Return-Path: Received: from email2k3.itlnet.net ([64.19.112.12] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 753111 for flyrotary@lancaironline.net; Mon, 21 Feb 2005 14:05:53 -0500 Received-SPF: none receiver=logan.com; client-ip=64.19.112.12; envelope-from=jwvoto@itlnet.net Received: from rav.itlnet.net (unverified [192.168.10.149]) by itlnet.net (Rockliffe SMTPRA 6.1.17) with SMTP id for ; Mon, 21 Feb 2005 13:05:07 -0600 Received: from JWVOTO (unverified [64.19.114.13]) by itlnet.net (Rockliffe SMTPRA 6.1.17) with SMTP id for ; Mon, 21 Feb 2005 13:05:05 -0600 Message-ID: <003f01c51848$b91992a0$0d721340@JWVOTO> From: "Wendell Voto" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Digital Fuel Monitoring System Date: Mon, 21 Feb 2005 13:07:45 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003A_01C51816.55E8E280" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 This is a multi-part message in MIME format. ------=_NextPart_000_003A_01C51816.55E8E280 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable > I have also been toying about building a "black Box" to monitor = things. Besides the fuel level monitor, outside temp, data from EMC2 = and such. I can program it but building the components is the = challenging stuff and that is why it interests me. As i feed the = airplane voltage into my application, I divide the current by 1/3 so = that I can feed my microchip ADC. In my prototype, I have been using 1M = resistors to do the division. Does it matter on the size? My thinking = is, since I only want to voltage, the higher the better. >=20 > Bob K Bob, Why not use a little 3 leg voltage regulator, no worry about resistors = heating or enough current to the ADC; grant it that an ADC draws = microamps. Will help keep out voltage spikes that can damage an ADC. = Then you can run other devices off the same regulator. The radio shack = ones have a schematic on the package. Can't go wrong. Wendell ------=_NextPart_000_003A_01C51816.55E8E280 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
> I have also been toying about building a "black Box" to = monitor=20 things.  Besides the fuel level monitor, outside temp, data from = EMC2 and=20 such.  I can program it but building the components is the = challenging=20 stuff and that is why it interests me.  As i feed the airplane = voltage into=20 my application, I divide the current by 1/3 so that I can feed my = microchip=20 ADC.  In my prototype, I have been using 1M resistors to do the=20 division.  Does it matter on the size?  My thinking is, since = I only=20 want to voltage, the higher the better.
>
> Bob K

Bob,
Why not use a little 3 leg voltage regulator, = no worry=20 about resistors heating or enough current to the ADC; grant it that an = ADC draws=20 microamps.  Will help keep out voltage spikes that can damage an=20 ADC. Then you can run other devices off the same = regulator. The=20 radio shack ones have a schematic on the package. Can't go=20 wrong.
Wendell
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