Spoerle
Junior Member level 3

I have a 30-year-old construction in which I use classic panel ammeters for 200uA to measure AC voltage and AC current.The measured current is 0-200uA on the order of 100kHz. Voltage 0-20mV, both AC more or less sine symmetrical around 0.
I will not state any requirements for accuracy, in the old design it was like this: the operator watched the meter and turned the potentiometer until the needle showed what the operator wanted.
In the new design, the operator is replaced by an MCU and, depending on what the ADC measures, it turns a digital potentiometer.
What I'm solving is how to complicate life as little as possible. The MCU has a 12bit 1MSPS ADC and so theoretically it's enough to separate the measured signal, amplify it and shift it from +- to 0-2.5V and solve the rest with SW, ADC. Another option is to convert AC to DC, True RMS, etc.This is not commonly done and so I don't know what the path of least resistance is.How would you solve it?
I will not state any requirements for accuracy, in the old design it was like this: the operator watched the meter and turned the potentiometer until the needle showed what the operator wanted.
In the new design, the operator is replaced by an MCU and, depending on what the ADC measures, it turns a digital potentiometer.
What I'm solving is how to complicate life as little as possible. The MCU has a 12bit 1MSPS ADC and so theoretically it's enough to separate the measured signal, amplify it and shift it from +- to 0-2.5V and solve the rest with SW, ADC. Another option is to convert AC to DC, True RMS, etc.This is not commonly done and so I don't know what the path of least resistance is.How would you solve it?