Abstract :
THREE independent electrical circuits which are coupled together magnetically may be represented by an equivalent circuit developed from fundamental equations. In general, these transformers may be divided into two distinct types depending upon the relative directions of the mutual fluxes between the three windings. According to C. F. Estwick, (M´25) of the General Railway Signal Company, Rochester, N. Y., who discusses this type of transformer in a current A.I.E.E. paper, any arrangement of three coupled circuits will have the characteristics of either one or the other of the two types mentioned.
