General branch of a linear time-invariant network bk -branch current sk bk Ubk --branch voltage ek element current ek element voltage k sk current source 十 bk sk voLtage source k -element impedance KCL: ibk =iek -isk k=l, 2, . B KVL: Ubk=Uek -Usk k=1, 2, .. B VCR:(DUek=riek k=1, 2,., B (2)Uek iek (tdt or vek(s)=le(s) i k k or yek (S)=sLKlek(S) dtGeneral branch of a linear time-invariant network i branch current bk − − bk − −branch voltage i element current ek − − ek − −element voltage  sk − −voltage source i sk − −current source Zek − −element impedance KCL : i bk = i ek − i s k k = 1,2,  ,B KVL:  bk =  ek − s k k = 1,2,  ,B VCR: (1)ek = Rk i ek k = 1,2,  ,B ( ) 1 ( ) ( ) 1 (2) 0 I s sC i d or V s C ek k ek t t ek k ek = =     (3) or V (s) sL I (s) dt di L ek k ek ek ek = k = bk i ek i sk i +ek − + bk −  sk Zek