I need to determine whether a pump motor is running, and use that to trigger an ESP32.  As luck would have it, the next day a colleague at work mentioned needing something similar for his home automation system.  So, I created a video to describe the operation of the initial circuit that I created.

The current transformer shown is the CR8410-1000 from CR Magnetics.

Here’s the schematic:

This diagram includes the optional filter capacitor (in orange) shown in the video, this smooths out the waveform of the signal going into the ESP32.