Spark gap

“ Caution.—The current should never be allowed to pass over the safety spark gap for any length of time, and if the engine is operated on a second or auxiliary ignition system, the magneto must be grounded in order to prevent the production of high tension current. The snapping sound by which the passage of current across the safety spark gap may be noted should always lead to an immediate search for the cause of the difficulty. ”

“ When the spark gap is placed at O, the principal focus of P, the rays emerge parallel into the air film, and are then focussed by the second cylinder at an equal distance ƒ on the other side.
The spark gap is placed at O, and the receiver at O ́, OO ́ being extremities of a diameter passing through the centre of the circle. The air film is for convenience placed parallel to the index. ”

“ If to the spark balls the secondary terminals of an ordinary induction coil are connected, and these spark balls are adjusted near one another, then when the ordinary coil is set in operation, sparks pass between the balls and oscillatory discharges take place in the circuit containing the spark gap. ”

“ GAP, FIXED.--One with fixed electrodes.
GAP, NON-SYNCHRONOUS.--A rotary spark gap run by a separate motor which may be widely different from that of the speed of the alternator.
GAP, QUENCHED.-- (1) A spark gap for the impulse production of oscillating currents. (2) This method can be likened to one where a spring is struck a single sharp blow and then continues to set up vibrations. ”

“ In such a case, however, it is an advantage to employ a spark-gap in compressed air, because we can then raise the voltage to a much higher value than in air of ordinary pressure without lengthening the spark so much as to render it non-oscillatory. ”

“ If, with an apparently good spark, you have compression and there is mixture passing into the cylinders, the trouble may be in the spark plug. To test a spark plug it is necessary to remove it. Widen the gap to 1⁄8 inch and lay the plug with wire attached upon the cylinder; crank the engine and see if a spark jumps the gap. Widening the gap is necessary because the spark will not jump so far under compression as in the open air. If it does not jump, the plug may have a broken insulator porcelain or need cleaning. ”

“ The quenched gap radiates considerably more energy than any other form of gap and also has the advantage of being practically noiseless. The crashing discharge of an ordinary gap produces a very disagreeable penetrating noise hard to eliminate. In most commercial stations the spark is muffled to a certain extent by enclosing it in a cylinder of micanite or some other insulating substance. ”

“ By widening the gap in the plugs the secondary current is held back until it acquires high enough potentiality to jump the greater118 gap; so that when it does occur an exceptionally powerful spark is obtained. ”

“ A high tension spark occurs at each contact of the roller with the sectors, as the contact allows current to flow through the primary of the coils. The high tension 238binding posts S1-S2-S3-S4 are connected with the spark plugs or spark gaps U1-U2-U3-U4 by means of high tension cables. As soon as the timer grounds a coil, the coil produces a high tension spark in its corresponding spark plug. ”

“ If A and B approach to touch each other, the spark is stronger, because the difference between them is greater: After such touch there is no spark between either of them and C, because the electrical fire in all is reduced to the original equality. If they touch while electrising, the equality is never destroy'd, the fire only circulating. ”

“ The consequence is, spark follows spark till the equilibrium is restored. Touch the top first, and on approaching the bottom, with the other end, you have a constant stream of fire from the wire entering the bottle. Touch the top and bottom together, and the equilibrium will instantly be restored, the crooked wire forming the communication. ”

“ But there is one Spark in this world—a grand, glowing, gushing fellow—who has not his equal anywhere. He is old as the hills—perhaps older—and wide as the world—perchance wider. Similar to ordinary sparks in some respects, he differs from them in several important particulars. ”

“ The spark, having taken a new direction, must now act on, or most strongly repel the column of air which lies in that direction, and consequently must condense that column in the same manner as the former, when the spark must again change its course, which course will be thus repeatedly changed, till the spark reaches the body that attracted it. ”

“ Amid the sparking cloud of fireflies, fluttering cornflakes, glinting spoons, and a foursome of hazy, still-processing new labs, there was a newcomer to the chaos. Something in one of the plunging artifacts must have rubbed something else the wrong way, made a spark, and—Well, the machine was complacently sucking in raw blazing energy, now, tongue upon tongue of orange flame and black, spiralling smoke that rose from the pyre of shattered synthetics. ”

“ I began to crank, praying steadily for a miracle. Now and then I managed to coax forth a gaseous chortle or two. The convention on the landing understood every chortle in a truly marvellous way.
"It's the spark-plug, that's sure!" announced one with an air of finality. "When an engine has run for a while (!) the spark-plug gets all smutted up. Have you cleaned your spark-plug?" ”

“ Now let the globe be turned, and you see a spark strike from the bullet to the wire of the bottle, and the same instant you see and feel an exactly equal spark striking from the coating on your knuckle, and so on spark for spark. ”

“ It is not unlikely that sparks occasionally struck out from flint when it was being chipped into shape for a weapon or implement. Necessity and desire have always worked wonders, and primitive man learned shortly to produce the vital spark, both by friction and by drilling. ”

“ I take the steel and the flint, and striking them together I get sparks. I want you to ask yourselves, Where do the sparks come from? Each spark is due to a minute piece of iron being knocked off the steel by the blow of flint with steel. Note the precise character of the spark. Let me sprinkle some iron filings into this large gas flame. You will notice that the sparks of burning iron filings are very similar in appearance to the spark I produce by the collision of my flint and steel. ”

“ The oscillation produced by a single break is quite sufficient for a single experiment, and it is mere waste to have a series of useless oscillations. But the most serious objection to the production of secondary sparks, unless absolutely wanted, is their deteriorating action on the spark balls. Anyone who has tried to obtain an oscillatory discharge knows how easily the discharge becomes irregular, and the most fruitful source of trouble is often traced to the disintegration of the sparking surface. ”

“ The point of present interest is the cohesion which sets in between the knobs when the spark occurs: an extremely feeble spark was found sufficient to produce the effect, provided the surfaces were already almost infinitely close together, i.e., provided they were already in what would be called contact, with the merest imperceptible film of (probably) oxide separating them, just the kind of film which a chemical flux is useful in removing. ”

“ We prefer to call him a Spark, because in that form only is he visible—at least when handled by man.
Talking of that, it was not until the last century that master minds found out how to catch and handle our Spark. In all the previous centuries he had been roaming gaily about the world in perfect freedom; sometimes gliding silently to and fro like an angel of light; sometimes leaping forth with frightful energy in the midst of raging tempest, like a destructive demon—ripping, rending, shattering all that attempted to arrest his course. ”

“ This breaking down of the medium occurs principally when the force acting between the bodies is steady, or varies at a moderate rate. Were the variation sufficiently rapid, such a destructive break would not occur, no matter how great the force, for all the energy would be spent in radiation, convection and mechanical and chemical action. Thus the spark length, or greatest distance which a spark will jump between the electrified bodies is the smaller, the greater the variation or time rate of change. ”

“ The spark made by a flint and steel, consists of a thin shaving of steel, scraped off by the flint and heated by the arrested motion. When well struck, the spark is white-hot and at that temperature it burns with bright scintillations in the air, just as iron that is merely red-hot burns in pure oxygen. ”

“ Every time he brings his finger near the cylinder, he draws a spark like that received by the exciter. Emboldened by his example, the spectators draw near and evoke the electric explosion. They crowd around the wonderful cylinder that now contains the fire from heaven, called down by man’s genius; each one wishes to call forth the lightning, and each wishes to see sparkle between his fingers the fulminant substance descended from the clouds. So they play with the thunder for half an hour with impunity, when all at once a violent spark reaches de Romas and almost knocks him over. ”

“ A secondary distributer will give trouble through loose contacts, dirt, or the splitting of the spark, the effect of the last being the passing of the spark from the revolving part to two or more contact points instead of but one. Particles from the carbon brush in wearing off may stick to the insulating ring between the contacts and form a path, or a strand of wire may project, producing the same result. ”

“ Martin to Trouble. “He means a spark arrester would stop the sparks from flying from the stacks. Arrest means to stop, you know.”
“How do they stop the sparks,” asked Ted.
“Generally they put a piece of wire netting over the top of the chimney or smokestack,” his mother answered. “The smoke can go through the netting, but the sparks can’t. It is the big, red hot sparks, flying from the stack, that do the damage. In most locomotives there are these spark arresters of iron or wire netting.”
“I never saw any,” Janet said. ”

“ A puff of wind down the chimney will send a spark into it, and then comes an explosion. It’s something like that when you educated and clever gentlemen begin to bring your fire near the hot inflammable minds of our ignorant lads. You don’t mean there to be any spark; you mean to get your material well dried and in good working order, so that it can be used for right and legitimate ends ”

“ Many a brilliant spark is born where the hammers ply, But a lurking thief is there; prompt, with finger sly, Spark on spark he puts them out, sparks which might have soared Perish underneath his touch. ”

“ It is curious to observe the relation of glow, brush, and spark to each other, as produced by positive or negative surfaces; thus, beginning with spark discharge, it passes into brush much sooner when the surface at which the discharge commences (1484.) is negative, than it does when positive; but proceeding onwards in the order of change, we find that the positive brush passes into glow long before the negative brush does. ”

“ To sum up these considerations respecting the character and condition of the brush, I may state that it is a spark to air; a diffusion of electric force to matter, not by conduction, but disruptive discharge, a dilute spark which, passing to very badly conducting matter, frequently discharges but a small portion of the power stored up in the conductor; for as the air charged reacts on the conductor, whilst the conductor, by loss of electricity, sinks in its force (1435.) ”

“ The hack is a better roadster than the Arab barb. In chemistry, the galvanic stream, slow, but continuous, is equal in power to the electric spark, and is, in our arts, a better agent. So in human action, against the spasm of energy, we offset the continuity of drill. We spread the same amount of force over much time, instead of condensing it into a moment. 'Tis the same ounce of gold here in a ball, and there in a leaf. ”

“ If there is one thing more dangerous than another in the air it is the menace of an open spark close to gasoline feed lines and carburetor mixing chambers.
Knowing it well, unable to determine the cause, but sure that the spark was electrical and dangerous, Bob took the only safe course. As Curt and Al had observed, his engine stopped. He cut off the ignition. ”

“ Already, as they approached, they could hear the dull roar of huge dynamos set in motion to test in preparation for the powerful spark transmission, and as they passed into the power-room, Geoffrey said:
“You’d better hold your fingers in your ears when they try the spark. ”

“ The young people, with a dozen or so of their youthful friends, would join hands, taking, however, care not to complete the circle, and then shuffle their feet vigorously. On completing the circuit, they could produce a combined spark over two inches long, with a correspondingly sharp shock. ”

“ As we do not propose to enter into more than a brief explanation of why and how this apparatus generates current to produce the required spark, perhaps a simple analogy will make matters most intelligible to any reader not well acquainted with electrical phenomena. We know that when a current of electricity is flowing in a wire, and the wire be [Pg 47] suddenly broken, a spark will occur at the point of breakage. ”

“ Such being the rough conclusions reached concerning the duration of the spark upon a grand scale, let us now consider the results of experiment upon it where all the conditions are in command. In 1835, Mr. Wheatstone attempted to measure the spark of a Leyden jar charged by a common frictional machine. The light from the spark was received upon a mirror mounted upon an axle capable of a high rate of revolution. The image of the spark, being thrown upon the mirror, was reflected to a distant point, and the time of the spark was inferred from the fixity or movement of the image. ”