Subject: Re: Historical question: negative feedback and the op amp
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Date: Wed, 13 Nov 2002 16:37:52 -0800
NNTP-Posting-Date: Wed, 13 Nov 2002 16:47:38 MET
Organization: @Home Network
"fred bartoli" wrote in message
> Ban a écrit dans le message :
> > "Mike" schrieb im Newsbeitrag
> > news:hBnA9.5273$XF5.email@example.com...
> > > Harold Black came up with his negative feedback theory in 1927, yet
> > > first op-amp wasn't invented until the 1950s.
> > >
> > > The op-amp seems like such a natural extension, once you know about
> > negative
> > > feedback. Why did it take so long for the op-amp to come along?
> > >
> > > -- Mike --
> > >
> > >
> > I do not think OpAmps come from the negative feedback idea, nearly every
> > electronic circuit has been using feedback since the beginning of the
> > aera.
> > Rather the main idea is to combine a functional block in one unit, which
> > requires some kind of integration.
> > Feedback in itself is more a cure for the unlinearity and other
> > shortcomings, nowadays it is no more needed, digital circuits work so
> > precise, they do not require feedback. Feedback is an antique thing, it
> > wasts power and a *lot* of speed. It is just a crutch not something we
> > should cherish.
> Are you saying that you're able to build a flipflop without (positive)
> feedback ?
> Or building the clock oscillator without feedback ?
> Or that IIR filters are not being used anymore ?
Or that humans don't use feedback to speak, walk, drive a car, write etc??
None of that is possible without feedback.