X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTP id 5565805 for flyrotary@lancaironline.net; Tue, 29 May 2012 11:18:53 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=2.0 cv=ReYS+iRv c=1 sm=0 a=g3L/TDsr+eNLfIieSKfGkw==:17 a=AHkS0RJitIMA:10 a=UtmUoTa5nP0A:10 a=05ChyHeVI94A:10 a=ayC55rCoAAAA:8 a=oCcaPWc0AAAA:8 a=nMUa0s2wI5fvAkOnQTgA:9 a=wPNLvfGTeEIA:10 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=RZWN2EUo_khDlw_9-7cA:9 a=_W_S_7VecoQA:10 a=tXsnliwV7b4A:10 a=MSl-tDqOz04A:10 a=EzXvWhQp4_cA:10 a=g3L/TDsr+eNLfIieSKfGkw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.170.10 Received: from [174.110.170.10] ([174.110.170.10:54141] helo=EdPC) by cdptpa-oedge01.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 15/AC-07741-9B8E4CF4; Tue, 29 May 2012 15:18:17 +0000 Message-ID: From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: injector imbalance Date: Tue, 29 May 2012 11:18:06 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0033_01CD3D8C.B8D958E0" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_0033_01CD3D8C.B8D958E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Mark, it does not take much resistance to protect the injector from = current draws by other devices. I install a 200 ohm resistor between my = EFISM and the driving injector. That way at a nominal 12 volts - the = most current the other device would draw (if shorted to ground) is I = =3D E/R =3D 12/200 =3D 60 ma (probably much less is the device is = probably not a direct ground) not enough to pull your injector open.=20 I put it in there (as close to the injector as I could) so that if by = chance my EFISM lead from the injector got shorted to ground it would = not pull the injector open. The resistance is not critical, I have used from 100-500 ohms. You = could increase the resistance until your other device stopped working = (and then reduce the resistance a bit from there). The quickest was to see if that is the problem is simply to disconnect = that aux lead to injector. Ed From: Mark Steitle=20 Sent: Tuesday, May 29, 2012 11:02 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: injector imbalance Steve,=20 I almost understand what you're telling me. Bill Shultz commented on = the Blue Mountain EFIS using the #1 injector for RPM. So, if the BMA = EFIS is connected to the #1 injector lead, then it could be causing the = over rich condition on that rotor. I'm not sure if I did that or not = as my BMA RPM indicator has never worked. It has been many years since = I installed the EFIS, so I don't recall if this was done or not. But = this will be the next thing I will check. =20 Thanks, Mark=20 On Tue, May 29, 2012 at 9:47 AM, Steven W. Boese = wrote: Mark, If a device is connected to the EC2 side of the primary injector of = rotor 1 and this device has diode protection from the inductive spike = produced by the injector winding, then this injector will deliver more = fuel than the injector pulse width would indicate. The appearance on = the O-scope would more evident in the lack of an inductive spike for = this injector rather than in a difference in the signal pulse width.=20 Steve Boese RV6A, 1986 13B NA, RD1A, EC2 No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2178 / Virus Database: 2425/5030 - Release Date: = 05/29/12 ------=_NextPart_000_0033_01CD3D8C.B8D958E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Mark, it does not take much resistance to = protect the=20 injector from current draws by other devices.  I install a 200 ohm = resistor=20 between my EFISM and the driving injector.  That way at a nominal = 12 volts=20 - the most current the other device would  draw (if shorted to = ground)=20 is I =3D E/R =3D 12/200 =3D 60 ma (probably much less is the device is = probably not a=20 direct ground) not enough to pull your injector = open. 
 
 I put it in there (as close to the = injector as I=20 could) so that if by chance my EFISM lead from the injector got shorted = to=20 ground it would not pull the injector open.
 
The resistance is not critical, I have used from = 100-500=20 ohms.  You could increase the resistance until your other device = stopped=20 working (and then reduce the resistance a bit from there).
 
The quickest was to see if that is the problem = is simply=20 to disconnect that aux lead to injector.
 
Ed

Sent: Tuesday, May 29, 2012 11:02 AM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: injector = imbalance

Steve,=20

I almost understand what you're telling me.  Bill Shultz = commented on=20 the Blue Mountain EFIS using the #1 injector for RPM.  So, if the = BMA EFIS=20 is connected to the #1 injector lead, then it could be causing the over = rich=20 condition on that rotor.   I'm not sure if I did that or not as my = BMA RPM=20 indicator has never worked.  It has been many years since I = installed the=20 EFIS, so I don't recall if this was done or not.  But this will be = the next=20 thing I will check.  

Thanks,
Mark 

On Tue, May 29, 2012 at 9:47 AM, Steven W. = Boese <SBoese@uwyo.edu> wrote:

Mark,

 

If a device is connected to the EC2 side of the primary injector of = rotor 1=20 and this device has diode protection from the inductive spike produced = by the=20 injector winding, then this injector will deliver more fuel than the = injector=20 pulse width would indicate.  The appearance on the O-scope would = more=20 evident in the lack of an inductive spike for this injector rather = than in a=20 difference in the signal pulse width. 

 

Steve Boese
RV6A, 1986 13B NA, RD1A,=20 = EC2

No virus found in this=20 message.
Checked by AVG - www.avg.com
Version: 2012.0.2178 / = Virus=20 Database: 2425/5030 - Release Date: 05/29/12

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