AeroElectric-Archive.digest.vol-eu

September 09, 2005 - September 20, 2005



      
      The plane is getting painted, all the small parts are painted yellow. The 
      wings are in the paint shop, took them there today. They will be painted 
      yellow in the next two or three days.
      The windshield is due to be installed as soon as a small welding job can be 
      done on the roll bar which serves as the windshield support. There is 
      actually very little work left to be done but now the paper trail with the 
      government begins.
      
      The graphic is a rough draft of the intended final design.
      
      I know the next few weeks will be tough enough,  Hang in there lad.
      
      Unc
      
      
      ----- Original Message ----- 
From: "LarryRobertHelming" <lhelming(at)sigecom.net>
Subject: Re: mini jack source
> > > To test your theory, you should remove the jack from the panel and attempt > to use it without it touching anything to eliminate the grounding > possibility. > > Indiana Larry > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > " Happiness: like a butterfly, when pursued, > is always beyond our grasp, but which, > if one sits quietly, may light upon you." > > Nathanial Hawthorn > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > ----- Original Message ----- > From: "Robert Dickson" <robert@thenews-journal.com> > To: "Aeroelectric List List" > Subject: AeroElectric-List: mini jack source > > >> <robert@thenews-journal.com> >> >> I'm looking for a source for a 1/8 inch stereo mini plug jack that can >> be mounted in my metal panel and isolated from ground. I'm using it for >> a music input to my Garmin 340 audio panel. Currently I have a cheapo >> Radio Shack jack installed and I can hear the strobes (power packs in >> wing tips) pulsing when I turn on the high gain switch. I may have >> another problem but I figure that until I get that jack isolated I >> won't know. The jack I'm using is just barely long enough to make it >> through the panel, so just adding washers to it isn't an option. >> So, does anyone know where I can find a jack with isolating washers >> that I can mount in my panel? Or, is there another way to skin this cat >> that won't look too junky in my nice clean panel? >> >> thanks, >> Robert Dickson >> RV-6A 130 hrs. >> >> >> > > > ________________________________________________________________________________
Date: Sep 09, 2005
From: Wes Knettle <wsknettl(at)centurytel.net>
Subject: 24 (28) vs 12 (14) volt systems
2.60 SUBJ_PAREN_NUMS Subject has several parenthesized numbers I'm going to try to answer a question with a question. Cessna 185's made the switch from 12 volt (G35 battery) to 24 volt (G242 battery) in the 70's. Otherwise the aircraft are the same with the same IO-520-D engine. I have maintained these 185's for 20 years. A hot start on a 12 volt 185 is a lot slower than a hot start on a 24 volt 185. I have seen this also on the Lycoming powered equipment. As for the evolution of DC mobile electrical systems it seems to me the goal has always been more cranking power and less weight. 6 volt cars crank slower than 12 volt cars and 12 volt cars crank slower than 24 volt cars. I have proven this over and over again with the Willys L134 engined jeeps which from 1941 thru 1971 came with 6, 12 and 24 volt systems. The weight savings comes in the form of lighter gage wire for the higher voltages and lighter weight motors and generators for higher voltages. It is now rumored that the auto industry is heading towards a 42 volt system. If cost savings by using 12 volt auto electrical parts is the only basis for selecting 12 volt for your project then by all means do so but there must be adequate improvements in performance to justify the 24 volt systems where cost is not the only consideration? As for sources of parts remember the military equipment standard has been 24 volts since 1950. There are tons of surplus military 24 volt electrical out there and it's cheap. Wes K > > ________________________________________________________________________________
From: "Frank Stringham" <fstringham(at)hotmail.com>
Subject: Use a 28vdc alternator in 14vdc system?
Date: Sep 09, 2005
Bruce Probably another reason I will not buy a span can cessna............... Frank @ SGU and SLC and also remember good friends dont't let their friends fly plastic planes!!!Sorry I just couldn't resist!!!!!!!!!!!!!!!!!! >From: "Bruce Gray" <Bruce(at)glasair.org> >Reply-To: aeroelectric-list(at)matronics.com >To: >Subject: RE: AeroElectric-List: Use a 28vdc alternator in 14vdc system? >Date: Thu, 8 Sep 2005 22:56:40 -0400 > > >How many 14v airplanes does RAC or Cessna make today? Zip..Nada..Zero > >Bruce >www.glasair.org > > >-----Original Message----- >From: owner-aeroelectric-list-server(at)matronics.com >[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert >L. >Nuckolls, III >To: aeroelectric-list(at)matronics.com >Subject: RE: AeroElectric-List: Use a 28vdc alternator in 14vdc system? > > > > > > > > >28v is used in the trucking industry also. Nothing wrong with 14v, I just > >like more power and I don't like my panel to go dim at night when I lower > >the gear. > > More power to do what? The only 24 volt system I helpped > put in a long-ez was about 20 years ago when the builder > wanted electric heat in the cabin. We put a 24-volt > 100A system in and he still didn't have all the heat he > needed. > > A 14v, 60A system is good for 650W with charging reserves. > How much do you need that cannot be met with this source? > Dimming of the panel lights can be offset with REGULATING > dimmers like the ones we used to sell and now sold by > B&C. > > Bob . . . > > ________________________________________________________________________________
From: "Craig Berland" <cberland(at)systems3.net>
Subject: Re: Use a 28vdc alternator in 14vdc system?
Date: Sep 09, 2005
> > > >How many 14v airplanes does RAC or Cessna make today? Zip..Nada..Zero > > > >Bruce > > And just why do you suppose that is? > > Bob . . . > The reason is they are lighter and cheaper, but you knew that. General Motors engineers have wanted a 50 or 60 volt system for years, but that is a lot of momentum to change. I have 24v and 100amp to run an EEDS de-ice system and a hot prop on my IV-P. Craig Berland ________________________________________________________________________________
Date: Sep 09, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Use a 28vdc alternator in 14vdc system?
> >Oh, the usual - commonality across production lines. You got it! >And it's better. (grin) There IS a physics component to the decision too . . . the capabilities of starters (1940's technology) and batteries (1900's technology) of the time were such that total loop resistance (losses) were less significant for a 24v system. With the much more capable lightweight starters (1980's) and recombinant gas batteries (1980's) it's easy to drive effects of loop resistance down to the same levels that 24v systems enjoyed 40 years ago. The major reason Cessna went all-28 was to use one alternator, one regulator and only two different batteries across an entire product line. Hence, even the lowly C-150 "enjoyed" superior cranking performance compared to any other airplane in the product line. How about cost-of-ownership? Cessna and contemporaries had very little control over cost of ownership decisions due to a then restrictive (and today oppressive) regulatory environment. Ford can make a $2 change to a car to reduce cost of ownership and recoup that $2 in very tiny increments over millions of cars. I'm working a change to a 20 year old design on a bizjet where a part has gone obsolete (the only thing that FORCES change) on an assembly with a bill of materials of under $100. The new part is form-fit-function replacement and has nothing to do with flight safety. None the less, after all the no-value-added hoops are jumped, all the reports are written and blessed, my company will have spent about $100,000 on a change that doesn't even improve the cost of ownership for that airplane . . . it only just preserves the decades old status of the system. The part will be built outside and probably cost my company $1000. It will fall into an ISO, FAA, FTC, EPA, OSHA, AFLCIO, IRS, etc. approved distribution system and go onto the customer's airplane for about $2,000 to $2,500. These same conditions prevail on virtually all certified aircraft. One would like to believe that everything we've seen roll of the assembly lines of these factories is based on good science, well considered economics, service to the customer and a controlling desire to improve customer perceptions of value. Nothing could be further from the truth. Some really big buzz programs circulating around the industry intended to improve on perceptions of value are considering things like high-speed Internet in the cabin, massage seats, heated seats, neat passenger operated electro-whizzies for the entertainment systems, etc. In the mean time, that $100 obsolete part problem along with all it's lesser and greater cousins are eating our collective lunch (supplier and customer). The only folks making out like bandits are those who receive salaries to make life miserable for those who produce and add value while adding no value of their own (and taking no responsibility for the current state of affairs). There is a grain of truth to many of the things we've come to believe about aviation's design and marketing decisions. I can tell you first hand that MOST of those decisions are NOT based in good engineering or science nor are they permitted to evolve with the new technologies. There were some demonstrated advantages of moving to 24 volt for some airplanes to offset starting problems. Most if not all of those reasons have evaporated under the influence of modern components. This opens the door for very cost effective designs for OBAM aircraft based largely on components and lessons learned in the automotive and consumer electronics industries who have to had perceptions of real value to their products or die. Certified aviation lives in a bubble of artificial life support. The 42v car is an interesting dream. It's not going to be easy. As the layers of the onion are peeled back and underlying simple-ideas are exposed, there are plenty of unanticipated dragons to slay. But know that the reason for the higher voltage is only mildly influenced by a desire for lighter wire bundles. The major drive is to produce more POWER for what is anticipated to be an increasingly power hungry set of systems. It's unlikely that many of these systems will find desire or favor with the OBAM aircraft community but who knows? Things have changed greatly in the last 20 years, we can only expect still greater changes in the next 20 years. Those changes will show up in airplanes for new kids on the block (Honda, Eclipse, Quest, et. als.) Given present circumstances, it's doubtful as to how much of it will show up on BePiCesMo products. Bob . . . ________________________________________________________________________________
From: "Eric M. Jones" <emjones(at)charter.net>
Subject: Re: 42 vs 24 vs 12 volt systems
Date: Sep 09, 2005
I remember when cars went from 6V to 12V. As I remember the chief issue was contacts and connections. I also remember when microprocessors went from 5V to 3V. But real airplanes and real men use three-phase 115VAC 400Hz. It should be possible to write a mountain of data into a spreadsheet and derive the lowest cost, lowest weight, most reliable system, but I am certain those three characteristics would conflict. Bob's point about the relative costs of automotive components is good advice. If you went to buy your electrical system from the 28V-Store, you'd find that most of the stuff was expensive, certificated (remember that they certify the milk, but they certificate the cow) and the selection would not be all that large. The 14V-Store has all the bargains and selection to be sure. Is the auto industry going to 42V? I was spreading that rumor too. More recent rumors show advantages to staying at 14V; because LED lighting systems, microprocessors, and mosfets solid-state switches, are more efficient and reliable at lower voltages, while the use of single-wire power busses makes the argument about smaller wire gauges less important. The integration of the starter and alternator works fine at 14V too. The extinguishing of electrical contact arcs is a difficult problem at 42V too. In short, the advantages of 28V don't seem to warrant the increased expense. I dream of the three-phase 115VAC 400Hz system with distributed down converters and motors the size of your pinky, four tiny wires snaking through the airplane driving beams of light piercing the darkness....then I wake up. Regards, Eric M. Jones (14VDC Glastar 5540 N5EJ still a-building) www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 (508) 764-2072 "The problem with the world is that only the intelligent people want to be smarter, and only the good people want to improve." - E Stobblehouse ________________________________________________________________________________
Date: Sep 09, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Use a 28vdc alternator in 14vdc system?
> > > > > > > > >How many 14v airplanes does RAC or Cessna make today? Zip..Nada..Zero > > > > > >Bruce > > > > And just why do you suppose that is? > > > > Bob . . . > > >The reason is they are lighter and cheaper, but you knew that. The delta-cost of components is trivial. Further, overall weight differences are quite small; the great weight savings for raising system voltage in small aircraft simply didn't materialize . . . although there are many vocal purveyors of the weight savings myth (who are unable to support it with fact). See: page 6-12 of http://www.aeroelectric.com/articles/richter/response_1.pdf and pages 5-6 of http://www.aeroelectric.com/articles/richter/response_2.pdf >General Motors engineers have wanted a 50 or 60 volt system for years, >but that is a lot of momentum to change. I have 24v and 100amp to run an >EEDS de-ice >system and a hot prop on my IV-P. EXACTLY! You have a driving need for 28v system NOT for lighter wire, NOT for better cranking but for POWER. You're running a lot of electric heat and accessories with some extraordinary demands. Do you have an air-conditioner too? The builder needs to look at a 60A, 14v alternator (840 watts) and decide what system requirements may require continuous loads that exceed about 75% of that value (25% headroom for battery charging). So, if 630 watts is not enough to run things, then one should consider whether or not a 100A alternator will suffice or is it better to go 28V at 60A (1680 watts) or even the system you've installed (2400 watts). Every change has trade-offs. Excursions out of the 14v world pushes you out of automotive technologies and toward aircraft technologies (artificially inflated costs). In your case, the tradeoffs were acceptable and necessary to meed your overall energy requirements set by rational design goals. Your airplane is representative of perhaps 1 to 2% of the OBAM aircraft fleet. For 98% of the builders to get wrapped around the 14/28 axle is (in my never humble opinion) a waste of time and sometimes emotional resources. Bob . . . ________________________________________________________________________________
From: "Paul McAllister" <paul.mcallister(at)qia.net>
Subject: Re: 42 vs 24 vs 12 volt systems
Date: Sep 09, 2005
Hi all, I often read about some of the power requirements folks are demanding for there aircraft and wonder why. For each 746 watts of energy we consume means one horsepower less that drives the propellor. It is possible to build very economical systems (from a power consumption perspective) by using various components such as semi conductor contactors, LED lighting, pitot heat systems as described by Eric and so on. With some careful thought I was able to build a system that has an in flight consumption of 8.6 amps at 13.8 volts...... the need for a 28 volt system escapes me. Paul ________________________________________________________________________________
Date: Sep 09, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Use a 28vdc alternator in 14vdc system?
> >Sure, but how much automotive stuff are you planning on using? Most >modern avionics take anything between 10 and 30 volts. 28v halogen >bulbs don't cost any more than the 12v version although they're less >common. Battery chargers are out there, try Concord. This isn't about our ability to craft any system of any voltage and do it well based on our understanding of the simple-ideas and costs (tradeoffs) of implementing combinations of simple-ideas . . . >I'm curious, does anyone have any reason why 28v is not a good idea >besides you can't use 12v automotive parts? That's the only reason I've >ever heard as to why people prefer 12v. I wouldn't call it a "bad" idea . . . just not necessary in terms of power requirements for the vast majority of OBAM aircraft and certainly not justified in terms of weights. To be sure, "justification" is subjective. I had a builder write me a few years ago and listed in detail the differences between a 14 and 28 volt system to meet his design goals. A high priority goal was weight and yes, he did document a savings of about 2 pounds. Assuming his calculations were correct, he was pleased with both the weight savings -AND- and costs to enjoy those savings. The decision is a GOOD one only if the individual making the decision sets the goals and then understands and accepts the tradeoffs to meet those goals. Folks have misunderstood my down-side comments about 28v as a goal to discourage use of the higher voltage. I wouldn't try to discourage anyone of meeting well considered design goals and acceptance of the costs based on understanding. Bob . . . ________________________________________________________________________________
From: Robert Dickson <robert@thenews-journal.com>
Subject: Re: mini jack source
Date: Sep 09, 2005
this is a good and obvious test, one I should of thought of myself. I just performed this test and, sure enough, the strobe noise went away when the jack was out of the panel. So, I'm back to my original question which is how to elegantly isolate this jack from my panel. Since I have a hole already drilled right where I'd like the jack I'd really like a jack with isolating washers just like my headset jacks, if such a creature exists. Robert Dickson RV-6A On Sep 8, 2005, at 8:35 PM, N1deltawhiskey(at)aol.com wrote: In a message dated 08-Sep-05 16:26:25 Pacific Standard Time, robert@thenews-journal.com writes: Or, is there another way to skin this cat that won't look too junky in my nice clean panel? Robert, Have you tried duplicating the circumstances with the jack dismounted from the panel? Does it cure the problem? If not, I would be skeptical that simply isolating it from the panel will be the solution. Doug Windhorn ________________________________________________________________________________
Date: Sep 09, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: mini jack source
><robert@thenews-journal.com> > >this is a good and obvious test, one I should of thought of myself. > >I just performed this test and, sure enough, the strobe noise went away >when the jack was out of the panel. Beware the evil ground loop! >So, I'm back to my original question which is how to elegantly isolate >this jack from my panel. Since I have a hole already drilled right >where I'd like the jack I'd really like a jack with isolating washers >just like my headset jacks, if such a creature exists. Got access to a lathe? You can cut some washers out of a good machinable plastic stock . . . Like Delrin. You might also consider labeling your jack with a rectangular engraved plastic placard like name plates are made from. You can oversize the hole behind the placard to clear the jack and allow the jack to be supported by the placard and provide insulation as well. There are some nice double-sided-sticky tapes to mount the placard. How thick is your panel and how much thicker could it be and still allow the jack to be installed with it's existing bushing length? Bob . . . ________________________________________________________________________________
From: "Jim Baker" <jlbaker(at)telepath.com>
Date: Sep 09, 2005
Subject: Re: mini jack source
> I just performed this test and, sure enough, the strobe noise went > away when the jack was out of the panel. > > So, I'm back to my original question which is how to elegantly isolate > this jack from my panel. Look for a company called Small Parts Inc. online. Search for shoulder washer...made of nylon. For those interested in unique small parts, get their free catalog. Jim Baker 580.788.2779 '71 SV, 492TC Elmore City, OK ________________________________________________________________________________
Date: Sep 09, 2005
From: PWilson <pwmac(at)sisna.com>
Subject: Re: Use a 28vdc alternator in 14vdc system?
Bob, and bigger alternators are available, for example: 14v alternators for the auto after market come in 150a (2100 watts) - a Denso, and 200a (2800 watts) - a Powermaster. Lots of power out there at 14v if one needs it. Regards, Paul ================= At 09:55 AM 9/9/2005, "Robert L. Nuckolls, III" wrote: >---snip--- > EXACTLY! You have a driving need for 28v system NOT > for lighter wire, NOT for better cranking but for > POWER. You're running a lot of electric heat and accessories > with some extraordinary demands. Do you have an air-conditioner > too? > > The builder needs to look at a 60A, 14v alternator (840 watts) > and decide what system requirements may require continuous > loads that exceed about 75% of that value (25% headroom for > battery charging). So, if 630 watts is not enough to run > things, then one should consider whether or not a 100A alternator > will suffice or is it better to go 28V at 60A (1680 watts) > or even the system you've installed (2400 watts). ________________________________________________________________________________
From: Robert Dickson <robert@thenews-journal.com>
Subject: Re: mini jack source
Date: Sep 09, 2005
Bob the placard is actually a good idea, I think. I'm using a custom made placard for my switch row which is based closely on your switch clusters. It's not even glued on, just held in place by the switch nuts. If you give a decent trophy shop a vector file they can cut almost anything you want *exactly* where you want it. I get compliments on my switch labels, thanks to you. The darned jack just isn't long enough to clear anything but the .063 panel and still get the nut on. I'm not even using a washer. The placard material is generally even thicker than .063 (I think) so while it would isolate the jack I'd probably still have a problem mounting it. There must a jack out there some place that has a longer length. I'll keep looking. At least this is just a problem with the entertainment system! Thanks for your help. Robert Dickson Rv-6A On Sep 9, 2005, at 1:38 PM, Robert L. Nuckolls, III wrote: > <robert@thenews-journal.com> > > this is a good and obvious test, one I should of thought of myself. > > I just performed this test and, sure enough, the strobe noise went away > when the jack was out of the panel. Beware the evil ground loop! > So, I'm back to my original question which is how to elegantly isolate > this jack from my panel. Since I have a hole already drilled right > where I'd like the jack I'd really like a jack with isolating washers > just like my headset jacks, if such a creature exists. Got access to a lathe? You can cut some washers out of a good machinable plastic stock . . . Like Delrin. You might also consider labeling your jack with a rectangular engraved plastic placard like name plates are made from. You can oversize the hole behind the placard to clear the jack and allow the jack to be supported by the placard and provide insulation as well. There are some nice double-sided-sticky tapes to mount the placard. How thick is your panel and how much thicker could it be and still allow the jack to be installed with it's existing bushing length? Bob . . . ________________________________________________________________________________
Date: Sep 09, 2005
From: Ken <klehman(at)albedo.net>
Subject: Re: Use a 28vdc alternator in 14vdc system?
I believe the answer is both. For a device that is mostly current limited I would not expect much difference between 12 and 14 volts. Ken Mickey Coggins wrote: > > > >> The builder needs to look at a 60A, 14v alternator (840 watts) >> ... >> >> > >Are most alternator current specifications given assuming >14v? I'm planning on using this one: > >http://www.ecae.com/alt1.html > > 2025 Ultra Mini Alternator > >The text says this: > >East Coast Auto Electric UltraMini 12 Volt Series MINI-ALTERNATOR >The UltraMini Alternator is the smallest in our line. It weights only 6 >Lbs. and has an output of 55 amps. > >Is there a way I can find out if the 55 amps number is assuming >12v or 14v? > >Thanks, >Mickey > > > ________________________________________________________________________________
From: <robert.mccallum2(at)sympatico.ca>
Subject: DC to DC converter
Date: Sep 09, 2005
Hi all; Does anyone have a schematic available, or know of a source for a small, inexpensive 12 VDC to 24 VDC converter capable of supplying approximately 30Ma @ 24 VDC? I do not want a high power device as this will be a dead loss system operating from a 4 Amp-Hr VRLA battery and long operating time is important. (the less draw on the battery the better) The device I need to operate is a light source rated 10 to 30 VDC which is part of a photocell system. This is currently operating successfully on 12 volts but at this voltage doesn't provide quite enough range. I've demonstrated to myself that 24 volts increases the range sufficiently, and I suppose that I could double up on the batteries to get the 24 volts but this creates other difficulties of size and complexity which we won't delve into. Thanks in advance if anyone can help. Bob McC ________________________________________________________________________________
Date: Sep 09, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: mini jack source
> > > I just performed this test and, sure enough, the strobe noise went > > away when the jack was out of the panel. > > > > So, I'm back to my original question which is how to elegantly >isolate > > this jack from my panel. > >Look for a company called Small Parts Inc. online. Search for >shoulder washer...made of nylon. > >For those interested in unique small parts, get their free catalog. Good item Jim, I'd forgotten about those guys. I've used them a lot in the past for small gears and shafts. Bob . . . ________________________________________________________________________________
From: "Mike" <mlas(at)cox.net>
Subject: mini jack source
Date: Sep 09, 2005
> <robert@thenews-journal.com> > > this is a good and obvious test, one I should of thought of myself. > > I just performed this test and, sure enough, the strobe noise went away > when the jack was out of the panel. Beware the evil ground loop! > So, I'm back to my original question which is how to elegantly isolate > this jack from my panel. Since I have a hole already drilled right > where I'd like the jack I'd really like a jack with isolating washers > just like my headset jacks, if such a creature exists. You could counter bore the hole and mount the jack on to some non-conductive material and then bond it to the back of the panel. This way you would fix the ground problem and the reach problem. And if you did a nice job counter boring (in this process over sizing the hole) it would look flush mounted. Mike Larkin PZL TS-11 Iskra Lancair Legacy Kitfox IV A-320 ________________________________________________________________________________ Received-SPF: softfail (mta7: domain of transitioning trigo(at)mail.telepac.pt does not designate 85.138.31.28 as permitted sender) receiver=mta7; client_ip=85.138.31.28; envelope-from=trigo(at)mail.telepac.pt;
From: "Carlos Trigo" <trigo(at)mail.telepac.pt>
Subject: Re: Battery is not charging
Date: Sep 10, 2005
Bill, Matt, Bob Thanks for your answers. From: "Matt Prather" <mprather(at)spro.net> > > Do you know if the system ever actually charged the battery - kept the bus > voltage above 14v? In other words, was the system wired correctly? Yes. Since 1999 > When you say "measuring the generator output" what do you mean? With the > engine running? Yes, at idle but also at around 2500RPM. But yesterday, when we measured between the 2 yellow wires of the generator not connected to the system, we got 0 (zero, nada), therefore the down indicated conclusion. > If you don't have a schematic of the system, draw > one up - take a notepad, pencil and DMM to the hangar and doodle > it out > nothing fancy. Compare what's doodled to what's on one of > the Bob's Rotax diagrams. Even if the system is designed/installed > okay, the exercise will help you debug the system. I'll try to do it, because the iniyial builder didn't do it and I have none. > Does the system have an alternator disconnect relay? No "Robert L. Nuckolls, III" wrote: > Get the battery tender. Hook it up for 24 hours or more. Fly the > airplane while watching voltage and report your findings back > to us. It would also be helpful to have an alternator loadmeter > installed so that you can see if the alternator is "working hard" > or "broke". I am going to try this one, before dismounting the generator from the engine. But from our last measuring, as indicated above, we believe the ROTAX alternator/generator has really passed away... That means 480 euros($600) + labour! Thanks again Carlos ________________________________________________________________________________
From: "Bill Denton" <bdenton(at)bdenton.com>
Subject: Battery is not charging
Date: Sep 10, 2005
Could someone possibly list the drawing numbers for "the Bob's Rotax diagrams"? Thanks! -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Carlos Trigo Subject: Re: AeroElectric-List: Battery is not charging Bill, Matt, Bob Thanks for your answers. From: "Matt Prather" <mprather(at)spro.net> > > Do you know if the system ever actually charged the battery - kept the bus > voltage above 14v? In other words, was the system wired correctly? Yes. Since 1999 > When you say "measuring the generator output" what do you mean? With the > engine running? Yes, at idle but also at around 2500RPM. But yesterday, when we measured between the 2 yellow wires of the generator not connected to the system, we got 0 (zero, nada), therefore the down indicated conclusion. > If you don't have a schematic of the system, draw > one up - take a notepad, pencil and DMM to the hangar and doodle > it out > nothing fancy. Compare what's doodled to what's on one of > the Bob's Rotax diagrams. Even if the system is designed/installed > okay, the exercise will help you debug the system. I'll try to do it, because the iniyial builder didn't do it and I have none. > Does the system have an alternator disconnect relay? No "Robert L. Nuckolls, III" wrote: > Get the battery tender. Hook it up for 24 hours or more. Fly the > airplane while watching voltage and report your findings back > to us. It would also be helpful to have an alternator loadmeter > installed so that you can see if the alternator is "working hard" > or "broke". I am going to try this one, before dismounting the generator from the engine. But from our last measuring, as indicated above, we believe the ROTAX alternator/generator has really passed away... That means 480 euros($600) + labour! Thanks again Carlos ________________________________________________________________________________
From: "Jim Baker" <jlbaker(at)telepath.com>
Date: Sep 10, 2005
Subject: Re: Battery is not charging
> > When you say "measuring the generator output" what do you mean? > > With the engine running? > > Yes, at idle but also at around 2500RPM. But yesterday, when we > measured between the 2 yellow wires of the generator not connected to > the system, we got 0 (zero, nada), therefore the down indicated > conclusion. Carlos, You do know that the output from the two yellow wires will be AC? A separate rectifier is used to convert to DC. If measuring AC with digital multimeter set to DC you'll get 0 (zip,nada)....... Jim Baker 580.788.2779 '71 SV, 492TC Elmore City, OK ________________________________________________________________________________ Received-SPF: softfail (mta7: domain of transitioning trigo(at)mail.telepac.pt does not designate 85.138.31.28 as permitted sender) receiver=mta7; client_ip=85.138.31.28; envelope-from=trigo(at)mail.telepac.pt;
From: "Carlos Trigo" <trigo(at)mail.telepac.pt>
Subject: Re: Battery is not charging
Date: Sep 10, 2005
----- Original Message ----- From: "Jim Baker" <jlbaker(at)telepath.com> Subject: Re: AeroElectric-List: Battery is not charging > Carlos, > > You do know that the output from the two yellow wires will be AC? > A separate rectifier is used to convert to DC. If measuring AC with > digital multimeter set to DC you'll get 0 (zip,nada)....... > > > Jim Baker Thanks Jim To be honest, I didn't know, but the electric guy who is helping me does know that. Carlos ________________________________________________________________________________
Date: Sep 10, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Battery is not charging
> >Could someone possibly list the drawing numbers for "the Bob's Rotax >diagrams"? > >Thanks! Figure Z-16 in http://aeroelectric.com/articles/Rev11/AppZ_R11C.pdf BTW, if you have no output between the yellow leads from the alternator windings, there is an open circuit. Can you SEE the windings? They should be a dark caramel color. Do any wires wound around the poles of the stator winding look or smell burned? Your existing stator coil might be repairable if it's just a broken wire. Bob . . . ________________________________________________________________________________
Date: Sep 10, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Battery is not charging
> > > >----- Original Message ----- >From: "Jim Baker" <jlbaker(at)telepath.com> >To: >Subject: Re: AeroElectric-List: Battery is not charging > > > > Carlos, > > > > You do know that the output from the two yellow wires will be AC? > > A separate rectifier is used to convert to DC. If measuring AC with > > digital multimeter set to DC you'll get 0 (zip,nada)....... > > > > > > Jim Baker > >Thanks Jim > >To be honest, I didn't know, but the electric guy who is helping me does >know that. Oh, I mis-read one of the messages. Jim is dead on, you DO need to know the value of AC voltage coming off the stator winding's yellow leads. When I misunderstood the voltage to be zero, I was surprised. This coil assembly is quite robust. Failure to charge is more likely to be a problem with the rectifier/regulator. Bob . . . ________________________________________________________________________________
From: <ceengland(at)bellsouth.net>
Subject: Re: Use a 28vdc alternator in 14vdc system?
Date: Sep 10, 2005
> > From: "Bruce Gray" <Bruce(at)glasair.org> > Date: 2005/09/08 Thu PM 09:56:40 CDT > To: > Subject: RE: AeroElectric-List: Use a 28vdc alternator in 14vdc system? > > > How many 14v airplanes does RAC or Cessna make today? Zip..Nada..Zero > > Bruce > www.glasair.org Do you fly a Cessna or RAC a/c? Why is their opinion better for electrical systems if it's not better for a/c selection? ;-> Charlie ________________________________________________________________________________
From: "Dave & Brenda Emond" <d_emond(at)mweb.co.za>
Subject: Re: RV 10 wiring architecture
Date: Sep 10, 2005
I am a non electric guy, starting out from scratch. I was hoping to get answers and opinions on the following questions. How are Cessna, Mooney, Pipers ect wired up. Are they dual battery and dual alternator? I want to keep my RV10 practical, and careful not to overdo the redundancy part, keep it simple. I will in all probability end up with an electric panel, no vacuum. I like the Grand Rapids system, Chelton is a bit too far away in $$$ terms. I would probably back up with a Dynon, with an internal Nicad. I will be running LASAR magneto's. My first thoughts are single Alternator and single battery? All suggestions and points of view are appreciated. Dave Emond ________________________________________________________________________________
Date: Sep 10, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> system?
Subject: Re: Use a 28vdc alternator in 14vdc
system? > > > > > > From: "Bruce Gray" <Bruce(at)glasair.org> > > Date: 2005/09/08 Thu PM 09:56:40 CDT > > To: > > Subject: RE: AeroElectric-List: Use a 28vdc alternator in 14vdc system? > > > > > > How many 14v airplanes does RAC or Cessna make today? Zip..Nada..Zero > > > > Bruce > > www.glasair.org >Do you fly a Cessna or RAC a/c? Why is their opinion better for electrical >systems if it's not better for a/c selection? ;-> Gently Charlie, we know the BePipCesMo guys are hard pressed just to stay in business under the worst of economic and working conditions; making detailed evolutionary refinements in on-board systems is simply impossible. Virtually EVERY decision for making changes has to be made under the albatross of, "what will it cost us to get dispensation and blessings from the East?" I'm told the cost of implementing a change to one sheet of paper describing a part of our products can cost 5 to 7 $thousands$ by the time everyone in our business with an interest in that part is properly aware of the change and the changes are carved into the stone of what has been euphemistically called "configuration management." I've had conversations with my contemporaries at RAC about what goes on in the OBAM aviation community and nearly to a man, they all look wistful and say, "Gee . . . I wish we could do that out here." If any of us could make a living in OBAM aircraft, we'd all be working for somebody else but the BePipCesMo crowd. Alas, that same over-regulated, exclusively marketed line of products is still producing a huge cash flow. As long as that river of cash is sufficient for each of us to get a tiny hook into it and snag off enough for a living, we'll hang around. There are still some fun days. Took a Saturday morning today to put my data acquisition system on a Beechjet and track down a malfunction in a tail deice system. This problem has plagued my boss and the airplane's owners for months. They've already spent a bucket of money on the usual but inadequate isolation techniques. There are few things that will bring me out to the airport on Saturday morning (or in an ice storm) and this was one of them. It was a GREAT day. In the mean time, let's be mindful of what's gone before us both for the rich history of experience and as environments for learning. We are all graduating from "Certified U" and striking out on our own. Some of us will found new institutions. Some will be successful, others will not. But our mission here on the List should not be to judge ACTIONS of either OBAMdom or SPAMdom but to glean the simple-ideas from both that will provide foundation for building beyond where we are today in EITHER venue. The fact that a BE36 currently has a 14 or 28v system is irrelevant. What is relevant are the tradeoffs for the two systems in the ways we intend to apply them in an RV or Glasair and the selection of "tinker-toys" available to us for implementation of what ever decision is made. I'd love to take a stripped-out BE-36 and do a clean-slate systems installation. I'm sure we could take out lots of weight, add lots of value and maybe even pump some new market life into that venerable ol' beast . . . but some nicely built RV will still outrun it. BTW, it would still have a 28v, 100A and 20A alternators on it. Too much need for electric heat. Bob . . . ________________________________________________________________________________
From: "Guy and Jill Foreman" <guyjill01(at)hotmail.com>
Subject: elec smoke smell
Date: Sep 10, 2005
I turned on my split batt/alt switch, and heard a rapid clicking noise, followed by a elec smoke smell. I turned of the batt switch, and the smell went away. I decided to replace the batt relay, but never did find out where the smell was coming from. I know something got hot, but cant find where it came from. Any suggestions? ________________________________________________________________________________
From: "brian bollaert" <bbollaert(at)comcast.net>
Subject: Re: RV 10 wiring architecture
Date: Sep 10, 2005
Dave: You need to sign up to with the rv10-list(at)matronics.com E-mail Address(es): rv10-list(at)matronics.com this group will help you with such ?? as these . Brian Bollaert rv-10 builder #40200 ----- Original Message ----- From: "Dave & Brenda Emond" <d_emond(at)mweb.co.za> Subject: AeroElectric-List: Re: RV 10 wiring architecture > > > I am a non electric guy, starting out from scratch. I was hoping to get > answers and opinions on the following questions. > > How are Cessna, Mooney, Pipers ect wired up. Are they dual battery and dual > alternator? > > I want to keep my RV10 practical, and careful not to overdo the redundancy > part, keep it simple. > > I will in all probability end up with an electric panel, no vacuum. I like > the Grand Rapids system, Chelton is a bit too far away in $$$ terms. I would > probably back up with a Dynon, with an internal Nicad. I will be running > LASAR magneto's. My first thoughts are single Alternator and single battery? > > All suggestions and points of view are appreciated. > > Dave Emond > > > -- > > ________________________________________________________________________________
Date: Sep 10, 2005
From: Richard Riley <richard(at)RILEY.NET>
Subject: Re: elec smoke smell
Others will, I'm sure, have better suggestions. But I'd start off with have a halon extinguisher handy. At 05:15 PM 9/10/05, Guy and Jill Foreman wrote: > > >I turned on my split batt/alt switch, and heard a rapid clicking noise, >followed by a elec smoke smell. I turned of the batt switch, and the smell >went away. I decided to replace the batt relay, but never did find out where >the smell was coming from. I know something got hot, but cant find where it >came from. Any suggestions? > > >-- -- ________________________________________________________________________________
From: Kevin Horton <khorton01(at)rogers.com>
Subject: Re: RV 10 wiring architecture
Date: Sep 10, 2005
On 10 Sep 2005, at 16:01, Dave & Brenda Emond wrote: > > > > I am a non electric guy, starting out from scratch. I was hoping to > get > answers and opinions on the following questions. > > How are Cessna, Mooney, Pipers ect wired up. Are they dual battery > and dual > alternator? > > I want to keep my RV10 practical, and careful not to overdo the > redundancy > part, keep it simple. > > I will in all probability end up with an electric panel, no vacuum. > I like > the Grand Rapids system, Chelton is a bit too far away in $$$ > terms. I would > probably back up with a Dynon, with an internal Nicad. I will be > running > LASAR magneto's. My first thoughts are single Alternator and single > battery? > > All suggestions and points of view are appreciated. > How will you use the aircraft? VFR only? VFR and IFR? Day only? Day and night? Given how you will use the aircraft, and the electrically powered equipment, what are the consequences of a complete electrical failure? If you will be able to get the aircraft on the ground with an acceptable workload following a complete electrical failure, then you don't need to spend extra time/money/weight/maintenance cost on additional alternators and batteries. If you plan to do cross country flying, do you want the ability to get back home following an alternator or battery failure? Or, are you prepared to replace the alternator or battery while on the road? Kevin Horton RV-8 (finishing kit) Ottawa, Canada http://www.kilohotel.com/rv8 ________________________________________________________________________________
From: N1deltawhiskey(at)aol.com
Date: Sep 11, 2005
Subject: LVW problem
Bob, I have your AEC9005-101 LVW. I am not using the battery management feature, so have just connected the fused positive and ground wires along with the LED wires to the unit. I have not seen this unit work as expected. I verified continuity of the positive and ground wiring connections (overlooked checking the LED connections to be sure they were right today), but found no apparent issues with the wiring. I thought I would try something else, connection the positive and ground directly to a battery. It still did not work, but shortly thereafter I smelled hot insulation. I touched the wires leading to the LVM and didn't bother to hang on - just disconnected the battery real quick. Any idea of what the problem might be? How can I get this working properly? Could incorrectly wired LED wires cause this problem? (I will check those next time at the hanger.) Is it a defective unit? Regards, Doug Windhorn ________________________________________________________________________________
Date: Sep 11, 2005
From: rv-9a-online <rv-9a-online(at)telus.net>
Subject: LED annunciator lamps
A few months ago, several list browsers were discussing sources for LED annuciator lamps. I did a lot of research, and I wasn't happy with what was commercially available so I designed a family of lamp panels, available now through Vx Aviation http://www3.telus.net/aviation/vx.html Also, the free aircraft electrical system schematic on the site has been updated. Dynon contacted me with a warning not to use the switched power output from the D10A as an emergency power source for the E-MAG/P-MAG ignition. The design has been updated to reflect this change. Thanks, Vern Little RV-9A ________________________________________________________________________________
From: <bbradburry(at)allvantage.com>
Subject: Parts to build the OV protector
Date: Sep 11, 2005
I was going to try and build the OV crowbar module as suggested by Bob. I discovered that the MBS4991 is an invalid part number with Digikey and they only have two of the other parts in stock. With a $5 handling charge, I need to get the complete order if possible. Can someone tell me part numbers and sources for these parts? I am not an electrician, so I don't even know what the part that they don't have is, since I don't understand the symbol in the drawing. The resistors I suppose I could get at Radio Shack, maybe the diode and the potentiometer? Thanks, Bill Bradburry ________________________________________________________________________________
Date: Sep 11, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Parts to build the OV protector
> >I was going to try and build the OV crowbar module as suggested by Bob. I >discovered that the MBS4991 is an invalid part number with Digikey and they >only have two of the other parts in stock. With a $5 handling charge, I >need to get the complete order if possible. > >Can someone tell me part numbers and sources for these parts? I am not an >electrician, so I don't even know what the part that they don't have is, >since I don't understand the symbol in the drawing. > >The resistors I suppose I could get at Radio Shack, maybe the diode and the >potentiometer? Your looking at a very old version which utilized a part now obsolete. The latest version will be published later today or tomorrow. I've updated the schematics and BOM and thought I'd got them posted but an astute reader pointed out the error of that impression a couple of days ago. I'll try to get caught up this evening. Bob . . . ________________________________________________________________________________
Date: Sep 11, 2005
From: "Dave Morris \"BigD\"" <BigD(at)DaveMorris.com>
Subject: Re: LED annunciator lamps
That's very cool! But, as I was designing my annunciator system, I found a need for not only active high and active low, but also a threshold type trigger where you can set a voltage comparator to trigger at a certain voltage level. That would allow you to build both LV and HV annunciators for the bus, as well as monitoring a number of other sensors without a lot of external circuitry, for example carb ice, fuel tank level, AOA sensor, and so on. Regards, Dave Morris At 09:29 AM 9/11/2005, you wrote: > >A few months ago, several list browsers were discussing sources for LED >annuciator lamps. > >I did a lot of research, and I wasn't happy with what was commercially >available so I designed a family of lamp panels, available now through >Vx Aviation http://www3.telus.net/aviation/vx.html > >Also, the free aircraft electrical system schematic on the site has been >updated. Dynon contacted me with a warning not to use the switched >power output from the D10A as an emergency power source for the >E-MAG/P-MAG ignition. The design has been updated to reflect this change. > >Thanks, > >Vern Little >RV-9A > > ________________________________________________________________________________
Date: Sep 11, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: LVW problem
> >Bob, > >I have your AEC9005-101 LVW. I am not using the battery management feature, >so have just connected the fused positive and ground wires along with the LED >wires to the unit. > >I have not seen this unit work as expected. I verified continuity of the >positive and ground wiring connections (overlooked checking the LED >connections >to be sure they were right today), but found no apparent issues with the >wiring. > >I thought I would try something else, connection the positive and ground >directly to a battery. It still did not work, but shortly thereafter I >smelled hot >insulation. I touched the wires leading to the LVM and didn't bother to hang >on - just disconnected the battery real quick. > >Any idea of what the problem might be? How can I get this working properly? >Could incorrectly wired LED wires cause this problem? (I will check those >next >time at the hanger.) Is it a defective unit? I've never had one returned. They're easy to check. Get a 9-pin d-sub female connector from Radio Shack or other handy source. Short pins 2 and 3 together. Put leadwires on pins 4 (+in) and 6 (ground). Plug your LVW/ABMM module into this connector and then connect the pin 4 wire to (+) on your car battery and pin 6 wire to (-) or ground. Engine should not be running for this test. If the module is okay, it the LED on the module will be flashing. Start the engine and repeat the test. The LED should not be flashing. Bob . . . ________________________________________________________________________________
From: "Rodney Dunham" <rdunhamtn(at)hotmail.com>
Subject: Parts to build the OV protector
Date: Sep 11, 2005
Brad, Why would you even consider building you own OV crowbar module??? B&C Specialties has one for just $35! I installed one in my OBAM and glad I did. No creative electrical engineering for me. Rodney >From: <bbradburry(at)allvantage.com> >Reply-To: aeroelectric-list(at)matronics.com >To: >Subject: AeroElectric-List: Parts to build the OV protector >Date: Sun, 11 Sep 2005 10:43:07 -0400 > > >I was going to try and build the OV crowbar module as suggested by Bob. I >discovered that the MBS4991 is an invalid part number with Digikey and they >only have two of the other parts in stock. With a $5 handling charge, I >need to get the complete order if possible. > >Can someone tell me part numbers and sources for these parts? I am not an >electrician, so I don't even know what the part that they don't have is, >since I don't understand the symbol in the drawing. > >The resistors I suppose I could get at Radio Shack, maybe the diode and the >potentiometer? > >Thanks, >Bill Bradburry > > ________________________________________________________________________________
Date: Sep 11, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: elec smoke smell
> >Others will, I'm sure, have better suggestions. But I'd start off >with have a halon extinguisher handy. > > >At 05:15 PM 9/10/05, Guy and Jill Foreman wrote: > > > > > > >I turned on my split batt/alt switch, and heard a rapid clicking noise, > >followed by a elec smoke smell. I turned of the batt switch, and the smell > >went away. I decided to replace the batt relay, but never did find out where > >the smell was coming from. I know something got hot, but cant find where it > >came from. Any suggestions? Pull all fuses/breakers. Install a temporary fuse in series with your battery. I recommend a MAX30 and HHX inline holder like the one on page 12 of http://www.bussmann.com/shared/library/catalogs/Buss_Auto-Fuse_Cat.pdf You can find these at many car parts stores. Power system up battery only. Push breakers in/install fuses in one system at a time and test each one for functionality. When a system has been checked, pull that fuse/breaker back out. If you can't locate a "dead" system, then hook some kind of visual or audible indicator to the downstream side of your MAX30 and start pushing and pulling on things. You're looking for something loose and/or cut wherein the original fault cleared when you smelled smoke the first time. You're trying to get it to repeat but without smoke this time. Bob . . . ________________________________________________________________________________
Date: Sep 11, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: RV 10 wiring architecture
>----- Original Message ----- >From: "Dave & Brenda Emond" <d_emond(at)mweb.co.za> >To: >Subject: AeroElectric-List: Re: RV 10 wiring architecture > > > > > > > > > I am a non electric guy, starting out from scratch. I was hoping to get > > answers and opinions on the following questions. > > > > How are Cessna, Mooney, Pipers ect wired up. Are they dual battery and > > dual alternator? > > > > I want to keep my RV10 practical, and careful not to overdo the redundancy > > part, keep it simple. > > > > I will in all probability end up with an electric panel, no vacuum. I like > > the Grand Rapids system, Chelton is a bit too far away in $$$ terms. I > would > > probably back up with a Dynon, with an internal Nicad. I will be running > > LASAR magneto's. My first thoughts are single Alternator and single > battery? > > > > All suggestions and points of view are appreciated. Dave, Sounds like you're pretty far down on the learning curve. Tell us a bit about yourself and your building environment. Are you familiar with the other RV-Lists on Matronics? Are there some builders in your area who are also working on an RV? Are you a member of your local EAA chapter? How far along are you on your project? I'll suggest you consider purchasing a copy of The AeroElectric Connection which is described at http://aeroelectric.com/Catalog/pub/pub.html and can be ordered from a number of dealers including Wicks, Steinair, B&C, buildersbooks, and from our website at: http://aeroelectric.com/Catalog/AECcatalog.html Start with chapter 17 which speaks to system reliability and system tailoring to the builder's mission and capabilities of the airplane. If "going stock" with a clone of systems found on certified ships is of interest, you can get real close with a minimum of effort/risk by installing the system recommended by Van's. If you want something different, then Chapter 17 is a good place to start. Without knowing more than you've told us so far, it's difficult to advise now but consider a Figure Z-11 architecture (See: http://aeroelectric.com/articles/Rev11/AppZ_R11C.pdf with an eye of upgrading to Figure Z-13/8 later. Are you hard over on the LASAR system? You can do as well for a lot less money, installation time, weight and probably better reliability with owner build and maintained (OBAM) aircraft alternatives. Lightspeed has a track record of over 15 years in the industry. E-Mag (emagair.com) are the up-and-commers who show a great deal of promise. What ever you do, put of buying any major electronics, or even batteries until as late in your project as possible. Welcome to the AeroElectric-List. Help us out by telling us more about how you want to use this airplane. Bob . . . ________________________________________________________________________________
Date: Sep 11, 2005
From: Charlie England <ceengland(at)bellsouth.net>
Subject: Re: Use a 28vdc alternator in 14vdc system?
Robert L. Nuckolls, III system? wrote: > > > > >> >> >> >> >>>From: "Bruce Gray" <Bruce(at)glasair.org> >>>Date: 2005/09/08 Thu PM 09:56:40 CDT >>>To: >>>Subject: RE: AeroElectric-List: Use a 28vdc alternator in 14vdc system? >>> >>> >>>How many 14v airplanes does RAC or Cessna make today? Zip..Nada..Zero >>> >>>Bruce >>>www.glasair.org >>> >>> >>Do you fly a Cessna or RAC a/c? Why is their opinion better for electrical >>systems if it's not better for a/c selection? ;-> >> >> > > Gently Charlie, we know the BePipCesMo guys are hard pressed > just to stay in business under the worst of economic and working > conditions; making detailed evolutionary refinements in on-board systems > is simply impossible. Virtually EVERY decision for making changes > has to be made under the albatross of, "what will it cost us to get > dispensation and blessings from the East?" I'm told the cost > of implementing a change to one sheet of paper describing a part > of our products can cost 5 to 7 $thousands$ by the time everyone > in our business with an interest in that part is properly aware > of the change and the changes are carved into the stone of what > has been euphemistically called "configuration management." > > I've had conversations with my contemporaries at RAC about what > goes on in the OBAM aviation community and nearly to a man, > they all look wistful and say, "Gee . . . I wish we could > do that out here." If any of us could make a living in OBAM > aircraft, we'd all be working for somebody else but the BePipCesMo > crowd. Alas, that same over-regulated, exclusively marketed line > of products is still producing a huge cash flow. As long as > that river of cash is sufficient for each of us to get a tiny > hook into it and snag off enough for a living, we'll hang around. > > There are still some fun days. Took a Saturday morning today to > put my data acquisition system on a Beechjet and track down > a malfunction in a tail deice system. This problem has plagued > my boss and the airplane's owners for months. They've already > spent a bucket of money on the usual but inadequate isolation > techniques. There are few things that will bring me out to > the airport on Saturday morning (or in an ice storm) and this > was one of them. It was a GREAT day. > > In the mean time, let's be mindful of what's gone before us > both for the rich history of experience and as environments > for learning. We are all graduating from "Certified U" and striking > out on our own. Some of us will found new institutions. Some > will be successful, others will not. But our mission here on the > List should not be to judge ACTIONS of either OBAMdom or SPAMdom > but to glean the simple-ideas from both that will provide > foundation for building beyond where we are today in EITHER > venue. The fact that a BE36 currently has a 14 or 28v system is > irrelevant. What is relevant are the tradeoffs for the two > systems in the ways we intend to apply them in an RV or > Glasair and the selection of "tinker-toys" available > to us for implementation of what ever decision is made. > > I'd love to take a stripped-out BE-36 and do a clean-slate > systems installation. I'm sure we could take out lots of weight, > add lots of value and maybe even pump some new market life > into that venerable ol' beast . . . but some nicely built > RV will still outrun it. BTW, it would still have a 28v, 100A > and 20A alternators on it. Too much need for electric heat. > > Bob . . . > Sorry; that was intended to be a little good natured kidding & must have been a bit too...concise. My thought was very similar to yours: the factory decision making is driven by many factors that we don't have to consider & we have the freedom to do what's best for our a/c, not driven by big business/certification issues. For example, I don't use a certified battery, or certified air/oil separator, etc, etc in my RV-4, even though all the factory guys have to. If the original poster's *only* criteria for designing an electrical system is 'What would RAC/Cessna do?' then it can logically follow that RAC/Cessna can also answer the question, 'What airplane should I fly?' for him. Charlie ________________________________________________________________________________
Date: Sep 11, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Parts to build the OV protector
> > > > > > >I was going to try and build the OV crowbar module as suggested by Bob. I > >discovered that the MBS4991 is an invalid part number with Digikey and they > >only have two of the other parts in stock. With a $5 handling charge, I > >need to get the complete order if possible. > > > >Can someone tell me part numbers and sources for these parts? I am not an > >electrician, so I don't even know what the part that they don't have is, > >since I don't understand the symbol in the drawing. > > > >The resistors I suppose I could get at Radio Shack, maybe the diode and the > >potentiometer? > > Your looking at a very old version which utilized a part > now obsolete. The latest version will be published later > today or tomorrow. I've updated the schematics and BOM > and thought I'd got them posted but an astute reader > pointed out the error of that impression a couple of > days ago. I'll try to get caught up this evening. Done. Download . . . http://aeroelectric.com/articles/Crowbar_OV_Protection/Crowbar_C.pdf Bob . . . ________________________________________________________________________________
Date: Sep 11, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Crowbar OVM schematic version?
D, Thanks for "picking the nits" . . . I thought I'd updated that page. See: http://aeroelectric.com/articles/Crowbar_OV_Protection/Crowbar_C.pdf Bob . . . > >Howdy Bob - > >FYI (from a nitpickin' proof reader) - it seems that an older schematic >and BOM snuck back onto page 1 of the Crowbar OVM document (02/20/01): > >http://aeroelectric.com/articles/crowbar.pdf > >I dug out a schematic from 06/29/04, but I figured there might be an >even later revision to reflect Ken's contribution. No? > >Thanks, > >D > > >-- > > >-- incoming mail is certified Virus Free. Bob . . . -------------------------------------------------------- < Throughout history, poverty is the normal condition > < of man. Advances which permit this norm to be > < exceeded -- here and there, now and then -- are the > < work of an extremely small minority, frequently > < despised, often condemned, and almost always opposed > < by all right-thinking people. Whenever this tiny > < minority is kept from creating, or (as sometimes > < happens) is driven out of a society, the people > < then slip back into abject poverty. > < > < This is known as "bad luck". > < -Lazarus Long- > <------------------------------------------------------> http://www.aeroelectric.com ________________________________________________________________________________
Date: Sep 12, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Use a 28vdc alternator in 14vdc system?
>Sorry; that was intended to be a little good natured kidding & must have >been a bit too...concise. My thought was very similar to yours: the >factory decision making is driven by many factors that we don't have to >consider & we have the freedom to do what's best for our a/c, not driven >by big business/certification issues. For example, I don't use a >certified battery, or certified air/oil separator, etc, etc in my RV-4, >even though all the factory guys have to. > >If the original poster's *only* criteria for designing an electrical >system is 'What would RAC/Cessna do?' then it can logically follow that >RAC/Cessna can also answer the question, 'What airplane should I fly?' >for him. No big deal. There's always a risk with "one liners" that the spirit and intent can be left open to supposition and at least half the readers will get it wrong! I wasn't real sure . . . it would have helped me to consider the icon at the end . . . being an engineer tasked with communication by precise speech, I miss those things from time to time. Thank you for the follow up! Bob . . . ________________________________________________________________________________
Date: Sep 12, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Crowbar CB "problem" question
> > > AeroElectric-List message previously posted by: Richard Riley > > > > > > < > particularly one of the B&C regulators - how often do the nuisance > > trips occur? > > > > If we're worried about the nuisance trips degrading field CB's, would > > it be a reasonable fix to replace those CBs at annual?>> There are rumors suggesting that some breakers are severely overtaxed by the crowbar event that forces them open when using this particular technology for ov protection. I have researched this allegation extensively. I've produced many documents to combine with my personal anecdotal experience going back 25 years that will not support the allegation for the types of circuit breakers commonly used in the Spam Can and OBAM aircraft industries. The field breaker on B&C's regulator test stand got replaced after about ten years of testing running over 1000 regulators that were deliberately tripped as part of the acceptance test procedure. I can find no substantive concerns about breaker life in this application. Real problems have been rare and addressed as soon as individuals experiencing problems brought it to our attention. If the rate of problem events with components and systems on bizjets were as low as for the crowbar system, I'd be out of a job. Bob . . . ________________________________________________________________________________
From: "Guy and Jill Foreman" <guyjill01(at)hotmail.com>
Subject: Re: elec smoke smell
Date: Sep 12, 2005
Thanks for the advise. I'll try this today. thanks, guy >From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> >Reply-To: aeroelectric-list(at)matronics.com >To: aeroelectric-list(at)matronics.com >Subject: Re: AeroElectric-List: elec smoke smell >Date: Sun, 11 Sep 2005 21:41:32 -0500 > > > > > > > > >Others will, I'm sure, have better suggestions. But I'd start off > >with have a halon extinguisher handy. > > > > > >At 05:15 PM 9/10/05, Guy and Jill Foreman wrote: > > > > > > > > > > >I turned on my split batt/alt switch, and heard a rapid clicking noise, > > >followed by a elec smoke smell. I turned of the batt switch, and the >smell > > >went away. I decided to replace the batt relay, but never did find out >where > > >the smell was coming from. I know something got hot, but cant find >where it > > >came from. Any suggestions? > > Pull all fuses/breakers. Install a temporary fuse in > series with your battery. I recommend a MAX30 and HHX inline holder > like the one on page 12 of > >http://www.bussmann.com/shared/library/catalogs/Buss_Auto-Fuse_Cat.pdf > > You can find these at many car parts stores. > > Power system up battery only. Push breakers in/install fuses in one > system at a time and test each one for functionality. When a system > has been checked, pull that fuse/breaker back out. If you can't locate > a "dead" system, then hook some kind of visual or audible indicator > to the downstream side of your MAX30 and start pushing and pulling > on things. You're looking for something loose and/or cut wherein > the original fault cleared when you smelled smoke the first time. > You're trying to get it to repeat but without smoke this time. > > Bob . . . > > ________________________________________________________________________________
Date: Sep 12, 2005
From: rv-9a-online <rv-9a-online(at)telus.net>
Subject: Re: LED annunciator lamps
Dave, you must have had fun building your annunciator system. It would be interesting to get more details. These kind of alarm functions are also contained in even simple engine monitors, such as the Rocky Mountain or Grand Rapids devices. These devices usually have a master alarm output (visual and/or audible) that you can tie to a single Lamp, labelled 'ENGINE' or something similar. This lamp would then call your attention to the engine monitor which should be displaying the out-of-limit field. On my aircraft, I or-tie the engine monitor alarm output with a low oil pressure switch. This 'master' alarm serves three primary functions: Alarms from the engine monitor; fail-safe low oil pressure alarm (engine monitor not operating), and a master switch 'on' alarm. Vern Little RV-9A Dave Morris "BigD" wrote: > >That's very cool! But, as I was designing my annunciator system, I found a >need for not only active high and active low, but also a threshold type >trigger where you can set a voltage comparator to trigger at a certain >voltage level. That would allow you to build both LV and HV annunciators >for the bus, as well as monitoring a number of other sensors without a lot >of external circuitry, for example carb ice, fuel tank level, AOA sensor, >and so on. > >Regards, > >Dave Morris > > >At 09:29 AM 9/11/2005, you wrote: > > >> >>A few months ago, several list browsers were discussing sources for LED >>annuciator lamps. >> >>I did a lot of research, and I wasn't happy with what was commercially >>available so I designed a family of lamp panels, available now through >>Vx Aviation http://www3.telus.net/aviation/vx.html >> >>Also, the free aircraft electrical system schematic on the site has been >>updated. Dynon contacted me with a warning not to use the switched >>power output from the D10A as an emergency power source for the >>E-MAG/P-MAG ignition. The design has been updated to reflect this change. >> >>Thanks, >> >>Vern Little >>RV-9A >> >> >> >> > > > > ________________________________________________________________________________
Date: Sep 12, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Parts to build the OV protector
> > >Brad, > >Why would you even consider building you own OV crowbar module??? > >B&C Specialties has one for just $35! > >I installed one in my OBAM and glad I did. No creative electrical >engineering for me. > >Rodney It depends on your goals. It's true that one can almost never assemble a product from scratch for less than it costs assembled. But one learns nothing about the processes, techniques and materials until you put your hands on them. Education is ALWAYS expensive in terms of time . . . and when purchasing parts for one instead off 100, they're more expensive too. The difference is that the folks who have done it are (by their own choice) more of a subject matter expert than those who have not. That's the major difference between myself and most of my contemporaries in the certified aviation industry. I've made it a career goal to put my hands on lots of different technologies, techniques and materials. It's been expensive but fun and it's now producing a return on investment. Bob . . . ________________________________________________________________________________
Date: Sep 12, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Noise Filter for 5 lead motor
> >Yes, I have run this fan motor, but only from the battery (engine not >running): > >Low, medium, and high fan speeds work just fine, but when switching past >low,the supercharger high manifold pressure light comes on and stays on.To >get it off, I have to pull the 9pin dsub off the supercharger controller. >Once reconnected,as soon as I start moving that heater switch past the low >position, on comes thelight.My supercharger controller power is taken from >the line side of abreaker comingfrom the Auxbattery, while the heater >power is coming off the other side (the load side)of the same breaker. > >I've since removed the fan power and its 3 speed control wires well >away from the supercharger controller wires, as well as moved the >fan power source off the breaker near the supercharger controller source, >but I get the same response. > >Does this mean it's RFI coming from the fan motor (the motor case is plastic, >not metal)? > >And is this a candidate for an inductor/capacitor filter near the motor? My friend, you're now confronted with the classic chicken/egg conundrum in electromagnetic compatibility issues. (1) is the supercharger controller SPECIFIED to operate in any defined/known levels of abnormal stimulus? It appears to be an extraordinarily susceptible system. The fact that it wanders off into the weeds and locks up is particularly significant. If it just hiccupped and then went on about its business, we could feel more comfortable with a simple mitigation of stimulus by filtering at the antagonist, breaking propagation mode(s) or mitigation by filtering at the victim. My sense is that even if you FIXED the present problem with the fan, the system seems likely to be a high-risk victim for other noise sources. Given that your engine operation depends on reliable function of this product, I think it would be a good idea to have some discussion with the manufacturer. Do you have a wiring diagram for the controller you could scan and send to me? I think my initial approach to the problem would be to add protection AT the victim. Bob . . . ________________________________________________________________________________
Subject: Bringing alternator on line after engine start.
Date: Sep 12, 2005
From: "Rogers, Bob J." <BRogers(at)fdic.gov>
I am building a Mustang II kit plane with a Mazda Rotary 13B engine for power. The stock alternator is a 60 amp internally regulated Mitsubishi, which will be my primary source of electrical power. In addition to the stock alternator, I also have a John Deere 35 amp permanent magnet (PM) alternator for a backup. The electrical system is designed to receive power from either alternator, but not both at the same time. I want to be able to check that both alternators are working before take-off, which requires that I switch the electrical feed from one alternator to the other while the engine is running. The switch would be through a contactor for each alternator, which connects/disconnects the B terminal, as well as the electrical feed to the L & R terminals (which activate the alternator). I have followed the past discussions about how it is not a good idea to take an internally regulated alternator off-line after it is producing electricity. But, my Mazda service manual has a warning that I should not start the engine with the L & R terminals disconnected (these are the terminals that are used to activate the alternator). My plan was to start the engine with the backup PM alternator activated, check that it was working, and then switch to the main 60 amp alternator and leave it on. I would not go back to the PM alternator unless my primary alternator failed. My confusion is with the warning in the service manual that I should not start the engine unless the (main) alternator is already on line. I do not know the purpose for the warning and I do not comprehend the possible consequences of waiting to bring the primary alternator on line. If I start the engine with the back-up PM alternator on line and later switch to the primary (stock) alternator, which is my plan, I will be violating the warning in the service manual, because until I switch to the main alternator after the engine is running, the L & R terminals for the main alternator will, in effect, be disconnected. Can Bob Nuckolls or anyone else give me some advice on the correct procedure and sequence for checking that each alternator is functioning prior to take-off, without doing any harm to my electrical system? Also, I would like to hear your speculation on why the Mazda service manual has the warning discussed above. ________________________________________________________________________________
From: revenson(at)comcast.net
Subject: Re: Noise Filter for 4 lead motor
Date: Sep 12, 2005
(By the way, I characterized this wrong initially--there are 4 leads coming from the fan, not 5---ground, high, medium, and low speed). Here are my results so far: Battery condition was fine. Ground wire integrity was fine. Fan motor wires were rerouted. Problem still existed. Moved fan wires a foot or so away from the plane. Still light came on. Was able to fix it at the 'victim' two ways: Took the controller box off the aluminum subpanel where it was grounded locally with its mounting screws (in addition to the controller's ground wire). Just holding it up (insulating it from the airframe) resulted in no more light. So perhaps this was a ground loop issue. Secondly, I was in Radio Shack and happened to see part #273-105, a snap-on Ferrite Data-Line Filter ($5). This clamped nicely over the controller wires right at the dsub connector. This also independently solved the effects of the problem. I don't have a wiring diagram, but the supercharger manufacturer has been great. He's sending me a new chip that will eliminate the 'lock on' of the light. It will still be susceptible to voltage fluctuations, but at least it will reset and return to service. Still want to fix the antagonist. Took the fan motor out of the plane and my EAA tech counselor hooked it to an oscilloscope. It was quite noisy--the spikes were approx. 4-5 volts. These spikes didn't show up with a voltmeter. Placing a .01 micro farad ceramic, non-polarized capacitor across the main motor lead (hi speed) and the ground right at the motor showed very substantial noise reduction. Spikes went from several volts to 100-200 micro volts. Have not yet reinstalled the motor to verify, but I'm pretty sure this will fix this problem, and hopefully prevent other potential noise problems from this source. Roger. > > My friend, you're now confronted with the classic chicken/egg > conundrum in electromagnetic compatibility issues. > > (1) is the supercharger controller SPECIFIED to operate in > any defined/known levels of abnormal stimulus? It appears > to be an extraordinarily susceptible system. The fact that > it wanders off into the weeds and locks up is particularly > significant. If it just hiccupped and then went on about its > business, we could feel more comfortable with a simple mitigation > of stimulus by filtering at the antagonist, breaking propagation > mode(s) or mitigation by filtering at the victim. > > My sense is that even if you FIXED the present problem with > the fan, the system seems likely to be a high-risk victim > for other noise sources. Given that your engine operation > depends on reliable function of this product, I think it > would be a good idea to have some discussion with the > manufacturer. Do you have a wiring diagram for the controller > you could scan and send to me? I think my initial approach > to the problem would be to add protection AT the victim. > > Bob . . . > (By the way, I characterized this wrong initially--there are 4 leads coming from the fan, not 5---ground, high, medium, and low speed). Here are my resultsso far: Battery condition was fine. Ground wire integrity was fine. Fan motor wires were rerouted.Problem still existed. Moved fan wires a foot or so away from the plane. Still light came on. Was able to fix it at the 'victim' two ways: Took thecontroller box off thealuminum subpanel where it was grounded locally with its mounting screws (in addition to the controller's ground wire).Just holding it up (insulating it from the airframe)resulted in no more light. So perhaps this was a ground loop issue. Secondly, I was in Radio Shack and happened to see part #273-105, a snap-on Ferrite Data-Line Filter ($5). This clamped nicely over the controller wires right at the dsub connector. This also independently solved the effects of the problem. I don't have a wiring diagram, butthe supercharger manufacturer has been great.He's sending me a new chip that will eliminate the 'lock on' of the light.It will still be susceptible to voltage fluctuations, but at least it will reset and return to service. Still want to fixthe antagonist.Took the fan motorout of the plane and my EAA tech counselorhooked it to an oscilloscope. It was quite noisy--the spikes were approx. 4-5 volts. These spikes didn't show up with a voltmeter. Placing a .01 micro farad ceramic, non-polarized capacitor across the main motor lead (hi speed) and the ground right at the motor showed very substantial noise reduction. Spikes went from several volts to 100-200 micro volts. Have notyetreinstalled the motor to verify, but I'm pretty sure this will fix thisproblem, andhopefully preventother potentialnoise problems fromthissource. Roger. My friend, you're now confronted with the classic chicken/egg conundrum in electromagnetic compatibility issues. (1) is the supercharger controller SPECIFIED to operate in any defined/known levels of abnormal stimulus? It appears to be an extraordinarily susceptible system. The fact that it wanders off into the weeds and locks up is particularly significant. If it just hiccupped and then went on about its business, we could feel more comfortable with a simple mitigation of stimulus by filtering at the antagonist, breaking propagation mode(s) or mitigation by filtering at the victim. My sense is that even if you FIXED the present problem with the fan, the system seems likely to be a high-risk victim for other noise sources. Given that your engine operation depends on reliable function of this product, I think it woul d be a good idea to have some discussion with the manufacturer. Do you have a wiring diagram for the controller you could scan and send to me? I think my initial approach to the problem would be to add protection AT the victim. Bob . . . ________________________________________________________________________________
From: "Dave & Brenda Emond" <d_emond(at)mweb.co.za>
Subject: Re: RV 10 wiring architecture
Date: Sep 12, 2005
Fellow members Thanks for the replies, I will attempt to elaborate further, and appreciate your points of view. I have gone the QB route. I have just started the Fuse and hence the realisation that I need to start giving wiring and avionics some serious thought. I belong to chapter 645 which is based in Durban, South Africa. There are a couple of RV's being built at present. I do follow the matronics lists, and appreciate the the openess and spirit in which topics are discussed and information shared. I visited Oshkosh this year and got to meet some RV owners and builders. I bought a copy of the AeroElectric Connection and learnt much from it. Remembering I started from scratch, not difficult to double what I know about electrics, did that in the first paragraph. lol I am not IFR rated, so would put a VFR panel in to start with, I would like to fly night VFR, and then as future funding allows start looking towards upgrading to an IFR panel, and getting IFR rated. Hence I would like to start considering how to best configure the wiring side of my RV10 to accomodate easy upgrade going forward. Mission of my RV10 will be cross country. The LASAR ignition appealed to me because I know of two other local aircraft, using it. It has been reliable, and gives me confidence that lack of electrical power, doesn't equal engine shut down. I will take Bobs advice and read chapter 17, hopefully 1battery or two batteries. 1 alternator or two alternators. Will become more apparant. Dave Emond RV 10 #40159 > > Start with chapter 17 which speaks to system reliability > and system tailoring to the builder's mission and capabilities > of the airplane. > > If "going stock" with a clone of systems found on certified > ships is of interest, you can get real close with a minimum > of effort/risk by installing the system recommended by Van's. > > If you want something different, then Chapter 17 is a good > place to start. Without knowing more than you've told us so > far, it's difficult to advise now but consider a Figure > Z-11 architecture (See: > > http://aeroelectric.com/articles/Rev11/AppZ_R11C.pdf > > with an eye of upgrading to Figure Z-13/8 later. > > Are you hard over on the LASAR system? You can do as > well for a lot less money, installation time, weight > and probably better reliability with owner build and > maintained (OBAM) aircraft alternatives. Lightspeed > has a track record of over 15 years in the industry. > E-Mag (emagair.com) are the up-and-commers who show > a great deal of promise. > > What ever you do, put of buying any major electronics, > or even batteries until as late in your project as > possible. > > Welcome to the AeroElectric-List. Help us out by > telling us more about how you want to use this airplane. > > > Bob . . . > > > ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: Crowbar CB "problem" question
Date: Sep 12, 2005
Bob, as one of the "rumor mongers" I think you may have misunderstood my comments (or my intent at least). I never stated that damage was certain (or even likely). My point was, and is, that manufacturers clearly state that operation outside specified ranges MAY result in operation that is out of specification (this means some damage MAY occur, or the trip time or trip current may change or even failure to trip at all, just burn open). This is listed in the manufacturers specification for the device. Its never a good design practice to design a circuit that allows out of specification operation, and in this case, its so simple to prevent with the simple addition of a commonly available resistor that has no noticeable effect on the intended purpose of the circuit and prevents out of specification operation. Its simply not reasonable to assume that any 5 amp CB can be used and never damaged. No specific make and model CB has been specified so its reasonable to assume that any CB with the proper rating can be used and some sold by Aircraft Spruce etc have documented maximum ratings much lower than the maximum potential current in this application. Many parts have the ability to withstand major overload with no apparent (or real) damage but assuming that as fact is never a good idea. Paul ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> Subject: Re: AeroElectric-List: Crowbar CB "problem" question > > > >> >> > AeroElectric-List message previously posted by: Richard Riley >> > >> > >> > <> > particularly one of the B&C regulators - how often do the nuisance >> > trips occur? >> > >> > If we're worried about the nuisance trips degrading field CB's, would >> > it be a reasonable fix to replace those CBs at annual?>> > > > There are rumors suggesting that some breakers are severely > overtaxed by the crowbar event that forces them open when > using this particular technology for ov protection. > > I have researched this allegation extensively. I've produced > many documents to combine with my personal anecdotal experience > going back 25 years that will not support the allegation > for the types of circuit breakers commonly used in the > Spam Can and OBAM aircraft industries. The field breaker > on B&C's regulator test stand got replaced after about > ten years of testing running over 1000 regulators that > were deliberately tripped as part of the acceptance test > procedure. > > I can find no substantive concerns about breaker life > in this application. Real problems have been rare and addressed > as soon as individuals experiencing problems brought it to > our attention. If the rate of problem events with components > and systems on bizjets were as low as for the crowbar system, > I'd be out of a job. > > Bob . . . > > > ________________________________________________________________________________
Date: Sep 12, 2005
From: <chaztuna(at)adelphia.net>
Subject: Inexpensive source for heat shrink tubing for Kroy,
KSun labers needed Listers, imagesupply.com offers heat shrink tubing kits for various labeling machines (I'm most interested in Kroy & KSun units) for $29. Anyone know of a less expensive source? Charlie Kuss ________________________________________________________________________________
Subject: Dumb question time
Date: Sep 12, 2005
From: "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com>
I have an electrically dependant airplane (Lycoming with electric fuel pumps only). I see from the Z figures that there is no fuseable link in the Batt buss feed from the battery, the wire is pretty thin and short 6" or less. In my case the feed wire will need to be about 1.5 feet and capable of supporting a load of about 16 amps max running. Considering the engine will make like a glider if this lead shorts to ground (it will be well protected!) what size of wire should I install and should I install an automotive fuse link...Working on the principle that a glider is better than a glider with a cockpit fire? Thanks Frank ________________________________________________________________________________
Date: Sep 12, 2005
From: Bob White <bob@bob-white.com>
KSun.labers.needed(at)roxy.matronics.com
Subject: Re: Inexpensive source for heat shrink tubing
for Kroy, KSun labers needed If you need any quantity at all, I would reccomend Merithan Products Corp. http://tinyurl.com/75qwx For example, They will make 500 1/8 in dia labels 1/2 inch long printed with whatever you want for $28.50. Thats less than the $29 cartridge and more than twice the length (250 in. vs 110 in.) It isn't clear from the web site, but they will let you print several different labels and still give you the quantity price break for the total. I'm not sure but you may have to order 500 each to avoid the setup fee. - And I didn't need to buy a $300 printer. use the 1/8 inch or larger shrink tubing if you can. They have a little trouble keeping the text aligned on the 3/32 stuff. Of course if you need the flexability of printing a few at a time, this won't help. Bob W. wrote: > > Listers, > imagesupply.com offers heat shrink tubing kits for various labeling machines (I'm most interested in Kroy & KSun units) for $29. Anyone know of a less expensive source? > Charlie Kuss > > > > > > > > -- http://www.bob-white.com N93BD - Rotary Powered BD-4 (real soon) Prewired EC2 Cables - http://www.roblinphoto.com/shop/ ________________________________________________________________________________
Date: Sep 12, 2005
From: Jim Streit <wooody04(at)bellsouth.net>
KSun.labers.needed(at)roxy.matronics.com
Subject: Re: Inexpensive source for heat shrink tubing
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Anyone know of a less expensive source? >Charlie Kuss > > > > ________________________________________________________________________________
Date: Sep 12, 2005
Subject: Re: Dumb question time
From: "Matt Prather" <mprather(at)spro.net>
What kind of fuel delivery system does your airplane use? Is it aircraft or automotive derivative? Regards, Matt- > (Corvallis)" > > I have an electrically dependant airplane (Lycoming with electric fuel > pumps only). > > I see from the Z figures that there is no fuseable link in the Batt buss > feed from the battery, the wire is pretty thin and short 6" or less. > > In my case the feed wire will need to be about 1.5 feet and capable of > supporting a load of about 16 amps max running. > > Considering the engine will make like a glider if this lead shorts to > ground (it will be well protected!) what size of wire should I install > and should I install an automotive fuse link...Working on the principle > that a glider is better than a glider with a cockpit fire? > > Thanks > > Frank > > ________________________________________________________________________________
From: "Bill and Marsha" <docyukon(at)ptcnet.net>
Subject: ARC R402A Marker Pin out
Date: Sep 12, 2005
Can any one supply me with a sys.pinout for a R402A Marker? Thanks Bill S. ________________________________________________________________________________
From: "William" <wschertz(at)ispwest.com>
Subject: PM alternator on Mazda engine.
Date: Sep 12, 2005
Bob, Where are you locating the PM alternator? Bill Schertz KIS Cruiser # 4045 Mazda 13-B ----- Original Message ----- From: "Rogers, Bob J." <BRogers(at)fdic.gov> Subject: AeroElectric-List: Bringing alternator on line after engine start. > > > I am building a Mustang II kit plane with a Mazda Rotary 13B engine for > power. The stock alternator is a 60 amp internally regulated > Mitsubishi, which will be my primary source of electrical power. In > addition to the stock alternator, I also have a John Deere 35 amp > permanent magnet (PM) alternator for a backup. ________________________________________________________________________________
From: Kevin Horton <khorton01(at)rogers.com>
Subject: Re: Crowbar CB "problem" question
Date: Sep 12, 2005
Paul, If you look at the whole aircraft industry worldwide, there are probably dozens (hundreds?) of events daily where CBs open due to overcurrent. I bet the vast majority of those CBs go back into service once the original problem is fixed. Yet, reports of problems caused by CBs that didn't open when should seem quite rare. Are you suggesting that CBs be considered one-time-use devices, to be replaced after any event that opens them, as we have no way of knowing what the current was? Under what conditions would you replace a CB, and under what conditions would you put it back in service? Kevin Horton On 12 Sep 2005, at 15:20, Paul Messinger wrote: > > > Bob, as one of the "rumor mongers" I think you may have > misunderstood my > comments (or my intent at least). > > I never stated that damage was certain (or even likely). > > My point was, and is, that manufacturers clearly state that operation > outside specified ranges MAY result in operation that is out of > specification (this means some damage MAY occur, or the trip time > or trip > current may change or even failure to trip at all, just burn open). > This is > listed in the manufacturers specification for the device. > > Its never a good design practice to design a circuit that allows > out of > specification operation, and in this case, its so simple to prevent > with the > simple addition of a commonly available resistor that has no > noticeable > effect on the intended purpose of the circuit and prevents out of > specification operation. > > Its simply not reasonable to assume that any 5 amp CB can be used > and never > damaged. > > No specific make and model CB has been specified so its reasonable > to assume > that any CB with the proper rating can be used and some sold by > Aircraft > Spruce etc have documented maximum ratings much lower than the maximum > potential current in this application. > > Many parts have the ability to withstand major overload with no > apparent (or > real) damage but assuming that as fact is never a good idea. > > Paul > > ----- Original Message ----- > From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> > To: > Subject: Re: AeroElectric-List: Crowbar CB "problem" question > > >> >> >> >> >>> >>> >>>> AeroElectric-List message previously posted by: Richard Riley >>>> >>>> >>>> <>>> particularly one of the B&C regulators - how often do the nuisance >>>> trips occur? >>>> >>>> If we're worried about the nuisance trips degrading field CB's, >>>> would >>>> it be a reasonable fix to replace those CBs at annual?>> >>>> >> >> >> There are rumors suggesting that some breakers are severely >> overtaxed by the crowbar event that forces them open when >> using this particular technology for ov protection. >> >> I have researched this allegation extensively. I've produced >> many documents to combine with my personal anecdotal experience >> going back 25 years that will not support the allegation >> for the types of circuit breakers commonly used in the >> Spam Can and OBAM aircraft industries. The field breaker >> on B&C's regulator test stand got replaced after about >> ten years of testing running over 1000 regulators that >> were deliberately tripped as part of the acceptance test >> procedure. >> >> I can find no substantive concerns about breaker life >> in this application. Real problems have been rare and addressed >> as soon as individuals experiencing problems brought it to >> our attention. If the rate of problem events with components >> and systems on bizjets were as low as for the crowbar system, >> I'd be out of a job. >> >> Bob . . . >> >> >> >> ________________________________________________________________________________
Date: Sep 12, 2005
From: D Wysong <hdwysong(at)gmail.com>
Subject: Re: Crowbar OVM schematic version?
Bob - Thanks for the crowbar BOM/schematic update. I wish you'd include a chapter in the 'connection that explains how you find/make/conjure up "free" time (... and without your wife finding out about it)?! Since someone brought up the buy vs. build topic, what flavor of OVM is B&C selling these days? Is there a way to guarantee we'll receive a Rev C unit if ordered tomorrow? The reason I ask is that the installation instructions on B&C's site contain a VERY outdated schematic. It doesn't affect the installation, of course, but it made me wonder how well they kept up with mod's. Thanks again for your service! D ________________________________________________________________________________
Date: Sep 12, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Crowbar OVM schematic version?
> >Bob - > >Thanks for the crowbar BOM/schematic update. I wish you'd include a chapter >in the 'connection that explains how you find/make/conjure up "free" time >(... and without your wife finding out about it)?! > >Since someone brought up the buy vs. build topic, what flavor of OVM is B&C >selling these days? Is there a way to guarantee we'll receive a Rev C unit >if ordered tomorrow? It's the ORIGINAL design with appropriate updates. B&C did a lifetime buy of the MBS4992 when it went obsolete. >The reason I ask is that the installation instructions on B&C's site contain >a VERY outdated schematic. It doesn't affect the installation, of course, >but it made me wonder how well they kept up with mod's. The original version doesn't need the added 22uf cap. The latest version has a very low gate pull-down resistor to offset dv/dt effects at the SCR anode. This configuration has been sold now for a couple of years and I'm not hearing any unhappy feedback from them. Bob . . . ________________________________________________________________________________
From: N1deltawhiskey(at)aol.com
Date: Sep 13, 2005
Subject: Re: LVW problem
Bob, Thanks. All of my wiring gear is at the hanger, so won't be doing this until next weekend. But in reading your response, I may have identified a/the problem. On the drawing I have, I interpreted the ground pin (-) as 5 rather than 6, and that is how I wired it. After looking more closely at the drawing, the 5's are different from the 6's - field of view (mentally) just wasn't broad enough. Think any damage was done with pin 5 grounded? I guess I will find out when I rewire and test it. Regards, Doug In a message dated 11-Sep-05 23:55:18 Pacific Standard Time, nuckollsr(at)cox.net writes: >Bob, > >I have your AEC9005-101 LVW. I am not using the battery management feature, >so have just connected the fused positive and ground wires along with the LED >wires to the unit. > >I have not seen this unit work as expected. I verified continuity of the >positive and ground wiring connections (overlooked checking the LED >connections >to be sure they were right today), but found no apparent issues with the >wiring. > >I thought I would try something else, connection the positive and ground >directly to a battery. It still did not work, but shortly thereafter I >smelled hot >insulation. I touched the wires leading to the LVM and didn't bother to hang >on - just disconnected the battery real quick. > >Any idea of what the problem might be? How can I get this working properly? >Could incorrectly wired LED wires cause this problem? (I will check those >next >time at the hanger.) Is it a defective unit? I've never had one returned. They're easy to check. Get a 9-pin d-sub female connector from Radio Shack or other handy source. Short pins 2 and 3 together. Put leadwires on pins 4 (+in) and 6 (ground). Plug your LVW/ABMM module into this connector and then connect the pin 4 wire to (+) on your car battery and pin 6 wire to (-) or ground. Engine should not be running for this test. If the module is okay, it the LED on the module will be flashing. Start the engine and repeat the test. The LED should not be flashing. Bob . . . ________________________________________________________________________________
From: "LarryRobertHelming" <lhelming(at)sigecom.net>
Subject: Re: Dumb question time
Date: Sep 13, 2005
----- Original Message ----- > > > I have an electrically dependant airplane (Lycoming with electric fuel > pumps only). (((((((You need to consider if there are alternative ways to relieve this issue compared with a bullet proof electric setup. Perhaps a mechnical pump inline with the electric. Your future could depend on it.))))))) > > I see from the Z figures that there is no fuseable link in the Batt buss > feed from the battery, the wire is pretty thin and short 6" or less. (((((((((If this wire shorts out, you lose power and maybe start a fire. The shorter the better for fire protection in case of accident. Protect it well from abuse, ie, chaffing.))))))))) > > In my case the feed wire will need to be about 1.5 feet and capable of > supporting a load of about 16 amps max running. (((((Nothing wrong here that I see.))))))))) > > Considering the engine will make like a glider if this lead shorts to > ground (it will be well protected!) what size of wire should I install > and should I install an automotive fuse link...Working on the principle > that a glider is better than a glider with a cockpit fire? (((((((((((The manual of aeroelectric Bob is a good source for determining wire size by length and amp usage. Use it for all your wire selection when amp use is known. If you have a short without some breaker or fuse you might have a fire -- you will lose power regardless of how big your wire is one way or the other. Better to use a fuse of some sort, like the one B&C and others sell. For example, look at the fuse link that lectric Bob schmenatics show going from the alternator output. That would work.))))))))))))) > > Thanks > > Frank (((((((((((Indiana Larry RV7 wired per lectric Bob's schmenatics))))))))) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ " Happiness: like a butterfly, when pursued, is always beyond our grasp, but which, if one sits quietly, may light upon you." Nathanial Hawthorn ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > ________________________________________________________________________________
Date: Sep 13, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Dumb question time
> > > I have an electrically dependant airplane (Lycoming with electric fuel >pumps only). > >I see from the Z figures that there is no fuseable link in the Batt buss >feed from the battery, the wire is pretty thin and short 6" or less. > >In my case the feed wire will need to be about 1.5 feet and capable of >supporting a load of about 16 amps max running. Why 1.5 feet? Battery busses are classically located right next to the battery . . . tradition in the certified side tells us that small, short wires from high current feed sources can be used without protection for that wire . . . it becomes its own fusible link! >Considering the engine will make like a glider if this lead shorts to >ground (it will be well protected!) what size of wire should I install >and should I install an automotive fuse link...Working on the principle >that a glider is better than a glider with a cockpit fire? You've answered your own question. FAT wires for cranking, while potentially strong sources for electrically induced sparks and heat are not fused because (1) they are well protected and (2) the currents they supply in a fault tend to burn away the faulting condition. Long battery cables through lightening holes under the floor will burn a little half-moon clearance in the edge of the hole and all the sparking stops. If you plan to well protect your unusually long, always hot feeder, then while non-conforming with certified tradition, your risks are exceedingly low. I'd rather see you put the battery bus AT the battery but I wouldn't loose any sleep over it if you didn't. A 1.5 foot feeder isn't a big deal. Bob . . . ________________________________________________________________________________
Subject: Dumb question time
Date: Sep 13, 2005
From: "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com>
Thanks Larry, Yes there are two independent pumps however (I have this setup on my current airplane and am comfortable with it). This is a very similar setup to what pretty much all the automotive engined airplanes run. The only single point of failure is the battery feed wire and the battery itself. Actually, just thinking about it, I could simply run a second feed wire from the battery with a fuse link to an independent fuse just for the second pump, seems overkill but for 50 cents worth of wire it would remove the fuse link as the sole barrier from me and eternity. Frank -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of LarryRobertHelming Subject: Re: AeroElectric-List: Dumb question time --> ----- Original Message ----- (Corvallis)" > > > I have an electrically dependant airplane (Lycoming with electric fuel > pumps only). (((((((You need to consider if there are alternative ways to relieve this issue compared with a bullet proof electric setup. Perhaps a mechnical pump inline with the electric. Your future could depend on it.))))))) > > I see from the Z figures that there is no fuseable link in the Batt > buss feed from the battery, the wire is pretty thin and short 6" or less. (((((((((If this wire shorts out, you lose power and maybe start a fire. The shorter the better for fire protection in case of accident. Protect it well from abuse, ie, chaffing.))))))))) > > In my case the feed wire will need to be about 1.5 feet and capable of > supporting a load of about 16 amps max running. (((((Nothing wrong here that I see.))))))))) > > Considering the engine will make like a glider if this lead shorts to > ground (it will be well protected!) what size of wire should I install > and should I install an automotive fuse link...Working on the > principle that a glider is better than a glider with a cockpit fire? (((((((((((The manual of aeroelectric Bob is a good source for determining wire size by length and amp usage. Use it for all your wire selection when amp use is known. If you have a short without some breaker or fuse you might have a fire -- you will lose power regardless of how big your wire is one way or the other. Better to use a fuse of some sort, like the one B&C and others sell. For example, look at the fuse link that lectric Bob schmenatics show going from the alternator output. That would work.))))))))))))) > > Thanks > > Frank (((((((((((Indiana Larry RV7 wired per lectric Bob's schmenatics))))))))) ________________________________________________________________________________
Subject: Dumb question time
Date: Sep 13, 2005
From: "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com>
Thanks...Ahh I wondered if the 16ga wire was supposed to act as its own fuse that answers that one. The unusually long feeder was such that I could get to it easily to maintain the buss. On the RV if you out it right on the back of the firewall it will be tough to get to. I have spent a few excutiating hours on my back in the footwell so this seems a way to avoid that possibility. Thanks for your help. Frank -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L. Nuckolls, III Subject: Re: AeroElectric-List: Dumb question time --> (Corvallis)" > > > I have an electrically dependant airplane (Lycoming with electric >fuel pumps only). > >I see from the Z figures that there is no fuseable link in the Batt >buss feed from the battery, the wire is pretty thin and short 6" or less. > >In my case the feed wire will need to be about 1.5 feet and capable of >supporting a load of about 16 amps max running. Why 1.5 feet? Battery busses are classically located right next to the battery . . . tradition in the certified side tells us that small, short wires from high current feed sources can be used without protection for that wire . . . it becomes its own fusible link! >Considering the engine will make like a glider if this lead shorts to >ground (it will be well protected!) what size of wire should I install >and should I install an automotive fuse link...Working on the principle >that a glider is better than a glider with a cockpit fire? You've answered your own question. FAT wires for cranking, while potentially strong sources for electrically induced sparks and heat are not fused because (1) they are well protected and (2) the currents they supply in a fault tend to burn away the faulting condition. Long battery cables through lightening holes under the floor will burn a little half-moon clearance in the edge of the hole and all the sparking stops. If you plan to well protect your unusually long, always hot feeder, then while non-conforming with certified tradition, your risks are exceedingly low. I'd rather see you put the battery bus AT the battery but I wouldn't loose any sleep over it if you didn't. A 1.5 foot feeder isn't a big deal. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2005
From: Ernest Christley <echristley(at)nc.rr.com>
Subject: Re: AeroElectric-List Digest: 27 Msgs - 09/12/05
AeroElectric-List Digest Server wrote: > >Subject: AeroElectric-List: Bringing alternator on line after engine start. >From: "Rogers, Bob J." <BRogers(at)fdic.gov> > > >My confusion is with the warning in the service manual that I should not >start the engine unless the (main) alternator is already on line. I do >not know the purpose for the warning and I do not comprehend the >possible consequences of waiting to bring the primary alternator on >line. > Bob, think of your foot on the clutch. Do you intentionally rev the engine to redline, and then let your foot slide off the bottom of the clutch pedal? No (unless you're in high school and someone else is buying your tires 8*). You can think of the alternator along the same lines. The regulator works (kinda, sorta) like your foot on the clutch to transfer the insies to the outsies in a controlled manner. The Mazda Service Manual wants the power to come online in a slow, controlled manner so that the regulator can adjust. You don't want to just throw the power on it. You might snap your driveline....er, burn a wire. Cutting the alternator's output line when it is heavily loaded burns up an alternator in the same manner. It's analogous to towing a load up a steep mountain grade and having the driveshaft snap. Can you get your foot off the pedal fast enough not to throw a rod? Maybe, maybe not. But a lot of guys will express a few choice words as they wait for the guage to fall back to reasonable. -- ,|"|"|, | ----===<{{(oQo)}}>===---- Dyke Delta | o| d |o www.ernest.isa-geek.org | ________________________________________________________________________________
Subject: PM alternator on Mazda engine.
Date: Sep 13, 2005
From: "Rogers, Bob J." <BRogers(at)fdic.gov>
It is on a custom made bracket at the bottom of the engine, in-line with the other alternator. One belt from the eccentric shaft pulley drives the primary alternator and the other drives the PM alternator. Both belts drive the water pump. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of William Subject: SPAM::AeroElectric-List: PM alternator on Mazda engine. Bob, Where are you locating the PM alternator? Bill Schertz KIS Cruiser # 4045 Mazda 13-B ----- Original Message ----- From: "Rogers, Bob J." <BRogers(at)fdic.gov> Subject: AeroElectric-List: Bringing alternator on line after engine start. > > > I am building a Mustang II kit plane with a Mazda Rotary 13B engine for > power. The stock alternator is a 60 amp internally regulated > Mitsubishi, which will be my primary source of electrical power. In > addition to the stock alternator, I also have a John Deere 35 amp > permanent magnet (PM) alternator for a backup. ________________________________________________________________________________
Date: Sep 13, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Dumb question time
> > >Thanks...Ahh I wondered if the 16ga wire was supposed to act as its own >fuse that answers that one. > >The unusually long feeder was such that I could get to it easily to >maintain the buss. On the RV if you out it right on the back of the >firewall it will be tough to get to. I have spent a few excutiating >hours on my back in the footwell so this seems a way to avoid that >possibility. That will work. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: LVW problem
> >Bob, > >Thanks. All of my wiring gear is at the hanger, so won't be doing this until >next weekend. > >But in reading your response, I may have identified a/the problem. On the >drawing I have, I interpreted the ground pin (-) as 5 rather than 6, and >that is >how I wired it. After looking more closely at the drawing, the 5's are >different from the 6's - field of view (mentally) just wasn't broad enough. > >Think any damage was done with pin 5 grounded? I guess I will find out when >I rewire and test it. > >Regards, Doug Pins 4, 5 and 9 are all tied together as +14v bus. 3, 6, 7, and 8 are all tied together as ground. Grounding pin 5 would put a short to ground on your +input lead and should open the breaker or fuse. The worst thing that happens is that you might burn a trace on the board. I do note that the installation instruction diagrams print the 9005-100 wiring in red which makes it hard to read and easy to mistake the "5" as a "6". I'll see about fixing that so the drawing is easier to read. Thanks for the heads-up. If your LVW/ABMM module is damaged, I'd be pleased to repair it at no charge. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Power FET's
> > >Hi, > >I seemed to omit the most relevant piece of data.... I am looking for >devices in the 100~200 amp range. I am building an airplane tug and was >intending to set them up in a bridge. The motor is 24 volts. > >Paul Don't think you'll find individual TO-3 devices with that kind of capability. Unlike junction transistors, you can parallel FETS for more current handling capability. What you REALLY want is the lowest practical ON-resistance for the voltage rating of interest. Why TO-3? There are some really nice, big-dog FETS in the TO-247 package (IRFP2907 is typical). See: http://ec.irf.com/v6/en/US/adirect/ir?cmd=catProductDetailFrame&productID=IRFP2907 It has higher resistance cousins with higher votlage ratings. You can parallel as needed for current rating. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: ARC R402A Marker Pin out
> > > Can any one supply me with a sys.pinout for a R402A > Marker? Thanks Bill S. Sorry, not in my data base. Bob . . . ________________________________________________________________________________
From: "William" <wschertz(at)ispwest.com>
Subject: Re: PM alternator on Mazda engine.
Date: Sep 13, 2005
Could you send a picture? Thanks Bill Schertz KIS Cruiser # 4045 ----- Original Message ----- From: "Rogers, Bob J." <BRogers(at)fdic.gov> Subject: RE: SPAM::AeroElectric-List: PM alternator on Mazda engine. > > > It is on a custom made bracket at the bottom of the engine, in-line with > the other alternator. One belt from the eccentric shaft pulley drives > the primary alternator and the other drives the PM alternator. Both > belts drive the water pump. > > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of > William > To: aeroelectric-list(at)matronics.com > Subject: SPAM::AeroElectric-List: PM alternator on Mazda engine. > > > > Bob, > Where are you locating the PM alternator? > > Bill Schertz > KIS Cruiser # 4045 > Mazda 13-B > ----- Original Message ----- > From: "Rogers, Bob J." <BRogers(at)fdic.gov> > To: > Subject: AeroElectric-List: Bringing alternator on line after engine > start. > > >> >> >> I am building a Mustang II kit plane with a Mazda Rotary 13B engine > for >> power. The stock alternator is a 60 amp internally regulated >> Mitsubishi, which will be my primary source of electrical power. In >> addition to the stock alternator, I also have a John Deere 35 amp >> permanent magnet (PM) alternator for a backup. > > > ________________________________________________________________________________
From: CardinalNSB(at)aol.com
Date: Sep 13, 2005
Subject: Re: size for fuseable link
The installation manual for the Electronics International engine monitor UGB16 calls for 1 amp fuses on the "voltage" input line (for the voltage reading) and on the ammenter "shunt" line, to be placed near the shunt which is on the engine side of the firewall. I would like to use a fuseable link instead of a fuse holder, is there any reason not? I plan on 24awg (because of the low amperage, I know the Bob recommended is 22awg) for the link to protect 18awg. How long should the 24awg be? Any other recommendations? Thank you, Skip Simpson ________________________________________________________________________________
From: "Jim Stone" <jrstone(at)insightbb.com>
Subject: Alternator field breaker
Date: Sep 13, 2005
Can someone please tell me if an alternator field breaker is required prior to the switch that controls it Can I use a slot in my fuze panel instead? Others have used 5amps to protect the circuit, does this sound about right? Thanks, Jim HRII ________________________________________________________________________________
Date: Sep 13, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Alternator field breaker
> >Can someone please tell me if an alternator field breaker is required >prior to the switch that controls it >Can I use a slot in my fuze panel instead? >Others have used 5amps to protect the circuit, does this sound about right? >Thanks, >Jim >HRII You can run a fuse if you don't use crowbar ov protection. It's the design goal of crowbar ov protection to deliberately open the upstream power protection . . . a CB has been recommended for ease of dealing with any nuisance trips. If you don't have ov protection or use some form of series switch ov protection, then supplying field current through a fuse is fine. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Ground power for your airplane
The Samlex 13.8 volt, 23 amp supplies I used to sell for about $175 are now down to $100 retail. See http://www.aaradio.com/cartfile/misc%20html/samlex.html for an exemplar offer. I just purchased one of these for a customer's project and found that I can now buy them retail for less than I used to pay for them wholesale! This is an excellent device for powering up all but the most power hungry gizmos in your airplane during construction or ground maintenance operations. Bob . . . -------------------------------------------------------- < Throughout history, poverty is the normal condition > < of man. Advances which permit this norm to be > < exceeded -- here and there, now and then -- are the > < work of an extremely small minority, frequently > < despised, often condemned, and almost always opposed > < by all right-thinking people. Whenever this tiny > < minority is kept from creating, or (as sometimes > < happens) is driven out of a society, the people > < then slip back into abject poverty. > < > < This is known as "bad luck". > < -Lazarus Long- > <------------------------------------------------------> http://www.aeroelectric.com ________________________________________________________________________________
Date: Sep 13, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: size for fuseable link
> >The installation manual for the Electronics International engine monitor >UGB16 calls for 1 amp fuses on the "voltage" input line (for the voltage >reading) and on the ammenter "shunt" line, to be placed near the shunt >which is on >the engine side of the firewall. I would like to use a fuseable >link instead >of a fuse holder, is there any reason not? > >I plan on 24awg (because of the low amperage, I know the Bob recommended is >22awg) for the link to protect 18awg. How long should the 24awg be? Any >other recommendations? > >Thank you, Skip Simpson Fusible part needs to be 4awg steps or more SMALLER than the strand of wire to be protected. 24AWG would be used with 20AWG. See: http://aeroelectric.com/articles/fuselink/fuselink.html What you propose would be okay. B&C has the fusible link kits which include the fiberglas sleeving shown in the fabrication article. Bob . . . ________________________________________________________________________________
Date: Sep 13, 2005
Subject: Re: Alternator field breaker
From: "Matt Prather" <mprather(at)spro.net>
Hi Jim, Do you have a crowbar over voltage protection system? If so, it is somewhat conceivable that you might get a nuisance trip of that system which would cause the fuse to be blown. That would disable the charging system for the duration of that flight unless the fuse panel is mounted in a place accessible to the pilot. Don't get us going on the topic of whether fuses should be accessible in flight unless you want another long discussion (check the archive). It would, however, be logical to replace the switch with a pullable breaker. Regards, Matt- > > > Can someone please tell me if an alternator field breaker is required > prior to the switch that controls it Can I use a slot in my fuze panel > instead? > Others have used 5amps to protect the circuit, does this sound about > right? Thanks, > Jim > HRII > > ________________________________________________________________________________
Date: Sep 14, 2005
From: Jan de Jong <jan.de.jong(at)xs4all.nl>
Subject: Re: Ground power for your airplane
Thank you Bob for this pointer to Samlex 13.8 volt, 23 amp. Small question if I may: to what extent can the output be floated? Jan de Jong ________________________________________________________________________________
Date: Sep 14, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Ground power for your airplane
> >Thank you Bob for this pointer to Samlex 13.8 volt, 23 amp. >Small question if I may: to what extent can the output be floated? > >Jan de Jong If memory serves me correctly, the (+) and (-) outputs from this product are totally isolated from all three leads to ac mains. Bob . . . ________________________________________________________________________________
From: "Jim Stone" <jrstone(at)insightbb.com>
Subject: Re: Alternator field breaker
Date: Sep 14, 2005
Yes, I have the LR3 so I understand the CB would be best. Thanks, Jim ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> Subject: Re: AeroElectric-List: Alternator field breaker > > > >> >> >>Can someone please tell me if an alternator field breaker is required >>prior to the switch that controls it >>Can I use a slot in my fuze panel instead? >>Others have used 5amps to protect the circuit, does this sound about >>right? >>Thanks, >>Jim >>HRII > > You can run a fuse if you don't use crowbar ov protection. > It's the design goal of crowbar ov protection to deliberately > open the upstream power protection . . . a CB has been > recommended for ease of dealing with any nuisance trips. > > If you don't have ov protection or use some form of series > switch ov protection, then supplying field current through > a fuse is fine. > > Bob . . . > > > ________________________________________________________________________________
Date: Sep 14, 2005
From: Bernard Despins <bdespins(at)telusplanet.net>
Subject: Re: Alternator field breaker
So if using the ov protection built into the LR3C from B & C Specialty, you would suggest using a circuit breaker instead of a fuse? Bernard Despins Robert L. Nuckolls, III wrote: >>Can someone please tell me if an alternator field breaker is required >>prior to the switch that controls it >>Can I use a slot in my fuze panel instead? >> >> >> > > You can run a fuse if you don't use crowbar ov protection. > > > If you don't have ov protection or use some form of series > switch ov protection, then supplying field current through > a fuse is fine. > > Bob . . . > ________________________________________________________________________________
From: "Wayne Berg" <wfberg(at)msn.com>
Subject: Tire valve extension
Date: Sep 14, 2005
Does anyone have a source for tire valve extentions that avoids having to remove wheel pants to inflate tires? I know I've seen the add before but have lost the flier. ________________________________________________________________________________
Date: Sep 14, 2005
Subject: Re: Tire valve extension
From: Gerry Holland <gholland@gemini-resourcing.com>
> > Does anyone have a source for tire valve extentions that avoids having to > remove wheel pants to inflate tires? I know I've seen the add before but have > lost the flier. Try: http://www.aircraftextras.com/Valve-ext.htm I have one here in UK from them. Works great! Gerry Holland gholland@gemini-resourcing.com +44 7808 402404 (Mobile) +44 1249 700633 (Direct) +44 01225 436104 (Office) +44 870 7059985 (Fax) Gemini Resourcing Limited Hartham Park, Corsham, Wilts. SN13 0RP - UK Main: +44 1249 700630 Fax: +44 8707 051315 Website - http://www.gemini-resourcing.com DISCLAIMER: This message may contain privileged and confidential information. If you think for any reason this message has been addressed in error you must not copy or disseminate it and we would ask you to notify us immediately by return e-mail to info@gemini-resourcing.com. Internet emails are not necessarily secure. Gemini Resourcing Limited is registered in England with its address at: Hartham Park, Corsham, Wilts. SN13 0RP, England. Regards Gerry ________________________________________________________________________________
Date: Sep 14, 2005
From: Dj Merrill <deej(at)thayer.dartmouth.edu>
Subject: Re: Tire valve extension
Wayne Berg wrote: > > Does anyone have a source for tire valve extentions that avoids having to remove wheel pants to inflate tires? I know I've seen the add before but have lost the flier. > I picked some up at a local auto parts store (Autozone I think). You should be able to find them just about anywhere. -Dj -- Dj Merrill Sportsman 2+2 Builder #7118 "Many things that are unexplainable happen during the construction of an airplane." --Dave Prizio, 30 Aug 2005 "TSA: Totally Screwing Aviation" ________________________________________________________________________________
Date: Sep 14, 2005
From: rd2(at)evenlink.com
Subject: Re: Tire valve extension
> Does anyone have a source for tire valve extentions that avoids having to remove wheel pants to inflate tires? I know I've seen the add before but have lost the flier. > Didn't know such thing existed - if the tire has an extensiion exceeding the pant, how does it turn ? :) I've got capped holes on the pants - remove the cap, inflate replace the cap. Valves are a bit far and awkward to reach, but doable (would like to extend them a bit if sshort extensions are available; the auto ones are too long). Rumen ________________________________________________________________________________
Date: Sep 13, 2005
From: "Michael J. Dark" <darkmich(at)wsu.edu>
Subject: Flat wire?
Has anyone looked at this for any applications? I'm not sure how it would hold up corrosion and shielding-wise, but it seems interesting for threading cable runs in tight spots. http://www.decord.com/dewire.htm -- Michael J. Dark, D.V.M. darkmich(at)wsu.edu ________________________________________________________________________________
From: "Bill Denton" <bdenton(at)bdenton.com>
Subject: Avionics Wiring Hub
Date: Sep 14, 2005
I'm sure most of you are familiar with the Fast Stack wiring hubs offered by Approach Systems. http://www.approach-systems.com/test.asp I'm curious as to the pro's and con's of constructing one myself for use in a homebuilt aircraft. Does anyone have any experience with such a project? Could it be constructed in something like an aluminum Radio Shack "project box" which would be riveted/bolted to the cockpit side of the firewall? Would it be okay to carry the power and ground leads through the box to a DB connector, that would be connected to the individual avionics fuses/circuit breakers and the avionics ground bus? Any other "gotchas" anybody can think of? Thanks! ________________________________________________________________________________
Date: Sep 14, 2005
From: Dj Merrill <deej(at)thayer.dartmouth.edu>
Subject: Re: Tire valve extension
rd2(at)evenlink.com wrote: > Didn't know such thing existed - if the tire has an extensiion exceeding > the pant, how does it turn ? :) > > I've got capped holes on the pants - remove the cap, inflate replace the > cap. Valves are a bit far and awkward to reach, but doable (would like to > extend them a bit if sshort extensions are available; the auto ones are too > long). > > Rumen Hi Rumen, You temporarily put the extensions on to allow you to put air in easily, them remove them before moving the plane. Basically, remove the wheel pant cap, screw on the extension, check air, remove the extension, and put the cap back on your wheel pant. Hope this helps! :-) -Dj -- Dj Merrill Sportsman 2+2 Builder #7118 "Many things that are unexplainable happen during the construction of an airplane." --Dave Prizio, 30 Aug 2005 "TSA: Totally Screwing Aviation" ________________________________________________________________________________
Subject: Tire valve extension
Date: Sep 14, 2005
From: "Mark R Steitle" <mark.steitle(at)austin.utexas.edu>
This a bit far out there, but since this is the Aero-Electric list I will bring it up anyway. I'm wondering how some vehicles in the the auto/motorcycle world manage to monitor tire pressures, and could this be easily adapted to OBAM aircraft? Mark S. > Didn't know such thing existed - if the tire has an extensiion exceeding > the pant, how does it turn ? :) > > I've got capped holes on the pants - remove the cap, inflate replace the > cap. Valves are a bit far and awkward to reach, but doable (would like to > extend them a bit if sshort extensions are available; the auto ones are too > long). > > Rumen ________________________________________________________________________________
Date: Sep 14, 2005
From: sgettings(at)cfl.rr.com
Subject: Re: Tire valve extension
----- Original Message ----- From: rd2(at)evenlink.com Date: Wednesday, September 14, 2005 3:31 pm Subject: Re: AeroElectric-List: Tire valve extension rd2(at)evenlink.com > > > > > Does anyone have a source for tire valve extentions that avoids > having to > remove wheel pants to inflate tires? I know I've seen the add > before but > have lost the flier. > > > > Didn't know such thing existed - if the tire has an extensiion > exceedingthe pant, how does it turn ? :) > > I've got capped holes on the pants - remove the cap, inflate > replace the > cap. Valves are a bit far and awkward to reach, but doable (would > like to > extend them a bit if sshort extensions are available; the auto ones > are too > long). > > Rumen > Try MSC Industrial Direct, page 2406: http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=2406&PMT4NO=1377093&PMT4TP=*ITPD Scott Gettings ________________________________________________________________________________
Subject: Avionics Wiring Hub
Date: Sep 14, 2005
From: "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com>
Having kinda "been there" before I can offer you this. For a simple VFR setup (radio,audio,Transponder and alitude encoder) it was about as much as I wanted to do in terms of complexity by buying the boxes and wiring from scratch. It was made somewhat confusing because different manufacturers call the same wiring terminal by different names. So trying to get the right output into the right input of the next box caused some head scratching. I guess I spent at least 10 hours of wiring all those pesky connectors, fourtunatly I did not make any mistakes. I'm now just about to wire and IFR airplane and there is no way I'm doing that myself from scratch. For me it was either the approach system or get a custom harness made. Quite honestly I found John Stark's pricing on a custom harness to be very reasonable, in fact his avionics pricing looked a little cheaper than most others making the custom harness pretty cheap considering the work it avoided. The Approach system looked very flexible but unless I was intending to do upgrades I had a hard time seeing the point. I think if you are considering building one you are opting for an awful lot of work...If you do this stuff evry day or you're an electronics hobbyist maybe but to me I got better things to do. Frank -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Bill Denton Subject: AeroElectric-List: Avionics Wiring Hub --> I'm sure most of you are familiar with the Fast Stack wiring hubs offered by Approach Systems. http://www.approach-systems.com/test.asp I'm curious as to the pro's and con's of constructing one myself for use in a homebuilt aircraft. Does anyone have any experience with such a project? Could it be constructed in something like an aluminum Radio Shack "project box" which would be riveted/bolted to the cockpit side of the firewall? Would it be okay to carry the power and ground leads through the box to a DB connector, that would be connected to the individual avionics fuses/circuit breakers and the avionics ground bus? Any other "gotchas" anybody can think of? Thanks! ________________________________________________________________________________
Subject: Tire valve extension
Date: Sep 14, 2005
From: "BPA" <BPA(at)bpaengines.com>
Look in Street Rod Magazine. If memory serves me, there was c company that made valve stems that were about 3/4 of an inch longer than regular valve stems. Don't know if they are still available or if the company is even in existence. Allen Barrett Barrett Precision Engines, Inc. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mark R Steitle Subject: RE: AeroElectric-List: Tire valve extension This a bit far out there, but since this is the Aero-Electric list I will bring it up anyway. I'm wondering how some vehicles in the the auto/motorcycle world manage to monitor tire pressures, and could this be easily adapted to OBAM aircraft? Mark S. > Didn't know such thing existed - if the tire has an extensiion exceeding > the pant, how does it turn ? :) > > I've got capped holes on the pants - remove the cap, inflate replace the > cap. Valves are a bit far and awkward to reach, but doable (would like to > extend them a bit if sshort extensions are available; the auto ones are too > long). > > Rumen ________________________________________________________________________________
Date: Sep 14, 2005
From: Sean Stephens <schmoboy(at)cox.net>
Subject: My Z-13/Z-20 Changes (Opinions and a Question)
I've taken Z-13/Z-20 and modified it a bit for a RV-10 with the battery in the tail. Please have a look and let me know if somethings just plain wrong. ( be gentle, I'm new at this :) ) <http://rv10.stephensville.com/myZ13-20K.pdf> 1. Moved main power distribution bus feed from battery contactor to starter contactor. 2. Local airframe ground of the main battery in the tail. The question I have is the feed from the e-bus contactor (will be up front in the plane) and the fuselink on that feed to the battery bus in the tail. Suggestions for resizing these for an ~8 foot run up to the front? Any other precautions there? TIA... -Sean RV-10 #40303 ________________________________________________________________________________
Date: Sep 14, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Alternator field breaker
> > >So if using the ov protection built into the LR3C from B & C Specialty, >you would suggest using a circuit breaker instead of a fuse? > >Bernard Despins Correct. This is shown on all drawings provided by B&C and by the 'Connection where the B&C products are illustrated. Bob . . . ________________________________________________________________________________
From: "Hoffmann D- Remscheid" <Hoffmann.RS@t-online.de>
Subject: flap control Cessna
Date: Sep 15, 2005
Hello by following this thread backwards I have found that all my questions concerning flap control for my homebuilt have in principle already been answered by the Cessna solution. They use a feedback of the flap position to the panel via mechanical cable as a simple and ingenious way. Is there anybody who has done the same thing more recently and could kindly provide me with some information or drawings, eventually from the Cessna maintenance manual? Greetings Richard Richard Hoffmann Am Wiesenhang 45 D-42859 Remscheid Germany ________________________________________________________________________________
From: "Hoffmann D- Remscheid" <Hoffmann.RS@t-online.de>
Subject: LED - flashing beacon
Date: Sep 15, 2005
Hello, for my homebuilt I want to build a beacon using these white super LED's, three in series (3 * 3,5V 10.5V). For 12V systems this seems ideal to me. The only disadvantage is that you need a constant current source, favourably in combination with a flashing device. Has anybody done this before? I don't want to invent the wheel twice (;-)). Greetings Richard ________________________________________________________________________________
Date: Sep 15, 2005
From: N5SL <nfivesl(at)yahoo.com>
Subject: Tire valve extension
Good Morning Mark: Our new jeep has this feature and I found out when I swapped one of the wheels with the spare after a flat. Here is an interesting article that explains how it works: http://www.wjjeeps.com/tpms.htm Scott Laughlin www.cooknwithgas.com 601XL / Corvair Working on Instrument Panel Mark R Steitle wrote: I'm wondering how some vehicles in the the auto/motorcycle world manage to monitor tire pressures, and could this be easily adapted to OBAM aircraft? Mark S. --------------------------------- Click here to donate to the Hurricane Katrina relief effort. ________________________________________________________________________________
Date: Sep 15, 2005
From: Bernard Despins <bdespins(at)telusplanet.net>
Subject: Re: Alternator field breaker
The difficulty I'm having is that in my Velocity XLRG (all electric, dual everything except propellers), the auxiliary alternator, regulator, and battery are all in the rear. The auxiliary bus does not come to the front of the plane. A circuit breaker would not be accessible. Is it worth running a wire to the front and back and place a circuit breaker on the panel? I do have a circuit breaker for the main alternator field. Bernard Despins Robert L. Nuckolls, III wrote: > <>So if using the ov protection built into the LR3C from B & C Specialty, > you would suggest using a circuit breaker instead of a fuse? > > Bernard Despins > > > Correct. This is shown on all drawings provided by B&C and by > the 'Connection where the B&C products are illustrated. > > Bob . . . > > ________________________________________________________________________________
Subject: LED - flashing beacon
Date: Sep 15, 2005
From: "Lloyd, Daniel R." <LloydDR(at)wernerco.com>
You can buy the flashing device at http://www.strobe-direct.com/catalog/Able2Products/led_accessories.htm#1 1.1002 but be warned that flashing LED's might not meet the intensity requirements. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Hoffmann D- Remscheid Subject: AeroElectric-List: LED - flashing beacon <Hoffmann.RS@t-online.de> Hello, for my homebuilt I want to build a beacon using these white super LED's, three in series (3 * 3,5V 10.5V). For 12V systems this seems ideal to me. The only disadvantage is that you need a constant current source, favourably in combination with a flashing device. Has anybody done this before? I don't want to invent the wheel twice (;-)). Greetings Richard ________________________________________________________________________________
Subject: Tire valve extension
Date: Sep 15, 2005
From: "Greg Young" <gyoung@cs-sol.com>
Interesting - they use the space inside a tubeless tire for the transmitter. Now we need to find one that works with a tube. Greg Young > > Good Morning Mark: > > Our new jeep has this feature and I found out when I swapped > one of the wheels with the spare after a flat. Here is an > interesting article that explains how it works: > > http://www.wjjeeps.com/tpms.htm > > > Scott Laughlin > www.cooknwithgas.com > 601XL / Corvair > Working on Instrument Panel > > Mark R Steitle wrote: > I'm wondering how some vehicles in the the auto/motorcycle > world manage to monitor tire pressures, and could this be > easily adapted to OBAM aircraft? > > Mark S. ________________________________________________________________________________
Subject: Tire valve extension
Date: Sep 15, 2005
From: "Mark R Steitle" <mark.steitle(at)austin.utexas.edu>
Scott, Thanks for the link. Sounds interesting, but it looks like it would be difficult to retrofit into an a/c. I like their sending units being incorporated into the valve stem. Dakota Digital (www.dakotadigital.com) has a kit (gauge and 4 sensors) for $399. A bit pricey, but looks like it would work. From what I've read on the Lancair list, the Lancair ES is very sensitive to tire pressures. Incorrect tire pressure linked to nose wheel shimmy, and in more than one case, nose gear collapse. So, this isn't just a neat idea for me, if it could help prevent nose gear collapse, it could pay for itself very quickly. Mark S. Lancair ES/N208TX -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of N5SL Subject: RE: AeroElectric-List: Tire valve extension Good Morning Mark: Our new jeep has this feature and I found out when I swapped one of the wheels with the spare after a flat. Here is an interesting article that explains how it works: http://www.wjjeeps.com/tpms.htm Scott Laughlin www.cooknwithgas.com 601XL / Corvair Working on Instrument Panel Mark R Steitle wrote: I'm wondering how some vehicles in the the auto/motorcycle world manage to monitor tire pressures, and could this be easily adapted to OBAM aircraft? Mark S. --------------------------------- Click here to donate to the Hurricane Katrina relief effort. ________________________________________________________________________________
Subject: Tire valve extension
Date: Sep 15, 2005
From: "Mark R Steitle" <mark.steitle(at)austin.utexas.edu>
Scott, On second thought, I don't think this would work with tube type tires. The Pressure Pro tire pressure monitor uses sensors that screw onto the valve stem. I guess that is a possibility. Also, there is one called TireChek that detects tire inflation by measuring the distance the axel is from the ground (clever). As a tire looses air, the axel gets closer to the ground. However, it appears that they are not yet in production. Interesting approach to the problem though. Mark S. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mark R Steitle Subject: RE: AeroElectric-List: Tire valve extension Scott, Thanks for the link. Sounds interesting, but it looks like it would be difficult to retrofit into an a/c. I like their sending units being incorporated into the valve stem. Dakota Digital (www.dakotadigital.com) has a kit (gauge and 4 sensors) for $399. A bit pricey, but looks like it would work. From what I've read on the Lancair list, the Lancair ES is very sensitive to tire pressures. Incorrect tire pressure linked to nose wheel shimmy, and in more than one case, nose gear collapse. So, this isn't just a neat idea for me, if it could help prevent nose gear collapse, it could pay for itself very quickly. Mark S. Lancair ES/N208TX -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of N5SL Subject: RE: AeroElectric-List: Tire valve extension Good Morning Mark: Our new jeep has this feature and I found out when I swapped one of the wheels with the spare after a flat. Here is an interesting article that explains how it works: http://www.wjjeeps.com/tpms.htm Scott Laughlin www.cooknwithgas.com 601XL / Corvair Working on Instrument Panel Mark R Steitle wrote: I'm wondering how some vehicles in the the auto/motorcycle world manage to monitor tire pressures, and could this be easily adapted to OBAM aircraft? Mark S. --------------------------------- Click here to donate to the Hurricane Katrina relief effort. ________________________________________________________________________________
Date: Sep 15, 2005
Subject: Re: Alternator field breaker
From: "Matt Prather" <mprather(at)spro.net>
Is the auxiliary alternator a PM type or conventional (field current controlled)? Matt- > > > The difficulty I'm having is that in my Velocity XLRG (all electric, > dual everything except propellers), the auxiliary alternator, regulator, > and battery are all in the rear. The auxiliary bus does not come to > the front of the plane. A circuit breaker would not be accessible. Is > it worth running a wire to the front and back and place a circuit > breaker on the panel? I do have a circuit breaker for the main > alternator field. > > Bernard Despins > > Robert L. Nuckolls, III wrote: > >> <>So if using the ov protection built into the LR3C from B & C >> Specialty, you would suggest using a circuit breaker instead of a >> fuse? >> >> Bernard Despins >> >> >> Correct. This is shown on all drawings provided by B&C and by >> the 'Connection where the B&C products are illustrated. >> >> Bob . . . >> >> > > ________________________________________________________________________________
Date: Sep 15, 2005
From: Bernard Despins <bdespins(at)telusplanet.net>
Subject: Re: Alternator field breaker
It is conventional controlled by an LR3C regulator. Bernard Despins Matt Prather wrote: > >Is the auxiliary alternator a PM type or conventional (field current >controlled)? > > >Matt- > > > >> >> >>The difficulty I'm having is that in my Velocity XLRG (all electric, >>dual everything except propellers), the auxiliary alternator, regulator, >> and battery are all in the rear. The auxiliary bus does not come to >>the front of the plane. A circuit breaker would not be accessible. Is >>it worth running a wire to the front and back and place a circuit >>breaker on the panel? I do have a circuit breaker for the main >>alternator field. >> >>Bernard Despins >> >>Robert L. Nuckolls, III wrote: >> >> >> >>><>So if using the ov protection built into the LR3C from B & C >>>Specialty, you would suggest using a circuit breaker instead of a >>>fuse? >>> >>>Bernard Despins >>> >>> >>> Correct. This is shown on all drawings provided by B&C and by >>> the 'Connection where the B&C products are illustrated. >>> >>> Bob . . . >>> >>> >>> >>> >> >> > > > > ________________________________________________________________________________
From: Kevin Horton <khorton01(at)rogers.com>
Subject: Re: Alternator field breaker
Date: Sep 15, 2005
I believe Bob recommends a CB because it has a faster response time than a fuse. If you are prepared to put a fuse in a location where it is not accessible in flight, why not put the CB in a similar location? In principle, if the system is properly designed, there should not be any nusiance CB trips. So if the CB trips and shuts down the alternator, then you would want to leave it tripped until you get on the ground. Kevin Horton On 15 Sep 2005, at 10:02, Bernard Despins wrote: > > > The difficulty I'm having is that in my Velocity XLRG (all electric, > dual everything except propellers), the auxiliary alternator, > regulator, > and battery are all in the rear. The auxiliary bus does not come > to the > front of the plane. A circuit breaker would not be accessible. Is it > worth running a wire to the front and back and place a circuit breaker > on the panel? I do have a circuit breaker for the main alternator > field. > > Bernard Despins > > Robert L. Nuckolls, III wrote: > > >> <>So if using the ov protection built into the LR3C from B & C >> Specialty, >> you would suggest using a circuit breaker instead of a fuse? >> >> Bernard Despins >> >> >> Correct. This is shown on all drawings provided by B&C and by >> the 'Connection where the B&C products are illustrated. >> >> Bob . . . >> >> >> ________________________________________________________________________________
Date: Sep 15, 2005
Subject: Re: Alternator field breaker
From: "Matt Prather" <mprather(at)spro.net>
CB's are SLOWER than ATC fuses. Probably partly due to having a mechanism which has to be actuated in order to interrupt. When at 10x rating (10A rating, 100A fault), fuses may take well less than 100ms (0.1sec) while CB's trip no faster than 800ms or so depending on the design.. CB's slowness makes them slightly less prone to nuisance trips. There are slow blow fuses that are slower still, but less common. A fusible link might be consider a slow blow (slow replacement) fuse. Regards, Matt- > > > I believe Bob recommends a CB because it has a faster response time > than a fuse. > > If you are prepared to put a fuse in a location where it is not > accessible in flight, why not put the CB in a similar location? > > In principle, if the system is properly designed, there should not be > any nusiance CB trips. So if the CB trips and shuts down the > alternator, then you would want to leave it tripped until you get on > the ground. > > Kevin Horton > > On 15 Sep 2005, at 10:02, Bernard Despins wrote: > >> >> >> The difficulty I'm having is that in my Velocity XLRG (all electric, >> dual everything except propellers), the auxiliary alternator, >> regulator, >> and battery are all in the rear. The auxiliary bus does not come to >> the >> front of the plane. A circuit breaker would not be accessible. Is it >> worth running a wire to the front and back and place a circuit breaker >> on the panel? I do have a circuit breaker for the main alternator >> field. >> >> Bernard Despins >> >> Robert L. Nuckolls, III wrote: >> >> >>> <>So if using the ov protection built into the LR3C from B & C >>> Specialty, >>> you would suggest using a circuit breaker instead of a fuse? >>> >>> Bernard Despins >>> >>> >>> Correct. This is shown on all drawings provided by B&C and by the >>> 'Connection where the B&C products are illustrated. >>> >>> Bob . . . >>> >>> >>> > > ________________________________________________________________________________
Date: Sep 15, 2005
Subject: Breaker Interrupt Rating
From: "Matt Prather" <mprather(at)spro.net>
In the past, I know there has been dispute about breaker interrupt ratings, and whether the crowbar overly stresses the breakers being used. While noodling around to confirm my response to Mr. Horton's comment, I found the following webpage about Klixon 28V breakers. http://www.ti.com/snc/products/controls/acb-7274.htm I thought it interesting because the interrupt rating for some of these devices is listed as "unlimited" (1/2A to 5A rating - will cover the field breaker). The lowest rating I found was 2000A which is still more than anyone else's "worst case" analysis of the CB circuit dynamics. This all supports Mr. Nuckolls testimony on the subject. Using one of these CBs without ever replacing it would seem to provide plenty of (datasheet supported) reliability with the loads we've been discussing. Regards, Matt- ________________________________________________________________________________
Date: Sep 15, 2005
From: Bernard Despins <bdespins(at)telusplanet.net>
Subject: Re: Alternator field breaker
My auxiliary bus is essentially the 10 position fuse holder from B and C. Adding a circuit breaker in the back would add parts and connections that a simple fuse avoids. Bernard Despins Kevin Horton wrote: > >I believe Bob recommends a CB because it has a faster response time >than a fuse. > >If you are prepared to put a fuse in a location where it is not >accessible in flight, why not put the CB in a similar location? > > >Kevin Horton > >On 15 Sep 2005, at 10:02, Bernard Despins wrote: > > > >> >> >>The difficulty I'm having is that in my Velocity XLRG (all electric, >>dual everything except propellers), the auxiliary alternator, >>regulator, >>and battery are all in the rear. The auxiliary bus does not come >>to the >>front of the plane. A circuit breaker would not be accessible. Is it >>worth running a wire to the front and back and place a circuit breaker >>on the panel? I do have a circuit breaker for the main alternator >>field. >> >>Bernard Despins >> >>Robert L. Nuckolls, III wrote: >> >> >> >> > > ________________________________________________________________________________
Date: Sep 15, 2005
From: Mickey Coggins <mick-matronics(at)rv8.ch>
Subject: degaussing (demagnetizing) my roll bar
I've read somewhere the instructions on how to degauss or demagnetize the roll bar on my RV8, but I can't find them now. If I recall correctly, it involves wrapping a power cord around the roll bar and running a lot of current through the cord. Hopefully someone can give me something a bit more detailed. I have a fairly strong bit of magnetism in my roll bar, and I want to do this before I install my windscreen. Many thanks, Mickey -- Mickey Coggins http://www.rv8.ch/ #82007 finishing ________________________________________________________________________________
From: CardinalNSB(at)aol.com
Date: Sep 15, 2005
Subject: Re: avionics wiring hub
I too had been thinking about a diy avionics hub, but now I wonder how useful it will be v. the added parts count/potential for failure. When I started my project I was bewildered by the avionics wiring, and the hub seemed like a good idea, I now know there was a lot of power sharing and amp sharing and light wires, which made it all a mess (since I didn't have schematics back then). The way I look at it (small ga plane), the audio panel/intercom will be fairly permanently wired in, so taking it out will be a big job, so I don't plan to upgrade it for a long time. The mikes/speakers/intercoms are all tied to the audio panel. Big deal to remove. But I do hope to upgrade my "radios" in the near future, so initially I had thought of the "hub", but.. For the radio/nav/gps (I have a garmin 300/ki202 and a narco mk12d/825), there are only 4-5 wires from each to the audio panel and now that I have learned the secret bobby pin tool for my audio panel's incoming Molex connectors that doesn't seem so bad. The cdi's will run direct from the radio tray to the cdi, so that comes out with a simple connector on the cdi. I didn't want to run the cdi wiring into the hub and then coming out of the hub, lots more parts there. Power and grounds will run direct, could run through a d sub. So to pop out a radio rack, pop off the cdi connector, remove power and ground, and use the bobby pin to take out 5 pins from the back of the audio panel. So when the non-waas 430's get dumped on the market... I could run the radio audio/power/ground through a single d sub which would be easier to disconnect, but more work and more parts, v. pulling a few molex connectors. The transponder power/ground will go direct, the connect to the encoder is already a d sub, I haven't decided what to do about the transponder connect to the gps. So when I first got my newbie quote of $800 to install a Icom 200 and $2000 to install a vfr gps, the "hub" seemed attractive. Now, for a basic ga setup, I don't think so. I am starting this soon, I hope I am right, welcome any thoughts?. Skip Simpson ________________________________________________________________________________
Date: Sep 15, 2005
From: Guy Buchanan <bnn(at)nethere.com>
Subject: Re: degaussing (demagnetizing) my roll bar
If the cord wrap doesn't work, contact Sacramento Sky Ranch. They rent a demagnetizer with instructions. I did my Kitfox forward frame in just a few minutes. At 01:56 PM 9/15/2005, you wrote: > > >I've read somewhere the instructions on >how to degauss or demagnetize the roll >bar on my RV8, but I can't find them >now. If I recall correctly, it involves >wrapping a power cord around the roll >bar and running a lot of current through >the cord. Hopefully someone can give me >something a bit more detailed. I have a >fairly strong bit of magnetism in my roll >bar, and I want to do this before I install >my windscreen. > >Many thanks, >Mickey > >-- >Mickey Coggins >http://www.rv8.ch/ >#82007 finishing > > Guy Buchanan K-IV 1200 / 582 / 99% done, thanks to Bob Ducar. ________________________________________________________________________________
From: "LarryRobertHelming" <lhelming(at)sigecom.net>
Subject: Re: degaussing (demagnetizing) my roll bar
Date: Sep 15, 2005
I am wondering...........how did your roll bar get so heavily magnetized and how did you determine it was? I have demagnetized some things like read/write heads on a reel to reel tape recorder. The process was to attach an electro magnet with a piece of tape between so it did not actually touch metal to metal with the head and very slowly move it away while it was energized. Then turn it off. do not archive cause I do not know the value of this info, if any. Indiana Larry ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ " Happiness: like a butterfly, when pursued, is always beyond our grasp, but which, if one sits quietly, may light upon you." Nathaniel Hawthorne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ----- Original Message ----- From: "Mickey Coggins" <mick-matronics(at)rv8.ch> Subject: AeroElectric-List: degaussing (demagnetizing) my roll bar > > > I've read somewhere the instructions on > how to degauss or demagnetize the roll > bar on my RV8, but I can't find them > now. If I recall correctly, it involves > wrapping a power cord around the roll > bar and running a lot of current through > the cord. Hopefully someone can give me > something a bit more detailed. I have a > fairly strong bit of magnetism in my roll > bar, and I want to do this before I install > my windscreen. > > Many thanks, > Mickey > > -- > Mickey Coggins > http://www.rv8.ch/ > #82007 finishing > > > ________________________________________________________________________________
From: "Robert G. Wright" <armywrights(at)adelphia.net>
Subject: Tire valve extension
Date: Sep 15, 2005
Does anybody think that you'll get some interestingly high readings while you're at altitude???? Rob -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mark R Steitle Subject: RE: AeroElectric-List: Tire valve extension Scott, On second thought, I don't think this would work with tube type tires. The Pressure Pro tire pressure monitor uses sensors that screw onto the valve stem. I guess that is a possibility. Also, there is one called TireChek that detects tire inflation by measuring the distance the axel is from the ground (clever). As a tire looses air, the axel gets closer to the ground. However, it appears that they are not yet in production. Interesting approach to the problem though. Mark S. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mark R Steitle Subject: RE: AeroElectric-List: Tire valve extension Scott, Thanks for the link. Sounds interesting, but it looks like it would be difficult to retrofit into an a/c. I like their sending units being incorporated into the valve stem. Dakota Digital (www.dakotadigital.com) has a kit (gauge and 4 sensors) for $399. A bit pricey, but looks like it would work. From what I've read on the Lancair list, the Lancair ES is very sensitive to tire pressures. Incorrect tire pressure linked to nose wheel shimmy, and in more than one case, nose gear collapse. So, this isn't just a neat idea for me, if it could help prevent nose gear collapse, it could pay for itself very quickly. Mark S. Lancair ES/N208TX -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of N5SL Subject: RE: AeroElectric-List: Tire valve extension Good Morning Mark: Our new jeep has this feature and I found out when I swapped one of the wheels with the spare after a flat. Here is an interesting article that explains how it works: http://www.wjjeeps.com/tpms.htm Scott Laughlin www.cooknwithgas.com 601XL / Corvair Working on Instrument Panel Mark R Steitle wrote: I'm wondering how some vehicles in the the auto/motorcycle world manage to monitor tire pressures, and could this be easily adapted to OBAM aircraft? Mark S. --------------------------------- Click here to donate to the Hurricane Katrina relief effort. ________________________________________________________________________________
From: "Craig Berland" <cberland(at)systems3.net>
Subject: degaussing (demagnetizing) my roll bar
Date: Sep 15, 2005
Mickey, take it to a grind shop or mag particle shop. They can de-mag it. Should take less than 5 minutes. Craig Berland >> I've read somewhere the instructions on > how to degauss or demagnetize the roll > bar on my RV8, but I can't find them > now. If I recall correctly, it involves > wrapping a power cord around the roll > bar and running a lot of current through > the cord. Hopefully someone can give me > something a bit more detailed. I have a > fairly strong bit of magnetism in my roll > bar, and I want to do this before I install > my windscreen. > > Many thanks, > Mickey > > -- > Mickey Coggins > http://www.rv8.ch/ > #82007 finishing > > ________________________________________________________________________________
From: "Eric M. Jones" <emjones(at)charter.net>
Subject: RE: Breaker Interrupt Rating
Date: Sep 15, 2005
>In the past, I know there has been dispute about breaker interrupt >ratings, and whether the crowbar overly stresses the breakers being used. >While noodling around to confirm my response to Mr. Horton's comment, I >found the following webpage about Klixon 28V breakers. >http://www.ti.com/snc/products/controls/acb-7274.htm >I thought it interesting because the interrupt rating for some of these >devices is listed as "unlimited" (1/2A to 5A rating - will cover the field >breaker). The lowest rating I found was 2000A which is still more than >anyone else's "worst case" analysis of the CB circuit dynamics. This all >supports Mr. Nuckolls testimony on the subject. Using one of these CBs >without ever replacing it would seem to provide plenty of (datasheet >supported) reliability with the loads we've been discussing. Regards, Matt Clever engineers those Klixon guys. Or maybe not.... Interrupting capacity per UL1077/IEC934/EN60934 PC1 is defined as the maximum current that a circuit breaker must interrupt-just one time-without causing a safely hazard. KaaPowwwww......Operating a circuit breaker outside its published ratings is a bad idea. Crowbarring cicuit breakers was an historic method used in the olden days. Good thing that better methods like Linear Non-crowbar OVP's were invented. This problem has been fought to the death. It points out how poor an email list system is at retaining consensus (or illuminating disagreements!) Recently a number of issues that I thought were buried have arrisen like Zombies. Oh well, we must be getting close to Halloween. Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 (508) 764-2072 Don't worry about people stealing an idea. If it's original, you will have to ram it down their throats." -- Howard Aiken ________________________________________________________________________________
Date: Sep 15, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Alternator field breaker
> > >My auxiliary bus is essentially the 10 position fuse holder from B and >C. Adding a circuit breaker in the back would add parts and connections >that a simple fuse avoids. > >Bernard Despins A fuse protected field supply is perfectly acceptable for safety and as long as you don't get nuisance trips, perfectly acceptable for operational considerations as well. Given that nuisance trips are rare and generally easy to fix, your risk of intractable difficulties is low. Bob . . . ________________________________________________________________________________
Date: Sep 15, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: RE: Breaker Interrupt Rating
> > > >In the past, I know there has been dispute about breaker interrupt > >ratings, and whether the crowbar overly stresses the breakers being used. > >While noodling around to confirm my response to Mr. Horton's comment, I > >found the following webpage about Klixon 28V breakers. > > >http://www.ti.com/snc/products/controls/acb-7274.htm > > >I thought it interesting because the interrupt rating for some of these > >devices is listed as "unlimited" (1/2A to 5A rating - will cover the field > >breaker). The lowest rating I found was 2000A which is still more than > >anyone else's "worst case" analysis of the CB circuit dynamics. This all > >supports Mr. Nuckolls testimony on the subject. Using one of these CBs > >without ever replacing it would seem to provide plenty of (datasheet > >supported) reliability with the loads we've been discussing. Regards, Matt > >Clever engineers those Klixon guys. Or maybe not.... Interrupting capacity >per UL1077/IEC934/EN60934 PC1 is defined as the maximum current that a >circuit breaker must interrupt-just one time-without causing a safely >hazard. KaaPowwwww......Operating a circuit breaker outside its published >ratings is a bad idea. Crowbarring cicuit breakers was an historic method >used in the olden days. Don't know about "olden days" . . . and to be sure, high interrupt currents in the 100+ vac worlds are a whole 'nother ballgame. I have discussed and provided bench testing, field experience and extensive investigation of specs and even called my guru at Eaton/Cutler-Hammer who couldn't understand what all the fuss was about . . . > Good thing that better methods like Linear Non-crowbar OVP's were invented. So the crowbar method is "bad" (or should I say "non-better") . . . again????? In the aviation/military world, and per the specifications I published, the breakers we recommend and sell must be tested at max available interrupt currents in the thousands of amps AND STILL BE FUNCTIONAL AFTER THE TEST. Of course, due to internal resistance of the breaker itself plus additional wiring resistances limit the REAL currents to much less than POTENTIAL currents at 28v. The testing, the field experience and specifications do not support the allegations. Crowbar was selected because it met DESIGN GOALS for not increasing the number places where series resistances would contribute to voltage regulation instability for systems where bus sense and field supply are on the same feeder. "Ammeter wiggle" has plagued thousands of GA aircraft for decades due to this phenomenon. Another design goal of achieving a solid state solution for replacement of electro-mechanical relays in a time when robust, hv transistors were much more expensive. All of the things you you've offered were considered back then and crowbar won out on all counts. Years later, some have decided to play the specs game when in fact, they were blatantly guilty of mis-interpreting and/or ignoring component specs just as I've been accused of doing. See: http://aeroelectric.com/articles/spike.pdf Some numbers tossed around in this thread weren't as wild as the 700A fault currents claimed at the beginning of the latest discussion started but were no more accurate. You guys are very long on throwing interpretation of specs around and short on both hard data and experience. Please, sell all the series shut down devices you wish . . . shucks, if you want to peddle ov RELAYS . . . those are fine too. But if the only way you can sell your products/ideas is to claim my products/ ideas are deficient and use concocted numbers and claims to support it, it's a sad day for the CONSUMERS of devices who must make decisions on data no better than that offered by a commercial for laundry soap. The challenge still stands. Take any breaker you like and throw it across a 12v battery as many times as you like and tell me how many times you have to whack it to trash it. I've not been able to do it on my bench, maybe your's is uglier than mine. I've done all the testing I'm going to do to defend myself against the indefensible . . . the interminable string of allegations. It's time for you guys to put up or shut up. Show me the smoke . . . By the way Eric. I've been trying to identify a connector/tool combination that works well with that sample of coax I got from you in Plymouth. It may be great coax but I found it very user-unfriendly to work with. If you're going to recommend and/or sell it, I'll suggest you recommend/supply tools and connectors to mate with it. A step-by-step instruction sheet to aid the builder in getting it right by the second or third try would be good too . . . Bob . . . ________________________________________________________________________________
Date: Sep 15, 2005
From: Bob White <bob@bob-white.com>
Subject: Re: LED - flashing beacon
Hi Richard, I would suggest using some a solid state switch to turn the power on to the LED's. Run them in parallel with a series resistor for each LED. This effectively gives you a constant current source for the LED's. You might be able to increase the intensity by popping them with higher than rated currents (smaller resistor), but still keeping the junction temperature down on the diode because of the duty cycle. Say 20 % on 80 % off and experiment with 1.5X or 2X current levels. (I haven't tried this.) There's no reason to limit yourself to 3 LED's either. You can put more LED's in parallel to get more light out. Bob W. "Hoffmann D- Remscheid" <Hoffmann.RS@t-online.de> wrote: > > Hello, > > for my homebuilt I want to build a beacon using these white super LED's, three in series (3 * 3,5V 10.5V). For 12V systems this seems ideal to me. > The only disadvantage is that you need a constant current source, favourably in combination with a flashing device. Has anybody done this before? I don't want to invent the wheel twice (;-)). > > Greetings Richard > > > > > > > > -- http://www.bob-white.com N93BD - Rotary Powered BD-4 (real soon) Prewired EC2 Cables - http://www.roblinphoto.com/shop/ ________________________________________________________________________________
Date: Sep 15, 2005
From: GMC <gmcnutt(at)shaw.ca>
Subject: Re: degaussing (demagnetizing) my roll bar
Hi Mickey Is your fuselage located such that the roll bar is close to (underneath) fluorescent lights. My roll bar & other parts became magnetized sitting under a four tube fluorescent light fixture in garage. Magnetism bled off after aircraft was moved to hangar. George in Langley BC Mickey Coggins wrote: > >I've read somewhere the instructions on >how to degauss or demagnetize the roll >bar -----------snip---------- I have a >fairly strong bit of magnetism in my roll >bar, and I want to do this before I install >my windscreen. > > > > ________________________________________________________________________________
Date: Sep 15, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: Alternator field breaker
> >CB's are SLOWER than ATC fuses. Probably partly due to having a mechanism >which has to be actuated in order to interrupt. Every device that functions based on heating effects can be shown to have what is called an I(squared)*T constant. Look over the specs for fuses and you'll find this term used in many discussions of trip characteristics. This characteristic is relatively constant for any given device and it simply suggests that if you double the heating current, the trip time will go down to 1/4th the original value. When you compare the thermal mass of the heat-sensitive element in a fuse http://www.aeroelectric.com/Pictures/ATC-25_1.jpg with that in a breaker http://www.aeroelectric.com/Pictures/W31_3.jpg it's intuitive that the breaker will be much slower to respond to similar over-current conditions. Inded, inspection of manufacturer's data on various over-current protection devices . . . http://aeroelectric.com/Mfgr_Data illustrates the relative reaction speeds of a variety of protective devices for similar overloads. Check out the ANL series critters at say 5x overload. These "fuses" are slower than most breakers. >When at 10x rating (10A rating, 100A fault), fuses may take well less than >100ms (0.1sec) while CB's trip no faster than 800ms or so depending on the >design.. > >CB's slowness makes them slightly less prone to nuisance trips. >There are slow blow fuses that are slower still, but less common. >A fusible link might be consider a slow blow (slow replacement) fuse. There are two classes of "nuisance trips" that have been discussed lately. Most discussions of NT have focused on the crowbar ov protection system. This particular nuisance trip is a characteristic of the OVP device and will be the same irrespective of the style of over current protection. The other class of NT arises when the protected system is subject to prolonged, in-rush currents when loaded with devices like motors (5-100x but short), very large lamps (20-70x also short) and pitot heaters (4x and very long). These kinds of loads drive consideration for selection of protective devices like thermal breakers, fuses rated for "slow-blow" characteristics (ANL is one class) or even fusible links. Bob . . . ________________________________________________________________________________
Date: Sep 15, 2005
Subject: Re: RE: Breaker Interrupt Rating
From: "Matt Prather" <mprather(at)spro.net>
Hi Eric, What does the following text mean? "High Short Circuit Capacity For its miniature size, the 2TC series offers unusually high current interrupting capacity. Overloads up to 6,000 amps at 28 VDC or 2,0003,500 amps at 120 VAC, 400 Hz can be safely interrupted without affecting calibration or operating performance in the standard 2TC series." http://www.ti.com/snc/products/controls/acb-2tc.htm Is the fundamental interrupt capability of a 7274 (mentioned before) different from a 2TC? You might say that calibration and operating performance applies to the behavior during only one firey interrupt. However, the calibration curve only goes to 1000x the rating. On a 1A breaker, 6000A (within spec) is 6000x the rating, and hence off the calibration curve published for the breaker. Something's missing if interpreted as you suggest. The verbage above says that the breaker will remain calibrated to spec up to 6000A. What to do? Somehow getting smoked would seem to characterize the device as un-calibrated. Maybe the verbage means what it says. Interrupt a 6000A load and the calibration is still good. I notice that the bigger breakers are rated to lower ultimate interrupt capability. Why would a more robust device have a lower rating? Thermal issues? Bigger breaker stays closed longer during the ramp-up in current and gets hotter? I realize that these breakers meet the MIL/UL specs, but just? In the semiconductor industry that I work in, there are lots of JEDEC specs that we have to meet in order to play ball. Many of them we meet with LOTS of margin usually because when a device first came out none of the producers are sure how to solve some of initial challenges. A little IP later, and the JEDEC specs aren't even interesting - a new way to cut the knot has been devised. Datasheets exist to cover the backsides of the producer, but also to provide useful information about how to apply a product correctly. If a breaker isn't reusable after a real-world hard fault, that's one of the industry's best-kept dirty little secrets. None the less, maybe you're right, and Rutan is right. Minimum specs end up being performance ceilings. Regards, Matt- > > > > >>In the past, I know there has been dispute about breaker interrupt >> ratings, and whether the crowbar overly stresses the breakers being >> used. While noodling around to confirm my response to Mr. Horton's >> comment, I found the following webpage about Klixon 28V breakers. > >>http://www.ti.com/snc/products/controls/acb-7274.htm > >>I thought it interesting because the interrupt rating for some of these >> devices is listed as "unlimited" (1/2A to 5A rating - will cover the >> field breaker). The lowest rating I found was 2000A which is still >> more than anyone else's "worst case" analysis of the CB circuit >> dynamics. This all supports Mr. Nuckolls testimony on the subject. >> Using one of these CBs without ever replacing it would seem to provide >> plenty of (datasheet supported) reliability with the loads we've been >> discussing. Regards, Matt > > > Clever engineers those Klixon guys. Or maybe not.... Interrupting > capacity per UL1077/IEC934/EN60934 PC1 is defined as the maximum > current that a circuit breaker must interrupt-just one time-without > causing a safely hazard. KaaPowwwww......Operating a circuit breaker > outside its published ratings is a bad idea. Crowbarring cicuit > breakers was an historic method used in the olden days. Good thing that > better methods like Linear Non-crowbar OVP's were invented. > > This problem has been fought to the death. It points out how poor an > email list system is at retaining consensus (or illuminating > disagreements!) Recently a number of issues that I thought were buried > have arrisen like Zombies. Oh well, we must be getting close to > Halloween. > > Regards, > Eric M. Jones > www.PerihelionDesign.com > 113 Brentwood Drive > Southbridge MA 01550-2705 > (508) 764-2072 > > Don't worry about people stealing an idea. If it's original, you will > have to ram it down their throats." > -- Howard Aiken > > ________________________________________________________________________________
Date: Sep 16, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: RE: Breaker Interrupt Rating
> > >Bob: might I suggest you should use, for these that make claims and fail to >back them up with their own testing as you have requested time and time >again without response, the DELETE key. It would be the EASIEST thing to do . . . But I cannot ignore echoes of some words by an intellectual super-hero of mine who once offered: "Perhaps the sentiments contained in the following pages, are not yet sufficiently fashionable to procure them general favor; a long habit of not thinking a thing wrong, gives it a superficial appearance of being right, and raises at first a formidable outcry in defence of custom. But the tumult soon subsides. Time makes more converts than reason." Common Sense by Thomas Paine 1776 The topic of his missive was to discuss the simple ideas of good government and the rights of individuals to live without fear of force or fraud against person or property (liberty for short). But the paragraph is a simple-idea unto itself. If you do not consistently and calmly defend a simple-idea by which you operate, then after a time a LACK OF DEFENSE is easily misconstrued to be a demonstration of weakness or falsity of the idea. Many folks in both government and science depend on the age old idea of simply wearing the opposition down with tenacity and the ease with which allegations can be tossed . . . one can conduct an effective offense even without UNDERSTANDING of the ideas under discussion! I heartily encourage folks who find these conversations troubling, boring, or useless to use the DELETE key as their personal feelings dictate. But if I'm to stay true to my craft, I cannot allow time to elevate bad science to the level of believable simply because I'm weary of defending good science. Nor do I belive it's a good idea to "take the discussions off-list" . . . our system of justice used to be founded on a judgement by our peers. One can acquire neither justice as an individual nor effect the propagation of good science by conducing the discussions in the dark. Thank you for your concerns my friend but as long as I can muster the energy, I'm not the one who is in need of rescue. Bob . . . ________________________________________________________________________________
Date: Sep 16, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: RE: Breaker Interrupt Rating
> > > > By the way Eric. I've been trying to identify a connector/tool > > combination that works well with that sample of coax I got > > from you in Plymouth. It may be great coax but I found it > > very user-unfriendly to work with. If you're going to recommend > > and/or sell it, I'll suggest you recommend/supply tools and > > connectors to mate with it. A step-by-step instruction sheet > > to aid the builder in getting it right by the second or third > > try would be good too . . . > >I used this wire too. Since it was the first time I've ever >done anything with coax, I just thought working with coax was >hard. Now I feel a bit better! I got the stuff cut, trimmed, >and crimped, but I don't have 100% confidence in the quality >of my work. I was planning on finding out how good it works >on the first flight. What tool and connectors did you use? This coax is smaller than RG400/142 and larger than RG174. I have connectors that mate nicely with both sizes and neither was suited to this task. There might be an intermediate sized connector available but they're not in common distribution by any of my favorite suppliers. Bob . . . ________________________________________________________________________________
From: "Eric M. Jones" <emjones(at)charter.net>
Subject: Re: degaussing (demagnetizing) my roll bar
Date: Sep 16, 2005
>I'm not really sure how it got magnetized, but it came this >way from Van's. Seems to be a common problem. I checked it >by putting a simple orienteering compass near it. It swings >the needle when about a foot away. My panel mounted compass >will be less than a foot away. Thanks for the hints. Best regards, Mickey Hi Mickey, If you take your compass and examine a can of beans from your pantry, you will find it is magnetized. Almost every piece of ferrous metal slowly drifts into the magnetic state of its environment. Using the 4130 metal airframe for a ground also causes problems, since currents through the metal cause magnetization. Some alloys are worse than others. Aircraft tubing is almost all 4130 so choosing another alloy is not practical. Eliminating magnetization is a process of scrambling the domains by alternating the magnetic field while slowly reducing the field to zero. A spool of wire, and a variable output transformer (variac) are the tools you need; but how much and where is your individual experiment. > Is your fuselage located such that the roll bar is close to (underneath) > fluorescent lights. My roll bar & other parts became magnetized sitting > under a four tube fluorescent light fixture in garage. Magnetism bled > off after aircraft was moved to hangar. > > George in Langley BC George, I think it is more likely that moving the aircraft 90 degrees was the solution. But just wait a few months to see what happened. Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 (508) 764-2072 "Nothing is too wonderful to be true." James Clerk Maxwell, discoverer of electromagnetism "Too much of a good thing can be wonderful." Mae West, discoverer of personal magnetism ________________________________________________________________________________
From: "Eric M. Jones" <emjones(at)charter.net>
Subject: RE: Breaker Interrupt Rating
Date: Sep 16, 2005
Matt-- > You might say that calibration and operating performance applies to the > behavior during only one firey interrupt. However, the calibration curve > only goes to 1000x the rating. Please look again. That's 10X the rating or 1000%. Bob claims the curves can be extended. This is a fundamental disagreement. Another problem is how the device will operate at 12V when the trip times are for 28V. There is an important alloy difference in contacts good for 12 and 28 volts. I don't know, but I can imagine a scenario where the contacts would weld without sufficient heat to cause the bimetal strip to flex enough. At any rate, it is wrong to think a device specified for 28V will "work fine" at 12-14V. It is also wrong to think that AC applications are more rigorous than DC. Paul Messinger's tests show that the discharge can be far greater than the CB is spec'd for. This devolved into an argument about battery resistances, but I believe Paul (since I am somewhat party to his testing). > Datasheets exist to cover the backsides of the producer, but also to > provide useful information about how to apply a product correctly. > If a breaker isn't reusable after a real-world hard fault, that's one of the industry's best-kept dirty little secrets. CBs fail all the time, but less so when they are properly located in real systems. In the worst case fault a CB only has to work three times to be approved for that current. "Crowbar" usage is a special application. There are plenty of guys using two motorcycle batteries in parallel, or newer batteries with phenomenal cranking capabilities. I believe Paul's 400 Amp result would be easy to get, and the CB is not correct for the application. Adding a resistor seems easy but requires a pulse rated part. You can't test the crowbar design into a good design. > None the less, maybe you're right, and Rutan is right. Minimum specs end up being performance ceilings. Agreed. But consider that in a mature product the performance tolerance is so small that it does not encourage improvement in the product. This is the best that can be done in a particular design. And it's a good thing, not a bad thing. Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 (508) 764-2072 "Everything you've learned in school as "obvious" becomes less and less obvious as you begin to study the universe. For example, there are no solids in the universe. There's not even a suggestion of a solid. There are no absolute con- tinuums. There are no surfaces. There are no straight lines." - R. Buckminster Fuller ________________________________________________________________________________
Date: Sep 16, 2005
From: Ernest Christley <echristley(at)nc.rr.com>
Subject: RE: Breaker Interrupt Rating
Eric M. Jones wrote: >Clever engineers those Klixon guys. Or maybe not.... Interrupting capacity >per UL1077/IEC934/EN60934 PC1 is defined as the maximum current that a >circuit breaker must interrupt-just one time-without causing a safely >hazard. KaaPowwwww......Operating a circuit breaker outside its published >ratings is a bad idea. Crowbarring cicuit breakers was an historic method >used in the olden days. Good thing that better methods like Linear >Non-crowbar OVP's were invented. Eric, it is my understanding, and the understanding of everyone I've ever dealt with, that the purpose of a circuit breaker is to break the circuit when something gets shorted. The only failure mode I've ever heard of is that the breaker trips easier as it gets old/wears out/is abused. In fact, when I worked as an electrician's helper in high school, the guy carried around an extra pair of old cutter for the express purpose of cutting through a pair of wires to cause the breaker to trip (so he'd know without a doubt that he was turning off the correct breaker to kill a circuit). That is, he would routinely throw a dead short to trip the breaker. I cannot fathom what 'safely hazard' can be caused by tripping a breaker. THAT IS WHAT THEY ARE THERE FOR. Their whole purpose for existing is to be a resettable circuit interrupton. The worst case scenario is that the breaker want stay closed if you ever hit it too hard. How long would D-Square stay in business if they advertised a breaker that "worked most of the time, but would sometimes fail with a dead short"? They would be laughed out of any industry that had anything to do with electricity. If the whole point is to open the circuit after something bad happens...and we're not going to reset it ('cause we have enough battery reserve to get where we were going, and we'll troubleshoot there), then what's wrong with it staying open after something bad happens? Could you please explain to the casual reader what these safety hazards are? Any example of it ever happening? Please, don't limit yourself to aviation applications. Any anectdotal example anywhere? -- ,|"|"|, | ----===<{{(oQo)}}>===---- Dyke Delta | o| d |o www.ernest.isa-geek.org | ________________________________________________________________________________
From: "Wayne Berg" <wfberg(at)msn.com>
Subject: Re: Tire valve extension
Date: Sep 15, 2005
Thanks Gary. Exactly what I wanted. Wayne Berg ----- Original Message ----- From: Gerry Holland Subject: Re: AeroElectric-List: Tire valve extension > > Does anyone have a source for tire valve extentions that avoids having to > remove wheel pants to inflate tires? I know I've seen the add before but have > lost the flier. Try: http://www.aircraftextras.com/Valve-ext.htm I have one here in UK from them. Works great! Gerry Holland gholland@gemini-resourcing.com +44 7808 402404 (Mobile) +44 1249 700633 (Direct) +44 01225 436104 (Office) +44 870 7059985 (Fax) Gemini Resourcing Limited Hartham Park, Corsham, Wilts. SN13 0RP - UK Main: +44 1249 700630 Fax: +44 8707 051315 Website - http://www.gemini-resourcing.com DISCLAIMER: This message may contain privileged and confidential information. If you think for any reason this message has been addressed in error you must not copy or disseminate it and we would ask you to notify us immediately by return e-mail to info@gemini-resourcing.com. Internet emails are not necessarily secure. Gemini Resourcing Limited is registered in England with its address at: Hartham Park, Corsham, Wilts. SN13 0RP, England. Regards Gerry ________________________________________________________________________________
Date: Sep 16, 2005
From: GMC <gmcnutt(at)shaw.ca>
Subject: Re: degaussing (demagnetizing)
Hi Eric You could well be right. If anyone wants to check for magnetism in their workshop try checking with your hydro utility company they often have a meter [gausmeter ?] that you can borrow at no charge. I discovered that my fluorescent fixtures generated significant magnetic fields. George in Langley BC Eric M. Jones wrote: > > > > > >>I'm not really sure how it got magnetized, but it came this >>way from Van's. Seems to be a common problem. I checked it >>by putting a simple orienteering compass near it. It swings >>the needle when about a foot away. My panel mounted compass >>will be less than a foot away. Thanks for the hints. Best regards, Mickey >> >> > >Hi Mickey, > >If you take your compass and examine a can of beans from your pantry, you >will find it is magnetized. Almost every piece of ferrous metal slowly >drifts into the magnetic state of its environment. Using the 4130 metal >airframe for a ground also causes problems, since currents through the metal >cause magnetization. Some alloys are worse than others. Aircraft tubing is >almost all 4130 so choosing another alloy is not practical. > >Eliminating magnetization is a process of scrambling the domains by >alternating the magnetic field while slowly reducing the field to zero. A >spool of wire, and a variable output transformer (variac) are the tools you >need; but how much and where is your individual experiment. > > > >>Is your fuselage located such that the roll bar is close to (underneath) >>fluorescent lights. My roll bar & other parts became magnetized sitting >>under a four tube fluorescent light fixture in garage. Magnetism bled >>off after aircraft was moved to hangar. >> >>George in Langley BC >> >> > >George, > >I think it is more likely that moving the aircraft 90 degrees was the >solution. But just wait a few months to see what happened. > >Regards, >Eric M. Jones > > > ________________________________________________________________________________
From: "Eric M. Jones" <emjones(at)charter.net>
Subject: RE: Breaker Interrupt Rating
Date: Sep 16, 2005
echristley(at)nc.rr.com Ernest, >Eric, it is my understanding, and the understanding of everyone I've ever >dealt >with, that the purpose of a circuit breaker is to break the circuit when >something >gets shorted. The only failure mode I've ever heard of is that the breaker >trips easier as it gets old/wears out/is abused. In fact, when I worked as >an electrician's helper in high school, the guy carried around an extra >pair >of old cutter for the express purpose of cutting through a pair of wires to >cause >the breaker to trip (so he'd know without a doubt that he was turning off >the correct breaker to kill a circuit). That is, he would routinely throw >a >dead short to trip the breaker. Cool! I met a very old electrician (everyone called him "Sparky"), who loved to regale the young engineers by telling them how he would use his bare fingers to determine the voltage...120, 240, and 480 VAC. >I cannot fathom what 'safely hazard' can be caused by tripping a breaker. >THAT >IS WHAT THEY ARE THERE FOR. Their whole purpose for existing is to be a >resettable >circuit interrupton. The worst case scenario is that the breaker want >stay closed if you ever hit it too hard. How long would D-Square stay in >business >if they advertised a breaker that "worked most of the time, but would >sometimes >fail with a dead short"? They would be laughed out of any industry that >had anything to do with electricity. >If the whole point is to open the circuit after something bad happens...and >we're >not going to reset it ('cause we have enough battery reserve to get where >we >were going, and we'll troubleshoot there), then what's wrong with it >staying >open after something bad happens? Could you please explain to the casual >reader >what these safety hazards are? Any example of it ever happening? Please, >don't limit yourself to aviation applications. Any anectdotal example >anywhere? Surely. If you Google ' Circuit Breaker Fail OR Failure' you will find the real world situation. My experience in using hundreds of thousands of circuit breakers or many types is that it is a far more complicated subject than most people believe. Safety hazards include not setting the local surroundings afire. I used to sell crowbar OVPs similar to Bob's. Part of my test fixture was a Tyco P&B Series W28 10A Thermal Circuit Breaker purchased from Digikey. On the first test with a 24V battery as OV, the circuit breaker opened but failed catastrophically. Since the OVP test setup was not a perfect reflection of the real world, I discounted the incident, but later decided to not sell crowbar type OVPs at all. Paul Messinger's 400A measurement used a setup that was an exact duplicate (wire lengths and all) of his aircraft's system. In order for a CB to be rated as "interrupted without damage", it usually only has to do this 3X. Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 (508) 764-2072 Teamwork: " A lot of people doing exactly what I say." (Marketing exec., Citrix Corp.) ________________________________________________________________________________
Date: Sep 16, 2005
From: Mickey Coggins <mick-matronics(at)rv8.ch>
Subject: Re: RE: Breaker Interrupt Rating
>>> By the way Eric. I've been trying to identify a connector/tool >>> combination that works well with that sample of coax I got >>> from you in Plymouth. It may be great coax but I found it >>> very user-unfriendly to work with. If you're going to recommend >>> and/or sell it, I'll suggest you recommend/supply tools and >>> connectors to mate with it. A step-by-step instruction sheet >>> to aid the builder in getting it right by the second or third >>> try would be good too . . . >> >>I used this wire too. Since it was the first time I've ever >>done anything with coax, I just thought working with coax was >>hard. Now I feel a bit better! I got the stuff cut, trimmed, >>and crimped, but I don't have 100% confidence in the quality >>of my work. I was planning on finding out how good it works >>on the first flight. > > > What tool and connectors did you use? This coax is smaller > than RG400/142 and larger than RG174. I have connectors that > mate nicely with both sizes and neither was suited to this > task. There might be an intermediate sized connector available > but they're not in common distribution by any of my favorite > suppliers. I used one of these types of ratcheting crimpers: http://www.steinair.com/images/store/panels/sat001.jpg with this die: http://www.steinair.com/images/store/coaxdie.jpg I also used "standard" "RG400 & RG58" connectors: http://www.steinair.com/images/SA1010F.jpg I put heat shrink around the whole connector like this: http://www.rv8.ch/article.php?story=20050110191323706 I guess if Eric chimes in and comes up with some better hardware, I'll re-do the cables. Probably take about 20 minutes - everything's still open and easy to get to. -- Mickey Coggins http://www.rv8.ch/ #82007 finishing ________________________________________________________________________________
Date: Sep 16, 2005
From: Mickey Coggins <mick-matronics(at)rv8.ch>
Subject: Re: degaussing (demagnetizing) my roll bar
> Eliminating magnetization is a process of scrambling the domains by > alternating the magnetic field while slowly reducing the field to zero. A > spool of wire, and a variable output transformer (variac) are the tools you > need; but how much and where is your individual experiment. Hi Eric, Thanks for the info. Do you think it's a waste of time to do this? Thanks, Mickey -- Mickey Coggins http://www.rv8.ch/ #82007 finishing ________________________________________________________________________________
From: "Dan Checkoway" <dan(at)rvproject.com>
Subject: magneto timing buzz box
Date: Sep 16, 2005
I've scoured the archives and haven't found anything definitive. I want to roll my own "buzz box" for timing my magneto. This can't be too complicated (although it's over my head, else I'd already have done it). Does anybody have a buzz box circuit that works? )_( Dan RV-7 N714D http://www.rvproject.com ________________________________________________________________________________
Date: Sep 16, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: magneto timing buzz box
> >I've scoured the archives and haven't found anything definitive. I want to >roll my own "buzz box" for timing my magneto. This can't be too complicated >(although it's over my head, else I'd already have done it). > >Does anybody have a buzz box circuit that works? I had a schematic for one (I think out of a Sport Aviation article) but I can't put my hands on it. The problem with using an ohmmeter to detect point opening arises from the fact that points in a mag are paralleled with a very low resistance primary winding on the magneto core. It looks like a dead short to most ohmmeters and therefore, difficult to detect when the points open. The "buzz box" used a buzzer to generate a relatively high frequency AC signal that could take advantage of the primary winding's apparent rise in resistance as the excitation frequency went up . . . much easier to tell when the dead-short points opened up. I'm wondering if a milliohmmeter adapter I showed at: http://aeroelectric.com/articles/LowOhmsAdapter_3.pdf wouldn't detect the points opening in a magneto . . . I'll keep an eye out for the article I copied and post it if I find it. Bob . . . ________________________________________________________________________________
Date: Sep 16, 2005
From: D Wysong <hdwysong(at)gmail.com>
Subject: Re: magneto timing buzz box
Is it this one, Bob? http://www.rst-engr.com/kitplanes/KP9910/KP9910.htm D -------------------------- Robert L. Nuckolls, III wrote: > > > >> >>I've scoured the archives and haven't found anything definitive. I want to >>roll my own "buzz box" for timing my magneto. This can't be too complicated >>(although it's over my head, else I'd already have done it). >> >>Does anybody have a buzz box circuit that works? > > > I had a schematic for one (I think out of a Sport Aviation > article) but I can't put my hands on it. The problem with using > an ohmmeter to detect point opening arises from the fact that > points in a mag are paralleled with a very low resistance > primary winding on the magneto core. It looks like a dead > short to most ohmmeters and therefore, difficult to detect when > the points open. The "buzz box" used a buzzer to generate > a relatively high frequency AC signal that could take advantage > of the primary winding's apparent rise in resistance as the > excitation frequency went up . . . much easier to tell when > the dead-short points opened up. > > I'm wondering if a milliohmmeter adapter I showed at: > > http://aeroelectric.com/articles/LowOhmsAdapter_3.pdf > > wouldn't detect the points opening in a magneto . . . > > I'll keep an eye out for the article I copied and post > it if I find it. > > Bob . . . > > > > > > > ________________________________________________________________________________
Date: Sep 16, 2005
From: Charlie England <ceengland(at)bellsouth.net>
Subject: Re: RE: Breaker Interrupt Rating
Eric M. Jones wrote: > >echristley(at)nc.rr.com > >Ernest, > > > >>Eric, it is my understanding, and the understanding of everyone I've ever >>dealt >>with, that the purpose of a circuit breaker is to break the circuit when >>something >>gets shorted. The only failure mode I've ever heard of is that the breaker >>trips easier as it gets old/wears out/is abused. In fact, when I worked as >>an electrician's helper in high school, the guy carried around an extra >>pair >>of old cutter for the express purpose of cutting through a pair of wires to >>cause >>the breaker to trip (so he'd know without a doubt that he was turning off >>the correct breaker to kill a circuit). That is, he would routinely throw >>a >>dead short to trip the breaker. >> >> > >Cool! I met a very old electrician (everyone called him "Sparky"), who loved >to regale the young engineers by telling them how he would use his bare >fingers to determine the voltage...120, 240, and 480 VAC. > > > >>I cannot fathom what 'safely hazard' can be caused by tripping a breaker. >>THAT >>IS WHAT THEY ARE THERE FOR. Their whole purpose for existing is to be a >>resettable >>circuit interrupton. The worst case scenario is that the breaker want >>stay closed if you ever hit it too hard. How long would D-Square stay in >>business >>if they advertised a breaker that "worked most of the time, but would >>sometimes >>fail with a dead short"? They would be laughed out of any industry that >>had anything to do with electricity. >> >> > > > >>If the whole point is to open the circuit after something bad happens...and >>we're >>not going to reset it ('cause we have enough battery reserve to get where >>we >>were going, and we'll troubleshoot there), then what's wrong with it >>staying >>open after something bad happens? Could you please explain to the casual >>reader >>what these safety hazards are? Any example of it ever happening? Please, >>don't limit yourself to aviation applications. Any anectdotal example >>anywhere? >> >> > >Surely. > >If you Google ' Circuit Breaker Fail OR Failure' you will find the real >world situation. My experience in using hundreds of thousands of circuit >breakers or many types is that it is a far more complicated subject than >most people believe. > >Safety hazards include not setting the local surroundings afire. I used to >sell crowbar OVPs similar to Bob's. Part of my test fixture was a Tyco P&B >Series W28 10A Thermal Circuit Breaker purchased from Digikey. On the first >test with a 24V battery as OV, the circuit breaker opened but failed >catastrophically. Since the OVP test setup was not a perfect reflection of >the real world, I discounted the incident, but later decided to not sell >crowbar type OVPs at all. > >Paul Messinger's 400A measurement used a setup that was an exact duplicate >(wire lengths and all) of his aircraft's system. In order for a CB to be >rated as "interrupted without damage", it usually only has to do this 3X. > >Regards, >Eric M. Jones >www.PerihelionDesign.com >113 Brentwood Drive >Southbridge MA 01550-2705 >(508) 764-2072 > You have personal experience using hundreds of thousands of circuit breakers? You must have had an exceedingly long and/or prolific career. If we limit the count to 200,000, that works out to around 15 per work day over a 50 year career if you don't take any vacations. Were they all aircraft style c/b's? ;-) Charlie ________________________________________________________________________________
Subject: Re: magneto timing buzz box
From: "John Schroeder" <jschroeder(at)perigee.net>
Date: Sep 17, 2005
Kitplanes had an article about this a couple of yerars ago. > > Does anybody have a buzz box circuit that works? > > )_( Dan > RV-7 N714D > http://www.rvproject.com ________________________________________________________________________________
Date: Sep 17, 2005
From: <gmcjetpilot(at)yahoo.com>
Subject: Re: Alternator field breaker (solution!)
It sounds like just using an internally regulated alternator (I-VR) like a ND, is easier, simpler and more reliable. If we had cars that needed constant or even occasional circuit breaker resets or fuse replacement, we would have a line of angry people at the dealer and an investigative prime-time news show report. >Bob N.: ..your risk of intractable difficulties (with a crow bar) is low. With a ND alternator, if there is a problem the internal OV protection provides your protection, and YOUR RISK OF INTRACTABLE DIFFICULTIES IS LOW. However if there is some indication of problem, the integrated ALT fault light illuminates or an indication of Lo/Hi volts, manually pull the BIG-OL-FAT-CB on your panel (for the B-lead). I personally recommend** a B-lead CB on the panel that can be pulled and NOT a fuse. The use of a B-lead fuse is recommended on Z drawings, but the use of a CB on the B-lead is common aerospace practice and should be used when using a ND alternator. We know how great CBs are, because Bob recommends them in conjunction with a crow bar and has argued eloquently how reliable they are. Using Fuses on the B-lead is a special use on aircraft and common to automobiles but not airplanes. Also the issue of NOISE is over blown. A CB on the panel will NOT be the reason for electrical system noise. Back in the dark ages with old time external regulated alternators, using mechanical points, noise was an issue, regardless if you used a fuse or a CB on the panel. Modern alternators like the I-VR ND are not noisy. I have NOT heard alternator noise in a car since the 70's. New alternators of modern design used in cars and a single point central grounding wiring scheme in your aircraft will eliminate most if not all noise problems. If you have a ND alternator and hear noise in the audio system , remove the alternator and have it tested, repaired since it is not normal or fix a ground problem. Manually pulling the CB is totally OK with the CB, and it is a little more humane to the CB than throwing a dead short across it (not that there is anything wrong with that, I think?). I like having a way to disconnect the B-lead and isolating the alternator, regardless of where the voltage regulator is. PUT THAT BIG 40-60 AMP CIRCUIT BREAKER PROUDLY ON YOUR PANEL.** Pulling the B-lead CB on the panel isolates the alternator positively. There is no nuisance trips or worry of CB life. G ** All the above information is from a non-expert and should not be used unless you understand it and accept the fact (low risk) that a ND alternator failure will be a rare event. Further these rare failures will be benign. The extreme failure, where there is smoke and brimfire, of specific 40 amp and 60 amp ND alternator models mentioned on this list, are unsubstantiated, unconfirmed theory yet to be quantified and documented. Bob dont write me about paradigms. I am wrong and you are right and the "crow bar" is the best thing ever. I am crazy not to use it. Please, don't follow my advise/suggestions and do what Bob says. ________________________________________________________________________________
From: "Ron Brown" <romott(at)sprintmail.com>
Subject: Re: magneto timing buzz box
Date: Sep 17, 2005
I have successfully timed the Slick mag on my Lycoming IO360 using a digitial ohm meter than can resolve 0.1 ohm. I have a $50 Radioshack meter similar to http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F008%5F002%5F000&product%5Fid=22%2D812 If you have a digital ohm meter that will display ohms in 0.1 ohm increments, it should work too. MAKE SURE THERE IS NO FUEL IN THE FUEL/CARB. THE REALLY SAFE WAY TO DO THIS IS TO REMOVE ONE PLUG FROM EACH CYLINDER. CAUTION - DO NOT HAVE THE OHM METER CONNECTED WHILE THE IMPULSE COUPLING SNAPS - GOOD CHANCE YOU WILL DAMAGE YOUR OHM METER DUE THE HIGH ENERGY AT THE P LEAD WHEN THE MAG FIRES. 1. Turn the engine in the normal direction until the impulse coupling snaps - #1 firing position - can be verified by holding your finger over the #1 spark plug hole and turn until you get pressure. 2. Turn the prop back wards about 45 degrees. 3. Turn the ignition switch on. Connect one lead of the ohm meter to the P lead for the mag. (I actually connect to the back of my mag/starter switch - easier to get to in my plane). 4. Connect the other ohm meter lead the engine case. 5. My meter shows 0.7 ohms with the points closed. 6. Now, very slowly move the prop in the counter clockwise direction until the resistance changes to 0.4- 0.5 ohms. You will need to let the ohm meter settle for a couple of seconds after each movement - the mag will supply some voltage when it is moving. 7. The timing marks are in two locations. On the front of the flywheel facing the engine case split. Mine has markings at 0 TDC, 22 BTDC, and 25 BTDC (before top dead center). 8. The other mark is on the starter ring - and there is a dimple on the upper starter flange that is the zero point. The dimple on the starter ring is covered up by the prop extension cover - but I made a mark out on the ring gear it self. 9. TURN THE IGNITION BACK OFF, REMOVE THE DVM, PRIOR TO TURNING THE ENGINE PAST THE FIRING POINT!!! I have verified this works - two A&P's and their two buzz boxes were used to verify my indications were correct. Of course, if you have access to the buzz boxes, by all means use it instead. But if you have a good DVM, you can use it instead. WORKS!!! Ronnie Brown ________________________________________________________________________________
Date: Sep 17, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: RE: Breaker Interrupt Rating
> > >Eric M. Jones wrote: > > > > > > >Safety hazards include not setting the local surroundings afire. I used to > >sell crowbar OVPs similar to Bob's. Part of my test fixture was a Tyco P&B > >Series W28 10A Thermal Circuit Breaker purchased from Digikey. On the first > >test with a 24V battery as OV, the circuit breaker opened but failed > >catastrophically. Since the OVP test setup was not a perfect reflection of > >the real world, I discounted the incident, but later decided to not sell > >crowbar type OVPs at all. Aha! DATA! now can you share any measurements you took? Wire sizes and lengths? > > > >Paul Messinger's 400A measurement used a setup that was an exact duplicate > >(wire lengths and all) of his aircraft's system. In order for a CB to be > >rated as "interrupted without damage", it usually only has to do this 3X. Really? Again, tell me how I can go to the bench and duplicate his experiment. Bob . . . ________________________________________________________________________________
Date: Sep 17, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: RE: Breaker Interrupt Rating
> > >Matt-- > > > You might say that calibration and operating performance applies to the > > behavior during only one firey interrupt. However, the calibration curve > > only goes to 1000x the rating. > >Please look again. That's 10X the rating or 1000%. Bob claims the curves >can be extended. This is a fundamental disagreement. Paul and Eric call the upper bounds the set of curves limits that should not be exceeded if one is desirous of not "killing" one's breaker. I have a brother in law who became a journeyman electrician and while helping me with some wiring one day, decided that after we had a breaker open on a miss-wired feeder, that it should be replaced. I asked why and he stated that's what he was taught. That was 20 years ago and the same breaker is still in the box. >Another problem is how the device will operate at 12V when the trip times >are for 28V. ???12v versus 28v trip times??? Opening time is an I(squared)*T event that is independent of voltage. Once the latch opens and contact start to move, it's no longer a beaker but a simple switch. Now the physics focus on contact spreading velocity, contact mass and characteristics of load current (resistive, inductive, lamp or some combination of all three) and SYSTEM VOLTAGE. > There is an important alloy difference in contacts good for 12 and 28 volts. Really? Where do you find this on the data sheets . . . or any other document for that matter? >I don't know, but I can imagine a scenario where the contacts would weld >without sufficient heat to cause the bimetal strip to flex enough. At any >rate, it is wrong to think a device specified for 28V will "work fine" at >12-14V. It is also wrong to think that AC applications are more rigorous >than DC. We should consider two separate activities that go on within a breaker: Heat energy dissipated in the current sensor sufficient (1) raise the temperature of the trip mechanism so that (2) a set of switch contacts are caused to open. The trip time is relatively constant irrespective of operating voltage. Temperature rise in the heater is an RMS current and time dependent effect and doesn't care about ac/dc or voltage. The opening the contacts after trip time is where voltage and circuit characteristics matter. It's immaterial whether we consider switches, relays or breakers for this study . . . all three devices need to break a circuit where voltage, source impedance and dynamics (ac/dc) can have an effect on success for any single event and also drives total number of high-stress openings that can be endured before the breaker's SWITCH performance is degraded. >Paul Messinger's tests show that the discharge can be far greater than the >CB is spec'd for. This devolved into an argument about battery >resistances, but I believe Paul (since I am somewhat party to his testing). About which we know nothing. I've published everything I've done on the bench and you've published nothing. Let's talk about specs . . . For example, I could publish a set of curves for any number of products to aid the user in predicting performance over a range of conditions I might anticipate to be common. The fact that my charts and curves end at some particular boundary does not have to mean that venturing outside that boundary is automatically deleterious to the product. > > Datasheets exist to cover the backsides of the producer, but also to > > provide useful information about how to apply a product correctly. > > > If a breaker isn't reusable after a real-world hard fault, that's one > of the industry's best-kept dirty little secrets. > >CBs fail all the time, but less so when they are properly located in real >systems. In the worst case fault a CB only has to work three times to be >approved for that current. "Crowbar" usage is a special application. There >are plenty of guys using two motorcycle batteries in parallel, or newer >batteries with phenomenal cranking capabilities. I believe Paul's 400 Amp >result would be easy to get, and the CB is not correct for the >application. Adding a resistor seems easy but requires a pulse rated part. This battery impedance thing keeps coming up . . . Assume ZERO impedance and then wire per the diagrams and we still can't approach a 400A (started out 700A) mark. Go to the bench my friend. Show me how you get a real 400A event . . . or even a real 200A event. Gather the data and we'll add it to: http://www.aeroelectric.com/articles/Crowbar_OV_Protection/DC_Power_System_Dynamics_C.pdf This article describes the kind of testing and thought processes behind the original design. Make my day, show me where we were wrong. When the crowbar ov module is wired per any of the diagrams I've ever posted, the resulting stresses for crowbar operation do not overstress any breakers I've used or would recommend. The P&B W31 series switch/breakers have been used in Bonanzas and Barons for decades. When we qualified the crowbar ov system onto the turbine powered Bonanza (Lightning) 25 years ago, the same spec sheet was in force: http://www.aeroelectric.com/Mfgr_Data/Breakers/Potter_Brumfield/W2331_DS.pdf Yup, there's a bunch of performance limit specs for interrupt capacity . . . at 50V (Which are conservative). We determined that the real stresses on the breaker for the relatively high crowbar interrupt events was not related to stresses on the heater but on the contact's ability to break the arc . . . which is much more difficult to do at 50VDC (I'm told this is one of big stumbling blocks for a transition to 42V cars . . . arcs start easier and are harder to put out). Beech had a requirement that an ovp system function properly after 50 cycles for qualification purposes. We did engineering testing to hundreds of cycles in 28V systems and determined that the technology was sound. It's even sounder in 14V systems. >You can't test the crowbar design into a good design. "Good" is non quantified. There was no testing done to change the physics. Testing was done to discover the physics we suspected or confirm the physics we already knew. Testing showed that design goals were met without measurable effect on either reliability or performance of the parts used. Opening a 5A breaker with a 150A event does not hurt the heater and contacts of every breaker I've run across. Every breaker tested will open the 150A event hundreds of times without degrading performance. Given that an ov event should be extremely rare (most airplanes will never have one) the confidence level in our investigations was high enough to call the technology certifiable. We do testing all the time to confirm what we know. For example, you can't buy military temp rated parts any more. Nonetheless, we have many requirements to guarantee operation at -55 to +105C. The parts were all made on the same production line and simply screened for the wider operating ranges. We still meet our extended temperature range requirements by TESTING industrial rated parts ourselves. If I could find a breaker manufacturer willing to deliver to a Critical Item Product Function Specification for a breaker that meets my requirements for operation in a crowbar ovp system, they would probably charge me $100,000 for qual testing. Then, the price of what used to be a $15 breaker would now be $100 and guess what? The breaker supplied would most likely come right off their present production line but with a different part number on it. What we're really discussing here is a difference in philosophies. You prefer to interpret specification sheet data as brick walls . . . this is certainly a minimum effort, minimum risk decision. I, and many of my compatriots, understand that components may have capabilities that range well outside published data. Capabilities that can be exploited to good advantage . . . but only if you take the time to understand the simple-ideas that govern the way the part functions. You're certainly within your rights to design within the boundaries suggested by your interpretation of data sheets. But this does not make my design decisions bad or un-desirable because I choose to exploit unspecified but acknowledged and testable capabilities that lie outside the published values. I'd still like to see how one gets 400A to flow through a 5A breaker of any manufacturer. Paul alluded to a 5A breaker with some very low (.004 ohms I think) resistance awhile back. I'd give him $50 for a sample of such a part. But alas, we're still in the dark as to parts tested, test setups crafted, tests conducted, and data derived therefrom. To date, your arguments are supported only by your conservative interpretation of data sheets. > > None the less, maybe you're right, and Rutan is right. Minimum specs > end up being performance ceilings. > > >Agreed. But consider that in a mature product the performance tolerance is >so small that it does not encourage improvement in the product. This is >the best that can be done in a particular design. And it's a good thing, >not a bad thing. ????? What does this mean? Bob . . . ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: RE: Breaker Interrupt Rating
Date: Sep 17, 2005
Bob; I DID post (to this list) the exact specific technical parts etc. details of my test and you seemed never recognize that fact. That I used words and not a schematic is not important in this case as a schematic is not needed with such a simple circuit. I did use a different wiring diagram (of your schematic) to duplicate what is in my aircraft however. But you cannot duplicate my results (as I under stand what you mean by duplicate) unless you use the exact same parts I used. The same identical part, not a part of the same brand and part number is required in this case because of the very wide variation in the parts tolerances. Only if a worst case analysis is properly done and the range of test results is determined can any test be duplicated by another using different physical parts of the same part number. The part to part variation in most cases and clearly in this case is simply too large. Crow bar short circuit currents can vary from well under 100 amps to over 400 amps depending on the parts used and the wiring diagram used to implement the same schematic. Thus any test that results in a current from around 100 amps to around 400 amps is in fact a duplication of another's test results in this case. Where there are small parts variations the duplicated test results will be much closer but NEVER identical. For example the following is true: #1 CB ratings vary widely in resistance and trip time, in fact, close to a 10 -1 variation. between parts of the same brand and parts from other brands. Nothing strange about My CB having an internal resistance 1/10 of the one you used. CB internal resistance can and does vary from approx 0.003 to over 0.030 ohms; a 10-1 variation #2 Battery internal resistance also varies again as much as 10-1 depending on the battery brand and ratings. My batteries have 1/5 to 1/10 the internal resistance of your battery. But then I do not use the Panasonic brand or similar types.I do use a very popular PS625 (dual at that) battery with much higher specifications in most important parameters. Not that the Panasonic is bad but its not nearly the same in several (important to me) electrical specifications. #3 My wiring was an exact duplicate of what I have in my aircraft and is a fraction of what you had in your test. My wiring is less that 1/2 the internal resistance of your test wiring. I measures the battery internal resistance as well as the CB and wiring resistances before and after the testing series. The same CB was used in the simulated worst case test where the current was 700 amps and there were at least 50 tests of the real circuit where the current was 400 amps. No degrading of any part including the SCR in your crow bar circuit which was over stressed several times its max rating. This overstressing and lack of damage does not mean its a good design idea and more importantly does not mean that all CB's will survive with no damage. In this case the main short current drivers are the Battery, CB and wiring resistances. That alone suggests that 400 amps is easy to achieve as the circuit resistance to get 400 amp vs. 130 amps only needs to decrease to 1/3 or so. Bottom line: I had 6 EXPERT, experienced, real electrical engineers review what I have done and ALL agreed with my test setup and suggested 400 amps was not the max current possible as I had not used the worst case analysis parts. I had hoped this issue had gone away months ago as we will never agree. I only post here when I feel my comments are being misquoted to the extreme. Seems that will never end and frankly I am saddened that it seems to continue. The basic issue of OVP crow bar short to open a CB is the real discussion where you believe its a good approach and I disagree is the fundamental issue and the short current is a distraction. Please do not snip this email as it tends to put my comments out of context and change the meaning/intent of my comment. Better yet simply do not reply and we can both put this stupid debate to rest and get on with productive discussions. Paul ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> Subject: Re: AeroElectric-List: RE: Breaker Interrupt Rating > > Really? Again, tell me how I can go to the bench and duplicate > his experiment. > > Bob . . . ________________________________________________________________________________
From: "Greg Campbell" <GregCampbellUSA(at)comcast.net>
Subject: Re: magneto timing buzz box
Date: Sep 17, 2005
Take a look at the $25 kit from www.MagnetoTimer.com and see if that meets your needs. I've built two - it's a fun little soldering project, all the parts are included and identified (taped to the instruction sheet). About an hour of fitting & soldering and you've got a nice tool. The leads coil up and stow inside the open front of the plastic case. Greg ________________________________________________________________________________
From: "Pete Howell" <pete.howell@gecko-group.com>
Subject: FW: Splice 6AWG Wire
Date: Sep 17, 2005
I have one of the in-line maxifuse holders wirth 6AWG wire. One lead is not long enough. How is the best way to splice in a longer piece of 6AWG? ________________________________________________________________________________
From: KITFOXZ(at)aol.com
Date: Sep 17, 2005
Subject: Re: FW: Splice 6AWG Wire
In a message dated 9/17/2005 7:48:16 P.M. Eastern Standard Time, pete.howell@gecko-group.com writes: I have one of the in-line maxifuse holders wirth 6AWG wire. One lead is not long enough. How is the best way to splice in a longer piece of 6AWG? Hello Pete, There are a few ways to splice wires of that size. My choice would be to solder them but, most guys would not have a soldering iron large enough for the job. You would need an iron with a chisel tip and about 120 Watts of heat. The Weller SP120 would be a good choice. Strip the insulation off the wires about 1/2" to 3/4" and "merge" them into one another by spreading the strands a bit and inserting them into each other. A wrap of some small (20-22 ga.) copper wire around the joint will hold them for soldering. The trick is to melt a little solder on the iron tip and hold it to the joint and wait. The heat will transfer to the joint in a short time through the molten contact point. Add solder as needed until the joint is saturated. Clean flux away when cool and slide on a layer or two of heat shrink wrap available at Lowes or Home Depot etc. There are crimp-on butt splices available for the job or you could crimp and or solder some ring terminals to the ends and then "bolt" them together. Crimping any terminal or splice that large is tricky without the right crimping tools. If you buy a soldering iron large enough for the job instead of a crimping tool you'll have an iron large enough to fix the radiator in your wife's car. --Bonus in my book! John P. Marzluf Columbus, Ohio Outback, (out back in the garage) ________________________________________________________________________________
Date: Sep 17, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: FW: Splice 6AWG Wire
> > >In a message dated 9/17/2005 7:48:16 P.M. Eastern Standard Time, >pete.howell@gecko-group.com writes: > >I have one of the in-line maxifuse holders wirth 6AWG wire. One lead is not >long enough. How is the best way to splice in a longer piece of 6AWG? John. Great answer. I was going to suggest the same thing. The size of the soldering tool may not have to be a 'hog' . . . First, you'll find that 6AWG aircraft wire is made up of 137 total strands 27AWG wire that is layered over a center "rope" of 19 strands. Each layer is twisted in a direction opposite that of the adjacent layer. You won't be able to simply fan and push strands of wires together. The fuseholder is automotive and may be as few as seven strands but probably more. Step 1 is to "cone out" all strands of both wires and use needle nose plier to reasonably straighten each strand. The strip-length for each wire is about 1". Now, overlap about 3/4" of one wire's strands into the other and work down the fanned out cone of wires on both sides toward a smooth, intermeshed cylinder of all strands. I recommend a piece of the smallest safety wire you have. You want a fixture wire that does not solder into the finished joint. Monel or stainless wire will hold things together while you solder and remain free of joint so it can be removed later. Start right at insulation on one wire and put a couple of turns of safety wire on in close pitch. Then move wrapping over to first-second third of overlap for a couple of turns. Next put a couple turns at second-third third of overlap. Finish up with a few turns outside the overlap on the other wire. You want gaps between the five fixture-wraps to feed solder into the joint and observe wetting of the strands. Now, if you have a really efficient iron (like the Metcal series) you can easily solder this size wire with the 35 watt tool. Alternatively, check out your local Home Depot or Lowes for a Bernz-O-Matic ST100T butane torch. They sell for about $10 and you'll need a $4 fuel cannister. http://tools.batauto.com/index.php?crn=234&rn=1123&action=show_detail&PHPSESSID=cdea544011802efadd1901040779d172 This is a very hi quality alternative to a pencil butane torch found in hobby shops and Harbor Freight. I give these BernzOMatic torches away at my weekend seminars. Use some 60/40 or 63/37 electronic solder to join strands of the wires. Oh, yes . . . be sure to put 1 or 2 chunks of heatshrink on the pigtails BEFORE you begin all this. It may be VERY hard to put it on later! After the joint cools, peel the safety wire off, check for little sharp "tits" on the wire or possible exposed strand ends that might puncture the heatshrink. Cover your finished and smoothed joint with a couple layers of heatshrink and you're done. I'll go get the stuff to do a comic book on this tomorrow sometime. Bob . . . >Hello Pete, > >There are a few ways to splice wires of that size. My choice would be to >solder them but, most guys would not have a soldering iron large enough >for the >job. You would need an iron with a chisel tip and about 120 Watts of heat. >The Weller SP120 would be a good choice. Strip the insulation off the wires >about 1/2" to 3/4" and "merge" them into one another by spreading the >strands a bit and inserting them into each other. A wrap of some small >(20-22 ga.) >copper wire around the joint will hold them for soldering. > >The trick is to melt a little solder on the iron tip and hold it to the >joint and wait. The heat will transfer to the joint in a short >time through the >molten contact point. Add solder as needed until the joint is saturated. >Clean flux away when cool and slide on a layer or two of heat shrink wrap >available at Lowes or Home Depot etc. > >There are crimp-on butt splices available for the job or you could crimp and >or solder some ring terminals to the ends and then "bolt" them together. >Crimping any terminal or splice that large is tricky without the right >crimping >tools. > >If you buy a soldering iron large enough for the job instead of a crimping >tool you'll have an iron large enough to fix the radiator in your >wife's car. >--Bonus in my book! > >John P. Marzluf >Columbus, Ohio >Outback, (out back in the garage) > > >-- > > >-- incoming mail is certified Virus Free. Bob . . . -------------------------------------------------------- < Throughout history, poverty is the normal condition > < of man. Advances which permit this norm to be > < exceeded -- here and there, now and then -- are the > < work of an extremely small minority, frequently > < despised, often condemned, and almost always opposed > < by all right-thinking people. Whenever this tiny > < minority is kept from creating, or (as sometimes > < happens) is driven out of a society, the people > < then slip back into abject poverty. > < > < This is known as "bad luck". > < -Lazarus Long- > <------------------------------------------------------> http://www.aeroelectric.com ________________________________________________________________________________
Date: Sep 17, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: RE: Breaker Interrupt Rating
> >Bob; > >I DID post (to this list) the exact specific technical parts etc. details of >my test and you seemed never recognize that fact. Forgive me. I WAS watching for such information since I was the one who requested it. Can you give me an approximate date or repeat your post. I'll so search the archives if necessary. Give me one part number you cited. It will make the search so much faster. > That I used words and not >a schematic is not important in this case as a schematic is not needed with >such a simple circuit. I did use a different wiring diagram (of your >schematic) to duplicate what is in my aircraft however. Then is it a fair presumption that as an skilled and articulate engineer that you've documented that portion of your system's wiring in a manner that can be scanned and shared? >But you cannot duplicate my results (as I under stand what you mean by >duplicate) unless you use the exact same parts I used. The same identical >part, not a part of the same brand and part number is required in this case >because of the very wide variation in the parts tolerances. Absolutely! I've never done a test report without identifying or at least making full disclosure of parts used, techniques, measurements, etc. I'd be pleased for you to take the parts I used in http://www.aeroelectric.com/articles/Crowbar_OV_Protection/DC_Power_System_Dynamics_C.pdf and show me how I mis-read or mis-interpreted data at the risk of making a bad deduction. You seem to accept the test results I posted but counter with "that's not what I got with MY test." Fine . . . tell us how you did it. >Only if a worst case analysis is properly done and the range of test results >is determined can any test be duplicated by another using different physical >parts of the same part number. The part to part variation in most cases and >clearly in this case is simply too large. I'm mystified as to this part-to-part variation you cite. >Crow bar short circuit currents can vary from well under 100 amps to over >400 amps depending on the parts used and the wiring diagram used to >implement the same schematic. I don't doubt it . . . but I'm still trying to visualize the 400A case. >Thus any test that results in a current from around 100 amps to around 400 >amps is in fact a duplication of another's test results in this case. > >Where there are small parts variations the duplicated test results will be >much closer but NEVER identical. You don't have to sell me on stacked up variability and test tolerances . . . I've been doing this since high school physics. >For example the following is true: > >#1 CB ratings vary widely in resistance and trip time, in fact, close to a >10 -1 variation. between parts of the same brand and parts from other >brands. Nothing strange about My CB having an internal resistance 1/10 of >the one you used. CB internal resistance can and does vary from approx 0.003 >to over 0.030 ohms; a 10-1 variation This I really need to see. What brand and part number exhibits such variability? The problem I'm having is that trip characteristics are an I(squared)*T event that depends on heat generated within the current sensing part of the breaker. ANY breaker that shows a 10:1 variability in resistance should be expected to show a similar variability in trip characteristics. There are no manufacturers I work with that would offer me such a product. Gee, a 5A breaker that can open anywhere between 2.5 and 25 amps! >#2 Battery internal resistance also varies again as much as 10-1 depending >on the battery brand and ratings. My batteries have 1/5 to 1/10 the internal >resistance of your battery. But then I do not use the Panasonic brand or >similar types.I do use a very popular PS625 (dual at that) battery with much >higher specifications in most important parameters. Not that the Panasonic >is bad but its not nearly the same in several (important to me) electrical >specifications. As I've repeated many times, I don't care if your battery is ZERO ohms. There's a rational, recommended installation technique for using my products where the MAJOR contributor of loop resistance is wiring, a minor contributor is circuit breaker heater resistance with so small an amount coming from the battery and fatwires that they can be ignored. Nonetheless, I'm intently interested in your .0035 to .0017 ohm battery. Do I recall that you're building a Subaru powered two-place? Batteries I can find with this level of performance start out at 60 pounds and go up from there. I presume you ARE planning on carrying passengers in this airplane . . . >#3 My wiring was an exact duplicate of what I have in my aircraft and is a >fraction of what you had in your test. My wiring is less that 1/2 the >internal resistance of your test wiring. Very good. The systems I recommend and illustrate in the Z-figures are rooted in practices found in the vast majority of Certified and OBAM iron. Of course one should not toss away lots of performance in wire drops and soggy batteries . . . but then, wiring everything with 00 gage and installing batteries that would crank a Detroit Diesel in a N. Dakota winter has some seriously diminished returns on overall system design. If you have 1/2 the loop resistance illustrated in my experiments, you must have a rational for increased battery and wire sizes at the sacrifice of useful load. We'd be interested in understanding the design goals by which you arrived at this exceedingly low loss system. >I measures the battery internal resistance as well as the CB and wiring >resistances before and after the testing series. > >The same CB was used in the simulated worst case test where the current was >700 amps and there were at least 50 tests of the real circuit where the >current was 400 amps. No degrading of any part including the SCR in your >crow bar circuit which was over stressed several times its max rating. Then no doubt you can tell me what the battery part number was, what circuit breaker was used, what SCR was used, what diameters and lengths of wires were used . . . I'll pay you my consulting fee for the time it takes you to type that data into a posting here on the list. >This overstressing and lack of damage does not mean its a good design idea >and more importantly does not mean that all CB's will survive with no >damage. > >In this case the main short current drivers are the Battery, CB and wiring >resistances. > >That alone suggests that 400 amps is easy to achieve as the circuit >resistance to get 400 amp vs. 130 amps only needs to decrease to 1/3 or so. > >Bottom line: I had 6 EXPERT, experienced, real electrical engineers review >what I have done and ALL agreed with my test setup and suggested 400 amps >was not the max current possible as I had not used the worst case analysis >parts. Then may we expect to see their names on the byline for a detailed report? As long you've opened the door to name dropping, I'll claim real signatures of dozens of folks representing systems designers, DERs, program managers, test pilots and test technicians who executed paperwork certifying this system on Mooney, Piper, Beech, Cessna and Cirrus aircraft. This is over and above thousands of OBAM aircraft customers who seem to be getting satisfactory performance from their purchases. For the moment, I have no greater assurances of the existence of your six "experts" than I do of the half dozen or so of my customers you claim were ALL having nuisance trip problems NONE of whom would call me for assistance and ALL of which declined an opportunity to exercise my well published 100% satisfaction or money back guarantee. >I had hoped this issue had gone away months ago as we will never agree. I >only post here when I feel my comments are being misquoted to the extreme. >Seems that will never end and frankly I am saddened that it seems to >continue. The List is a classroom. Folks will always be asking about these issues and as one of several teachers on the list, I have a duty to sort myth, old mechanic's tales, and bad science from fact as I understand it. If you want this discussion to end, then carry out your past threats never to post again. If you have facts to dispute, then be a teacher and publish counter balancing facts. Either is fine with me . . . but don't expect me not to continue to counter rumors, yours or anyone else's. I'm sure Greg Richter is fond of telling tales over a beer about how he crossed swords with that wild-eyed guy in Wichita and the telling probably gets better with each pitcher full. He too was amazingly reluctant to answering a single direct question. If you're ready to mark me off as hopeless, you're welcome to bow out . . . I've even offered $cash$ rewards for simple answers to specific questions. It would be worth it to me. My exorbitant consulting rate at the moment is $75/hour. If you could save me a hour of time digging around trying to figure out exactly how you arrive at some of your mystifying numbers, then I'd be money ahead to pay you cash for the data. I'd rather use the hour to add value to someone's airplane as opposed to sorting your jigsaw puzzle with many missing pieces. How about filling in your version of the pieces in the first figure on page 2 of the paper cited above and show us all how you generated a 400A crowbar event? >The basic issue of OVP crow bar short to open a CB is the real discussion >where you believe its a good approach and I disagree is the fundamental >issue and the short current is a distraction. Hmmm . . . at least it's devolved to a 'distraction' . . . there have been times past when the crowbar event could be expected to cause all manner of bad day including in-flight reset of EFIS systems and engine stoppage. If you have a better approach, you're most welcome to join the rest of us in the free marketplace. >Please do not snip this email as it tends to put my comments out of context >and change the meaning/intent of my comment. > >Better yet simply do not reply and we can both put this stupid debate to >rest and get on with productive discussions. If it's stupid, it's only because you're not debating. Any high school debate teacher would have tossed you out of this classroom years ago. My physics teacher would have tossed you out of his class too. I saw him do it to a kid that "dry labbed" an important assignment. This is not a classroom on debate, it's a classroom of simple ideas and physics as they relate to building the best airplanes to have ever flown. Show us your setup, show us your work and show us your data. Okay, how's this for a productive topic: How do you propose we offer a means by which an OBAM aircraft community a means for installing an internally regulated alternator such that its operation transparent to the paradigm under which generators and alternators have been operated on aircraft since day-one to wit: (1) Absolute pilot control over engine drive power source. (2) Failure and hazard free switching of the engine driven power source at any time and under any conditions. . . . of course, answers to the above will offer the OBAM aircraft builder a means by which any attractive OV protection philosophy can be added assuming he/she so desires. These are the questions I thought you were going to answer when you went off to do the tests over a year ago. Presumably you have the data necessary to make considered recommendations. We're all ears. Bob . . . ________________________________________________________________________________
Date: Sep 17, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: magneto timing buzz box
> > >Take a look at the $25 kit from www.MagnetoTimer.com >and see if that meets your needs. > >I've built two - it's a fun little soldering project, all the parts >are included and identified (taped to the instruction sheet). >About an hour of fitting & soldering and you've got a nice tool. > >The leads coil up and stow inside the open front of the plastic case. > >Greg If you have done two of them, I presume they work as advertised. This looks like one hell-of-a bargain. He must be selling a bunch to get his costs down at this selling price. This looks like the most elegant alternative to the AC impedance measuring device. Ron's approach with a milliohm-sensitive ohmmeter is an elegant, non-specialized approach in the DC measurement world too. Bob . . . ________________________________________________________________________________
Date: Sep 17, 2005
From: rv-9a-online <rv-9a-online(at)telus.net>
Subject: Re: FW: Splice 6AWG Wire
Pete, I would crimp a ring terminal on both ends and secure with a bolt. Wrap the whole thing up with silicone fusion tape. It will look like a pig in a python, but it should work. If you want it to be more secure, mount a similiar type splice to a UMHW block that is counterbored for the bolt, and mount the UMHW block with screws to the structure somewhere. If you don't have any UMHW, try any kind of rigid plastic or plexiglass. If you want to spend money, you can use a barrier terminal. Google "6 awg barrier terminal" and poke around the internet. Vern Little Pete Howell wrote: > > >I have one of the in-line maxifuse holders wirth 6AWG wire. One lead is not >long enough. How is the best way to splice in a longer piece of 6AWG? > > > > ________________________________________________________________________________
Date: Sep 18, 2005
From: Scott Derrick <scott(at)tnstaafl.net>
Subject: Re: magneto timing buzz box
Greg, thanks for the tip. My orders in for one... Scott Greg Campbell wrote: > >Take a look at the $25 kit from www.MagnetoTimer.com >and see if that meets your needs. > >I've built two - it's a fun little soldering project, all the parts >are included and identified (taped to the instruction sheet). >About an hour of fitting & soldering and you've got a nice tool. > >The leads coil up and stow inside the open front of the plastic case. > >Greg > > >. > > > ________________________________________________________________________________
Date: Sep 18, 2005
From: "Dave Morris \"BigD\"" <BigD(at)DaveMorris.com>
Subject: Re: FW: Splice 6AWG Wire
I used this technique to put ring terminals on 2 and 4 gauge wire. Works really well and takes about 5 seconds to heat it up. Dave Morris At 11:38 PM 9/17/2005, you wrote: > > > Now, if you have a really efficient iron (like the Metcal > series) you can easily solder this size wire with the 35 > watt tool. Alternatively, check out your local Home Depot > or Lowes for a Bernz-O-Matic ST100T butane torch. They > sell for about $10 and you'll need a $4 fuel cannister. > >http://tools.batauto.com/index.php?crn=234&rn=1123&action=show_detail&PHPSESSID=cdea544011802efadd1901040779d172 > > This is a very hi quality alternative to a pencil butane > torch found in hobby shops and Harbor Freight. I give > these BernzOMatic torches away at my weekend seminars. > > Use some 60/40 or 63/37 electronic solder to join strands > of the wires. Oh, yes . . . be sure to put 1 or 2 chunks > of heatshrink on the pigtails BEFORE you begin all this. > It may be VERY hard to put it on later! ________________________________________________________________________________
Date: Sep 18, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: magneto timing buzz box
> >Greg, > >thanks for the tip. My orders in for one... > >Scott Let me know your impressions of its usefulness . . . Bob . . . ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: RE load dump
Date: Sep 18, 2005
I consider the entire subject (crow bar currents) closed. I feel no need to continue based on your statements as its simply not worth my time to reply. Until my comments are accepted as fact and we can get past that and deal with the real issues the ridicule of my test results clearly says it was a mistake to ever start this in the beginning. Further the snide remarks from others does not help clear the air. On the load dump test: Here is a quick review of the results 1. Eric and I gave up and I declined to publish in the detail you seem to need. Simply not worth the time that would be needed to reply to your disbelief or need to duplicate tests that may require the exact parts (as part type is not enough) and this thread is proof of that. 2. The testing showed that there was NO problem with normal load dump as long as there was a battery connected to the system and NO OVP of your design connected (see below). 3. We also investigated the case of NO battery as many want to have that as a backup mode of flight. As I have personally seen 3 aircraft batteries fail open in flight (two concord RG type and one Gill), I felt it was worth including this in the testing. Your OVP module failed 100% of the time (in even small load dumps) but that was expected as it clearly was not designed to support that mode of operation (no battery). Adding a 25,000 MFD capacitor reduced the alternator ripple voltage but did not control the small load sumps and your OVP continued to trip 100% of the time, again not unexpected as the trip time was far too short to allow even a cap filtered load dump to pass. Here transorbs worked well to clamp the peak load dump voltage spike. Adjusting the OPV trip voltage higher to allow for transorb clamping resolves the tripping issue with the OVP 3. The OVP module you offer as plans was built up on a 1" x 1.5" pcb and two made. Both had false trips 100% of the time when a large load was switched ON. This led to a simple design review of this OVP and we discovered there were two design errors that made the OVP sensitive to simple changes in bus voltage etc. One has been recently posted and the other is a sensitivity to contact bounce and the fast trip time. Besides the OVP design issues the contactor applying the load has contact bounce that was triggering the OVP. There was no further effort on your OVP design (by us) as the design concept was very old and there are simple IC parts available that made a simple modern design with adjustable trip times off the shelf. Why try to fix something that is decades behind the current technology?? as the new design had built-in production against false triggering it was a win win solution. Further there is the simple opening of the contactor coil and Zero crowbar current as the design does not use a crowbar. The solution we proposed was to be sure the OVP trip time was much longer than relay/contactor contact bounce (actually longer than a expected load dump event). Contact bounce on load removal also caused problems. I did post a reference from a major relay manufacturer that contact bounce on contact opening WITH a diode across the coil was very bad idea and not only was there contact bounce on opening there was the possibility of contact welding on opening. Use of transorbs clipped the load dump transient and everything worked right thru the transient even with no battery on line. 4. There was widespread (reported by Vans, and several builders who directly contacted me off list) false tripping by the OVP and resulting alternator failure where the alternator was internally regulated and the "B" lead contactor was the common type that not only bounced on opening (due largely to the recommended diode) and also to the resulting load dump peak voltage that greatly exceeded the contactor maximum contact voltage rating. Heavy contact arcing was documented. This resulted in the recommended Kilovac contactor as its the only reasonable cost contactor with the proper ratings and there is no coil diode to cause problems on contact opening. 5. We then had a system design solution with a no false tripping OVP and a "B" lead contactor that did not damage the alternator. Eric is now selling the OVP design and has on occasion the Kilovac contactors that allow safe "B" lead opening. 6. I further investigated "rebuilt alternators" and found the term misleading. Only parts that were failed were replaced. The term should be repaired not rebuilt. The popular ND 55 amp alternator has been around for more than 20 years and many have been rebuilt several times. Who knows the quality of the current regulator? Thus only brand NEW alternators should be used. 7. Replacing the fast trip and occasional false tripping OVP with a modern design eliminates false trips. Eliminating the Crow bar eliminated the hi current and its side affects (see below). If used, the proper "B" lead contactor will prevent alternator damage often caused by the improperly used common contactor that is not designed or specified for this specific application and further hindered with the incorrect application of a diode across the coil against major manufacturers worked wide. In fact the common diode across the coil is not recommended anywhere any time by relay manufacturers. That its very common in use does not mean its a good approach, It simply means that most engineers are lazy and copy what has been done in the past rather that research what is recommended so the diode persists even with its being the last and worst choice in a list of options. IN conclusion the test results showed that much of the alternator failures were the direct result of the OVP design and associated contactor. Its not known if poor alternator regulators were a factor but even good ones are very likely to be damaged by the current design contactor used. Its clear that the contactor used has a very high potential of regulator damage and when coupled with a false trip prone (in some as yet defined aircraft wiring or operations) is the root cause. Use a modern non-crowbar OVP design and a contactor designed for the application resolved most of the problem. Its not possible to ignore the likely hood of lesser quality regulators in rebuilt alternators so only new alternators should be used. With the demonstrated extremely high reliability of the ND brand of internally regulated alternators is very questionable that there is a need for more that having the OVP simply remove the voltage to "I" lead (the field control lead) that shuts down the alternator. I have been unable to find any repair shop that has ever heard of an ND alternator having uncontrolled runaway failure. No output or hi output that is still controllable with the "I" lead. Prop bolts or crank shafts are more likely to fail and yes I have a report of a light twin having both engines prop bolts failing. Now for the hi current related problems. In an steel tube reinforced cockpit like the Glastar (or other production aircraft) its been proven that even the normal bus loads can magnetize the tube structure and cause compass errors of as high as 30 degrees. I previously referenced a manufacturers mandatory service bulletin that addressed this issue and also discussed with a owner of that type aircraft that had it happen to him. He is highly educated and a long time IA. The compass in question was a suspended well above the affected tubes This tells me that even 50 amp buss circuits need special wire routing and forget the 100+++ current transients from a crow bar. This alone says if you have a steel tubular cabin be careful and forget a crow bar approach. In any event this is my last word on either subject even if the misquoting etc continues. Paul ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> Subject: Re: AeroElectric-List: RE: Breaker Interrupt Rating > > > >> >> >>Bob; >> >>I DID post (to this list) the exact specific technical parts etc. details >>of >>my test and you seemed never recognize that fact. > > Forgive me. I WAS watching for such information since I was the > one who requested it. Can you give me an approximate date or repeat > your post. I'll so search the archives if necessary. Give me one > part number you cited. It will make the search so much faster. > >> That I used words and not >>a schematic is not important in this case as a schematic is not needed >>with >>such a simple circuit. I did use a different wiring diagram (of your >>schematic) to duplicate what is in my aircraft however. > > Then is it a fair presumption that as an skilled and articulate > engineer that you've documented that portion of your system's > wiring in a manner that can be scanned and shared? > > >>But you cannot duplicate my results (as I under stand what you mean by >>duplicate) unless you use the exact same parts I used. The same identical >>part, not a part of the same brand and part number is required in this >>case >>because of the very wide variation in the parts tolerances. > > Absolutely! I've never done a test report without identifying > or at least making full disclosure of parts used, techniques, > measurements, etc. I'd be pleased for you to take the parts I > used in > > http://www.aeroelectric.com/articles/Crowbar_OV_Protection/DC_Power_System_Dynamics_C.pdf > > and show me how I mis-read or mis-interpreted data at the risk > of making a bad deduction. You seem to accept the test results > I posted but counter with "that's not what I got with MY test." > Fine . . . tell us how you did it. > > >>Only if a worst case analysis is properly done and the range of test >>results >>is determined can any test be duplicated by another using different >>physical >>parts of the same part number. The part to part variation in most cases >>and >>clearly in this case is simply too large. > > I'm mystified as to this part-to-part variation you cite. > >>Crow bar short circuit currents can vary from well under 100 amps to over >>400 amps depending on the parts used and the wiring diagram used to >>implement the same schematic. > > I don't doubt it . . . but I'm still trying to visualize the > 400A case. > >>Thus any test that results in a current from around 100 amps to around 400 >>amps is in fact a duplication of another's test results in this case. >> >>Where there are small parts variations the duplicated test results will be >>much closer but NEVER identical. > > You don't have to sell me on stacked up variability and test > tolerances . . . I've been doing this since high school > physics. > > >>For example the following is true: >> >>#1 CB ratings vary widely in resistance and trip time, in fact, close to >>a >>10 -1 variation. between parts of the same brand and parts from other >>brands. Nothing strange about My CB having an internal resistance 1/10 of >>the one you used. CB internal resistance can and does vary from approx >>0.003 >>to over 0.030 ohms; a 10-1 variation > > This I really need to see. What brand and part number exhibits > such variability? The problem I'm having is that trip characteristics > are an I(squared)*T event that depends on heat generated within > the current sensing part of the breaker. ANY breaker that shows > a 10:1 variability in resistance should be expected to show > a similar variability in trip characteristics. There are no > manufacturers I work with that would offer me such a product. > > Gee, a 5A breaker that can open anywhere between 2.5 and 25 amps! > > >>#2 Battery internal resistance also varies again as much as 10-1 depending >>on the battery brand and ratings. My batteries have 1/5 to 1/10 the >>internal >>resistance of your battery. But then I do not use the Panasonic brand or >>similar types.I do use a very popular PS625 (dual at that) battery with >>much >>higher specifications in most important parameters. Not that the Panasonic >>is bad but its not nearly the same in several (important to me) electrical >>specifications. > > As I've repeated many times, I don't care if your battery > is ZERO ohms. There's a rational, recommended installation > technique for using my products where the MAJOR contributor > of loop resistance is wiring, a minor contributor is circuit > breaker heater resistance with so small an amount coming from > the battery and fatwires that they can be ignored. Nonetheless, > I'm intently interested in your .0035 to .0017 ohm battery. > Do I recall that you're building a Subaru powered two-place? > Batteries I can find with this level of performance start out > at 60 pounds and go up from there. I presume you ARE planning > on carrying passengers in this airplane . . . > > >>#3 My wiring was an exact duplicate of what I have in my aircraft and is a >>fraction of what you had in your test. My wiring is less that 1/2 the >>internal resistance of your test wiring. > > Very good. The systems I recommend and illustrate in the Z-figures > are rooted in practices found in the vast majority of Certified > and OBAM iron. Of course one should not toss away lots of > performance in wire drops and soggy batteries . . . but then, > wiring everything with 00 gage and installing batteries that > would crank a Detroit Diesel in a N. Dakota winter has some > seriously diminished returns on overall system design. If you > have 1/2 the loop resistance illustrated in my experiments, you > must have a rational for increased battery and wire sizes at the > sacrifice of useful load. We'd be interested in understanding > the design goals by which you arrived at this exceedingly low > loss system. > >>I measures the battery internal resistance as well as the CB and wiring >>resistances before and after the testing series. >> >>The same CB was used in the simulated worst case test where the current >>was >>700 amps and there were at least 50 tests of the real circuit where the >>current was 400 amps. No degrading of any part including the SCR in your >>crow bar circuit which was over stressed several times its max rating. > > Then no doubt you can tell me what the battery part number was, what > circuit > breaker was used, what SCR was used, what diameters and lengths of > wires were used . . . I'll pay you my consulting fee for the time > it takes you to type that data into a posting here on the list. > > >>This overstressing and lack of damage does not mean its a good design idea >>and more importantly does not mean that all CB's will survive with no >>damage. >> >>In this case the main short current drivers are the Battery, CB and wiring >>resistances. >> >>That alone suggests that 400 amps is easy to achieve as the circuit >>resistance to get 400 amp vs. 130 amps only needs to decrease to 1/3 or >>so. >> >>Bottom line: I had 6 EXPERT, experienced, real electrical engineers >>review >>what I have done and ALL agreed with my test setup and suggested 400 amps >>was not the max current possible as I had not used the worst case analysis >>parts. > > Then may we expect to see their names on the byline for a > detailed report? As long you've opened the door to name dropping, > I'll claim real signatures of dozens of folks representing systems > designers, DERs, program managers, test pilots and test > technicians who executed paperwork certifying this system on > Mooney, Piper, Beech, Cessna and Cirrus aircraft. This is over > and above thousands of OBAM aircraft customers who seem to be getting > satisfactory performance from their purchases. > > For the moment, I have no greater assurances of the existence > of your six "experts" than I do of the half dozen or so of > my customers you claim were ALL having nuisance trip problems > NONE of whom would call me for assistance and ALL of which declined > an opportunity to exercise my well published 100% satisfaction > or money back guarantee. > >>I had hoped this issue had gone away months ago as we will never agree. I >>only post here when I feel my comments are being misquoted to the extreme. >>Seems that will never end and frankly I am saddened that it seems to >>continue. > > The List is a classroom. Folks will always be asking about these > issues and as one of several teachers on the list, I have a duty > to sort myth, old mechanic's tales, and bad science from > fact as I understand it. If you want this discussion to end, then > carry out your past threats never to post again. If you have > facts to dispute, then be a teacher and publish counter balancing > facts. Either is fine with me . . . but don't expect me not > to continue to counter rumors, yours or anyone else's. I'm sure > Greg Richter is fond of telling tales over a beer about how > he crossed swords with that wild-eyed guy in Wichita and the > telling probably gets better with each pitcher full. He too > was amazingly reluctant to answering a single direct question. > If you're ready to mark me off as hopeless, you're welcome to > bow out . . . > > I've even offered $cash$ rewards for simple answers to > specific questions. It would be worth it to me. My exorbitant > consulting rate at the moment is $75/hour. If you could save > me a hour of time digging around trying to figure out exactly > how you arrive at some of your mystifying numbers, then > I'd be money ahead to pay you cash for the data. I'd rather > use the hour to add value to someone's airplane as opposed to > sorting your jigsaw puzzle with many missing pieces. How about > filling in your version of the pieces in the first figure on > page 2 of the paper cited above and show us all how you > generated a 400A crowbar event? > > >>The basic issue of OVP crow bar short to open a CB is the real discussion >>where you believe its a good approach and I disagree is the fundamental >>issue and the short current is a distraction. > > Hmmm . . . at least it's devolved to a 'distraction' . . . there have > been times past when the crowbar event could be expected to cause > all manner of bad day including in-flight reset of EFIS systems > and engine stoppage. If you have a better approach, you're > most welcome to join the rest of us in the free marketplace. > >>Please do not snip this email as it tends to put my comments out of >>context >>and change the meaning/intent of my comment. >> >>Better yet simply do not reply and we can both put this stupid debate to >>rest and get on with productive discussions. > > If it's stupid, it's only because you're not debating. Any high school > debate teacher would have tossed you out of this classroom years ago. > My physics teacher would have tossed you out of his class too. I saw > him do it to a kid that "dry labbed" an important assignment. This is > not a classroom on debate, it's a classroom of simple ideas and physics > as they relate to building the best airplanes to have ever flown. > Show us your setup, show us your work and show us your data. > > Okay, how's this for a productive topic: > > How do you propose we offer a means by which an OBAM aircraft > community a means for installing an internally regulated alternator > such that its operation transparent to the paradigm under which > generators and alternators have been operated on aircraft since > day-one to wit: > > (1) Absolute pilot control over engine drive power source. > > (2) Failure and hazard free switching of the engine driven power > source at any time and under any conditions. > > . . . of course, answers to the above will offer the OBAM aircraft > builder a means by which any attractive OV protection philosophy > can be added assuming he/she so desires. These are the questions I > thought > you were going to answer when you went off to do the tests over a > year ago. Presumably you have the data necessary to make considered > recommendations. We're all ears. > > Bob . . . > > > ________________________________________________________________________________
Date: Sep 18, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: RE load dump
> >I consider the entire subject (crow bar currents) closed. I feel no need to >continue based on your statements as its simply not worth my time to reply. >Until my comments are accepted as fact and we can get past that and deal >with the real issues the ridicule of my test results clearly says it was a >mistake to ever start this in the beginning. Further the snide remarks from >others does not help clear the air. I disagree. It was a VERY valuable discussion. One gains confidence in teachers based on a history of an individual's ability to impart understanding. The name behind the words is immaterial when understanding is achieved . . . the only time a name is important is when it identifies a source of words where understanding is difficult if not impossible to achieve. E.g. I didn't have to try many cups of McDonalds coffee to know that it was fruitless to expect it to be any better in another establishment with the same sign out front. >On the load dump test: > >Here is a quick review of the results > >1. Eric and I gave up and I declined to publish in the detail you seem to >need. Simply not worth the time that would be needed to reply to your >disbelief or need to duplicate tests that may require the exact parts (as >part type is not enough) and this thread is proof of that. > >2. The testing showed that there was NO problem with normal load dump as >long as there was a battery connected to the system and NO OVP of your >design connected (see below). This was predictable, easily explained and understood . . . >3. We also investigated the case of NO battery as many want to have that as >a backup mode of flight. As I have personally seen 3 aircraft batteries fail >open in flight (two concord RG type and one Gill), I felt it was worth >including this in the testing. Agreed . . . >Your OVP module failed 100% of the time (in >even small load dumps) but that was expected as it clearly was not designed >to support that mode of operation (no battery). You got that right. This was the first time in history of aviation as far as I've studied it that no-battery operation was brought forth as a design goal with alternators. Generators are very friendly in the no-battery mode. We do it all the time in today's fleet of bizjets. Had you asked me about performance of my product before you mis-applied it, I would have predicted the results you demonstrated. Had you asked for a modified product to function under a new deign goal, I would have been pleased to try. >Adding a 25,000 MFD >capacitor reduced the alternator ripple voltage but did not control the >small load sumps and your OVP continued to trip 100% of the time, again not >unexpected as the trip time was far too short to allow even a cap filtered >load dump to pass. Yup, water runs down hill and the sun comes up in the east . . . > Here transorbs worked well to clamp the peak load dump >voltage spike. Adjusting the OPV trip voltage higher to allow for transorb >clamping resolves the tripping issue with the OVP Or . . . one could increase the trip time-constant such that the integrated waveform of the dump event does not add up to a value greater than trip point . . . it's a new paradigm that needed to be explored, values deduced, and goals established. >3. The OVP module you offer as plans was built up on a 1" x 1.5" pcb and two >made. Both had false trips 100% of the time when a large load was switched >ON. This led to a simple design review of this OVP and we discovered there >were two design errors that made the OVP sensitive to simple changes in bus >voltage etc. One has been recently posted and the other is a sensitivity to >contact bounce and the fast trip time. Besides the OVP design issues the >contactor applying the load has contact bounce that was triggering the OVP. Gee Paul, I thought you were going to participate in a new discussion about energies and dynamics of the load-dump event as presented by alternators you had the facilities to test. All you've done is moved off on another whack at the crowbar OVP system which was originally designed to meet different goals and modified as field experience suggested. You never once asked me to participate in the gathering and analysis of data nor in the deduction of solutions to meet your desires . . .which is the core of my life's work as an engineer. Instead you simply threw "rocks". You got really stirred up when instead of cowering and capitulating under your barrage, I fielded the suckers and of the community know them as such. >There was no further effort on your OVP design (by us) as the design concept >was very old and there are simple IC parts available that made a simple >modern design with adjustable trip times off the shelf. Why try to fix >something that is decades behind the current technology?? as the new design >had built-in production against false triggering it was a win win solution. >Further there is the simple opening of the contactor coil and Zero crowbar >current as the design does not use a crowbar. This was never an argument. Use any OVP design philosophy that floats your boat. The fact that you're asking something I did to meet your new, unspecified and unanswered design goals after I've designed and delivered the product to other goals is truly astounding. If you use a wrench to drive nails and then complain to the wrench supplier about the problems you're having, the speciousness of your comments become obvious. >The solution we proposed was to be sure the OVP trip time was much longer >than relay/contactor contact bounce (actually longer than a expected load >dump event). Contact bounce on load removal also caused problems. I did post >a reference from a major relay manufacturer that contact bounce on contact >opening WITH a diode across the coil was very bad idea and not only was >there contact bounce on opening there was the possibility of contact welding >on opening. This is BS and I'm working on the paper and test report to show why. But we can save that 'discussion' for another time. > Use of transorbs clipped the load dump transient and everything >worked right thru the transient even with no battery on line. EXCELLENT! Now, how long was the load dump event? What was its amplitude? How many Joules of energy were dumped into the transorbs. What RPM were you running the alternator. Would the transorbs you selected be reasonably expected to handle a moderately loaded alternator running at over 10,000 rpm? >4. There was widespread (reported by Vans, and several builders who directly >contacted me off list) false tripping by the OVP and resulting alternator >failure where the alternator was internally regulated and the "B" lead >contactor was the common type that not only bounced on opening (due largely >to the recommended diode) and also to the resulting load dump peak voltage >that greatly exceeded the contactor maximum contact voltage rating. Heavy >contact arcing was documented. This resulted in the recommended Kilovac >contactor as its the only reasonable cost contactor with the proper ratings >and there is no coil diode to cause problems on contact opening. You've stirred a whole lot of ingredients into this paragraph. First, vulnerability of the alternator to damage was a direct function of adding a means of positive control. It had to do with adding a b-lead contactor. It didn't matter what contactor was used, whether or not a diode was present across the contactor or whether OVP was present. The act of turning the alternator OFF for any reason while loaded was the proximate cause of damage to the alternator due to inability to withstand its own load-dump event. Yes, the contactor's switching limits needed review . . . yes, there were (you say but don't document) nuisance trip issues. I've seen hundreds of closure traces that demonstrate bounce in contacts of relays, breakers and switches as contacts come together. I've not seen contacts that are moving apart suddenly decided they're going the wrong direction and come back together for some period of time. Can you explain? Do you have any traces? What parts did this? What was the source of forcing moments that caused parts that were separating to reverse direction? >5. We then had a system design solution with a no false tripping OVP and a >"B" lead contactor that did not damage the alternator. Eric is now selling >the OVP design and has on occasion the Kilovac contactors that allow safe >"B" lead opening. Super! Are you telling me that this is your recommendation for absolute control of alternators? Gee, except for establishment and satisfaction of new design goals, this looks like Figure Z-24 that I published years ago . . . care to share any of the numbers that will help the rest of the world gain confidence in your recommendations? >6. I further investigated "rebuilt alternators" and found the term >misleading. Only parts that were failed were replaced. The term should be >repaired not rebuilt. The popular ND 55 amp alternator has been around for >more than 20 years and many have been rebuilt several times. Who knows the >quality of the current regulator? Thus only brand NEW alternators should be >used. A no brainer . . . if one accepts the limitations of selecting one's alternator from a small fraction of the total number of sources for alternators that MIGHT be perfectly okay under YOUR design goals. You've accused most engineers of being lazy, why did you stop short of crafting techniques that would allow the OBAM aircraft builder to apply ANY modern alternator "rebuilt" or not with the only risk being short service life? That's my design goal and yes, it will take some more work. The problem is time and equipment - not laziness. >7. Replacing the fast trip and occasional false tripping OVP with a modern >design (that discards Mil-STD-704 philosophies in place for decades and marches of to the beat of Paul's new drum . . .) >. . . eliminates false trips. Eliminating the Crow bar eliminated the hi >current and its side affects (see below). If used, the proper "B" lead >contactor will prevent alternator damage often caused by the improperly used >common contactor that is not designed or specified for this specific >application and further hindered with the incorrect application of a diode >across the coil against major manufacturers worked wide. In fact the common >diode across the coil is not recommended anywhere any time by relay >manufacturers. Yup, I've read the papers cited here on the list . . . and it didn't take 5 minutes at the bench to discount their value as drivers for our design goals. The amazing thing was that they were published by big names in the industry by folks with long lists of credentials. They took lots of good data, published some neat 'scope traces and then drew conclusions that could have been but were not directly measured . . . Others have read the papers and assumed that the stature and authority of the authors was sufficient to broadly apply their suppositions with almost religious fervor. Which underscores an observation I made years ago . . . just because one might have run a successful restaurant doesn't make them a good chef. > . . . That its very common in use does not mean its a good >approach, It simply means that most engineers are lazy and copy what has >been done in the past rather that research what is recommended so the diode >persists even with its being the last and worst choice in a list of options. You betcha. Did YOU bother to repeat their experiments and deduce for yourself the effects of diode-across-the-coil as we used it? This begs the question as to who is lazy here and who worships at the altars of Tyco-Amp, P&B, etc. >IN conclusion the test results showed that much of the alternator failures >were the direct result of the OVP design and associated contactor. Its not >known if poor alternator regulators were a factor but even good ones are >very likely to be damaged by the current design contactor used. Its clear >that the contactor used has a very high potential of regulator damage and >when coupled with a false trip prone (in some as yet defined aircraft wiring >or operations) is the root cause. Your train of thought for cause/effect is truly amazing . . . I'm going to save these threads for future reference. They'll be great teaching tools. >Use a modern non-crowbar OVP design and a contactor designed for the >application resolved most of the problem. Its not possible to ignore the >likely hood of lesser quality regulators in rebuilt alternators so only new >alternators should be used. > >With the demonstrated extremely high reliability of the ND brand of >internally regulated alternators is very questionable that there is a need >for more that having the OVP simply remove the voltage to "I" lead (the >field control lead) that shuts down the alternator. I have been unable to >find any repair shop that has ever heard of an ND alternator having >uncontrolled runaway failure. No output or hi output that is still >controllable with the "I" lead. Prop bolts or crank shafts are more likely >to fail and yes I have a report of a light twin having both engines prop >bolts failing. Okay, if I republish Z-24 then all I need to do is upgrade the contactor, recommend Eric's latest and greatest OVP product, and add a transorb (also Eric's product?). And finally, limit recommendations to brand new ND alternators? If Eric's OVP is in place is a builder on shaky ground by NOT using a new alternator . . . or even an ND product? Can you articulate the new design goals in the form of a white paper (the new Bible) that leads other designers down the path to Nirvana along with guidance as to the nature and magnitude of conditions to expect? (No, don't answer that. Let's go ahead and accept this as your "last word") >Now for the hi current related problems. > >In an steel tube reinforced cockpit like the Glastar (or other production >aircraft) its been proven that even the normal bus loads can magnetize the >tube structure and cause compass errors of as high as 30 degrees. I >previously referenced a manufacturers mandatory service bulletin that >addressed this issue and also discussed with a owner of that type aircraft >that had it happen to him. He is highly educated and a long time IA. The >compass in question was a suspended well above the affected tubes > >This tells me that even 50 amp buss circuits need special wire routing and >forget the 100+++ current transients from a crow bar. > >This alone says if you have a steel tubular cabin be careful and forget a >crow bar approach. This was the great and evil "side effect"? Gee Paul, wouldn't it be a good thing to simply NOT run high currents through the structure? Cranking the engine runs far more current (with higher inrushes) than a crowbar event will ever generate. The starter event happens every flight-cycle. The crowbar event is much smaller and may never happen. It's apparent to me that your primary driver in this exchange has been a vendetta against one who would have the audacity to question your autocracy in the non-dissemination of information combined with loads of un-substantiated advice. I don't believe this discussion had anything to do with science, the art of building reliable systems or the enthusiastic exchange of simple-ideas for which good teachers are noted. >In any event this is my last word on either subject even if the misquoting >etc continues. I have not snipped anything from your post so I cannot be accused of any mis-quotation. It's obvious that you have no appreciation for what it means to be a teacher or a responsible member of an engineering community. Since you failed to substantiate any of your allegations with data and cannot or will not answer any simple direct question, I must conclude that this being your "last word" on the matter is no loss to the OBAM aviation community. I look forward to spending time on more fruitful and honorable endeavors. As soon as I have time and access to the equipment, I'll repeat the tests you claim to have conducted and publish the results here and on my website. Please ignore them . . . there are plenty of sharp heads on the list who will help me refine my studies from which well considered design goals can be crafted and satisfied. I wish you well in your new job. Bob . . . ________________________________________________________________________________
From: "Paul McAllister" <paul.mcallister(at)qia.net>
Subject: Re: RE load dump
Date: Sep 18, 2005
Paul, At the risk of being accused of "snipping" your email, or offering snide remarks, this is truly a case of an expression we use in engineering shop where I work (a $15 billion /year company) It goes like, "In god we trust, everyone else bring data". Please share it, many of us may learn something new. With that said, this has been a truly enlightening discussion and the debate has taught me a lot (not only about engineering) Regards, Paul > > > I consider the entire subject (crow bar currents) closed. I feel no need > to > continue based on your statements as its simply not worth my time to > reply. > Until my comments are accepted as fact and we can get past that and deal > with the real issues the ridicule of my test results clearly says it was a > mistake to ever start this in the beginning. Further the snide remarks > from > others does not help clear the air. > ________________________________________________________________________________
From: "Steve Hunt" <stephen.hunt19(at)btinternet.com>
Subject: Re: RE load dump
Date: Sep 18, 2005
Hi Bob Wow! I just joined............ I want to ask you if you think it OK for me to proceed with my effort at hooking up my Vans 60 A int regulated alt as follows. (I am no engineer, have little electrical knowledge)I have a B& C cont rated contactor on the B lead which is switched by the second throw of my Batt/Alt sw (2-10). I have, as yet no crowbar. I intend to always start with alt switched off and stopping eng with alt switched on. I dont know how I got here as I have the lost the thread of the latest advice and am feeling confused. The loom all laid up, panel cut. I was ready to go and then got hopelessly lost trying to follow this. Whilst it may not be the best solution Bob, will this work? thanks in anticipation,Steve ----- From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> Subject: Re: AeroElectric-List: RE load dump > > > >> >> >>I consider the entire subject (crow bar currents) closed. I feel no need >>to >>continue based on your statements as its simply not worth my time to >>reply. >>Until my comments are accepted as fact and we can get past that and deal >>with the real issues the ridicule of my test results clearly says it was a >>mistake to ever start this in the beginning. Further the snide remarks >>from >>others does not help clear the air. > > I disagree. It was a VERY valuable discussion. One gains > confidence in teachers based on a history of an individual's > ability to impart understanding. The name behind the words is > immaterial when understanding is achieved . . . the only time a > name is important is when it identifies a source of words where > understanding is difficult if not impossible to achieve. E.g. I > didn't have to try many cups of McDonalds coffee to know that > it was fruitless to expect it to be any better in another > establishment with the same sign out front. > > >>On the load dump test: >> >>Here is a quick review of the results >> >>1. Eric and I gave up and I declined to publish in the detail you seem to >>need. Simply not worth the time that would be needed to reply to your >>disbelief or need to duplicate tests that may require the exact parts (as >>part type is not enough) and this thread is proof of that. >> >>2. The testing showed that there was NO problem with normal load dump as >>long as there was a battery connected to the system and NO OVP of your >>design connected (see below). > > This was predictable, easily explained and understood . . . > > >>3. We also investigated the case of NO battery as many want to have that >>as >>a backup mode of flight. As I have personally seen 3 aircraft batteries >>fail >>open in flight (two concord RG type and one Gill), I felt it was worth >>including this in the testing. > > Agreed . . . > >>Your OVP module failed 100% of the time (in >>even small load dumps) but that was expected as it clearly was not >>designed >>to support that mode of operation (no battery). > > > You got that right. This was the first time in history of aviation > as far as I've studied it that no-battery operation was brought > forth as a design goal with alternators. Generators are very > friendly in the no-battery mode. We do it all the time in today's > fleet of bizjets. Had you asked me about performance of my > product before you mis-applied it, I would have predicted the > results you demonstrated. Had you asked for a modified product > to function under a new deign goal, I would have been pleased to > try. > >>Adding a 25,000 MFD >>capacitor reduced the alternator ripple voltage but did not control the >>small load sumps and your OVP continued to trip 100% of the time, again >>not >>unexpected as the trip time was far too short to allow even a cap filtered >>load dump to pass. > > Yup, water runs down hill and the sun comes up in the east . . . > > >> Here transorbs worked well to clamp the peak load dump >>voltage spike. Adjusting the OPV trip voltage higher to allow for transorb >>clamping resolves the tripping issue with the OVP > > Or . . . one could increase the trip time-constant such that the > integrated waveform of the dump event does not add up to a value > greater than trip point . . . it's a new paradigm that needed to > be explored, values deduced, and goals established. > > >>3. The OVP module you offer as plans was built up on a 1" x 1.5" pcb and >>two >>made. Both had false trips 100% of the time when a large load was switched >>ON. This led to a simple design review of this OVP and we discovered there >>were two design errors that made the OVP sensitive to simple changes in >>bus >>voltage etc. One has been recently posted and the other is a sensitivity >>to >>contact bounce and the fast trip time. Besides the OVP design issues the >>contactor applying the load has contact bounce that was triggering the >>OVP. > > Gee Paul, I thought you were going to participate in a new > discussion about energies and dynamics of the load-dump event > as presented by alternators you had the facilities to test. > All you've done is moved off on another whack at the crowbar > OVP system which was originally designed to meet different goals and > modified as field experience suggested. You never once asked me > to participate in the gathering and analysis of data nor in the > deduction of solutions to meet your desires . . .which is the > core of my life's work as an engineer. Instead you simply > threw "rocks". You got really stirred up when instead of cowering > and capitulating under your barrage, I fielded the suckers and > of the community know them as such. > > >>There was no further effort on your OVP design (by us) as the design >>concept >>was very old and there are simple IC parts available that made a simple >>modern design with adjustable trip times off the shelf. Why try to fix >>something that is decades behind the current technology?? as the new >>design >>had built-in production against false triggering it was a win win >>solution. >>Further there is the simple opening of the contactor coil and Zero crowbar >>current as the design does not use a crowbar. > > This was never an argument. Use any OVP design philosophy that floats > your boat. The fact that you're asking something I did to meet your > new, unspecified and unanswered design goals after I've designed > and delivered the product to other goals is truly astounding. If > you use a wrench to drive nails and then complain to the wrench > supplier > about the problems you're having, the speciousness of your comments > become obvious. > > >>The solution we proposed was to be sure the OVP trip time was much longer >>than relay/contactor contact bounce (actually longer than a expected load >>dump event). Contact bounce on load removal also caused problems. I did >>post >>a reference from a major relay manufacturer that contact bounce on contact >>opening WITH a diode across the coil was very bad idea and not only was >>there contact bounce on opening there was the possibility of contact >>welding >>on opening. > > This is BS and I'm working on the paper and test report to show why. > But we can save that 'discussion' for another time. > >> Use of transorbs clipped the load dump transient and everything >>worked right thru the transient even with no battery on line. > > EXCELLENT! Now, how long was the load dump event? What was its > amplitude? > How many Joules of energy were dumped into the transorbs. What RPM were > you running the alternator. Would the transorbs you selected be > reasonably > expected to handle a moderately loaded alternator running at over > 10,000 > rpm? > > >>4. There was widespread (reported by Vans, and several builders who >>directly >>contacted me off list) false tripping by the OVP and resulting alternator >>failure where the alternator was internally regulated and the "B" lead >>contactor was the common type that not only bounced on opening (due >>largely >>to the recommended diode) and also to the resulting load dump peak voltage >>that greatly exceeded the contactor maximum contact voltage rating. Heavy >>contact arcing was documented. This resulted in the recommended Kilovac >>contactor as its the only reasonable cost contactor with the proper >>ratings >>and there is no coil diode to cause problems on contact opening. > > You've stirred a whole lot of ingredients into this paragraph. First, > vulnerability of the alternator to damage was a direct function of > adding > a means of positive control. It had to do with adding a b-lead > contactor. > It didn't matter what contactor was used, whether or not a diode was > present across the contactor or whether OVP was present. The act of > turning the alternator OFF for any reason while loaded was the proximate > cause of damage to the alternator due to inability to withstand its > own load-dump event. > > Yes, the contactor's switching limits needed review . . . yes, there > were (you say but don't document) nuisance trip issues. I've seen > hundreds of closure traces that demonstrate bounce in contacts of > relays, breakers and switches as contacts come together. I've not > seen contacts that are moving apart suddenly decided they're going > the wrong direction and come back together for some period of time. > Can you explain? Do you have any traces? What parts did this? > What was the source of forcing moments that caused parts that > were separating to reverse direction? > > >>5. We then had a system design solution with a no false tripping OVP and a >>"B" lead contactor that did not damage the alternator. Eric is now selling >>the OVP design and has on occasion the Kilovac contactors that allow safe >>"B" lead opening. > > Super! Are you telling me that this is your recommendation for > absolute control of alternators? Gee, except for establishment > and satisfaction of new design goals, this looks like Figure > Z-24 that I published years ago . . . care to share any of the > numbers that will help the rest of the world gain confidence > in your recommendations? > > >>6. I further investigated "rebuilt alternators" and found the term >>misleading. Only parts that were failed were replaced. The term should be >>repaired not rebuilt. The popular ND 55 amp alternator has been around for >>more than 20 years and many have been rebuilt several times. Who knows the >>quality of the current regulator? Thus only brand NEW alternators should >>be >>used. > > A no brainer . . . if one accepts the limitations of selecting > one's alternator from a small fraction of the total number of sources > for alternators that MIGHT be perfectly okay under YOUR design > goals. You've accused most engineers of being lazy, why did you > stop short of crafting techniques that would allow the OBAM aircraft > builder to apply ANY modern alternator "rebuilt" or not with the > only risk being short service life? That's my design goal and yes, > it will take some more work. The problem is time and equipment - > not laziness. > > >>7. Replacing the fast trip and occasional false tripping OVP with a modern >>design > > (that discards Mil-STD-704 philosophies in place for decades and > marches of to the beat of Paul's new drum . . .) > >>. . . eliminates false trips. Eliminating the Crow bar eliminated the hi >>current and its side affects (see below). If used, the proper "B" lead >>contactor will prevent alternator damage often caused by the improperly >>used >>common contactor that is not designed or specified for this specific >>application and further hindered with the incorrect application of a diode >>across the coil against major manufacturers worked wide. In fact the >>common >>diode across the coil is not recommended anywhere any time by relay >>manufacturers. > > Yup, I've read the papers cited here on the list . . . and it didn't > take 5 minutes at the bench to discount their value as drivers for > our design goals. The amazing thing was that they were published > by big names in the industry by folks with long lists of credentials. > > They took lots of good data, published some neat 'scope traces and > then drew conclusions that could have been but were not directly > measured . . . Others have read the papers and assumed that the > stature and authority of the authors was sufficient to broadly apply > their suppositions with almost religious fervor. Which underscores an > observation I made years ago . . . just because one might have run a > successful restaurant doesn't make them a good chef. > >> . . . That its very common in use does not mean its a good >>approach, It simply means that most engineers are lazy and copy what has >>been done in the past rather that research what is recommended so the >>diode >>persists even with its being the last and worst choice in a list of >>options. > > You betcha. Did YOU bother to repeat their experiments and deduce > for yourself the effects of diode-across-the-coil as we used it? > This begs the question as to who is lazy here and who worships at > the altars of Tyco-Amp, P&B, etc. > > >>IN conclusion the test results showed that much of the alternator failures >>were the direct result of the OVP design and associated contactor. Its not >>known if poor alternator regulators were a factor but even good ones are >>very likely to be damaged by the current design contactor used. Its clear >>that the contactor used has a very high potential of regulator damage and >>when coupled with a false trip prone (in some as yet defined aircraft >>wiring >>or operations) is the root cause. > > Your train of thought for cause/effect is truly amazing . . . I'm going > to save these threads for future reference. They'll be great teaching > tools. > > >>Use a modern non-crowbar OVP design and a contactor designed for the >>application resolved most of the problem. Its not possible to ignore the >>likely hood of lesser quality regulators in rebuilt alternators so only >>new >>alternators should be used. >> >>With the demonstrated extremely high reliability of the ND brand of >>internally regulated alternators is very questionable that there is a need >>for more that having the OVP simply remove the voltage to "I" lead (the >>field control lead) that shuts down the alternator. I have been unable to >>find any repair shop that has ever heard of an ND alternator having >>uncontrolled runaway failure. No output or hi output that is still >>controllable with the "I" lead. Prop bolts or crank shafts are more likely >>to fail and yes I have a report of a light twin having both engines prop >>bolts failing. > > Okay, if I republish Z-24 then all I need to do is upgrade the > contactor, recommend Eric's latest and greatest OVP product, and > add a transorb (also Eric's product?). And finally, limit > recommendations > to brand new ND alternators? If Eric's OVP is in place is a builder > on shaky ground by NOT using a new alternator . . . or even an ND > product? Can you articulate the new design goals in the form of a white > paper (the new Bible) that leads other designers down the path to > Nirvana > along with guidance as to the nature and magnitude of conditions to > expect? > (No, don't answer that. Let's go ahead and accept this as your "last > word") > >>Now for the hi current related problems. >> >>In an steel tube reinforced cockpit like the Glastar (or other production >>aircraft) its been proven that even the normal bus loads can magnetize the >>tube structure and cause compass errors of as high as 30 degrees. I >>previously referenced a manufacturers mandatory service bulletin that >>addressed this issue and also discussed with a owner of that type aircraft >>that had it happen to him. He is highly educated and a long time IA. The >>compass in question was a suspended well above the affected tubes >> >>This tells me that even 50 amp buss circuits need special wire routing and >>forget the 100+++ current transients from a crow bar. >> >>This alone says if you have a steel tubular cabin be careful and forget a >>crow bar approach. > > This was the great and evil "side effect"? Gee Paul, wouldn't > it be a good thing to simply NOT run high currents through the > structure? Cranking the engine runs far more current (with higher > inrushes) than a crowbar event will ever generate. The starter > event happens every flight-cycle. The crowbar event is much smaller > and may never happen. > > It's apparent to me that your primary driver in this exchange > has been a vendetta against one who would have the audacity to > question your autocracy in the non-dissemination of information > combined with loads of un-substantiated advice. I don't believe > this discussion had anything to do with science, the art of > building reliable systems or the enthusiastic exchange of > simple-ideas for which good teachers are noted. > > >>In any event this is my last word on either subject even if the misquoting >>etc continues. > > I have not snipped anything from your post so I cannot be accused > of any mis-quotation. It's obvious that you have no appreciation > for what it means to be a teacher or a responsible member of > an engineering community. Since you failed to substantiate any of > your allegations with data and cannot or will not answer any simple > direct question, I must conclude that this being your "last word" > on the matter is no loss to the OBAM aviation community. I look > forward to spending time on more fruitful and honorable endeavors. > > As soon as I have time and access to the equipment, I'll repeat the > tests you claim to have conducted and publish the results here and > on my website. Please ignore them . . . there are plenty of sharp > heads on the list who will help me refine my studies from which > well considered design goals can be crafted and satisfied. > > I wish you well in your new job. > > Bob . . . > > > ________________________________________________________________________________
From: KITFOXZ(at)aol.com
Date: Sep 18, 2005
Subject: Re: FW: Splice 6AWG Wire
That's a great idea about using monel or stainless to hold things together for soldering, Bob! Another idea I had forgotten about but have used at one time or another over the years is to strip the wire ends and just shove them into a short piece of common soft copper pipe and then sweat solder. Shield with heat shrink or wrap with your choice of insulator material. You could ping the pipe first or crimp it but, I think the strength of the copper pipe would be compromised. If the I.D. of the pipe and the O.D. of the wire are a perfect fit for each other, the plain old sweated solder joint is superb in my book! We are talking about a joint that is in the middle of a large diameter wire and not at a terminal connection point that may have to withstand mechanical loads. I don't like to use crimp connectors of any kind on large wires unless you are sure to use the correct crimping tool and terminal. Call me a priss but, I am concerned about the mechanical strength of large crimped joints alone and prefer to solder them along with the crimped joint. I have seen many crimped terminals work loose on large wires due to the relative motion they may have to endure. John P. Marzluf Columbus, Ohio Kitfox Outback (out back in the garage) ________________________________________________________________________________
From: "Frank Stringham" <fstringham(at)hotmail.com>
Subject: Re: RE load dump from a novice point of view
Date: Sep 18, 2005
Paul and Bob And I thought the RV7a groups primer / slider vs tip up / tail dragger vs nose roller wars were rough. Facts vs opinions ......... Facts can be demonstrated with accuracy and replicated by others with precision and similar accuracy on each trial. And as we all know opinions are like noses and other boby parts , every body's got them........plus they can usually never be replicated to any degree of accuracy and precision Even by the most knowledgeable, practiced, and skilled scientist / builder My "opinion" is that the size ($$$$$$) of the company nor the degrees of it's scientist opinions trump the facts of the little guys tried and true facts tested by both time in use and bench mark reality. Man, this electronic stuff is just coming in to view for me as I approach the wiring of my 7A. It is a whole new world to which this old retired chemistry teacher is trying to learn the language, accepted procedures, and tools needed to do the work. Bob thanks for the book of knowledge you have written, updated, and so generously give no cost updates and email instructions to those of us that are electronically challenged. Paul thanks for your knowlegeable input that questions, prods, and tests the notions of what is generally accepted by we electronically challenged plane builder. With that said I am back to my "Z" diagrams preparing for the wiring of the RV7A I am building. Frank @ sgu and slc fuse under construction / looking forward to the challenge of WIRING. >From: "Paul McAllister" <paul.mcallister(at)qia.net> >Reply-To: aeroelectric-list(at)matronics.com >To: >Subject: Re: AeroElectric-List: RE load dump >Date: Sun, 18 Sep 2005 13:42:33 -0500 > > > >Paul, > >At the risk of being accused of "snipping" your email, or offering snide >remarks, this is truly a case of an expression we use in engineering shop >where I work (a $15 billion /year company) > >It goes like, "In god we trust, everyone else bring data". Please share >it, >many of us may learn something new. > >With that said, this has been a truly enlightening discussion and the >debate >has taught me a lot (not only about engineering) > >Regards, Paul > > > > > > > I consider the entire subject (crow bar currents) closed. I feel no need > > to > > continue based on your statements as its simply not worth my time to > > reply. > > Until my comments are accepted as fact and we can get past that and deal > > with the real issues the ridicule of my test results clearly says it was >a > > mistake to ever start this in the beginning. Further the snide remarks > > from > > others does not help clear the air. > > > > ________________________________________________________________________________
From: "LarryRobertHelming" <lhelming(at)sigecom.net>
Subject: Paul M
Date: Sep 18, 2005
0.15 HTML_TEXT_AFTER_BODY BODY: HTML contains text after BODY close tag > >I consider the entire subject (crow bar currents) closed. I feel no need to >continue based on your statements as its simply not worth my time to reply. >Until my comments are accepted as fact and we can get past that and deal >with the real issues the ridicule of my test results clearly says it was a >mistake to ever start this in the beginning. Further the snide remarks from >others does not help clear the air. Paul with all due respect you deserve, you need some stretched thinking imho. I think not ridicule, I think we want details to support that gives proof to your comments. Simple...but you reject that!! Please take some time off and talk with someone about your position, the other position, AND your reluctance to give just one inch to anyone. You sound like a little kid pouting to get his way..... You have proved nothing but your arrogance and distain for Bob's expertise and respect for everyone's time who reads this list. You thumb us all by your actions. Your reluctance and defiance says something -- but I just know I think it is strange that you are not willing to be cooperative in the least bit with anyone it seems. And you consider remarks like mine snide. Please talk with someone before this gets worse. Best wishes Paul. Indiana Larry ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ " Happiness: like a butterfly, when pursued, is always beyond our grasp, but which, if one sits quietly, may light upon you." Nathaniel Hawthorne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ________________________________________________________________________________
Date: Sep 18, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: FW: Splice 6AWG Wire
> >That's a great idea about using monel or stainless to hold things together >for soldering, Bob! > >Another idea I had forgotten about but have used at one time or another over >the years is to strip the wire ends and just shove them into a short piece >of common soft copper pipe and then sweat solder. Shield with heat >shrink or >wrap with your choice of insulator material. > >You could ping the pipe first or crimp it but, I think the strength of the >copper pipe would be compromised. If the I.D. of the pipe and the O.D. >of the >wire are a perfect fit for each other, the plain old sweated solder joint is >superb in my book! > >We are talking about a joint that is in the middle of a large diameter wire >and not at a terminal connection point that may have to withstand mechanical >loads. I don't like to use crimp connectors of any kind on large wires >unless you are sure to use the correct crimping tool and terminal. > >Call me a priss but, I am concerned about the mechanical strength of large >crimped joints alone and prefer to solder them along with the >crimped joint. >I have seen many crimped terminals work loose on large wires due to the >relative motion they may have to endure. There's a certain attractiveness to the tube-over-joint method. Sure comes out slick looking on the outside when you're done. But consider that the design goal is to maximize the surface area of strands that are in close proximity to strands of the other wire and minimize the volume of solder needed to fill the inter-strand voids. Next, we'd like to maximize the solder's ability to provide mechanical support. Both goals are advanced when you interleave the strands, bind them tightly and THEN use solder to secure the joint. The example you cited about copper pipe is excellent. If one examines the gap between inner and outer walls of copper components to be joined, it is exceedingly small. So small that one must be careful not to bend the pipes out-of-round and cut ends must be carefully deburred or you cannot assemble the dry joint. Then, when the properly heated and fluxed joint flows, there's a large interfacing surface area in spite of the fact that very little solder is needed to fill the void. Crimped joints are just as strong as soldered joints when properly executed. When you have the proper materials and tools, execution is a no-brainer. But lacking those resources, solder is an excellent joining technique that is in no way inferior to a crimped joint when you UNDERSTAND and achieve the best that solder is capable of doing for you. Bob . . . ________________________________________________________________________________
Date: Sep 18, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: RE load dump
> >Hi Bob >Wow! I just joined............ I want to ask you if you think it OK for me >to proceed with my effort at hooking up my Vans 60 A int regulated alt as >follows. (I am no engineer, have little electrical knowledge)I have a B& C >cont rated contactor on the B lead which is switched by the second throw of >my Batt/Alt sw (2-10). I have, as yet no crowbar. I intend to always start >with alt switched off and stopping eng with alt switched on. I dont know how >I got here as I have the lost the thread of the latest advice and am feeling >confused. The loom all laid up, panel cut. I was ready to go and then got >hopelessly lost trying to follow this. Whilst it may not be the best >solution Bob, will this work? Absolutely! I would not discourage anyone from proceeding with any plans in place to get their projects finished and flying. Risks are small irrespective of any hazard one might wish to address in their design. Further, once rational solutions to the questions before us are derived, they're easy to add later. Don't let the floobydust flying around slow you down or worry you in the least. It's the job of folks who understand the issues and share a common interest in offering high value solutions that will happily filter the floobydust for nuggets of good data and make the results available to all along with details as to how the decisions were made. >Thanks in anticipation,Steve You're most welcome. Bob . . . ________________________________________________________________________________
Date: Sep 18, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: RE load dump from a novice point of view
> > >Man, this electronic stuff is just coming in to view for me as I approach >the wiring of my 7A. It is a whole new world to which this old retired >chemistry teacher is trying to learn the language, accepted procedures, and >tools needed to do the work. Bob thanks for the book of knowledge you have >written, updated, and so generously give no cost updates and email >instructions to those of us that are electronically challenged. You're most welcome. As a scientist, you'll appreciate my pedantic quest for underlying simple-ideas that support our design decisions. Electronics is no more difficult than chemistry. Just a different vernacular and a different box of Tinker-Toys . . . but the fundamental principals are the same and easy to grasp if you have dedicated teachers to help. On the AeroElectric-List, you're in good hands and we'll do earn your trust and respect as fellow scientists. Bob . . . ________________________________________________________________________________
Date: Sep 18, 2005
From: Tom Velvick <tomvelvick(at)cox.net>
Subject: RE: Breaker Interrupt Rating
Hi Bob, I think this is the post from 04/02/2005 that Paul is referring to. Regards, Tom Velvick >>Bob ran a test of the OVP using a CB with a resistance of 0.36 ohms. He used #20 wire, he used a 2 year old battery no longer suitable for flight. He ended up with 135 amps current thru the CB and 15 milliseconds to open. I ran a test of a my built-up version of the same OVP module. My CB a 7277 (Bob used a very similar 7274) was measures not at 0.36 ohms (the max specification resistance but 0.010 ohms. I used #4 (3 ft total and #6 wire 4 ft total and all bolted brass or copper connections) (vs. Bob's #20 wire). My battery was dual PC-625 rated at 3.5 milliohms (Bob used a Panasonic rated new at 13 milliohms and it was not new) My battery setup has a 3600 amp short circuit rating. My open time was 50-70 milliseconds. Higher current and longer times?? Seems not to make sense but that comes later. That I got 400 amps and Bob got 135 amps is reasonable and both of our tests are reasonable system tests. My test was a near exact example of my real acft.<< ________________________________________________________________________________
From: N1deltawhiskey(at)aol.com
Date: Sep 18, 2005
Subject: Re: LVW problem
Bob, Lost your response to the message below, but thanks for the offer to replace the unit if damaged. Too bad more providers of equipment are not so willing to stand by what they dump on unsuspecting people. Anyway, I reinstalled the unit and it is working fine as far as I can tell. Regards, Doug Windhorn ---------- Bob, Thanks. All of my wiring gear is at the hanger, so won't be doing this until next weekend. But in reading your response, I may have identified a/the problem. On the drawing I have, I interpreted the ground pin (-) as 5 rather than 6, and that is how I wired it. After looking more closely at the drawing, the 5's are different from the 6's - field of view (mentally) just wasn't broad enough. Think any damage was done with pin 5 grounded? I guess I will find out when I rewire and test it. Regards, Doug In a message dated 11-Sep-05 23:55:18 Pacific Standard Time, nuckollsr(at)cox.net writes: >Bob, > >I have your AEC9005-101 LVW. I am not using the battery management feature, >so have just connected the fused positive and ground wires along with the LED >wires to the unit. > >I have not seen this unit work as expected. I verified continuity of the >positive and ground wiring connections (overlooked checking the LED >connections >to be sure they were right today), but found no apparent issues with the >wiring. > >I thought I would try something else, connection the positive and ground >directly to a battery. It still did not work, but shortly thereafter I >smelled hot >insulation. I touched the wires leading to the LVM and didn't bother to hang >on - just disconnected the battery real quick. > >Any idea of what the problem might be? How can I get this working properly? >Could incorrectly wired LED wires cause this problem? (I will check those >next >time at the hanger.) Is it a defective unit? I've never had one returned. They're easy to check. Get a 9-pin d-sub female connector from Radio Shack or other handy source. Short pins 2 and 3 together. Put leadwires on pins 4 (+in) and 6 (ground). Plug your LVW/ABMM module into this connector and then connect the pin 4 wire to (+) on your car battery and pin 6 wire to (-) or ground. Engine should not be running for this test. If the module is okay, it the LED on the module will be flashing. Start the engine and repeat the test. The LED should not be flashing. Bob . . . ________________________________________________________________________________
From: "Steve Hunt" <stephen.hunt19(at)btinternet.com>
Subject: Re: RE load dump
Date: Sep 19, 2005
Bob, thanks for the reply. I along with a great many others, worldwide, are indebted to your most generous approach which is typified in your last paragraph. We really appreciate it Bob,Steve. RV8 in the UK ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> Subject: Re: AeroElectric-List: RE load dump > > > >> > >>Hi Bob > > >>Wow! I just joined............ I want to ask you if you think it OK for >>me >>to proceed with my effort at hooking up my Vans 60 A int regulated alt as >>follows. (I am no engineer, have little electrical knowledge)I have a B& C >>cont rated contactor on the B lead which is switched by the second throw >>of >>my Batt/Alt sw (2-10). I have, as yet no crowbar. I intend to always start >>with alt switched off and stopping eng with alt switched on. I dont know >>how >>I got here as I have the lost the thread of the latest advice and am >>feeling >>confused. The loom all laid up, panel cut. I was ready to go and then got >>hopelessly lost trying to follow this. Whilst it may not be the best >>solution Bob, will this work? > > Absolutely! I would not discourage anyone from proceeding with > any plans in place to get their projects finished and flying. > Risks are small irrespective of any hazard one might wish to > address in their design. Further, once rational solutions to > the questions before us are derived, they're easy to add later. > Don't let the floobydust flying around slow you down or worry > you in the least. > > It's the job of folks who understand the issues and share > a common interest in offering high value solutions that > will happily filter the floobydust for nuggets of good data > and make the results available to all along with details > as to how the decisions were made. > > >>Thanks in anticipation,Steve > > > You're most welcome. > > Bob . . . > > > ________________________________________________________________________________
Date: Sep 19, 2005
From: Ernest Christley <echristley(at)nc.rr.com>
Subject: Wire selection
I'd like to keep my wire rack nice and simple. Instead of having multiple spools of various wire sizes, I think it would be beneficial to have just one spool of a multistranded cable. I don't see it weighing significantly more. There's just not enough wire in the plane to make a difference. The cable is more expensive, but the installation would be simpler and safer. Simpler since, for instance, there would only be one run of wire out to the wingtip lights. Safer since the wire by default would have an extra jacket. Before anyone gets a chance to say it, I am indeed accepting a less than optimum design in exchange for a lack of the need to plan carefully. My response is that the offset from optimum will not have measurable results in the final product, and the best laid plans of mice and men... (so, it's 4:00 on Saturday. You've got a roll of 22AWG left, but what you really need is 2ft of 20AWG. Aaargh!) So, with this goal in mind, what would be a good wire size that would basically cover all the wiring needs, with the obvious exception of the starter? 18AWG? 20AWG? Certain high current devices, like pitot heat, could use multiple strands in a cable, or lower current technologies, like Eric's thermal switch design. Stenair has 3 and 4 strand cables of 22AWG, which I think is a little small. Is there a good source for larger aviation grade cables? -- ,|"|"|, | ----===<{{(oQo)}}>===---- Dyke Delta | o| d |o www.ernest.isa-geek.org | ________________________________________________________________________________
Date: Sep 19, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: LVW problem
> >Bob, > >Lost your response to the message below, but thanks for the offer to replace >the unit if damaged. Too bad more providers of equipment are not so willing >to stand by what they dump on unsuspecting people. > >Anyway, I reinstalled the unit and it is working fine as far as I can tell. > >Regards, > >Doug Windhorn Great! While reflecting on past conversations with Paul and pondering the missing pieces of his puzzles, I tried to recall every troubleshooting task I've taken on over the years. The most recent experiences were the easiest and no doubt some are lost to the ages but I could not remember a single instance where root cause of a problem turned out to be a "violation" of manufacturer's specifications for a part. In every case, the problem was some very simple mechanical error of installation, an error in programming, or failure of a supplied component to meet his own specifications. My most recent task was to find a bad pin in a very hard to reach set of connectors that would only open at altitude. We had to install a data acquisition system, put an x-ticket on the airplane and fly it to 38K to get our arms around the failure. Finding the bad pin cost my company a bucket full of money, and months of frustration on the part of the owner of a new airplane who seemed to believe that for $6 million the thing really should work right. I was fairly certain that your problem fell into the "really simple" category . . . all we had to do was find it. As it turns out, I need to fix my published data so as to not set the installer up for the error you suffered. While your experience was frustrating and time consuming for you, sharing it here on the List prompted actions that will benefit those who follow you. To me, this is the finest example of how the consumer/supplier relationships ought to run. Thanks! I mention this for the benefit of folks who may have been feeling lost and frustrated trying to follow the thread on design and architecture issues. While it may have seemed like a really big deal, it was in fact much ado about very little because some of the participants couldn't focus on science and the excitement of problem solving. I just received a phone call from a very good friend of mine who is my mechanical counterpart here in Wichita. He thinks in gears, motors and leadscrews like I think in switches and microchips. We're going to have lunch today. We'll no doubt wrestle with some of the world's design problems on the back of some napkins . . . just for fun. One such lunch seeded a solution for the flap system that flies on Eclipse today. 100% failure free since first article was delivered about two years ago. I would have been delighted if Paul (or Eric) could have participated in the same spirit and excitement and exploration of the possibilities as I enjoy with too few folks in Wichita. Contributions to the OBAM aircraft community could have been significant. We'll still get there . . . just a little slower perhaps. In the mean time, we have over a century of aviation history and success stories upon which we can rely for any project that is already under way and should continue to move ahead with confidence. Real improvements come in tiny pieces that can be added any time. Most OBAM aircraft will evolve just like spam cans have for a century. Bolt-on accessories to the panel or engine. However, a few will be proving test beds for incremental changes to architectures and new I hope that owners of such aircraft will be participants here on the List and will share their experiences and achievements with all of us. I'll do what I can to make their efforts exciting and rewarding. Bob . . . ________________________________________________________________________________
From: "Stein Bruch" <stein(at)steinair.com>
Subject: Wire selection
Date: Sep 19, 2005
While in theory this might be sound, for a variety of reasons I'd urge you to re-consider your approach. You'd be surprised at how much weight wire can add. If you go with AWG18 (which you'll need some of) for the whole match and used shielded cable, you'll add quite a few pounds to your plane. You're right, AWG 22 just won't cut it for the whole plane, and just picking multiple strands for power isn't always the best way to go either. To do your plane, you'll probably need: AWG8 or something like that for Alternator feed line AWG14 or 16 for pitot heat AWG16 for decent sized landing lights AWG18 for things like flaps motors, strobe power, nav lights, master relay, boost pumps, etc... AWG18 or 20 Shielded for Magneto "P" leads. AWG20 for powering things like Autopilot servos, avionics, etc.. AWG22 for powering other things and for sensor wires. Shielded wire SEPARATE From everything else for audio wires, headset jacks, etc.. It's pretty hard to get away from at least a basic variety of wire in a normal aircraft wiring scheme. I'm not flaming your approach, just trying to point out that it would be difficult at best for a variety of reasons to use one type of multi-stranded cable. Just my 2 cents as usual. Cheers, Stein. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Ernest Christley Subject: AeroElectric-List: Wire selection I'd like to keep my wire rack nice and simple. Instead of having multiple spools of various wire sizes, I think it would be beneficial to have just one spool of a multistranded cable. I don't see it weighing significantly more. There's just not enough wire in the plane to make a difference. The cable is more expensive, but the installation would be simpler and safer. Simpler since, for instance, there would only be one run of wire out to the wingtip lights. Safer since the wire by default would have an extra jacket. Before anyone gets a chance to say it, I am indeed accepting a less than optimum design in exchange for a lack of the need to plan carefully. My response is that the offset from optimum will not have measurable results in the final product, and the best laid plans of mice and men... (so, it's 4:00 on Saturday. You've got a roll of 22AWG left, but what you really need is 2ft of 20AWG. Aaargh!) So, with this goal in mind, what would be a good wire size that would basically cover all the wiring needs, with the obvious exception of the starter? 18AWG? 20AWG? Certain high current devices, like pitot heat, could use multiple strands in a cable, or lower current technologies, like Eric's thermal switch design. Stenair has 3 and 4 strand cables of 22AWG, which I think is a little small. Is there a good source for larger aviation grade cables? -- ,|"|"|, | ----===<{{(oQo)}}>===---- Dyke Delta | o| d |o www.ernest.isa-geek.org | ________________________________________________________________________________
Date: Sep 19, 2005
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: RE: Breaker Interrupt Rating
> >Hi Bob, > >I think this is the post from 04/02/2005 that Paul is referring to. >Regards, >Tom Velvick Thank you for tracking this down! I've found the whole message and printed it off. I don't know how I missed it but it there was a lot going on . . . sometimes with replies passing each other in cyberstream. I'll ponder it for a bit. Appreciate your help. Bob . . . ________________________________________________________________________________
Date: Sep 19, 2005
From: rv-9a-online <rv-9a-online(at)telus.net>
Subject: Re: Wire selection
Stein covered the weight issue, but there is another consideration... the diameter of the wiring bundles is important when routing through spars, wings, snap bushings and so on. Using shielded wire everywhere would significantly increase your routing problems. Vern Little RV-9A ready to move the airport! Ernest Christley wrote: > >So, with this goal in mind, what would be a good wire size that would >basically cover all the wiring needs, with the obvious exception of the >starter? 18AWG? 20AWG? Certain high current devices, like pitot heat, >could use multiple strands in a cable, or lower current technologies, >like Eric's thermal switch design. Stenair has 3 and 4 strand cables of >22AWG, which I think is a little small. Is there a good source for >larger aviation grade cables? > > > ________________________________________________________________________________
Subject: Re: Wire selection
Date: Sep 19, 2005
From: "John Schroeder" <jschroeder(at)perigee.net>
Ernest - I wholeheartedly agree with Stein. It is not that difficult to do some measurements and then increase the lengths by a foot or two to get a requirement for the wire. Wire is relatively cheap. Shielded cable is much more expensive. I'd order 25% more of each wire size than you calculate you will need - to get past that ooops factor. John > > > While in theory this might be sound, for a variety of reasons I'd urge > you > to re-consider your approach. You'd be surprised at how much weight wire > can add. If you go with AWG18 (which you'll need some of) for the whole > match and used shielded cable, you'll add quite a few pounds to your > plane. > You're right, AWG 22 just won't cut it for the whole plane, and just > picking > multiple strands for power isn't always the best way to go either. > -- ________________________________________________________________________________
Date: Sep 19, 2005
From: Dj Merrill <deej(at)thayer.dartmouth.edu>
Subject: Re: RE load dump
Steve Hunt wrote: > I have, as yet no crowbar. I intend to always start > with alt switched off and stopping eng with alt switched on. I dont know how > I got here as I have the lost the thread of the latest advice and am feeling > confused. Hi Steve, I have Bob's crowbar OV design in my Glasair with an O320 in it, and I also have one of Eric's LVW modules installed (http://www.periheliondesign.com/lvwaabm.htm). I've been using the method you mention for the last year or so with no apparent ill effects. Ie: 1) Alternator switch off, turn on Master switch 2) Check for red blinky light indicating low voltage (should be on) 3) Start engine 4) Turn on alternator switch, check for red blinky light to go out indicating alternator is working and producing voltage Turn off engine, turn off master, and then turn off alt switch. However, based on discussions on this list recently, I'm considering slightly altering my startup process to: 1) Alternator switch off, turn on Master switch 2) Check for red blinky light indicating low voltage (should be on) 3) Turn on alternator switch (light should still be on) 4) Start engine 5) Check for red blinky light to go out indicating alternator is working and producing voltage Shutdown would remain the same - engine off, master off, alt off. The reason for the change is that there is a possibility that the alternator does not liked be "turned on" when it is already spinning, and there may be a chance of doing harm. While this may not in reality be true (I'm not sure), I don't see any harm in having the alternator switch turned on while starting the engine. Please note these are just my opinions - I'm not an expert. However, it seems to work for me. -Dj -- Dj Merrill Sportsman 2+2 Builder #7118 "Many things that are unexplainable happen during the construction of an airplane." --Dave Prizio, 30 Aug 2005 "TSA: Totally Screwing Aviation" ________________________________________________________________________________
From: Kevin Horton <khorton01(at)rogers.com>
Subject: Re: Wire selection
Date: Sep 19, 2005
On 19-Sep-05, at 11:15 AM, Ernest Christley wrote: > > > So, with this goal in mind, what would be a good wire size that would > basically cover all the wiring needs, with the obvious exception of > the > starter? 18AWG? 20AWG? Certain high current devices, like pitot > heat, > could use multiple strands in a cable, or lower current technologies, > like Eric's thermal switch design. Stenair has 3 and 4 strand > cables of > 22AWG, which I think is a little small. Is there a good source for > larger aviation grade cables? > If you try to use multiple strands in a cable, you have lost the protection from a fuse or CB, unless you put a fuse on each strand. If you use one fuse or CB for the device, and you use multiple strands to feed that device, a short on one strand could lead to an electrical fire, as the CB rating will be too high than needed for a strand of that size. This is a corner I wouldn't cut. Kevin Horton Ottawa, Canada RV-8 - Finishing Kit http://www.kilohotel.com/rv8 ________________________________________________________________________________
From: Phil Birkelbach <phil(at)petrasoft.net>
Subject: Re: RE load dump
Date: Sep 20, 2005
Come on Paul! Do you really think that you can use the phrase "Until my comments are accepted as fact.." and then not support those comments with any numbers that you can then say "...the ridicule of my test results clearly says it was a mistake..." No one is ridiculing your test results because no one has seen your test results. As far as I can remember you have never even shown us a diagram of your test setup. You say that you decline to publish in the detail that we want, but I don't want a lot of detail I'd probably be happy with a description of the test apparatus and a brief paragraph explaining the procedure and a graph or two. If this information exists and I've missed it please point out my error. We are all members of this list because we are building airplanes that need electrical systems in them. This list is not an academic one, although academics surely plays a major role. We would all like to build the most reliable systems that we can with the money that we have. To achieve this balance we need to be able to make decisions on what kind of risk we are willing to live with based on the mission of our airplane and where to spend our money to achieve that. To do that we need to be educated on the benefits and drawbacks of the different systems, and ideas. You and Eric seem to think that this list is a religious list where we all just do what Bob tells us to do. I must admit that the electrical system in my RV-7 is made up, almost entirely, of Bob's ideas. Most of which I completely disagreed with the first time I read them. I didn't do that because I decided that Bob was the electron god of aviation. I did that because through simple ideas, logic and PHYSICS I became convinced that it was the right solution for my mission and my pocketbook. I can't use any of the information that you seem to have to that end because I don't know where that information is. If you published a white paper on the "Load Dump Issue," and showed that some of Bob's ideas were flawed I bet you that he'd publish that white paper on his own website. If he doesn't then that hurts his own credibility. The fact that there is no such white paper leads me to believe that you yourself don't think that your data will stand up to public scrutiny. It may be way over my head, but once published in the public domain the credence of the numbers goes up because they are then under review. All we have now is "Cold Fusion." We are supposed to believe what you say because you told us you did the test. I am at a point with my airplane where I really need to know the answer to this issue. I have an operational problem with my ND IR 40A alternator that has Bob's CB OVM on it. I have the good old $15 contactor on the B lead. I also have an SD-8 backup alternator. What I didn't realize during the design of my system was that the SD-8 wouldn't put out enough voltage to allow me to check it at idle. So now I have to either stay on battery power until I get to the run up area, risk turning off the B-lead contactor when I get to the run up area or simply not check the SD-8 during pre-flight. I could run the engine up to 1500 RPM or so right in front of the hangar but that upsets the neighbors and since the oil hasn't had a chance to come up to temperature yet, it's not the best thing to do on the engine. If the "Load Dump" issue were quantified I could make an intelligent choice on whether to keep the system I have and shut the alternator down at run up, or to seriously think about changing to an externally regulated alternator. As far as I know all I have to help me with this decision is a bunch of arguing about the ethereal ghost of load dump that may or may not exist under different conditions. An oscilloscope trace and a schematic would make all the difference in the world. Phil On Sep 18, 2005, at 10:16, Paul Messinger wrote: > > > I consider the entire subject (crow bar currents) closed. I feel no > need to > continue based on your statements as its simply not worth my time > to reply. > Until my comments are accepted as fact and we can get past that and > deal > with the real issues the ridicule of my test results clearly says > it was a > mistake to ever start this in the beginning. Further the snide > remarks from > others does not help clear the air. > > On the load dump test: > > Here is a quick review of the results > > 1. Eric and I gave up and I declined to publish in the detail you > seem to > need. Simply not worth the time that would be needed to reply to your > disbelief or need to duplicate tests that may require the exact > parts (as > part type is not enough) and this thread is proof of that. > > 2. The testing showed that there was NO problem with normal load > dump as > long as there was a battery connected to the system and NO OVP of your > design connected (see below). > > 3. We also investigated the case of NO battery as many want to have > that as > a backup mode of flight. As I have personally seen 3 aircraft > batteries fail > open in flight (two concord RG type and one Gill), I felt it was worth > including this in the testing. Your OVP module failed 100% of the > time (in > even small load dumps) but that was expected as it clearly was not > designed > to support that mode of operation (no battery). Adding a 25,000 MFD > capacitor reduced the alternator ripple voltage but did not control > the > small load sumps and your OVP continued to trip 100% of the time, > again not > unexpected as the trip time was far too short to allow even a cap > filtered > load dump to pass. Here transorbs worked well to clamp the peak > load dump > voltage spike. Adjusting the OPV trip voltage higher to allow for > transorb > clamping resolves the tripping issue with the OVP > > 3. The OVP module you offer as plans was built up on a 1" x 1.5" > pcb and two > made. Both had false trips 100% of the time when a large load was > switched > ON. This led to a simple design review of this OVP and we > discovered there > were two design errors that made the OVP sensitive to simple > changes in bus > voltage etc. One has been recently posted and the other is a > sensitivity to > contact bounce and the fast trip time. Besides the OVP design > issues the > contactor applying the load has contact bounce that was triggering > the OVP. > > There was no further effort on your OVP design (by us) as the > design concept > was very old and there are simple IC parts available that made a > simple > modern design with adjustable trip times off the shelf. Why try to fix > something that is decades behind the current technology?? as the > new design > had built-in production against false triggering it was a win win > solution. > Further there is the simple opening of the contactor coil and Zero > crowbar > current as the design does not use a crowbar. > > The solution we proposed was to be sure the OVP trip time was much > longer > than relay/contactor contact bounce (actually longer than a > expected load > dump event). Contact bounce on load removal also caused problems. I > did post > a reference from a major relay manufacturer that contact bounce on > contact > opening WITH a diode across the coil was very bad idea and not only > was > there contact bounce on opening there was the possibility of > contact welding > on opening. Use of transorbs clipped the load dump transient and > everything > worked right thru the transient even with no battery on line. > > 4. There was widespread (reported by Vans, and several builders who > directly


September 09, 2005 - September 20, 2005

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