Physics 116A, Fall, 2004

Lab: Sec. 1 - W 3:10-6:00 PM in Rm. 152 Roessler
Sec. 2 - M 3:10-6:00 PM in Rm. 152 Roessler

Instructor: Prof. David E. Pellett, 337 Physics, (530) 752-1783,

Office hour: After Dec. 1 – Fridays 10:30-11:30 AM in 152 Roessler, or by appointment.

E-mail: pellett@physics.ucdavis.edu.

TA: Juan Lizarazo, 331 Physics,

Office hour: TBA

E-mail: jflizarazo@ucdavis.edu

Physics 116A is an introduction to analog electronics. It is valuable for students who want to do experimental work, who want to understand the basis of our omnipresent electronic technology or who want to develop new instrumentation or technology. The course is a prerequisite for Physics 116B, which covers digital electronics and computer fundamentals.

Text: Bobrow, Fundamentals of Electrical Engineering, 2nd ed.

Lab manual: see links in the chart below.

Scope: Material on analog electronics in Ch. 1-10 and Ch. 16 of text by Bobrow.

Lecture "Slides:" For some lectures last year, "slides" were prepared and projected from a laptop computer. These typically covered assignments, lecture outlines and class notes if appropriate. If I use such notes again in class this year, I will post them afterwards as .pdf files in the chart below in one of the columns labeled "| M | W | F |" with a link shown as "L.S." for "lecture slides."

Download Class Fact Sheet and Schedule (.pdf format) here.

The .pdf files require Adobe Acrobat 3.0 reader (or later).

• PDF reader download site (Adobe Systems).

Assignment 1: Read Bobrow, Ch. 1, Ch. 2; Problems due 10/11/04: Ch. 1: 1.8(a,c), 1.17(a)[note v_s=v in figure], 1.18(a), 1.21, 1.23(c), 1.34 (assume R = 0.5 ohms), 1.42(b), 1.53, 1.57; Ch. 2: 2.2.

• Assignment 1 solutions available here.

Assignment 2:

Read Ch.3. This introduces the capacitor and inductor as linear circuit elements (very important) and the Op Amp differentiator and integrator discussed in class and Lab 2. There is also a review of ODE's (ordinary differential equations) with constant coefficients and damped oscillations in LRC circuits. I say "review" since ODE's are covered in the Math 22 series. Read it over to see the connection between ODE's and circuits. Physics 116A will be concerned mainly with steady state AC circuit response (i.e., for sinusoidal inputs).We will return to the step function response of circuits in more detail in Physics 116B.

Read 4.1-4.5 to understand the use of complex V, I and impedance, Z, to find the steady state AC respose of a circuit. Also includes AC power and rms values of V and I.

Read 5.1 on frequency response of an RC circuit (needed for lab 3).

• Problems due 10/18/04 (still on DC circuits): Ch. 2: 2.8, 2.14, 2.20, 2.24, 2.28, 2.30, 2.37, 2.39.
• Assignment 2 solutions available here.

Assignment 3:

• Read 5.2-5.4:
  • resonance
  • complex frequency, s
  • linear systems with feedback
    (We'll return to feedback near the end of 116A)
• We may also touch on 5.5-5.7:
  • quick introduction to s as Laplace transform variable
  • overview of circuit analysis using Laplace transforms
  • Detailed applications of Laplace transforms are left for 116B
• Problems due 10/25/04: Ch. 3: 3.5, 3.7; Ch. 4: 4.7, 4.9, 4.12, 4.16, 4.18, 4.29.
• Assignment 3 solutions available here.

Assignment 4:

• Read 16.1-16.3 on SPICE (for lab next week)
• Problems due 11/1/04: Ch. 5: Work the 4 problems in last year's Exam 1 plus Ch. 5: 5.5, 5.21(refer to the high-Q coil discussion in Sec. 5.2), 5.39, 5.41(a,c).
  • For the following discussion, see if your browser can reproduce Greek characters. This should look like the lower case Greek character, omega: ω. And this should look like a lower case sigma: σ. If another character/font appears, you may have to try to recognize it for what it is supposed to represent.
  • A Note on complex frequency, s:
    • Prob. 4(d) on Exam 1 and Prob. 5.41 use the concept of complex frequency, s=σ+jω. This is explained in Sec. 5.3 and example 5.6 of the text. The response of a linear circuit driven by V_in=V_sexp(st) can be found just as was done before for complex sinusoids (V_in=V_sexp(jωt)). Resulting expressions will then have s substituted for jω wherever jω appeared in the sinusoid case. The impedance of an inductor would be Z=sL instead of jωL. For a capacitor, Z=1/(sC). You can do circuit analysis for complex s as was done before with jω but using these impedance relations in terms of s rather than jω.
    • Note that the usual sinusoidal expressions are obtained if we let σ=0 (s=jω, on the imaginary axis in the complex frequency plane). For nonzero σ, we have functions which are sinusoids multiplied by exp(σt). Such sinusoids decay exponentially for σ<0 (s in left half of complex frequency plane) or grow exponentially for σ>0 (s in right half of complex frequency plane).
    • For Prob. 4(d) on Exam 1, see the discussion starting on p. 293 of the text. This explains poles and zeros of the transfer function H(s).
• Assignment 4 solutions: Last year's Exam 1 solution and problem solutions from text.
  • Note on Prob. 5.21: the High-Q coil criterion is not met in this case. Find the resonance frequency (or frequencies) using the text resonance criterion, namely the frequency ω such that the imaginary part of the admittance (or impedance) equals zero (for a circuit with at least one capacitor and one inductor). Details on text, p. 276.
• An exam is coming next Wednesday over material covered in Ch. 1-5 (through end of Sec. 5.3). You may bring one 8.5 in x 11 in sheet of paper with information of your choice to refer to during the exam. Otherwise, it is closed book and notes. Bring a calculator and blank paper to write on. You will need to show reasoning for full credit. A copy of a past exam is here and the solutions here (.pdf).

Assignment 5:

• Here are notes on active filters from Friday's lecture. It shows the connection between the complex frequency plane and the Laplace transform. The material on filter design in pp. 2-4 does not depend on the use of Laplace transforms. Also see the "lecture slides" from Friday, Nov. 5.
• Read Ch. 6 on semiconductors and diodes, excluding pp. 377-81 (on diode logic circuits, left for 116B)
  • Semiconductor fundamentals and diodes will be introduced in class starting Monday, Nov. 6.
  • Also read and try to understand the material for Lab 6 on diode characteristics as much as possible before the lab. The diode characteristic IV curve is covered in Sec. 6.3. Diode rectifiers are discussed in the beginning of Sec. 6.4. Zener diodes are covered in Sec. 6.6.
• Problems due Wednesday, 11/8/04: Ch. 5: 5.49 (Note: find H(s), then make the pole-zero plots for the values of C. This circuit might be familiar from the notes linked above in this assignment.);Ch. 6: 6.2, 6.5.
• Assignment 5 solutions are here.

Assignment 6:

• Read 7.1-7.3, 9.1 (BJT basics and amplifiers) - needed for the lab, week of Nov. 15;
• Problems due Monday, 11/15/04: 6.8, 6.16, 6.21(a), 6.45, 6.74.
• Assignment 6 solutions are here.

Assignment 7:

• Read 8.1, 8.2, 9.2 (FET basics and amplifiers) - needed for the lab, week of Nov. 22;
• For BJT transistor amplifiers (common collector or emitter follower, common emitter, common base - covered in Chapter 9),
  • learn how to determine the operating point ("Q point) of a transistor amplifier (BJT biasing);
  • learn about the simple Ebers-Moll and small signal BJT models;
  • learn how to derive the circuit for the small signal AC model of an amplifier from the actual amplifier circuit;
  • learn how to use the small signal model to derive the amplifier voltage gain, input impedance, output impedance, etc.
• Problems due Monday, 11/22/04: Diode problem (available here) plus 7.3, 7.11, 9.3, 9.12, 9.14, 9.19.
• An exam is coming next Wednesday. It will emphasize material since the first midterm, covering semiconductors (including notes) and the assigned material on diodes and BJTs in Ch. 6, 7 and Sec. 9.1 of the text.
  • You may bring two 8.5" by 11" sheets of paper with information of your choice.
  • A copy of a previous exam (with solutions) is here. (Note: this one covered JFETs, unlike this year's exam 2.)
• Assignment 7 solutions: Diode problem solution here; Bobrow problem solutions here.

Assignment 8 (for week 9):

• Read 9.3, 9.4, 10.1.
• Before coming to lab, read the lab writeup and notes for Week 9 (BJT Differential Amplifier) and do the prelab calculation.
• Problems due Monday, 12/6/04 (note change–see information below on Prob. 9.21): 8.6, 8.8, 8.12, 8.40, 9.21*, 9.30, 9.39, 9.41.
• Assignment 8 solutions here.

*Note: there are some difficulties in the way Prob. 9.21 is stated in the text. Refer to the modified figure:

• You will need to make a small-signal AC diagram for this circuit to do the analysis. I suggest that you use the small-signal AC BJT model shown in the figure above. (See the solution to Prob. 3 on Exam 2 for an example of its use.)
• All three C's are assumed to be infinitely large.
• v_s and the 1 kOhm resistor are not needed for this problem so I left them off.
• The voltage gain is not stated correctly. It should be A_v = v_out/v_in = v_c/v_e.
• The input resistance (or impedance) is R_in = v_in/i_in.
• The output resistance is the resistance looking from the output node back into C₂ (i.e., to the left, back toward the collector and the 10 kOhm resistor).

Assignment 9 (for week 10):

• Read Ch. 10: 10.2-10.4. You aren't responsible for the details of the inner workings of the LM741 in Sec. 10.2 but there are some useful concepts presented, so it is worth reading. Optional: read 10.6 about RF communication.
• Problems due Friday, 12/10/04: 9.55, 9.56, 9.71; 10.35, 10.45, 10.48, 10.49, 10.54(a), 10.58.
• Note: This is a long assignment and some problems are more important to the course than others, so I will list them in order of priority (highest priority first). You will get credit for whichever ones you work and turn in.
  • The following six are "important" and should be turned in:
    • 9.55, 9.56 (like examples in class notes (L.S.) from 12/8, in the class outline, above)
    • 10.35 (effect of feedback on voltage amplifier parameters)
    • 10.45 (use of the constant gain-bandwidth product for an op-amp like the 741)
    • 10.54(a) (phase shift oscillator using a JFET instead of an op-amp)
    • 10.58 (another oscillator configuration using an op-amp).
  • The following are less important but you should be able to handle them: 10.48, 10.49.
  • The following has not been discussed at all so far: 9.71. I will say a few words about this topic Friday. Here is the solution to a similar problem (9.69).
• A sample final exam has been posted below (Announcements, 12/8/04).
• Assignment 9 solutions here.

Here is a copy of Exam 2 with solutions.
There is a misprint and missing information in Prob. 9.21 of Assignment 8, as explained above. The problem is sufficiently important that I have decided to change the "due date." The Assignment 8 problem set will be due Monday, 12/6 instead of today.

About Prob. 5: this topic was not emphasized in 2004, so it won't be emphasized on this year’s final. Nonetheless, you should be aware of load lines and power considerations from reading the material in Ch. 9.

• Harold Black and the Negative-Feedback Amplifier
• Notes on complex frequency , s, poles of the transfer function, H(s), and Laplace transforms with figures.
• Early "spark gap" transmitters: (a) Spark Transmitters; (b) History of early spark transmitters and simulation of the waveforms of their transmissions.
• A Java simulation of the Kronig-Penney model of wavefunctions in a one-dimensional periodic potential.
• News: First observation of the spin Hall effect by Awschalom, et al. at UCSB (Published in Science, 11 Nov. 2004). Use of the electron spin in electronic devices ("spintronics") is thought to be an important direction for advances in technology. For example, the spin-dependent giant magnetoresistance (GMR) is used for computer disk read heads.
• D. Pellett research interests
• The Pixel detector for the CMS facility at the CERN LHC.
• The "silicon retina" and other projects to make "seeing silicon".
• The physics of computation group home page at Caltech.
• The connection of neuron cells to an electronic interface.
• Information on SPICE and personal computer versions:
  • SPICE documentation in .pdf form: copyright notice, table of contents, document body
  • General SPICE distribution from Berkeley (various systems: UNIX, MS-DOS, ...)
  • SPICE Linux rpm for i386 (This is 3f4. Rpmfind or Google can also help you find Spice 3f5 for Linux)
  • PSPICE 9.1 Student Version (Windows) file still seems to be available here.
  • WinSPICE: Spice3 for Windows (including XP) from S.C. Wong of the Hong Kong Polytechnic University..
  • MacSpice 3f5 from Charles D.H. Williams, University of Exeter School of Physics. Now for Mac OS X!
• Transistorized!, a PBS program about transistors (explore the various links - includes demo of prototype point contact transistor).
• Some physicists who made inventions or advances in electronics (note that these advanced physics in most cases):
  • John Bardeen with Nobel prizes for the transistor and superconductivity theory;
  • Robert Noyce, co-(but separate) inventor of the integrated circuit (he was awarded the patent but Ted Hoff of Texas Instruments was awarded the Nobel Prize in 2000, too late for Noyce, who died in 1990, to be considered); co-founder of Intel;
  • Bruno Rossi, cosmic ray pioneer and inventor of the Rossi coincidence circuit (first electronic "and");
  • Luis Alvarez, member of inventor hall of fame and Nobel physics laureate (elementary paticle physics).