I'd whipped the attached up earlier in Circuitmaker Student, which is obsolete/no longer supported, but has a smattering of IC's and transistors that have been popular over the last 30 years or so.

It's different from what RonH came up with, but I suppose that's to be expected - there's always a number of different ways to skin the proverbial cat.

One problem you may run into with this version is the average input voltage; if there's a very long string of "10101010.." that eventually changes to "010101..", the waveform won't be centered around the 0v level; it'll be centered around the average voltage level whereas ideally it should be centered on P-P/2.

This version also doesn't allow for differences in threshold levels for the comparators; it depends upon the higher slew rate from the amplified signal to trip the comparators in a reasonably short amount of time.

 

Thank you very much, this looks good. I'm going to order the parts today. I'll be keeping you posted to let you know how it worked out. What software did you use to draw up that schematic? And also can it emulate the circuit? I need to see about purchasing some software that can because I believe it would greatly shorten my learning curve.

Edit: Aren't both of these amps doing the same thing on this circuit? I mean shouldn't one of them be reversed in order to spit out an inverted yet amplified wave? I could be completely wrong but I'm just curious.

The first amp has a gain of 51. You might need to change the gain. The second amp has a gain of -1, so the output is the inversion of the first amp's output.

I used LTspice from Linear Technology to create the schematic. LTspice is totally free and uncastrated, and I think is really good, but, as with all good software, it has a learning curve. The simulation is slightly different from the schematic I posted. It is included in the attached zip file, along with the spice models for the op amp and the comparator. If you decide to install LTspice, let us know if you need help running the simulation.

 

The first amp has a gain of 51. You might need to change the gain. The second amp has a gain of -1, so the output is the inversion of the first amp's output.

I used LTspice from Linear Technology to create the schematic. LTspice is totally free and uncastrated, and I think is really good, but, as with all good software, it has a learning curve. The simulation is slightly different from the schematic I posted. It is included in the attached zip file, along with the spice models for the op amp and the comparator. If you decide to install LTspice, let us know if you need help running the simulation.

Hi Ron;

I just downloaded and installed LTspice last night. Any suggestions of how best to help deal with the learning curve? I noticed that the help section did have some learning steps and examples, but wondered if there are any tutorials from say a first year engineering course or such?

 

Hi Ron;

I just downloaded and installed LTspice last night. Any suggestions of how best to help deal with the learning curve? I noticed that the help section did have some learning steps and examples, but wondered if there are any tutorials from say a first year engineering course or such?

I think you can find what you are looking for in the LTspice Yahoo Group. You may have to join the group, but it's free. If you click on "links" on the left side of the page, it will point you to tutorials, as well as a lot of other useful-looking information. I have never tried any of them.
You can also search the messages, which I do occasionally, and generally find what I am looking for.

 

I think you can find what you are looking for in the LTspice Yahoo Group. You may have to join the group, but it's free. If you click on "links" on the left side of the page, it will point you to tutorials, as well as a lot of other useful-looking information. I have never tried any of them.
You can also search the messages, which I do occasionally, and generally find what I am looking for.

Thanks, I also joined that Yahoo group last night, but didn't explore it. I'll check it out.

Thanks again

 

Hmm. Well I accidently ordered soic 2272's so I'm stuck using the non r-2-r 324's. My current problem is that the positive signal is coming in fine but the negative signal is not being amplified and/or rectified. I am not supplying a negative rail to this op amp so doing a simple gain of -1 on the original signal results in nil. :\

 

Hmm. Well I accidently ordered soic 2272's so I'm stuck using the non r-2-r 324's. My current problem is that the positive signal is coming in fine but the negative signal is not being amplified and/or rectified. I am not supplying a negative rail to this op amp so doing a simple gain of -1 on the original signal results in nil. :\

The 2272 won't swing below the negative rail either. What circuit are you using?