15 - Inverting Differentiator

INTRO: Today we revisited the circuit element family of Op Amps. As a refresher an op amp is a circuit element that amplifies the values going into it. It is also capable of doing mathematical operations, as the name implies. Today we dealt with a specific type of Op Amp, the inverting differentiator.

Below is a diagram of an op amp circuit. The differentiator produces an output that is proportionally based off of the rate of change of the input. In other words, it is dependent on the derivative of the input signal. This is ideal since you know have the ability to change large amounts of voltage/current based off of much smaller changes of current/voltage.

LAB: INVERTING DIFFERENTIATOR
In this lab we will examine the forced response of a circuit involving an inverting differentiator. We will use varying frequencies for the input and measure the values at the output.

Below is a the pre-lab where we calculated values for the circuit. Our calculations involved the input voltage and calculating the output voltage that we should receive. We will compare these to our measured values when we set up our circuit.


Below is a picture of our circuit with or circuit elements connected per the lab instructions.


In the following graphs we used sine waves at 0.5, 1, & 2 Khz. Our calculated values were not too far off from our experimental data.

The following chart summarizes the values obtained from calculations and the experiment. At lower values our percent difference was 1.9, but it increased to around 5% at higher voltages. We are working with budget equipment, as well as with moderate knowledge of circuits, so I would say the percent difference is within the realm of our experiment.