# analog circuit nodal analysis

I had difficulty in evaluating following circuit's node analysis to find the transfer function. I had difficulty because of the ground in the middle of the circuit and the way the source voltage is attached to circuit. I would be very happy if you can show how i should evaluate the node equations. Thank you very much. An RC twin T circuit like this will generally have the transfer function: - For the circuit below: - Even with R1 = R2 etc it's by no means a simple thing you are asking so I would say to you this...

Here's the answer (above) and it can be simplified to give the desired answer in your question, but where are you getting stuck i.e. how far have you got with solving this?

• thank you for the answer. Im stuck in writing node equation according to input voltage. will it be as following (Va-Vin)/r1 + Va*2cs+ (Va-V0)/R2=0 for the upper node and (Vb-vin9/cs + b/r2 + (vb-vo)/cs= 0 for the one in the below. if it would be like that, shouln't I need another equation to evaluate the transwer function? May 23, 2015 at 17:45
• Try looking down the page on this site: circuitplay.blogspot.co.uk/2014/01/the-twin-t-filter.html - it's not that easy of course. May 23, 2015 at 18:38
• Here's another that might be useful: niu.edu/~mfortner/labelec/lect/p575_07a.pdf May 23, 2015 at 18:41
• Also try this one: millersville.edu/physics/experiments/111/index.php May 23, 2015 at 18:42