Path: utzoo!mnetor!uunet!mcvax!diku!dde!mbe
From: mbe@dde.uucp (Martin Berg)
Newsgroups: sci.electronics
Subject: Re: switching amplifiers
Message-ID: <144@Giraf.dde.uucp>
Date: 26 Jan 88 13:26:14 GMT
References: <3539@megaron.arizona.edu>
Organization: Dansk Data Elektronik A/S, Herlev, Denmark
Lines: 25
Summary: Switching amplifiers

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?

Some years ago, Sony made an amplifier (type identification ?) where
the output transistors where driven in on/off mode (i.e. a switching
output stage).
I think they called it 'Class D' operation.

The main idea was to minimize the power loss in the amplifier (just
as in a switching power supply).

The result was (as far as I can remember) that the ratio between
output power and input power (messured from the 220V (110V :-) )
AC input) was as high as 63 %. Normal amplifiers (domestic) has a
ratio about 50 %.

Kind regards

Martin Berg (Dansk Data Elektronik A/S)

..mcvax!diku!dde!mbe    or   mbe@dde.UUCP