I am trying to read AC voltage with an Arduino to be able to detect parameters such as phase angle, peak voltage on load and source sides for comparision.
For this, I have a 230VAC to 15VAC transformer where I am using a voltage divider circuit using 10k and 2k 1/4 watt resistors for a 2.5VAC output which I am feeding straight into analog pin A1 of an Arduino Uno.
I have already built and tested the circuit and everyting seems to be working fine and I am ablhe to see a sine wave on thr Arduino plotter.
Before I finalize it and build a PCB for it, I was wondering if others can peruse through the description and circuit diagram below and let me know if there's anything critical that I may've missed. Mainly, can the circuit I've built be considered "safe" for the Arduino (as well other electronics connected to it,) or do I need to add protection elements like a polyfuse or Zener for over current and over voltage protection?
Simplified circuit diagram:
Waveform with approx 2.5V to -2.5V after mapping in the code: