如图,断开RL,用节点电压法求出 Vc 电位:
(1/11 + 1/3 )* Vc = 16/11 + 1
Vc = 891/154 = 5.786 v
Va = Vc + 3 * (16 - Vc) / 11
= 5.786 + 2.786
= 8.572 V
Vb = 0 V ;电流源内阻无穷大。
Uab = Va - Vb = 8.572 V
Rab = 20 + 8//6 = 23.43Ω
IL = Uab / (23.43 + 4)
= 0.3125 A
求电流源电压:
R = 8 + 24//6 = 12.8 Ω
I = 16/12.8 = 1.25 A
I1 = 1.25 * 6 / 30 = 0.25 A
I2 = 1.25 * 24 / 30 = 1 A
Uab = 0.25 * 20 - 1 * 3 = 2 V
求 画出等效电路,求 Rab 太麻烦了,好像有一个公式可以求,忘了,等高手做吧。
U = Uab - 1 * Rab