1. Lecture 5 Source Transformation Thevenin Equivalent Circuit Norton Equivalent Circuit

2. Source Transformation Show that i S =v S /R for any R L

3. Application Determine whether the 6V source is absorbing or delivering the power.

4. Step-by-step simplification

5. Redundant Resistor (1) Prove that the left circuit and the right circuit are equivalent for any load resistor.

6. Redundant Resistor (2) Prove that the left circuit and the right circuit are equivalent for any load resistor.

7. Example 4.9

8. Simplified Circuit

9. Thevenin Equivalent Circuit

10. V Th If R L =∞, then V ab =V TH If R L =0, the short circuit current from a to b (i.e. i ab ) should equal to i sc =V Th /R TH. So R TH =V Th /i sc

11. Determine v ab Show that V TH = v ab

12. Determine i SC and R TH

13. Example 4.10 Determine the Thevenin Equivalent Voltage

14. Example 4.10 1.Determine the short circuit current 2.Determine R TH

15. Methods of Finding R TH R TH =V TH /i SC If the network contains only independent soruces: – Deactivate a voltage source by replacing it with a short – Deactivate a current source by replacing it with an open If the network contains dependent sources – Apply a test source

16. If the network contains only independent soruces

17. R TH

19. Norton Equivalent Circuit A Norton Equivalent circuit consists of – Short-Circuit Current – Norton Equivalent Resistance, which is equal to Thevenin Equivalent Resistance

20. Derivation of Norton Equivalent Circuit

21. Extra Credit Assignment Derive 4.1-4.3

22. More about the Extra Credit Assignment