Light switch

“ Various sizes are of course made, from a small switch to turn on one light to others to turn on say all the lights in a room, and large main switches which are used below in the engine-room for turning on as many as 500 lights. ”

“ From the diagram it is seen that the light may be controlled from either switch. It is a bad arrangement to have travellers and return wire located near each other, as it is possible by this method to connect two individual circuits together and possibly overload one of the two feed wires of each circuit. However, should each feed wire run to a fuse direct, without any other lamps than those contained in the three way circuit being connected, it is not objectionable and becomes a convenient method in many cases. ”

“ For these lamps there is provided a new style of holder, which is at once simple and efficient. Each lamp has its own switch, which is entirely of metal; and it is provided with a lead-wire, which fuses in the event of the current being too strong. In the case of every set of about twenty lamps there is another switch, so that the lights can be turned on and off in groups as well as individually; and another lead-wire, so that the leading wires may be protected from too strong a current. The whole system is such as to preclude the possibility of fire. ”

“ The undulation of the current is almost essential to the commercial success of an arc-light system. It introduces in the circuit a steadying element taking the place of a large ohmic resistance, without involving a great loss in power, and, what is more important, it allows the use of simple clutch lamps, which with a current of a certain number of impulses per second, best suitable for each particular lamp, will, if properly attended to, regulate even better than the finest clock-work lamps. ”

“ Constant-potential lamps cannot be operated without resistance in the circuit; this resistance may be in the lamp itself or outside.
(6) Never handle high tension lamps without insulating yourself from the ground; and handle live wires only with one hand at a time.
(7) Provide spark arresters for all open-arc lamps in the vicinity of inflammable material.
(8) Never leave a lamp without globes where the wind can strike it. It will be blown out or feed often, thus consuming the electrodes very fast and at the same time yielding a very poor light. ”

“ This is called the multiple circuit, and it is obvious that the entire amperage produced by the dynamo will not be required to pass through each lamp, but, on the other hand, each lamp takes only enough necessary to render the filament incandescent.
This invention at once solved the problem of the incandescent system and was called the subdivision of the electric light. By this means the cost was materially reduced, and the wiring up and installation of lights materially simplified. ”

“ Lamps may be connected in parallel and each turned on or off by means of a hand-operated switch or the button on the lamp socket, or if desired a hand-operated adjustable resistance may be included in the circuit of each lamp for gradually causing the object to fade away or reappear slowly. ”

“ A difference of a few lamps, affecting the engine to a small extent only, should be compensated automatically by the governor. If the brightest lamps are not bright enough, the speed should be increased a little, but care must be taken not to overdo it, because if the current is too strong, some of the safety fuses will melt, and the corresponding lamps will go out. It must not be inferred from what I have said, that it is necessary to run the dynamo at first without switching on any lamps. Turn all lamps on, and light up gradually. ”

“ In that class of lamps where the regulation of the arc is effected by forces acting in opposition on a free, movable rod or lever directly connected with the electrode, all or some of the forces being dependent on the strength of the current, any change in the electrical condition of the circuit causes a vibration and a corresponding flicker in the light. ”

“ You must remember, to begin with, that in referring to wire used on magnets and armatures and for carrying the electricity away to the lamps, we always mean wire that is covered or insulated. In electric lighting, insulated wire is always used, except at the points where it is connected with, the dynamo, the lamps, a switch, or any point where we make what is called a "connection." ”

“ A perfected lamp would require but little energy, and if wires were used at all we ought to be able to supply that energy without a return wire. It is now a fact that a body may be rendered incandescent or phosphorescent by bringing it either in single contact or merely in the vicinity of a source of electric impulses of the proper character, and that in this manner a quantity of light sufficient to afford a practical illuminant may be produced. ”

“ The difficulty of operating a lamp on the alternating current circuit lies in the fact that while a current will flow freely through it in one direction, when the current reverses the negative electrode or cathode acts as an electric valve and stops the current, thus breaking the circuit and putting out the light. ”

“ The high-frequency currents also bring us to the realization of a more economical system of lighting; namely by means of phosphorescent bulbs or tubes, and enable us to produce with these appliances light of practically any candle-power. Following other developments in purely electrical lines, we have all rejoiced in observing the rapid strides made, which, in quite recent years, have been beyond our most sanguine expectations. ”

“ A lamp S is connected in parallel with a coil of fairly fine wire having a removable iron core, and the terminals T, T' connected to a source of direct current, a switch M being provided to interrupt the current. The voltage of the current and resistance of the coil are of such values that when a steady current is flowing, the lamp filament is just perceptibly red. At the instant of making the circuit, the lamp will momentarily glow more brightly than when the current is steady; on breaking the circuit the lamp will momentarily flash with great brightness. ”

“ To use a lower voltage or pressure, while making the solution of the lighting problem a simple one as we shall see, would make it necessary to increase the size of the conducting wires to a prohibitive extent. To increase the voltage or pressure materially, while permitting some saving in the cost of conductors, would enormously increase the difficulties of making a sufficiently high resistance conductor to secure light by incandescence. ”

“ An incandescent lamp, mounted on a powerful coil, is lit without contact by ether waves transmitted from a cable running round the laboratory, or bulbs and tubes containing highly rarefied gases are placed between two large plate-terminals arranged on the end walls. As soon as the bulbs are held in the path of the currents passing through the ether from plate to plate they become incandescent, shining with a light which, though weak, is sufficiently strong to take photographs by with a long exposure. ”

“ On a 110 volt system two ordinary lamps are connected in series, while the line connecting the lamps is connected to the ground through a snap switch S. When current is on, the two lamps will burn with equal brilliancy, but at a lower candle power. When the switch S is closed, if the two lines be clear, the brilliancy of the lamps will not be affected, but if there be a ground on the positive side, one lamp will burn brighter, the brightness depending on the resistance of the ground. If there be a dead ground, the lamp will burn to its full candle power. ”

“ The currents from those points are conducted to the lamp-table, and thence through the traversing platform to the lamps, metallic contact being obtained throughout the whole circuit by means of flat springs moving over flat surfaces. The changing of the lamps is effected, without any appreciable break of continuity in the light, by means of the traversing platform on which they stand, and which has a sliding motion from side to side. When the carbon-points in one lamp are nearly consumed, the traverser is quickly shifted from right to left, or vice versa, as may be necessary. ”

“ It was evolved from the early observed fact that a conductor is heated when traversed by an electric current, and that if it has a high resistance and a high melting-point it may be rendered incandescent, and therefore become a source of light. Naturally every inventor turned his attention to the employment of wires of refractory metals, such as platinum or alloys of platinum-iridium, &c., for the purpose of making an incandescent lamp. ”

“ It blinked red at him as he stood on the track facing it; the green rays were shooting up and down the line. He couldn't swing the switch—but the lamp was there—and there was the red side to show just by turning it. He remembered then that the lamp fitted into a socket at the top of the switch stand, and could be lifted off—if he could reach it!
It wasn't very high—for an ordinary-sized man—for an ordinary-sized man had to get at it to trim and fill it daily—only Toddles wasn't an ordinary-sized man. It was just nine or ten feet above the rails—just a standard siding switch. ”

“ To exhibit this mysterious effect we bring the ends of the electrical current which we wish to excite near each other, but not touching, in a glass tube with thin walls, from which the air has been exhausted. When the X rays fall on the gap between the wires the electrical current immediately jumps across the gap with a vivid light. ”

“ The second form of illumination is what is known as the 'incandescent system,' and consists generally in the passage of a current of electricity through a continuous strip or piece of refractory material, which is a conductor of electricity, but a poor conductor; in other words, a conductor offering a considerable resistance to the flow of the current through it. It was discovered early in this century that various substances might be heated to a white heat by passing a sufficiently strong current of electricity through them. ”

“ A thought which naturally presents itself in connection with high frequency currents, is to make use of their powerful electrodynamic inductive action to produce light effects in a sealed glass globe. The leading-in wire is one of the defects of the present incandescent lamp, and if no other improvement were made, that imperfection at least should be done away with. ”

“ On passenger steamers, side one blaze of light, and side lights barely visible. but many who have seen a large passenger steamer go past will have noticed how her side was—one, [43] two, or three rows of dazzling bright lights, and will have looked almost in vain for the green or red light dimly visible in the midst of all the bright ones. If bright electric lights, therefore, are shining through the ports, we must have our side lights at least as bright, so as to give them a chance of being seen. If electric lamps are used as side lights, the dynamo must be kept running all night. ”

“ If one lamp went out through the filament giving way, it would not affect the others, so that there would still be a light in the lantern. If, through some breakdown of the engine or dynamo, the electric current were no longer to be had, then it [42] Mast-head light. would only be necessary to withdraw the stand of lamps, and put in the ordinary regulation oil-lamp. The mast-head lamp could also be fitted with the electric light, as indeed has already been done. Arc light should never be used. ”

“ Enclosed arc lamps are made to burn without attention for 200 hours, singly on 100 volt circuits, or two in series on 200 volt circuits, and in addition to the cost of carbons per hour being only about one-twentieth of that of the open arc, they have another advantage in the fact that there is a more uniform distribution of light on the road surface, because a greater proportion of light is thrown out horizontally. ”

“ In the incandescent light the electricity has as many paths as there are lamps, so we only need to keep one certain pressure in volts in the main wires all the time. This pressure is even all the way through the main wires, and, therefore, it is ready to light a lamp the instant it is turned on, because, as you have seen, electricity will always get back to the dynamo if there is a possible chance, and the lamp opens a path. ”

“ Lamps through whose
regulating mechanism the whole current passes. These are only adapted to
work singly; if several are placed in series on the same circuit, the
action of one regulator interferes with that of the next one.
(b) Multiple light regulators or polyphotes. In these the regulating
mechanism and the carbons with their arc are in parallel; the regulating
device may be a single magnet or solenoid constituting a derived or
shunt-circuit lamp, or it may include two magnets working differentially
against or in opposition to each other constituting a differential lamp. ”

“ No time will be lost in putting this announcement to the test, not only of scientific but also of practical verification, and the probability is that all electric lighting stations in the twentieth century will contain not only dynamos of one type for the supply of light, but also direct current generators for transmitting power in all directions over the same cables. ”

“ The light is not actually transmitted, but only its effects. Suppose a picture is laid off into small squares and there is a selenium cell corresponding to each square and for each selenium cell there is a wire that runs to a distant station in which circuit there is a battery. At the distant station there are little shutters, one for each wire, that are controlled by the electric current and so adjusted that when the cell at the transmitting-end is in the dark the shutter will be closed. ”