Path: utzoo!mnetor!uunet!husc6!bbn!oberon!cit-vax!cit-vlsi!flaig
From: flaig@cit-vlsi.Caltech.Edu (Charles M. Flaig)
Newsgroups: sci.electronics
Subject: Re: switching amplifiers
Message-ID: <5303@cit-vax.Caltech.Edu>
Date: 24 Jan 88 04:35:14 GMT
References: <3539@megaron.arizona.edu>
Sender: news@cit-vax.Caltech.Edu
Reply-To: flaig@cit-vlsi.UUCP (Charles M. Flaig)
Organization: California Institute of Technology
Lines: 28


In article <3539@megaron.arizona.edu> wendt@arizona.edu (Alan Lee Wendt) writes:
>Is it possible to build an amplifier just like you would build a
>switching power supply?  Except that instead of feedback circuitry
>to maintain level dc, change the feedback so that the output is
>maintained at whatever the input is, times 1000.  What would such
>a beast be good for?
>
>Just curious,
>Alan Wendt

I took a class a couple years ago on switch-mode power supplies, and was
interested in building a high power switching audio power amplifier.  The
class texts were authored by Middlebrook and Cuk, and published by Tesla
Inc. (or something similar).  There is a series of three books, and at 
least one of them had details on using bidirectional Cuk switching circuits
for such an audio amplifier.  I built half of a single channel for the
lab part of the course and encountered no problems, but never seemed to
get around to building the complete amplifier. :-(

In general, such a switching amplifier can be used whenever high efficiency
and high output power is needed.  They are excellent for low frequency
amplification, but you have to be careful with high frequencies (such
as audio) since the response depends on the switching frequency and the
filtering circuits, among other things....

--Charles Flaig
  flaig@csvax.caltech.edu