5-6一阶电路的三要素法 R RC duct L (t)=ls(t≥0) dt Cu GLm+()=i、(≥0) G13i(0)=l05-6 一阶电路的三要素法 iS G L iL C + uS - R + uC -      = + =  + C 0 C S C (0 ) ( ) ( 0) d d ( ) u U u t u t t u t RC      = + =  + L 0 L S L (0 ) ( ) ( 0) d d ( ) i I i t i t t i t G L