X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 64 [XX] (100%) BODY: contains text similar to "low payment" Return-Path: Received: from smtprh03.spirittelecom.com ([165.166.0.79] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTPS id 1914856 for flyrotary@lancaironline.net; Sun, 11 Mar 2007 10:54:55 -0400 Received-SPF: pass receiver=logan.com; client-ip=165.166.0.79; envelope-from=jewen@comporium.net X-Report-Abuse-To: abuse@spirittelecom.com X-DKIM: Sendmail DKIM Filter v0.5.2 smtprh03.spirittelecom.com l2BEs5dw001841 DKIM-Signature: a=rsa-sha1; c=relaxed/simple; d=comporium.net; s=spiritmail; t=1173624848; bh=WmwZnMJpLfk4IPnOJf4aIvHtyNs=; h=Message-ID:From:To: References:Subject:Date:MIME-Version:Content-Type:X-Priority: X-MSMail-Priority:X-Mailer:X-MIMEOLE:X-Virus-Scanned: X-Virus-Status; b=dmZkOSSFD8meyiZLqKqnglrZot58MjAdiaJmn/4sZn/FWTuOO 3oD1DCrNlQBhR6UWtU9KMTT7+mAh7L73N4RiQ== Received: from Engineer1 (208-104-87-198.lnhe.2wcm.comporium.net [208.104.87.198] (may be forged)) by smtprh03.spirittelecom.com (8.13.6/8.13.1) with SMTP id l2BEs5dw001841 for ; Sun, 11 Mar 2007 14:54:08 GMT Message-ID: <009f01c763ed$1cf3fee0$6e05a8c0@cooleygroup.local> From: "Joe Ewen" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: The truth??? / Injector flow rate mystery solved Date: Sun, 11 Mar 2007 10:54:04 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_009C_01C763CB.95854AC0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: ClamAV 0.88/2807/Sun Mar 11 09:57:00 2007 on smtprh03.spirittelecom.com X-Virus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_009C_01C763CB.95854AC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageED, George, Steve, A strong contributor to this may lie in the fundamental design of the = EC2. It's output control is sinking rather than sourcing. If it were = sourcing the positive EMF would be switched and the other side of the = could would always be grounded, leaving a place for the coil breakdown = current to go. Well the controller is what it is, so the question = become what can we do to work around the problem? Encoders are used = often in industrial applications, these are generally connected in a = sinking fashion just as the EC2. In high frequency (encoder pulses) = applications the impedance of the input electronics is often to slow to = bleed of the leading edge of the encoder on voltage before the next = pulse cycle. End result is that the input does not detect tithe state = change. The solution is very simple for the described situation is very = simple. Installing a pull down resistor between the sensor signal line = and ground. This technique is used with standard input electronics with = pulse trains up to 50kHz, which translates to a cycle period of 20=B5S. How does this translate to our application? If we were to add a pull = down resistor in injector signal line, which may very well be a simple = method to reducing the off delay time. This would of course add a small = increase in the current for the injector circuits, but that increase = would likely be minimal. The value of the resistor would certainly need = to be determined using factors such as Injector turn on voltage, turn = off voltage, device current, etc. IMO this may be a simple solution to = the delay issue. In the end I defer final recommendations to Tracy, who certainly knows = the characteristics of his controller system better than I. Joe ----- Original Message -----=20 From: Steven Boese=20 To: Rotary motors in aircraft=20 Sent: Saturday, March 10, 2007 11:44 PM Subject: [FlyRotary] Re: The truth??? / Injector flow rate mystery = solved Ed and George, =20 In my plane, at least, injector open times need to be less than 2 ms = at idle and just above the staging point. This is not possible with a = minimum open time of 2 ms due to the delay on closing. You can program = the EC2 for less than 2 ms but the hardware is unable to do this. That = means that the problem can't be fixed with software or programming = different values in the map table. A shorter close delay time is = required unless you lower the flow rate of the injectors by changing the = injector itself or lower the fuel pressure. The injector open time is = at least 2 ms or it doesn't open at all. =20 Steve Boese ------=_NextPart_000_009C_01C763CB.95854AC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
ED, George, Steve,
A strong contributor to this may lie in = the=20 fundamental design of the EC2.  It's output control is sinking = rather than=20 sourcing.  If it were sourcing the positive EMF would be switched = and the=20 other  side of the could would always be grounded, leaving a place = for the=20 coil breakdown current to go.  Well the controller is what it is, = so the=20 question become what can we do to work around the problem?  = Encoders are=20 used often in industrial applications,  these are generally = connected in a=20 sinking fashion just as the EC2.  In high frequency (encoder=20 pulses) applications the impedance of the input electronics is = often to=20 slow to bleed of the leading edge of the encoder on voltage before the = next=20 pulse cycle.  End result is that the input does not detect tithe = state=20 change.  The solution is very simple for the described situation is = very=20 simple.  Installing a pull down resistor between the sensor signal = line and=20 ground.  This technique is used with standard input electronics = with pulse=20 trains up to 50kHz, which translates to a cycle period of 20=B5S.
 
How does this translate to our = application? =20 If we were to add a pull down resistor in injector signal = line, which may=20 very well be a simple method to reducing the off delay time.  This = would of=20 course add a small increase in the current for the injector circuits, = but that=20 increase would likely be minimal.  The value of the resistor would=20 certainly need to be determined using factors such as Injector turn on = voltage,=20 turn off voltage, device current, etc.  IMO this may be a = simple=20 solution to the delay issue.
 
In the end I defer final = recommendations to Tracy,=20 who certainly knows the characteristics of his controller system better = than=20 I.
 
Joe
 
 
 
----- Original Message -----
From:=20 Steven = Boese
Sent: Saturday, March 10, 2007 = 11:44=20 PM
Subject: [FlyRotary] Re: The = truth??? /=20 Injector flow rate mystery solved

Ed and=20 George,

 

In my = plane, at=20 least, injector open times need to be less than 2 ms at idle and just = above=20 the staging point.  This = is not=20 possible with a minimum open time of 2 ms due to the delay on = closing.  You can program the EC2 for = less than=20 2 ms but the hardware is unable to do this.  That means that the problem = can=92t be=20 fixed with software or programming different values in the map = table.  A shorter close delay time = is required=20 unless you lower the flow rate of the injectors by changing the = injector=20 itself or lower the fuel pressure. =20 The injector open time is at least 2 ms or it doesn=92t open at = all.

 

Steve Boese

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