Ideas on how to split a 2V sine wave into separate negative and positive waves?

[drdanke]

I'm trying to design an audio circuit, where a 2V peak to peak sine wave (no dc offset) needs to be split into the separate top and bottom halfs of the wave, negative and positive, for further processing.

How would this be possible?  I've tried diodes (as the voltage drop would be acceptable), but the common ground on the separate outputs, has the signals coming back together, and the sine wave is a little distorted at 0V.  Is it possible, to separate the negative and positive halves of the waves, and then put them back together?

My other idea is possibly using a tiny center tapped 1:1 transformer?

I'm fairly new to electronics, so I apologize if this is an elementary issue I'm asking about.  Pointing me in the right direction would be all I need, so then I can do the technical research myself.

Thanks!

[Vgkid]

What about using 2 ideal half wave rectifiers. One set up for the positive  half, the other for the neg half.

[drdanke]

Thanks, nice info.  I googled that and found op amp based high-precision diode half wave rectification.  Definitely something I will throw on the breadboard and check out on the scope after doing more research.

[Keicar]

I think you could implement this using a single op-amp, even - with two feedback paths, each containing a diode biased in either direction.

[Dave]

This exact question was posed less than a month ago.

Here's my solution.

[drdanke]

Thanks Dave, this solution does seem to fit my needs nicely, and thank's for showing a complete circuit in Ltspice so I can see it implemented.  Seems like all I need to change will be to delete the bottom half, mirror the top part, with reverse diodes for the negative wave half.

[danadak]

Here is a single OpAmp sign changer thats clever, see attached.



Regardsm Dana.

[Dave]

Thanks Dave, this solution does seem to fit my needs nicely, and thank's for showing a complete circuit in Ltspice so I can see it implemented.  Seems like all I need to change will be to delete the bottom half, mirror the top part, with reverse diodes for the negative wave half.

Oops, seems like I haven't read your requirements carefully.
The OP of the thread I linked wanted both half-waves to be positive. I only now read that you want both to keep their respective polarities, just have them separated.

Copying the top part of my circuit and flipping the diodes will essentially give you the solution that Vgkid suggested.