I need to rectify an audio signal (max 4.8Vp-p)...and I'd like to get the maximum DC representation of this signal.
Ok, so if you type in precision full wave rectifier into Google, it sems best in class (or perhaps I should say most popular), is the Rod Elliot one here...
Simple Precision Rectifier (figure 6)
but the thing is, Rod uses dual rail opamps -my situation is limited to single rail - 5V. So I create a virtual ground at +2.5V & then use the same circuit but just running all those ground connections in Rod's circuit to my virtual ground. For a 4.8Vp-p input I get about 2.4V full wave AC output - all is good so far.
But as I say, extracting the DC component out of that signal will only give about 2V, So I need to amplify this full wave AC signal *but* also clamp/base the lower part of the waveform to ground - therefore what I want to achieve is a 0 thru 5V(ish) swing. So I messed about with Multisim & came up with this....
As you can see the output is about 3.6V DC - this is the best variant I can come up with (I'm not the best designer in the world - designing circuits being fairly new to me).
So ...has anyone got a better circuit or if not could some be so kind as to outline how to extract the maximum DC from an incoming signal of 4.8V peak to peak? (for a single 5V supply)
Many thanks
Ok, so if you type in precision full wave rectifier into Google, it sems best in class (or perhaps I should say most popular), is the Rod Elliot one here...
Simple Precision Rectifier (figure 6)
but the thing is, Rod uses dual rail opamps -my situation is limited to single rail - 5V. So I create a virtual ground at +2.5V & then use the same circuit but just running all those ground connections in Rod's circuit to my virtual ground. For a 4.8Vp-p input I get about 2.4V full wave AC output - all is good so far.
But as I say, extracting the DC component out of that signal will only give about 2V, So I need to amplify this full wave AC signal *but* also clamp/base the lower part of the waveform to ground - therefore what I want to achieve is a 0 thru 5V(ish) swing. So I messed about with Multisim & came up with this....
An externally hosted image should be here but it was not working when we last tested it.
As you can see the output is about 3.6V DC - this is the best variant I can come up with (I'm not the best designer in the world - designing circuits being fairly new to me).
So ...has anyone got a better circuit or if not could some be so kind as to outline how to extract the maximum DC from an incoming signal of 4.8V peak to peak? (for a single 5V supply)
Many thanks
Last edited:
Not sure what went wrong with that image file, let's try again...
An externally hosted image should be here but it was not working when we last tested it.
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