Find the Thevenin circuit of terminal a, b6239018V63Solution:V18x6V=18x0c3+63+6R。=3//6+3//6=4Q
6 3 18V a b 3 6 oc 6 3 18 -18 6V 3+6 3+6 V = = 0 R = + = 3// 6 3// 6 4 Find the Thevenin circuit of terminal a, b. Solution:
Apply equivalent transformation to simplify circuit2V.22oa40obSolution:292oa49ob
Apply equivalent transformation to simplify circuit. 1A 2 2 2V 3A 4 a b 3A 1 1A 2 2 2V 3A 4 a b Solution：
2222oaCommon Mistakes : wrong sign for492voltage sourceob4V42+oa2.Forget the voltage493Asourceoboa22ob
2 2V 3A 4 a b 2 2V 4 4V 3A 4 a b 4A 2 a b Common Mistakes： 1. wrong sign for voltage source 2. Forget the voltage source
Find absorbing power of every elements+ 6V_12A19A23Solution:5A+ 4V_P =-72W54I4 = -2AI2 =14ACommon mistakes:P4 =-8WP, = 56W1.Wrong +/- sign2.Wrong unitI, = 3AV, = 2VP, =18WP =6W
Find absorbing power of every elements. 1 2 3 4 5 6V 4V 12A 9A 5A 1 P = −72W 2 I =14A 2 P = 56W 3 V = 2V 3 P =18W 4 I = -2A 4 P = -8W 5 I = 3A 5 P = 6W Solution： Common mistakes： 1. Wrong +/- sign 2. Wrong unit
The supplyingpowerof 8V voltage source is 48WFor element X, find the I, V and absorbing power P52CCO2A421VXab解：流过8V电压源的电流48/8=6A，向上，流过4Q电阻的电流8/4=2A，向下，b节点KCL可得：I6-2=4Ac节点KCL，流过5Q电阻的电流6-2+2=6A，向右，5Q电阻上电压5×6=30V，左正右负d节点KCL，流过3Q电阻的电流6+3-2=7A，向下，3Q电阻上电压7×3=21V，上正下负选择回路X-->8V电压源-->5欧电阻--->Q电阻-->X，KVL：30+21-V-8=0所以V=43V元件X的吸收功率：P=-VI=-43×4=-172W，放出172W功率
The supplying power of 8V voltage source is 48W. For element X, find the I, V and absorbing power P. 解：流过8V电压源的电流48/8=6A，向上，流过4Ω电阻的电流8/4=2A，向下，b节点KCL可 得：I=6-2=4A. c节点KCL，流过5Ω电阻的电流6-2+2=6A，向右，5Ω电阻上电压5×6=30V，左正右负 d节点KCL，流过3Ω电阻的电流6+3-2=7A，向下，3Ω电阻上电压7×3=21V，上正下负 选择回路X->8V电压源->5欧电阻->Ω电阻->X，KVL：30+21-V-8=0 所以V=43V 元件X的吸收功率：P=-VI=-43×4=-172W，放出1 72W功率