. Electrical world. complete lines of data through the testing of some forty designs ofmagnets on a testing machine constructed for this special Figs 3 and 4 are shown the magnetic cushion type of electro-magnet designed to overcome the objections to the employment ofthe usual type for lifting and other purposes. The initial pull ofthe magnet through the air gaps encountered in common practiceis fully equal to that of a plugged or stopped type of magnet of and protected by the ironclad construction of the return magneticcircuit. Fig. 5 shows a gravity type of magnetic switch, made i
. Electrical world. complete lines of data through the testing of some forty designs ofmagnets on a testing machine constructed for this special Figs 3 and 4 are shown the magnetic cushion type of electro-magnet designed to overcome the objections to the employment ofthe usual type for lifting and other purposes. The initial pull ofthe magnet through the air gaps encountered in common practiceis fully equal to that of a plugged or stopped type of magnet of and protected by the ironclad construction of the return magneticcircuit. Fig. 5 shows a gravity type of magnetic switch, made in capacitiesfrom I to 150 amperes. In opening an electric switch circuit carry-ing a heavy current the switching device employed should meet thefollowing requirements: First, it should open instantaneously; sec-ond, its contacts should be protected by a powerful magnetic blow-out,and third, in opening, its contacts should invariably be separated tosuch an extent that the magnetic blow-out will be instantly effective. FIG. 3.—CROSS-SECTION VIEW OF ELECTROMAGNET. equal weight, and a most desirable characteristic is obtained, in thatthe curve of tractive force is almost a horizontal line, which obvi-ates rapid acceleration of the plunger toward the end of the motion of the plunger is arrested simply by the action of the
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectri, bookyear1883
