Re: Sesning mains input current in offline SMPS
Thanks
If the sense resistor is placed just downstream of the mains rectifier bridge, (as in the attached schamtic) then it shouldn’t matter whether the sense resistor is placed in the [DC Bus –ve] or the [DC Bus +ve]. Either place should be equal from a noise point of view, since each node alternately connects to mains live then mains neutral.
However, even in this case, I always seem to see less noise when the sense resistor is connected into the [DC Bus –ve]. Do you know why?