Hi everyone:
I'm now very confused about whether or not the series resistance is compensated automatically with current-clamp mode in Multiclamp 700B.
I heard that a circuit called "bridge-balance circuit" was previously used to compensate for the series resistance, but that was not done automatically before. But now I also read that the circuit is built-in in many modern amplifiers and is functioning automatically with current-clamp mode.
I'm now convinced that this circuit is functioning automatically because when I inject current into the cell there's no component of series resistance, which should induce a constant increase from baseline all over the injection period. Please see the attached figure.
Maybe I'm asking some stupid questions, but I'm looking forward to your answers! Thank you!
Dear Yao,
welcome,
Without entering in the details of the multiclamp 700B, if you inject current in your cell and your cell has a series resistance, then the overall voltage of the cell will be like the top figure containing an abrupt a voltage step IRs, with I is the injected current and Rs the series resistance of the cell. If IRs is cancelled the output will be only the slowly rising part of the cell voltage pointing out slow charge build up.
So, you are right and i confirm your vision.
These problems are fine ans sophisticated not trivial. If they are trivial you would get many answers.
Best wishes
Hi Zekry:
Thank you very much for your answer.
I also calculated the membrane resistance, if the series resistance isn't compensated and is subtracted from total input resistance, then the membrane resistance will be too low for a cell. So from this point, I think that Rs is really already compensated.
Best
- Badges
- Science topic
- Similar topics
- Engineering
- Chemical Engineering
- Membranes