Synopsis


The course provide laboratory practice and experimental studies on topics covered in ECS 301 or ECS 303. The course will give laboratory practice and experimental studies on topics mainly covered in ECS 301 Basic Circuit Analysis or ECS 303 Basic Electrical Engineering.  Topics include basic circuit theory, dc and ac measurements, RLC circuits, nonlinear components, and operational amplifiers.

Lab and Equipment

Announcements

  • Tips for the exam
    • rms means root-mean-square.
      • You first square the signal, then find the average of that squared version of the signal. The rms value is the square root of the average you got earlier.
      • For zero-mean sinusoidal waveform, the rms value is equal to the value of its amplitude (0 to peak) divided by sqrt(2).
        • For a more general sinusoidal waveform: Asin(x) + D, where D is the DC offset, the rms value is sqrt((A^2)/2 + D^2).
    • The DMM in AC mode will give rms value when the average is 0.
      • When the average of the signal is not 0, the DMM will first eliminate the mean and then find the rms value. This gives the deviation around the mean value.
        • You go through the same process when you want to find the value of the standard deviation.
        • For example, in problem 1 of the practice final, when the square waveform is 3V p-p with DC offset 1, then the waveform will alternate between the values -0.5 V and +2.5 V. When you sqaure this, the waveform has two values: 0.25 and 6.25. The average of the squared values is 3.25. The rms value is then around 1.8.
          If you use DMM in AC mode, you will get 1.5. This is because the mean (which in this case is the DC offset) is eliminated. Hence, you only have the square wave goes from -1.5 V to 1.5 V. Then, the rms value is 1.5.
        • More example: For Asin(x)+D above, our DMM in ac mode will give A/sqrt(2).
        • For this class, when you are asked to measure the rms value (as in the first problem of the practice final), simply use the DMM in AC mode.
          • Keep in mind that it is the rms value with the mean already eliminated.
      • This elimination of the mean is the same as what the oscilloscope displays in its ac coupling mode.
      • If DMM in DC mode gives x and DMM in AC mode gives y, the actual rms value can be found by sqrt(x^2 + y^2).
        • For example, in problem 1 of the practice final, the real rms value is sqrt(1^2 + 1.5^2) = 1.8 which agrees which what we found earlier.
    • Open-circuit (output) voltage of the function generator is its voltage output when there is nothing connected to it except the measurement device (DMM or oscilloscope).
      • When the question says "keep this value", it may also say "do not adjust anything on the function generator". In practice, you may have to double-check to make sure that the open circuit voltage is at the indicated value (by disconnecting the generator from the circuit and re-measure its voltage). You may also have to check that the waveform is of the correct shape. For example, if you are asked to use sinusoidal wave, usually the function generator may change back to triangular wave. In which case, you will need to adjust it back to sinusoidal.
    • Resistance measurement must be done when the resistor is not connected to the rest of the circuit.
      • If you have already built the circuit, take the resistor out, make the measurement, and then put it back into the circuit.
  • Final Exam Information
    1. 9:15AM-10:30AM
    2. 10:45AM-12:00PM
    3. 1:30PM-2:45PM
    • Check the following list for your exam time.
    • The practice problems for the final exam is posted. It is the same as the one that was distributed on the first lab session except the first page.
    • There are 8-10 questions.
    • Do not expect the TAs to help you or debug your circuit. They are not told not to do so.
      • You may ask for a new equipment/tool/bench.
  • Midterm scores. (The first column is the last three digit of your ID.)
  • Midterm Information
    • Here is the first page of the exam. Including this cover page, the exam has 7 pages.
    • There are 7 questions.
      • 57 points for Part A and 42 points for Part B.
      • Part A has two questions each has several sub-questions.
    • You have 75 minutes to complete the exam.
    • There are three groups (time slots) for taking the exam. You can find your exam time from this schedule.
    1. 9:00AM-10:15AM
    2. 10:30AM-11:45AM
    3. 1:30PM-2:45PM
    • The practice problems for the midterm exam is posted. It is an actual exam from the previous year. You can try part A of this practice on Dec 9. [Posted @ 4PM on Dec 1]
    • Do not expect the TAs to help you or debug your circuit. They are not told not to do so.
      • You may ask for a new equipment/tool/bench.
    • Record at least two decimal places from the DMM. Do not write 12 mA when you see 12.00 mA on the DMM’s display.
    • The following lecture notes from ECS303 may be helpful.
  • Welcome to ECS304! Feel free to look around this site. [Posted @ 11AM on Oct 26]

General Information

Calendar with Handouts and Course Material

Date

Experiments

November 11, 2009

L0: Introduction

November 18, 2009

L1: DC Measurements

November 25, 2009

L2: Network Theorems I

December 2, 2009

L3: Network Theorems II

December 9, 2009

R1: Review & Practice Session

December 16, 2009

E1: Midterm Exam

December 23, 2009

Mid-term Examination Period (No classes)

December 30, 2009

No Class

January 6, 2010

L4: AC Measurement

January 13, 2010

L5: Resonance RLC Circuits

January 20, 2010

L6: Diodes and Rectifiers

January 27, 2010

The 37th University Game 2009 (No classes)

February 3, 2010

L7: Operational Amplifiers I

February 10, 2010

L8: Operational Amplifiers II

February 17, 2010

R2: Review & Practice Session

February 24, 2010

E2: Final Exam

  • To give you some idea of of what we expect you to learn in this class, the practice problems for the final exam are given here. Throughout the semester, refer to these problems and make sure that you can answer all of them.

Calendar



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