Received-SPF: pass
 receiver=logan.com; client-ip=72.52.218.78; envelope-from=bob@bob-white.com
Date: Mon, 6 Jul 2009 06:42:54 -0600
From: Bob White <bob@bob-white.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Below staging
Message-Id: <20090706064254.6238c045.bob@bob-white.com>
In-Reply-To: <list-3746138@logan.com>
References: <list-3746138@logan.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

Thanks Steve,

There is clearly something I'm missing then.  It occurred to me last
night after turning off the computer that pushing the EC2 into staging
when cold start was activated would cut the pulse width in half and
activate the secondaries.  Then the cold start function would double
the pulse width bringing it back to the original value.  This is the
same result as I was postulating.  But if the staging bit is not set
with the secondaries turned off, it doesn't seem quite right and I
don't know how the EC2 knows the difference.  I may have to put my scope
on it as soon as I get the engine running again.  Even though I'm
putting the engine in a car, It's still set up with the EC2 and EM2
just like it was in the plane.  I just want to find out how well it
will work in that application.

Bob W.


On Mon, 6 Jul 2009 00:24:28 -0600
Steven Boese <sboese@uwyo.edu> wrote:

> 
> Bob,
> 
> In contrast to when the primary injector power is off, when the
> secondary injectors are turned off and the cold switch on, the EC2
> indicates staging is taking place normally at the staging threshold, in
> my case at about 20 inches MAP.  The engine doesn't go lean after
> staging is indicated, however. When idling with the secondary injectors
> turned off and the cold switch on, the EC2 indicates no staging has
> taken place.  Of course, what the EC2's staging data bit is telling the
> outside world and what The EC2 is actually doing may be two different
> things.  
> 
> Steve Boese
>   
> 
> 
> 
> -----Original Message-----
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
> Behalf Of Bob White
> Sent: Sunday, July 05, 2009 9:12 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: Below staging
> 
> Hi Steve,
> 
> No offense, but I'm quite sure the EC2 doesn't know if the injectors
> are powered or not.  The disable switches operate on the power leads to
> the injectors and the EC2 pulls the other side of the injector to
> ground to fire it.  There's no input to tell the EC2 whether power is
> applied or not.  What it does know is that the cold start switch is
> activated.  In Tracy's wiring scheme, that happens automatically when a
> disable switch is activated.  You have to do it manually but it amount
> to the same effect. Your description is exactly the way it is supposed
> to work.
> 
> You might also note that with the engine warmed up and idling with the
> cold start switch off, you can turn off the secondary injectors and the
> engine will run fine whether the cold start switch is on or off.  The
> fact that it runs fine with the secondaries off and the cold switch on
> emphasizes that the cold start function doesn't double the pulse width
> below the staging point.  That would deliver too much gas to the engine.
> 
> You mentioned that the staged indicator was on with the primaries off
> and the cold switch on.  Did you notice if the staged indicator was on
> with the secondaries off and the cold switch on?  I would expect that
> it was.  I think that's an indication that both banks of injectors are
> active even though below the staging point.  Only those injectors that
> are powered through the disable switches will operate.
> 
> I agree, it's not absolutely necessary to understand exactly how the
> various boxes work to use them.  I'm an electronics guy though and it's
> of interest to me.  I didn't even think about the below staging issue
> until Mark Supinski asked a question on the AeroElectric list about a
> problem he was having using a single three way switch for the injector
> disable function.  Turns out he wasn't activating the cold start either
> and the engine would always die if he disabled the primaries.  That's
> when it struck me that when cold start is active, both banks of
> injectors have to be operating from the EC2 side to make injector
> disable work even when below staging.
> 
> Ed Anderson isn't quite convinced I have it right either.  If I can't
> convince him, I'll have to change my story.  Or, Tracy will come
> back from vacation and straighten me out.  :)
> 
> Bob W.
> 
> 
> 
> 
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html


-- 
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/