Talk:Operational amplifier applications

Stuff copied here from op-amp page in preparation.

Neural nets

Op-amps have applications as artificial neurons in neural nets. Specifically, as a number of summer amplifiers attached to a central amplifier attached to a comparator or schmitt trigger. For details, see http://www.rgu.ac.uk/files/chapter10%20-%20implementing%20ANNs.pdf

Super Diode

The correct term for this cct is Ideal Diode. The term super suggests something thats actually better than a diode. This term super diode is not used in electronics (not that Ive heard of) and should therfore be changed to ideal diode.--Light current 17:44, 29 September 2005 (UTC)

It is actually better than a diode.  :-)

I've seen the terms "super diode" and "precision diode" and simply "precision half-wave rectifier". The latter is the most accurate. I haven't seen it called an "ideal diode". (Oh wait. Here is one example.)

[1] [2]

This should be at Talk:Super diode, anyway. — Omegatron 19:26, 29 September 2005 (UTC)

the ideal diode, as the name says, is something ideal that does not actually exist: it has a threshold of 0V and can bare tensions up to $-\infty$ without letting any current pass through. The super diode has a behaviour that is very similar to the ideal one, but it's threshold is about $0.7/10^{7}$ (that is small, but not zero), and the range of voltages it can bare is not unlimited. Alessio Damato 15:22, 7 October 2005 (UTC)

Exactly. I think "precision rectifier" is a "less slangy" term. — Omegatron 18:24, 7 October 2005 (UTC)

CAn we change it then to precision rectifier?--Light current 19:36, 7 October 2005 (UTC)

Yes it is better than a diode. Its ideal but not super-- which would imply-- well Im not sure what it implies. I should have said better somehow than an Ideal diode. The term super as applied to electronics/electrical engineering (apart from superconductor) is outside my professional experience -Light current 22:11, 29 September 2005 (UTC)

Op amp o/p impedance

THis statement seems to convey very little useful info. I think its wrong anyway. I will delete unless it can be tightened up--Light current 01:15, 30 September 2005 (UTC)

Expunged useless stuff--Light current 18:05, 12 October 2005 (UTC)

Recent edits by Fresheneesz

Generally, we want to cover opamp circuits the way they are used, not as variations of a universal configuration, so I'm not sure these recent edits are that helpful. Maybe you could put something like that in the differential amplifier article, showing the connection between diff amps and all the other varieties? (I did the same thing with a "universal transistor amplifier", and it's not a great idea. See Talk:Common collector, for example.)

Although the use of HTML to represent math in articles is somewhat contentious, using complicated HTML to simulate the same effect as TeX is definitely bad, and mixing both within the same equation is very bad. Can you restore them to TeX? — Omegatron 04:16, 2 November 2005 (UTC)

I edited the op amp page because the edit would have helped me in my ECE class if it were there when I first looked it up. You said that "Generally, we want to cover opamp circuits the way they are used" - however obviously we can't go through every permutation of an op amp circuit - we need general cases to consolidate knowlege into learnable peices. I rearranged the page because it showed very clearly that some circuits were special cases of the differential circuit. So not only does it show the special cases now, but it shows where the special cases come from more clearly than before. My goal for this page is to display a even more general op amp circuit so that you can use one equation for any op amp circuit consisting of resistors and power supplys. Fresheneesz 23:14, 8 November 2005 (UTC)

So I guess it depends on what our goal for this article is. Is it a teaching tool or a reference?

I doubt it's a great teaching tool, anyway. The problem with using a "universal amplifier" to teach all the various permutations is that the student won't recognize the permutations when they see them later. I was taught transistor amplifiers by saying that all the various types were variants on a universal transistor amplifier and I didn't learn them that well. I tried to add this to the various articles like common collector and it was (rightly) removed. I'm not sure this is a great idea.

We should probably just show both renditions of the same circuits, or maybe move the universal diff amp stuff to the differential amp article, and leave this one as a reference. — Omegatron 15:42, 9 November 2005 (UTC)

Well, I see what you're saying. And I do take wikipedia to be a reference not a "learning tool" - despite the fact that you can learn a huge amount from reading reference material. The thing is, here, the article still keeps all the diagrams of - and explanation for - the circuits that were previously displayed as stand alone circuits. However it adds the element of some being permutations of others. So students using wikipedia to learn about op amps will see not only the specific differences between non-inverting, inverting, and differencing amplification circuits, but can also generalize the equations and be able to more easily remember how an op amp works. In my experience, I've found that one hard-to-learn equation beats out learning many small equations - you'll always be doing more work learning the many small equations. I think adding the permutations to the differencing amplifier page would be much more obscure - I know I wouldn't look for equations about an inverting amplifier in the differencing amplifer page. Fresheneesz 02:47, 10 November 2005 (UTC)

But all of these circuits are permutations of each other. It's just a matter of perspective. You say that the inverting amp is a simplification of the differential amp; I say that the differential amp is a combination of a voltage divider and an inverting amp. Which of us is right?

I'm going to remove those bits and leave it the way it was before; categorized by topology only. (So the only simplifications of the differential amp are the ones that have certain resistor values, but still the same layout.) — Omegatron 16:11, 21 February 2006 (UTC)

Important note: headers in use

In some other encyclopedias this material is splitted into several articles. To generate cross-language links, the header references are used (for instance, . Please avoid changing the headers without the real need. Audriusa 20:38, 2 January 2006 (UTC)

en:Operational amplifier applications#Differentiator

Hole in page

We should include Breakpoint generators here.--HappyEater 16:40, 19 May 2007 (UTC)

Typos in document

In the explanation for the non-inverting amp, the resistor subscripts don't correspond to the picture. "A third resistor, of value R_\mathrm{f} \| R_\mathrm{in}, added between the Vin source and the non-inverting input, while not necessary, minimizes errors due to input bias currents."

"Differential Amplifier"

I have often noticed a tendency to confusion around this term. I believe the usage is to call this circuit with an opamp and two matched pairs of resistors, a "Difference Amplifier". "Differential Amplifier" is the term used to name the input stage inside the opamp, as you will see if you follow the link to that article. 144.232.138.222 (talk) 22:53, 18 June 2008 (UTC)