Honestly I'd be surprised if any standard ADC would be able to handle AC.
I'm doing a lot with electronics but never saw an ADC that was able to
handle AC directly.
May i suggest to take a look at the ESPeasy wiki:
https://letscontrolit.com/wiki/index.ph ... Converters
I've written that text to explain the basics of how an ADC works.
The way an ADC works will unavoidably result in strange random values.
The circuit you suggested is obvously made for an Arduino or AVR CPU with a
specialized software that can even detect phase shifting between voltage and
current to calculate effective power and the power factor (cos phi).
ESPEasy ahndles a lot of things internally and will be far too slow to handle
such a project.
Another hint:
To make things easier I'd avoid the SCT013-030 converters with built-in resistor.
Use a similar type with a current output like "20A/20ma" or similar,
not with
an output voltage like "20A/1V"
Types like this:
https://www.aliexpress.com/item/1900375496.html
or maybe the SCT006:
https://www.aliexpress.com/item/32681520192.html
The SCT006 has the advantage of easy mounting, but the disadvantage of a very low.
Why is that better?
The voltage output types give a defined
AC voltage that must be rectified for measurement.
The diode rectifiers have a voltage drop of at least 0,3..0,4 V so measuring low current will
give bad or no result at all. For exact measurement it needs e rectifier electronic using a
precision OpAmp and some parts around it.
If you use a current type transformer, it's the current that counts. The current goes through the
diodes and a resistor giving a rectified but still pulsing voltage. The two resistor-capacitor circuits
R2/c1 and R3/C2 build a low pass filter to give a "straight" DC for measurement.
Nonestly it's not the best way in a scientific sense, but the easiest way to handle pure current
measurement with a DIY circuit.
I've created a circuit for this.
Warning! This is not tested and might need further tweaking!
.
- Rectifier Circuit.jpg (188.17 KiB) Viewed 42294 times
.
As you said the space in the compartment is small, here's an example design:
.
- Rectifier_PCB.jpg (210.53 KiB) Viewed 42294 times
It's about 6 x 3 cm² and just a fgew millimeters high.
