X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imo-m27.mx.aol.com ([64.12.137.8] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2392486 for flyrotary@lancaironline.net; Wed, 17 Oct 2007 18:34:56 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.8; envelope-from=BMears9413@aol.com Received: from BMears9413@aol.com by imo-m27.mx.aol.com (mail_out_v38_r9.3.) id q.c2c.1e65f845 (37038) for ; Wed, 17 Oct 2007 18:34:11 -0400 (EDT) Received: from webmail-mf02 (webmail-mf02.webmail.aol.com [64.12.88.215]) by cia-db02.mx.aol.com (v119.12) with ESMTP id MAILCIADB028-90ae47168de31b9; Wed, 17 Oct 2007 18:34:11 -0400 References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] Re: EC2 20B Injector Power Circuits Date: Wed, 17 Oct 2007 18:34:11 -0400 In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: bmears9413@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8C9DF24F937B5BE_A00_4484_webmail-mf02.sysops.aol.com" X-Mailer: AOL WebMail 31361-STANDARD Received: from 65.182.71.8 by webmail-mf02.sysops.aol.com (64.12.88.215) with HTTP (WebMailUI); Wed, 17 Oct 2007 18:34:11 -0400 Message-Id: <8C9DF24F937B5BE-A00-21CC@webmail-mf02.sysops.aol.com> X-AOL-IP: 64.12.88.215 X-Spam-Flag: NO ----------MB_8C9DF24F937B5BE_A00_4484_webmail-mf02.sysops.aol.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii" George, Havent started it yet. Hope to by the end of the year. Each fo the 2" outlets actuall have a 1" exhaust port in each of them. I'm hoping for some muffler action by doing that. I cant wait to hear it, but I wont fire it untill I think everything is ready. Bob Mears Supermarine Spitfire -----Original Message----- From: George Lendich To: Rotary motors in aircraft Sent: Wed, 17 Oct 2007 5:29 pm Subject: [FlyRotary] Re: EC2 20B Injector Power Circuits ?Bob, Have you had the engine running with those exhausts - do they cut the noise down any. I certainly like the look of the exhausts especially for that type of plane, but wonder if?you discovered any advantage in multiple outlets. George (down under) I'm thinking I purchased after the snubber update. Is there a certain date of manufacturer that insures me of this? I dont remember the date on the box, its at home and I'm screwing around on the computer at work instead of working ;)...I do know that my unit already has the right choke installed. Bob Mears Supermarine Spitfire -----Original Message----- From: Tracy Crook To: Rotary motors in aircraft Sent: Wed, 17 Oct 2007 9:33 am Subject: [FlyRotary] Re: EC2 20B Injector Power Circuits Bob,? I don't know when you last updated your EC2 but if you have the snubber update already, there is no need to update again due to the diode and staging relay changes being discussed here.? These changes are to parts external to the EC2.? If it is not clear to you where to add the diodes and relay by looking at the schematic I posted, feel free to ask for specifics.?? I want your project to succeed almost as much as you do.? ? If you don't have the snubber update, I would highly recommend that you get it prior to any engine testing or tuning. ? Tracy Crook ? On 10/17/07, bmears9413@aol.com wrote: So does this mean I shouldnt finish installing my EC2 cause I may have to send it back to Tracy? Nows the time for me. I'm installing now. Bob Mears Supermarine Spitfire -----Original Message----- From: Joe Ewen To: Rotary motors in aircraft Sent: Sun, 14 Oct 2007 10:28 pm Subject: [FlyRotary] Re: EC2 20B Injector Power Circuits Hi Bob, Don't know if you don't ask.? A diode is a device that allows current to flow only in one direction (DC circuit.)? Schottky is a particular diode construction.? One desirable feature of a Schottky is that it has a low forward voltage drop.? All diodes have a drop in voltage (like a small resistor.)? In this case, the lower voltage drop allows the injectors to continue firing slightly longer than other diode types in the event of an alternator failure and lowering battery voltage. ? On the 20B, the injector control lines are wired together, installing the diodes prevents the current / voltage from back feeding between the primary and secondary circuits and the possible failure modes I noted earlier.? Application of diode(s) in this manner is typically referred to as isolation diodes. ? Since the EC2 controller internal jumps the 2 controller power feeds, I installed isolation diodes (Schottky) to prevent similar problems between the 2 supply circuits. ? You may also find diodes useful in making?annunciator press to test circuits.? If you have 2 devices?such as a transponder and a GPS that both need to share altitude encoder inputs, isolation diodes would be used.? Of course with any avionics installations, follow the manufactures guidelines. ? Joe ----- Original Message ----- From: bob.kaufmann To: Rotary motors in aircraft Sent: Sunday, October 14, 2007 10:16 PM Subject: [FlyRotary] Re: EC2 20B Injector Power Circuits ? Al ? Hate to continue to display my ignorance but what is a Schottky diodes.? When it comes to electronics I'm as dumb as a stump. ? Bob K ? From: Rotary motors in aircraft [ mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen Sent: Sunday, October 14, 2007 5:42 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: EC2 20B Injector Power Circuits ? Joe; ? You are right.? We discovered this crossfeed issue some time back. ?Is applies only to the 20B version as the 13B has separate drivers for each set. ?Install Schottky diodes in the circuits for each injector.? Tracy is aware of this, and has installed the diodes in his as well. ? Al ? -----Original Message----- From: Rotary motors in aircraft [ mailto:flyrotary@lancaironline.net] On Behalf Of Joe Ewen Sent: Sunday, October 14, 2007 3:20 PM To: Rotary motors in aircraft Subject: [FlyRotary] EC2 20B Injector Power Circuits ? I have been testing my wiring harness from the EC2.? I found a behavior that I did not expect.? The manual drawing (EC2 manual) show a single injector supply that splits at the Injector primary and secondary disable switches.? On my installation, I have 2 separate feeder circuits, supply Primary comes from battery 1, and?supply Secondary comes from battery 2.? I did this for redundancy.? If I had a failure such as a short to ground in either circuit, its related overload should trip, but the other circuit should remain active.? ? While testing the injector circuits, I noticed what I would term an abnormality.? With both injector disable switches in the enable position, I turned on the power for the primary circuit (I have LED indicators on all circuits that annunciate power present) and the secondary circuit also showed power present even though the power switch for the secondary circuit was off.? The same is true when the secondary circuit is engaged and the primary is off.? ? Initially this led me to think I had miss wired something in the circuit.? After checking out the wiring, I found no issues.? So I took a closer look at the wiring diagram in the manual.? It turns out the power was being back feed through the injectors to the opposite circuit.? On the 20B version of the EC2, the injector control lines for each rotors injectors are junctioned going into the EC2.? For example the Rotor 1 Primary and Secondary control lines are junctioned into a single input point at the EC2.? ? I can see several situations where this may lead to undesirable operation.? For example, if the Primary circuit had a hard short to ground, it would take out the primary circuit's overload (CB or Fuse.)? Since the primary and secondary circuits are electrically connected on the control line, the other circuit would also trip.? Another situation that could occur is a medium to high resistance short.? Current would then flow uncontrolled through the unaffected circuit's injector to the affected circuit's injector then to the resistance short.? This could keep both injectors on 100%.? While this situation is unlikely, it?seems possible. ? I believe?the 13B version uses separate control lines for each injector, so this in not likely to be an issue on the 13B version. ? It appears that isolation diodes are needed to prevent these possible problems.? Before making any changes I have to look the circuit over more closely, as well as a call to Tracy on the next service day.? My question to the group, especially anyone with a 20B, is am I looking at this wrong? ? Thanks, Joe Email and AIM finally together. You've gotta check out free AOL Mail! ? Email and AIM finally together. You've gotta check out free AOL Mail! No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.14.13/1074 - Release Date: 16/10/2007 2:14 PM ________________________________________________________________________ Email and AIM finally together. You've gotta check out free AOL Mail! - http://mail.aol.com ----------MB_8C9DF24F937B5BE_A00_4484_webmail-mf02.sysops.aol.com Content-Transfer-Encoding: 7bit Content-Type: text/html; charset="us-ascii" George,
Havent started it yet. Hope to by the end of the year. Each fo the 2" outlets actuall have a 1" exhaust port in each of them. I'm hoping for some muffler action by doing that. I cant wait to hear it, but I wont fire it untill I think everything is ready.

Bob Mears
Supermarine Spitfire


-----Original Message-----
From: George Lendich <lendich@optusnet.com.au>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Wed, 17 Oct 2007 5:29 pm
Subject: [FlyRotary] Re: EC2 20B Injector Power Circuits

 Bob,
Have you had the engine running with those exhausts - do they cut the noise down any. I certainly like the look of the exhausts especially for that type of plane, but wonder if you discovered any advantage in multiple outlets.
George (down under)
I'm thinking I purchased after the snubber update. Is there a certain date of manufacturer that insures me of this? I dont remember the date on the box, its at home and I'm screwing around on the computer at work instead of working ;)...I do know that my unit already has the right choke installed.

Bob Mears
Supermarine Spitfire


-----Original Message-----
From: Tracy Crook <tracy@rotaryaviation.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Wed, 17 Oct 2007 9:33 am
Subject: [FlyRotary] Re: EC2 20B Injector Power Circuits

Bob,  I don't know when you last updated your EC2 but if you have the snubber update already, there is no need to update again due to the diode and staging relay changes being discussed here.  These changes are to parts external to the EC2.  If it is not clear to you where to add the diodes and relay by looking at the schematic I posted, feel free to ask for specifics.   I want your project to succeed almost as much as you do. 
 
If you don't have the snubber update, I would highly recommend that you get it prior to any engine testing or tuning.
 
Tracy Crook

 
On 10/17/07, bmears9413@aol.com <bmears9413@aol.com> wrote:
So does this mean I shouldnt finish installing my EC2 cause I may have to send it back to Tracy? Nows the time for me. I'm installing now.

Bob Mears
Supermarine Spitfire


-----Original Message-----
From: Joe Ewen <Jewen@comporium.net >
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sun, 14 Oct 2007 10:28 pm
Subject: [FlyRotary] Re: EC2 20B Injector Power Circuits

Hi Bob,
Don't know if you don't ask.  A diode is a device that allows current to flow only in one direction (DC circuit.)  Schottky is a particular diode construction.  One desirable feature of a Schottky is that it has a low forward voltage drop.  All diodes have a drop in voltage (like a small resistor.)  In this case, the lower voltage drop allows the injectors to continue firing slightly longer than other diode types in the event of an alternator failure and lowering battery voltage.
 
On the 20B, the injector control lines are wired together, installing the diodes prevents the current / voltage from back feeding between the primary and secondary circuits and the possible failure modes I noted earlier.  Application of diode(s) in this manner is typically referred to as isolation diodes.
 
Since the EC2 controller internal jumps the 2 controller power feeds, I installed isolation diodes (Schottky) to prevent similar problems between the 2 supply circuits.
 
You may also find diodes useful in making annunciator press to test circuits.  If you have 2 devices such as a transponder and a GPS that both need to share altitude encoder inputs, isolation diodes would be used.  Of course with any avionics installations, follow the manufactures guidelines.
 
Joe
----- Original Message -----
Sent: Sunday, October 14, 2007 10:16 PM
Subject: [FlyRotary] Re: EC2 20B Injector Power Circuits

 
Al
 
Hate to continue to display my ignorance but what is a Schottky diodes.  When it comes to electronics I'm as dumb as a stump.
 
Bob K
 
From: Rotary motors in aircraft [ mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen
Sent: Sunday, October 14, 2007 5:42 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: EC2 20B Injector Power Circuits
 
Joe;
 
You are right.  We discovered this crossfeed issue some time back.  Is applies only to the 20B version as the 13B has separate drivers for each set.  Install Schottky diodes in the circuits for each injector.  Tracy is aware of this, and has installed the diodes in his as well.
 
Al
 
-----Original Message-----
From: Rotary motors in aircraft [ mailto:flyrotary@lancaironline.net] On Behalf Of Joe Ewen
Sent: Sunday, October 14, 2007 3:20 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] EC2 20B Injector Power Circuits
 
I have been testing my wiring harness from the EC2.  I found a behavior that I did not expect.  The manual drawing (EC2 manual) show a single injector supply that splits at the Injector primary and secondary disable switches.  On my installation, I have 2 separate feeder circuits, supply Primary comes from battery 1, and supply Secondary comes from battery 2.  I did this for redundancy.  If I had a failure such as a short to ground in either circuit, its related overload should trip, but the other circuit should remain active. 
 
While testing the injector circuits, I noticed what I would term an abnormality.  With both injector disable switches in the enable position, I turned on the power for the primary circuit (I have LED indicators on all circuits that annunciate power present) and the secondary circuit also showed power present even though the power switch for the secondary circuit was off.  The same is true when the secondary circuit is engaged and the primary is off. 
 
Initially this led me to think I had miss wired something in the circuit.  After checking out the wiring, I found no issues.  So I took a closer look at the wiring diagram in the manual.  It turns out the power was being back feed through the injectors to the opposite circuit.  On the 20B version of the EC2, the injector control lines for each rotors injectors are junctioned going into the EC2.  For example the Rotor 1 Primary and Secondary control lines are junctioned into a single input point at the EC2. 
 
I can see several situations where this may lead to undesirable operation.  For example, if the Primary circuit had a hard short to ground, it would take out the primary circuit's overload (CB or Fuse.)  Since the primary and secondary circuits are electrically connected on the control line, the other circuit would also trip.  Another situation that could occur is a medium to high resistance short.  Current would then flow uncontrolled through the unaffected circuit's injector to the affected circuit's injector then to the resistance short.  This could keep both injectors on 100%.  While this situation is unlikely, it seems possible.
 
I believe the 13B version uses separate control lines for each injector, so this in not likely to be an issue on the 13B version.
 
It appears that isolation diodes are needed to prevent these possible problems.  Before making any changes I have to look the circuit over more closely, as well as a call to Tracy on the next service day.  My question to the group, especially anyone with a 20B, is am I looking at this wrong?
 
Thanks,
Joe
Email and AIM finally together. You've gotta check out free AOL Mail!
 

Email and AIM finally together. You've gotta check out free AOL Mail!
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.488 / Virus Database: 269.14.13/1074 - Release Date: 16/10/2007 2:14 PM
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