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Article #1356Re: Tingles from power supply
From: Eeyore
Date: Tue, 10 Mar 2009 22:45
Date: Tue, 10 Mar 2009 22:45
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2289 bytes
john@jjdesigns.fsnet.co.uk wrote: > So, based on the above notes, I'm reading that this capacitor is > purely there for the manufacturers benefit!. It is fitted to help kill > off the nasty HF noise that naturally couples across via C strays from > the transformer primary to secondary. You got it. > Essentially, the manufacturer generates the sodding switched mode > noise in the first place then has no alternative but to find some > method of filtering their rubbish out of the floating DC secondary. > Only means they have is the naff bridging capacitor, which results in > the leaking AC, the tingles and the sparks in the dark. > Ban the damned things, that's what I say :) > Ps. My wall wart that blew some kit up had a Varistor fitted instead > of that cap!. I wonder if that was an accidental fit. I've seen reels with the occasional wrong value on them but to get a varistor in place of a cap would be very odd. How did it pass Q/C ? Graham
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X-Google-Thread: 112d1e,5985c699c60fb1f8 X-Google-Thread: 103407,5985c699c60fb1f8 X-Google-Attributes: gid112d1e,gid103407,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: arc1-ca.pugleaf.net!g2news1.google.com!news3.google.com!feeder3.cambrium.nl!feed.tweaknews.nl!83.80.28.12.MISMATCH!multikabel.net!newsfeed10.multikabel.net!news.astraweb.com!border2.a.newsrouter.astraweb.com!not-for-mail Message-ID: <49B6ED9C.2A3C15BE@hotmail.com> Date: Tue, 10 Mar 2009 22:45:48 +0000 From: Eeyore <rabbitsfriendsandrelations@hotmail.com> Organization: Eeyore's gloomy place X-Mailer: Mozilla 4.8 [en] (Windows NT 5.0; U) X-Accept-Language: en MIME-Version: 1.0 Newsgroups: sci.electronics.design,aus.electronics Subject: Re: Tingles from power supply References: <00b89736$0$7237$c3e8da3@news.astraweb.com> <pan.2009.03.09.20.20.12.51572@example.net> <49B590CB.7145F087@hotmail.com> <3cc53687-b529-4c4e-908e-a727fefd5c9f@y13g2000yqn.googlegroups.com> <49B5C6D5.B77ACD34@hotmail.com> <73697af8-4169-472d-abeb-dc61210dad77@l16g2000yqo.googlegroups.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 27 NNTP-Posting-Host: cbadf371.news.astraweb.com X-Trace: DXC=L1KEZU`=abFMnc]O[a9m]EL?0kYOcDh@JgP=YS3P0dAFaQ3M>fcN^7LYS`@2JBI2kKjad1;GlU1cL4@Tdc=]j>6E