Questions about emontx schematic (two burden resistors and one resistor in series)

I have been reviewing the emontx electronic scheme (to better understand its operation), and I have found several issues that I would like if someone could clarify.

  1. I have seen that there are 2 burden resistor in parallel … is that correct? Is it to get a non-standard resistance value?

  2. In the connection to the ADC pin there is a resistor of 1k connected in series with the burden resistors, what purpose does this resistor have?


There is only one SMT burden resister fitted per CT channel (3x 22R + 1x 120R channels), the “alternate” through hole burden resisters are not populated and the holes are there for the purpose of modifying the burden values.

The 1K resisters are just there to protect the ADC inputs.

And it is not in series with the burden, but in series with the ADC input.