1. Lecture 6: Thevenin and Norton Equivalents, Maximum Power Transfer, & Superposition Nilsson & Riedel 4.10-4.13 ENG17 (Sec. 2): Circuits I Spring 2014 1 April 17, 2014

2. Overview Thevenin Equivalent Norton Equivalent Special Cases Maximum Power Transfer Superposition 2

3. Thevenin Equivalent Circuit 3 Independent voltage source in series with resistor Provides simplified equivalence to more complex circuit

4. Finding Thevenin Equivalent 4

5. Overview Thevenin Equivalent Norton Equivalent Special Cases Maximum Power Transfer Superposition 5

6. Norton Equivalent Circuit 6 Independent current source in parallel with resistor Provides simplified equivalence to more complex circuit Relates to Thevenin Equivalent (source transformation)

7. Finding Norton Equivalent 7

8. Overview Thevenin Equivalent Norton Equivalent Special Cases Maximum Power Transfer Superposition 8

9. With Dependent Source 9

10. Alternate Method 10

11. Overview Thevenin Equivalent Norton Equivalent Special Cases Maximum Power Transfer Superposition 11

12. Power Transfer Two issues: –Efficiency of Power Transfer –Amount of Power Transfer 12

13. Maximum Power Transfer 13

14. Example 14 Find value of R L that results in maximum power transfer. Use Thevenin Equivalent circuit.

15. Overview Thevenin Equivalent Norton Equivalent Special Cases Maximum Power Transfer Superposition 15

16. Superposition Applies to linear system Defined: when linear system is excited by >1 independent energy sources, the total response is the sum of individual responses. Clarified –Deactivate 1 st source, find response from 2 nd source –Deactivate 2 nd source, find response from 1 st source –Add these responses 16

17. In practice May not help so much right now… 17

18. w/Dependent Sources 18

19. Overview Thevenin Equivalent Norton Equivalent Special Cases Maximum Power Transfer Superposition 19