()=3() s(o E() (4)①求输入信号的象函数:1,()=1()=oe-()2=30 Is(s ②画S域模型电路:∵零状态, sC 1 1 R R ③求象函数:12(s)=1()13 ,(s)R +1=S+1 +R2R1+一+R2R1+一+R2 120s k1,k2 (6s+3s+1)(2s+1s+1) ④求拉氏逆变换得:()=[2()-(-202+40-1(0 5)①求输入信号的象函数:1,()=L=5 Lio ②画S域模型电路: ③求象函数:()+0()-L 0.5s 57 5+2s3 s+6) +6 北京邮电大学网络学院罗老师编( ) ( ) ( ) ( ) t t t t g t t e t e t e e 3 3 3 2 3 3 7 3 2 3 2 3 3 − − − − = ε − − ε + = ε − + （4）①求输入信号的象函数： ( ) [ ] ( ) [ ( )] 1 1 30 30 + = = = × − s I s L i t L e t t s s ε ②画 S 域模型电路： s s sC 3 1 × 1 1 3 Q零状态,∴ = = ③求象函数： ( ) ( ) ( ) s s R sC R s R R sC R I s R R sC R sC R R sC R I s I s s s 3 6 1 120 1 1 30 1 1 1 1 1 2 1 1 2 1 2 1 2 1 2 2 + + = + + + × = + + = + + + ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ + = ( )( ) ( )( ) 1 40 2 1 20 1 40 2 1 40 2 1 1 2 1 1 40 6 3 1 120 1 2 + + + − = + + + − = + + + = + + = + + = s s s s s k s k s s s s s s ④求拉氏逆变换得：i ( )t L [ ] I (s) e e (t) t t ε ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ = = − + − − − 20 40 2 1 2 1 2 （5）①求输入信号的象函数： ( ) [ ] ( ) 2 1 5 s I s L i t s = = × ②画 S 域模型电路： ③求象函数： ( ) ( ) 2 0 5 3 0.5s s U s U s Li = − + − ( ) ( ) ( ) 6 2 7 2 5 6 15 6 6 5 2 3 2 5 2 5 2 5 2 3 1 2 2 2 0 2 + = + + + = + × + = + ⎟ = + = + = ⎠ ⎞ ⎜ ⎝ ⎛ + − s s s s s s s s s U s s s s s s Li s s U s 北京邮电大学 网络学院 罗老师编 4