I hope there are some EEs in here

[Mikealot]

I'm currently working on a lab report, and it was an Op-Amp lab, and the question is about applications. Could you guys help me out, some specific examples of when an inverting configuration is useful and when a non inverting configuration is useful.

 

[TuxDave]

Can you draw a picture of each of the configurations for me? I can't recall what they look like. In the meantime, that's a pretty broad question. Are you asking for real life applications? Or just some simple circuit topologies where they are used?

 

[Mikealot]

im talking real life. An inverting configuration has the signal attached to the negative terminal, and a non-inverting has it connected to the positive terminal. The implication is that an inverter has negative gain, resulting in a negative output voltage, whereas the non-inverting configuration has positive gain for a postitive output voltage. The question is supposed to be broad, I'm asking for very general applications.

 

[TuxDave]

Oh... um... I guess you have to be a little creative for this. For the inverting configuration I GUESS you could build some noise cancellation device. So the input is the outside noise and an inverting op-amp with a gain of 1 would output the inverted sound sample. Plug it into some headphones and you get a sound cancellation headphone?

Non-inverting.... umm... gimme a sec. I'm trying to think of something that you NEED a non-inverting setup.

 

[Mikealot]

well non inverting is easy, any amplification is done with noninverting... i mean, realistically, inverting simply amplifies as well, i just need some application I can simplistically explain

 

[bobsmith1492]

You could just use it as a simple microphone preamp....

We haven't analyzed op amps YET in linear circuits, but we're getting there I've used them a lot and always as preamps for an audio circuit.

 

[TuxDave]

Originally posted by: Mikealot
well non inverting is easy, any amplification is done with noninverting... i mean, realistically, inverting simply amplifies as well, i just need some application I can simplistically explain

Yeah, but I was assuming you wanted to find something that a non-inverting amplifier could do but an inverting amplifier cannot.

 

[f95toli]

There is no way to give a real answer that question unless you go into some rather "advanced" electronics.

Both configurations can be used in almost any application and both have advantages and drawbacks. Inverting or non-inverting usually only matters in DC applications and then only if you are not using a floating ground (in which case you can simply interchange the cables and get any polarity of the signal), an inverting configuration will shift the phase of an AC signal by 180 degress but usually you do not care.

In order to see a "real" difference you need to consider things like input and output impedance, noise and slew-rate.

So it is a strange question if you ask me.

 

[imgod2u]

Non-Inverting opamps give positive feedback and is usually used in generating an oscillating signal. Inverting opamps are usually just amplifiers that take in a signal and amplifies it. Voltage followers, filters, etc. all use inverting amplifiers.

 

[TOTA42]

Originally posted by: imgod2u
Non-Inverting opamps give positive feedback and is usually used in generating an oscillating signal. Inverting opamps are usually just amplifiers that take in a signal and amplifies it. Voltage followers, filters, etc. all use inverting amplifiers.

That's not really true, Non-inverting opamps do not give postive feedback. Positive feedback is where you take the opamp's output and connect it to the non-inverting input of the Opamp and negative feeback is where the output is fed back into the inverting input. What you're talking about is negative and postive feedback. Small but significant difference. I spent three weeks in a circuits class thinking they were the same thing. The only case where I can think of a decent use of Non-inverting amplifers is when you try to make an instrumentation amplfier. In this case it has two non-inverting amplifiers and a differential amplfier. This is commonly used in biomedical instruments.

 

[imported_jediknight]

The only real difference between an inverting op amp and a non-inverting op amp is the "inverting" part.. otherwise, they both have the same applications, essentially.
Most common use is simply as an amplifier, for:
- stereos
- sensors (photo, temperature, pressure.. anything)
- repeaters (ie. signals lose power when transmitted.. and if transmitting over long distances, need to boost the signal)

Another use in a lab I did was as a noise regulator (wrong term.. but that's how I'll describe it). Ever notice how some tv shows are much quieter than the LOUD commercials? By using op amps (and some more circuitry), you can essentially set a maximum volume level.. I forgot how it works, but I believe it utilizes the range where an op amp no longer amplifies..