Transactions

574 TRANSACTIONS OF THE A.S.M.E. OCTOBER, 1941th e effective to o th area is th u sWithin the active length, tooth and conductor are connectedin parallel. Outside this length the conductor has an impedanceof Ar, — j Ax, and the effective impedance of one slot pitch isthusD i f f e r e n t i a l E q u a t io n s a n d T h e i r S o l u t io nThe sum of the currents I h under the pole arc produces a fluxof 2i in the interpolar space, i.e.F ig . 9D is t r ib u t io n o f P u l s a t in g F ie l dm, and is estimated according to previous investigations whichshow that for / cycles per sec and 50 cycles per secwhere the factor y and the inductance lk are determined by fieldplotting, as shown in Fig. 10.The a-c permeability in general will be rather high, especiallysince, at higher frequencies (see Fig. 9) is divided into „ alongthe pole-shoe surface and *along the short-circuit winding. Inview of this, the ampere turns consumed for the iron will beneglected.The fact that the teeth lead currents parallel to the cagewinding must, however, be taken into account since this willlessen its effective resistance and also influence its leakagereactance. The cage winding is not insulated. To a currentdensity S in the conductor there corresponds a current density