A Symbolic Analysis of Relay and Switching Circuits

19
terminals if and only if Xjk =Y jk .j, k
= 1, 2, :3,-. •• n
'r.7r~er·e X is the hinderance on network 1-T bet~veen termijk
nels ,1 and k, and Y is that for 11 between the corjk
respondin~ terminals.
Thus under this definition the equ_ivelenc3s
of the preceding sections were \\'1 th respect to two
Star-Mesh end Delta-vVye Transformations.
. -
As in ordinary
network theory there exiet :3 l;l:1r to me fJh 2nd delta
to vvy-e transforms tions. The delta to wye tl~8n sformstion
is shown in Fig. 8. These two netwo~ks are
equivalent with respect to the three terminal~ a,
b, and c, since by the distrllntive law X ab
= R(S + T)
=RS + RT and similarly for the other pairs of terminels
a-c end b-c.
a
R
b- - b
1R·S
S
T
-
ReT S·T
a/ 'c
Fig. 8