Hi all,

i made a ckt which can detect the voltage for a cell(very common using differential opamp).i placed each ckt on each cell.and connected cells in series.
now the problem is, ckt is giving proper value of cells only when number of cells are 6 or less than 6.as soon as i am exceeding the number of cells more than 6 , the ckt does not give proper value of vltage..
to power up the ckt , i used vrps and all the ckts are connected in parallel.

can any one help me in this regard.

 

Hello,

I found this thread in "the completed projects" forum.
That forum is ONLY for completed projects.
There it will stay invisible.
I moved it over here and made it visible, so others can give replies.

Bertus

 

There is no schematic, no power supply and no parts list.

 

You might guess that when enough cells are added in series, the total voltage of the battery they make up exceeds the span that can be accommodated by the circuit inputs, especially given that the description seems to say they are powered by a common supply.

We will probably never know though.

 

You might guess that when enough cells are added in series, the total voltage of the battery they make up exceeds the span that can be accommodated by the circuit inputs, especially given that the description seems to say they are powered by a common supply.

We will probably never know though.

I bet it's gone out of the common mode range of the op-amp since it's only got a single rail.