Hello everybody, I have a square wave duty cycle in a range of 10-90% and I need to construct a circuit which calculates "the mean value as an output" by only using circuit elements "R,L,C and op-amps". Digital elements and transistors are not going to be used. I need your help.

 

Hello,

Take a look at an "integrator".
Here is a page with some opamp schematics.
http://www.educypedia.be/electronics/analogopamptopics.htm

Greetings,
Bertus