band stop filter with single supply .

[basantab]

Hello

I had this simple band stop filter schematic and modified to work (supposedly) with single supply by putting 1.5 volt offset .
Except that it doesnot work.

Is that correct way of offsetting the final stage ?

In simulation too it does not work if i input offset voltage of 1 volt and 1 volt peak to peak signal riding on it.
It works in simulation it works if i put any voltage without offset.

In reality it doesnot work with offset voltage input.

Idea is not to get inverting voltage (negative) from final stage so adding offset i thought might bring voltage up above the ground..

Is there anything more i should look into ?

(also i have been playing around with other types of config like twin-t notch and other active filter)
thankyou

[Circlotron]

I think the 1.5 volt bias going into the last opamp is the wrong polarity.
Also, the bottom of the input resistor on the lower opamp should go to +1.5V, not ground.
Further, I think you have created a band stop filter, not a band pass.

[basantab]

thanks my bad i wanted to say bandstop filter

and last part of opamp is summing amplifier(modified) so that the output is not negative ..I donot know if its possible that way to modify.
but i will check with the polarity again thankyou.

and regarding earlier stage opamps they are just a voltage follower so is that high pass section requires offset also? (due to cap blocking dc offset and ac passing and single supply cannot buffer ac)?

thankyou

[Circlotron]

and regarding earlier stage opamps they are just a voltage follower so is that high pass section requires offset also? (due to cap blocking dc offset and ac passing and single supply cannot buffer ac)?

Yes.