, where, when, how and how much they pay for it. Switches are the things which determine which signals in the net go where, and why. Switches are computers, and they run by code, and, as my dear friend and colleague Larry Lessig pointed out in his first brilliant book “Code”, they are capable of imitating law, because they create reality. They determine who gets what, and in determining who gets what and at what price they determine access to knowledge and therefore power. ”

“ The signaling is done by pressing and releasing a knob the requisite number of times. . . . On June 12, 1879, the parent Bell company sent out photographs and a circular describing 'our No. 1 standard central office strip switch arranged for seventy-five circuits.'
In November, 1881, Mr. ”

“ Life 'goes out,' like a lamp when the materials supplying the electric current are exhausted; and yet here all the waste of which physic can take cognisance is fully repaired, and the circuit is not broken. ”

“ It is sufficient for the moment to show the essential relations in the circuit without any attempt to differentiate the various images produced. The circuit starts in the mind of one person, passes exteriorally, and enters the mind of the other. ”

“ I have a thought about a wire which shall reach round the earth and oversea and undersea, on which a man may send a message. And a thought I have about a wire which shall stretch across the land, and upon that wire a voice may travel alone. ”

“ When the circuit is closed there is a bubbling, murmurous sound in the ears, a warm sensation where the wires touch the cranium, and a feeling as of a motion through the brain, entering at one point and going out at another. ”

“ In certain of its phenomena, now classified as electrical, this dual impulse is noted and its action is called “closing the circuit” and “breaking the circuit.” This same dual impulse or tendency to embrace and separate—embrace and separate—obtains throughout the entire cosmos, proving the universality of electrical action. Ether, fire, air, water, earth, sound, sensation, light, form, color, smell, food, thought are all known to be modes of motion—rates of vibration. Motion of what? Rate of vibration of what?—Of the infinite, integral, component electrons of the one universal substance. ”

“ In each circuit are five lamps through which the current belonging to the circuit passes in succession. The lights correspond to so many resisting spaces, over which, as already explained, the current has to leap; the force which accomplishes the leap being that which produces the light. Whether the current is to be competent to pass through five lamps in succession, or to sustain only a single lamp, depends entirely upon the will and skill of the maker of the machine. ”

“ If we have a house with one bell, and ten wires each fastened to a door running to the center, all having wire connection and so arranged that to pull any one wire will set the bell in motion, and without an indicator you cannot tell which wire is disturbed, producing the effect or ringing of the bell at the center. ”

“ By the objective circuits we mean those circuits which are established between the self and some external object: mother, father, sister, cat, dog, bird, or even tree or plant, or even further still, some particular place, some particular inanimate object, a knife or a chair or a cap or a doll or a wooden horse. For we must insist that every [187] object which really enters effectively into our lives does so by direct connection. ”

“ With another instrument we can go further, and exchange thoughts, in a few seconds, with a being on the other side of the world, by means of a thin wire that is itself fixed, and does not move, and we have lately invented another means by which we can do the same, over several thousands of miles, without even a connecting wire. ”

“ Let the most vigorous of human imaginations but attempt to take a single step toward the comprehension of a circuit so unutterable! I would scarcely be paradoxical to say that a flash of lightning itself, travelling forever upon the circumference of this inconceivable circle, would still forever be travelling in a straight line. ”