104 ELECTRICAL APPARATUS

El = JiZ and E» = /2Z

Z Z

and the phase angle between EI and $2 is given by:

r? [ 2^

m (cos 0 + j sin <£) = ^-T~^-

(34)

(35)

Denoting the absolute values of the voltages and currents by
small letters, it is:

T = &ei62 sin 0; (36)

in the motor as quarter-phase motor, with voltage, e0, impressed
per circuit, it is:

To = 6eo2, (37)

hence, the torque ratio:

t = -122 sin 0. (38)

The current per circuit, in the machine as quarter-phase motor,
is:

io = ~> (39)

z ^ J

hence the volt-amperes:

Qo = 2e0^o, (40)

while the volt-amperes of the single-phase motor, inclusive start-
ing impedances, are:

Q = e0i, (41)

thus:

i iz

and, the apparent torque eflB.ciency of the starting device:

(43)

^ J

68. As an instance, consider the motor of effective impedance:
Z = r +jx = 0.1 + 0.3 j,

z = 0.316,

thus: