1

! ^\

i!

II 't

110 ELECTRICAL APPARATUS

and the two motor coils be shunted respectively by the admit-
tances :

Yi = 0i - jbi, (52)

12 = g% — j&a,
it is then:

/= ..... x•--—..........j--i (53)

the current consumed by the motor, and :

the voltages across the two motor circuits.

The phase difference between EI and j&2 thus is given by

F + Y
m (cos $ + j sin <£) = -r-F1

(54)

(55)

and herefrom follows ^, g and v.

As instance consider a motor of effective admittance per cir-
cuit :

Y = g-jb = 1-3;,

with the two circuits connected in series between single-phase
mains of voltage, eo, and one circuit shunted by a non-inductive
resistance of conductance, g^.

What value of gi gives maximum starting torque, and what
is this torque?

It is:

(53): /=

1

^

(54): ^ = _f^j

(55): m (cos <^> + J sin <
hence:

- jb).

"

tan c6 ==

sin 0 =

(58)