. Electric traction and transmission engineering . Fig. 105. solenoid; in another there is an electromagnetic blow-out;and in another, for use on alternating circuits, there is aseries of gaps between electrodes which will not permitthe maintenance of an arc at normal potentials. Two types of lightning arresters have proved particularlyeffective in the protection of station apparatus, namely thealuminum-cell and the oxide-film arresters. The former 256 TRACTION AND TRANSMISSION. consists of a series of aluminum cup-shaped electrodes uponwhose surfaces are formed films of aluminum hydroxide,imm
. Electric traction and transmission engineering . Fig. 105. solenoid; in another there is an electromagnetic blow-out;and in another, for use on alternating circuits, there is aseries of gaps between electrodes which will not permitthe maintenance of an arc at normal potentials. Two types of lightning arresters have proved particularlyeffective in the protection of station apparatus, namely thealuminum-cell and the oxide-film arresters. The former 256 TRACTION AND TRANSMISSION. consists of a series of aluminum cup-shaped electrodes uponwhose surfaces are formed films of aluminum hydroxide,immersed at short distances from each other in a suitableelectrolyte. The cross section of such an arrester is shownat the left in Fig. 105. It is characterized by the conduc-tion of minute currents at normal voltage and of very largecurrents, without much elevation of temperature, at volt-ages slightly in excess of normal. The number of electrodesor cells depends on the operating voltage, each cell with-standing permanently about 300 volts. To avoi
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Keywords: ., bookcentury1900, bookdecade1920, bookpublisheretcetc, bookyear192
