X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from host.roblinphoto.com ([72.52.218.78] verified) by logan.com (CommuniGate Pro SMTP 5.2.5) with ESMTPS id 3022428 for flyrotary@lancaironline.net; Sat, 12 Jul 2008 00:17:51 -0400 Received-SPF: pass receiver=logan.com; client-ip=72.52.218.78; envelope-from=bob@bob-white.com Received: from c-68-35-160-229.hsd1.nm.comcast.net ([68.35.160.229]:56168 helo=quail) by host.roblinphoto.com with esmtpa (Exim 4.69) (envelope-from ) id 1KHWXq-0005qv-4A for flyrotary@lancaironline.net; Fri, 11 Jul 2008 22:17:14 -0600 Date: Fri, 11 Jul 2008 22:12:44 -0600 From: Bob White To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] No Spark from Coils Message-Id: <20080711221244.7d53520a.bob@bob-white.com> In-Reply-To: References: X-Mailer: Sylpheed 2.5.0 (GTK+ 2.12.0; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - host.roblinphoto.com X-AntiAbuse: Original Domain - lancaironline.net X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - bob-white.com Hi John, Pin A to engine ground is correct, pin B to EC2 ground is correct, +12V on pin D is correct. I'm not sure what you will read on pin C with a voltmeter. It should pulse from 0 to +12V, and you will need an oscilloscope to see it properly. What really concerns me is the 27 Volts. The EC2 ground lead is connected to the EC2 ground stud, and that should be connected to airframe ground near the EC2, so that voltage should basically be zero. I'm not sure why you would see anything anywhere above the 12 to 14 volt bus voltage. My first suggestion would be to double check ground connections at the EC2, and make sure there is a ground strap between the engine and battery that will handle the starter currents. The minimum load on pins 20 and 21 is several K ohms, and shouldn't cause any problems, but just to be sure, can you disconnect it temporarily? Bob W. On Fri, 11 Jul 2008 23:29:31 -0400 "John Downing" wrote: > Bob W, today I joined the non-start rotor club, I expected it not to start after following the Saga of Buly and Chris. We don't have any ignition. We checked the wires to the coils and , all coil plugs have ground to block on pin A, ground to EC2 on pin B, voltage on Pin D. On cranking, Pin C on the volt ohm meter on cranking shows 9 volts, dropping to 7 volts which is a steady reading on not pulsing. Pin B which is the ground to the EC2, voltage rises to 27 volts. What is the voltage that we should be seeing on pins B and C and should C show a pushing voltage? Is the Tach interface that you sent me, which is connected to EC2 pins 20 and 21 for leading coils having anything to do with the fact that the coils are not firing. JohnD > -- 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/cables/