Reply-To: "Kevin Aylward"
From: "Kevin Aylward"
Subject: Re: Historical question: negative feedback and the op amp
X-Newsreader: Microsoft Outlook Express 6.00.2800.1106
Date: Wed, 13 Nov 2002 10:07:39 -0000
NNTP-Posting-Date: Wed, 13 Nov 2002 10:07:51 GMT
"Ban" wrote in message
> "Mike" schrieb im Newsbeitrag
> > 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
> > 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
> electronic circuit has been using feedback since the beginning of the
> Rather the main idea is to combine a functional block in one unit,
> requires some kind of integration.
> Feedback in itself is more a cure for the unlinearity and other
> shortcomings, nowadays it is no more needed,
Jesus wept dude. How you can claim this is pretty amazing really.
Feedback is most certainly a very usefull device, and imo, will *always*
> digital circuits work so
> precise, they do not require feedback.
But digital systems still use feedback, e.g. digital filters. Feedback
control systems are indispensable, analog or digital based. Without a
feedback temperature control system you would be dead.
>Feedback is an antique thing,
Sure is, so is the wheel.
> wasts power and a *lot* of speed. It is just a crutch not something we
> should cherish.
I don't why you say this. Sure using analogue feedback has some
negatives, but in most cases the advantages easily outweigh the
disadvantages. Try and make a reliable fixed gain of 100 without
feedback. This whole concept is not even debatable. Feedback is one of
the most important pieces of science around.
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.