PHASE CONVERSION 223 it is, then, choosing the diagrammatic representation, Fig. 69D: /o - -EoFo = h + Erf, = A, (9) Eo = Et + 2 Z (I, + $2y0), (10) h = EtYf, (11) substituting (11) into "(10) and transposing, gives: if the diagram, Fig. 692?, is used, it is : which differs very little from (12). And, substituting (11) and (12) into (9): h = #2 (7o + Fa) + #oY"o, • « P 72+27o+2Zro(y0+72) (14) Equations (11), (12) and (13) give for any value of load, 72, on the quadrature phase, the values of voltage, #2, and current, /2, of this phase, and the supply current, I0, at supply voltage, $0. It must be understood, however, that the actual quadrature voltage is not #2, but is ^2, carried a quarter phase forward by the rotation, as discussed before. 132. As instance, consider a phase converter operating at con- stant supply voltage : $0 = e0 = 100 volts; of the constants : YQ = 0.01 - O.f j, Z0 = Zi = 0.05 + 0.15 j; thus: Z = 0.1 + 0.3 j; and let: Yz = a (p - jq) = a (0.8 - 0.6 j), that is, a load of 80 per cent, power-factor, which corresponds about to the average power-factor of an induction motor,