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arduino upgrade with lm358p failure

Posted: 08 May 2021, 05:01
by paven
Hi y'all, i was building an arduino, I decided to upgrade and try the 'Buffered Voltage Bias circuit'. I have limited knowledge of op amps so i asked on the arduino forum for advice on a like which op amp to use, then I was advised to try an [https://www.ti.com/lit/gpn/lm358b]LM358P[/url], but im getting readings of over 400V from the circuit. Does anyone know if the op amp i have can be used with an altered circuit (in which case, what do i need to change?) or have i been wrongly advised that this op-amp can be used as a replacement? Any guidance would be greatly appreciated.

To be more detailed, I made the circuit up on my breadboard replicating the one described in this site. (i used a 1uf capacitor and 20k resistors for R3 and R4). I am running the circuit on 5V. I adjusted the pin numbers for the different op-amp using only one channel. The output is stable, and reading over 400v ( i've tried the circuit twice in very short runs from fear of damaging something, one first attempt and then a re-try when id checked everything again, i should have recorded the actual figure i think 418.something Volts). Does this give any further clues as to what's going wrong?