. A text book of physics, for the use of students of science and engineering . ?-> -X -4- i !? 986 3i le wound field FIG. 037.—Shunt wound field magnet. forms, one form being that given in Fig. 036. Here the currentflowing in the field coils, which causes the magnetisation, flows alsoin I he external circuit. The field coils are thus in series with thearmature and the external circuit. When this arrangement isadopted the dynamo is said to be • series wound. Series winding hasthis advantage, thai as the current in the external circuit increases, Lxxvn CHARACTERISTIC OF A DYNAMO 995
. A text book of physics, for the use of students of science and engineering . ?-> -X -4- i !? 986 3i le wound field FIG. 037.—Shunt wound field magnet. forms, one form being that given in Fig. 036. Here the currentflowing in the field coils, which causes the magnetisation, flows alsoin I he external circuit. The field coils are thus in series with thearmature and the external circuit. When this arrangement isadopted the dynamo is said to be • series wound. Series winding hasthis advantage, thai as the current in the external circuit increases, Lxxvn CHARACTERISTIC OF A DYNAMO 995 the magnetisation of the field magnets is thereby increased. Thereis usually enough residual magnetisation in the iron cores of thefield magnets to produce a feeble current when the machine starts,provided that the external circuit is closed. The voltage andcurrent then mount up rapidly as the magnetisation series winding consists of few turns of low resistance, sincethe resistance of the coils is included in the internal resistance ofthe machine. In Fig. 937 the field coils consist of a great many turns
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishe, booksubjectphysics
