How to extract the DC/average value across a capacitor in a series circuit?

[Teece]

Hi all.

This is a question that should have an easy answer, I suppose. I know that a
capacitor in a series circuit will store the average value of an arbitrary
waveform, in that there will be equal area above the average value and below
the average value. How would I extract this average value with analog
circuitry?

Thank You
Teece

 

[rebel]

Hi all.

This is a question that should have an easy answer, I suppose. I know that a
capacitor in a series circuit will store the average value of an arbitrary
waveform, in that there will be equal area above the average value and below
the average value. How would I extract this average value with analog
circuitry?

Without knowing more detail, and depending on the range of voltage present
across the cap, a buffer (op-)amp followed by a suitable low-pass filter is the
way I'd start looking at it.