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Article #1893Re: High side driving N-channel Mosfet with PWM
From: Phil in Melbourne
Date: Tue, 06 May 2008 02:03
Date: Tue, 06 May 2008 02:03
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"terryc" <newssixspam-spam@woa.com.au> wrote in message news:pan.2008.05.06.00.23.14.139680@woa.com.au... > On Mon, 05 May 2008 21:24:43 +1000, Phil in Melbourne wrote: > >> I want to PWM a whole lot of LEDs. The current consumption of the bank of >> LEDs is in the order of 15 Amps, at 12V. > > Can you explain why you can not just break this down into multiple units > all centrally driven? say 15 units drawing 1amp each, or 30 units drawing > 500mA? It would be less convenient, but that is possible, and may end up being the way I go. There are motor controllers on the market that PWM high current motors. I thought it would be reasonably trivial to do seeing as MOSFETS come in high current versions, and seeing that LEDs don't have as much inductance as motors do. I will go for the MAX621 and suck it and see. If the fet overheats, I will decrease the PWM frequency. If it still overheats, I will break up the supply into groups of 3A loads. No big deal either way.
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X-Google-Thread: 112d1e,23a05bb8461714c3 X-Google-Thread: 103407,23a05bb8461714c3 X-Google-Attributes: gid112d1e,gid103407,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: arc1-ca.pugleaf.net!g2news1.google.com!news1.google.com!border1.nntp.dca.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!news1.optus.net.au!optus!newsfeeder.syd.optusnet.com.au!news.optusnet.com.au!not-for-mail From: "Phil in Melbourne" <reply@tonewsgroup> Newsgroups: sci.electronics.design,aus.electronics References: <481eee7b$0$17511$afc38c87@news.optusnet.com.au> <pan.2008.05.06.00.23.14.139680@woa.com.au> Subject: Re: High side driving N-channel Mosfet with PWM Date: Tue, 6 May 2008 12:03:08 +1000 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.3790.3959 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.4133 X-RFC2646: Format=Flowed; Original Lines: 28 Message-ID: <481fbc5d$0$17510$afc38c87@news.optusnet.com.au> NNTP-Posting-Host: 220.237.143.44 X-Trace: 1210039389 17510 220.237.143.44 X-Original-Bytes: 1806