d u 2+RCuc+h=as(t≥0) →LC=C dt ②以i()为变量 uR()+u(+uc(t)=us(t(t20 di i()=i1,u2(t)=Ri,u1()=Lm, uc(t= C Jo (5)ds di dt coi(s)ds=us →Ri1+L=+ 1 (t≥0) 的2RC d i d →LC 2+i1=C=8(t≥0) dt dt一、动态电路的微分方程 ( 0) 2 2    u  u t  dt du RC dt d u LC C S C C u (t) u (t) u (t)  u (t)(t  0) R L C S ( ) , R R L ( ) , u t  i L i t  i ( ) , dt di u t L L L  i  d C u t t C   L 0 ( ) 1 ( ) ( ) ( 0) 1 0       i d u t dt C di Ri L S t L L L   ( 0) 2 2     t  dt du i C dt di RC dt d i LC S L L L ②以iL(t)为变量