1. ECEN 301Discussion #1 – Fundamentals1 DateDayClass No. TitleChaptersHW Due date Lab Due date Exam 1 SeptMonLabor DayNO LAB 2 SeptTue NO LAB 3 SeptWed1Fundamentals2.1 4 SeptThu 5 SeptFri NO Recitation 6 SeptSat 7 SeptSun 8 SeptMon2Kirchoff’s Laws2.2 – 2.3NO LAB 9 SeptTueNO LAB Schedule…

2. Small and Simple Alma 37:6 6 Now ye may suppose that this is foolishness in me; but behold I say unto you, that by small and simple things are great things brought to pass; and small means in many instances doth confound the wise. ECEN 301Discussion #1 – Fundamentals2

3. Lecture 1 – Fundamentals of Electrical Circuits ECEN 301Discussion #1 – Fundamentals3

4. Important Concepts uIdeal/Dependent voltage sources uIdeal/Dependent current sources uElectrical Networks ÙBranches ÙNodes ÙLoops ÙMeshes ECEN 301Discussion #1 – Fundamentals4

5. Ideal Voltage Sources uAn electric device that generates a prescribed voltage uProvides a prescribed voltage across its terminals irrespective of the current flowing through it. The amount of current supplied by the source is determined by the circuit connected to it ECEN 301Discussion #1 – Fundamentals5

6. Ideal Voltage Sources uTime-dependent voltage source ÙVoltage as a function of time t ÙLowercase v usually connotes AC source ECEN 301Discussion #1 – Fundamentals6 + _ v s (t) + _ i Circuit

7. Ideal Voltage Sources uTime-dependent voltage source – special case: sinusoidal ÙVoltage as a function of time t IE: v s (t) = Vcos(ωt) ÙLowercase v usually connotes AC source ECEN 301Discussion #1 – Fundamentals7 + _ v s (t) + _ ~ i Circuit

8. Ideal Voltage Sources uDC voltage source ÙVoltage is not a function of time ÙCapital V connotes DC voltage ÙDC voltage source example: a battery ECEN 301Discussion #1 – Fundamentals8 v + _ + _ VsVs i Circuit A generic voltage is denoted by just a lowercase v

9. Ideal Voltage Sources uSource-load representation ECEN 301Discussion #1 – Fundamentals9 + - Battery Light VsVs + _ v + _ i R v + _ i SourceLoad

10. Ideal Current Sources uAn electric device that generates a prescribed current uProvides a prescribed current to any circuit connected to it. The voltage generated by the source is determined by the circuit connected to it. ECEN 301Discussion #1 – Fundamentals10

11. Ideal Current Sources uLowercase i connotes AC current uCapital I connotes DC current ECEN 301Discussion #1 – Fundamentals11 i s,I s vsvs + _ Circuit

12. Dependent (Controlled) Sources uDiamond shaped source indicates dependent source uDependent sources are an important part of amplifiers Source TypeRelationship Voltage controlled voltage source (VCVS) v s = av x Current controlled voltage source (CCVS) v s = ai x Voltage controlled current source (VCCS) i s = av x Current controlled current source (CCCS) i s = ai x ECEN 301Discussion #1 – Fundamentals12 + _ vsvs isis

13. Electrical Network uA collection of elements through which current flows ECEN 301Discussion #1 – Fundamentals13 V s1 + _ V s2 + _ R1R1 R2R2 R3R3 R4R4 R5R5

14. Electrical Network - Branches uAny portion of a circuit with two terminals connected to it. uMay consist of one or more circuit elements ECEN 301Discussion #1 – Fundamentals14 V s1 + _ V s2 + _ R1R1 R2R2 R3R3 R4R4 R5R5 + _ i v Branch voltage Branch current

15. Electrical Network - Branches uAny portion of a circuit with two terminals connected to it. uMay consist of one or more circuit elements ECEN 301Discussion #1 – Fundamentals15 V s1 + _ V s2 + _ R1R1 R2R2 R3R3 R4R4 R5R5 + _ i v Branch voltage Branch current

16. Electrical Network - Nodes uThe junction of two or more branches uTrivial Node: the junction of only two branches ECEN 301Discussion #1 – Fundamentals16 R1R1 V s1 + _ V s2 + _ R2R2 R3R3 R4R4 R5R5 Node

17. Electrical Network - Nodes uThe junction of two or more branches uTrivial Node: the junction of only two branches ECEN 301Discussion #1 – Fundamentals17 R1R1 V s1 + _ V s2 + _ R2R2 R3R3 R4R4 R5R5 Node Node b Node a Node c

18. Electrical Network – Supernodes uObtained by defining a region that encloses more than one node uCan be treated the exact same way as normal nodes ECEN 301Discussion #1 – Fundamentals18 V s1 + _ V s2 + _ R2R2 R3R3 R4R4 R5R5 Supernode R1R1

19. Electrical Network – Loops uAny enclosed connection of branches ECEN 301Discussion #1 – Fundamentals19 V s1 + _ V s2 + _ R2R2 R3R3 R4R4 R5R5 R1R1

20. Electrical Network – Meshes uA loop that does not contain other loops ECEN 301Discussion #1 – Fundamentals20 V s1 + _ V s2 + _ R2R2 R3R3 R4R4 R5R5 R1R1