Reliable method to measure high AC voltage

Thread Starter

Xavier Pacheco Paulino

Joined Oct 21, 2015
726
Hello,

What would be a reliable method to measure AC voltages up to 600V with a microcontroller? Is it better to rectify the voltage and use a voltage divider as I usually see?
 

dl324

Joined Mar 30, 2015
8,870
That's probably what I'd do. Pay attention to the maximum working voltage for the resistors you use.
 

danadak

Joined Mar 10, 2018
3,573
Do you need galvanic isolation ? What accuracy and resolution do you need ?


Regards, Dana.
 
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Janis59

Joined Aug 21, 2017
767
1) And what frequency is expected? Methods for 50 Hz and 50 GHz will happen be reciprocal, probably.
2) re:""Pay attention to the maximum working voltage for the resistors you use"". Just be warned the SMD has between 50V and 200V and even the most powerful 2W full size resistors has between 350 and 500 V (few yet 750V). So the long stacks are unavoidable. But where are stacks there are parasitic inductance. Surplus to it like good-will-killer there are thermal power ie current limits, so the resistance will gonna be big indeed. But for big resistances an impact of porous and/or surface layer humidity effects are more than large.
3) And if to take in consideration such damn thingy as parasitic capacitance.....
 
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