output voltage i get with v2=8v, v1=4v is 4,2v and 4,4v for 2 output in lm358What output voltage do you get?
What is the power supply voltage for your LM358?
That's a LOT of offset. 5mV would be the maximum for an LM358 unless the gain resistors very large8-=4 is ~4, Which, in theory is correct if ideal. The real OP amp isn't ideal.
What non-ideal issues are causing problems?
i need to get accurate battery voltage to balance the battery pack8-=4 is ~4, Which, in theory is correct if ideal. The real OP amp isn't ideal.
What non-ideal issues are causing problems?
That's a LOT of offset. 5mV would be the maximum for an LM358 unless the gain resistors very large
There are obviously two circuits here - how are they connected?
What are the real voltages on the battery? I would doubt that they are both 4.000V
Yes you're correct, this circuits mesure the output of the top battery, and neither measures the output of the lower one.So both circuits measure the output of the top battery, and neither measures the output of the lower one?
Those offsets are rather more realistic and about what you could expect for a LM358 and 1% resistors.
If you need better accuracy (why?) then use an OP07 or TLV07 and 0.1% resistors.
by Aaron Carman
by Duane Benson
by Duane Benson