Averaging out a Square Wave via circuitry?

Question

So I have a square wave that needs to be averaged. The wave varies between approximately +2.5V and +5V, while the other square wave ranges between 0V and +2.5V. NOTE: Both waves have a frequency falling withing the scope of 1 to 112 Hz.

How would I go about independently averaging these two waves out via circuitry? EX: The first waves average would be +3.75 and the second waves about +1.25V as time approaches infinity.

In the past I was told to use a high/low pass filter depending on the scenerio; however, this does not seem to work very well (neither nor both). Is there another simple method that could be done to average these waves out? How?

Answer 1

Basically, the sum of the averages is the same as the average of the sum. So, you can sum the inputs together then integrate the result using a low-pass filter (aka an integrator).

You could do this with one op-amp. Use a positive summing function (like a mixer) with a low-pass feedback for the averaging.

Answer 2

A low pass is definitely what you want.  If the lowest frequency is really 1 Hz, you need a very low frequency low pass, probably with a fc of 0.1 Hz, which means they would take many seconds to settle.

I'd use opamps and lots of RCs.

http://en.wikipedia.org/wiki/Low_pass_fi...

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