42

INVENTIONS OV NIKOLA TESLA.

If transformers be employed, one set of the primary coils, asn n, wound on a ring or annular core is connected to one circuit,as m', and the other primary coils, x n', to the circuit m. Thesecondary coils k k' may then be utilized for running groups ofincandescent lamps p p'.

With this generator an exciter is employed. This consists of

Fig. 33.

MmM-

Ex tiler

ssm

two poles, a a, of steel permanently magnetized, or of iron ex-cited by a battery or other generator of continuous currents, anda cylindrical armature core mounted on a shaft, b, and woundwith two longitudinal coils, o c'. One end of each of these coilsis connected to the collecting-rings b e, respectively, while the