Yes, I finally managed to get an op amp to differentiate an input potential that varies over time.
The top trace is the input potential. The bottom trace is the output from the op amp, showing the first derivative of the input. Huzzah!
I connected the differentiator circuit to a sinusoidal input potential, and after some fiddling with the y-gain I was able to see the output potential. As you can see, the circuit is differentiating correctly!
I’ve recorded a video, but I’ve not finished playing yet so I won’t upload it until I’ve done a bit more.
Physics with Keith 