tt =31 = 3R18C9.

. 166 t1 = 12 .

t2 = 2 = R209,

. . t2 = 1,5 . , . , . R19 2.

, R21 R22. .

. 164, . 165. 1 2 5 , .

1 2. 3, , 4 R12