Hello DrDiettrich
DrDiettrich:
Provided that the other frequencies have a low amplitude only, you could filter the signal in hardware or software, then take the peak value and compute the RMS value from it.
I think this will be possible, is the a way to do this within the Arduino Due? Something like a build in FFT maybe?
DrDiettrich:
Using PWM may distort the primary current further, so that a linear current source can be required.
This is why I want to use the analog output (12 bit, 4096 steps). This resolution can be doubled by using only positive flanks (as in my picture posted above). The current source itself provides a full d.c. current based on the voltage input (programmable, e.g. 1 V input -> 10 A output).