1. Circuits Lecture 9: Thevenin and Norton Theorem (2) 李宏毅 Hung-yi Lee

2. Review - Thevenin and Norton Theorem Two Terminal Network Thevenin Theorem Norton Theorem

3. Two Terminal Network Two Terminal Network = Review - Thevenin and Norton Theorem The same concept is applied on i sc.

4. Review - Thevenin and Norton Theorem Two Terminal Network suppress Two Terminal Network suppress Two Terminal Network suppress

5. Review - Thevenin and Norton Theorem Two Terminal Network Two Terminal Network Is it correct? Find v oc Find i sc

6. Outline Maximum Power Transfer Chapter 3.1 Application of Thevenin Theorem

7. Review: Power Consumed Power Suppied Power AB + - reference current should flow from “+” to “-” AB + - reference current should flow from “-” to “+” Negative Communed Power = Supplied Power

8. Ideal Sources i-v curse Larger power Ideal sources can supply unlimited power.

9. Real Source Real voltage sources cannot supply unlimited power Real voltage source = Ideal voltage source + resistor i-v characters for real voltage source

10. Real Source Real current sources cannot supply unlimited power Real current source = Ideal current source || resistor i-v characters for real current source

11. Maximum power transfer Real source Device (Load) power R s is fixed, increase R L Power consumed by R s Power consumed by R L

12. Maximum power transfer Power consumed by R L Maximum power transfer to (consumed by) a load resistance requires R L = R s : (Only 25%)

13. Maximum power transfer When dP L /dR L =0, P L is maximum R L is a variable Find R L which maximizes P L dP L /dR L =0, when R s =R L

14. Power-transfer efficiency Eff=50%

15. Maximum power transfer When R L = R s

16. Maximum power transfer Audio Amplifier Signals from Sound Card http://ming-shian.blogspot.tw/2013/05/radio- tear-down.html Find a speaker that can gain sufficient power

17. Maximum power transfer http://angelfire.com/ab3/mjramp/index.html Audio Amplifier Input audio signal Difficult to compute the power Thevenin Theorem

18. Maximum power transfer (speaker) Sound Card + Audio Amplifier Power consumed by R L

19. Application of Thevenin Which value of R can absorb maximum power? Find the power. +-+- +-+- +-+- p R is maximum when dp R /dR=0

20. Application of Thevenin Which value of R can absorb maximum power? Find the power. +-+- +-+- +-+- Have to find v oc

21. Application of Thevenin Find v oc +-+- +-+- +-+- v oc + -

22. Application of Thevenin +-+- +-+- +-+- +-+- +-+- + - Use Thevenin Theorem several times

23. Application of Thevenin Use Thevenin Theorem several times +-+- +-+- + - +-+-

24. Application of Thevenin Use Thevenin Theorem several times +-+- +-+- +-+- +-+- + -

25. Application of Thevenin Use Thevenin Theorem several times +-+-

26. Remind – Exercise 3.3 What value of R L should be used to obtain the maximum available power?

27. Homework 1ST ORDER DIFFERENTIABLE EQUATIONS https://www.youtube.com/watch?v=2s9z1zLOAJY 2ND ORDER DIFFERENTIABLE EQUATIONS https://www.khanacademy.org/math/differential- equations/second-order-differential-equations/linear- homogeneous-2nd-order/v/2nd-order-linear- homogeneous-differential-equations-1

28. Thank you!

29. Appendix – Non-linear Elements

30. Non-linear Elements (http://www-inst.eecs.berkeley.edu/~ee42/sp03/LectNotes/42_05_6.pdf)

31. Non-linear Elements

32. Which operating regions?

33. Non-linear Elements