i(z.0 iz+△x.) ●●● ●●●● ●●●●● RAZ ●●●0 v(z.) CAz ●●●● v(?+△z,功 ●●●● According to Kicrchoff's voltage and current law 基尔霍夫电压和电流定律 v(z,t)-RAzi(z,1)-LAz oi(=,1) 81 -v(z+Az,)=0 i(z,t)-G△zv(z+△z,t)-C△z v(2+A,0-i(z+△z,t)=0 8t Dividing by△z,and△z→0：ov(z,t)=v(z+△z,t)-(z,t) a(2,0=-Ri(z,t)-L di(z,t) 0z 8t l2.l-Ge,）-co2.0 0z Ot Differential equation for the voltage and current 电压和电流的微分方程 7Differential equation for the voltage and current 电压和电流的微分方程 Dividing by z, and : vzt vz zt vzt (,) ( ,) (,)    According to Kicrchoff’s voltage and current law 基尔霍夫电压和电流定律 7 (,) (,) (,) ( ,) 0 ( ,) (,) ( ,) ( ,) 0 izt v z t R zi z t L z v z z t t vz zt i z t G zv z z t C z i z z t t                          z  0 (,) (,) (,) (,) (,) (,) C vzt izt Ri z t L z t izt vzt Gv z t z t                