X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from relay01.roc.ny.frontiernet.net ([66.133.182.164] verified) by logan.com (CommuniGate Pro SMTP 5.0c2) with ESMTP id 718161 for flyrotary@lancaironline.net; Sun, 11 Sep 2005 02:00:33 -0400 Received-SPF: pass receiver=logan.com; client-ip=66.133.182.164; envelope-from=canarder@frontiernet.net Received: from filter04.roc.ny.frontiernet.net (filter04.roc.ny.frontiernet.net [66.133.183.71]) by relay01.roc.ny.frontiernet.net (Postfix) with ESMTP id 0CB4136418E for ; Sun, 11 Sep 2005 05:59:49 +0000 (UTC) Received: from relay01.roc.ny.frontiernet.net ([66.133.182.164]) by filter04.roc.ny.frontiernet.net (filter04.roc.ny.frontiernet.net [66.133.183.71]) (amavisd-new, port 10024) with LMTP id 00869-01-95 for ; Sun, 11 Sep 2005 05:59:48 +0000 (UTC) Received: from [127.0.0.1] (unknown [70.98.128.118]) by relay01.roc.ny.frontiernet.net (Postfix) with ESMTP id A4DEC36416E for ; Sun, 11 Sep 2005 05:59:48 +0000 (UTC) Message-ID: <4323C7CB.7030503@frontiernet.net> Date: Sun, 11 Sep 2005 00:59:39 -0500 From: Jim Sower User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040514 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Overvoltage control (help Ed A) References: In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-Antivirus: avast! (VPS 0536-5, 09/09/2005), Outbound message X-Antivirus-Status: Clean X-Virus-Scanned: by amavisd-new-2.3.2 (20050629) at filter04.roc.ny.frontiernet.net Since there's six diodes in the rectifier, we're talking SEVEN issues. Have you ever done this on an oscilloscope? Wouldn't shorted diodes cause 3-phases of AC that largely cancel each other so that you end up with the ripple you always have on top of your DC output now ripple above zero Volts? Inquiring minds need to know ... Jim S. By sunup we'll be into a record setting FOURTH DAY of PVORT ... Jim S. Finn Lassen wrote: > Two different issues. > 1) Voltage regulator failure feeding full voltage to the field winding > making the alternator put out as much as it possibly can, probably 90 > or more volts if not prevented by battery load. > > 2) Shorting of one or more of the rectifier diodes in the alternator > which might result it in putting out an AC voltage, but more likely > result in no output. > > Finn > > Tim Andres wrote: > >> I could be wrong but I don’t believe the rectifiers are going to be >> found anywhere but in the alternator. Moving to an external regulator >> will not affect their environment. >> >> Tim Andres >> >> ------------------------------------------------------------------------ >> >> *From:* Rotary motors in aircraft >> [mailto:flyrotary@lancaironline.net] *On Behalf Of *Jim Sower >> *Sent:* Saturday, September 10, 2005 5:49 PM >> *To:* Rotary motors in aircraft >> *Subject:* [FlyRotary] Re: Overvoltage control (help Ed A) >> >> Finn Lassen wrote: >> >> I suspect that the regulators in our alternators are very >> reliable, providing they are adequately cooled. That would be one >> advantage for having a external regulator: it can be mounted in a >> cooler location. >>