X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao102.cox.net ([68.230.241.44] verified) by logan.com (CommuniGate Pro SMTP 5.3.1) with ESMTP id 4084447 for flyrotary@lancaironline.net; Fri, 15 Jan 2010 19:32:47 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.44; envelope-from=alventures@cox.net Received: from fed1rmimpo03.cox.net ([70.169.32.75]) by fed1rmmtao102.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20100116003212.ZBFY8308.fed1rmmtao102.cox.net@fed1rmimpo03.cox.net> for ; Fri, 15 Jan 2010 19:32:12 -0500 Received: from BigAl ([72.192.128.205]) by fed1rmimpo03.cox.net with bizsmtp id W0YC1d00L4S1t5C040YC0W; Fri, 15 Jan 2010 19:32:12 -0500 X-VR-Score: 0.00 X-Authority-Analysis: v=1.1 cv=tFsbg6ins7CCNpnljIJNduQMDmn6okYQ4EWCOqLKcEg= c=1 sm=1 a=Vegc0WxVmH5BHtpNDyThtA==:17 a=Ia-xEzejAAAA:8 a=SMQhseXIEhqaXfbe6DwA:9 a=y_cWTFIfQlRAFYKpxqQA:7 a=wKnS6YGFOdLDCojKDxmtI5hLjXQA:4 a=EzXvWhQp4_cA:10 a=2l3w9ks7drAKnfioiPAA:9 a=XJyRgsFACS8bjCrmucgA:7 a=Q-UFUcSeaBRduqLDhKa1nC13DF0A:4 a=Vegc0WxVmH5BHtpNDyThtA==:117 X-CM-Score: 0.00 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Alternator Filter Date: Fri, 15 Jan 2010 16:33:43 -0800 Message-ID: <9D4BC447BC6F43FC967C616DFEE9C702@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0025_01CA9600.80BCBE60" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6856 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Importance: Normal Thread-Index: AcqWODXklAXFHpn6Q3mRplfRq46HogACCeKg In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0025_01CA9600.80BCBE60 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Joe; Gees, that's a weird one. I assume from your note that problem is no ignition trigger pulse, and = that the injectors are firing. Have you determined where the signal is being interrupted? Is the loss of signal from the CAS, or out of the EC2? = The capacitor grounded to the engine will be inducing some sort of opposite signal to ground - maybe affecting the CAS? Just some WAG. =20 I have no filter on the alternator output - never saw more than the = normal ripple there. Could a failed diode in the output converter be making big spikes? Wait - even with alt off, no start? What's in the 'alt filter' besides a capacitor? Is the filter in the circuit when you run the = external wire? =20 Just a few random thoughts - I expect you know more than I about how = this stuff works. =20 Al G =20 -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Joe Ewen Sent: Friday, January 15, 2010 3:13 PM To: Rotary motors in aircraft Subject: [FlyRotary] Alternator Filter =20 I have been having problems with my engine installation. Starts, runs = great - turn on the alternator and the engine starts to miss. Put a scope on = R1 ignition trigger lead and sure enough missing trigger pulses. Turn alternator off no more missing pulses. Looked at the alternator output = with the scope and as expected saw some spikes. Bought an aircraft spruce alternator filter. Ran the engine , worked fine until it would not = prime or run any more. That turned out to be a defective store switch. Replaced = the switch and back to normal. Here is the part I do not yet understand. =20 Engine runs fine, added alternator filter and can not even get a pop. = Take the filter off, starts fine. Filter back on (alt off), no joy. Filter = on (alt on), no joy. Filter off, runs fine. I can not imagine how a filter capacitor is interfering with the ignition of the controller. If anyone = has any insight please feel to speak up. =20 I have 2 wiring ducts: 1. quiet - signals such as to the PCM, ignition firing leads, low voltage sensor, analog signals. 2. Noisy side, = battery cables, ignition power, injector power and signal (twisted pair shielded (shield properly grounded.) =20 Alternator connects to battery cable at the starter. If I run an = external wire between the alternator and the battery (outside the airframe, long = wire - engine in back, battery in front (canard)) everything runs fine.) Aesthetically this might not be a good approach, not to mention the aerodynamic impact. =20 This problem has kicked my butt this week working on it in the cool 20F evening air. Any insight is appreciated, especially why a capacitor = (which does not conduct DC) would render the EC2 controller inoperative would = be appreciated. =20 Thanks, Joe =20 ------=_NextPart_000_0025_01CA9600.80BCBE60 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Joe;

Gees, that’s a weird = one.

I assume from your note that = problem is no ignition trigger pulse, and that the injectors are firing.  Have = you determined where the signal is being interrupted?  Is the loss of = signal from the CAS, or out of the EC2?  The capacitor grounded to the = engine will be inducing some sort of opposite signal to ground – maybe = affecting the CAS?  Just some WAG.

 

I have no filter on the = alternator output – never saw more than the normal ripple there. Could a = failed diode in the output converter be making big spikes? Wait – even = with alt off, no start? What’s in the ‘alt filter’ besides a capacitor? Is the filter in the circuit when you run the external = wire?

 

Just a few random thoughts = – I expect you know more than I about how this stuff works.

 

Al G

 

-----Original = Message-----
From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Joe Ewen
Sent: Friday, January 15, = 2010 3:13 PM
To: Rotary motors in = aircraft
Subject: [FlyRotary] = Alternator Filter

 

I have been having problems = with my engine installation.  Starts, runs great - turn on the alternator = and the engine starts to miss.  Put a scope on R1 ignition trigger lead and = sure enough missing trigger pulses.   Turn alternator off no more = missing pulses.  Looked at the alternator output with the scope and as = expected saw some spikes.  Bought an aircraft spruce alternator = filter.  Ran the engine , worked fine until it would not prime or run any more.  = That turned out to be a defective store switch.  Replaced the switch and = back to normal.  Here is the part I do not yet = understand.

 

Engine runs fine, added = alternator filter and can not even get a pop.  Take the filter off, starts = fine.  Filter back on (alt off), no joy.  Filter on (alt on), no = joy. Filter off, runs fine.  I can not imagine how a filter capacitor is = interfering with the ignition of the controller.  If anyone has any insight = please feel to speak up.

 

I have 2 wiring ducts: 1. = quiet - signals such as to the PCM, ignition firing leads, low voltage sensor, = analog signals.  2. Noisy side, battery cables, ignition power, injector = power and signal (twisted pair shielded (shield properly = grounded.)

 

Alternator connects to = battery cable at the starter.  If I run an external wire between the alternator = and the battery (outside the airframe, long wire - engine in back, battery in = front (canard)) everything runs fine.) Aesthetically this might not be a = good approach, not to mention the aerodynamic impact.

 

This problem has kicked my = butt this week working on it in the cool 20F evening air.  Any insight is appreciated, especially why a capacitor (which does not conduct DC) = would render the EC2 controller inoperative would be = appreciated.

 

Thanks,

Joe

 

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