X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 09 Feb 2008 18:43:10 -0500 Message-ID: X-Original-Return-Path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.123] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with ESMTP id 2722258 for lml@lancaironline.net; Sat, 09 Feb 2008 07:58:48 -0500 Received-SPF: none receiver=logan.com; client-ip=71.74.56.123; envelope-from=schaefer@rts-services.com Received: from Master.RTS-Services.com ([70.113.90.126]) by hrndva-omta03.mail.rr.com with ESMTP id <20080209125809.IJPD1575.hrndva-omta03.mail.rr.com@Master.RTS-Services.com> for ; Sat, 9 Feb 2008 12:58:09 +0000 Received: from RTSLaptop (cpe-70-113-90-126.austin.res.rr.com [70.113.90.126]) (authenticated bits=0) by Master.RTS-Services.com (8.13.1/8.13.1) with ESMTP id m19Cs18V014378 (version=TLSv1/SSLv3 cipher=RC4-MD5 bits=128 verify=NO) for ; Sat, 9 Feb 2008 06:54:01 -0600 From: "Richard T. Schaefer" X-Original-To: "'Lancair Mailing List'" Subject: RE: [LML] Voltage Regulator Power Draw X-Original-Date: Sat, 9 Feb 2008 06:57:47 -0600 X-Original-Message-ID: <001c01c86b1b$5ee823e0$680aa8c0@RTSLaptop> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001D_01C86AE9.144DB3E0" X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 In-Reply-To: Thread-Index: AchqjpSJ+9IBkFawRROvlXhYQdS/AgAiAcUg X-Spam-Score: -1.552 () AWL,BAYES_00,DYN_RDNS_SHORT_HELO_HTML,HTML_MESSAGE,RDNS_DYNAMIC X-Scanned-By: MIMEDefang 2.58 on 192.168.10.101 This is a multi-part message in MIME format. ------=_NextPart_000_001D_01C86AE9.144DB3E0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit It's not a constant current. The variable current supports the field winding of the alternator and is proportional (at a fixed RPM) to the amount of current the Alternator must deliver to the buss. It uses more current after initial start and tapers off when the battery recharges. The minimum current is going to be a function of the load (number of other devices) that you are running. So a better question might be to ask: What is the regulator current draw when the Alternator must deliver a steady state load of 8A at cruise RPM ? I picked 8A as a guestimate for nominal night IFR load. I have no idea what the answer is! I am not sure it's important to know the nominal current for the Regulator. You typically want to know current loads so you can figure your endurance when the alternator does not work. No alternator . than you can turn off the alternator field load. You want to know the max current so that you can wire and fuse appropriately. The LR-3 WILL short it's input to ground on an over voltage detection to trip the alternator circuit breaker. It is important that you properly fuse this. _____ From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of rwolf99@aol.com Sent: Friday, February 08, 2008 2:14 PM To: lml@lancaironline.net Subject: [LML] Voltage Regulator Power Draw Does anyone know how much current an LR-3 voltage regulator draws to drive a 40 amp alternator in a 12 VDC system? Not how big a fuse to use, but how much current does it use? Thanks in advance... - Rob Wolf _____ More new features than ever. Check out the new AOL Mail ! ------=_NextPart_000_001D_01C86AE9.144DB3E0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

It’s not a constant = current.

The variable current supports the = field winding of the alternator and is proportional (at a fixed RPM) =

to the amount of current the = Alternator must deliver to the buss.

It uses more current after initial = start and tapers off when the battery recharges.

The minimum current is going to be = a function of the load (number of other devices) that you are = running.

So a better question might be to = ask:

What is the regulator current draw = when the Alternator must deliver a steady state load of 8A at cruise RPM ? =

I picked 8A as a guestimate for = nominal night IFR load. I have no idea what the answer = is!

I am not sure it’s important = to know the nominal current for the Regulator.

You typically want to know current = loads so you can figure your endurance when the alternator does not work. =

No alternator … than you can = turn off the alternator field load. You want to know the max current so that = you

can wire and fuse = appropriately.

The LR-3 WILL short it’s = input to ground on an over voltage detection to trip the alternator circuit = breaker.

It is important that you properly = fuse this.

From: = Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of rwolf99@aol.com
Sent: Friday, February = 08, 2008 2:14 PM
To: = lml@lancaironline.net
Subject: [LML] Voltage = Regulator Power Draw

Does anyone know how much current an LR-3 voltage regulator = draws to drive a 40 amp alternator in a 12 VDC system? Not how big a fuse = to use, but how much current does it use?

Thanks in advance...

- Rob Wolf

More new features than ever. Check out the = new AOL Mail!

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