Return-Path: <bdube@al.noaa.gov>
Received: from tomcat.al.noaa.gov ([140.172.240.2] verified)
  by logan.com (CommuniGate Pro SMTP 4.2)
  with ESMTP id 391304 for flyrotary@lancaironline.net; Fri, 03 Sep 2004 10:33:52 -0400
Received-SPF: none
 receiver=logan.com; client-ip=140.172.240.2; envelope-from=bdube@al.noaa.gov
Received: from PILEUS.al.noaa.gov (pileus.al.noaa.gov [140.172.241.195])
	by tomcat.al.noaa.gov (8.12.0/8.12.0) with ESMTP id i83EXLuB023185
	for <flyrotary@lancaironline.net>; Fri, 3 Sep 2004 08:33:21 -0600 (MDT)
Message-Id: <5.2.1.1.0.20040903082403.027ec080@mailsrvr.al.noaa.gov>
X-Sender: bdube@mailsrvr.al.noaa.gov
X-Mailer: QUALCOMM Windows Eudora Version 5.2.1
Date: Fri, 03 Sep 2004 08:33:41 -0600
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
From: Bill Dube <bdube@al.noaa.gov>
Subject: Re: [FlyRotary] alternator LED
In-Reply-To: <list-391286@logan.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 09:15 AM 9/3/2004 -0500, you wrote:
>Hi, all.  I just returned from Autozone, where I purchased a package of 3
>red LED's meant for automotive use. They came pre-assembled with an inline
>resistor that has shrink tubing around it, so I can't tell what colors are
>on the resistor. My assumption was that since it is made for automotive use,
>it might be OK to use for my alternator warning LED indicator?

         I don't know what alternator and regulator you are using, but on 
some cars the warning light was an important part of the circuit. When you 
would turn the keyswitch to the "on" position, current would flow from the 
keyswitch, though the bulb, to the regulator to tell it to turn field 
windings on. If the bulb was burned out, the alternator would not come on. 
LEDs have a tiny current compared to a bulb. An LED might not flow enough 
current to turn on the regulator.

         Of course, there are many different regulators and many different 
types of alternator circuits, so this may not be an issue for you.