X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail12.syd.optusnet.com.au ([211.29.132.193] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTPS id 2392485 for flyrotary@lancaironline.net; Wed, 17 Oct 2007 18:29:49 -0400 Received-SPF: none receiver=logan.com; client-ip=211.29.132.193; envelope-from=lendich@optusnet.com.au Received: from george (d220-236-230-45.dsl.nsw.optusnet.com.au [220.236.230.45]) by mail12.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id l9HMT3mI024693 for ; Thu, 18 Oct 2007 08:29:04 +1000 Message-ID: <004001c8110d$2034fe10$2de6ecdc@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: EC2 20B Injector Power Circuits Date: Thu, 18 Oct 2007 08:29:03 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003D_01C81160.F0E6CF90" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Antivirus: avast! (VPS 0657-0, 12/12/2006), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_003D_01C81160.F0E6CF90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 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. =20 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 =20 On 10/17/07, bmears9413@aol.com wrote:=20 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=20 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.=20 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.=20 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.=20 Joe ----- Original Message -----=20 From: bob.kaufmann=20 To: Rotary motors in aircraft=20 Sent: Sunday, October 14, 2007 10:16 PM Subject: [FlyRotary] Re: EC2 20B Injector Power Circuits =20 Al=20 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=20 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.=20 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=20 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. =20 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. =20 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. =20 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.=20 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?=20 Thanks, Joe -------------------------------------------------------------------------= --- Email and AIM finally together. You've gotta check out free AOL = Mail! =20 -------------------------------------------------------------------------= ----- 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.=20 Version: 7.5.488 / Virus Database: 269.14.13/1074 - Release Date: = 16/10/2007 2:14 PM ------=_NextPart_000_003D_01C81160.F0E6CF90 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 Bob,
Have you had the engine running with = those exhausts=20 - do they cut the noise down any. I certainly like the look of the = exhausts=20 especially for that type of plane, but wonder if you discovered any = advantage in multiple outlets.
George (down under)
I'm=20 thinking I purchased after the snubber update. Is there a certain date = of=20 manufacturer that insures me of this? I dont remember the date on the = box, its=20 at home and I'm screwing around on the computer at work instead of = working=20 ;)...I do know that my unit already has the right choke = installed.

Bob=20 Mears
Supermarine Spitfire


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

Bob,  I don't know when you last updated your EC2 but if you = have=20 the snubber update already, there is no need to update again due to = the diode=20 and staging relay changes being discussed here.  These changes = are to=20 parts external to the EC2.  If it is not clear to you where to = add the=20 diodes and relay by looking at the schematic I posted, feel free to = ask for=20 specifics.   I want your project to succeed almost as much = as you=20 do. 
 
If you don't have the snubber update, I would highly recommend = that you=20 get it prior to any engine testing or tuning.
 
Tracy Crook

 
On 10/17/07, bmears9413@aol.com <bmears9413@aol.com> = wrote:=20
So=20 does this mean I shouldnt finish installing my EC2 cause I may have = to send=20 it back to Tracy? Nows the time for me. I'm installing now. =

Bob=20 Mears
Supermarine Spitfire


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

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

 
Al =
 
Hate to = continue to=20 display my ignorance but what is a Schottky diodes.  When it = comes to=20 electronics I'm as dumb as a stump.
 
Bob = K
 
From: Rotary motors in aircraft [=20 mailto:flyrotary@lancaironline.net] On Behalf Of Al=20 Gietzen
Sent: Sunday, October 14, 2007 5:42 = PM
To:=20 Rotary motors in aircraft
Subject: [FlyRotary] Re: EC2 = 20B=20 Injector Power Circuits
 
Joe;
 
You are = right.  We=20 discovered this crossfeed issue some time back.  Is applies = only to=20 the 20B version as the 13B has separate drivers for each set.=20  Install Schottky diodes in the circuits for each = injector. =20 Tracy is aware of this, and has installed the diodes in his as = well.=20
 
Al
 
-----Original = Message-----
From: Rotary=20 motors in aircraft [=20 mailto:flyrotary@lancaironline.net] On Behalf Of Joe=20 Ewen
Sent: Sunday, October 14, 2007 3:20 = PM
To: Rotary=20 motors in aircraft
Subject: [FlyRotary] EC2 20B Injector = Power=20 Circuits
 
I have been=20 testing my wiring harness from the EC2.  I found a behavior = that I=20 did not expect.  The manual drawing (EC2 manual) show a = single=20 injector supply that splits at the Injector primary and secondary = disable=20 switches.  On my installation, I have 2 separate feeder = circuits,=20 supply Primary comes from battery 1, and supply Secondary = comes from=20 battery 2.  I did this for redundancy.  If I had a = failure such=20 as a short to ground in either circuit, its related overload = should trip,=20 but the other circuit should remain active.  =
 
While=20 testing the injector circuits, I noticed what I would term an=20 abnormality.  With both injector disable switches in the = enable=20 position, I turned on the power for the primary circuit (I have = LED=20 indicators on all circuits that annunciate power present) and the=20 secondary circuit also showed power present even though the power = switch=20 for the secondary circuit was off.  The same is true when the = secondary circuit is engaged and the primary is off. =20
 
Initially=20 this led me to think I had miss wired something in the = circuit. =20 After checking out the wiring, I found no issues.  So I took = a closer=20 look at the wiring diagram in the manual.  It turns out the = power was=20 being back feed through the injectors to the opposite = circuit.  On=20 the 20B version of the EC2, the injector control lines for each = rotors=20 injectors are junctioned going into the EC2.  For example the = Rotor 1=20 Primary and Secondary control lines are junctioned into a single = input=20 point at the EC2. 
 
I can see=20 several situations where this may lead to undesirable = operation.  For=20 example, if the Primary circuit had a hard short to ground, it = would take=20 out the primary circuit's overload (CB or Fuse.)  Since the = primary=20 and secondary circuits are electrically connected on the control = line, the=20 other circuit would also trip.  Another situation that could = occur is=20 a medium to high resistance short.  Current would then flow=20 uncontrolled through the unaffected circuit's injector to the = affected=20 circuit's injector then to the resistance short.  This could = keep=20 both injectors on 100%.  While this situation is unlikely,=20 it seems possible.
 
I=20 believe the 13B version uses separate control lines for each=20 injector, so this in not likely to be an issue on the 13B=20 version.
 
It appears=20 that isolation diodes are needed to prevent these possible = problems. =20 Before making any changes I have to look the circuit over more = closely, as=20 well as a call to Tracy on the next service day.  My question = to the=20 group, especially anyone with a 20B, is am I looking at this = wrong?=20
 
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:=20 16/10/2007 2:14 PM
------=_NextPart_000_003D_01C81160.F0E6CF90--