Transcript 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.