Download Lec #10 ppt

Announcements
1. Midterm No. 1 Thursday Oct. 6 in class; one 8-1/2 x 11 sheet of notes
allowed. No text, no calculator, no operating cell phones; no blue books
needed.
2. The next lab will begin on Monday Oct. 10 (RC filters)
3. Be sure to put your discussion section leader’s name on your homework
to facilitate its return to you.
4. HW 5 is due at 12:00 noon Tuesday Oct. 4 in 42/100 boxes in 240 Cory.
Solutions will be put on top of the boxes at 1 pm that day.
5. Midterm 1 will not include a problem on 2nd-order transients.
6. Prof. Fearing will conduct a review session in class Tuesday Oct. 4.
7. A list of topics covered to date will appear shortly on the web site.
EE 42/100: Running Checklist of Electronics Terms (Midterm 1)
28 Sept. 2005 – Dick White
Terms are listed roughly in order of their introduction. Terms in square braces [like this] are for information only.
TERM
Charge, current, voltage, resistance, capacitance, inductance,
transformer turns ratio, electrical energy, electric power
Coulomb, ampere, volt, ohm, farad, henry, joule, watt
Kirchhoff’s Current Law, Kirchhoff’s Voltage Law, Ohm’s Law,
i-v relations for Rs, Cs, Ls
Series connection, parallel connection
DC (steady excitation)
Independent and dependent ideal voltage and current source
First-order transient circuits (RC, RL); time constant;
[2nd-order transients]
Multimeter (DMM), [Oscilloscope]
Prefixes (milli-, etc.)
Nodal analysis (node, supernode)
Loop analysis (mesh, branch)
Superposition (linear elements)
Maximum power transfer
Voltage divider, current divider
Equivalent circuits (Rs, Cs or Ls in series/parallel; Thevenin,
Norton)
Power delivery, dissipation
Types of Circuit Excitation
Linear TimeInvariant
Circuit
Linear TimeInvariant
Circuit
Steady-State Excitation
(DC Steady-State)
Linear TimeInvariant
Circuit
Sinusoidal (SingleFrequency) Excitation
AC Steady-State
OR
Digital
Pulse
Source
Linear TimeInvariant
Circuit
Transient Excitation
Coming Attraction!
Why is Single-Frequency Excitation
Important?
• Some circuits are driven by a single-frequency
sinusoidal source.
• Some circuits are driven by sinusoidal sources
whose frequency changes slowly over time.
• You can express any periodic electrical signal as
a sum of single-frequency sinusoids – so you
can analyze the response of the (linear, timeinvariant) circuit to each individual frequency
component and then sum the responses to get
the total response.
• This is known as Fourier Transform and is
tremendously important to all kinds of engineering
disciplines!
Representing a Square Wave as a Sum of Sinusoids
Time (ms)
Signal
signal(V)
Relative Amplitude
d
Signal (V)
c
Signal
signal(V)
b
a
Frequenc y (Hz)
(a)Square wave with 1-second period. (b) Fundamental component
(dotted) with 1-second period, third-harmonic (solid black) with1/3-second
period, and their sum (blue). (c) Sum of first ten components. (d)
Spectrum with 20 terms.