X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost03.isp.att.net ([204.127.217.103] verified) by logan.com (CommuniGate Pro SMTP 5.3c3) with ESMTP id 4003091 for flyrotary@lancaironline.net; Fri, 04 Dec 2009 17:57:06 -0500 Received-SPF: none receiver=logan.com; client-ip=204.127.217.103; envelope-from=bbradburry@bellsouth.net Received: from desktop (adsl-157-63-125.mco.bellsouth.net[68.157.63.125]) by isp.att.net (frfwmhc03) with SMTP id <20091204225631H03000u3gfe>; Fri, 4 Dec 2009 22:56:31 +0000 X-Originating-IP: [68.157.63.125] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: Primer in AC/DC Electricity Date: Fri, 4 Dec 2009 17:56:35 -0500 Message-ID: <7A1C4456730743579EFC4B2B67102D76@Desktop> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002D_01CA750B.1F3111C0" X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6001.18049 Thread-Index: Acp1Ir1fJBDA39CESPeKUnQ1jYMvKgAEH2rQ This is a multi-part message in MIME format. ------=_NextPart_000_002D_01CA750B.1F3111C0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit George, He is probably not talking to folks who install an electrically dependant alternative engine. If you just forget the problems that might arise getting Tracy's controllers, etc, and the 12V auto starter to work on 24V, you still have to accept the fact that that "big 24V battery" can fail. If is does and you don't have a second battery, it will get very quiet in the cockpit until the screaming starts. Also don't forget that the only way you can get a 24V battery is to tie two 12V batteries together. If you go with one 24V battery, you have the same battery weight plus the weight of redundant busses. If you go with two batteries, you now have 4 times the weight of one 12V battery. If you try to mix the systems so you have 24V and 12V, you have a nightmare. The only real advantage seems to me to be wire weight (smaller wire for 24V). I am pretty sure that I ate more weight for last nights dinner than the entire wireing system in my plane :>) If you really want to save weight in your plane, go on a diet! (I don't want to hear that you are 7 feet tall and weigh 120 lbs! :>)) Bill B _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich Sent: Friday, December 04, 2009 3:45 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Primer in AC/DC Electricity Kelly, Being electronically challenged I had a quick look. It says 24 volts is better for aircraft use eliminating the need for extra batteries and alternator, I'm wondering why builders collectively don't already go that way. Are there complications or additional expenses to be considered or are auto conversions typically locked in to a 12 volt system for one reason or another - perhaps just the alternator. George ( down under) Group, Some of you may have already seen this and to others this may be knowledge that you carry around in your head and use everyday but to someone like me whose schooling in AC/DC (Navy) electricity was 50 plus years ago and also something I do not use everyday the following link has refreshed my old brain..............Hope some of the group finds it useful.............. http://www.eaa.org/experimenter/articles/0903_aircraft_wiring.pdf -- Kelly Troyer "Dyke Delta"_13B ROTARY Engine "RWS"_RD1C/EC2/EM2 "Mistral"_Backplate/Oil Manifold ------=_NextPart_000_002D_01CA750B.1F3111C0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

George,

He is probably not talking to folks who install an electrically dependant alternative engine.  If you just forget the problems that = might arise getting Tracy’s controllers, etc, and the 12V auto starter to work on 24V, you still = have to accept the fact that that “big 24V battery” can fail.  = If is does and you don’t have a second battery, it will get very quiet = in the cockpit until the screaming starts.  Also don’t forget that = the only way you can get a 24V battery is to tie two 12V batteries = together.  If you go with one 24V battery, you have the same battery weight plus the = weight of redundant busses.  If you go with two batteries, you now have 4 = times the weight of one 12V battery.  If you try to mix the systems so you = have 24V and 12V, you have a nightmare.

The only real advantage seems to me to be wire weight (smaller = wire for 24V).  I am pretty sure that I ate more weight for last nights = dinner than the entire wireing system in my plane  = :>)

 

If you really want to save weight in your plane, go on a = diet!  (I don’t want to hear that you are 7 feet tall and weigh 120 = lbs!  :>))

 

Bill B 

 

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich
Sent: Friday, December = 04, 2009 3:45 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Primer in AC/DC Electricity

Kelly,

Being electronically challenged I had a quick look. = It says 24 volts is better for aircraft use eliminating the need for extra = batteries and alternator, I'm wondering why builders collectively don't already go = that way. Are there complications or additional expenses to be considered or = are auto conversions typically locked in to a 12 volt system for one reason = or another - perhaps just the alternator.

George ( down under)

Group,

         Some of you may = have already seen this and to others this may be knowledge that you = carry

around in your head and use everyday but to someone like me = whose schooling in AC/DC (Navy) 

electricity was 50 plus years ago and also something I do not = use everyday the following link has

refreshed my old brain..............Hope some of the group finds = it useful..............

 

--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold


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