[time-nuts] Re: Another reason to monitor line frequency :) - My AC measurement project & question

[willl will]

Hi everyone,

I have an recently finished project that also measuring AC waveform, full
description here:
https://github.com/will127534/RaspberryPiAtomicNixieClock/wiki

Basically using an AC transformer and Ti's ADC8681 @ 50Khz sampling rate.

This year I'm working on a earthquake sensor + AC mains monitor system (In
an earthquake prone area, AC mains frequency will fluctuate by power
generator and machine emergency stop like this one:
https://twitter.com/kuriuzu/status/1360602496821911553).

I want to improve AC measurement. Apart from the ADC sampling speed upgrade
(previously bottlenecked by the SPI connection to FPGA). I'm currently
debating about whether or not to bypass the transformer. How does the
distortion of an AC transformer impact the accuracy of mains waveform and
frequency? I'm not sure if it is worth it to go through the mains voltage
safety requirements.

Thanks,
Will