ESE 271: Electrical Circuit Analysis
Spring 2013
Web site:
www.ece.sunysb.edu/~oe/leon.html
visit website regularly for updates and announcements
Text Books:
R.E. Thomas, A.J. Rosa, G.J. Toussaint,
The analysis and design of linear circuits
circuits”,
“The
7th edition, Willey, ISBN 978-1-118-06558-7
Instructor:
Leon Shterengas (631-632-9376, leon@ece.sunysb.edu);
Offi hhours: TU
Office
TU,TH
TH 10
10-12am,
12
Li
Light
ht E
Engineering
i
i Bld
Bldg. 143
Teacher assistants:
p
see website for updates
Grading:
Homeworks - 40%, Exams - 60%
Any questions regarding the grading must be resolved
within one week after grade was given.
given
ESE 271: Electrical Circuit Analysis
Spring 2013
Course Description:
Resistors, capacitors, inductors. Kirchhoff’s and Ohm’s law. Nodal and mesh analysis. Equivalent
circuits Steady-state
circuits.
Steady state AC circuits.
circuits Phasors.
Phasors Transient analysis.
analysis Fourier and Laplace transforms.
transforms
Fundamentals of AC power, coupled inductors (transformers), and two-port networks.
The course is designed to provide the necessary theoretical background for electronic lecture and lab
courses like ESE 211,
211 218,
218 311,
311 314,
314 324,
324 372,
372 etc.
etc
Class notes, homework assignments and problem solutions can be downloaded from
www.ece.sunysb.edu/~oe/leon.html.
Homeworks are due in the beginning of the corresponding lecture.
Lectures:
M/W
2 30pm - 3.50pm
2.30pm
3 50pm
Recitations:
R01
R02
R03
M(21)
W(16)
F(5)
P118
11.00am - 11.53am
11.00am - 11.53pm
11 00am - 11.53am
11.00am
11 53am
Melville Library N4000
Chemistry 126
Chemistry 123
ESE 271: Electrical Circuit Analysis
Spring 2013: Tentative Schedule
W k 01
Week
Week 02
Week 03
Week 04
Week 05
Week 06
Week 07
Week 08
W k 09
Week
Week 10
Week 11
Week 12
Week 13
Week 14
Week 15
Finals
JJan. 28
Jan. 30
Feb. 4
Feb. 6
Feb. 11
Feb 13
Feb.
Feb. 18
Feb. 20
Feb. 25
Feb. 27
Mar. 4
Mar. 6
Mar. 11
Mar. 13
Mar. 18
Mar. 20
M 25
Mar.
Mar. 27
Apr. 1
Apr. 3
Apr. 8
Apr. 10
Apr. 15
Apr. 17
Apr. 22
Apr. 24
Apr. 29
May. 1
May. 6
May. 8
May. 11-22
L01. Current.
L01
C
t Voltage.
V lt
Energy.
E
Power.
P
Passive
P i sign
i convention.
ti
L02. Kirchhoff’s laws. Resistor. Ohm’s law.
L03. Series and parallel connections. Thevenin and Norton equivalents.
L04. Dependent sources and Operational Amplifiers.
L05. Circuits with Op. Amps.
L06 Nodal analysis.
L06.
analysis
L07. Mesh analysis.
L08. Material review.
Midterm exam 1.
L09. Capacitors.
L10. Inductors.
L11. RC and RL circuits. Time constants. Step response.
L12. RLC circuit under harmonic excitation.
L13. Complex impedance. Ohm’s law for phasors.
Spring break
Spring break
L14 Phasor
L14.
Ph
di
diagrams.
L15. AC steady state analysis: Norton and Thevenin equivalents. Nodal analysis.
L16. AC steady state analysis: Mesh analysis. Superposition.
L17. Complex power. RMS. Maximum power delivery.
L18. Frequency response of the first order circuits. Bode plots.
Midterm exam 2.
L19. Laplace transform.
L20. Laplace transform.
L21. Circuits in s-domain. Transfer function.
L22. Step and impulse responses. Poles. Stable circuits.
L23. Frequency response function. Bode plots.
L24. Resonance. Filters.
L25. Mutual inductance. Transformer.
L26. Material review.
Final exam
HW1 due
HW2 due
HW3 due
HW4 ddue
HW5 due
HW6 due
HW7 due
ESE 271 / Spring 2013 / Lecture 1
Electric charge
Coulomb’s law
Case 1: sign(Q) = sign(q)
Case 1: sign(Q) = ‐
g (Q)
sign(q)
g (q)
Example
1
ESE 271 / Spring 2013 / Lecture 1
Electric field
Electric field created by Q at distance R
In general:
Force acting on charge q in electric field:
2
ESE 271 / Spring 2013 / Lecture 1
Voltage
Experiment Gedanken
(thought experiment)
1. At
At t t = 0 put q 0 put q > 0 with zero velocity at x 0 with zero velocity at x = 0.
0.
Since velocity is zero the charge has
zero kinetic energy at t = 0.
2.
Let this charge go
Th h
The charge will accelerate in electric field and
ill
l t i l t i fi ld d
after some time its velocity becomes > 0.
This means that charge got kinetic energy. This energy charge got from the electric
field thanks to work performed by force:
Voltage difference between x = 0 and x = ∆x
3
ESE 271 / Spring 2013 / Lecture 1
Voltage drop/rise across circuit element
To be able to calculate the voltage drop across circuit element, the
voltages present at its terminals should be measured with respect to
the common reference point, for instance, circuit ground.
4
ESE 271 / Spring 2013 / Lecture 1
Electric current
Definition:
Example
Current
Current density
inside cylindrical volume
there are
charges
all of them are moving with velocity
Volume concentration of mobile charges
5
ESE 271 / Spring 2013 / Lecture 1
Current flowing through circuit element
C
Conventional
ti
l currentt – equivalent
i l t flflow off positive
iti charges.
h
Arrow shows the direction of conventional current if
Arrow shows the direction of conventional current if
We will deal with electrically neutral circuit elements.
6
ESE 271 / Spring 2013 / Lecture 1
Energy and Power
Was created by external source of energy, ex. battery.
Flows only if the circuit element has mobile charges.
Energy given to circuit element during ∆t:
Power:
Positive power means absorption of energy by circuit element, p
p
gy y
,
sometimes they say that it means circuit element works as a load.
7
ESE 271 / Spring 2013 / Lecture 1
Passive sign convention and passive circuit elements
If current and voltage were assigned to circuit element following passive sign convention above:
Circuit element absorbs energy/power ‐ load.
Circuit element generates energy/power ‐ generator.
Energy delivered to circuit element during period of time from t0 to t:
Passive circuit elements can not deliver more energy Passive
circuit elements can not deliver more energy
than they absorbed previously, hence for them always:
8
ESE 271 / Spring 2013 / Lecture 1
Active circuit elements
Example
Polarities of the voltages and directions of currents satisfy passive sign convention,
fy p
g
,
hence:
This battery generates energy/power and PS < 0.
This is an example of active circuit element.
More generally: active circuit elements can generate more energy/power than they absorbed previously, hence for active elements one can have:
previously, hence for active elements one can have:
9
ESE 271 / Spring 2013 / Lecture 1
Ideal independent current and voltage sources
For DC:
Voltage:
Keeps voltage fixed for any current, i.e. can generate any power.
Current:
For DC:
Keeps current fixed for any voltage i.e. can generate any
voltage, i.e. can generate any power.
Ideal sources are clearly active elements but can act as loads and as generators depending on other elements present in the circuit.
10
ESE 271 / Spring 2013 / Lecture 1
Examples
11
ESE 271 / Spring 2013 / Lecture 1
Electric circuit
Here everything is clear and simple.
What if we have mode complicated case?
Example
Model connection wire as an ideal conductor, i.e. no charge accumulation, no voltage drop, accu
u at o , o o tage d op,
no power dissipation.
We will be working with lumped‐parameter model circuits (energy is lumped within circuit elements)
12