Voltage follower.

[sl50]

Hi all,

I have a quick question. We all know how an opamp voltage follower works, but I am wondering since all the close loop feedback is negative to stablize the system, and keeps it from oscillating, but what about a positive feedback voltage follower. Is there any difference between the negative feedback voltage follower and a positive feedback voltage follower, and will the positive feedback voltage follower oscillate or become unstable?

Thanks for the help.

 

[Diver300]

An op-amp wired with it's non-inverting input to the output will have the output permanently at one extreem or the other.

It then becomes a schmitt trigger. To make a more useful schmitt trigger it is more common to only have some positive feedback, by using two resistors to devide the feedback voltage. That moves the switch points closer together.