Return-Path: Received: from out011.verizon.net ([206.46.170.135] verified) by logan.com (CommuniGate Pro SMTP 4.2.8) with ESMTP id 611422 for flyrotary@lancaironline.net; Tue, 18 Jan 2005 09:00:37 -0500 Received-SPF: pass receiver=logan.com; client-ip=206.46.170.135; envelope-from=finn.lassen@verizon.net Received: from verizon.net ([4.12.145.173]) by out011.verizon.net (InterMail vM.5.01.06.06 201-253-122-130-106-20030910) with ESMTP id <20050118140006.FQIK4717.out011.verizon.net@verizon.net> for ; Tue, 18 Jan 2005 08:00:06 -0600 Message-ID: <41ED1663.90107@verizon.net> Date: Tue, 18 Jan 2005 09:00:03 -0500 From: Finn Lassen User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax; PROMO) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: New discovery... References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------050303040302010403000307" X-Authentication-Info: Submitted using SMTP AUTH at out011.verizon.net from [4.12.145.173] at Tue, 18 Jan 2005 08:00:06 -0600 This is a multi-part message in MIME format. --------------050303040302010403000307 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit That would definitely be an elegant solution. It would still see a current draw of maybe 10 to 20 amps for the fuel pumps, ignition coils and EC-2, but that would be nowhere near the 100 or 100's of amps the starter pulls which is what brings the starter battery to its knees. A thought -- there's no real reason to run both pumps during start-up, is there? Finn Bulent Aliev wrote: >David, I'm thinking more like a small 12V battery only for the avionics bus >protected by an isolator? So the starter won't pull it down, but the battery >will supply initial 12v to the computer. My starter even scrambles the EM2 >display if it's on. I'm not so good with electricity, but many of you here >are . >Buly > >On 1/18/05 12:26 AM, "David Carter" wrote: > > > >>Having lurked on the Aeroelectric List for years, 'Lectric Bob & his Z >>diagrams use a "Low Voltage" module (LVM) of some sort that turn on a "low >>valtage light" when alternator fails and voltage drops below "min voltage to >>charge a battery", something like 13.8v, with voltage regulator set for >>something just over 14 v so battery gets charged for sure. >> >>So, given that "data point", looks like it might be useful for us folks with >>"computer dependent" engines, which need 9v (for this particular ECU), to >>fabricate a second LVM (set for 9.1 or 9.3 v) that turns on a light - or >>voice warning - to tell us "voltage too low to start" (i.e., below ECU >>minimum voltage required to start). I'd probably put the light close to >>the starter switch. >> >>David >>----- Original Message ----- >>From: "Bulent Aliev" >>To: "Rotary motors in aircraft" >>Sent: Monday, January 17, 2005 10:24 PM >>Subject: [FlyRotary] New discovery... >> >> >> >> >>>For some time I was so proud my engine would start right away. The last >>> >>> >>time >> >> >>>on Friday night I started it few times and everything was fine. Came back >>>this morning and tried to start it again, no joy? For hours I tried >>>everything, plugs, coils injectors, everything was fine. Kept cranking, >>>fired once for a second and died again. Even starting spray didn't do it. >>>The last thing (lunch time) I measured the voltage while cranking and it >>> >>> >>was >> >> >>>9V. Ahaaa! I remembered something about the computer not working below 9V. >>>I hooked the charger and went for a long lunch with the airport bums..Came >>>back in 3 hrs and BINGO! started right away many times. >>>So the moral of the story is (I think?). If you have enough power to crank >>>the engine, does not mean that it will start. The starter pulls down all >>> >>> >>the >> >> >>>available juice and the computer takes a break. Any comments? >>>Buly >>> >>> >> >> > > > > > >>> Homepage: http://www.flyrotary.com/ >>> Archive: http://lancaironline.net/lists/flyrotary/List.html >>> >>> > > > --------------050303040302010403000307 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit That would definitely be an elegant solution. It would still see a current draw of maybe 10 to 20 amps for the fuel pumps, ignition coils and EC-2, but that would be nowhere near the 100 or 100's of amps the starter pulls which is what brings the starter battery to its knees.

A thought -- there's no real reason to run both pumps during start-up, is there?

Finn

Bulent Aliev wrote:
David, I'm thinking more like a small 12V battery only for the avionics bus
protected by an isolator? So the starter won't pull it down, but the battery
will supply initial 12v to the computer. My starter even scrambles the EM2
display if it's on. I'm not so good with electricity, but many of you here
are .
Buly

On 1/18/05 12:26 AM, "David Carter" <dcarter@datarecall.net> wrote:

  
Having lurked on the Aeroelectric List for years, 'Lectric Bob & his Z
diagrams use a "Low Voltage" module (LVM) of some sort that turn on a "low
valtage light" when alternator fails and voltage drops below "min voltage to
charge a battery", something like 13.8v, with voltage regulator set for
something just over 14 v so battery gets charged for sure.

So, given that "data point", looks like it might be useful for us folks with
"computer dependent" engines, which need 9v (for this particular ECU), to
fabricate a second LVM (set for 9.1 or 9.3 v) that turns on a light - or
voice warning - to tell us "voltage too low to start" (i.e., below ECU
minimum voltage required to start).  I'd probably put the light close to
the starter switch.

David
----- Original Message -----
From: "Bulent Aliev" <atlasyts@bellsouth.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Monday, January 17, 2005 10:24 PM
Subject: [FlyRotary] New discovery...


    
For some time I was so proud my engine would start right away. The last
      
time
    
on Friday night I started it few times and everything was fine. Came back
this morning and tried to start it again, no joy? For hours I tried
everything, plugs, coils injectors, everything was fine. Kept cranking,
fired once for a second and died again. Even starting spray didn't do it.
The last thing (lunch time) I measured the voltage while cranking and it
      
was
    
9V. Ahaaa! I remembered something about the computer not working below 9V.
I hooked the charger and went for a long lunch with the airport bums..Came
back in 3 hrs and BINGO! started right away many times.
So the moral of the story is (I think?). If you have enough power to crank
the engine, does not mean that it will start. The starter pulls down all
      
the
    
available juice and the computer takes a break. Any comments?
Buly
      
    



  
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 Archive:   http://lancaironline.net/lists/flyrotary/List.html
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