Lab 9: Choose from a few different circuit options
Fri May 22, 2020 18:07
The goal of this lab is to learn how to independently design and build some more-complex circuits with little guidance. You can choose one option from a few suggested ideas described below, or you can develop your own idea for something with complexity similar to the suggestions. If you are working on an extra credit project, this is an opportunity to get started on it by building one or two stages of the larger circuit you are developing for that project, and getting credit for it in this lab as well as the extra credit.
If you want to go with an approach of your own design, you don't need to get approval for it from the instructor or TAs. Indeed, iterating on that would be an inefficient use of our time and defeat the point of the "independent design" goal. But, make sure that your approach is not just a repeat of circuits built in previous labs and that it is of similar complexity to the options below.
You should focus on doing carefull work and logging it fully. That is more important to your lab grade than how expansive of a project you do.
Outline: Prelab assignment, Voltage controlled oscillator, Napping alarm, Negative impedance converter Analog calculator, Measure op-amp imperfections,Prelab assignment
The prelab assignment is to choose what you plan to do and describe it briefly in an ELOG entry.Option 1: Voltage controlled oscillator
Build a voltage controlled oscillator and do something interesting with it.Potentially interesting things to do with it include:
- Set up a few switches to feed the oscillator different control voltages -- each from a voltage divider -- to play different tones.
- Obtain the oscillator's control voltage from a phototransistor so you can wave your hands over the circuit to "play" different tones.
- Obtain the oscillator's control voltage from a triangle or saw tooth wave so you can play a whooping sound.
Option 2: A napping alarm
Build a napping alarm similar to what you designed in the homework.Potentially interesting things to do with it include:
- Take a nap to verify that it works.
- Verify that the snooze feature also works by extending your nap -- you know, for the sake of science.
Option 3: Negative impedance converter
Build a negative impedance converter and confirm that it behaves properly for a few different options, such as: negating the V = IX relationship with the appropriate setup, changing the frequency dependence of a capacitor (use a Bode plot).
Option 4: Build an analog calculator
Build a circuit that will perform a few different calculations such as adding or subtracting two input signals (as in the quiz). Then add features that allow integrating or differentiating the outputs, all selectable with some push-buttons (or moving jumper wires).
Option 5: Measure the non-ideal properties of your op-amp
Measure an extensive set of the properties for your KA358 op-amp, such as :
- Slew rate
- How close the outputs can get to the rails
- Input offset voltage
- Input bias current
- Input and output impedance. (This will be hard, but you can at least determine that Xin is greater than some value and Xout is below some other value.)
- Power consumption