darrins Posted July 28, 2004 Report Share Posted July 28, 2004 I have a couple of basic questions related to a differential amplifiers. If these types of questions are better suited to the Theory Articles board, please let me know. :)I want to amplify the voltage difference between a sensor (Vs) and a reference voltage (Vref). I only want to amplify this signal when there is a positive difference, i.e. Vref - Vs > 0. Otherwise, I want the output to be zero (ground). If I just connect a standard diode to the output of the amp, will this do the trick? Or, is there a better technique.Another question. I've seen differential amplifiers called "Instrumentation Amplifiers" where the two imput signals are fed through voltage followers (or buffer amplifiers) before being feed to the differential amp. I have no common mode carrier signal to remove (they are both DC voltages). Is there any advantage to using this so-called instrumentation amplifier vs. a standard differential amp for my application? I have plenty of quad op-amps, so that's not a problem.Last question. I want to calculate the average voltage coming from 3 or 4 different sensors. I know this can be done usign what is called a "passive averager" circuit (see below). This can also be done using a summing op-amp by selecting appropriate values of resistors. Is there any advantage to the op-amp approach?Thanks.Darrin Quote Link to comment Share on other sites More sharing options...
ante Posted July 28, 2004 Report Share Posted July 28, 2004 Darrin,It Quote Link to comment Share on other sites More sharing options...
darrins Posted July 28, 2004 Author Report Share Posted July 28, 2004 Ante,Funny you should post that. I just downloaded the same paper yesterday, but the one you posted looks more recent. I guess I need to stop being lazy and just read it. :-[ Looks like a good paper from what I've read so far.Thanks.Darrin Quote Link to comment Share on other sites More sharing options...
ante Posted July 28, 2004 Report Share Posted July 28, 2004 Darrin,I did not insinuate that you are lazy, that was your own words. ;D ;D Here is more for your E-Book shelf!Ante ::)More_on_OP-Amps.zip Quote Link to comment Share on other sites More sharing options...
darrins Posted July 28, 2004 Author Report Share Posted July 28, 2004 Thanks. I'll add it to my collection. ;D Quote Link to comment Share on other sites More sharing options...
login
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.