1 Analysis and Simulation Exercises ~DC Circuit Analysis (1) Basic Circuit Laws (Kirchhoff ’ s Voltage/ Current Law) Thévenin’s Theorem Norton ’ s Theorem

2 Circuit with three meshes 1

3 Spice file Bridge Circuit for use with Basic Circuit Laws V v R R R R R R OP.PRINT DC I(R1) I(R2) I(R3).PRINT DC I(R4) I(R5) I(R6).DC V 25V 25V 25V.OPT nopage.END

4 Output file (1) **** 09/19/02 11:39:09 ************** PSpice Lite (Mar 2000) ***************** Bridge Circuit for use with Basic Circuit Laws **** CIRCUIT DESCRIPTION******************************************** V v R R R R R R OP.PRINT DC I(R1) I(R2) I(R3).PRINT DC I(R4) I(R5) I(R6).DC V 25V 25V 25V.OPT nopage.END

5 Output file (2) **** DC TRANSFER CURVES TEMPERATURE = DEG C V I(R1) I(R2) I(R3) 2.500E E E E-01 **** DC TRANSFER CURVES TEMPERATURE = DEG C V I(R4) I(R5) I(R6) 2.500E E E E-03 * SMALL SIGNAL BIAS SOLUTION TEMPERATURE = DEG C NODE VOLTAGE NODE VOLTAGE ( 1) ( 2) ( 3) ( 4)

6 Output file (3) VOLTAGE SOURCE CURRENTS NAME CURRENT V E-01 TOTAL POWER DISSIPATION 4.32E+00 WATTS **** OPERATING POINT INFORMATION TEMPERATURE = DEG C JOB CONCLUDED TOTAL JOB TIME.07

7 Verify Kirchhoff ’ s Voltage Law Check V 12 +V 23 +V 30 +V 01 =0 ?? V 1 = V 2 = V 3 = V 4 = V 12 =V 1 -V 2 = , V 23 =V 2 -V 3 =-8.632, V 30 =V 3 =25.000, V 01 =-V 1 = V 12 +V 23 +V 30 +V 01 = =0

8 Verify Kirchhoff ’ s Current Law Finding the sum of the currents entering node 1. For node 1, I 21 +I 01 +I 41 =0. I 21 = -I(R 1 )= 97.04mA, I 01 = -I(R 2 )=-88.85mA, I 41 = -I(R 6 )=-8.184mA I 21 +I 01 +I 41 = = 0.0

9 THÉVENIN’S Theorem Circuit to illustrate Thévenin’s theorem

10 Thévenin voltage and series

11 Spice file Thevenin Circuit for spice V v R R R RL 3 0 1E12.OP.OPT nopage.TF V(3) V.END

12 Simulation Output File (Partial) NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE ( 1) ( 2) ( 3) **** SMALL-SIGNAL CHARACTERISTICS V(3)/V = 6.667E-01 INPUT RESISTANCE AT V = 3.000E+02 OUTPUT RESISTANCE AT V(3) = 2.167E+02

13 Norton ’ s Theorem T Circuit for Norton analysis

14 Spice File Find the short-current for R 4 Norton's Theorem; Find Isc V V R K R K R K R DC V 48V 48V 48V.OP.OPT nopage.PRINT DC I(R4) V(1,2).END

15 Simulation Output File **** DC TRANSFER CURVES TEMPERATURE = DEG C V I(R4) V(1,2) 4.800E E E+01 **** SMALL SIGNAL BIAS SOLUTION TEMPERATURE = DEG C NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE ( 1) ( 2) ( 3) 1.600E-06

16 Question & Answer