1. Lecture 41 EEE 302 Electrical Networks II Dr. Keith E. Holbert Summer 2001

2. Lecture 42 Thevenin/Norton Analysis 1. Pick a good breaking point in the circuit (cannot split a dependent source and its control variable). 2. Thevenin: Compute the open circuit voltage, V OC. Norton: Compute the short circuit current, I SC. For case 3(b) both V OC =0 and I SC =0 [so skip step 2]

3. Lecture 43 Thevenin/Norton Analysis 3. Compute the Thevenin equivalent resistance, R Th (or impedance, Z Th ). (a) If there are only independent sources, then short circuit all the voltage sources and open circuit the current sources (just like superposition). (b) If there are only dependent sources, then must use a test voltage or current source in order to calculate R Th (or Z Th ) = V Test /I test (c) If there are both independent and dependent sources, then compute R Th (or Z Th ) from V OC /I SC.

4. Lecture 44 Thevenin/Norton Analysis 4. Thevenin: Replace circuit with V OC in series with R Th, Z Th. Norton: Replace circuit with I SC in parallel with R Th, Z Th. Note: for 3(b) the equivalent network is merely R Th (or Z Th ), that is, no voltage (or current) source. Only steps 2 & 4 differ from Thevenin & Norton!

5. Lecture 45 Independent Sources (Norton) Circuit with one or more independent sources R Th Norton equivalent circuit I sc

6. Lecture 46 No Independent Sources Circuit without independent sources R Th Thevenin equivalent circuit

7. Lecture 47 Class Example Extension Exercise E8.18

8. Lecture 48 PSpice Analysis of AC Circuits Should have done this in ECE 301 We must use AC sources, and tell PSpice to perform an AC analysis at specific frequency(ies) PROBE allows us to plot our results Take advantage of features (e.g., cursors) to assist your analysis Completely annotate your schematic diagrams MOST IMPORTANT RULE: You will always get an answer, you must judge its validity!

9. Lecture 49 Class Example Extension Exercise E8.19