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Page:Popular Science Monthly Volume 89.djvu/155

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Popular Science Monthly

��141

��An Electrically Operated Device for Lighting Gas

A SIMPLE and reliable gas-lighting device is shown in the accompany- ing illustration. The gas is ignited by means of an electric spark, produced between the two parts A and B of an electric circuit. The circuit is composed of a source of energy, such as a number of dry cells, a kick-coil, the connecting leads, and a special switch, for the open- ing and closing of the electrical circuit.

The circuit is normally open, but as the lever, controlling the gas valve, is moved or turned from one position to the other, by pulling the chains, the lever C is actuated through a certain arc. Now, as this lever C moves, its upper end passes the projecting point B, which is attached to the upper portion of the burner, and the electric circuit is completed and broken. Just as the point A leaves contact with the point B, an arc is produced. This electric arc is greatly intensified by the electric kick- coil. The two points A and B should be made of platinum, since any other metal will not withstand the extremely high temperature of the arc produced.

Pieces of platinum may be obtained from an old incandescent lamp. The contact piece B is mounted on the brass collar D, by means of a small screw E. The collar D is held in place by the screw F, which draws the two ends firmly together. This collar must be insulated from the fixture or stem by some thin sheets of mica, to prevent a short-circuit. The upper piece of plati- num B, should extend just high enough to reach the lower edge of the gas flame. Now mount an arm C on the valve stem so that it stands in a vertical position when the lever to which the chains are attached is in a horizontal position. Bend this arm into the form shown in the figure, and cut its upper end off so that it is about J/2 in. below the outwardly projecting end of the piece of platinum B. Drill a small hole in the upper end of C and, after inserting a piece of platinum, apply some solder. Then the complete burner and the valve arc mounted on the gas fixture, and from the collar D an insula- ted wire is carried to the point where the battery and the electric kick-coil

��/> CRA5HIN0 SPARK Ofl A/)C 15 fORMCD IN THIS OAP, I6NITING THB OUTFLOMINQ 6/15

���By slowly pulling the left-hand chain, the gas can be electrically lighted

are located. The gas fixture itself forms one side of the circuit, and there- fore one terminal of the battery should be connected to the gaspipe, as depicted.

An electric kick-coil, like the one here used, may be purchased in any electrical establishment, or one may be made by cutting up some iron wire or stove wire and fastening the lengths in a snug bundle, gluing and covering this pack of wire with good stiff writing paper. Then six layers of cotton-covered No. 1 8 gage wire are wound neatly and evenly on top, and of course, each and every layer is insulated from the preced- ing one by sev-eral thicknesses of paper.

At least four dry cells will be required if satisfactory results are desired. Bear in mind that the gas must be escaping from the burner when the arc is formed.

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