X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 08 Jan 2008 15:23:25 -0500 Message-ID: X-Original-Return-Path: Received: from smtp119.sbc.mail.sp1.yahoo.com ([69.147.64.92] verified) by logan.com (CommuniGate Pro SMTP 5.2c4) with SMTP id 2635258 for lml@lancaironline.net; Mon, 07 Jan 2008 19:09:04 -0500 Received-SPF: none receiver=logan.com; client-ip=69.147.64.92; envelope-from=elippse@sbcglobal.net Received: (qmail 94676 invoked from network); 8 Jan 2008 00:08:15 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=sbcglobal.net; h=Received:X-YMail-OSG:Message-ID:From:To:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=AY5li7QmoBH3CApkkeiloXZtVOhmM7623UqJ6TPcwEIkZYXD4MjRGeKpE3Ab6jHfToTnScUkNUNk16pwo+1Sv/z52UmsNRagmshrhHEKaowJkCF0DMr9qrDlGdBhY/icmNXHFqhK4Krmmw3Qu3K/1sFZ2hG3X4wjyrgDkip/9cw= ; Received: from unknown (HELO Computerroom) (elippse@sbcglobal.net@75.15.159.163 with login) by smtp119.sbc.mail.sp1.yahoo.com with SMTP; 8 Jan 2008 00:08:14 -0000 X-YMail-OSG: NNrb.CAVM1ljkuTWKhfnpC6UVH4QluLEM0GjEVExOr3E_YwFVoEFcUyHg1UXtlz9PLwaYiYFCg-- X-Original-Message-ID: <003301c8518a$966c8450$a39f0f4b@Computerroom> From: "Paul Lipps" X-Original-To: "Marv Kaye" Subject: EI cont. X-Original-Date: Mon, 7 Jan 2008 16:08:24 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0030_01C85147.87D21880" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_0030_01C85147.87D21880 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable ...plus, I told Klaus at the outset that the only way I would design a = micro-based ignition is if it was triply redundant with majority voting = on the outputs. And that he better be ready to do Monte-Carlo = simulations with all kinds of different things going wrong to demostrate = that it would not harm the engine or pilot when some sensor or transient = failure occured. I really like computers; I use one all the time to = design my props. I've worked with them since 1958! But some of the = problems I've had have been with software routines programmed by others, = that took control or turned off interrupts. 'Had that last happen on an = Atlas flight! But I have to consider what the software in a = single-processor ignition or fuel injection system would do if a cosmic = ray/high energy particle came burrowing through the solid-state program = memory and changed the state of one bit. For those who don't know about = this, it's referred to as an SEU, a single-event upset. That's why space = hardware has to be radiation hardened. But it can happen at sea-level = too, but occurs more often the higher you go. It also is more of = problem with with the more miniature, smaller-junction size devices. = Since an ignition system is a relatively slow system, it's better to use = the larger, slower devices which have greater immunity to SEUs due to = their junction size. My rule is to not use faster gates than what are = necessary! These are some of the things you should ask someone who wants to = sell you a single-processor system. BTW, Klaus tells me that one of his = customers had a lightning strike that let the smoke out of his avionics = but the Plasma kept on ticking. ------=_NextPart_000_0030_01C85147.87D21880 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
...plus, I told Klaus at the outset that the = only way I=20 would design a micro-based ignition is if it was triply redundant with = majority=20 voting on the outputs. And that he better be ready to do Monte-Carlo = simulations=20 with all kinds of different things going wrong to demostrate that it = would not=20 harm the engine or pilot when some sensor or transient failure = occured. I=20 really like computers; I use one all the time to design my props. I've = worked=20 with them since 1958! But some of the problems I've had have been with=20 software routines programmed by others, that took control or turned = off=20 interrupts. 'Had that last happen on an Atlas flight! But I have to = consider what the software in a single-processor ignition or fuel = injection=20 system would do if a cosmic ray/high energy particle came burrowing = through=20 the solid-state program memory and changed the state of one bit. = For those=20 who don't know about this, it's referred to as an SEU, a single-event = upset.=20 That's why space hardware has to be radiation hardened. But it can = happen at=20 sea-level too, but occurs more often the higher you go. It also is more = of =20 problem with with the more miniature, smaller-junction size devices. = Since an=20 ignition system is a relatively slow system, it's better to use the = larger,=20 slower devices which have greater immunity to SEUs due to their junction = size.=20 My rule is to not use faster gates than what are necessary!
    These are some of the things = you should=20 ask someone who wants to sell you a single-processor system. BTW, Klaus = tells me=20 that one of his customers had a lightning strike that let the smoke out = of his=20 avionics but the Plasma kept on ticking.
------=_NextPart_000_0030_01C85147.87D21880--