Return-Path: Received: from fed1rmmtao03.cox.net ([68.230.241.36] verified) by logan.com (CommuniGate Pro SMTP 4.2.4) with ESMTP id 455576 for flyrotary@lancaironline.net; Wed, 06 Oct 2004 19:58:04 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.36; envelope-from=daveleonard@cox.net Received: from davidandanne ([68.111.224.107]) by fed1rmmtao03.cox.net (InterMail vM.6.01.03.04 201-2131-111-106-20040729) with SMTP id <20041006235733.KVLW25647.fed1rmmtao03.cox.net@davidandanne> for ; Wed, 6 Oct 2004 19:57:33 -0400 From: "DaveLeonard" To: "Rotary motors in aircraft" Subject: RE: [FlyRotary] Re: #$!%@$ temperatures still high Date: Wed, 6 Oct 2004 16:57:34 -0700 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0057_01C4ABC5.93944010" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 In-Reply-To: Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_0057_01C4ABC5.93944010 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Al, you are right about now having the lack of over-voltage protection. All I have in line is a fusable link rignt now. Fortunately, all of my expensive avionics can tolerate voltages of at least 28V without being affected. If a voltage regulator fails, how high can the voltage go? Dave Leonard Dave; That's interesting. Makes me wonder whether I should put a scope on voltage and see if it is smooth. The downside of connecting the field to the output, as I'm sure you know, is that you now have the risk of a runaway voltage condition if the VR fails. I guess the odds are low, but the costs could be high. Avionics? I assume that you have a breaker (or fuse) in the alt field circuit. You can put a "crowbar" circuit between the field lead and ground that will trip the breaker in an over-voltage condition. I got one from Aeroelectric. Al ------=_NextPart_000_0057_01C4ABC5.93944010 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
Al, you are right about now having the lack = of=20 over-voltage protection.  All I have in line is a fusable link = rignt=20 now.  Fortunately, all of my expensive avionics can tolerate = voltages of at=20 least 28V without being affected. 
 
If a voltage regulator fails, how high can = the voltage=20 go?
 
Dave Leonard

Dave;

 

That’s = interesting.  Makes me=20 wonder whether I should put a scope on voltage and see if it is = smooth. =20

 

The downside of connecting the = field to=20 the output, as I’m sure you know, is that you now have the risk = of a runaway=20 voltage condition if the VR fails.  I guess the odds are low, but = the=20 costs could be high. Avionics?

 

I assume that you have a = breaker (or=20 fuse) in the alt field circuit.  You can put a = “crowbar” circuit between=20 the field lead and ground that will trip the breaker in an = over-voltage=20 condition.  I got one from Aeroelectric.

 

Al

 

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