Op amps
- Read my explanation of input and output impedance, and Lectures 10-12 from my Phys 222 Lecture Notes. Read Experiments 9 and 10 in Meyer's lab
manual. If you wish, complete the Reference
Reading indicated at the beginning of each of these experiments.
- Complete the Procedures in Experiments 9 and 10 in Meyer's manual. Additional instructions:
- Even
though the follower circuit is first, I recommend that you do this part
last. (For all the other circuits, you're asked to do
measurements that can be explained entirely by the golden rules.
The follower circuit is the simplest circuit, so the manual uses
this circuit to investigate the more complicated op amp properties of
slew rate, open-circuit gain, and input and output impedance.)
- For
the integrator circuit, in a single graph, plot both measured and
theoretical gain as a function of frequency for sinusoidal inputs.
Apply a square wave at a single frequency, and compare the
measured amplitude of the output with theoretical prediction.
- For the differentiator circuit, in a single graph, plot both measured and
theoretical gain as a function of frequency for sinusoidal inputs.
Apply a triangle wave at a single frequency, and compare the measured
amplitude of the output with theoretical prediction.
- Build an op amp current source: establish a fixed current through a resistor
connected between the power supply and the correctly chosen op amp input. Place the "load" (a variable
resistor) between the same input and the output. Predict and measure the current through the
load when the load resistance is in the "good" range. Predict and measure this range.