Designed and 3D printed the cutest little rack ears for this router

I decided I'd like to graph the mains power frequency over time. To do that, I need to safely collect data from the mains.

Using a low-voltage isolating transformer (no physical connection to mains wiring) as input, I built this surprisingly simple circuit that generates a pulse every time the mains frequency completes one cycle.

From circuit simulation to real-world implementation!

Next step: set up a digital chip to measure the timing of the pulses and derive a frequency value.

As an example of the kind of events that might be recorded via this circuit: this is the Australian mains frequency on the 13th of February 2024, when a catastrophic storm in Victoria knocked out power to 530,000 customers and left half the state without power.

World's Most Terrifying Power Supply has been cleaned up and given a new set of cables.