Op-amp integrator and differentiator in real-life

[Kruum]

I've gone through some light theory on op-amps and can understand that fully. What I don't understand are the real-life applications for integrator and differentiator. What does the output signal looks like? Can somebody shed some light on these?

 

[skeptic2]

Try this...
http://en.wikipedia.org/wiki/PID_controller

 

[Bob S]

If you use an inverter configuration op amp with a resistor R in series with the neg input and a feedback capacitor C from the output to the neg input, it is an integrator. Put a square wave in and get a triangle wave out. If you put occasional pulses V volts high and T sec wide in, the output will be proportional to the input voltage V divided by R times pulse width T divided by capacitance C.

If you replace the input R with a capacitor, and use a feedback resistor instead of a capacitor, you will get positive and negative spikes out (differentiated signal), good for triggering scalers, etc.

 

[Proton Soup]

if you integrate a constant, you get a ramp. and that you could use to deflect an electron in a CRT to draw a horizontal line, and to gradually move that line a little lower vertically each sweep.

maybe about as interesting as vacuum tubes with today's technology, tho.

 

[Kruum]

Thanks for the replies guys! I can't wait to be able to put theory into practise. All these sound like gold, espescially the PID controllere sounds something I'm going to need quite a lot.

 

[likephysics]

You can also use them to calculate velocity, & position from accelerometer.