---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 08/10/08: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:29 AM - Re: Alternator part number? (Robert L. Nuckolls, III) 2. 11:38 AM - Re: Article from AOPA on Glass EFIS failures (Robert L. Nuckolls, III) 3. 05:13 PM - Re: Alternator part number? (Ken) 4. 05:28 PM - Re: I-Phone Inclinometer (rampil) 5. 10:40 PM - Re: Re: I-Phone Inclinometer (Etienne Phillips) ________________________________ Message 1 _____________________________________ Time: 07:29:12 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Alternator part number? > Followup: Another member on the List has turned me on to > the following website: > >http://www.motorcarparts.com/catalog.htm > Followup to the followup. I may have an opportunity to examine failure analysis data for various automotive alternators that would give us some insight as to the smoothest way to integrate these devices into OBAM aircraft. Does anyone has a part number to share taken from a label on their current installed alternator or perhaps off a carton or invoice for having purchased the alternator? I'd like to know what it is and perhaps a little background on how you selected and acquired the alternator. We can plug the numbers into the big data-base-in-the- sky and see what spits out. It may be significant, it may not . . . but interesting in any case. Bob . . . ________________________________ Message 2 _____________________________________ Time: 11:38:41 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Article from AOPA on Glass EFIS failures At 08:25 PM 8/6/2008 -0400, you wrote: > > >Hinde, Frank George (Corvallis) wrote: >>(Corvallis)" >> >>Ahh yes...As I tell my engineers who want every cool gadget going on >>their sysytems..."Every component is an expensive point of failure" Yeah, I recall a gray-beard telling me 30 years ago about what he called "the rule of tens". He was counseling me about specing 1% established reliability resistors even if the electrical performance wasn't needed. He said it cost us 50 cents to bring it in, $5 to find a bad one at the board level, $50 to find a bad one at the ATP level, $500 to find it on the airplane, and a whole lot more if somebody's airplane get's bent or people get hurt (1975 prices!). The value of good parts goes beyond the price of buying the part . . . more significant still was the value of not having a part there in the first place. Parts count reduction was a powerful tool for $risk$ reduction. Lines of code, quantities of parts . . . it's good not to have more than necessary to meet design goals.. >Proper software engineering requires the same sort of methodical, tedious >system review and modularity that we expect to put in our electrical >design. In the end, that is exactly what it is, a lot of tiny electrical >switches going off all over the place. The fault scenarios are often >difficult to identify. Even people who should know better often forget this. Yes, and the MBA/Regulatory solution to this is "standardize" whether it's DO-xxx, ACzzz, ISO9xxx, FARxxxetc. The concept is devilishly and deceptively simple. "Document the path to Nirvana and anyone who can read will achieve the golden goal." I've watched the production lines at local GA manufacturing erode from experienced skill and pride of craftsmanship to certificated ignorance and apathy. The same thing is happening in engineering. Nobody designs anything any more, they write specs (per the ISO approve P&P manual) and farm it out. Problem is that the folks they farm it out to are just as P&P driven as the folks who write the specs. When it doesn't work quite right, everyone gets that deer-in-the-headlights look while the customer of a $14M$ airplane is out in the lobby tapping his toe awaiting delivery. "This can't be happening . . . the specs say that it's supposed to work and yea verily, it must be so!" The poor sap who gets to write "real" code must follow the top-down design document that was mandated to him irrespective of his personal and perhaps accurate assessment of how bad it is. Managers of "The Word According to ISO" may personally worship individual abilities of a guy who can heard a tiny ball around a big field better than anyone else, or the strange but obviously talented inventor, the entertainer who enthralls thousands, or the guy who can pick up a toolbox and 'scope and seems to be able to fix anything. Yet if any individual working under the "Gospel According to ISO" strays from the path of documented excellence, he or she is promptly brought back in line . . . if not fired. If the likes of Edison, Kettering, Gates or Kay had been saddled with modern business and product development dogma, the technology we enjoy today would have a VERY different appearance and utility. The last two years of my tenure at H-B included an effort to fund and execute a real IR&D activity intended to produce a universal fuel gaging module. A device that could be programmed to work in anything from a Bonanza to the 4000. Even had a team of capable and willing participants lined up. "Nope, can't be messing with that kind of stuff. It's not our core competency." A year after I left, I participated in a response to a request for proposal for development of just such a gizmo. Eureka! I might get to work on this after all! We put the proposal in about 10 weeks ago and everybody was all smiles. It's been hung up in supply chain because the P&P manual doesn't cover some of the unique features of our proposal . . . (sigh) If Frank Hedrick were still running the show, we'd be flying our first-cut prototype by now and fine tuning performance based on real-time feedback from flight test pilots and instrumentation . . . not waiting for the top-down writers to conjure up a new route to Nirvana. Bob . . . ________________________________ Message 3 _____________________________________ Time: 05:13:27 PM PST US From: Ken Subject: Re: AeroElectric-List: Alternator part number? ND 100211-1680 which crosses to 612270 on the site. An industrial 40 amp unit that is small, light, and relatively modern. It was largely chosen for its low 40 amp output in case it ever ran away and to allow loading it down if the voltage was high. Then I found out about OVP protection. However all my lights and pitot heat can indeed load it higher than 40 amps which I like. I think it was around $150 new. 212 hours on it so far and rock steady at 14.3 volts. Unlike some newer units, it will draw field current anytime the IGN lead is powered, even if the alternator is not rotating. Ken Robert L. Nuckolls, III wrote: > > > >> Followup: Another member on the List has turned me on to >> the following website: >> >> http://www.motorcarparts.com/catalog.htm >> > > > > Followup to the followup. I may have an opportunity > to examine failure analysis data for various automotive > alternators that would give us some insight as to > the smoothest way to integrate these devices into > OBAM aircraft. > > Does anyone has a part number to share taken from > a label on their current installed alternator > or perhaps off a carton or invoice for having purchased > the alternator? I'd like to know what it is and perhaps > a little background on how you selected and acquired > the alternator. > > We can plug the numbers into the big data-base-in-the- > sky and see what spits out. It may be significant, > it may not . . . but interesting in any case. > > Bob . . . > ________________________________ Message 4 _____________________________________ Time: 05:28:23 PM PST US Subject: AeroElectric-List: Re: I-Phone Inclinometer From: "rampil" Actually Ron has a reasonable question. All of the modern inertial platforms use MEMS-based accelerometers not gyros as sensors. The problem with MEMS chips is that they drift and require correction or compensation. Often the drift correction can be done with a GPS ala BlueMountain, etc. So... some enterprising programmer could, with the new GPS capabilities in the development software now in beta, create an emergent AI, better in theory that the GPS only system like in the Garmin 496. I'm not an engineer, but I played one in grad school for 4 years -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=197792#197792 ________________________________ Message 5 _____________________________________ Time: 10:40:32 PM PST US Subject: Re: AeroElectric-List: Re: I-Phone Inclinometer From: Etienne Phillips On 11 Aug 2008, at 2:25 AM, rampil wrote: > > All of the modern inertial platforms use MEMS-based accelerometers > not gyros as sensors. The problem with MEMS chips is that they drift > and require correction or compensation. Often the drift correction > can be done with a GPS ala BlueMountain, etc. > All the electronic systems I've come across (MGL and Dynon in particular) use both accelerometers and "solid-state" gyros, and some even use an electronic compass and airspeed. The SS gyros only output the rate of change of direction whereas the accelerometers, compass and airspeed measurements give an absolute value at any time. If the gyros have even a very slight offset error, this will be integrated over time to be a constant change in direction, which is compared Etienne ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.