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- Newsgroups: sci.electronics
- Path: sparky!uunet!infonode!ingr!b30news!catbyte!medin
- From: medin@catbyte.b30.ingr.com (Dave Medin)
- Subject: Re: 12 V -> 3V, 0.6 A
- Message-ID: <1992Nov10.192023.6010@b30.ingr.com>
- Sender: medin@catbyte (Dave Medin)
- Reply-To: medin@catbyte.b30.ingr.com
- Organization: Intergraph Corporation, Huntsville AL
- References: <sehari.721280522@class1.iastate.edu> <1992Nov9.114833.26094@bernina.ethz.ch>
- Date: Tue, 10 Nov 1992 19:20:23 GMT
- Lines: 38
-
- In article <1992Nov9.114833.26094@bernina.ethz.ch>, schaerer@isi.ethz.ch (Thomas Schaerer) writes:
-
- |> Sorry but all this is nonsense bcause of the high current. If you realise
- |> a linear regulator you will generate very high lostpower. In this example
- |> will be 0.6A * 9V = 5.4W. The better way is to build a switched regulator.
- |> The advandage is the high efficiency ang therefore less powerdissipation.
- |> There are many ic which can do this with a few additional components.
- |> Take the Switching-Regulator L296 from SGS-THOMSON. There is a kit with
- |> pcb-board and the needed components. Ask a SGS-THOMSON-Distributor.
-
- The poster is right about the power dissipation, but the idea is not
- a good one for audio devices (which the first poster was inquiring
- about). The high frequency garbage and ripple (even from converters
- operating in the 100 KHz to 1 MHz region) wreaks havoc on audio
- circuitry both through direct amplification and also detection as
- RF. This is, unless the supply is carefully designed and installed.
- The L296 (of which I have the evaluator kit mentioned) holds no
- special cards in the noise department.
-
- My CD player (Philips/Maggotbox) is a good example of switch mode
- technology in audio. The logic and transport have a very heavily
- filtered switching supply, while the analog split supply is linear.
- It works well.
-
- I've had incredibly bad luck with switching supplies and audio. I'd
- caution others to avoid possibly wasting time with it.
-
- --
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