Theory and calculation of alternating current phenomena . xi-mum at the time ?? = 90°, and the phase of the magnetic fluxthus is ?? = 90°, the flux thus represented by the vector 04> inFig. 18, vertically downward. The generated by this mag-netic flux in the secondary circuit, Ei, lags 90° behind the flux;thus its vector, OEi, passes the zero line, OA 90°, later than themagnetic flux vector, or at the time i? = 180°; that is, the in the secondary by the magnetic flux, OEi, has thephase 7? = 180°. The secondary current, /i, lags behind El, by an angle, di, w
Theory and calculation of alternating current phenomena . xi-mum at the time ?? = 90°, and the phase of the magnetic fluxthus is ?? = 90°, the flux thus represented by the vector 04> inFig. 18, vertically downward. The generated by this mag-netic flux in the secondary circuit, Ei, lags 90° behind the flux;thus its vector, OEi, passes the zero line, OA 90°, later than themagnetic flux vector, or at the time i? = 180°; that is, the in the secondary by the magnetic flux, OEi, has thephase 7? = 180°. The secondary current, /i, lags behind El, by an angle, di, which is determined by the resistanceand inductive reactance of the secondary circuit; that is, by the VECTOR REPRESENT A TION 27 load in the secondary circuit, and is represented in the diagram bythe vector, OF], of phase 180 + du Instead of the secondary current, Ii, we plot, however, thesecondary , Fi = ndi, where ni is the number of secondaryturns, and F\ is given in ampere-turns. This makes us inde-pendent of the ratio of Fig. 18. From the secondary , Ei, we get the flux, $, required toinduce this , from the equation El = \2Tnif^ 10-8;where El = secondary , in effective volts,/ = frequency, in cycles per second,Wi = number of secondary turns, = maximum value of magnetic flux, in lines of magneticforce. The derivation of this equation has been given in a precedingchapter, This magnetic flux, $, is represented by a vector, 0$, 90° inphase, and to produce it a , F, is required, which is de-termined by the magnetic characteristic of the iron and thesection and length of the magnetic circuit of the transformer;this , is in phase with the flux, ^, and is represented by thevector, OF, in effective ampere-turns. The effect of hysteresis, neglected at present, is to shift OFahead of 0#, by an angle, a, the angle of hysteretic lead. (SeeChapter on Hysteresis.) This , F, is the resultant of the secondary , Fi, 28 A
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectelectriccurrentsalte
