I am trying to create an input circuit for the ADC of the arduino. It is being fed an audio source in the range of 0-10V (or 20Vpp max) so I want to divide this down to the 0-5V range, rectify it and filter it a bit.
Below is the circuit I am planning to use. Do you see anything wrong with it? (quite a lot borrowed from stuff Garrett Mace posted on the topic of VU meters).
The opamp is rail to rail and powered on 0-5V. So do I need any kind of over voltage clamp (like a Zener?) I am guessing no since it will not be possible for this op amp to put out more than the rail which is 5V.
The input trimmer is to divide the incoming audio by approximately 4 to bring it into range (since the op amp gain will be 2).
The TLV2372 is kind of expensive so maybe it is cheaper to use a TL072 (powered with 12v) and 5.1V zener instead?