X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 30 [X] Return-Path: Received: from fed1rmmtao102.cox.net ([68.230.241.44] verified) by logan.com (CommuniGate Pro SMTP 5.1.8) with ESMTP id 1990863 for flyrotary@lancaironline.net; Tue, 17 Apr 2007 23:44:33 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.44; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao103.cox.net (InterMail vM.7.05.02.00 201-2174-114-20060621) with ESMTP id <20070415155511.DWXY1226.fed1rmmtao103.cox.net@fed1rmimpo02.cox.net> for ; Sun, 15 Apr 2007 11:55:11 -0400 Received: from BigAl ([72.192.132.90]) by fed1rmimpo02.cox.net with bizsmtp id nTvA1W0061xAn3c0000000; Sun, 15 Apr 2007 11:55:10 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: Power source isolation Date: Sun, 15 Apr 2007 08:55:52 -0800 Message-ID: <000001c77f7e$ed6ba490$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C77F3B.DF486490" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C77F3B.DF486490 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable I would not have expected the EC2 controller to put noise into the = supply line, but then again I have not put a scope on a running unit yet. What level spikes have you observed? And should I consider a capacitor to absorb/dissipate potential spikes? I used Schottky diodes on the supply lines ( due to the low forward voltage drop characteristics.) =20 Joe =20 Joe; =20 We are still trying to resolve the settings corruption issue, and have = added a number of additional filters on the board, the effectiveness of which = is yet to be proven. Regarding the isolation diodes, I also have Schottky diodes between the batteries and the 'hot' bus that feeds the injector = and the coil power to prevent a failure in one battery circuit from = affecting the other. It may be that noise propagated in these circuits being = isolated from the battery is a more likely an issue than isolation of the power = feeds to the EC2. =20 The reality is that after putting filters at the coils to kill spikes = coming back from there, we do not see any noise levels on any pins expected to = be of concern. But since the problem still existed we assume that there = are some spikes at times we didn't observe; and in studying the circuits, = and what is different in my setup than others; we are speculating that the isolation diodes could exacerbate the issue. More will be known in a = couple of weeks I as get some other changes/fixes completed, and get back in = the air. After a few low-power engine runs since the addition of the = filters, there has been no changes of settings noted so far. =20 Al ------=_NextPart_000_0001_01C77F3B.DF486490 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

I would not have expected = the EC2 controller to put noise into the supply line, but then again I have not = put a scope on a running unit yet.  What level spikes have you observed? = And should I consider a capacitor to absorb/dissipate potential = spikes?  I used Schottky diodes on the supply lines ( due to the low forward = voltage drop characteristics.)

 

Joe

 

Joe;

 

We are still trying to resolve = the settings corruption issue, and have added a number of additional filters on the = board, the effectiveness of which is yet to be proven.  Regarding the = isolation diodes, I also have Schottky diodes between the batteries and the = ‘hot’ bus that feeds the injector and the coil power to prevent a failure in = one battery circuit from affecting the other.  It may be that noise = propagated in these circuits being isolated from the battery is a more likely an = issue than isolation of the power feeds to the EC2.

 

The reality is that after putting filters at the coils to kill spikes coming back from there, we do not = see any noise levels on any pins expected to be of concern.  But since the = problem still existed we assume that there are some spikes at times we = didn’t observe; and in studying the circuits, and what is different in my setup than = others; we are speculating that the isolation diodes could exacerbate the = issue.  More will be known in a couple of weeks I as get some other changes/fixes = completed, and get back in the air.  After a few low-power engine runs since = the addition of the filters, there has been no changes of settings noted so = far.

 

Al

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