The drop in dc bias voltage | Electronics › Electronics › Measure 330V ac with microcontroller › The drop in dc bias voltage July 23, 2014 at 11:06 am #11927 AJISH ALFREDParticipant The drop in dc bias voltage is due to the parallel effect of R2 and R3 across R5. To avoid this use a significantly high valued resistor for R3, around the range of 100K. Hope this will solve the issue. Please try and update
