Hey, here is a simple diagram to show "what it is now" vs "what I want" in the design.
I used the x81 factor divider considering the full 400V, even if the whole drop happens across R1 (which will never be the case) the ADC will get <5V in its input.
But it is a problem when the voltage drop is less(eg 0.4V). So now I am thinking of using different resistor pairs as dividers and use mosfets(or simillar) to switch them from highest to significant lowest as in autorange systems to measure VR1.
But doing this may have an effect in accuracy, not sure how much? In kelvin connections the wire resistance doesn't matter - can I use something like that here?
Also if this design could work, I will need help in the gain / filter / amplifier stages.
Please check the attachments and give response.
Thanks.
Edit: I don't mind if my design is totally bad or is not suitable for this purpose. So don't try to go through this design and make it work somehow. If I get any idea that will work better, like Allan sir suggested, the complete analog devices sitting at the high voltage levels, i can go through that as well. I just don't like to work on high voltages, that's probably why I considered dividing and then amplifying to get to the results. Please see how it can be done. Thanks again.
