(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Please, I would like to know how to find the factor by which the capacitance is multiplied

A picture of the Op Amp is here: http://en.wikipedia.org/wiki/File:Cap-mult-op.svg

Zc is complex impedance of C

2. Relevant equations

none given

3. The attempt at a solution

choose,

I2 through R2 left to right

I1 through R1 top to bottom

so Iin = I1+I2 = (Vin-Vout)/R2 + Vin/R1 +Zc

Vout =V- = V+ = (ZcVin)/(R2+Zc)

...

Iin=Vin((R2+R1)/(R1(R2+Zc)))

And then I'm not sure how to calculate the effective capacitance. I think it is supposed to be increased by a factor of R2/R1 but I dont know how to get that.

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Op Amp Capacitance multiplier

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**