AeroElectric-Archive.digest.vol-bc

August 25, 2002 - September 09, 2002



      
      
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Date: Aug 25, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Second battery for auto engined a/c
I've just started flying my Zodiac 601HDS with a subaru stratus engine. I have partial redundancy in an automobile type ignition with 2 coils & 2 coil firing systems and single distr. & plugs. I have 2 fuel pumps (no gravity feed) I run on one or the other coils & fuel pumps. When I flew a Lyc. I remember hearing about dual batteries systems for planes like my Zodiac, but it was not very important to me with my Lyc. powered Long EZ. That was then & this is now. Bottom line: I'm looking for a wiring diagram to install a second battery for more complete redundancy; can you help me? Thank you, Figures Z-29 and Z-30 in the current issue of the book show how to add a second battery. When you do this, consider making the two batteries smaller but identical so that you don't take a big weight hit. I'd run half the engine critical stuff from main battery bus, the other half from the aux battery bus. During alternator out ops, run engine only from aux battery, e-bus from main battery. Swap new battery into main slot every year and move main battery to aux slot. If you don't have the latest issue of book, you can download updates from: http://216.55.140.222/articles.html Bob . . . |-------------------------------------------------------| | There is a great difference between knowing and | | understanding: you can know a lot about something and | | not really understand it. -C.F. Kettering- | |-------------------------------------------------------| ________________________________________________________________________________
Date: Aug 25, 2002
From: richard(at)riley.net
Subject: Re: Fwd: Re: Alternators
Works fine for me. Must be gremlins in the Internet. :) > > > >Bob: > >I'm in the process of fitting out and wiring the panel on my RV-6A, and >have been studying your manual (October 2000). Way back, I purchased a 60A >alternator (Nippon Denso) from Van's, which has a built in regulator. I'd >like to modify the alternator per your Note 11, Appendix Z, i.e. to use an >external regulator. The alternator connector has three terminals, of which >only one is used and brought back to the panel. What would I have to do to >be able to use an external regulator? > > Unless you are skilled and experienced in this modification, > I recommend you use external ov protection a-la Figure > Z-24. You might also find a local automotive ovehaul shop > that could do it for you but even then, there are some machining > steps and new hardware that needs to be installed to do it > really right. > > By the way, you can update your book with downloads available > from our website at: > > http://216.55.140.222/articles.html > > >Incidentally, I've tried to use the B&C web site for 'products' and cannot >gain access. Is it down? > > We've had some network glitches over the past few days. I > think it's up and stable now. > > > Bob . . . > > |-------------------------------------------------------| > | There is a great difference between knowing and | > | understanding: you can know a lot about something and | > | not really understand it. -C.F. Kettering- | > |-------------------------------------------------------| > > ________________________________________________________________________________
Date: Aug 25, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Navigation Select Switch
> > > >In the pure analog world, you'll to switch > > between 14 and 18 wires from the indicator to the two radios. > > This take a 18 pole, double throw switch . . . > >Could this be an application for those old computer printer switches? They >switch 25 inputs to either of 25 outputs. Don't know why this wouldn't work. Bob . . . ________________________________________________________________________________
Date: Aug 25, 2002
From: RSwanson <rswan19(at)comcast.net>
Subject: Scam
Did anyone else on this list get email form some banker in Nigeria. I did a search for the email address I use to subscribe and the aeroelectric archives was the only hit that came back. Be advised that ANYTHING that comes from Nigeria is a scam. R ________________________________________________________________________________
From: "Harley, Ageless Wings" <Harley(at)AgelessWings.com>
Subject: Scam
Date: Aug 25, 2002
>>Did anyone else on this list get email form some banker in Nigeria. ... Be advised that ANYTHING that comes from Nigeria is a scam.<< It is indeed a scam...and a serious one. There are dozens of variations of that email, and ALL of them are an attempt to get an account number from you so it can be emptied. NOT so they can put money in it! To read all about it, and see copies of many of the variations of this scam, go here: http://urbanlegends.about.com/library/blnigeria.htm?terms=nigeria Harley ________________________________________________________________________________
Date: Aug 25, 2002
From: Robert McCallum <robert.mccallum2(at)sympatico.ca>
Subject: Re: Navigation Select Switch
"Robert L. Nuckolls, III" wrote: > > > > >In the pure analog world, you'll to switch > > > between 14 and 18 wires from the indicator to the two radios. > > > This take a 18 pole, double throw switch . . . > > > >Could this be an application for those old computer printer switches? They > >switch 25 inputs to either of 25 outputs. > > Don't know why this wouldn't work. > > Bob . . . > > _ Are you sure that those switches actually connect to, and switch ALL pins of the 25 pin connector??? I believe that printer cables actually contain only approx. 10 wires or so even though they use a 25 pin connector. I could be VERY wrong, I'm far from knowing very much about computers but we use a 25 pin "computer" cable in some machinery we build at work and I know for sure a printer cable won't work. I was told this was because all of the pins aren't connected in a printer cable and the cable we use needs all 25. -- Bob McC ________________________________________________________________________________
From: CBFLESHREN(at)aol.com
Date: Aug 25, 2002
Subject: Re: Scam
Yeah , I've been getting that scam attempt for several months now. Don't know how I got on their list . They're trying to get your bank account numbers, claiming you can help them get millions of dollars (or whatever they use) out of their country because some political coup made it available to them . They'll just transfer it into your account to get it out of the country & you get to keep some of it ! It's hard to believe ANYONE would fall for this . Someone must have because they keep trying .. Chris Fleshren ________________________________________________________________________________
From: "Harley, Ageless Wings" <Harley(at)AgelessWings.com>
Subject: Scam
Date: Aug 25, 2002
>>It's hard to believe ANYONE would fall for this . Someone must have because they keep trying ..<< To the tune of 100s of MILLIONS of dollars annually! And not just that, some people have also flown over there with their money, and then found themselves held hostage, even tortured. The secret service is heavily involved in trying to stop it. Harley ________________________________________________________________________________
From: "Ed Anderson" <eanderson(at)carolina.rr.com>
Subject: Re: Scam
Date: Aug 25, 2002
----- Original Message ----- From: "RSwanson" <rswan19(at)comcast.net> Subject: AeroElectric-List: Scam > > Did anyone else on this list get email form some banker in Nigeria. I did a > search for the email address I use to subscribe and the aeroelectric > archives was the only hit that came back. Be advised that ANYTHING that > comes from Nigeria is a scam. > R > I've started getting ones with a little bit more personalization. Like a William Anderson died there and left $7.0M (could build a few RVs with that!) so this Barrister contacts me as an Anderson to give me this opportunity of a life-time {:>) to help out a "relative" and of course I get to keep a big chunk of the change. Sadly enough, apparently plenty of folks do fall for it. My old mother always said that if something appeared too good to be true, the odds were certain that it was not. I always view any contact that wants to talk to me about $$, wants to talk me out of some of MINE! Ed Anderson ________________________________________________________________________________
Date: Aug 25, 2002
From: "Paul A. Franz, P.E." <paul(at)eucleides.com>
Subject: Re: Scam
At 05:21 PM 8/25/2002CBFLESHREN(at)aol.com sez: > > Yeah , I've been getting that scam attempt for several months now. Don't >know how I got on their list . They're trying to get your bank account >numbers, claiming you can help them get millions of dollars (or whatever they >use) out of their country because some political coup made it available to >them . They'll just transfer it into your account to get it out of the >country & you get to keep some of it ! It's hard to believe ANYONE would >fall for this . Someone must have because they keep trying .. Chris >Fleshren It's been going on for more than 50 years. Started in postal mail then in the 80's migrated to FAX and starting in 1999 migrated to e-mail. They are so well known they are called Nigerian 419 Frauds. And thousands of people have fallen for their schemes and have lost loads of money. One they get a sucker on the hook they start finding complications that require payments of cash bribes. Sometimes even requiring a visit to Nigeria. When there, you find you don't have the correct visa but alas, no problemo - they find you forged papers then when you're in you are black mailed because immigration fraud is a severe crime there. You can read endless stories about the Nig. 419 fraud on the various Urban Legends sites. Google is your friend. If you get a Nig. 419 scam via e-mail send it complete with full headers to the US Secret Service. They investigate these. They have a special reporting address: for reporting Nig. 419 scams I have been getting a couple of Nig. 419 scams every week for months now. Paul Franz PAF Consulting Engineers | 427 - 140th Ave NE (425)641-8202 voice | Bellevue, WA 98005 (425)641-1773 fax | <http://blackdog.bellevue.wa.us/> ________________________________________________________________________________
Date: Aug 25, 2002
From: RSwanson <rswan19(at)comcast.net>
Subject: Re: Scam
Thanks for the address. I just forwarded one to the SS. R ----- Original Message ----- From: "Paul A. Franz, P.E." <paul(at)eucleides.com> Subject: Re: AeroElectric-List: Scam > > At 05:21 PM 8/25/2002CBFLESHREN(at)aol.com sez: > > > > Yeah , I've been getting that scam attempt for several months now. Don't > >know how I got on their list . They're trying to get your bank account > >numbers, claiming you can help them get millions of dollars (or whatever they > >use) out of their country because some political coup made it available to > >them . They'll just transfer it into your account to get it out of the > >country & you get to keep some of it ! It's hard to believe ANYONE would > >fall for this . Someone must have because they keep trying .. Chris > >Fleshren > > It's been going on for more than 50 years. Started in postal mail then in > the 80's migrated to FAX and starting in 1999 migrated to e-mail. They are > so well known they are called Nigerian 419 Frauds. > > And thousands of people have fallen for their schemes and have lost loads > of money. One they get a sucker on the hook they start finding > complications that require payments of cash bribes. Sometimes even > requiring a visit to Nigeria. When there, you find you don't have the > correct visa but alas, no problemo - they find you forged papers then when > you're in you are black mailed because immigration fraud is a severe crime > there. > > You can read endless stories about the Nig. 419 fraud on the various Urban > Legends sites. Google is your friend. > > If you get a Nig. 419 scam via e-mail send it complete with full headers to > the US Secret Service. They investigate these. They have a special > reporting address: > > for reporting Nig. 419 scams > > I have been getting a couple of Nig. 419 scams every week for months now. > > > Paul Franz > > PAF Consulting Engineers | 427 - 140th Ave NE > (425)641-8202 voice | Bellevue, WA 98005 > (425)641-1773 fax | > <http://blackdog.bellevue.wa.us/> > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
Date: Aug 25, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Navigation Select Switch
> > >"Robert L. Nuckolls, III" wrote: > > > > > > > > >In the pure analog world, you'll to switch > > > > between 14 and 18 wires from the indicator to the two radios. > > > > This take a 18 pole, double throw switch . . . > > > > > >Could this be an application for those old computer printer > switches? They > > >switch 25 inputs to either of 25 outputs. > > > > Don't know why this wouldn't work. > > > > Bob . . . > > > > _ >Are you sure that those switches actually connect to, and switch ALL pins >of the 25 pin connector??? >I believe that printer cables actually contain only approx. 10 wires or so >even though they use a 25 >pin connector. I could be VERY wrong, I'm far from knowing very much about >computers but we use a 25 >pin "computer" cable in some machinery we build at work and I know for >sure a printer cable won't >work. I was told this was because all of the pins aren't connected in a >printer cable and the cable >we use needs all 25. I've only purchased two of these things in my lifetime. Both models did indeed switch all 25 pins independently from one common input connector to two output connectors. Obviously, one COULD sell a 25-pin device which carries only those few wires needed to communicated with a parallel printer port. But it would be an easy thing to check for before you purchased one. Bob . . . ________________________________________________________________________________
From: N1deltawhiskey(at)aol.com
Date: Aug 26, 2002
Subject: Splitting encoder output
This question is for anyone. I am looking at a situation in which I will have two devices which will utilize encoder output. Am looking for an "elegant" method of doing this, other than Y-ing individual wires. Anyone know of such a solution? Thanks in advance. Doug Windhorn ________________________________________________________________________________
From: "John Warren" <jwdub(at)teleport.com>
Subject: Re: Push to Start Button Circuit
Date: Aug 26, 2002
Bob, I believe I found the problem. First, the starter contactor turned out to be for a 6v system and the hot wire from the battery contactor to the starter contactor was in bad shape. It had broken strands in the bundle where it was crimped and the insulation had obviously overheated. The damage to the wire was only on the side toward the firewall and was not visible from the cockpit side. RV-3's don't provide much access! I installed new wire and a new contactor to be sure. Haven't had time to try starting the engine yet, but I'm confident the mystery has been solved. Thanks for your thoughts. John Warren La Center Wa RV-3A RV-6 in progress ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: Push to Start Button Circuit > > > > >Bob, > > > >My appologies, I re-read my message and realized that I stated that the push > >to start switch went to the starter solenoid, when in fact it is an external > >intermitent starter contactor like your S702-1. Unfortunately my copy of > >your manual only goes to Z-18 and I'm unable to connect to your article site > >reference. Does the above change your answer? > > Hmmm . . . beats me. Our S702-1 has about a 3-ohm coil which draws > about 4A when energized. Have you measured the coil resistance > of your contactor? > > Bob . . . > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
Date: Aug 26, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Push to Start Button Circuit
> >Bob, > >I believe I found the problem. First, the starter contactor turned out to >be for a 6v system and the hot wire from the battery contactor to the >starter contactor was in bad shape. It had broken strands in the bundle >where it was crimped and the insulation had obviously overheated. The >damage to the wire was only on the side toward the firewall and was not >visible from the cockpit side. RV-3's don't provide much access! I >installed new wire and a new contactor to be sure. Haven't had time to try >starting the engine yet, but I'm confident the mystery has been solved. >Thanks for your thoughts. Oops! Where did you find a 6v contactor? Pleased you've got the dragon tamed and saddled. Bob . . . ________________________________________________________________________________
Date: Aug 26, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Push to Start Button Circuit
> >Bob, > >I believe I found the problem. First, the starter contactor turned out to >be for a 6v system and the hot wire from the battery contactor to the >starter contactor was in bad shape. It had broken strands in the bundle >where it was crimped and the insulation had obviously overheated. The >damage to the wire was only on the side toward the firewall and was not >visible from the cockpit side. RV-3's don't provide much access! I >installed new wire and a new contactor to be sure. Haven't had time to try >starting the engine yet, but I'm confident the mystery has been solved. >Thanks for your thoughts. > >John Warren >La Center Wa >RV-3A >RV-6 in progress >----- Original Message ----- >From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> >To: >Subject: Re: AeroElectric-List: Push to Start Button Circuit > > > > > > > > > > > >Bob, > > > > > >My appologies, I re-read my message and realized that I stated that the >push > > >to start switch went to the starter solenoid, when in fact it is an >external > > >intermitent starter contactor like your S702-1. Unfortunately my copy of > > >your manual only goes to Z-18 and I'm unable to connect to your article >site > > >reference. Does the above change your answer? > > > > Hmmm . . . beats me. Our S702-1 has about a 3-ohm coil which draws > > about 4A when energized. Have you measured the coil resistance > > of your contactor? > > > > Bob . . . > > > > >http://www.matronics.com/browselist/aeroelectric-list > > > > > > Bob . . . |-------------------------------------------------------| | There is a great difference between knowing and | | understanding: you can know a lot about something and | | not really understand it. -C.F. Kettering- | |-------------------------------------------------------| ________________________________________________________________________________
Date: Aug 26, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Push to Start Button Circuit - Follow Up
> >Bob, > >I believe I found the problem. First, the starter contactor turned out to >be for a 6v system and the hot wire from the battery contactor to the >starter contactor was in bad shape. It had broken strands in the bundle >where it was crimped and the insulation had obviously overheated. The >damage to the wire was only on the side toward the firewall and was not >visible from the cockpit side. RV-3's don't provide much access! I >installed new wire and a new contactor to be sure. Haven't had time to try >starting the engine yet, but I'm confident the mystery has been solved. >Thanks for your thoughts. Ignore the SECOND response to this . . . fingers moving too fast and too sloppy on the keyboard. Another thing to check on is whether or not your contactor has a built in spike catcher diode. If not, be sure to add one externally. The intermittent duty contactor can really EAT starter buttons. Bob . . . ________________________________________________________________________________
From: "Phil Birkelbach" <phil(at)petrasoft.net>
Subject: DO-160 Circuit Questions
Date: Aug 26, 2002
Bob and Others, I am working on a little trim controller circuit and I have a few questions concerning how to make this circuit robust enough to survive in my airplane. I have posted a circuit drawing at... ftp://ftp.w-industries.com/pub/phil/circuit.jpg Right now I am worried about a couple of things. One are surges and spikes. I don't know how well the 7805 will handle these on it's own. Should I move up to say an LM317 or will this work okay? I suspect I may need some kind of zenner shunt but I know very little about such things. Also deep down in the control circuit block is an IC that I would like to put in a socket so that it can be removed for reprogramming. It is a PIC16F73. I have known of a few sockets rejecting their host IC after a few years of use/abuse/temperature fluctuations. I suspect that the vibration of an airplane would cause the IC to depart the socket in fairly short order. I could use a ZIF socket but if this thing turned marketable I would hate to have to add $10 to a $20 circuit for a ZIF socket. I am sure that there are some good sockets out there but I don't know what to begin to look for. Godspeed, Phil Birkelbach - Houston Texas RV-7 N727WB (Reserved) http://www.myrv7.com Fuselage Airplanes never win battles with the ground. The best the airplane can hope for is a draw. ________________________________________________________________________________
Date: Aug 26, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: DO-160 Circuit Questions
> > >Bob and Others, > >I am working on a little trim controller circuit and I have a few >questions concerning how to make this circuit robust enough to survive >in my airplane. I have posted a circuit drawing at... >ftp://ftp.w-industries.com/pub/phil/circuit.jpg Tried to download this but the page came up "unavailable" . . . >Right now I am worried about a couple of things. One are surges and >spikes. I don't know how well the 7805 will handle these on it's own. >Should I move up to say an LM317 or will this work okay? I suspect I >may need some kind of zenner shunt but I know very little about such >things. Assuming you're designing for a 14v airplane, the short term surge requirement is 40v for, I believe, 100 uSeconds. The HV versions of the LM317 will handle this. Or, depending on your current draw, a series resistance in the supply line to the 7805 followed by a shunt zener or transorb works better yet. This will cover your 300V spike requirement too. >Also deep down in the control circuit block is an IC that I would like >to put in a socket so that it can be removed for reprogramming. It is a >PIC16F73. I have known of a few sockets rejecting their host IC after a >few years of use/abuse/temperature fluctuations. I suspect that the >vibration of an airplane would cause the IC to depart the socket in >fairly short order. Not really. Use a good brand of machined pin socket and then arrange for some simple tie down. I've used a string tie trough two holes in the board to hold chips in their sockets. Actually, I think your chips would stay in place without being tied down . . . but everyone likes a "security blanket". Vibration in airplanes really isn't as bad as some folks would like us to believe it is. > I could use a ZIF socket but if this thing turned >marketable I would hate to have to add $10 to a $20 circuit for a ZIF >socket. I am sure that there are some good sockets out there but I >don't know what to begin to look for. I presume were talking about dual in-line pin parts. For more robust interchangeability during early production, consider soldering your parts into machined pin sockets to give them more robust pins. Then plug the assembly into another socket. This isn't a bad way to go for long term production for robust, plug-able chips. Take a peek at the download problem . . . Bob . . . |-------------------------------------------------------| | There is a great difference between knowing and | | understanding: you can know a lot about something and | | not really understand it. -C.F. Kettering- | |-------------------------------------------------------| ________________________________________________________________________________
Date: Aug 27, 2002
From: John Mireley <glcompair(at)mireley.tcimet.net>
Subject: LPKF ProtoMat 91s
I have access to a LPKF ProtoMat 91s, a computer controlled milling machine for protyping pc boards. Is it worth trying to get the system backup as the hard drive with the drivers and software has been trashed with no backup. -- John Mireley Great Lakes Comp Air 5020 U.S. 20 West Angola, IN 46703 FAX/Voice Mail - 5173323127 Internet - http://198.109.164.162/glcompair ________________________________________________________________________________
From: "Mark Doble" <mark(at)mddesigns.com>
Subject: RFI interference from rs232 line
Date: Aug 27, 2002
Hi List, i have a problem with rfi noise generated from a rs232 line running at 56k. I have a small embedded pc that talks to a engine data board i designed. The boards are stacked on top of each other and connected via a shielded rs232 line. On the radio (Garmin GNS430) from 122.3 to 122.7 i hear a very loud whining which I have isolated to a transmission across this rs232line. If i disconnect the radio antenna the noise disappears...so it is coming through the antenna. i have tried a rf choke (3 of them), better shielding, etc...on the rs232 line. If i stop the rs232 transmission the noise goes away. i plan to use another port on the board to decrease the cable to about 4" from 7"...and add some 0.01uF caps between Tx and Rx to chassis ground...hopefully this will help? thanks for any thoughts..suggestions.. Mark. ________________________________________________________________________________
From: "Bob Verwey" <skymaster(at)icon.co.za>
Subject: Mini-Audio panel
Date: Aug 27, 2002
Any info out there about a circuit and hardware to handle just 2 coms - no speaker? Bob V Beech nut ________________________________________________________________________________
From: jerry(at)tr2.com
Subject: Re: RFI interference from rs232 line
Date: Aug 27, 2002
Mark Doble wrote: > > > On the radio (Garmin GNS430) from 122.3 to 122.7 i hear a very loud whining > which I have isolated to a transmission across this rs232line. If i > disconnect the radio antenna the noise disappears...so it is coming through > the antenna. > > i have tried a rf choke (3 of them), better shielding, etc...on the rs232 > line. > > If i stop the rs232 transmission the noise goes away. *** How about ground loops? Have you thought your grounding through? Specifically, I would take measures to be 100% sure that no RS232 current is passing through the airplane's chassis. One way to do this would be to have one unit have the power & ground connections, and have the other unit obtain power & ground through the first. This approach may not work though, if you have sensors that are grounded. Another thing would be to use an opto-isolated current loop between the two units. A third thing would be - if you know your data rate, you can figure out what rise & fall times you need to get reliable transfer, and limit the speed capability of the RS232 link electronics to that value. 122MHz is, after all, quite fast. Many RS232 chips nowadays have DC-DC converters built in. These use oscillators. But the first thing I'd do is get my grounds in order. If you have a gizmo that produces RF, and you pass some of that RF through the chassis as a current, then the chassis no longer acts as a shield. Rather, it acts as an antenna. If you make sure that none of the RF passes THROUGH the airplane chassis, then the airplane will act as a shield again. - Jerry Kaidor ( jerry(at)tr2.com ) ________________________________________________________________________________
From: "Britt Jensen" <dbjensen(at)thebigmouse.com>
Subject: Shields and Grounds & Ferrite Cores...
Date: Aug 27, 2002
Ok, I have a remedial question. On Garmin prints, they sometimes show a 232 line grounded on both ends - I thought I only needed to tie one end of the shield to ground and leave the other end floating? Also, is there any benefit to putting ferrite cores around the cable bundle near the connectors on back of any given radio? I understand these suppress EMI/RFI quite effectively...If so, do you put it around data, analog and pwr/ground lines, or just data and analog signal lines? Should I use separate cores for power connections versus data/analog? Thanks! Britt '67 Cherokee Six N3950W ________________________________________________________________________________
From: "Phil Birkelbach" <phil(at)petrasoft.net>
Subject: Re: DO-160 Circuit Questions
Date: Aug 27, 2002
Thanks Bob. Try this one... http://phil.petrasoft.net/projects/circuit.jpg Yes they are all DIP parts and desigining for 14V. The LM317 should handle 40V (actually 45V) for life so I may go that route. It adds two resistors and about $0.30 to the project. Would the 10uF cap catch the 300V spike? Or should I add the zener? Never heard of a transorb what is that? How would I go about producing a 300V spike to test all this? The 5V part of the circuit shouldn't be more that 100mA. The motor circuitry could pull up to 2A. Sorry about all the piddley questions but I want to make this right. Godspeed, Phil Birkelbach - Houston Texas RV-7 N727WB (Reserved) http://www.myrv7.com Fuselage Airplanes never win battles with the ground. The best the airplane can hope for is a draw. ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: AeroElectric-List: Re: DO-160 Circuit Questions > > > > > > >Bob and Others, > > > >I am working on a little trim controller circuit and I have a few > >questions concerning how to make this circuit robust enough to survive > >in my airplane. I have posted a circuit drawing at... > >ftp://ftp.w-industries.com/pub/phil/circuit.jpg > > Tried to download this but the page came up "unavailable" . . . > > >Right now I am worried about a couple of things. One are surges and > >spikes. I don't know how well the 7805 will handle these on it's own. > >Should I move up to say an LM317 or will this work okay? I suspect I > >may need some kind of zenner shunt but I know very little about such > >things. > > Assuming you're designing for a 14v airplane, the short term > surge requirement is 40v for, I believe, 100 uSeconds. The > HV versions of the LM317 will handle this. Or, depending on your > current draw, a series resistance in the supply line to the 7805 > followed by a shunt zener or transorb works better yet. This > will cover your 300V spike requirement too. > > > >Also deep down in the control circuit block is an IC that I would like > >to put in a socket so that it can be removed for reprogramming. It is a > >PIC16F73. I have known of a few sockets rejecting their host IC after a > >few years of use/abuse/temperature fluctuations. I suspect that the > >vibration of an airplane would cause the IC to depart the socket in > >fairly short order. > > Not really. Use a good brand of machined pin socket and then > arrange for some simple tie down. I've used a string tie trough > two holes in the board to hold chips in their sockets. Actually, > I think your chips would stay in place without being tied down . . . > but everyone likes a "security blanket". Vibration in airplanes > really isn't as bad as some folks would like us to believe it is. > > > I could use a ZIF socket but if this thing turned > >marketable I would hate to have to add $10 to a $20 circuit for a ZIF > >socket. I am sure that there are some good sockets out there but I > >don't know what to begin to look for. > > I presume were talking about dual in-line pin parts. For > more robust interchangeability during early production, > consider soldering your parts into machined pin sockets > to give them more robust pins. Then plug the assembly into > another socket. This isn't a bad way to go for long term > production for robust, plug-able chips. > > Take a peek at the download problem . . . > > > Bob . . . > > |-------------------------------------------------------| > | There is a great difference between knowing and | > | understanding: you can know a lot about something and | > | not really understand it. -C.F. Kettering- | > |-------------------------------------------------------| > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Matthew Mucker" <matthew(at)mucker.net>
Subject: Mini-Audio panel
Date: Aug 27, 2002
Perhaps Jim Weir's current three-part series in Kitplanes? > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Bob > Verwey > Sent: Tuesday, August 27, 2002 7:58 AM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Mini-Audio panel > > > > > Any info out there about a circuit and hardware to handle just 2 coms - no > speaker? > > Bob V > Beech nut > > http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
From: John Loram <johnl(at)loram.org>
Subject: RFI interference from rs232 line
Date: Aug 27, 2002
Some RS-232 transmitters chips have a pin on which you can place a small capacitor to control the rise and fall time of the output signal. That's the best place to deal with your problem if it really rf. -john- john(at)loram.org www.loram.org -----Original Message----- From: Mark Doble [mailto:mark(at)mddesigns.com] Subject: AeroElectric-List: RFI interference from rs232 line --> Hi List, i have a problem with rfi noise generated from a rs232 line running at 56k. I have a small embedded pc that talks to a engine data board i designed. The boards are stacked on top of each other and connected via a shielded rs232 line. On the radio (Garmin GNS430) from 122.3 to 122.7 i hear a very loud whining which I have isolated to a transmission across this rs232line. If i disconnect the radio antenna the noise disappears...so it is coming through the antenna. i have tried a rf choke (3 of them), better shielding, etc...on the rs232 line. If i stop the rs232 transmission the noise goes away. i plan to use another port on the board to decrease the cable to about 4" from 7"...and add some 0.01uF caps between Tx and Rx to chassis ground...hopefully this will help? thanks for any thoughts..suggestions.. Mark. http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
From: "Bartrim, Todd" <sbartrim(at)mail.canfor.ca>
"'rv-list(at)matronics.com'"
Subject: Torx Screws are here!
Date: Aug 27, 2002
Last week I received a box of 500, 8-32, 100 degree countersunk Torx head screws from MicroFasteners. They were a little pricey by the time I received them up here, north of 49, but they sure look good. I haven't yet replaced all the old Phillips screws, but I expect they will look allot better. No more stripped screw heads! S. Todd Bartrim 13B rotary powered RV-9endurance (finish kit) C-FSTB (reserved) http://www3.telus.net/haywire/RV-9/C-FSTB.htm Torx Screws are here! Last week I received a box of 500, 8-32, 100 degree countersunk Torx head screws from MicroFasteners. They were a little pricey by the time I received them up here, north of 49, but they sure look good. I haven't yet replaced all the old Phillips screws, but I expect they will look allot better. No more stripped screw heads! S. Todd Bartrim 13B rotary powered RV-9endurance (finish kit) C-FSTB (reserved) http://www3.telus.net/haywire/RV-9/C-FSTB.htm ________________________________________________________________________________
From: "Pat Hatch" <pat_hatch(at)msn.com>
Subject: Ammeter Shunt Problem - Very Long
Date: Aug 27, 2002
This is intended as a heads up for those considering the Electronics International volt/ammeter and are wiring their RV per Bob Nuckolls's wiring diagrams where the ammeter shunt is in the alternator output, such as Figure Z-9. I wired my RV-6 this way and had a problem. The first thing I did when I started wiring was to install the voltmeter side of the VA-1A volt/ammeter to the emergency bus so that I could monitor bus voltages as I progressed with the wiring project. When I was finishing wiring, I hooked up the shunt on the firewall and as soon as I did I began to notice strange things. Intermittently, I started to notice that the voltmeter was reading upwards of 20 volts! Now with 12-volt batteries how could this be possible? Stranger yet was when I started flying, all indications were normal. It was only when the engine was shut down that I got the strange indications. I began to consult with one of the engineers at Electronics International, Ron, and we finally got to the root of the problem. I finally determined that the problem was the shunt not being powered, i.e., when there is no voltage across the shunt, the instrument is outside its dynamic range and will not operate properly--plus it is finding a ground through the alternator. This could be a problem under the following scenario: say you are flying along and lose your alternator. No problem, you shut down the alternator and batteries and make sure the emergency bus is powered, right? Well, when you check the emergency bus voltage you are going to find erroneous readings--again, because of the shunt is not being powered. This could be a problem as you attempt to monitor your batteries while you look for a place to land. Well, there is a solution. Maybe this is not the most elegant one, but it is a solution. I wired a DPDT switch to isolate the shunt when the alternator is not operating. So now you have to remember to turn the shunt "OFF" when experiencing alternator failure, or when you want to check battery voltages on the ground prior to starting. Hope this helps somebody down the road. By the way, I love the EI voltmeter, I also have had it in my RV-4 for the past 12 years; however, the shunt is wired in the battery circuit, thus I never saw the problem in the -4. Bob, care to weigh in? Pat Hatch RV-4, N17PH, 700 hrs O-320, Hartzell C/S RV-6, N44PH, 30 hrs O-360, Hartzell C/S Vero Beach, FL ________________________________________________________________________________
Date: Aug 27, 2002
From: John Rourke <john@allied-computer.com>
Subject: A bunch of questions on shielding / grounding
Hi Bob - I think I understand most of the rules of shielding / grounding, but I've got some specifics, perhaps you could help with them... First a review of the rules as I think I understand them, please correct me anywhere I'm mistaken: 1) high-current power lines are best used with the shield being power return, to reduce magnetic EMI. 2) If RF is potentially involved, the shield should be grounded for an electrostatic RF shield, and only at the source end. In such case if protection from magnetic coupling is also needed, twisting the two power lines is desirable (but don't use the shield for power return, as it could carry the RF) Now here's a couple specifics... 1) a Navaid Devices autopilot servo is mounted on a canard pusher, and so has to go about 16 feet... the wires include (2) 18# for power, and (1) 24# for control. I plan to use an 18#/shielded for power and return, and a separate 20#/sh or 22#/sh for the signal, with the shield grounded at the source (instrument panel) (24# just seems too small for anything, especially 16ft when the original app is probably only expecting 4ft or so) Or, could I use 18#twisted-pair/shield all combined together? It probably is best not to, as I think it would actiually take less space for the separate wires (and be easier to pull through the duct) since they aren't twisted, and probably better for shielding the control signal (heard about weird things happening on the AP whenever the radio is transmitting, but that's probably the input wires not the output control signal - do you know?) 2) I have a JPI for CHT/EGT monitoring, and a Grand Rapids for everything else, but it can also do EGT/CHT... since they both use the type-J and type-K thermocouple wiring and load the sensors negligibly, I am told they can share the same sensors. Question - how do I splice them together? Or should I? 3) Does electronic ignition noise (RF) ever make it's way back through the power wiring for the electronic ignition? My unit just uses a single 18#/sh, is that good enough? Or should I use 18#pr/sh? 4) I also have a Weldon electric boost pump - Everyone around here uses 16#pr/shielded, but that seems like overkill, even for 16ft... would 18# be good enough? 5) I'm running all the noisy stuff (strobe power, boost pump power, electronic ignition power, as well as alternator B-lead and magneto P-lead) through a 10-ft copper nduit - will that attenuate any RF enough at the end so that I can use single-conductor shielded power lines for these power lines, rather than shielded twisted-pair? I know that this will likely "depend on the installation", but I'm just curious in your experience with running copper conduit in a glass plane (I recall you did that at least once), if it was still a known problem, or clearly a non-issue, or still an unknown. Thanks much for the lesson! -John ________________________________________________________________________________
From: "Pat Hatch" <pat_hatch(at)msn.com>
Subject: Heads Up - Ground Strap Problem
Date: Aug 27, 2002
I had a problem with my electrical system shortly after I began flying my RV-6. The ground strap that ran from the engine to my firewall ground bus came loose at the crimp on the engine side. Probably because of engine vibration or a loose crimp. The result was that when I attempted to start on a subsequent flight, I noticed that my starter was not as crisp as it had been. I also smelled an odor like burning rubber so I shut down and discovered the problem. When the ground strap came apart, the ground became the carb heat cable and the mixture control cable. The carb heat cable was deformed badly by the heat and the insulation on the mixture control cable was melted. So two new control cables and a second ground strap were ordered. I also soldered all crimps as a backup. Lesson learned: have a backup ground on your engine to prevent damage to your control cables. I noticed that I have two engine grounds on my RV-4, I don't know why I missed the second one on my RV-6! Pat Hatch RV-4, N17PH, 700 hrs O-320, Hartzell C/S RV-6, N44PH, 30 hrs O-360, Hartzell C/S Vero Beach, FL ________________________________________________________________________________
Date: Aug 27, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: DO-160 Circuit Questions
> > >Thanks Bob. Try this one... > >http://phil.petrasoft.net/projects/circuit.jpg > >Yes they are all DIP parts and desigining for 14V. > >The LM317 should handle 40V (actually 45V) for life so I may go that route. >It adds two resistors and about $0.30 to the project. > >Would the 10uF cap catch the 300V spike? Yes, it will . . . > Or should I add the zener? Never >heard of a transorb what is that? Fancy zener with robust junction that's faster than a zener. Not a good voltage regulator but able to withstand high currents for short periods of time. See . . . http://www.gensemi.com/product/protection.htm and http://216.55.140.222/articles/spike.pdf > How would I go about producing a 300V >spike to test all this? Not worth the trouble. I used to have a fixture and found that a decent electrolytic across the input totally wipes it out. Never tested another design on the fixture. >The 5V part of the circuit shouldn't be more that >100mA. The motor circuitry could pull up to 2A. Is your h-bridge good for 40V? If so, then the only thing you need to protect is the low voltage side and if you go to LM317, it can take the 40V barefoot. Just the input capacitor ought to get you covered. >Sorry about all the piddley questions but I want to make this right. No problem. Bob . . . ________________________________________________________________________________
Date: Aug 27, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Berkut N5439N
Okay, little me clean this up a bit. I have the dual electrical, two alternator (60 and 20) installation. I'm running the regulators from B&C I purchased per your drawings four years ago. I'd have to go to the plane to get the numbers. (this reminds me that I'm going to do some "as built" drawings over the next months.) I think I have LR3C-14 regulators from B&C. I have two simple master switches on the panel, I have a breaker for each one. These 5 amp breakers separate the regulator from the power bus which breaks the field and thus takes out the appropriate alternator. The regulator has ov protection. The problem I'm seeing is that the 5 amp breaker is tripping on the AUX side regulator to bus connection. On the ground if I power the system up and turn everything on the breaker doesn't trip. Also in the air the tripping doesn't seem to be caused by turning on or off anything. I think I need to check the small alternator. Also, I'm going to have B&C fax me the troubleshooting sheet for the regulator that I have. I was up in the plane today with the breaker for the AUX bus pulled (this is the same bus to reg breaker that is tripping) and I crossfeed to keep both batteries charged. No problems. Good. The system is offering flexibility like it was designed to do. I'm sure now that the problem is in the small alternator or the regulator or the wiring in between. How long have you had your regulators. Depending on mod level, your regulators MIGHT be overly sensitive to low energy spikes on the bus. Very few airplanes have had any problems but we did make a change to the design about 18 months ago. We could try modifying your regulator to see if that makes the problem go away. It sounds like your aux system is getting a ov nuisance trip. I need to know how to troubleshoot each of them. I know that B&C has a sheet for the regulator. That probably wouldn't be helpful. If the system is operating normally in all respects except for the tripping, then I suspect wiring and the alternator are just fine. You might check for security of the alternator b-lead wiring . . . loose connections here can get you ov nuisance trips. Am I on the right track? Oh, I did check the wires at regulator this morning. They look okay. Good connections. I didn't pull the cowls to look over the small alternator. I will after work Monday. Assuming your regulators are more than 18 months old, how hard is it to pull the aux regulator and send it to me? Bob . . . |-------------------------------------------------------| | There is a great difference between knowing and | | understanding: you can know a lot about something and | | not really understand it. -C.F. Kettering- | |-------------------------------------------------------| ________________________________________________________________________________
From: "Fergus Kyle" <VE3LVO(at)rac.ca>
Subject: Night lighting requirements
Date: Aug 27, 2002
Matt: Subject: Re: AeroElectric-List: anticollision light rqmt (OT?) There seems to be a difference in interpretation of how rules should apply to our aviation activities. " IMHO you give a good appreciation of the divergent attitudes of our colleagues in aircraft building. The discussion on lighting requirements is educating and entertaining (all in one go). However, in this topic we must consider the NEED. As a 35year retiree from driving Big Stuff (and an earlier nightfighter driver) - and having to cope with strange lights on Final at Logan (for one example), I'd really appreciate it if our buddies equip their Super Spaghetti 6's to be as visible to me as is required of any other machine in the air. Too often I've averted centre-punching some devoted instructor/student pair only because I saw them early enough to notice. For me, the lighting of night-flying insects should be homogenous - I prefer not to carry a Rotax in the cockpit to touchdown - unless it's my own. Cheers, Ferg ________________________________________________________________________________
Date: Aug 28, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: A bunch of questions on shielding / grounding
><john@allied-computer.com> > >Hi Bob - > >I think I understand most of the rules of shielding / grounding, but >I've got some specifics, perhaps you could help with them... > >First a review of the rules as I think I understand them, please correct >me anywhere I'm mistaken: > >1) high-current power lines are best used with the shield being power >return, to reduce magnetic EMI. Shielding (in the usual sense of braided copper overlay) has no benefits with respect to magnetic isolation. I built a prop synchronizer once that took advantage of a very strong magnetic field OUTSIDE a shielded spark plug wire. Shielding serves only to break capacitive coupling between adjacent conductors. The best attenuation technique for keeping magnetically coupled noises from propagating is to keep the noisy wires away from potential victims. That's why I like to take the alternator b-lead to the starter contactor out on the firewall and not even bring it into the cockpit. >2) If RF is potentially involved, the shield should be grounded for an >electrostatic RF shield, and only at the source end. In such case if >protection from magnetic coupling is also needed, twisting the two power >lines is desirable (but don't use the shield for power return, as it >could carry the RF) Shielding as a means of containing RF is valid only when the conductor is a nicely matched transmission line . . . like coax cable used for antennas. Fortunately too, the only time we pipe RF around the airplane IS on coaxial cables attached to reasonably matched antennas. This containment of energy is a totally different mode of propagation from electrostatic coupling of fast rise time voltages between parallel conductors. >Now here's a couple specifics... > >1) a Navaid Devices autopilot servo is mounted on a canard pusher, and >so has to go about 16 feet... the wires include (2) 18# for power, and >(1) 24# for control. I plan to use an 18#/shielded for power and return, >and a separate 20#/sh or 22#/sh for the signal, with the shield grounded >at the source (instrument panel) (24# just seems too small for anything, >especially 16ft when the original app is probably only expecting 4ft or so) > >Or, could I use 18#twisted-pair/shield all combined together? It >probably is best not to, as I think it would actiually take less space >for the separate wires (and be easier to pull through the duct) since >they aren't twisted, and probably better for shielding the control >signal (heard about weird things happening on the AP whenever the radio >is transmitting, but that's probably the input wires not the output >control signal - do you know?) Run all wires to and from the servos as a twisted group and don't worry about shielding them. If the servo is sensitive to RF, it's because the servo has some serious, internal design deficiencies and shielding will have marginal if any beneficial effects. In some cases, shielding a non-transmission line signal wire has increased a systems sensitivity to RF rather than decrease it. The RF-Wall has to be at the device's connections to the outside world and should not DEPEND on shielded wire because shielded wire is not dependable in this regard. >2) I have a JPI for CHT/EGT monitoring, and a Grand Rapids for >everything else, but it can also do EGT/CHT... since they both use the >type-J and type-K thermocouple wiring and load the sensors negligibly, I >am told they can share the same sensors. Question - how do I splice them >together? Or should I? Not sure what your question is here. Have you studied the chapter on thermocouples in the book? >3) Does electronic ignition noise (RF) ever make it's way back through >the power wiring for the electronic ignition? My unit just uses a single >18#/sh, is that good enough? Or should I use 18#pr/sh? If it gets out, it will be because the noise is propagating down the center conductor and out into your power distribution system This will require a filter of some variety right at the ignition system . . . again, shielding the wire will be of little if any benefit. >4) I also have a Weldon electric boost pump - Everyone around here uses >16#pr/shielded, but that seems like overkill, even for 16ft... would 18# >be good enough? How much current does it draw? Size the wire for the power handling task. Again, if it's a noisy pump, you're going to need a noise filter at the pump. Ditch the shielded wire. >5) I'm running all the noisy stuff (strobe power, boost pump power, >electronic ignition power, as well as alternator B-lead and magneto >P-lead) through a 10-ft copper nduit - will that attenuate any RF enough >at the end so that I can use single-conductor shielded power lines for >these power lines, rather than shielded twisted-pair? > > I know that this will likely "depend on the installation", but I'm just >curious in your experience with running copper conduit in a glass plane >(I recall you did that at least once), if it was still a known problem, >or clearly a non-issue, or still an unknown. > >Thanks much for the lesson! Hmmm . . . don't think you've read the chapter on noise. Had a guy call me on phone about 10 years ago and gave me a description much like yours. He'd shielded and filtered the bejabbers out of everything. He then asked my advice as to what else he needed. I asked if he had a noise problem. He said, "No, I haven't flown the airplane yet." I had to advise him that he'd spent a lot of time, dollars, weight and worry about things which were probably not going to be problems. And, if they were, they need to be tackled one at a time per the philosophy described in the chapter on noise. Suggest you review that chapter and let's start this conversation over again. Bob . . . ________________________________________________________________________________
Date: Aug 28, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Heads Up - Ground Strap Problem
> >I had a problem with my electrical system shortly after I began flying >my RV-6. The ground strap that ran from the engine to my firewall >ground bus came loose at the crimp on the engine side. Probably because >of engine vibration or a loose crimp. The result was that when I >attempted to start on a subsequent flight, I noticed that my starter was >not as crisp as it had been. I also smelled an odor like burning rubber >so I shut down and discovered the problem. When the ground strap came >apart, the ground became the carb heat cable and the mixture control >cable. The carb heat cable was deformed badly by the heat and the >insulation on the mixture control cable was melted. So two new control >cables and a second ground strap were ordered. I also soldered all >crimps as a backup. See http://216.55.140.222/articles/rules/review.html >Lesson learned: have a backup ground on your engine to prevent damage >to your control cables. I noticed that I have two engine grounds on my >RV-4, I don't know why I missed the second one on my RV-6! Better yet, do a better job on the original ground. What kind of wire were you using for the ground strap? This should be a very flexible, 2AWG equivalent welding cable or flat braid that runs from a brass bolt (to a single point ground block) on firewall to a hefty bolt on the crankcase . . . See chapter on grounding. Your experience has been repeated many, many times by lots of folks over the years. It happened twice in 6 months on the airport I owned by two of my mechanics. Redundancy is not a good substitute for craftsmanship. Multiple grounds only invite noise problems. Bob . . . |-------------------------------------------------------| | There is a great difference between knowing and | | understanding: you can know a lot about something and | | not really understand it. -C.F. Kettering- | |-------------------------------------------------------| ________________________________________________________________________________
Date: Aug 28, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Ammeter Shunt Problem
> >This is intended as a heads up for those considering the Electronics >International volt/ammeter and are wiring their RV per Bob Nuckolls's >wiring diagrams where the ammeter shunt is in the alternator output, >such as Figure Z-9. I wired my RV-6 this way and had a problem. > >The first thing I did when I started wiring was to install the voltmeter >side of the VA-1A volt/ammeter to the emergency bus so that I could >monitor bus voltages as I progressed with the wiring project. When I >was finishing wiring, I hooked up the shunt on the firewall and as soon >as I did I began to notice strange things. Intermittently, I started to >notice that the voltmeter was reading upwards of 20 volts! Now with >12-volt batteries how could this be possible? Stranger yet was when I >started flying, all indications were normal. It was only when the >engine was shut down that I got the strange indications. I began to >consult with one of the engineers at Electronics International, Ron, and >we finally got to the root of the problem. I finally determined that >the problem was the shunt not being powered, i.e., when there is no >voltage across the shunt, the instrument is outside its dynamic range >and will not operate properly--plus it is finding a ground through the >alternator. This could be a problem under the following scenario: say >you are flying along and lose your alternator. No problem, you shut >down the alternator and batteries and make sure the emergency bus is >powered, right? Well, when you check the emergency bus voltage you are >going to find erroneous readings--again, because of the shunt is not >being powered. This could be a problem as you attempt to monitor your >batteries while you look for a place to land. Don't you plan to have enough KNOWN and/or PROVEN capacity on board to make it to airport of intended destination? The voltmeter on the E-bus is a nice thing to have but I would hope it is something that one can easily do without. >Well, there is a solution. Maybe this is not the most elegant one, but >it is a solution. I wired a DPDT switch to isolate the shunt when the >alternator is not operating. So now you have to remember to turn the >shunt "OFF" when experiencing alternator failure, or when you want to >check battery voltages on the ground prior to starting. This is a disappointing feature in the design of their product. Was there no mention of it in their installation manual? If I were to offer such a product to the marketplace, it would be a requirement that ammeter and voltmeter functions be totally independent of each other and non-interactive. >Hope this helps somebody down the road. By the way, I love the EI >voltmeter, I also have had it in my RV-4 for the past 12 years; however, >the shunt is wired in the battery circuit, thus I never saw the problem >in the -4. Bob, care to weigh in? When you use their product in the classic spam-can architecture (borrowed from the 1948 Chevy) then I'm sure the device performs as the manufacturer suggests it should. As soon as you depart from this architecture and for example, want to switch between a variety of shunts and/or switch to measure a variety of voltages on various busses, there comes a time when a certain combination of switch positions yields erroneous results. Too bad. With some simple attention to internal architecture, the product could have been so much more . . . Bob . . . ________________________________________________________________________________
Date: Aug 28, 2002
From: John Rourke <john@allied-computer.com>
Subject: Re: A bunch of questions on shielding / grounding
OK, Bob, I'll start over... I was paraphrasing, in my own words, what I had read in chapters 5 and 16, and as related to my application. I will try to get to the heart of my remaining questions (part of it I have since figured out, both with your help and some additional careful reading), and I will mention the page numbers (mostly from Chapters 5 and 16)... hopefully that should make it clear what I'm asking, even if I don't use exactly the right words! First, remember that I am building a canard-pusher (Velocity) and have long 16' runs. I am running all the antennas down the pilot-side duct, and a 10' by 3/4" copper conduit ground down the co-pilot side, in which I will run the noisy and/or fat wires. For the engine sensor wires (8 thermocouple pair unshielded, and 10 more #22STP (shielded twisted-pair) as per manufacturer instructions), I am running a 5/8" Teflon PTFE tubing, so all wires can be easily removed or added. So, here is what I said before, and what further questions I have: Rule 1: For fat wires, magnetic EMI (as I call it) is usually the big issue as I understand it. (This is also your item (2b) on page 16-8.) According to pages 5-8 ("A conduit-shielded bundle which uses the shield for its ground connection has very small magnetic shields around it") and 5-9 ("Single-conductor shielded wire may be considered for things like compass lights, instrument floods, pannel dimmer rheostats, etc. Use the shield as the return conductor!"), I can minimize magnetic EMI either by using the shield as a return conductor, or by twisting the ground and power leads around each other. In your reply, you said: "Shielding (in the usual sense of braided copper overlay) has no benefits with respect to magnetic isolation. I built a prop synchronizer once that took advantage of a very strong magnetic field OUTSIDE a shielded spark plug wire. Shielding serves only to break capacitive coupling between adjacent conductors. The best attenuation technique for keeping magnetically coupled noises from propagating is to keep the noisy wires away from potential victims." But I'm talking about the power/ground circuits, not a spark plug type situation. Perhaps I didn't make that clear? Also, although I know that using single-conductor shielded wire inside a ground conduit does not provide any extra magnetic shielding advantages, it is more compact (I believe) to run such smooth wire rather than lumpy twisted wire, and is much eaiser to pull through the conduit. The power/ground pairs where I propose to employ this method include: Fuel pump(#16), autopilot servo power(#18), electronic ignition power(#18), Strobe power (#18), and navlight power(#18), which will accompany the alternator field lead(#18), alternator B-lead(#8) and magneto P-lead(#18/sh) all in the copper conduit. (I just realized now, that very likely I really don't need *any* of those shields for ground return inside the conduit, if I use the conduit itself as the ground return - I was focusing on single point grounding up front, but you clearly have stated in the book that having a second ground block in the engine area is OK. So, if I only put pwer wires in the conduit where the ground return circuit is the conduit itself, do I still have to twist them? I don't think so, and it is certainly easier to pull them if not.) Rule #2: Shielding, for shielding's sake (and not to provide a return path for a power circuit), is only good for limited RF protection, and practically none from capacitive coupling in long parallel lines. I interpreted RFI as being all fast-rise-time signals, and that that protection was significant. Am I mistaken on both counts? In your reply, you said: "Shielding as a means of containing RF is valid only when the conductor is a nicely matched transmission line . . . like coax cable used for antennas. Fortunately too, the only time we pipe RF around the airplane IS on coaxial cables attached to reasonably matched antennas. This containment of energy is a totally different mode of propagation from electrostatic coupling of fast rise time voltages between parallel conductors." I did not know that. (I just got off the phone with a guy at Navaid Devices, and he too was under the impression that shielding worked against capacitive coupling - but he also freely admitted that shielding issues are still something of a "black art" to him.) Does that mean that having the noisy wires in the copper conduit will not attenuate any fast-rise-time signals? (I guess you've said that many times, it's just contrary to what I thought I knew.) Although that was not my primary reason for routing the noisy wires there, I was hoping it would help... in any event, it can't hurt, can it? As for my specific questions, I've got them pretty much handled - As for the fuel pump, it is around 5 amps so #16 seems like waaay overkill for 14 ft... the problem was, I think, that there were several pump failures locally where the installation was blamed (and warranty therefore voided), and #18 was picked for the culprit, and #16 for the solution. Since I'm running it through the conduit anyway, I'll forget about the shielding and just run #18 and check the voltage at the pump... it looks like we're talking about 0.45 Vdrop for #18 instead of 0.28 Vdrop for #16 - I can't imagine that would be a problem. I guess it really is pretty simple: 1) Fat wires are magnetically noisy, which can be counteracted by keeping the power/ground pairs together, or power contained within the ground return 2) Capacitive coupling will still be a problem even with shields; the only way to avoid that is to keep the noisy wires well-separated from the sensitive ones (mostly audio, or radio antennas) 3) RF noise (or audio noise, for that matter) on power lines is best handled by filters at either the source or the destination depending on symptoms, but only if necessary. 4) For audio circuits, first keep them away from fat wires; second use twisted pair; third if shielded, connect shielding only at one end (intercom or radio). I do have one new question: should I put my (not-terribly-sensitive-but-could-be) engine sensor wires in the co-pilot duct next to the conduit with the fat and/or noisy wires, or should I put them in the pilot duct with the antenna coax (RG400)? The only problems I anticipate are the autopilot servo wires, and since all problems so far (on other planes) have been demonstrated only during radio transmission, I will keep those away from the antenna cables. I'm just wondering about the others at this point. I hope this makes more sense. At least, I *think* I'm making progress! Shielding and grounding has been a "black art" for me as well, for too long, and I hope this exchange will illuminate things more than confuse them further. -John ________________________________________________________________________________
Date: Aug 28, 2002
From: "Andy Karmy" <andy(at)karmy.com>
Subject: Re: Push to Start Button Circuit - Follow Up
Speaking of Start buttons, what do you all think about using a momentary SPST switch as a start button? I have the push button with guard from Aeroelectric, however I'm thinking it would be kind of neat to use one of those red switch guards that flips up when you use the device... Seems I would have to drill it out a bit to fit the push button inside, so I am considering going to a spring loaded switch inside the guard. So starting would be: Flip up the cover, flip up both mags and hit the switch to flip blades... - Andy Karmy RV9A - Seattle WA Wiring... ---------- Original Message ---------------------------------- > whether or not your contactor has a built in spike catcher > diode. If not, be sure to add one externally. The intermittent > duty contactor can really EAT starter buttons. > > Bob . . . ________________________________________________________________________________
Date: Aug 28, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: A bunch of questions on shielding / grounding
><john@allied-computer.com> > > OK, Bob, I'll start over... I was paraphrasing, in my own words, what >I had read in chapters 5 and 16, and as related to my application. I >will try to get to the heart of my remaining questions (part of it I >have since figured out, both with your help and some additional careful >reading), and I will mention the page numbers (mostly from Chapters 5 >and 16)... hopefully that should make it clear what I'm asking, even if >I don't use exactly the right words! > >First, remember that I am building a canard-pusher (Velocity) and have >long 16' runs. I am running all the antennas down the pilot-side duct, >and a 10' by 3/4" copper conduit ground down the co-pilot side, in which >I will run the noisy and/or fat wires. For the engine sensor wires (8 >thermocouple pair unshielded, and 10 more #22STP (shielded twisted-pair) >as per manufacturer instructions), I am running a 5/8" Teflon PTFE >tubing, so all wires can be easily removed or added. I'd run these down the conduit too. >So, here is what I said before, and what further questions I have: > >Rule 1: For fat wires, magnetic EMI (as I call it) is usually the big >issue as I understand it. (This is also your item (2b) on page 16-8.) >According to pages 5-8 ("A conduit-shielded bundle which uses the shield >for its ground connection has very small magnetic shields around it") >and 5-9 ("Single-conductor shielded wire may be considered for things >like compass lights, instrument floods, pannel dimmer rheostats, etc. >Use the shield as the return conductor!"), I can minimize magnetic EMI >either by using the shield as a return conductor, or by twisting the >ground and power leads around each other. Okay, once you run things down the conduit wherein the conduit is also ground return for everything aft, the coaxial conductor benefits for reducing radiated magnetically coupled noises is covered. Closely paralleled current flows, twisted pair paralleled current flows and coaxial paired current flows are all strong attenuators of magnetic field radiation as a result of any of those currents. I think you've got it well covered. >In your reply, you said: > > "Shielding (in the usual sense of braided copper overlay) > has no benefits with respect to magnetic isolation. I built > a prop synchronizer once that took advantage of a very strong > magnetic field OUTSIDE a shielded spark plug wire. Shielding > serves only to break capacitive coupling between adjacent > conductors. The best attenuation technique for keeping magnetically > coupled noises from propagating is to keep the noisy wires > away from potential victims." > > >But I'm talking about the power/ground circuits, not a spark plug type >situation. Perhaps I didn't make that clear? Also, although I know that >using single-conductor shielded wire inside a ground conduit does not >provide any extra magnetic shielding advantages, it is more compact (I >believe) to run such smooth wire rather than lumpy twisted wire, and is >much eaiser to pull through the conduit. The power/ground pairs where I >propose to employ this method include: Fuel pump(#16), autopilot servo >power(#18), electronic ignition power(#18), Strobe power (#18), and >navlight power(#18), which will accompany the alternator field >lead(#18), alternator B-lead(#8) and magneto P-lead(#18/sh) all in the >copper conduit. > >(I just realized now, that very likely I really don't need *any* of >those shields for ground return inside the conduit, if I use the conduit >itself as the ground return - I was focusing on single point grounding >up front, but you clearly have stated in the book that having a second >ground block in the engine area is OK. So, if I only put pwer wires in >the conduit where the ground return circuit is the conduit itself, do I >still have to twist them? I don't think so, You are correct. Once magnetically contained within the conduit, no additional treatment such as twisting and/or shielding is necessary . . . EXCEPT p-leads from mags DO have very fast rise-time voltages on them and they WILL benefit from shielding. All of these wires can come down the same tube. > and it is certainly easier to pull them if not.) You bet. >Rule #2: Shielding, for shielding's sake (and not to provide a return >path for a power circuit), is only good for limited RF protection, and >practically none from capacitive coupling in long parallel lines. > >I interpreted RFI as being all fast-rise-time signals, and that that >protection was significant. Am I mistaken on both counts? In your reply, >you said: > > "Shielding as a means of containing RF is valid only when > the conductor is a nicely matched transmission line . . . like > coax cable used for antennas. Fortunately too, the only time > we pipe RF around the airplane IS on coaxial cables attached > to reasonably matched antennas. This containment of energy > is a totally different mode of propagation from electrostatic > coupling of fast rise time voltages between parallel conductors." > >I did not know that. (I just got off the phone with a guy at Navaid >Devices, and he too was under the impression that shielding worked >against capacitive coupling - but he also freely admitted that shielding >issues are still something of a "black art" to him.) Does that mean that >having the noisy wires in the copper conduit will not attenuate any >fast-rise-time signals? It keeps them INSIDE the conduit but in the case of strong noises like p-leads, you need to keep the noise from propagating to other wires inside the conduit hence the value of shielding these wires. RF is fast rise time, obviously, but if carried from one place to another on transmission lines with good matching, then the signals are totally contained in the coax . . . and equally invulnerable to external stresses. Shielding power and signal wires can have an effect on RF coupling into or out of wires . . . but it can be BAD as well as good. This is because the wire tries to behave as a coaxial transmission line but it's NEVER matched for low SWR . . . hence the risk of causing as much problem as it fixes. > (I guess you've said that many times, it's just >contrary to what I thought I knew.) Although that was not my primary >reason for routing the noisy wires there, I was hoping it would help... >in any event, it can't hurt, can it? Only rare cases of RF coupling does shielding hurt. In all other cases it can range from benign benefits to profound as long as the rules for ground-loop avoidance are observed. >As for my specific questions, I've got them pretty much handled - As for >the fuel pump, it is around 5 amps so #16 seems like waaay overkill for >14 ft... the problem was, I think, that there were several pump failures >locally where the installation was blamed (and warranty therefore >voided), and #18 was picked for the culprit, and #16 for the >solution. Since I'm running it through the conduit anyway, I'll forget >about the shielding and just run #18 and check the voltage at the >pump... it looks like we're talking about 0.45 Vdrop for #18 instead of >0.28 Vdrop for #16 - I can't imagine that would be a problem. I agree. Do you know what kind of words the supplier used with respect to "improper installation" for which they claimed damage to the product? I can't imagine that low voltage would do anything to a pump other than degrade its performance. It would be interesting to hear their rational. >I guess it really is pretty simple: >1) Fat wires are magnetically noisy, which can be counteracted by >keeping the power/ground pairs together, or power contained within the >ground return Yup. >2) Capacitive coupling will still be a problem even with shields; the >only way to avoid that is to keep the noisy wires well-separated from >the sensitive ones (mostly audio, or radio antennas). I've seen p-leads reside in friendly proximity with audio leads . . . as long as the p-leads get airframe grounded at engine end only. Antenna coaxes should be completely benign with respect to co-location issues when you use modern coax (RG-142/400). >3) RF noise (or audio noise, for that matter) on power lines is best >handled by filters at either the source or the destination depending on >symptoms, but only if necessary. Yup. >4) For audio circuits, first keep them away from fat wires; second use >twisted pair; third if shielded, connect shielding only at one end >(intercom or radio). . . . unless specifically shown to be something different in the manufacturer's installation instructions. >I do have one new question: should I put my >(not-terribly-sensitive-but-could-be) engine sensor wires in the >co-pilot duct next to the conduit with the fat and/or noisy wires, or >should I put them in the pilot duct with the antenna coax (RG400)? The >only problems I anticipate are the autopilot servo wires, and since all >problems so far (on other planes) have been demonstrated only during >radio transmission, I will keep those away from the antenna cables. I'm >just wondering about the others at this point. I think you have a greater chance of having trouble by having two routes for wires running down both sides of fuselage than by bringing them all down the same side. "sensitive" wires could be outside the conduit but I'd still run everything down the same side. >I hope this makes more sense. At least, I *think* I'm making progress! >Shielding and grounding has been a "black art" for me as well, for too >long, and I hope this exchange will illuminate things more than confuse >them further. You understand more than what I deduced from your original post. You're on the right track. Bob . . . ________________________________________________________________________________
From: BobsV35B(at)aol.com
Date: Aug 28, 2002
Subject: Re: A bunch of questions on shielding / grounding
In a message dated 8/28/02 3:30:46 PM Central Daylight Time, bob.nuckolls(at)cox.net writes: > EXCEPT p-leads from mags DO have very fast rise-time > voltages on them and they WILL benefit from shielding. All of these > wires can come down the same tube. > Good Afternoon Bob, I know this has been plain to most, but I must have missed something somewhere. Should the shielding on P-leads be grounded at both ends or just one? Which end is best if it is to be only one? Happy Skies, Old Bob ________________________________________________________________________________
From: "Rob Housman" <RobH@hyperion-ef.com>
Subject: Re: A bunch of questions on shielding / grounding
Date: Aug 28, 2002
In your response you said that it would be better not to have multiple paths. This seems counterintuitive. Would you please explain briefly why you recommend not having wires on both sides of the fuselage (it isn't too late for me to re-route the antenna coax on my Europa). Best regards, Rob Housman -----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: AeroElectric-List: Re: A bunch of questions on shielding / grounding ><john@allied-computer.com> > >I do have one new question: should I put my >(not-terribly-sensitive-but-could-be) engine sensor wires in the >co-pilot duct next to the conduit with the fat and/or noisy wires, or >should I put them in the pilot duct with the antenna coax (RG400)? The >only problems I anticipate are the autopilot servo wires, and since all >problems so far (on other planes) have been demonstrated only during >radio transmission, I will keep those away from the antenna cables. I'm >just wondering about the others at this point. I think you have a greater chance of having trouble by having two routes for wires running down both sides of fuselage than by bringing them all down the same side. "sensitive" wires could be outside the conduit but I'd still run everything down the same side. >I hope this makes more sense. At least, I *think* I'm making progress! >Shielding and grounding has been a "black art" for me as well, for too >long, and I hope this exchange will illuminate things more than confuse >them further. You understand more than what I deduced from your original post. You're on the right track. Bob . . . http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
Date: Aug 28, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Push to Start Button Circuit - Follow Up
> >Speaking of Start buttons, what do you all think about using a momentary >SPST switch as a start button? > >I have the push button with guard from Aeroelectric, however I'm thinking >it would be kind of neat to use one of those red switch guards that flips >up when you use the device... Seems I would have to drill it out a bit to >fit the push button inside, so I am considering going to a spring loaded >switch inside the guard. > >So starting would be: Flip up the cover, flip up both mags and hit the >switch to flip blades... That's been done. I've also seen a customer use 2-5 series switches so that the starter is engaged by raising one of the mag switches to the full up position. This combines ignition and starter functions into two switches. Why guarded? If your panel is laid out well, chances of inadvertent operation is nil. Bob . . . ________________________________________________________________________________
From: mprather(at)spro.net
Subject: Re: A bunch of questions on shielding /
grounding
Date: Aug 28, 2002
The p-lead should be grounded to the mag (engine) only. The high frequency (engergy) pulses that come up the center conductor of the p-lead are coupled to its shield because of the length of the parallel run of the conductors (coaxial). If you connect the p-lead shield to some other ground at the panel, this coupled noise gets injected into the ground at that point. This ground noise can be picked up by any piece of equipment that is also grounded to the same place. There is no possible benefit from grounding the p-lead to the panel. That's my understanding, anyway. ----- Original Message ----- From: BobsV35B(at)aol.com Date: Wednesday, August 28, 2002 2:50 pm Subject: Re: AeroElectric-List: Re: A bunch of questions on shielding / grounding > > In a message dated 8/28/02 3:30:46 PM Central Daylight Time, > bob.nuckolls(at)cox.net writes: > > > > EXCEPT p-leads from mags DO have very fast rise-time > > voltages on them and they WILL benefit from shielding. All of > these> wires can come down the same tube. > > > > Good Afternoon Bob, > > I know this has been plain to most, but I must have missed > something > somewhere. > > Should the shielding on P-leads be grounded at both ends or just > one? Which > end is best if it is to be only one? > > Happy Skies, > > Old Bob > > ________________________________________________________________________________
From: mprather(at)spro.net
Subject: Re: A bunch of questions on
shielding / grounding
Date: Aug 28, 2002
The issue with multiple ground paths is called ground loop. The voltage of the ground wire at the ground terminal of a high current /high noise device will not necessarily be 0 volts. This is so because when that device is using a lot of power, the same amount of current is being carried by both the power and ground leads. The current being carried in the wires will raise the voltage at the ground connection of the device, and lower it at the 12V connection. If a device uses 10A of current, and its wired using the same size wire for both power and ground, the voltage drop caused by the wire's resistance will be shared by both leads. If you have 0.1ohm total resistance (to make the math easy), then the total voltage drop is 1V, .5v on the ground and .5V on the V+. No problem so far. However, if another device has its own power and ground wires, but ALSO has a short ground path to the power hog, the power hog will also start moving around the ground potential for the more delicate/sensitive device. Its no big deal for light bulbs, and electric motors, because they won't have their performance affected significantly. But it could cause you headaches in your intercom (pun intended). That changing ground potential would be just as bad as wiggling the V+ lead by the same amount. No amount of filtering or shielding will fix this. The question with where to ground an antenna's coax is a slightly different one. The reason is that antennas are transmitting at (and optimized for) a frequency where some motor or alternator induced noise will have little effect. So, if you have a dipole with a ground plane, the feed line's shield obviously needs to be connected to that ground plane and (with the coax connector) to the radio chassis. If the ground plane is shorted to the ground of a power hog (because you have a metal plane for ex), there may not be much you can do about it, but it probably won't cause you any problems. BTW, the ground plane doesn't really need to be at the same ground as the battery (no need to run a ground wire from the battery to the ground plane in a plastic airplane), because the ground plane is just being used to 'fool' the antenna into thinking it has a bottom half (for a dipole). From the high frequency, EM standpoint, they look the same. Matt- ----- Original Message ----- From: "Rob Housman" <RobH@hyperion-ef.com> Date: Wednesday, August 28, 2002 3:08 pm Subject: RE: AeroElectric-List: Re: A bunch of questions on shielding / grounding > <RobH@hyperion-ef.com> > > In your response you said that it would be better not to have multiple > paths. This seems counterintuitive. Would you please explain > briefly why > you recommend not having wires on both sides of the fuselage (it > isn't too > late for me to re-route the antenna coax on my Europa). > > Best regards, > > Rob Housman > > -----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: AeroElectric-List: Re: A bunch of questions on shielding / > grounding > > > > ><john@allied-computer.com> > > > > > > >I do have one new question: should I put my > >(not-terribly-sensitive-but-could-be) engine sensor wires in the > >co-pilot duct next to the conduit with the fat and/or noisy wires, or > >should I put them in the pilot duct with the antenna coax (RG400)? > The>only problems I anticipate are the autopilot servo wires, and > since all > >problems so far (on other planes) have been demonstrated only during > >radio transmission, I will keep those away from the antenna > cables. I'm > >just wondering about the others at this point. > > I think you have a greater chance of having trouble by having two > routes for wires running down both sides of fuselage than by > bringing them all down the same side. "sensitive" wires could > be outside the conduit but I'd still run everything down the > same side. > > > >I hope this makes more sense. At least, I *think* I'm making > progress!>Shielding and grounding has been a "black art" for me as > well, for too > >long, and I hope this exchange will illuminate things more than > confuse>them further. > You understand more than what I deduced from your > original post. You're on the right track. > > Bob . . . > ________________________________________________________________________________
From: "Larry Bowen" <Larry(at)BowenAero.com>
Subject: Re: Push to Start Button Circuit - Follow Up
Date: Aug 28, 2002
Why? Because guarded switches look cool! I know it's a shallow and silly reason, but my plane, my perogative. RE: the 2-5 switch, so if I had a "one mag and one Jeff Rose EI" arrangement, I could use this switch to ensure the EI is not engaged while cranking, and put it on line as soon as the starter is disengaged. Right? Like this: OFF - EI ON - (STARTER ON)? That would be a nice arrangement. Any drawbacks? - Larry Bowen Larry(at)BowenAero.com http://BowenAero.com > -----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 > Sent: Wednesday, August 28, 2002 5:16 PM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Re: Push to Start Button Circuit > - Follow Up > > > --> > > > > > >Speaking of Start buttons, what do you all think about using a > >momentary > >SPST switch as a start button? > > > >I have the push button with guard from Aeroelectric, however I'm > >thinking > >it would be kind of neat to use one of those red switch > guards that flips > >up when you use the device... Seems I would have to drill it > out a bit to > >fit the push button inside, so I am considering going to a > spring loaded > >switch inside the guard. > > > >So starting would be: Flip up the cover, flip up both mags > and hit the > >switch to flip blades... > > That's been done. I've also seen a customer use > 2-5 series switches so that the starter is engaged > by raising one of the mag switches to the full up > position. This combines ignition and starter functions > into two switches. Why guarded? If your panel is > laid out well, chances of inadvertent operation is > nil. > > Bob . . . ________________________________________________________________________________
Date: Aug 28, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: RE: Push to Start Button Circuit - Follow Up
> > > That's been done. I've also seen a customer use > > 2-5 series switches so that the starter is engaged > > by raising one of the mag switches to the full up > > position. This combines ignition and starter functions > > into two switches. Why guarded? If your panel is > > laid out well, chances of inadvertent operation is > > nil. > > > >Yeah, but switch guards look damned cool on the panel! :) Can't argue with esthetics! Bob . . . ________________________________________________________________________________
Date: Aug 29, 2002
From: John Rourke <john@allied-computer.com>
Subject: Re: A bunch of questions on shielding / grounding
Hi Rob, I believe he was referring specifically to my questions of where to run the engine sensor wires - if I run them in the same duct with the antenna coax, that by itself is not an issue, but there will be a greater likelihood of ground loops, or at least ground differentials between the grounded wires down the pilot duct compared to the grounded wires running down the co-pilot duct simply because they experience a different electrical environment, in addition to probably being a different length. When you run power, ground, sensor and control wires all together, their grounds are much more likely to be all at approximately the same level, which is a good thing when trying to avoid ground loops.(This however is unrelated to the antenna lines, as they are in a completely different circuit segment) As for the group of antenna coax feedlines themselves, properly installed cable (especially the double-shielded RG400 or RG142) probably could coexist with noisy and sensitive wires (if they have all the proper protections in place), but it is always a good idea to keep them as far away as possible. (Bob, feel free to step in and add or subtract anything, but I am pretty sure I understood your intent and I thought I'd return a favor a bit, and save you some typing!) -John Rob Housman wrote: > >In your response you said that it would be better not to have multiple >paths. This seems counterintuitive. Would you please explain briefly why >you recommend not having wires on both sides of the fuselage (it isn't too >late for me to re-route the antenna coax on my Europa). > >Best regards, > >Rob Housman > > > > > >><john@allied-computer.com> >> > > > >>I do have one new question: should I put my >>(not-terribly-sensitive-but-could-be) engine sensor wires in the >>co-pilot duct next to the conduit with the fat and/or noisy wires, or >>should I put them in the pilot duct with the antenna coax (RG400)? The >>only problems I anticipate are the autopilot servo wires, and since all >>problems so far (on other planes) have been demonstrated only during >>radio transmission, I will keep those away from the antenna cables. I'm >>just wondering about the others at this point. >> > > I think you have a greater chance of having trouble by having two > routes for wires running down both sides of fuselage than by > bringing them all down the same side. "sensitive" wires could > be outside the conduit but I'd still run everything down the > same side. > ________________________________________________________________________________
From: "Sam Chambers" <schamber@glasgow-ky.com>
Subject: Re: Push to Start Button Circuit - Follow Up
Date: Aug 28, 2002
Andy, I am using an Eaton/Cutler-Hammer momentary contact Mil-spec SPST switch for this function. I was going to use the red safety covers for the mag, elect. ign, start, bat and alt switches, but didn't like the way they looked on my panel. I have five of them. They are the MS25224-1 as shown in the AS & S catalog at $9.10 each. I would sell all of them for $30.00. Let me know. Thanks, Sam Chambers schamber@glasgow-ky.com ----- Original Message ----- From: "Andy Karmy" <andy(at)karmy.com> Subject: Re: AeroElectric-List: Re: Push to Start Button Circuit - Follow Up > > Speaking of Start buttons, what do you all think about using a momentary SPST switch as a start button? > > I have the push button with guard from Aeroelectric, however I'm thinking it would be kind of neat to use one of those red switch guards that flips up when you use the device... Seems I would have to drill it out a bit to fit the push button inside, so I am considering going to a spring loaded switch inside the guard. > > So starting would be: Flip up the cover, flip up both mags and hit the switch to flip blades... > > - Andy Karmy > RV9A - Seattle WA > Wiring... > > ---------- Original Message ---------------------------------- > > whether or not your contactor has a built in spike catcher > > diode. If not, be sure to add one externally. The intermittent > > duty contactor can really EAT starter buttons. > > > > Bob . . . > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
Date: Aug 29, 2002
From: John Rourke <john@allied-computer.com>
Subject: Re: Push to Start Button Circuit - Follow Up
Actually, Jeff Rose's EI is designed to be on while cranking, and reportedly makes for a smoother start. Check your model and see what it recommends, but for mine it will be on during cranking. -John Larry Bowen wrote: > >Why? Because guarded switches look cool! I know it's a shallow and >silly reason, but my plane, my perogative. > >RE: the 2-5 switch, so if I had a "one mag and one Jeff Rose EI" >arrangement, I could use this switch to ensure the EI is not engaged >while cranking, and put it on line as soon as the starter is disengaged. >Right? Like this: OFF - EI ON - (STARTER ON)? That would be a nice >arrangement. Any drawbacks? > >- >Larry Bowen >Larry(at)BowenAero.com >http://BowenAero.com > > >>-----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 >>Sent: Wednesday, August 28, 2002 5:16 PM >>To: aeroelectric-list(at)matronics.com >>Subject: AeroElectric-List: Re: Push to Start Button Circuit >>- Follow Up >> >> >>--> >> >> >>> >> >> >>>Speaking of Start buttons, what do you all think about using a >>>momentary >>>SPST switch as a start button? >>> >>>I have the push button with guard from Aeroelectric, however I'm >>>thinking >>>it would be kind of neat to use one of those red switch >>> >>guards that flips >> >>>up when you use the device... Seems I would have to drill it >>> >>out a bit to >> >>>fit the push button inside, so I am considering going to a >>> >>spring loaded >> >>>switch inside the guard. >>> >>>So starting would be: Flip up the cover, flip up both mags >>> >>and hit the >> >>>switch to flip blades... >>> >> That's been done. I've also seen a customer use >> 2-5 series switches so that the starter is engaged >> by raising one of the mag switches to the full up >> position. This combines ignition and starter functions >> into two switches. Why guarded? If your panel is >> laid out well, chances of inadvertent operation is >> nil. >> >> Bob . . . >> > > ________________________________________________________________________________
From: "Larry Bowen" <Larry(at)BowenAero.com>
Subject: Re: Push to Start Button Circuit - Follow Up
Date: Aug 29, 2002
Excellent. I didn't know -- I haven't ordered it yet. Soon. You got your through the Orndorfs? - Larry Bowen Larry(at)BowenAero.com http://BowenAero.com > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of John Rourke > Sent: Thursday, August 29, 2002 2:24 AM > To: aeroelectric-list(at)matronics.com > Subject: Re: AeroElectric-List: Re: Push to Start Button > Circuit - Follow Up > > > --> <john@allied-computer.com> > > Actually, Jeff Rose's EI is designed to be on while cranking, and > reportedly makes for a smoother start. Check your model and > see what it > recommends, but for mine it will be on during cranking. > > -John > > > Larry Bowen wrote: > > >--> > > > >Why? Because guarded switches look cool! I know it's a shallow and > >silly reason, but my plane, my perogative. > > > >RE: the 2-5 switch, so if I had a "one mag and one Jeff Rose EI" > >arrangement, I could use this switch to ensure the EI is not engaged > >while cranking, and put it on line as soon as the starter is > >disengaged. Right? Like this: OFF - EI ON - (STARTER ON)? > That would > >be a nice arrangement. Any drawbacks? > > > >- > >Larry Bowen > >Larry(at)BowenAero.com > >http://BowenAero.com > > > > > >>-----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 > >>Sent: Wednesday, August 28, 2002 5:16 PM > >>To: aeroelectric-list(at)matronics.com > >>Subject: AeroElectric-List: Re: Push to Start Button Circuit > >>- Follow Up > >> > >> > >>--> > >> > >> > >>> > >> > >> > >>>Speaking of Start buttons, what do you all think about using a > >>>momentary > >>>SPST switch as a start button? > >>> > >>>I have the push button with guard from Aeroelectric, however I'm > >>>thinking > >>>it would be kind of neat to use one of those red switch > >>> > >>guards that flips > >> > >>>up when you use the device... Seems I would have to drill it > >>> > >>out a bit to > >> > >>>fit the push button inside, so I am considering going to a > >>> > >>spring loaded > >> > >>>switch inside the guard. > >>> > >>>So starting would be: Flip up the cover, flip up both mags > >>> > >>and hit the > >> > >>>switch to flip blades... > >>> > >> That's been done. I've also seen a customer use > >> 2-5 series switches so that the starter is engaged > >> by raising one of the mag switches to the full up > >> position. This combines ignition and starter functions > >> into two switches. Why guarded? If your panel is > >> laid out well, chances of inadvertent operation is > >> nil. > >> > >> Bob . . . > >> > > > > > > > =========== > =========== > =========== > Search Engine: > http://www.matronics.com/search > =========== > > > ________________________________________________________________________________
Date: Aug 29, 2002
From: John Rourke <john@allied-computer.com>
Subject: Re: Push to Start Button Circuit - Follow Up
My engine builder got it (Don George, in Orlando). I've got all the manuals, it expalins everything quite clearly. -John Larry Bowen wrote: > >Excellent. I didn't know -- I haven't ordered it yet. Soon. You got >your through the Orndorfs? > >- >Larry Bowen >Larry(at)BowenAero.com >http://BowenAero.com > > >>-----Original Message----- >>From: owner-aeroelectric-list-server(at)matronics.com >>[mailto:owner-aeroelectric-list-server(at)matronics.com] On >>Behalf Of John Rourke >>Sent: Thursday, August 29, 2002 2:24 AM >>To: aeroelectric-list(at)matronics.com >>Subject: Re: AeroElectric-List: Re: Push to Start Button >>Circuit - Follow Up >> >> >>--> <john@allied-computer.com> >> >>Actually, Jeff Rose's EI is designed to be on while cranking, and >>reportedly makes for a smoother start. Check your model and >>see what it >>recommends, but for mine it will be on during cranking. >> >>-John >> >> >>Larry Bowen wrote: >> >>>--> >>> >>>Why? Because guarded switches look cool! I know it's a shallow and >>>silly reason, but my plane, my perogative. >>> >>>RE: the 2-5 switch, so if I had a "one mag and one Jeff Rose EI" >>>arrangement, I could use this switch to ensure the EI is not engaged >>>while cranking, and put it on line as soon as the starter is >>>disengaged. Right? Like this: OFF - EI ON - (STARTER ON)? >>> >>That would >> >>>be a nice arrangement. Any drawbacks? >>> >>>- >>>Larry Bowen >>>Larry(at)BowenAero.com >>>http://BowenAero.com >>> >>> >>>>-----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 >>>>Sent: Wednesday, August 28, 2002 5:16 PM >>>>To: aeroelectric-list(at)matronics.com >>>>Subject: AeroElectric-List: Re: Push to Start Button Circuit >>>>- Follow Up >>>> >>>> >>>>--> >>>> >>>> >>>>> >>>> >>>> >>>>>Speaking of Start buttons, what do you all think about using a >>>>>momentary >>>>>SPST switch as a start button? >>>>> >>>>>I have the push button with guard from Aeroelectric, however I'm >>>>>thinking >>>>>it would be kind of neat to use one of those red switch >>>>> >>>>guards that flips >>>> >>>>>up when you use the device... Seems I would have to drill it >>>>> >>>>out a bit to >>>> >>>>>fit the push button inside, so I am considering going to a >>>>> >>>>spring loaded >>>> >>>>>switch inside the guard. >>>>> >>>>>So starting would be: Flip up the cover, flip up both mags >>>>> >>>>and hit the >>>> >>>>>switch to flip blades... >>>>> >>>> That's been done. I've also seen a customer use >>>> 2-5 series switches so that the starter is engaged >>>> by raising one of the mag switches to the full up >>>> position. This combines ignition and starter functions >>>> into two switches. Why guarded? If your panel is >>>> laid out well, chances of inadvertent operation is >>>> nil. >>>> >>>> Bob . . . >>>> >>> >> >>=========== >>=========== >>=========== >> Search Engine: >>http://www.matronics.com/search >>=========== >> >> >> > > ________________________________________________________________________________
From: Villi Seemann <villi.seemann(at)nordea.com>
Subject: Re: AeroElectric-List Digest: 20 Msgs - 08/25/02
Date: Aug 29, 2002
> > >In the pure analog world, you'll to switch > > > between 14 and 18 wires from the indicator to the two radios. > > > This take a 18 pole, double throw switch . . . > > > >Could this be an application for those old computer printer switches? They > >switch 25 inputs to either of 25 outputs. > It might not work if it was for a printer, but old RS.232 seral communication devices needed most of the 25 wires switched in an A-B switch - except pin-7 which usually is common for RS-232 connections, and was connected from the input to both of the outputs. Bear in mind that these switches are designed for low power signal (+/- 12 V few mAmps). They will not carry or break any significan amount of power. Regards Villi H. Seemann Senior Engineer Infrastructure Network Phone (+45) 3333 2101 FAX (+45) 3333 1130 CellPhn (+45)2220 7690 ________________________________________________________________________________
Date: Aug 29, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: A bunch of questions on shielding / grounding
> > >The issue with multiple ground paths is called ground loop. The voltage >of the ground wire at the ground terminal of a high current /high noise >device will not necessarily be 0 volts. This is so because when that >device is using a lot of power, the same amount of current is being >carried by both the power and ground leads. The current being carried >in the wires will raise the voltage at the ground connection of the >device, and lower it at the 12V connection. If a device uses 10A of >current, and its wired using the same size wire for both power and >ground, the voltage drop caused by the wire's resistance will be shared >by both leads. If you have 0.1ohm total resistance (to make the math >easy), then the total voltage drop is 1V, .5v on the ground and .5V on >the V+. > >No problem so far. However, if another device has its own power and >ground wires, but ALSO has a short ground path to the power hog, the >power hog will also start moving around the ground potential for the >more delicate/sensitive device. Its no big deal for light bulbs, and >electric motors, because they won't have their performance affected >significantly. But it could cause you headaches in your intercom (pun >intended). That changing ground potential would be just as bad as >wiggling the V+ lead by the same amount. No amount of filtering or >shielding will fix this. > >The question with where to ground an antenna's coax is a slightly >different one. The reason is that antennas are transmitting at (and >optimized for) a frequency where some motor or alternator induced noise >will have little effect. So, if you have a dipole with a ground plane, >the feed line's shield obviously needs to be connected to that ground >plane and (with the coax connector) to the radio chassis. If the ground >plane is shorted to the ground of a power hog (because you have a metal >plane for ex), there may not be much you can do about it, but it >probably won't cause you any problems. BTW, the ground plane doesn't >really need to be at the same ground as the battery (no need to run >a ground wire from the battery to the ground plane in a plastic >airplane), because the ground plane is just being used to 'fool' the >antenna into thinking it has a bottom half (for a dipole). From the >high frequency, EM standpoint, they look the same. > >Matt- Ground loops don't generally figure strongly in coax cable runs on metal airplanes . . and never on plastic airplanes. The most critical circuits are engine instrumentation and audio systems. With the single point ground system described in the 'Connection, ground loops are never an issue. The biggest potential problem with running wire bundles down opposite sides of the fuselage in a canard-pusher is the potential for having differential current flows down each side that creates a magnetic field in the cockpit that can have profound effects on the fluid compass. Had a builder several years back that ran a conduit down one side and a vacuum line down the other. He decided that the vacuum line could double as the fat wire conductor to the engine compartment. Circulating currents in these two pathways were so strong that his compass pointed perpetually to some value like 112 degrees and decidedly nose down. Compass worked find if he turned all electrics off. The advantage of putting all fore/aft pathways right together is that such magnetic fields are impossible both external to the conduit/wire bundle and highly attenuated with respect to coupling between various systems that share the bundle. This isn't really a ground loop issue but one of controlling magnetic radiation and inter-system magnetic coupling. Bob . . . ________________________________________________________________________________
Date: Aug 29, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: bunch of questions on shielding / grounding
> >The p-lead should be grounded to the mag (engine) only. The high >frequency (engergy) pulses that come up the center conductor of the >p-lead are coupled to its shield because of the length of the parallel >run of the conductors (coaxial). If you connect the p-lead shield to >some other ground at the panel, this coupled noise gets injected into >the ground at that point. This ground noise can be picked up by any >piece of equipment that is also grounded to the same place. There is >no possible benefit from grounding the p-lead to the panel. That's my >understanding, anyway. Pretty close. Again, we're looking for the attenuating effects of magnetic radiation by keeping currents on inside conductor equal to and opposite in direction as currents on outer conductor. If the wire "floats" at the panel end while the engine is running, the currents MUST be balanced. If you ground the shield at the panel end too, then there is almost assuredly a difference in current flows on the two conductors . . . I've had several p-lead noise problems get cured when the panel ground recommended by several DIY books was removed. A further benefit is that should an engine ground strap be unconnected, you don't want starter looking for a ground on your p-lead shields. Had two cases of wire-bundle burning happen on spam cans when mechanics I hired did just that . . tried to crank the engien through the p-lead shields. Bob . . . ________________________________________________________________________________
Date: Aug 29, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: RE: A bunch of questions on shielding / grounding
> >In your response you said that it would be better not to have multiple >paths. This seems counterintuitive. Would you please explain briefly why >you recommend not having wires on both sides of the fuselage (it isn't too >late for me to re-route the antenna coax on my Europa). > >Best regards, > >Rob Housman Coaxes are not part of the discussion. They can be routed separately but in a properly configured ground system, they can be easily routed with other wires as well. Folks who have experienced a "fix" to a noise problem by separating wire bundles are only mitigating the effects of poor architecture in the first place. Attention to detail on those little "racetracks" of electron races goes a long way to avoiding root cause of noise problems that won't require mitigation or cure. Bob . . . ________________________________________________________________________________
Date: Aug 29, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: A bunch of questions on shielding / grounding
> >In a message dated 8/28/02 3:30:46 PM Central Daylight Time, >bob.nuckolls(at)cox.net writes: > > > > EXCEPT p-leads from mags DO have very fast rise-time > > voltages on them and they WILL benefit from shielding. All of these > > wires can come down the same tube. > > > >Good Afternoon Bob, > >I know this has been plain to most, but I must have missed something >somewhere. > >Should the shielding on P-leads be grounded at both ends or just one? Which >end is best if it is to be only one? Just one . . . engine end as shown in wiring diagrams in the 'Connection. The shield is used to PROVIDE a ground for the magneto switch but should be connected to no other part of the system at the panel end. Bob . . . ________________________________________________________________________________
Date: Aug 29, 2002
From: Gary Liming <gary(at)liming.org>
Subject: Cover for firewall ground bus
I am using the firewall ground bus ("forest of tabs"), and was wondering if anyone has found something that makes a good cover for the tabs on the engine side? Thanks, Gary Liming ________________________________________________________________________________
Date: Aug 29, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re:
> > > > > >In the pure analog world, you'll to switch > > > > between 14 and 18 wires from the indicator to the two radios. > > > > This take a 18 pole, double throw switch . . . > > > > > >Could this be an application for those old computer printer switches? >They > > >switch 25 inputs to either of 25 outputs. > > >It might not work if it was for a printer, but old RS.232 seral >communication devices needed most of the 25 wires switched in an A-B switch >- except pin-7 which usually is common for RS-232 connections, and was >connected from the input to both of the outputs. Bear in mind that these >switches are designed for low power signal (+/- 12 V few mAmps). They will >not carry or break any significan amount of power. There are two varieties. Some use solid state, silicon switches that look like an array of chips on a pc board. The ol' hammer-n-tongs approach uses a two-position switch at up to 25 poles operated by a simple knob on the front panel. The later types have totally isolated, hard-switched channels that would be well suited to handling an array of analog signals between nav receivers and a remote mounted CDI/GS/OBS head. Bob . . . ________________________________________________________________________________
From: "Walter S. Fellows" <fellowsw(at)mondexkorea.com>
Subject: Cover for firewall ground bus
Date: Aug 30, 2002
I have a related question for covers for the contactors as well. In the early model Cessna 210s, all the connections and contactors in the engine compartment were uncovered. In the later models, they are all covered. When I asked a Cessna Pilot Association rep on this issue, he said he thought it had something to do with a "floating cowl" and moisture in the engine compartment. In sum, do you feel there are situations where the contactors and the other open electrical connections in the engine compartment and/or the cabin should be covered? -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Gary Liming Subject: AeroElectric-List: Cover for firewall ground bus I am using the firewall ground bus ("forest of tabs"), and was wondering if anyone has found something that makes a good cover for the tabs on the engine side? Thanks, Gary Liming = = = http://www.matronics.com/browselist/aeroelectric-list = ________________________________________________________________________________
Date: Aug 29, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: RE: Cover for firewall ground bus
> > >I have a related question for covers for the contactors as well. In the >early model Cessna 210s, all the connections and contactors in the >engine compartment were uncovered. In the later models, they are all >covered. When I asked a Cessna Pilot Association rep on this issue, he >said he thought it had something to do with a "floating cowl" and >moisture in the engine compartment. > >In sum, do you feel there are situations where the contactors and the >other open electrical connections in the engine compartment and/or the >cabin should be covered? It's been some time ago but I recall some of the gyrations Cessna went through over the floating cowl. Before some model year, trailing edges of cowls were screwed hard to a flange around the firewall. To reduce cabin noise, they attached later cowls on shock mounts that left a small but significant gap in the sheet metal at the trailing edge of the cowl and the firewall flange. When a shower comes along after a soak in the sun, cold water runs down the firewall. Some electro-whizzies bolted there would get a nice cold shower and rapidly reduced temperatures inside would drop internal air pressure. Even the tiniest hole would suck liquid water into the device. Now, water that entered as liquid was obliged to get out as a vapor through subsequent atmospheric breathing operations . . . needless to say, many devices got rusty inside pretty quick and failed. Cessna went through a period of trying to seal things up. We were asked to put RTV beads over all the joints of cover plates, etc on our products in an attempt to keep moisture out. Having had some experience with trying to keep electronics enclosures dry on tall towers I knew this effort was futile. I was president and chief hammer-n-tongs guy with the Air Capital Amateur Repeater Association. We had a 2 meter ham repeater on the 1200-foot platform of KTVH-TV near Hutchinson. I knew this effort was futile. The harder you try to seal, the more effectively you KEEP WATER TRAPPED INSIDE AFTER IT GETS SUCKED THROUGH THE HOLES YOU INVARIABLY MISSED. On the tower, we finally gave up and open the vents and added fans. What rain water did get inside might take the repeater off the air for awhile but it would quickly dry out and come back on. Many Cessnas can be found with hand applied uckum- yuckies of various kind over every conceivable water entry point on contactors, regulators and other firewall mounted goodies. Not sure it did a whole lot of good . . . but we got to raise the price of our regulator about $3 for the "extra" service. The only way to assure water tight enclosure was near-hermetic sealing. A subsequent design I did for Cessna offered a glass-filled nylon housing wherein leadwires came through thick, tight fitting, resilient grommets. The lid was o-ring sealed. We got shot out of the saddle on that program . . . they bought our competitor's product in a sheet metal housing doped with uckum-yuckie who came in about $7 less per item (out of $70) than our sealed version. I think they wound up mounting the new regulator off the firewall so it wouldn't get wet. An interesting feature of this experience was that the environmental concern for product longevity had nothing to do with the rigors of flight . . . summertime showers on a tied down airplane were our "Waterloo" . . . Bob . . . ________________________________________________________________________________
Date: Aug 29, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Batteries & other electrical stuff
Hi Bob, I purchased and read your book, "The AeroElectric Connection" and have some questions: Background: I'm building an RV-9A, I0-320 one mag/one electronic ignition (electronic on bottom), CS prop, all electric panel (no vacuum). I am taking your advice for the "mother of all electrical systems" and will install dual alternator/ dual battery system. * Which regulator do you recommend for the B&C 60 amp & the B&C 20 amp alternators? Is that the LR3C-14? One for each alternator, right? Right . . . but with dual alternators, consider the L-40 instead of an L-60. Save some weight and dollars. You'll never need all that snort unless you're running a coffee pot and microwave. * Do you have a favorite battery for this installation? Would two 17 AH batteries be appropriate or would you recommend saving some lb's with dual 12 AH's? A pair of 17's will be less expensive and available from MANY sources. The only 12 I know that's worth a toot is from B&C. A very good battery but more expensive too. * What brand/model battery would you recommend for price/performance? If it were my airplane, I'd go for a pair of 17's . . . buy 'em cheap and rotate out often. * Can you use a standard L/R/Both/Start keyed ignition switch for the Figure Z-27 schematic for the Mag/Electronic Ignition? No * What are your thoughts on those solar battery conditioners that plug into the auxiliary power outlet and provide a steady stream while the sun is shining? RG batteries don't need them. Here are my thoughts on the essential bus / main bus: Any thoughts, additions or changes (anything missing?) Position Lights AutoPilot Servos Strobe Professional systems AOA Pitot Heat Taxi/Landing Lights CO2 Detector Starter Switch Fuel Priming Pump Essential Buss Items: EFIS (primary flight instruments/ navigation/ engine instruments) Turn Coordinator (secondary flight instrument) Transponder Panel Lighting (with dimmer) Flaps Electric Trim & indicators (can these be separated? the indicator could go on the non-essential buss) amp/volt meter (one for each system) SL15-M Audio Panel1 GX-60 GPS/Com SL30 Nav/Com SL70 Transponder Hobbs Not the Hobbs. This works any time engine is running and oil pressure is up whether or not ANY electrical system stuff is ON. Your Schematic shows several items on the "Always On" buss. Won't some of these items (like the clock or a dome light that is left on) drain the battery if I don't fly for a while? What is the rational for keeping these hot all the time? I see the reason for the Electric Ignition to have constant power to it, but will it also draw amps while the engine is off? None of these items draw significant power if the switch is OFF. If you're worried about leaving anything ON, then there is equal risk of leaving the battery master ON too. The always hot bus lets you run a courtesy light without having any part of the airplane powered up. You could put an 0n-limit timer on it like they use on cars so you can walk away from the airplane in the dark and it will go off by itself. Always On Primary Buss: Engine Electronic Ignition Accessory Electric adapter (cigarette lighter type for a portable GPS or whatever) Primary Fuel Pump Clock/timer? Dome/Panel LED Lights? (I don't know how to put a dome light in an RV. Perhaps the best would be one of those LED lights that has a bulb that lasts forever and runs 20 hrs on a small battery.) That would work too . .. Always On Aux Battery Bus: Secondary Fuel Pump? What else? Hobbs meter. Thanks for your insight and help. My pleasure sir . . . How about joining us on the AeroElectric-List? You can sign up on Matronics.com Bob . . . |-------------------------------------------------------| | There is a great difference between knowing and | | understanding: you can know a lot about something and | | not really understand it. -C.F. Kettering- | |-------------------------------------------------------| ________________________________________________________________________________
From: "Walter S. Fellows" <fellowsw(at)mondexkorea.com>
Subject: RE: Cover for firewall ground bus
Date: Aug 30, 2002
Thanks for the insight.... You are an amazing resource. -----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: AeroElectric-List: RE: Cover for firewall ground bus > > >I have a related question for covers for the contactors as well. In the >early model Cessna 210s, all the connections and contactors in the >engine compartment were uncovered. In the later models, they are all >covered. When I asked a Cessna Pilot Association rep on this issue, he >said he thought it had something to do with a "floating cowl" and >moisture in the engine compartment. > >In sum, do you feel there are situations where the contactors and the >other open electrical connections in the engine compartment and/or the >cabin should be covered? It's been some time ago but I recall some of the gyrations Cessna went through over the floating cowl. Before some model year, trailing edges of cowls were screwed hard to a flange around the firewall. To reduce cabin noise, they attached later cowls on shock mounts that left a small but significant gap in the sheet metal at the trailing edge of the cowl and the firewall flange. When a shower comes along after a soak in the sun, cold water runs down the firewall. Some electro-whizzies bolted there would get a nice cold shower and rapidly reduced temperatures inside would drop internal air pressure. Even the tiniest hole would suck liquid water into the device. Now, water that entered as liquid was obliged to get out as a vapor through subsequent atmospheric breathing operations . . . needless to say, many devices got rusty inside pretty quick and failed. Cessna went through a period of trying to seal things up. We were asked to put RTV beads over all the joints of cover plates, etc on our products in an attempt to keep moisture out. Having had some experience with trying to keep electronics enclosures dry on tall towers I knew this effort was futile. I was president and chief hammer-n-tongs guy with the Air Capital Amateur Repeater Association. We had a 2 meter ham repeater on the 1200-foot platform of KTVH-TV near Hutchinson. I knew this effort was futile. The harder you try to seal, the more effectively you KEEP WATER TRAPPED INSIDE AFTER IT GETS SUCKED THROUGH THE HOLES YOU INVARIABLY MISSED. On the tower, we finally gave up and open the vents and added fans. What rain water did get inside might take the repeater off the air for awhile but it would quickly dry out and come back on. Many Cessnas can be found with hand applied uckum- yuckies of various kind over every conceivable water entry point on contactors, regulators and other firewall mounted goodies. Not sure it did a whole lot of good . . . but we got to raise the price of our regulator about $3 for the "extra" service. The only way to assure water tight enclosure was near-hermetic sealing. A subsequent design I did for Cessna offered a glass-filled nylon housing wherein leadwires came through thick, tight fitting, resilient grommets. The lid was o-ring sealed. We got shot out of the saddle on that program . . . they bought our competitor's product in a sheet metal housing doped with uckum-yuckie who came in about $7 less per item (out of $70) than our sealed version. I think they wound up mounting the new regulator off the firewall so it wouldn't get wet. An interesting feature of this experience was that the environmental concern for product longevity had nothing to do with the rigors of flight . . . summertime showers on a tied down airplane were our "Waterloo" . . . Bob . . . = = = http://www.matronics.com/browselist/aeroelectric-list = ________________________________________________________________________________
From: jerry(at)tr2.com
Subject: Re: RE: Cover for firewall ground bus
Date: Aug 29, 2002
Robert L. Nuckolls, III wrote: > > to a flange around the firewall. To reduce cabin noise, > they attached later cowls on shock mounts that left a > small but significant gap in the sheet metal at the > trailing edge of the cowl and the firewall flange. > > When a shower comes along after a soak in the sun, cold > water runs down the firewall. Some electro-whizzies bolted *** Yuck. That's just as bad as the fresh water distribution system on my Beech Sundowner. In their infinite wisdom, Beech located the fresh air vents on TOP of the cowl. You look down into each vent, there's a plastic funnel. Each funnel connects to a plastic manifold. The manifold has air hoses that go to various places in the airplane, and a small drain hose that goes straight down. When the plane was brand new, rainwater would pour through the cowl vents, down into the manifold, and drain out through the drains. With age, two things happened: * The drain tubes could get clogged. The manifolds would then fill to the brim with water. * The air ducting would age, get brittle, the reinforcing wire would abrade through the outer coat. Then a fine mixture of fresh water and air would be delivered to the aluminum innards. The plane's interior would lovingly hold that moisture up to the skeleton for long periods. Can you say "corrosion"? Ask me how I know :(. - Jerry Kaidor ( jerry(at)tr2.com ) ________________________________________________________________________________
From: "Vincent Welch" <welchvincent(at)hotmail.com>
Subject: Internal Regulator
Date: Aug 30, 2002
Bob, you have a drawing using a contactor to open the "B" lead when the Crowbar OV module is activated for alternators with internal regulators. In the past you have indicated that this is because there are "failure modes" that won't be eliminated with the Crowbar module alone. Just out of curiosity, what are these modes? What could cause an alternator to continue putting out voltage when the field is grounded through the crowbar? Vince Welch ________________________________________________________________________________
From: "Ned Thomas" <315(at)cox.net>
Subject: 100 deg 8x32 Torx screws
Date: Aug 30, 2002
I like the idea of the tox screws but have a question for those who bought them. I have been told that they are weaker than phillips head screws. Evidently more material is removed for the torx socket than for the phillips leaving a very thin structure. Is any tensile strength data available on the torx screws you bought so we can compare strengths? Thanks, Ned ________________________________________________________________________________
From: mprather(at)spro.net
Subject: Re: Internal Regulator
Date: Aug 30, 2002
Bob will probably also address this again, but the thing he mentioned before is that when you ground/open the control lead to the internal regulator, you aren't really grounding/opening the alternator field. I found this by searching for 'internal regulat' in the archive. Hopefully he will address the failure mode question as well - I am curious too. Matt- ----- Original Message ----- From: "Vincent Welch" <welchvincent(at)hotmail.com> Date: Friday, August 30, 2002 1:09 pm Subject: AeroElectric-List: Internal Regulator > > Bob, you have a drawing using a contactor to open the "B" lead when > the > Crowbar OV module is activated for alternators with internal > regulators. In > the past you have indicated that this is because there are "failure > modes" > that won't be eliminated with the Crowbar module alone. Just out > of > curiosity, what are these modes? What could cause an alternator to > continue > putting out voltage when the field is grounded through the crowbar? > > Vince Welch > > > _- > - The AeroElectric-List Email Forum - > _- > !! NEW !! > _- > List Related Information > _- > ======================================================================= > > > > > ________________________________________________________________________________
From: "Tom Barnes" <skytop(at)megsinet.net>
Subject: Re: Batteries & other electrical stuff
Date: Aug 31, 2002
Bob and others, Some other items you may consider: Wiring for a windshield defog fan, electronics cooling fan, and your annunciator lights and secondary comm. Tom Barnes -6 all electric (on a budget) ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: AeroElectric-List: Re: Batteries & other electrical stuff > > > Hi Bob, > > I purchased and read your book, "The AeroElectric Connection" and have some > questions: > > Background: > > I'm building an RV-9A, I0-320 one mag/one electronic ignition (electronic > on bottom), CS prop, all electric panel (no vacuum). I am taking your > advice for the "mother of all electrical systems" and will install dual > alternator/ dual battery system. > > * Which regulator do you recommend for the B&C 60 amp & the B&C 20 amp > alternators? Is that the LR3C-14? One for each alternator, right? > > Right . . . but with dual alternators, consider the L-40 instead > of an L-60. > Save some weight and dollars. You'll never need all that snort unless > you're running a coffee pot and microwave. > > * Do you have a favorite battery for this installation? Would two 17 > AH batteries be appropriate or would you recommend saving some lb's with > dual 12 AH's? > > A pair of 17's will be less expensive and available from MANY > sources. The only 12 I know that's worth a toot is from B&C. > A very good battery but more expensive too. > > * What brand/model battery would you recommend for price/performance? > > If it were my airplane, I'd go for a pair of 17's . . . buy > 'em cheap and rotate out often. > > * Can you use a standard L/R/Both/Start keyed ignition switch for the > Figure Z-27 schematic for the Mag/Electronic Ignition? > No > * What are your thoughts on those solar battery conditioners that plug > into the auxiliary power outlet and provide a steady stream while the sun > is shining? > > RG batteries don't need them. > > Here are my thoughts on the essential bus / main bus: Any thoughts, > additions or changes (anything missing?) > > Position Lights > > AutoPilot Servos > > Strobe > > Professional systems AOA > > Pitot Heat > > Taxi/Landing Lights > > CO2 Detector > > Starter Switch > > Fuel Priming Pump > > > Essential Buss Items: > > EFIS (primary flight instruments/ navigation/ engine instruments) > > Turn Coordinator (secondary flight instrument) > > Transponder > > Panel Lighting (with dimmer) > > Flaps > > Electric Trim & indicators (can these be separated? the indicator could go > on the non-essential buss) > > amp/volt meter (one for each system) > > SL15-M Audio Panel1 > > GX-60 GPS/Com > > SL30 Nav/Com > > SL70 Transponder > > Hobbs > > Not the Hobbs. This works any time engine is running and > oil pressure is up whether or not ANY electrical system > stuff is ON. > > > Your Schematic shows several items on the "Always On" buss. Won't some of > these items (like the clock or a dome light that is left on) drain the > battery if I don't fly for a while? What is the rational for keeping these > hot all the time? I see the reason for the Electric Ignition to have > constant power to it, but will it also draw amps while the engine is off? > > None of these items draw significant power if the switch is > OFF. If you're worried about leaving anything ON, then there > is equal risk of leaving the battery master ON too. The always > hot bus lets you run a courtesy light without having any part > of the airplane powered up. You could put an 0n-limit timer on > it like they use on cars so you can walk away from the airplane in > the dark and it will go off by itself. > > Always On Primary Buss: > > Engine Electronic Ignition > > Accessory Electric adapter (cigarette lighter type for a portable GPS or > whatever) > > Primary Fuel Pump > > Clock/timer? > > Dome/Panel LED Lights? (I don't know how to put a dome light in an > RV. Perhaps the best would be one of those LED lights that has a bulb that > lasts forever and runs 20 hrs on a small battery.) > > That would work too . .. > > Always On Aux Battery Bus: > > Secondary Fuel Pump? > > What else? > > Hobbs meter. > > Thanks for your insight and help. > > > My pleasure sir . . . How about joining us on the > AeroElectric-List? You can sign up on Matronics.com > > Bob . . . > > > |-------------------------------------------------------| > | There is a great difference between knowing and | > | understanding: you can know a lot about something and | > | not really understand it. -C.F. Kettering- | > |-------------------------------------------------------| > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Eric M. Jones" <emjones(at)charter.net>
Subject: Torx Screws
Date: Aug 31, 2002
I agree with Ned Thomas....Torx is NO miracle. a) Torx Bolts are sometimes useful, Torx screws much less so. b) Torx has "Torx" and "Torx-plus" drivers and they are different forms but hard to detect and NOT interchangeable. Which wrenches do YOU have in your toolbox? c) Torx screws are often weaker. I have had an entire 25,000 pc lot rejected because the heads popped off in assembly. Oops! d) The newest thing in recesses seem to be triangular (NOT tri-winged, similar to the Canadian screws but not as deep). So whatever you have--don't use worn drivers, replace damaged screws. Don't over tighten. And please let's keep this topic off Bob's Aero-ELECTRIC website. ________________________________________________________________________________
From: "Ronald A. Cox" <racox(at)ix.netcom.com>
Subject: Re: AeroElectric-List Digest: 17 Msgs - 08/28/02
Date: Aug 31, 2002
> RE: the 2-5 switch, so if I had a "one mag and one Jeff Rose EI" > arrangement, I could use this switch to ensure the EI is not engaged > while cranking, and put it on line as soon as the starter is disengaged. > Right? Like this: OFF - EI ON - (STARTER ON)? That would be a nice > arrangement. Any drawbacks? Why don't you want the EI engaged for start??? From what I hear, that's one of the main advantages: It starts like a car, and saves a LOT of wear and tear on the starter and battery. I'm counting on that, and will only have the Impulse Coupled magneto on the left because I can see a situation where I might want to start with that one, but it would be a VERY rare situation. Is there something I don't understand?? Ron ________________________________________________________________________________
From: "William Slaughter" <willslau(at)alumni.rice.edu>
Subject: Re: AeroElectric-List Digest: 17 Msgs - 08/28/02
Date: Aug 31, 2002
Improved starting is indeed one of the fundamental advantages of electronic ignitions. Rather than disable it during start-up, I'd fix whatever else in the electrical system that is impairing the function of the electronic ignition. William -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Ronald A. Cox Subject: AeroElectric-List: Re: AeroElectric-List Digest: 17 Msgs - 08/28/02 > RE: the 2-5 switch, so if I had a "one mag and one Jeff Rose EI" > arrangement, I could use this switch to ensure the EI is not engaged > while cranking, and put it on line as soon as the starter is disengaged. > Right? Like this: OFF - EI ON - (STARTER ON)? That would be a nice > arrangement. Any drawbacks? Why don't you want the EI engaged for start??? From what I hear, that's one of the main advantages: It starts like a car, and saves a LOT of wear and tear on the starter and battery. I'm counting on that, and will only have the Impulse Coupled magneto on the left because I can see a situation where I might want to start with that one, but it would be a VERY rare situation. Is there something I don't understand?? Ron http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
Date: Aug 31, 2002
From: "Boyd C. Braem" <bcbraem(at)comcast.net>
Subject: Re: AeroElectric-List Digest: 17 Msgs - 08/28/02
The way I understand this problem is as follows: In systems with a permanent magnet starter, when the starter is energized there is a very large in-rush current that can drop the bus voltage below the point where the control module for the EI system can accurately determine spark firing. This can result in backfiring that can damage the engine and the starter ring gear. As the engine starts to spin, the starter current begins to relax and the bus voltage rises. When the bus voltage is in the "normal" range for your EI system the control module can be activated and the module will provide the spark at the correct timing. This is not a universal problem but from what I hear it happens often enough that people with EI systems should be aware of the potential for problems. This can be further aggravated by a long battery cable run, weak battery, corroded/loose terminals, etc. If you have a VM-1000 engine monitor or other electronic monitor system, you'll get a clue if the VM-1000 "blinks" itself off during initial starter engagement. As always, I could be totally wrong. Boyd. press START--engine spinning--switch IGNITION ON William Slaughter wrote: > > Improved starting is indeed one of the fundamental advantages of electronic > ignitions. Rather than disable it during start-up, I'd fix whatever else in > the electrical system that is impairing the function of the electronic > ignition. > > William > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Ronald > A. Cox > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Re: AeroElectric-List Digest: 17 Msgs - > 08/28/02 > > > > > RE: the 2-5 switch, so if I had a "one mag and one Jeff Rose EI" > > arrangement, I could use this switch to ensure the EI is not engaged > > while cranking, and put it on line as soon as the starter is disengaged. > > Right? Like this: OFF - EI ON - (STARTER ON)? That would be a nice > > arrangement. Any drawbacks? > > Why don't you want the EI engaged for start??? > > >From what I hear, that's one of the main advantages: It starts like a car, > and saves a LOT of wear and tear on the starter and battery. > > I'm counting on that, and will only have the Impulse Coupled magneto on the > left because I can see a situation where I might want to start with that > one, but it would be a VERY rare situation. > > Is there something I don't understand?? > > Ron > > ________________________________________________________________________________
From: "Larry Bowen" <Larry(at)BowenAero.com>
Subject: Re: AeroElectric-List Digest: 17 Msgs - 08/28/02
Date: Aug 31, 2002
I thought the Rose EI needed to be off during starting -- I've since been told it doesn't. I've also heard from folks that are doing exactly as I described below, and swear it's working great. I believe the other brands of EI _do_ need to be off while cranking. I haven't flow with either -- only planning on buying the Rose EI soon, so I'm not the authority on any of this. - Larry Bowen Larry(at)BowenAero.com http://BowenAero.com > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of Ronald A. Cox > Sent: Saturday, August 31, 2002 2:32 PM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Re: AeroElectric-List Digest: 17 > Msgs - 08/28/02 > > > --> > > > RE: the 2-5 switch, so if I had a "one mag and one Jeff Rose EI" > > arrangement, I could use this switch to ensure the EI is > not engaged > > while cranking, and put it on line as soon as the starter is > > disengaged. Right? Like this: OFF - EI ON - (STARTER ON)? > That would > > be a nice arrangement. Any drawbacks? > > Why don't you want the EI engaged for start??? > > >From what I hear, that's one of the main advantages: It > starts like a > >car, > and saves a LOT of wear and tear on the starter and battery. > > I'm counting on that, and will only have the Impulse Coupled > magneto on the left because I can see a situation where I > might want to start with that one, but it would be a VERY > rare situation. > > Is there something I don't understand?? > > Ron > > > =========== > =========== > =========== > Search Engine: > http://www.matronics.com/search > =========== > > > ________________________________________________________________________________
From: "William Slaughter" <willslau(at)alumni.rice.edu>
Subject: Re: AeroElectric-List Digest: 17 Msgs - 08/28/02
Date: Aug 31, 2002
Take a look at www.lightspeedengineering.com for information on their units. William -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Larry Bowen Subject: RE: AeroElectric-List: Re: AeroElectric-List Digest: 17 Msgs - 08/28/02 I thought the Rose EI needed to be off during starting -- I've since been told it doesn't. I've also heard from folks that are doing exactly as I described below, and swear it's working great. I believe the other brands of EI _do_ need to be off while cranking. I haven't flow with either -- only planning on buying the Rose EI soon, so I'm not the authority on any of this. - Larry Bowen Larry(at)BowenAero.com http://BowenAero.com http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
From: "Stucklen" <wstucklen1(at)cox.net>
Subject: Electronic Ignitions
Date: Sep 01, 2002
Listers, I have an older Jeff Rose system, and did have a problem using it during engine start. (The solution was to allow the engine to start on the Mag.) I'm not sure about his newer systems that I am installing on the new plan I'm building. In that setup, I'm planning n 2 Jeff Rose EI systems. I'll also have two 17 AH batteries. During engine start, One battery will be used to run the starter, the other will power essential bus components. Fred Stucklen RV-6A N925RV 1996 Hrs of safe flying.... _______ From: "Larry Bowen" <Larry(at)BowenAero.com> Subject: RE: AeroElectric-List: Re: AeroElectric-List Digest: 17 Msgs - 08/28/02 I thought the Rose EI needed to be off during starting -- I've since been told it doesn't. I've also heard from folks that are doing exactly as I described below, and swear it's working great. I believe the other brands of EI _do_ need to be off while cranking. I haven't flow with either -- only planning on buying the Rose EI soon, so I'm not the authority on any of this. - Larry Bowen Larry(at)BowenAero.com http://BowenAero.com ________________________________________________________________________________
Date: Sep 01, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Electronic Ignitions
> >Listers, > > I have an older Jeff Rose system, and did have a problem using it >during engine start. (The solution was to allow the engine to start on >the Mag.) I'm not sure about his newer systems that I am installing on >the new plan I'm building. In that setup, I'm planning n 2 Jeff Rose EI >systems. I'll also have two 17 AH batteries. During engine start, One >battery will be used to run the starter, the other will power essential >bus components. How come? Bob . . . ________________________________________________________________________________
Date: Sep 01, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: RE: EI systems . . . cantankerous or crankers?
> >I thought the Rose EI needed to be off during starting -- I've since >been told it doesn't. I've also heard from folks that are doing exactly >as I described below, and swear it's working great. I believe the other >brands of EI _do_ need to be off while cranking. > >I haven't flown with either -- only planning on buying the Rose EI soon, >so I'm not the authority on any of this. > >- There is no better authority for the behavior of a product than the folks who designed and sell them. Given that modern EI systems are automotive derivatives wherein it's the ONLY ignition system and given further that the #1 advantage of EI is easier starting due to battery supplied power for hotter spark, I find it curious that any such system would have either a reputation -OR- a designed-in prohibition for using the EI system to get the engine running. Rather than debate hearsay, why not call the guys who sell these things, ask your questions and the publish both the questions and answers here on the list? It may be fun to sit on the steps of the library and hypothesize about what one will find inside based on the words of people who have never seen for themselves. However, I'll suggest that the real story is just on the other side of that unlocked door (or published phone number) with a welcome sign on it. Bob . . . ________________________________________________________________________________
Date: Sep 01, 2002
From: Matt Dralle <dralle(at)matronics.com>
Subject: Getting Bounced From Matronics Lists...
Dear Listers, I have two programs I run regularly to purge the various Matronics email lists of bad email addresses. I referred to these as my Email Weasels and there is a daily version that is run automatically every night at midnight and there is a and a monthly version that I run by hand at roughly 30-day intervals. The Daily Weasel grinds through the 8 to 10mb of bounced email that is generated each day looking for obvious things like "user unknown", "host unknown", and other things that usually mean the user's email address doesn't exist any longer. The Daily Weasel has been purging 5 to 10 email addresses each night. The Monthly Weasel gets more serious about the task and sends a single message to each list member with specially generated headers and content information. Any bounces or replies to these messages are considered errors and the email address is eligible for purging. This program is particularly useful for "weaseling out" email addresses that are actually being forwarded to by another email address that is subscribed to a List and otherwise would not be identifiable. The Monthly Weasel purges roughly 100 nonexistent email addresses each month when it is run. To check to see if your address has been removed by either of the Email Weasel programs, you can check the Weasel Status Web Page at the following URL: http://www.matronics.com/unsubscribed If you find your email address on the Weasel List, but are certain that everything is working fine now, simply go the Matronics Subscription page and resubscribe your address. No harm, no foul. The subscription URL is: http://www.matronics.com/subscribe That all having been said, I've noticed that the Daily Weasel may have been getting a little too aggressive in purging addresses recently and a number of people have written asking if and why they'd been dropped from the List. A couple of months ago I rewrote the Daily Weasel program to include a wider variety of errors and more aggressively purge. One of the new purge criteria that I added seems to occur a fair amount of the time (Connection Deferred) even though the address is really okay. As of today, I've removed the Connection Deferred criteria from the Daily Weasel Rule set and this should decrease the number of "false positives" and unnecessary unsubscribed. Again, if you get unsubscribed by either of the Email Weasel utilities, simply go to the subscription page and resubscribe: http://www.matronics.com/subscribe Best regards, Matt Dralle Matronics Email List Admin. Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551 925-606-1001 V | 925-606-6281 F | dralle(at)matronics.com Email http://www.matronics.com/ WWW | Featuring Products For Aircraft They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety. Benjamin Franklin Historical Review of Pennsylvania, 1759 ________________________________________________________________________________
Date: Sep 01, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Torx Screws
> >I agree with Ned Thomas....Torx is NO miracle. > >a) Torx Bolts are sometimes useful, Torx screws much less so. > >b) Torx has "Torx" and "Torx-plus" drivers and they are different forms >but hard to detect and NOT interchangeable. Which wrenches do YOU have >in your toolbox? > >c) Torx screws are often weaker. I have had an entire 25,000 pc lot >rejected because the heads popped off in assembly. Oops! > >d) The newest thing in recesses seem to be triangular (NOT tri-winged, >similar to the Canadian screws but not as deep). > >So whatever you have--don't use worn drivers, replace damaged screws. >Don't over tighten. > >And please let's keep this topic off Bob's Aero-ELECTRIC website. It's not my list server, it's yours. I also don't see any problem with spreading the truth and light about any product or technology that will improve our craftsmanship . . . screws and bolts are used to hold electro-whizzies together . . . they're also used to hold said whizzies down in the airplane. I've seen "bad" lots of all kinds of fasteners. RAC got a whole order (like thousands of pounds) of bad rivets once . . . didn't get caught until way too many had found their way onto the production line. Very messy business to find and purge . . . Our light of salvation for OBAM aircraft is that we need and want to understand a lot more about our project than those fresh graduates on the assembly line. The only way we'll understand is by critical review of information to sort the good stuff from bad stuff. More than anything else, I would hope that's what this list server is about. Bob . . . |-------------------------------------------------------| | There is a great difference between knowing and | | understanding: you can know a lot about something and | | not really understand it. -C.F. Kettering- | |-------------------------------------------------------| ________________________________________________________________________________
Date: Sep 01, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Electronic Ignitions
> >Listers, > > I have an older Jeff Rose system, and did have a problem using it >during engine start. (The solution was to allow the engine to start on >the Mag.) I'm not sure about his newer systems that I am installing on >the new plan I'm building. In that setup, I'm planning n 2 Jeff Rose EI >systems. I'll also have two 17 AH batteries. During engine start, One >battery will be used to run the starter, the other will power essential >bus components. > >Fred Stucklen >RV-6A N925RV >1996 Hrs of safe flying.... Did you talk to Jeff about this? ________________________________________________________________________________
Date: Sep 01, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Internal Regulator
> >Bob will probably also address this again, but the thing he mentioned >before is that when you ground/open the control lead to the internal >regulator, you aren't really grounding/opening the alternator field. I >found this by searching for 'internal regulat' in the archive. Hopefully >he will address the failure mode question as well - I am curious too. > >Matt- Built in regulators come in dozens of flavors both from original manufacturers and aftermarket sources. Without having specific design information on the regulator in question, I cannot make a considered judgement about its performance or failure modes. Of perhaps a dozen schematics I have seen, one side the the field is hard connected to the alternator b-lead terminal. The other side gets pulled to ground through a single power transistor. There were several failure modes, including failure of the transistor itself that would produced a runaway alternator that could not be controlled from the outside. It IS possible to design a built-in regulator where actual field power comes through the control lead, but I've never seen one. It IS possible to build in adequate OV protection too . . . I've seen only one schematic that claimed to have protection. It was a poor-man's crowbar system using a zener and fuse in the field's + power lead . . . not unlike ov protection in many Grummans of some years back. It's the variability in products that drives my recommendations. Even if your alternator had ALL the necessary goodies and features to be an aircraft alternator when it left the factory, how do you know for sure that the regulator is not an aftermarket replacement with less than ideal characteristics? Hence my recommendations that unless you KNOW for a fact how your internal regulator's fault modes behave, it is best to ASSUME the worst and add the external protection. Bob . . . ________________________________________________________________________________
From: "Werner Schneider" <WernerSchneider(at)compuserve.com>
Subject: Where to position parts and main wire size
Date: Sep 01, 2002
Hello Bob, today I have a mechanical question in the environment of electricity. Due to the fact, that my Glastar will be a bit on the noseheavy side, I have to mount the battery way back in the aeroplane. I've learned, that I need to put the battery contactor also there. I will run a negative pole (~12ft) in the fuselage (glasfiber) to the firewall, connect it to my ground bus there (2 AWG?). On the other side a grounding strap will be connected to the engine. A 8AWG wire will run in parallel to the main Bus fuse sockets. What size should the battery bus wire have? Should I add there a fuse link? I will mount my starter contactor on the frontside of the firewall connect the starter via a 2AWG to it. A 4AWG wire will run through the firewall directly to the battery contactor way back in the fuselage. From the alternator a 6 AWG wire runs via a shunt (mounted on the front of the firewall?) to the starter contactor. Now, where do I mount the LR3C regulator? I think it makes sense to mount it on the back of the firewall, as only one wire has to go trough the firewall? For all the other wires I have planned to run all my sensor wires (including the 20AWG Field wire) through one firewall pass through. All the wires from the Lasar ignition and the 20AWG for the starter contactor through another separat hole and the 4AWG to the battery contactor through a third hole. Does this make sense? Many thanks for your help Werner (GlaStar #5794 closer to going electrics). ________________________________________________________________________________
From: "Britt Jensen" <dbjensen(at)thebigmouse.com>
Subject: Ferrite Cores...
Date: Sep 01, 2002
Is there any benefit to putting ferrite cores around the cable bundle near the connectors on back of any given radio/GPS? I understand these suppress EMI/RFI quite effectively...If so, do you put it around data, analog and pwr/ground lines, or just data and analog signal lines? Should I use separate cores for power connections versus data/analog? Thanks! Britt '67 Cherokee Six N3950W ________________________________________________________________________________
From: "Stucklen" <wstucklen1(at)cox.net>
Subject: Electronic Ignitions
Date: Sep 01, 2002
Bob, Yes, I did talk to Jeff about this. Turns out it's the starter pulling the bus voltage below 9 volts when it is initially engaged. That resets the E.I. and occasionally causes a misfire. My solution has been just to always start on the impulse mag, and enable the E.I. after the engine starts. Fred Stucklen RV-6A N925RV 1996 Hrs of safe flying.... Subject: Re: Electronic Ignitions From: Robert L. Nuckolls, III (bob.nuckolls(at)cox.net) Date: Sun Sep 01 - 12:35 PM > >Listers, > > I have an older Jeff Rose system, and did have a problem using it >during engine start. (The solution was to allow the engine to start on >the Mag.) I'm not sure about his newer systems that I am installing on >the new plan I'm building. In that setup, I'm planning n 2 Jeff Rose EI >systems. I'll also have two 17 AH batteries. During engine start, One >battery will be used to run the starter, the other will power essential >bus components. > >Fred Stucklen >RV-6A N925RV >1996 Hrs of safe flying.... Did you talk to Jeff about this? ________________________________________________________________________________
Date: Sep 02, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Electronic Ignitions
> > Bob, > > Yes, I did talk to Jeff about this. Turns out it's the starter >pulling the bus voltage below 9 volts when it is initially engaged. That >resets the E.I. and occasionally causes a misfire. My solution has been >just to always start on the impulse mag, and enable the E.I. after the >engine starts. > > Fred Stucklen > RV-6A N925RV > 1996 Hrs of safe flying.... Wonder if there's a way we can keep the supply voltage from dropping below 9v. When we test an RG battery, we load it to 8.5 volts at the terminals and get outputs in the 400-700A range. It seems that we should be able to keep the EI system at 9v or better during a 200-250A crank. Have you ever checked your battery terminal voltage while cranking? Bob . . . ________________________________________________________________________________
From: "Fergus Kyle" <VE3LVO(at)rac.ca>
Subject: Tinned wire vs. not
Date: Sep 02, 2002
"AeroElectric-List message posted by: "Richard V. Reynolds" The Ancor brand wire/cable sold by BOAT/US and West Marine is probably better than welding cable because it is "tinned". Salt air in an aircraft is not as much of a problem as in a boats, but all my non-tinned wire in my boat has a nice green patinia at the connectors. Ancor brand wire is good. Richard Reynolds" Richard, I raised this concern (Tinned vs. not) on another net. Mine compeer asked me if I was building a 747. He noted that none of his house wiring was deteriorated, and checking mine found that the 1941 wire was pristine. Unless one is near brine, I believe the simple welding wire is superior for this purpose. Cheers, Ferg, Europa A064 ________________________________________________________________________________
Date: Sep 02, 2002
From: John Rourke <john@allied-computer.com>
Subject: Re: Electronic Ignitions
Fred: Is your EI getting power from the main bus, or the battery bus? If it's getting it from the main bus, then it will see the same voltage drop (due to starter current) through the battery, battery cable and master contactor as the starter sees - that will contribute to the problem... if it's on the battery bus, it will only see the voltage drop (due to starter current) through the battery itself... and your starter will be seeing even less! Incidentally, have you checked the voltage at the starter itself? Bob: I was just double-checking your circuit diagrams in Appendix Z (dated 11/01), and noticed a discrepancy... On page Z-4, your comment about digram Z-27 (listed as "Magneto and 1 Eelctronic Ignition"), refers to both as magnetos, where the second pole of the EI power switch, according to the diagram Z-27, "provides a means for inteconnecting the switches such that the starter is disabled while the right (non-impulse coupled) magneto is ON.", according to the text on Z-4. Is it a typo in the text, or on the diagram? As I see it, the diagram is appropriate for TWO magnetos, but the labeling (and heading) states that it is 1 magneto and 1 EI, and the wiring shown prevents the EI from working during starter operation, which goes against both your comments here and the recommendations of the maunfacturer (to use the EI for starting). Incidentally, given that the EI is also supposed to fire at TDC, and given a situation where the EI supply voltage is sufficient, is it OK to use *both* EI and impulse-coupled mag for starting? Thanks, -John Robert L. Nuckolls, III wrote: > > >> >> Bob, >> >> Yes, I did talk to Jeff about this. Turns out it's the starter >>pulling the bus voltage below 9 volts when it is initially engaged. That >>resets the E.I. and occasionally causes a misfire. My solution has been >>just to always start on the impulse mag, and enable the E.I. after the >>engine starts. >> >> Fred Stucklen >> RV-6A N925RV >> 1996 Hrs of safe flying.... >> > > Wonder if there's a way we can keep the > supply voltage from dropping below 9v. > When we test an RG battery, we load it > to 8.5 volts at the terminals and > get outputs in the 400-700A range. > It seems that we should be able to keep > the EI system at 9v or better during a > 200-250A crank. > > Have you ever checked your battery terminal > voltage while cranking? > > Bob . . . > ________________________________________________________________________________
Date: Sep 02, 2002
From: Falcon <rsdec1(at)isp01.net>
Subject: firewall packing
Does anyone out there have any experience with any of the ceramic cloth materials where they would be used as packing to stuff firewall grommets to provide fire resistance. Some of the products available are available from McMaster-Carr i.e. Ceramic fiber strips p/n 87575K87 and/or ceramic sleeve packing (p/n 87675K83). There are also silica rope packing that appear to provide extreme temperature resistance. Thanks, RD ________________________________________________________________________________
From: BAKEROCB(at)aol.com
Date: Sep 02, 2002
Subject: acceptable topic?
AeroElectric-List message previously posted by: "Robert L. Nuckolls, III" Eric M. Jones wrote "....skip.......And please let's keep this topic off Bob's Aero-ELECTRIC website." And then Bob wrote: It's not my list server, it's yours. I also don't see any problem with spreading the truth and light about any product or technology that will improve our craftsmanship . . . screws and bolts are used to hold electro-whizzies together . . . they're also used to hold said whizzies down in the airplane. I've seen "bad" lots of all kinds of fasteners. RAC got a whole order (like thousands of pounds) of bad rivets once . . . didn't get caught until way too many had found their way onto the production line. Very messy business to find and purge . . . Our light of salvation for OBAM aircraft is that we need and want to understand a lot more about our project than those fresh graduates on the assembly line. The only way we'll understand is by critical review of information to sort the good stuff from bad stuff. More than anything else, I would hope that's what this list server is about. Bob . . . 9/2/2002 Hello Bob, Many thanks for speaking out -- I deeply appreciate both your philosophy and your willingness to defend it. 'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - ?/?/? ________________________________________________________________________________
From: "Cuper Richardson" <cuper(at)computer.org>
Subject: DC Power Master circuit protection
Date: Sep 02, 2002
Bob, In the "Connection, Rev 10", page 11-20, last paragraph you state "note that there is no circuit breaker associated with the control circuit of a battery master contactor. This is because there are no failure modes that would burn the wire. ..." What if the contactor solenoid coil shorted such that the coil had little or no resistance. Wouldn't you then have the battery positive switched directly to ground through the battery master switch? It seems to me you would rather have a fuse than use the 22 AWG wire as a fusable link. Am I missing something here? My practical experience is a little out of date, but I've seen several contactor coils short over the years. Thanks ________________________________________________________________________________
Date: Sep 03, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: DC Power Master circuit protection
> > >Bob, > >In the "Connection, Rev 10", page 11-20, last paragraph you state >"note that there is no circuit breaker associated with the control >circuit of a battery master contactor. This is because there are no >failure modes that would burn the wire. ..." > >What if the contactor solenoid coil shorted such that the coil had >little or no resistance. Wouldn't you then have the battery positive >switched directly to ground through the battery master switch? It >seems to me you would rather have a fuse than use the 22 AWG wire as a >fusable link. Am I missing something here? > >My practical experience is a little out of date, but I've seen several >contactor coils short over the years. > >Thanks While one might be concerned about a coil "shorting' it's pretty rare. I don't think I've ever seen one present as a shorted coil. Further, wire used to wind contactor solenoids is much finer stuff than the wire used to hook it up. Even if the coil DID short, the wire would separate interally to the contactor. Of course, these articles may have begun their demise with a shorted coil that soon translated to an open coil. Didn't do a teardown to find out. In any case, the "unprotected" pull to ground technique for contactors has been common practice for over 50 years on several hundred thousand airplanes. If there were much potential for hazard, I think we would have heard about it. Bob . . . ________________________________________________________________________________
From: "Gary Casey" <glcasey(at)adelphia.net>
Subject: 9-volt systems
Date: Sep 03, 2002
<<> Yes, I did talk to Jeff about this. Turns out it's the starter >pulling the bus voltage below 9 volts when it is initially engaged. That >resets the E.I. and occasionally causes a misfire. My solution has been >just to always start on the impulse mag, and enable the E.I. after the >engine starts. > > Fred Stucklen > RV-6A N925RV > 1996 Hrs of safe flying.... Wonder if there's a way we can keep the supply voltage from dropping below 9v. When we test an RG battery, we load it to 8.5 volts at the terminals and get outputs in the 400-700A range. It seems that we should be able to keep the EI system at 9v or better during a 200-250A crank. Have you ever checked your battery terminal voltage while cranking? Bob . . .>> I'm surprised that the ignition would "reset" when the voltage dropped below 9. Keeping a 12-volt system above 9 during cranking is a difficult chore. The initial automotive systems we built required 9 volts and we had trouble even with the big batteries in cars. All automotive systems have long since been based on 5-volt microprocessors and there have been "low drop-out" regulators developed that will effectively run the systems down to less than 6 volts. Gary Casey ________________________________________________________________________________
From: "Jim Pack" <jpack(at)igs3.com>
Subject: Switches on Battery Buss
Date: Sep 03, 2002
Bob, On the "always on", Battery Buss & Auxiliary Battery Buss (Dual Alt/Dual Bat system), is it recommended to have on/off switches for every item? Are there any items that should not have a switch, but should always be on? Could/Should these items all be on a single switch? Jim ________________________________________________________________________________
From: "Ken Simmons" <ken(at)truckstop.com>
Subject: 9-volt systems
Date: Sep 03, 2002
Here's an idea that I used to solve a similar problem in an automotive application. It may not work in this case because the EI probably draws too much current, but it's something to think about. I placed a diode in series between the supply and the device. A relatively large electrolytic cap was placed across the supply in between the diode and the device. When cranking, the cap stored enough energy to keep the supply to the device above the threshold. Obviously, this is heavily dependent on current draw of the device and the cranking time. Ken > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Gary > Casey > Sent: Tuesday, September 03, 2002 7:46 AM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: 9-volt systems > > > > > <<> Yes, I did talk to Jeff about this. Turns out it's the starter > >pulling the bus voltage below 9 volts when it is initially engaged. That > >resets the E.I. and occasionally causes a misfire. My solution has been > >just to always start on the impulse mag, and enable the E.I. after the > >engine starts. > > > > Fred Stucklen > > RV-6A N925RV > > 1996 Hrs of safe flying.... > > Wonder if there's a way we can keep the > supply voltage from dropping below 9v. > When we test an RG battery, we load it > to 8.5 volts at the terminals and > get outputs in the 400-700A range. > It seems that we should be able to keep > the EI system at 9v or better during a > 200-250A crank. > > Have you ever checked your battery terminal > voltage while cranking? > > Bob . . .>> > > I'm surprised that the ignition would "reset" when the voltage > dropped below > 9. Keeping a 12-volt system above 9 during cranking is a difficult chore. > The initial automotive systems we built required 9 volts and we > had trouble > even with the big batteries in cars. All automotive systems have > long since > been based on 5-volt microprocessors and there have been "low drop-out" > regulators developed that will effectively run the systems down > to less than > 6 volts. > > Gary Casey > > ________________________________________________________________________________
From: jerry(at)tr2.com
Subject: Re: 9-volt systems
Date: Sep 03, 2002
Ken Simmons wrote: > > Here's an idea that I used to solve a similar problem in an automotive > application. It may not work in this case because the EI probably draws too > much current, but it's something to think about. > > I placed a diode in series between the supply and the device. A relatively > large electrolytic cap > *** I hear there are some mighty big caps being made today. New process, caps big enough to crank a *starter motor*. It was discussed on this list some months ago. - Jerry ________________________________________________________________________________
Date: Sep 03, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Tinned wire vs. not
> > >"AeroElectric-List message posted by: "Richard V. Reynolds" > >The Ancor brand wire/cable sold by BOAT/US and West Marine is probably >better than welding cable because it is "tinned". Salt air in an aircraft is >not as much of a problem as in a boats, but all my non-tinned wire in my >boat has a nice green patinia at the connectors. Ancor brand wire is good. >Richard Reynolds" > >Richard, > I raised this concern (Tinned vs. not) on another net. Mine compeer asked >me if I was building a 747. He noted that none of his house wiring was >deteriorated, and checking mine found that >the 1941 wire was pristine. Unless one is near brine, I believe the simple >welding wire is superior for this purpose. >Cheers, Ferg, Europa A064 "Superior" is a relative term. If we have achieved gas-tight joints everywhere the wire gets attached to system components, then ELECTRICAL performance of the wire is assured. Insulation and finish focus on ENVIRONMENTAL performance with respect to abrasion resistance, flexibility, corrosion resistance, longevity etc. Lots of fine strands is better than fewer for flexibility and resistance to vibration damage. Beyond that, it's a choice of how important it is to you do deal with potential maintenance issues. Bob . . . ________________________________________________________________________________
Date: Sep 03, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Ferrite Cores...
> > >Is there any benefit to putting ferrite cores around the cable bundle >near the connectors on back of any given radio/GPS? I understand these >suppress >EMI/RFI quite effectively...If so, do you put it around data, analog and >pwr/ground lines, or just data and analog signal lines? Should I use >separate cores for power connections versus data/analog? Filters of ALL type should be used only after the need for them has been demonstrated. The vast majority of systems install with no need for additional efforts to avoid or reduce noise. Bob . . . ________________________________________________________________________________
Date: Sep 03, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Where to position parts and main wire size
> > >Hello Bob, > >today I have a mechanical question in the environment of electricity. > >Due to the fact, that my Glastar will be a bit on the noseheavy side, I have >to mount the battery way back in the aeroplane. I've learned, that I need to >put the battery contactor also there. I will run a negative pole (~12ft) in >the fuselage (glasfiber) to the firewall, connect it to my ground bus there >(2 AWG?). Yes . . . > On the other side a grounding strap will be connected to the >engine. Good . . . >A 8AWG wire will run in parallel to the main Bus fuse sockets. Don't understand the question driven by this data point . .. > What size should the battery bus wire have? Battery buses are typically lightly loaded . . . but in any case, the wire should be rated for continuous load anticipated for the battery bus. > Should I add there a fuse link? No, this wire should be short . . . the battery bus needs to mount right next to the battery contactor. >I will mount my starter contactor on the frontside of the firewall connect >the starter via a 2AWG to it. Okay . . . > A 4AWG wire will run through the firewall >directly to the battery contactor way back in the fuselage. This should be 2AWG too . . . > From the >alternator a 6 AWG wire runs via a shunt (mounted on the front of the firewall?) to the starter contactor. Fine . . . >Now, where do I mount the LR3C regulator? I think it makes sense to mount it >on the back of the firewall, as only one wire has to go trough the firewall? Fully optional. If single firewall penetration is important to you, by all means mount on the cockpit side of firewall. >For all the other wires I have planned to run all my sensor wires (including >the 20AWG Field wire) through one firewall pass through. All the wires from >the Lasar ignition and the 20AWG for the starter contactor through another >separat hole and the 4AWG to the battery contactor through a third hole. > >Does this make sense? Everything can run through the same penetration. How are you planning to provide fire-proof protection for the penetration? Bob . . . |-------------------------------------------------------| | There is a great difference between knowing and | | understanding: you can know a lot about something and | | not really understand it. -C.F. Kettering- | |-------------------------------------------------------| ________________________________________________________________________________
Date: Sep 03, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: "Brownout" during cranking . . .
> >The way I understand this problem is as follows: > >In systems with a permanent magnet starter, when the starter is energized >there is a very >large in-rush current that can drop the bus voltage below the point where >the control >module for the EI system can accurately determine spark firing. This can >result in >backfiring that can damage the engine and the starter ring gear. As the >engine starts to >spin, the starter current begins to relax and the bus voltage rises. When >the bus voltage >is in the "normal" range for your EI system the control module can be >activated and the >module will provide the spark at the correct timing. > >This is not a universal problem but from what I hear it happens often >enough that people >with EI systems should be aware of the potential for problems. This can >be further >aggravated by a long battery cable run, weak battery, corroded/loose >terminals, etc. If >you have a VM-1000 engine monitor or other electronic monitor system, >you'll get a clue if >the VM-1000 "blinks" itself off during initial starter engagement. > >As always, I could be totally wrong. This is an excellent example of why one needs to be CRITICAL of every piece of information that is not accompanied with an explanation of the physics. Readers of dozens of list-servers are belabored with the notion that EI systems SHOULD NOT be used for engine cranking because they barf when the voltage drops too low. This statement doesn't tell us enough. The quesions to ask are: Does engine cranking normally pull the battery voltage down so far that the EI system (or any other system) is starved for operating power? Is the battery incapable of delivering necessary voltage at engine cranking loads? I'll bet that every builder that's had problems with the EI system during cranking has one or more of the following conditions operating in his airplane: Battery is undersized, two old, improperly maintained and/or poor choice of technology (flooded vs. RG). Wiring in aircraft is too small. Architecture of the system does not take advantage of a battery bus that gets to tap energy from the battery BEFORE you throw away energy in the voltage drop of conductors that carry (+) side of cranking circuit. This is a system integration problem, not a design deficiency on the part of EI suppliers. Unfortunately, most folks won't pick up on this and will resign themselves to keeping one mag on their airplane so that they can get it started in spite of poor electrical system design. Bob . . . ________________________________________________________________________________
Date: Sep 03, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: 100 deg 8x32 Torx screws
> >I like the idea of the tox screws but have a question for those who >bought them. I have been told that they are weaker than phillips head >screws. Evidently more material is removed for the torx socket than for >the phillips leaving a very thin structure. > >Is any tensile strength data available on the torx screws you bought so >we can compare strengths? Tensile strength of any threaded fastener is most often established by the cross section of material of the thread's minor diameter. It's hard to imagine any treatment by design of the faster head that would make the head attachment a tensile strength factor. Of course, there are always manufacturing errors (a-la RAC's rivet problem I mentioned) but these are thankfully very rare events. Bob . . . ________________________________________________________________________________
Date: Sep 03, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: RE: 9-volt systems
> >Here's an idea that I used to solve a similar problem in an automotive >application. It may not work in this case because the EI probably draws too >much current, but it's something to think about. > >I placed a diode in series between the supply and the device. A relatively >large electrolytic cap was placed across the supply in between the diode and >the device. When cranking, the cap stored enough energy to keep the supply >to the device above the threshold. Obviously, this is heavily dependent on >current draw of the device and the cranking time. I've done this too on a number of products . . . in this case, the weight of a suitable capacitor could be more than the weight of properly sized wire. Bob . . . ________________________________________________________________________________
Date: Sep 03, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Switches on Battery Buss
> >Bob, > >On the "always on", Battery Buss & Auxiliary Battery Buss (Dual Alt/Dual >Bat system), is it recommended to have on/off switches for every item? Aside from items listed below, what devices would you be willing to drive from a single switch. If these same devices were powered from the main bus, would you STILL want to use a single switch. I don't see any difference in the switch decisions based on which bus drives the system. >Are there any items that should not have a switch, but should always be >on? Sure. Clocks, hobbs meter (controlled by its own oil pressure switch) memory supply for radios . . . ________________________________________________________________________________
From: HCRV6(at)aol.com
Date: Sep 03, 2002
Subject: Re: 9-volt systems
In a message dated 9/3/02 7:37:39 AM Pacific Daylight Time, ken(at)truckstop.com writes: Here's an idea that I used to solve a similar problem in an automotive application. It may not work in this case because the EI probably draws too much current, but it's something to think about. I placed a diode in series between the supply and the device. A relatively large electrolytic cap was placed across the supply in between the diode and the device. When cranking, the cap stored enough energy to keep the supply to the device above the threshold. Obviously, this is heavily dependent on current draw of the device and the cranking time. Ken >> Just a wild thought but could one use a small Nicad or probably better, an NMIH battery pack instead of a capacitor in this arrangement? Harry Crosby Pleasanton, California RV-6, electrical stuff ________________________________________________________________________________
Date: Sep 03, 2002
Subject: Re: "Brownout" during cranking . . .
From: Denis Walsh <deniswalsh(at)earthlink.net>
I have been running my O-360 with Sky Tec starter, and Jeff Rose system on right side, Slick with impulse on left side, for a lot of starts (approx 1000 hours). I subscribe to Nuckolls' comments entirely. I would only add that there are a couple other ways to get kick back ( that I know of), and probably more. Recently I installed a separate starter switch and have tried quite a few starts with EI only , both systems, and with mag only. Can't tell any difference. With my set up, it is interesting to note that when the battery is so weak that the cranking voltage sags below 9, then getting enough out of the starter for a complete revolution is usually impossible. This version of the "kick back" is a relatively harmless failure to get past top dead center on the first cylinder. I am personally therefore a little puzzled as to why it would be a problem if the EI "reset" at less than 9 volts. Perhaps with a smaller engine displacement and/or higher compression??? > From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> > Reply-To: aeroelectric-list(at)matronics.com > Date: Tue, 03 Sep 2002 11:48:35 -0500 > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Re: "Brownout" during cranking . . . > > > > This is an excellent example of why one needs to be > CRITICAL of every piece of information that is not > accompanied with an explanation of the physics. > > Readers of dozens of list-servers are belabored with > the notion that EI systems SHOULD NOT be used for engine > cranking because they barf when the voltage drops too > low. This statement doesn't tell us enough. The quesions > to ask are: > > Does engine cranking normally pull the battery voltage > down so far that the EI system (or any other system) > is starved for operating power? Is the battery incapable > of delivering necessary voltage at engine cranking loads? > > I'll bet that every builder that's had problems with > the EI system during cranking has one or more of the > following conditions operating in his airplane: > > Battery is undersized, two old, improperly maintained > and/or poor choice of technology (flooded vs. RG). > > Wiring in aircraft is too small. > > Architecture of the system does not take advantage > of a battery bus that gets to tap energy from the > battery BEFORE you throw away energy in the voltage > drop of conductors that carry (+) side of cranking > circuit. > > This is a system integration problem, not > a design deficiency on the part of EI suppliers. > Unfortunately, most folks won't pick up on this and > will resign themselves to keeping one mag on their > airplane so that they can get it started in spite > of poor electrical system design. > > Bob . . . > > > > > > ________________________________________________________________________________
From: "Jim Pack" <jpack(at)igs3.com>
Subject: Panel Switch Layout
Date: Sep 03, 2002
Does anyone have picturs or drawings of the switch configurations used on a dual amp/dual battery panel? - Jim ________________________________________________________________________________
From: "Stucklen" <wstucklen1(at)cox.net>
Subject: "Brownout" during cranking . . .
Date: Sep 03, 2002
Bob Here's the specifics on my RV-6A : a.. One mag, one E.I system (purcahsed in 1992, so maybe the newer units are better???)... b.. Sky_Tec 149-12HT Starter, rebuilt in the last 20 hours.. c.. #2 wire from battery positive terminal, to Master Solemoid (electrical system Common power point), to Starter Solenoid, to the starter. d.. # 2 wire from battery neg terminal to firewall bronze bolt (eletrical system common ground), to engine case. e.. Concord RG-35 (25 A Hr) new 12 months ago. f.. While cranking, the bus voltage to the E.I. system falls below 9 volts. In my aircraft, if the E.I. system was enabled, this occasionally caused the E.I. system to cause the engine to backfire. I therefore will not enable the E.I system during cranking as it could cause engine damage. If the eletrical design is capable of causing a starting sequence backfire under the worst case equipment status scenario, it's a bad electrical system design (in my opionion) and another approach should be investigated. While preventive maintenence measures always be taken (like changing the battery every two years..), the failure to do so should not jeopardize other equipment (it should only cause the engine not to start)... Some other starting solution, like starting on the mag only, or cranking the engine starter on one 17 AH battery, and powering the ignitions systems on another, should be explored. I do agree with your statements below: We all should be cognizant of the potential issues in the electrical system design. Unfortuneatly, not every builder is an electrical engineer capable of designing every aspect of the electrical system in the aircraft they are building. Your efforts to educate the experimental community, especially with working examples of how the designs should be implemented, are to be commended.... Fred Stucklen RV-6A N925RV 1996 Hours of safe flying.... Subject: Re: "Brownout" during cranking . . . From: Robert L. Nuckolls, III (bob.nuckolls(at)cox.net) Date: Tue Sep 03 - 9:49 AM This is an excellent example of why one needs to be CRITICAL of every piece of information that is not accompanied with an explanation of the physics. Readers of dozens of list-servers are belabored with the notion that EI systems SHOULD NOT be used for engine cranking because they barf when the voltage drops too low. This statement doesn't tell us enough. The quesions to ask are: Does engine cranking normally pull the battery voltage down so far that the EI system (or any other system) is starved for operating power? Is the battery incapable of delivering necessary voltage at engine cranking loads? I'll bet that every builder that's had problems with the EI system during cranking has one or more of the following conditions operating in his airplane: Battery is undersized, two old, improperly maintained and/or poor choice of technology (flooded vs. RG). Wiring in aircraft is too small. Architecture of the system does not take advantage of a battery bus that gets to tap energy from the battery BEFORE you throw away energy in the voltage drop of conductors that carry (+) side of cranking circuit. This is a system integration problem, not a design deficiency on the part of EI suppliers. Unfortunately, most folks won't pick up on this and will resign themselves to keeping one mag on their airplane so that they can get it started in spite of poor electrical system design. Bob . . . ________________________________________________________________________________
Date: Sep 03, 2002
From: "Boyd C. Braem" <bcbraem(at)comcast.net>
Subject: Re: Electronic Ignitions
For the Light Speed ignition system the low voltage threshold is 8 volts (per their manual). This seems safely low, but with a Sky-Tech permanent magnet starter I bust this limit on every start. However, once the engine is "spinning" (with no ignition source ON) the bus voltage comes back up and I can engage the EI and have a successful start. It does not have to started on the mag. If have have the EI ON during initial energizing of the starter I invariably get a misfire--so I don't do dat--but had to learn the hard way, since the early manuals for the Light Speed don't really address this issue. I got a nice trouble-shooting chart from the tech people at Sky-Tech. My Concorde 25XC battery is at the aft most fuselage bulkhead of an RV-6 with a loooong cable run. Boyd. "Robert L. Nuckolls, III" wrote: > > > > Bob, > > > Yes, I did talk to Jeff about this. Turns out it's the starter > >pulling the bus voltage below 9 volts when it is initially engaged. That > >resets the E.I. and occasionally causes a misfire. My solution has been > >just to always start on the impulse mag, and enable the E.I. after the > >engine starts. > > > Fred Stucklen > > RV-6A N925RV > > 1996 Hrs of safe flying.... > > Wonder if there's a way we can keep the > supply voltage from dropping below 9v. > When we test an RG battery, we load it > to 8.5 volts at the terminals and > get outputs in the 400-700A range. > It seems that we should be able to keep > the EI system at 9v or better during a > 200-250A crank. > > Have you ever checked your battery terminal > voltage while cranking? > > Bob . . . > ________________________________________________________________________________
From: "Stucklen" <wstucklen1(at)cox.net>
Subject: Brownout" during cranking . . .
Date: Sep 03, 2002
As Bob pointed out, we still need all the facts. My Jeff rose E.I. system was purchased in 1992. I now have two newer (improved???) units for the new RV-6A I'm building. Are they the same as the older units? Do they have the same type of low voltage reset issues that I've experienced in the older unit? Since these are not "Certified" inits(that means their design is frozen in time...), I have no way of knowing what design improvements have been performed since 1992. I don't have answers for these questions electrical system design issues yet. Only through experimentation will I be able to resolve this issue. (I might even try putting a new E.I. on the old plane and see what happens with an old battery during start...) Fred Stucklen RV-6A N925RV 1996 Hrs of safe flying Subject: Re: Re: "Brownout" during cranking . . . From: Denis Walsh (deniswalsh(at)earthlink.net) Date: Tue Sep 03 - 11:30 AM I have been running my O-360 with Sky Tec starter, and Jeff Rose system on right side, Slick with impulse on left side, for a lot of starts (approx 1000 hours). I subscribe to Nuckolls' comments entirely. I would only add that there are a couple other ways to get kick back ( that I know of), and probably more. Recently I installed a separate starter switch and have tried quite a few starts with EI only , both systems, and with mag only. Can't tell any difference. With my set up, it is interesting to note that when the battery is so weak that the cranking voltage sags below 9, then getting enough out of the starter for a complete revolution is usually impossible. This version of the "kick back" is a relatively harmless failure to get past top dead center on the first cylinder. I am personally therefore a little puzzled as to why it would be a problem if the EI "reset" at less than 9 volts. Perhaps with a smaller engine displacement and/or higher compression??? ________________________________________________________________________________
From: David Chalmers <David(at)ChalmersFamily.com>
Subject: Brownout" during cranking . . .
Date: Sep 03, 2002
For another data point I have a Lightspeed Plasma II ignition on my 0-200 (8.5 compression), Mag on the right. The Mag is disabled during start. I have a long run to the battery (12 ft) and the #4 cables are marginal when cranking. When I ran the Lightspeed off the regular power bus I found that it would often not start until the instant I released the starter switch. The Lightspeed installation insructions tell you to run separate cables to the battery for the ignition power. I made this change and the engine has started perfectly on the electronic ignition since then. BTW I have an additional circuit that disables the magneto for 2 seconds after the starter button is released. I have heard that the mag will sometimes cause kickback as the prop comes to a stop just after the starter is diengaged. I trust the Lightspeed to not cause kickback but ask me again in a few hundred hours. I did notice that the LSI requires a minimum speed before it will generate a spark. If you just turn the prop slowly you don't get any spark - I assume that helps. David Chalmers -----Original Message----- From: Stucklen [mailto:wstucklen1(at)cox.net] Subject: AeroElectric-List: Brownout" during cranking . . . As Bob pointed out, we still need all the facts. My Jeff rose E.I. system was purchased in 1992. I now have two newer (improved???) units for the new RV-6A I'm building. Are they the same as the older units? Do they have the same type of low voltage reset issues that I've experienced in the older unit? Since these are not "Certified" inits(that means their design is frozen in time...), I have no way of knowing what design improvements have been performed since 1992. I don't have answers for these questions electrical system design issues yet. Only through experimentation will I be able to resolve this issue. (I might even try putting a new E.I. on the old plane and see what happens with an old battery during start...) Fred Stucklen RV-6A N925RV 1996 Hrs of safe flying Subject: Re: Re: "Brownout" during cranking . . . From: Denis Walsh (deniswalsh(at)earthlink.net) Date: Tue Sep 03 - 11:30 AM I have been running my O-360 with Sky Tec starter, and Jeff Rose system on right side, Slick with impulse on left side, for a lot of starts (approx 1000 hours). I subscribe to Nuckolls' comments entirely. I would only add that there are a couple other ways to get kick back ( that I know of), and probably more. Recently I installed a separate starter switch and have tried quite a few starts with EI only , both systems, and with mag only. Can't tell any difference. With my set up, it is interesting to note that when the battery is so weak that the cranking voltage sags below 9, then getting enough out of the starter for a complete revolution is usually impossible. This version of the "kick back" is a relatively harmless failure to get past top dead center on the first cylinder. I am personally therefore a little puzzled as to why it would be a problem if the EI "reset" at less than 9 volts. Perhaps with a smaller engine displacement and/or higher compression??? http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
From: mprather(at)spro.net
Subject: Re: Brownout" during cranking . . .
Date: Sep 03, 2002
It seems like it would be practical to design the ignition system so that it doesn't spark at all if the bus voltage drops too much. That should be the failure behavior of the system. I agree with the idea that low voltage to the EI during starting shouldn't lead to engine damage. If its true that these EI systems can mis-time their output due to low voltage, I think we as consumers should lean on the EI makers to fix this problem, or not buy their products. For those that are stuck with the problem, it might be possible to retrofit something to the EI installation to eliminate the possibility of damage. It seems that a (possibly crude) solution would be to design a circuit similar to Bob's low voltage warning light driver that instead disables the EI. The EI could be disabled in 3 ways that I can think of, all by the inclusion of some kind of relay (solid state might be most reliabl). The first, which would probably involve the lowest switching load, would be to interrupt the signals generated by the ignition triggers. It seems like most of the ignitions use low voltage hall effect sensors. This method would work as long as the low voltage dropout fault didn't cause the EI to fire without respect to receiving input. Another place would be to interrupt the signals driving the coils. This would involve much higher switching loads - both current and voltage. It must also be considered that interrupting the current going through the coils will cause the plugs to fire - regardless of timing. Probably not good. Maybe the safest method would be to have the low voltage dropout circuit to disable the power input to the EI until the bus voltage returns to normal. It seems like the ignitions are drawing about 1-5A, which shouldn't be impossible to control with a relay. Its possible the manufacturers of the EI's can't provide data about the way in which their system malfunctions in response to voltage drop. If this is the case, and someone is persistent about using that system, then gathering some test data on a mockup is probably in order. If it turns out that timing instabililty is really the issue, then that's a shame. The EI systems should be able to absolutely kick-butt during startup. I'll be surprised if this is a problem with LSE's current products. Klaus advertises the input voltage spec as ranging from 4V to 35V. See: http://www.lightspeedengineering.com/Products/IgnitionSpecs.htm If the starting voltage drops to 4V during cranking, engine damage seems unlikely. Any thoughts? Matt Prather. ----- Original Message ----- From: "Stucklen" <wstucklen1(at)cox.net> Date: Tuesday, September 3, 2002 1:31 pm Subject: AeroElectric-List: Brownout" during cranking . . . > > As Bob pointed out, we still need all the facts. My Jeff rose E.I. > system was purchased in 1992. I now have two newer (improved???) units > for the new RV-6A I'm building. Are they the same as the older > units? Do > they have the same type of low voltage reset issues that I've > experienced in the older unit? Since these are not "Certified" > inits(that means their design is frozen in time...), I have no way of > knowing what design improvements have been performed since 1992. > I don't have answers for these questions electrical system design > issues yet. Only through experimentation will I be able to resolve > thisissue. (I might even try putting a new E.I. on the old plane > and see > what happens with an old battery during start...) > > Fred Stucklen > RV-6A N925RV > 1996 Hrs of safe flying > > Subject: Re: Re: "Brownout" during cranking . . . > From: Denis Walsh (deniswalsh(at)earthlink.net) > Date: Tue Sep 03 - 11:30 AM > > > > I have been running my O-360 with Sky Tec starter, and Jeff Rose > systemon > right side, Slick with impulse on left side, for a lot of starts > (approx1000 hours). > > I subscribe to Nuckolls' comments entirely. I would only add that > thereare ________________________________________________________________________________
From: "Werner Schneider" <WernerSchneider(at)compuserve.com>
Subject: Re: Where to position parts and main wire size
Date: Sep 03, 2002
Hello Bob, many thanks, helps a lot to get a confirmation. For the few open things see below. I did cut out the already answered questions. > >A 8AWG wire will run in parallel to the main Bus fuse sockets. > > Don't understand the question driven by this data point . .. Sorry, parallel to the 12 ft ground wire (2AWG) I will run a 8 AWG fire for the positive pol to the fuse socket plate for the main bus (size could be calculated through expected load, but with some reserve for future expansion), right? > > > What size should the battery bus wire have? > > > Battery buses are typically lightly loaded . . . but in > any case, the wire should be rated for continuous load > anticipated for the battery bus. > > > > Should I add there a fuse link? > > No, this wire should be short . . . the battery bus > needs to mount right next to the battery contactor. Ok, so I mount it in the back ,a few inches from the battery contactor away and run the few wires for this items from the panel back to the fuse socket. > >Now, where do I mount the LR3C regulator? I think it makes sense to mount it > >on the back of the firewall, as only one wire has to go trough the firewall? > > Fully optional. If single firewall penetration > is important to you, by all means mount on the > cockpit side of firewall. > > > >For all the other wires I have planned to run all my sensor wires (including > >the 20AWG Field wire) through one firewall pass through. All the wires from > >the Lasar ignition and the 20AWG for the starter contactor through another > >separat hole and the 4AWG to the battery contactor through a third hole. > > > >Does this make sense? > > Everything can run through the same penetration. How are you > planning to provide fire-proof protection for the penetration? So far I've planned to use a rubber gromet in the Firewall, protected by a RTV paste and on top a stainless steel shield. Single was not planned so far but I'm listening to advice, I have five engine controlls each passing through a separate drilling, one big pass through for cabin heat, the positive cable (2AWG) to the starter contactor, one pass through on the left hand side with all the cabels from the ignition and the LR-3 another one slightly right of the center with all the sensor wiring. The idea is, to keep the hole of the passtrough as small as possible. Thanks for sharing all your experience through your book AND your active participation in this list! Werner ________________________________________________________________________________
Date: Sep 03, 2002
From: RSwanson <rswan19(at)comcast.net>
Subject: Re: Brownout" during cranking . . .
I know nothing about aircraft electronic ignition, but on auto electronic ignition every time power is applied or turned off the coil will fire. I would assume this is what's happening to cause the misfire. Roger ________________________________________________________________________________
Date: Sep 03, 2002
From: John Rourke <john@allied-computer.com>
Subject: Re: Brownout" during cranking . . .
With all due respect, I just don't see the problem. If the EI is installed on a battery bus, anything less than 9 volts at the battery tells me that something is wrong. Either the battery is drained, worn, undersized, or the wrong type; or the connection has excessive resistance, or the starter is pulling too many amps. In any of the above cases, it's time to fix the problem not design in a work-around which itself can cause additional failure modes. And if the EI is on the main bus, it's in the wrong place, in my opinion. The main bus will always see a portion of the voltage drop caused by the starter's enormous current flow during starting (through the battery cable, master contactor and at least three connections). If you put it on the battery bus (or a dedicated line back to the battery, fused of course), the only voltage drop (due to starting current) that will affect it is that of the battery itself - and that should be only a fraction of the total voltage drop that the starter (or main bus) sees. In most cases, the EI units we use come from automotive applications. Shouldn't we hook them up the way they were originally used, with a separate connection to the battery, independent of the starter? And, for that matter, the ground to the EI should be independent as well. And as for the failure mode, if the EI is on the battery directly, any voltage low enough to make the EI misbehave is going to be so much more lower at the starter, that the starter won't even be able to spin it fast enough to light off the ignition anyway - ergo, no problem. -John mprather(at)spro.net wrote: > > It seems like it would be practical to design the ignition system so > that it doesn't spark at all if the bus voltage drops too much. That > should be the failure behavior of the system. I agree with the idea > that low voltage to the EI during starting shouldn't lead to engine > damage. If its true that these EI systems can mis-time their > output due to low voltage, I think we as consumers should lean on the > EI makers to fix this problem, or not buy their products. For those > that are stuck with the problem, it might be possible to retrofit > something to the EI installation to eliminate the possibility of damage. > > It seems that a (possibly crude) solution would be to design a circuit > similar to Bob's low voltage warning light driver that instead disables > the EI. The EI could be disabled in 3 ways that I can think of, all by > the inclusion of some kind of relay (solid state might be most reliabl). > The first, which would probably involve the lowest switching load, would > be to interrupt the signals generated by the ignition triggers. It > seems like most of the ignitions use low voltage hall effect sensors. > This method would work as long as the low voltage dropout fault didn't > cause the EI to fire without respect to receiving input. > > Another place would be to interrupt the signals driving the coils. This > would involve much higher switching loads - both current and voltage. > It must also be considered that interrupting the current going through > the coils will cause the plugs to fire - regardless of timing. Probably > not good. > > Maybe the safest method would be to have the low voltage dropout circuit > to disable the power input to the EI until the bus voltage returns to > normal. It seems like the ignitions are drawing about 1-5A, which > shouldn't be impossible to control with a relay. > > Its possible the manufacturers of the EI's can't provide data about the > way in which their system malfunctions in response to voltage drop. If > this is the case, and someone is persistent about using that system, > then gathering some test data on a mockup is probably in order. > > If it turns out that timing instabililty is really the issue, then > that's a shame. The EI systems should be able to absolutely kick-butt > during startup. I'll be surprised if this is a problem with LSE's > current products. Klaus advertises the input voltage spec as ranging > from 4V to 35V. See: > > http://www.lightspeedengineering.com/Products/IgnitionSpecs.htm > > If the starting voltage drops to 4V during cranking, engine damage seems > unlikely. > > Any thoughts? > > Matt Prather. > > ----- Original Message ----- > From: "Stucklen" <wstucklen1(at)cox.net> > Date: Tuesday, September 3, 2002 1:31 pm > Subject: AeroElectric-List: Brownout" during cranking . . . > > >> >>As Bob pointed out, we still need all the facts. My Jeff rose E.I. >>system was purchased in 1992. I now have two newer (improved???) units >>for the new RV-6A I'm building. Are they the same as the older >>units? Do >>they have the same type of low voltage reset issues that I've >>experienced in the older unit? Since these are not "Certified" >>inits(that means their design is frozen in time...), I have no way of >>knowing what design improvements have been performed since 1992. >> I don't have answers for these questions electrical system design >>issues yet. Only through experimentation will I be able to resolve >>thisissue. (I might even try putting a new E.I. on the old plane >>and see >>what happens with an old battery during start...) >> >>Fred Stucklen >>RV-6A N925RV >>1996 Hrs of safe flying >> >> Subject: Re: Re: "Brownout" during cranking . . . >> From: Denis Walsh (deniswalsh(at)earthlink.net) >> Date: Tue Sep 03 - 11:30 AM >> >> >> >>I have been running my O-360 with Sky Tec starter, and Jeff Rose >>systemon >>right side, Slick with impulse on left side, for a lot of starts >>(approx1000 hours). >> >>I subscribe to Nuckolls' comments entirely. I would only add that >>thereare >> > > > > > > > > > ________________________________________________________________________________
From: mprather(at)spro.net
Subject: Re: Brownout" during cranking . . .
Date: Sep 03, 2002
Agreed. That's why I said it the way I did... "If its true that these EI systems can mis-time their output due to low voltage" ... "If it turns out that timing instabililty is really the issue, then that's a shame." I didn't make it clear. If there is an installation problem (which I suspect there probably is), you can't blame the misbehavior on the EI. I still think the EI's should have accurate timing if they are going to fire at all, regardless of the input voltage. I think its pretty clunky not to... I don't have experience with another scenario in my head.... If a battery has a dead cell (I know, RG batteries are rugged), but the other cells are good, will the battery be able to crank the engine (albeit slowly)? Matt- ----- Original Message ----- From: John Rourke <john@allied-computer.com> Date: Tuesday, September 3, 2002 5:55 pm Subject: Re: AeroElectric-List: Brownout" during cranking . . . > computer.com> > With all due respect, I just don't see the problem. > > If the EI is installed on a battery bus, anything less than 9 volts > at > the battery tells me that something is wrong. Either the battery is > drained, worn, undersized, or the wrong type; or the connection has > excessive resistance, or the starter is pulling too many amps. In > any of > the above cases, it's time to fix the problem not design in a > work-around which itself can cause additional failure modes. > > And if the EI is on the main bus, it's in the wrong place, in my > opinion. The main bus will always see a portion of the voltage drop > caused by the starter's enormous current flow during starting > (through > the battery cable, master contactor and at least three > connections). If > you put it on the battery bus (or a dedicated line back to the > battery, > fused of course), the only voltage drop (due to starting current) > that > will affect it is that of the battery itself - and that should be > only a > fraction of the total voltage drop that the starter (or main bus) > sees. > In most cases, the EI units we use come from automotive > applications. > Shouldn't we hook them up the way they were originally used, with a > separate connection to the battery, independent of the starter? > And, for > that matter, the ground to the EI should be independent as well. > > And as for the failure mode, if the EI is on the battery directly, > any > voltage low enough to make the EI misbehave is going to be so much > more > lower at the starter, that the starter won't even be able to spin > it > fast enough to light off the ignition anyway - ergo, no problem. > > -John > > > mprather(at)spro.net wrote: > > > > > It seems like it would be practical to design the ignition system so > > that it doesn't spark at all if the bus voltage drops too much. ________________________________________________________________________________
Date: Sep 03, 2002
Subject: Re: "Brownout" during cranking . . .
From: Denis Walsh <deniswalsh(at)earthlink.net>
Being a curious soul I decided to check out this alleged phenomena. I refer to brown out, back fire (kick back), and EI crap out. I have consequently recently installed a separate starter switch so I could start with either my `1998 vintage Jeff Rose system or on the magneto, a 1995 model Slick with impulse. Previous to this I almost always started using both ignition systems. Sometimes I would start with only the magneto. The incidence of kick back was the same in either both or Mag. In all cases it was either due to low voltage (sick battery or poor connections), or to hot engine start, where pre ignition would occur. Since I have the new starter switch, I cannot tell any difference in the way it starts whether in mag, EI, or both. My current (pun intended) battery is an odyssey, model 625, which is 9.5 months old and has about 150 hours or about 250 starts on it. Occurrences of kick back have been greatly reduced since introduction of this battery. Further, since I removed my firewall starter contactor, the cranking energy has increased and the kick back occurrence has gone away except for the hot engine variety. > From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> > Reply-To: aeroelectric-list(at)matronics.com > Date: Tue, 03 Sep 2002 11:48:35 -0500 > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Re: "Brownout" during cranking . . . > > > >> >> >> The way I understand this problem is as follows: >> >> In systems with a permanent magnet starter, when the starter is energized >> there is a very >> large in-rush current that can drop the bus voltage below the point where >> the control >> module for the EI system can accurately determine spark firing. This can >> result in >> backfiring that can damage the engine and the starter ring gear. As the >> engine starts to >> spin, the starter current begins to relax and the bus voltage rises. When >> the bus voltage >> is in the "normal" range for your EI system the control module can be >> activated and the >> module will provide the spark at the correct timing. >> >> This is not a universal problem but from what I hear it happens often >> enough that people >> with EI systems should be aware of the potential for problems. This can >> be further >> aggravated by a long battery cable run, weak battery, corroded/loose >> terminals, etc. If >> you have a VM-1000 engine monitor or other electronic monitor system, >> you'll get a clue if >> the VM-1000 "blinks" itself off during initial starter engagement. >> >> As always, I could be totally wrong. > > This is an excellent example of why one needs to be > CRITICAL of every piece of information that is not > accompanied with an explanation of the physics. > > Readers of dozens of list-servers are belabored with > the notion that EI systems SHOULD NOT be used for engine > cranking because they barf when the voltage drops too > low. This statement doesn't tell us enough. The quesions > to ask are: > > Does engine cranking normally pull the battery voltage > down so far that the EI system (or any other system) > is starved for operating power? Is the battery incapable > of delivering necessary voltage at engine cranking loads? > > I'll bet that every builder that's had problems with > the EI system during cranking has one or more of the > following conditions operating in his airplane: > > Battery is undersized, two old, improperly maintained > and/or poor choice of technology (flooded vs. RG). > > Wiring in aircraft is too small. > > Architecture of the system does not take advantage > of a battery bus that gets to tap energy from the > battery BEFORE you throw away energy in the voltage > drop of conductors that carry (+) side of cranking > circuit. > > This is a system integration problem, not > a design deficiency on the part of EI suppliers. > Unfortunately, most folks won't pick up on this and > will resign themselves to keeping one mag on their > airplane so that they can get it started in spite > of poor electrical system design. > > Bob . . . > > > > > > ________________________________________________________________________________
From: "Brian & Debi Shannon" <wings(at)theshannons.net>
Subject: Keyed ignition and Z-27
Date: Sep 03, 2002
Hi Bob, In a previous post you said that the keyed ignition would not work with Z-27, dual alt, dual batt, one mag, one elect. ignition. I was under the impression Lightspeed made an electronic ignition that let you use the keyed ignition swith...Why wouldn't this work with Z-27? Thanks for the help! -- Brian S. * Can you use a standard L/R/Both/Start keyed ignition switch for the Figure Z-27 schematic for the Mag/Electronic Ignition? No --- Checked by AVG anti-virus system (http://www.grisoft.com). ________________________________________________________________________________
Date: Sep 03, 2002
From: Bill Irvine <wgirvine(at)yahoo.com>
Subject: Re: Electronic Ignitions
> Turns out it's the starter pulling the bus voltage > below 9 volts when it is initially engaged. That > resets the E.I. and occasionally causes a misfire. If your starter is pulling your bus voltage below 9 volts, then your battery is too small (or not fully charged.) Bill http://finance.yahoo.com ________________________________________________________________________________
Date: Sep 03, 2002
From: Ed Holyoke <bicyclop(at)pacbell.net>
Subject: 100 deg 8x32 Torx screws
Ned, I don't know what the tensile strength is, but I did e-mail Vans Aircraft to ask them if they were OK with using them for mounting the fuel tanks. They replied that there is no strength issue. I had microfasteners send me some sample screws which I put through hell. I ran them in and out of nutplates with a cordless drill. After a couple of uses, I can see some damage to the head where the torx bit hits the splines. I don't know if this is from using a cheapo torx bit or not. The screws were very easy to remove even after several times in and out. Much better than Phillips. I think that I would probably replace them if I ever did remove them just to be safe. I'm guessing that most planes never have the tanks removed. If you needed to though, I think the torx screws would be easier to get out. Good luck, Ed Holyoke RV-6 qb >I like the idea of the tox screws but have a question for those who bought them. I have been told that they are weaker than phillips head screws. Evidently more material is removed for the torx socket than for the phillips leaving a very thin structure. Is any tensile strength data available on the torx screws you bought so we can compare strengths? Thanks, Ned ________________________________________________________________________________
Date: Sep 04, 2002
From: Graham Singleton <grasingleton(at)avnet.co.uk>
Subject: Re: AeroElectric-List Digest: 28 Msgs - 09/03/02
I know nothing about aircraft electronic ignition, but on auto electronic ignition every time power is applied or turned off the coil will fire. I would assume this is what's happening to cause the misfire. Roger You may have hit on the problem. Low battery performance sometimes causes the master or starter solenoid to trip in and out, which will switch the EI off, hence a spark. Most likely in the wrong place. My 2 cent guess Graham ________________________________________________________________________________
Date: Sep 04, 2002
From: Graham Singleton <grasingleton(at)avnet.co.uk>
Subject: Re: AeroElectric-List Digest: 28 Msgs - 09/03/02
> >I like the idea of the tox screws but have a question for those who > >bought them. I have been told that they are weaker than phillips head > >screws. Evidently more material is removed for the torx socket than for > >the phillips leaving a very thin structure. > > > >Is any tensile strength data available on the torx screws you bought so > >we can compare strengths? > > Tensile strength of any threaded fastener is most often > established by the cross section of material of the > thread's minor diameter. It's hard to imagine any > treatment by design of the faster head that would > make the head attachment a tensile strength factor. However. In the case of AN525-3s used on Long EZ nose legs, it's relatively easy to pull the heads off by overtightening them (to stop the wheel falling off). Reason is that the recess in the head extends into or too close to the shank of the screw. I once did it myself and it became obvious, the cross section of the shank was reduced by about half. If you think it might be an issue a close look at design is indicated. On EZs we now use AN3 bolts in that application. I was lucky, my nosewheel didn't go through the prop {{;-) Graham ________________________________________________________________________________
Date: Sep 04, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Keyed ignition and Z-27
> > >Hi Bob, > > In a previous post you said that the keyed ignition would not work with >Z-27, dual alt, dual batt, one mag, one elect. ignition. I was under the >impression Lightspeed made an electronic ignition that let you use the keyed >ignition swith...Why wouldn't this work with Z-27? Thanks for the help! > >-- Brian S. There are ways to add a control lead to an electronic ignition to make it compatible with magneto control switches. If Lightspeed has done so -AND- you've got a favorable disposition toward the keyswitch then by all means . . . If your EI system is controlled by switching power on and off via the ignition control switch, then the keyswitch will not work. Bob . . . ________________________________________________________________________________
Date: Sep 04, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Switch Terminal Numbering
Hi Bob, Maybe I'm loosing it or something but awhile back when I was doing my wiring I had a problem with your diagram on page 11-16. I should have sent you a message then but did not. Now I'm thinking about it again and that's why I'm writing. I latterly spent hours trying to wire some double pole switches using the diagram: 6 3 5 2 4 1 Finally I started doing continuity checks and found the diagram (looking at the switch from the back) should be: 3 6 2 5 1 4 I feel the problem was that the depiction on 11-16 was looking through the switch from the front view. However it is clearly shown as a rear view. Is the drawing wrong? Help!!!!!! No, there are TWO versions of the 2-10 switch, one made by Microswitch which used to dominate our diagrams before we found an inexpensive source and added them to our catalog. The two products swap columns as viewed from the back. I'll be adding a note of clarification in a future revision. The "answer" is to determine which style you have either by brand name or by ohmmeter and wire accordingly. Bob . . . |-------------------------------------------------------| | There is a great difference between knowing and | | understanding: you can know a lot about something and | | not really understand it. -C.F. Kettering- | |-------------------------------------------------------| ________________________________________________________________________________
Date: Sep 04, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Magnetos
Hi Bob, Drawing Z8 for my RV8. I'm wondering why there is no impulse coupler shown on the left magneto in the drawing? Also, do you have any articles you have written about magnetos? I just hung my engine and will be connecting all the wiring from aircraft to engine soon. How do you recommend wiring the left magneto. Thanks! Steve Glasgow ... ! ... \............O............/ You can run either style of magneto with an electronic ignition on the other side be it the left or right-hand hole on the engine. I recommend that builders get their money's worth by running one mag with EI until that mag craps. Then put the other mag back on and run it until it dies. Only then do you need to purchase the second EI. You don't get much if any discount on an engine purchase by having it shipped less mags. Further, 90% of the performance improvement by adding EI is realized on the first installation. You might consider updating your book by downloading the revised chapters from my website. It sounds like you have an Rev 9 or earlier book. I will invite you to join us on the AeroElectric List to continue this and similar discussions. It's useful to share the information with as many folks as possible. You can join at . . . http://www.matronics.com/subscribe/ Thanks! Bob . . . |-------------------------------------------------------| | There is a great difference between knowing and | | understanding: you can know a lot about something and | | not really understand it. -C.F. Kettering- | |-------------------------------------------------------| ________________________________________________________________________________
Date: Sep 04, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Brownout" during cranking . . .
><john@allied-computer.com> > >With all due respect, I just don't see the problem. > >If the EI is installed on a battery bus, anything less than 9 volts at >the battery tells me that something is wrong. Either the battery is >drained, worn, undersized, or the wrong type; or the connection has >excessive resistance, or the starter is pulling too many amps. In any of >the above cases, it's time to fix the problem not design in a >work-around which itself can cause additional failure modes. > >And if the EI is on the main bus, it's in the wrong place, in my >opinion. The main bus will always see a portion of the voltage drop >caused by the starter's enormous current flow during starting (through >the battery cable, master contactor and at least three connections). If >you put it on the battery bus (or a dedicated line back to the battery, >fused of course), the only voltage drop (due to starting current) that >will affect it is that of the battery itself - and that should be only a >fraction of the total voltage drop that the starter (or main bus) sees. > >In most cases, the EI units we use come from automotive applications. >Shouldn't we hook them up the way they were originally used, with a >separate connection to the battery, independent of the starter? And, for >that matter, the ground to the EI should be independent as well. > >And as for the failure mode, if the EI is on the battery directly, any >voltage low enough to make the EI misbehave is going to be so much more >lower at the starter, that the starter won't even be able to spin it >fast enough to light off the ignition anyway - ergo, no problem. > >-John There's nothing like DATA to help sort out questions. While we're pretty sure that a maintained RG battery will support 200-300A of cranking without dropping below 9v, I realized that we didn't account for starter inrush currents which are essentially the same as locked rotor current. Went out to the driveway with my hand-dandy data acquisition system and hooked it across the battery terminals of my GMC Safari. It's got the 4.3L V6 and a 32 a.h. RG battery. Results of the experiment can be downloaded from: http://www.aeroelectric.com/temp/Cranking.pdf Page 1 shows a simple turn-on-key-and-start scenario. The battery started at 13.0 volts and spiked downward to 9.42 volts on first application of starter power. Engine cranking loaded the battery to a range between 10.2 and 10.9 volts. Page 2 shows the effects of loading the battery first. I turned the key on, front A/C fan, Rear A/C fan, and then headlights before cranking the engine. Of course the fans are automatically shut down during cranking but the 7 seconds or so of pre-load on the battery produced an intital starter engagement spike that droped to 8.9 volts. This doesn't leave us much headroom. One would certainly want to run a picky EI system from a battery bus. This wouldn't eliminate the ground lead drop that would be significant on a rear mounted battery . . . (.3 to .5 volts) in a composite airplane. If your battery is mounted near the engine, then it seems likely that the EI system could be reasonably expected to see 9V+ for all phases of operation. Since the spike lasts only 50 milliseconds or so, an earlier suggestion about feeding power to the EI system via diode and electrolytic capacitor has merit. A 1 farad capacitor impressed with 1A of current flow produces a 1 volt per second rate of voltage change. A 12v battery with a diode feed would give you a capacitor charged to 11.5 volts through a diode before the starter hits. If we need to keep the EI system at or above 9v for let us say, 100 milliseconds using only capacitor stored energy as source, then we need to support 2A of current draw for 100 milliseconds with no more than 2.5 volts of change on the capacitor. This works out to 0.08 Farads. The automotive killer audio buffs have access to much larger capacitors as off-the-shelf items. I think 100,000 uF (0.1 Farads) are commonly available. Another solution would be to add a small (1 a.h. or so) SLA battery to the system that is wired to the EI system via a relay that opens during cranking so that the battery can carry the ignition system for starting. Batteries need maintenance, capacitors would be relatively maintenance free. Also, the diode is more robust than a relay. Bob . . . ________________________________________________________________________________
Date: Sep 04, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Electronic Ignitions
> >For the Light Speed ignition system the low voltage threshold is 8 volts >(per their >manual). This seems safely low, but with a Sky-Tech permanent magnet >starter I bust this >limit on every start. However, once the engine is "spinning" (with no >ignition source ON) >the bus voltage comes back up and I can engage the EI and have a >successful start. It does >not have to started on the mag. If have have the EI ON during initial >energizing of the >starter I invariably get a misfire--so I don't do dat--but had to learn >the hard way, since >the early manuals for the Light Speed don't really address this issue. I >got a nice >trouble-shooting chart from the tech people at Sky-Tech. My Concorde 25XC >battery is at the >aft most fuselage bulkhead of an RV-6 with a loooong cable run. Unless you've powered the EI system directly from the battery, long wire runs contribute significantly to voltage drop. Bob . . . ________________________________________________________________________________
Date: Sep 04, 2002
From: "Boyd C. Braem" <bcbraem(at)comcast.net>
Subject: Re: Keyed ignition and Z-27
In my old (1997-8) Light Speed manual it indicates that you can send your keyed ignition switch into Light Speed and they will modify it to work with their EI system. Otherwise, they rcommend a push button system. "Robert L. Nuckolls, III" wrote: > > > > > > >Hi Bob, > > > > In a previous post you said that the keyed ignition would not work with > >Z-27, dual alt, dual batt, one mag, one elect. ignition. I was under the > >impression Lightspeed made an electronic ignition that let you use the keyed > >ignition swith...Why wouldn't this work with Z-27? Thanks for the help! > > > >-- Brian S. > > There are ways to add a control lead to an electronic > ignition to make it compatible with magneto control > switches. If Lightspeed has done so -AND- you've got > a favorable disposition toward the keyswitch then > by all means . . . > > If your EI system is controlled by switching power > on and off via the ignition control switch, then > the keyswitch will not work. > > Bob . . . > ________________________________________________________________________________
From: David Chalmers <David(at)ChalmersFamily.com>
Subject: Keyed ignition and Z-27
Date: Sep 04, 2002
The Lightspeed II Plus (the plus costs extra) allows you to connect it like a magneto to your keyed ignition switch. Short the 'mag' wire to ground and it disables the ignition. In this state it draws negligible current so you can connect the power wires directly to the battery (through a fuse) - no power switch is required. David -----Original Message----- From: Boyd C. Braem [mailto:bcbraem(at)comcast.net] Subject: Re: AeroElectric-List: Keyed ignition and Z-27 In my old (1997-8) Light Speed manual it indicates that you can send your keyed ignition switch into Light Speed and they will modify it to work with their EI system. Otherwise, they rcommend a push button system. "Robert L. Nuckolls, III" wrote: > > > > > > >Hi Bob, > > > > In a previous post you said that the keyed ignition would not work with > >Z-27, dual alt, dual batt, one mag, one elect. ignition. I was under the > >impression Lightspeed made an electronic ignition that let you use the keyed > >ignition swith...Why wouldn't this work with Z-27? Thanks for the help! > > > >-- Brian S. > > There are ways to add a control lead to an electronic > ignition to make it compatible with magneto control > switches. If Lightspeed has done so -AND- you've got > a favorable disposition toward the keyswitch then > by all means . . . > > If your EI system is controlled by switching power > on and off via the ignition control switch, then > the keyswitch will not work. > > Bob . . . > http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
From: BAKEROCB(at)aol.com
Date: Sep 04, 2002
Subject: SS 100 degree CS 8 x 32 T20 Torx Screws
kisbuilders(at)angus.mystery.com, pulsar-builders(at)caseyk.org, Drshufly(at)aol.com, mrclary(at)erols.com, rkoehler(at)udc.edu, RODandKATE(at)erols.com 9/4/2002 Hello Fellow Builders, I have some bad news and some good news. The bad news is that I don't think the current supply of subject screws from Micro Fasteners is of adequate strength for structural purposes such as installing control surface hinges on composite aircraft. The good news is that John Fleisher hasn't given up on us. Let me explain. I bought a supply of the subject screws from MF and gave them a rudimentary comparative installation strength test. The test consisted of putting four separate AN 365 alloy steel nuts in a vise then screwing in one of four different 8 X 32 screws into each nut using a torque wrench until something failed. I will give the results for the four different screws below: A) Alloy steel MS24694 structual machine screw (minimum tensile strength of 125,000 PSI). Drive: Phillips. Failure torque: 32 in lbs. Remarks: Phillips bit cammed out of head, unable to tighten any further. B) 4037 high molybdenum steel alloy through hardened to surface Rockwell C 38-44 and having a tensile strength of 137-150 ksi. These screws were made per the reqts of ANSI/ASME B18.3 of 1986. Drive: 3/32 inch hex socket (Allen). Failure torque: 50 in lbs. Remarks: Screw socket stripped. (These screws were obtained from MF some time ago as a special order and were very expensive). C) 302 stainless steel, unhardened, with tensile strength of 85 ksi min. Made per the reqts of ANSI/ASME B18.3 of 1986. Drive: 3/32 inch hex socket (Allen). Failure torque: 30 in lbs. Remarks: Screw socket stripped. (These screws were obtained from MF some time ago as a special order and were very expensive). D) 302 stainless steel. Drive: Torx 20. Failure torque: 50 in lbs. Remarks: Screw head sheared off. Just obtained recently from MF. See further remarks below. Let me try to add some perspective / caveats to the above home grown tests. These are what I called "installation failure tests". The screws failed as I deliberately overstressed them with a torque wrench while simulating their installation. This does not mean that they would suffer installation failure as a person would install (or remove) them in a normal prudent manner. An "installation failure" is not the same as an "in service failure" in my terminology. For example if you installed non defective examples of either screw A) or screw B) satisfactorily in your structure and then that structure, while in service, placed a stress upon those screws they would obviously withstand a greater load than satisfactorily installed nondefective screws C) or D) simply by virtue of the material that they were made of aside from any design considerations. But I feel that screw D) does have a too high "in service failure" potential caused by its design.. I say this based on my examination of the sheared off screw head and shank. There just does not apprear to be enough material left between the screw shank and the screw head because of the size of the Torx 20 cavity. I do not plan to use them. Where do we go from here? I'm not sure. I've already alerted John Fleisher to my concerns and he has responded with an email that I have copied below. I have two recommendations: 1) Please pass this entire posting on to any group that you are a part of that may be interested in this subject and who will not see it through just this posting. 2) Let's let John work the problem for a while -- please be patient. Manufacturing and stocking issues are also very significant financial issues for small businessmen and they require some time to resolve. As a final point of this posting I would point out that there are standard specification structural fasteners (such as MS 24694 machine screws --Phillips drive) and non structural fasteners (such as MS 24693 machine screws -- Phillips drive) of various tensile strengths available to us as builders of amateur built experimental aircraft. What fasteners we choose to use and why we choose them are, within some bounds of reason and common sense, the choice of the individual builder. Please respect your fellow builder's prerogative to make that choice -- after all, he is an experimenter. Below my signature line follows the email that I received from John Fleisher. 'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - ?/?/? Subj: Re: 8-32x5/8 100 degree flat head torx screws Date: 09/04/2002 1:38:54 PM Eastern Daylight Time From: microfasteners(at)hotmail.com (John Fleisher) OC, I've been concerned about them since I got Camcar's technical book onTorx + and saw that they recommend a T15 for 8-32 flat heads and we used aT20. I had tried to twist them off here before then, and couldn't, so Irelaxed. I had asked our manufacturer before ordering them about the size, and he being less than the most communicative guy in the world said T20 was thelargest he could put on that head. When I spoke with him again today he saidT15 would be a lot easier. He's making up a new lot with the T15 heads andwe'll send you some in a week or two. Also of course we will replace any we have shipped, to you and to others. We continue to think that our guy is a competent mfr; this time around we'll get some verification of the quality before shipping them. Thanks for the headsup. John Micro Fasteners ________________________________________________________________________________
Date: Sep 04, 2002
From: Gary Liming <gary(at)liming.org>
Subject: Keyed ignition and Z-27
I just purchased a Lightspeed Plus II (so I can use the switch option - now don't start!) and Klaus told me he preferred that the ignition wire not even go through a fuse. Didn't say if it was the voltage drop he was concerned about, or if he just was worried about a nuisance trip, but I may fuse it anyway. Gary Liming > > > >The Lightspeed II Plus (the plus costs extra) allows you to connect it like >a magneto to your keyed ignition switch. Short the 'mag' wire to ground and >it disables the ignition. In this state it draws negligible current so you >can connect the power wires directly to the battery (through a fuse) - no >power switch is required. ________________________________________________________________________________
Date: Sep 04, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Keyed ignition and Z-27
> > >I just purchased a Lightspeed Plus II (so I can use the switch option - now >don't start!) and Klaus told me he preferred that the ignition wire not >even go through a fuse. Didn't say if it was the voltage drop he was >concerned about, or if he just was worried about a nuisance trip, but I may >fuse it anyway. > >Gary Liming Why not? You've got two ignition systems. If you get a nuisance trip, it's because your fuse/wire are too small . . . easily fixed. Bob . . . ________________________________________________________________________________
From: "Stucklen" <wstucklen1(at)cox.net>
Subject: Keyed ignition and Z-27
Date: Sep 04, 2002
Listers, Jeff Rose's system works just fine with a standard ignitions switch. I have my RV-6A wired this way. His system just shorts on wire on the magnetic pickup to ground through the ignition switch. Power to the EI still has to be shutoff. Fred Stucklen RV-6A N925RV 1997 hours of safe flying.... Subject: Re: Keyed ignition and Z-27 From: Robert L. Nuckolls, III (bob.nuckolls(at)cox.net) Date: Wed Sep 04 - 6:16 AM > > >Hi Bob, > > In a previous post you said that the keyed ignition would not work with >Z-27, dual alt, dual batt, one mag, one elect. ignition. I was under the >impression Lightspeed made an electronic ignition that let you use the keyed >ignition swith...Why wouldn't this work with Z-27? Thanks for the help! > >-- Brian S. There are ways to add a control lead to an electronic ignition to make it compatible with magneto control switches. If Lightspeed has done so -AND- you've got a favorable disposition toward the keyswitch then by all means . . . If your EI system is controlled by switching power on and off via the ignition control switch, then the keyswitch will not work. Bob . . . ________________________________________________________________________________
From: "Stucklen" <wstucklen1(at)cox.net>
Subject: Brownout" during cranking . . .
Date: Sep 04, 2002
Bob, I'm assuming from this statement you mean that the SLA battery would be in parallel with the main battery, but switched out of that parallel circuit only during starting. Is it OK to have this small battery charged in this manner (when not starting)? Could a condition exist that could cause an excessive changing condition to this battery? What would you recommend for the SLA battery? If this design architecture is acceptable, it could potentially simplify a dual EI system design..... Changing out BOTH batteries every two years should also prevent failures.... Fred Stucklen RV-6A N925RV 1997 hours of safe flying..... Subject: Re: Brownout" during cranking . . . From: Robert L. Nuckolls, III (bob.nuckolls(at)cox.net) Date: Wed Sep 04 - 6:53 AM Another solution would be to add a small (1 a.h. or so) SLA battery to the system that is wired to the EI system via a relay that opens during cranking so that the battery can carry the ignition system for starting. Batteries need maintenance, capacitors would be relatively maintenance free. Also, the diode is more robust than a relay. Bob . . . ________________________________________________________________________________
Date: Sep 04, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Brownout" during cranking . . .
> >Bob, > > I'm assuming from this statement you mean that the SLA battery would be >in parallel with the main battery, but switched out of that parallel >circuit only during starting. Is it OK to have this small battery >charged in this manner (when not starting)? Could a condition exist that >could cause an excessive changing condition to this battery? What would >you recommend for the SLA battery? > If this design architecture is acceptable, it could potentially >simplify a dual EI system design..... Changing out BOTH batteries every >two years should also prevent failures.... SLA (sealed lead-acid) is just another name for RG battery. "Starved electrolyte" and VRLA (vent regulated lead-acid) are other examples. See: http://www.panasonic.com/industrial/battery/oem/images/pdf/Panasonic_VRLA_LCR122R2P.pdf For a dual EI system, Figure Z-11 with a Z-30 add-on battery would get you two battery busses. With two batteries in parallel for cranking, brownout should not be an issue. The only reason we were even discussing a small, scabbed- on battery was to get around the brownout issues for those who want to take advantage of better starting with EI . . . Since the problem only lasts for milliseconds, perhaps a two battery arrangement is not necessary for a single EI + Mag. The diode-capacitor combo should work nicely and require close to zero maintenance. Once you add the second EI, then you would want to consider either two-battery/one-alternator or one-battery/two-alternator configurations. Figure Z-13 is very attractive from the perspective of low maintenance. You would still want to use a diode-capacitor brownout suppressor on both ignitions. If you have a vacuum system then most folks are stuck with one alternator. THEN I'd go with the second battery of a size equal to the main battery and do the one-new-battery- per-year rotation on them. Bob . . . ________________________________________________________________________________
From: Lenleg(at)aol.com
Date: Sep 05, 2002
Subject: Re: Wig Wag Light
Bob: I have installed the Wig Wag from Bob Haan in my 8A. The on-off switch is one of the buttons on my Infinity grip. I need to put a light on my console to let me know when the wig wag is on. Can you help me with that ? Len Leggette RV-8A N901LL (res) Greensboro, N.C. Any week now !!! ________________________________________________________________________________
From: KahnSG(at)aol.com
Date: Sep 05, 2002
Subject: RE:screws
Click here: Home http://www.phillips-screw.com/ http://www.phillips-screw.com/mortorq.htm Check out the sites above. The have various styles including the new aerospace MORTORQ. Steve ________________________________________________________________________________
Date: Sep 05, 2002
From: barry pote <barrypote(at)comcast.net>
Subject: wig wag and switches
Keeping with the Lectric Bob idea of keep it simple, I want to use as few switches as I can. Circumstances: 1. Two landing lights are installed. One of them aimed slightly down from the other, for different landing attitudes, but more importantly, to be used as a taxi light. 2. Bob Haan wigwag unit to be used on both lights during approach. 3. Just before landing, wig wag off. Both landing lights on. 4. Taxi with the one landing light (the one pointed down a little). First, is this a proper procedure? Second, How can I accomplish this with the fewest number of Bob's S700 switches? Barry Pote RV9a finishing ________________________________________________________________________________
Date: Sep 05, 2002
From: Gary Liming <gary(at)liming.org>
Subject: Dual, parallel batteries and chargers
From the Batteries Plus website: "Don't mix a new and old battery. This will draw more power from the new battery and shorten its life." They were referring to SLA batteries, not NiCds. How does fit in with the idea of swapping out one of two batteries each year? Does it simply presume that the battery that is kept for another year is not yet "old"? At my local store they offered a 17 ah Hawker SLA battery for $94.00 and an off brand SLA 17 ah for $65. I think there were some better alternatives, but I am not sure if they are still applicable. Anyone recommend a good source for them? Also, they offered a charger called a "Battery Tender", which they said was fool proof - it automatically switched from charge to trickle and wouldn't overcharge. They wanted $59.00 for it. Since I burned a steak yesterday by levaing on the grill too long after being distracted, I can see how frying an expensive battery could be something I'd do. Anyone have a better (cheaper) alternative for a charger? (I want a charger because it will be a while before the engine is operating regularly, and I would like to have a battery installed to check out actuators, avionics, etc. in the mean time.) Gary Liming ________________________________________________________________________________
From: "Marty Sailer" <sailer(at)epix.net>
Subject: Re:Battery Ground Wire
Date: Sep 05, 2002
----- I'm starting to wire my RV-6a and am considering running the negative battery cable (#4)to one of the lower engine mount bolts and a cable from the engine to the engine mount instead of drilling another hole in the firewall for a copper or brass bolt and 2 wires, one battery - firewall, one firewall - engine mount. Is this sound electrical practice? Marty Sailer ________________________________________________________________________________
From: "John Slade" <sladerj(at)bellsouth.net>
Subject: wig wag and switches
Date: Sep 05, 2002
> 2. Bob Haan wigwag unit to be used on both lights during approach. What's a wigwag unit??? ________________________________________________________________________________
From: "Shannon Knoepflein" <kycshann(at)kyol.net>
Subject: wig wag and switches
Date: Sep 05, 2002
Care to explain wig wag? --- Shannon Knoepflein <---> kycshann(at)kyol.net -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of barry pote Subject: AeroElectric-List: wig wag and switches Keeping with the Lectric Bob idea of keep it simple, I want to use as few switches as I can. Circumstances: 1. Two landing lights are installed. One of them aimed slightly down from the other, for different landing attitudes, but more importantly, to be used as a taxi light. 2. Bob Haan wigwag unit to be used on both lights during approach. 3. Just before landing, wig wag off. Both landing lights on. 4. Taxi with the one landing light (the one pointed down a little). First, is this a proper procedure? Second, How can I accomplish this with the fewest number of Bob's S700 switches? Barry Pote RV9a finishing = = = http://www.matronics.com/browselist/aeroelectric-list = ________________________________________________________________________________
From: mprather(at)spro.net
Subject: Re: wig wag and switches
Date: Sep 05, 2002
Wigwag is a term used to describe a lighting arrangement where 2 lights (or more, I suppose) are flashed alternately. This arrangement is especially useful because when the 2 lights are spaced some distance appart, the flashing behavior makes detecting them with the eye much easier. They create the illusion of motion. Wigwags are commonly seen on emergency vehicle (police cars) headlights, and airliner landing lights. Anectdotal data shows that visibility of vehicles with wigwag lighting are visible from at least twice the distance as compared to vehicles with steady burning lights. A circuit is required to provide the turn on/off of each light and regulate the timing. Sometimes the circuit is solid state and sometimes uses relays. The solid state circuits are nice because they have no moving parts, but will be generally less power efficient than circuits with relays. Whelen is a manufacturer of wigwags. Regards, Matt- ----- Original Message ----- From: "John Slade" <sladerj(at)bellsouth.net> Date: Thursday, September 5, 2002 2:02 pm Subject: RE: AeroElectric-List: wig wag and switches > > > 2. Bob Haan wigwag unit to be used on both lights during approach. > What's a wigwag unit??? > > > _- > - The AeroElectric-List Email Forum - ________________________________________________________________________________
Date: Sep 05, 2002
From: barry pote <barrypote(at)comcast.net>
Subject: Re: wig wag and switches
Bob Haan, an RV builder and manufacturer, and others, can supply a module that hooks to your landing lights. It turns them on and off, alternately. You use this in the pattern and it makes you very hard to miss seeing. It is similar to what the cops and ambulances use. Barry Pote Shannon Knoepflein wrote: > > > Care to explain wig wag? > > --- > ________________________________________________________________________________
Date: Sep 05, 2002
From: RSwanson <rswan19(at)comcast.net>
Subject: Re: Dual, parallel batteries and chargers
I have one of these which seems to operate correctly. It's $16.99. http://www.northerntool.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=210802 &prmenbr=6970 R ----- Original Message ----- From: "Gary Liming" <gary(at)liming.org> Subject: AeroElectric-List: Dual, parallel batteries and chargers > > > From the Batteries Plus website: > > "Don't mix a new and old battery. This will draw more power from the new > battery and shorten its life." They were referring to SLA batteries, not > NiCds. How does fit in with the idea of swapping out one of two batteries > each year? Does it simply presume that the battery that is kept for > another year is not yet "old"? > > At my local store they offered a 17 ah Hawker SLA battery for $94.00 and > an off brand SLA 17 ah for $65. I think there were some better > alternatives, but I am not sure if they are still applicable. Anyone > recommend a good source for them? > > Also, they offered a charger called a "Battery Tender", which they said was > fool proof - it automatically switched from charge to trickle and wouldn't > overcharge. They wanted $59.00 for it. Since I burned a steak yesterday > by levaing on the grill too long after being distracted, I can see how > frying an expensive battery could be something I'd do. Anyone have a > better (cheaper) alternative for a charger? (I want a charger because it > will be a while before the engine is operating regularly, and I would like > to have a battery installed to check out actuators, avionics, etc. in the > mean time.) > > Gary Liming > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
Date: Sep 05, 2002
From: Charlie and Tupper England <cengland(at)netdoor.com>
Subject: Re: Dual, parallel batteries and chargers
Gary Liming wrote: > > > From the Batteries Plus website: > > "Don't mix a new and old battery. This will draw more power from the new > battery and shorten its life." They were referring to SLA batteries, not > NiCds. How does fit in with the idea of swapping out one of two batteries > each year? Does it simply presume that the battery that is kept for > another year is not yet "old"? > > At my local store they offered a 17 ah Hawker SLA battery for $94.00 and > an off brand SLA 17 ah for $65. I think there were some better > alternatives, but I am not sure if they are still applicable. Anyone > recommend a good source for them? > > Also, they offered a charger called a "Battery Tender", which they said was > fool proof - it automatically switched from charge to trickle and wouldn't > overcharge. They wanted $59.00 for it. Since I burned a steak yesterday > by levaing on the grill too long after being distracted, I can see how > frying an expensive battery could be something I'd do. Anyone have a > better (cheaper) alternative for a charger? (I want a charger because it > will be a while before the engine is operating regularly, and I would like > to have a battery installed to check out actuators, avionics, etc. in the > mean time.) > > Gary Liming > http://www.harborfreight.com/cpi/ctaf/headsearch.taf?function=Search http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=42292 I have no personal experience with this product; I just noticed that it is currently on sale in their stores. Charlie ________________________________________________________________________________
From: "Jerry Carter" <jcarter8(at)midsouth.rr.com>
Subject: Electrical Gyros For Sale
Date: Sep 05, 2002
I'm selling my two R.C. Allen 3 1/8" electrical gyros due to my latest panel redesign. The DG and horizon have both been in service and run regularly until being removed from my airplane two weeks ago. The DG was purchased on 9-21-01, the horizon on 8-28-00. The horizon has the 8 degree panel tilt adjustment needed for RV's and is placarded as such by the manufacturer. There is no manufacturer's warranty, although I will warranty each for thirty days to allow the purchaser to inspect the instruments. Each is supplied with the required connector, so all one has to do is splice the power and ground wires. New price for these instruments is over $1,850 each. I'm asking $1,500.00 each, buyer pays shipping. E-mail me for any questions. Jerry Carter RV-8A 155 hrs ________________________________________________________________________________
From: mprather(at)spro.net
Subject: Re: Dual, parallel batteries and chargers
Date: Sep 05, 2002
I don't think this comment refers to any kind of architecture in which two batteries are used to provide extra redundancy. The circuits that Bob has described and drawn in ApdxZ that have 2 batteries are only wired together in that they are in the same circuit. The circuits have diodes and contactors to seperate them - especially when any one item is misbehaving. If multiple batteries were to be wired together with the sole intent being to increase the Ah capacity of storage, then I think their recommendation to not mix battery ages makes sense. However, I still think this type of design is poor because it doesn't take advantage of the relatively cheap redundancy that an isolator can provide. In fact, I think I could argue that wiring two batteries together decreases overall reliability. This is so because a failure in either battery can jeopardize the perfomance of the whole system. Regards, Matt- ----- Original Message ----- From: Gary Liming <gary(at)liming.org> Date: Thursday, September 5, 2002 1:11 pm Subject: AeroElectric-List: Dual, parallel batteries and chargers > > > From the Batteries Plus website: > > "Don't mix a new and old battery. This will draw more power from > the new > battery and shorten its life." They were referring to SLA > batteries, not > NiCds. How does fit in with the idea of swapping out one of two > batteries > each year? Does it simply presume that the battery that is kept > for > another year is not yet "old"? ________________________________________________________________________________
Date: Sep 05, 2002
From: Gary Liming <gary(at)liming.org>
Subject: Re: Dual, parallel batteries and chargers
> > >I don't think this comment refers to any kind of architecture in >which two batteries are used to provide extra redundancy. You're right - the comment didn't refer to Bob's Z drawings - I thought there was somebody a while ago asking questions about parallel batteries. >In fact, I think I could argue that wiring two batteries >together decreases overall reliability. I think if you did argue that, you'd be right, including the added (un)reliability of the connectors and wire between them. The other two gentlemen who recommended the $18 chargers - they don't do a full charge, and then cut over to trickle, like the one described. (but thanks for the repsonse) I think this feature is sometimes called an "automatic" charger on some models. Anyway, I checked the archives and soem of the links provided for battery sources are now dead - can somebody recommend a good source for 17ah batteries? Thanks, Gary Liming ________________________________________________________________________________
From: "Pat Hatch" <pat_hatch(at)msn.com>
Subject: Re: Dual, parallel batteries and chargers
Date: Sep 05, 2002
Gary, I used two Panasonic SLA 17 a.h. batteries out of Digi-Key, p/n P174-ND at $36.23 each (page 897 in the current catalog). Been in the airplane for at least 6 months, during the building, testing, total of about 30 hours flight time now, no problems. By the way, I have dual Jeff Rose E.I. units. I start on one battery, and select the E.I.'s on the other. Then I alternate each day. Let me know if you need further details. Pat Hatch RV-4, N17PH, 700 hrs O-320, Hartzell C/S RV-6, N44PH, 30 hrs O-360, Hartzell C/S Vero Beach, FL ----- Original Message ----- From: "Gary Liming" <gary(at)liming.org> Subject: Re: AeroElectric-List: Dual, parallel batteries and chargers > > > > > > >I don't think this comment refers to any kind of architecture in > >which two batteries are used to provide extra redundancy. > > You're right - the comment didn't refer to Bob's Z drawings - I thought > there was somebody a while ago asking questions about parallel batteries. > > >In fact, I think I could argue that wiring two batteries > >together decreases overall reliability. > > I think if you did argue that, you'd be right, including the added > (un)reliability of the connectors and wire between them. > > The other two gentlemen who recommended the $18 chargers - they don't do a > full charge, and then cut over to trickle, like the one described. (but > thanks for the repsonse) I think this feature is sometimes called an > "automatic" charger on some models. > > Anyway, I checked the archives and soem of the links provided for battery > sources are now dead - can somebody recommend a good source for 17ah batteries? > > Thanks, > > Gary Liming > > http://www.matronics.com/browselist/aeroelectric-list > ________________________________________________________________________________
Date: Sep 05, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Dual, parallel batteries and chargers
> > > From the Batteries Plus website: > >"Don't mix a new and old battery. This will draw more power from the new >battery and shorten its life." B.S. > They were referring to SLA batteries, not >NiCds. How does fit in with the idea of swapping out one of two batteries >each year? Does it simply presume that the battery that is kept for >another year is not yet "old"? Standard information given out to people who don't and may never understand what they're trying to accomplish with battery maintenance. >At my local store they offered a 17 ah Hawker SLA battery for $94.00 and >an off brand SLA 17 ah for $65. I think there were some better >alternatives, but I am not sure if they are still applicable. Anyone >recommend a good source for them? $65 is about the going rate for over the counter 17 a.h. batteries . . . I've seen them cheaper on the 'net but by the time you add shipping, they'll cost you more. >Also, they offered a charger called a "Battery Tender", which they said was >fool proof - it automatically switched from charge to trickle and wouldn't >overcharge. They wanted $59.00 for it. Since I burned a steak yesterday >by levaing on the grill too long after being distracted, I can see how >frying an expensive battery could be something I'd do. Anyone have a >better (cheaper) alternative for a charger? (I want a charger because it >will be a while before the engine is operating regularly, and I would like >to have a battery installed to check out actuators, avionics, etc. in the >mean time.) For little more money than the tender/charger, you can buy a regulated power supply good for 20A that makes a DANDY ground power supply for checking systems in the shop. Don't buy a battery until first flight (use a junker to crank engine for other testing). See: http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F008%5F001%5F000%5F000&product%5Fid=910%2D0448 I wouldn't have an airplane that wasn't fitted with a means for attaching ground maintenance and test power. Otherwise, consider that RG batteries have a very low self discharge rate. I have readers that store their airplanes all winter long and they're quite willing to start next spring. Further, I presume now that because you OWN an airplane of your own creation, you INTEND to fly more often than when you rented airplanes. "Tending" batteries in RG fitted airplanes flown more than 4 times a year is a non-issue. Buy 'em cheap, change them often, and spend that tender/charger money on fuel to go someplace interesting. Bob . . . |-------------------------------------------------------| | There is a great difference between knowing and | | understanding: you can know a lot about something and | | not really understand it. -C.F. Kettering- | |-------------------------------------------------------| ________________________________________________________________________________
Date: Sep 05, 2002
From: Gary Liming <gary(at)liming.org>
Subject: Re: Dual, parallel batteries and
chargers > >Also, they offered a charger called a "Battery Tender", which they said was > >fool proof - it automatically switched from charge to trickle and wouldn't > >overcharge. They wanted $59.00 for it. Since I burned a steak yesterday > >by levaing on the grill too long after being distracted, I can see how > >frying an expensive battery could be something I'd do. Anyone have a > >better (cheaper) alternative for a charger? (I want a charger because it > >will be a while before the engine is operating regularly, and I would like > >to have a battery installed to check out actuators, avionics, etc. in the > >mean time.) > > For little more money than the tender/charger, you can buy a > regulated power supply good for 20A that makes a DANDY ground > power supply for checking systems in the shop. Don't buy > a battery until first flight (use a junker to crank engine > for other testing). See: > > >http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F008%5F001%5F000%5F000&product%5Fid=910%2D0448 Well, I think the idea of a bench supply instead of a charger is a good one. The above link says they're out of stock, though A smaller (14A) which happened to be the same money as the charger, was also out of stock. Sigh. I know of some other sources for bench supplies, though. Thanks for the idea! I already have a variable supply, but not for that much current, and I don't really want to take it out of the bench it has settled into. Gary Liming ________________________________________________________________________________
Date: Sep 05, 2002
From: Sam Buchanan <sbuc(at)hiwaay.net>
Subject: Re: wig wag and switches
mprather(at)spro.net wrote: > > > Wigwag is a term used to describe a lighting arrangement where > 2 lights (or more, I suppose) are flashed alternately. This > arrangement is especially useful because when the 2 lights are > spaced some distance appart, the flashing behavior makes detecting > them with the eye much easier. They create the illusion of motion. > Wigwags are commonly seen on emergency vehicle (police cars) > headlights, and airliner landing lights. Anectdotal data shows that > visibility of vehicles with wigwag lighting are visible from at least > twice the distance as compared to vehicles with steady burning lights. > > A circuit is required to provide the turn on/off of each light > and regulate the timing. Sometimes the circuit is solid state > and sometimes uses relays. The solid state circuits are nice > because they have no moving parts, but will be generally less > power efficient than circuits with relays. > > Whelen is a manufacturer of wigwags. > > Regards, > > Matt- > Or.......you can use what the emergency vehicles use. Here is a link that shows the installation of a Galls flasher in my RV-6: http://home.hiwaay.net/~sbuc/journal/panel4.html Scroll down to near the bottom of the page. The unit works great and has prompted MANY comments on the enhanced visibility. Sam Buchanan (RV-6, 418 hrs) "The RV Journal" http://thervjournal.com ________________________________________________________________________________
Date: Sep 05, 2002
From: John Rourke <john@allied-computer.com>
Subject: Re: Dual, parallel batteries and chargers
Check out this one: http://www.etronics.com/product.asp?stk_code=pyrps26kx&svbname=16 Same price, in stock, 22/25 Amps, adjustable voltage 6-15Vdc, electronic overload and crowbar overvoltage protection... The only thing is, it's Pyramid brand, I don't know how they are today and with this line, but years ago I had some audio equipment of theirs that wasn't that great... anyone else know about this brand? -John Gary Liming wrote: > > >>>Also, they offered a charger called a "Battery Tender", which they said was >>>fool proof - it automatically switched from charge to trickle and wouldn't >>>overcharge. They wanted $59.00 for it. Since I burned a steak yesterday >>>by levaing on the grill too long after being distracted, I can see how >>>frying an expensive battery could be something I'd do. Anyone have a >>>better (cheaper) alternative for a charger? (I want a charger because it >>>will be a while before the engine is operating regularly, and I would like >>>to have a battery installed to check out actuators, avionics, etc. in the >>>mean time.) >>> >> For little more money than the tender/charger, you can buy a >> regulated power supply good for 20A that makes a DANDY ground >> power supply for checking systems in the shop. Don't buy >> a battery until first flight (use a junker to crank engine >> for other testing). See: >> >> >>http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F008%5F001%5F000%5F000&product%5Fid=910%2D0448 >> > > Well, I think the idea of a bench supply instead of a charger is a good > one. The above link says they're out of stock, though A smaller (14A) > which happened to be the same money as the charger, was also out of > stock. Sigh. I know of some other sources for bench supplies, > though. Thanks for the idea! I already have a variable supply, but not > for that much current, and I don't really want to take it out of the bench > it has settled into. > > Gary Liming > > > > > > > > > ________________________________________________________________________________
Date: Sep 05, 2002
From: Jaye and Scott Jackson <jayeandscott(at)shaw.ca>
Subject: encoder error
Anyone know why a new encoder would consistently report an altitude 500' low? I figure the 500' would mean that I wired it up wrong to the transponder,but it appears to be correct. Does the adjustment screws have this much corrective ability. Which one do I turn, the Hi or the Lo, and which way? Thanks again, Scott in Vancouver ________________________________________________________________________________
Date: Sep 05, 2002
Subject: Re: Brownout" during cranking...
From: czechsix(at)juno.com
Bob, Thanks for the data Bob. Just wondering if anyone has asked Klaus Savier at Lightspeed about this though? His specs (at least for the systems he currently sells) state that it will operate over a voltage range of 4 to 35 volts. See the specs on his website at: http://www.lsecorp.com/Products/IgnitionSpecs.htm So dropping to 8 or 9 volts momentarily on starting should never even come close to messing up the Lightspeed system, right?? If this is causing people trouble I'd contact Klaus because this would mean either his system isn't meeting spec or else there's a different problem occurring... --Mark Navratil Cedar Rapids, Iowa RV-8A N2D equipped with dual crank-triggered Lightspeed Plasma II ignition system (but not running yet...) - From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: AeroElectric-List: Re: Brownout" during cranking . . . There's nothing like DATA to help sort out questions. While we're pretty sure that a maintained RG battery will support 200-300A of cranking without dropping below 9v, I realized that we didn't account for starter inrush currents which are essentially the same as locked rotor current. Went out to the driveway with my hand-dandy data acquisition system and hooked it across the battery terminals of my GMC Safari. It's got the 4.3L V6 and a 32 a.h. RG battery. Results of the experiment can be downloaded from: http://www.aeroelectric.com/temp/Cranking.pdf Page 1 shows a simple turn-on-key-and-start scenario. The battery started at 13.0 volts and spiked downward to 9.42 volts on first application of starter power. Engine cranking loaded the battery to a range between 10.2 and 10.9 volts. Page 2 shows the effects of loading the battery first. I turned the key on, front A/C fan, Rear A/C fan, and then headlights before cranking the engine. Of course the fans are automatically shut down during cranking but the 7 seconds or so of pre-load on the battery produced an intital starter engagement spike that droped to 8.9 volts. This doesn't leave us much headroom. One would certainly want to run a picky EI system from a battery bus. This wouldn't eliminate the ground lead drop that would be significant on a rear mounted battery . . . (.3 to .5 volts) in a composite airplane. If your battery is mounted near the engine, then it seems likely that the EI system could be reasonably expected to see 9V+ for all phases of operation. Since the spike lasts only 50 milliseconds or so, an earlier suggestion about feeding power to the EI system via diode and electrolytic capacitor has merit. A 1 farad capacitor impressed with 1A of current flow produces a 1 volt per second rate of voltage change. A 12v battery with a diode feed would give you a capacitor charged to 11.5 volts through a diode before the starter hits. If we need to keep the EI system at or above 9v for let us say, 100 milliseconds using only capacitor stored energy as source, then we need to support 2A of current draw for 100 milliseconds with no more than 2.5 volts of change on the capacitor. This works out to 0.08 Farads. The automotive killer audio buffs have access to much larger capacitors as off-the-shelf items. I think 100,000 uF (0.1 Farads) are commonly available. Another solution would be to add a small (1 a.h. or so) SLA battery to the system that is wired to the EI system via a relay that opens during cranking so that the battery can carry the ignition system for starting. Batteries need maintenance, capacitors would be relatively maintenance free. Also, the diode is more robust than a relay. Bob . . . ________________________________________________________________________________
Date: Sep 05, 2002
From: "Jim Pack" <jpack(at)igs3.com>
Subject: Electronic Ignition
For those of you that have 1 Mag / 1 Electronic Ignition, When preparing to start, do you turn on the Alt/Bat before or after you turn on the mag & EI? Or does it matter? I'm planning the panel and want to put the switches in a reasonable order. ________________________________________________________________________________
From: "Wayne Sweet" <wsweet(at)attbi.com>
Subject: Re: Electronic Ignition
Date: Sep 06, 2002
I had installed prior to engine overhaul (and warrantee period) a LSE CDI in place of the right mag. I have individual switches for each "mag" and turned both on to start. Of course the start was nearly instantaneous; the CDI system made for quick starts and smooth idle. Wayne ----- Original Message ----- From: "Jim Pack" <jpack(at)igs3.com> Subject: AeroElectric-List: Electronic Ignition > > For those of you that have 1 Mag / 1 Electronic Ignition, When > preparing to start, do you turn on the Alt/Bat before or after you turn > on the mag & EI? Or does it matter? > > I'm planning the panel and want to put the switches in a reasonable > order. > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Jim Robinson" <jbr(at)hitechnetworks.net>
Date: Sep 06, 2002
Subject: Re: Brownout" during cranking...
Mark I had a single LightSpeed setup on my G1 and it started on the electronic ign with almost instant starts. Never had a problem with starting. I even had the big lyc starter. I am also going with the same dual electronics on my new airplane with the crank trigger. From my past experience I see no problem. Jim Robinson Glll n79R (almost done) > > Bob, > > Thanks for the data Bob. Just wondering if anyone has asked Klaus > Savier at Lightspeed about this though? His specs (at least for the > systems he currently sells) state that it will operate over a voltage > range of 4 to 35 volts. See the specs on his website at: > http://www.lsecorp.com/Products/IgnitionSpecs.htm So dropping to 8 or > 9 volts momentarily on starting should never even come close to > messing up the Lightspeed system, right?? If this is causing people > trouble I'd contact Klaus because this would mean either his system > isn't meeting spec or else there's a different problem occurring... > > --Mark Navratil > Cedar Rapids, Iowa > RV-8A N2D equipped with dual crank-triggered Lightspeed Plasma II > ignition system (but not running yet...) - > > From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> > Subject: AeroElectric-List: Re: Brownout" during cranking . . . > > > > There's nothing like DATA to help sort out questions. > While we're pretty sure that a maintained RG battery > will support 200-300A of cranking without dropping below > 9v, I realized that we didn't account for starter inrush > currents which are essentially the same as locked rotor > current. > > Went out to the driveway with my hand-dandy data > acquisition system and hooked it across the battery > terminals of my GMC Safari. It's got the 4.3L > V6 and a 32 a.h. RG battery. > > Results of the experiment can be downloaded > from: > > http://www.aeroelectric.com/temp/Cranking.pdf > > Page 1 shows a simple turn-on-key-and-start > scenario. The battery started at 13.0 volts > and spiked downward to 9.42 volts on first > application of starter power. Engine cranking > loaded the battery to a range between 10.2 and > 10.9 volts. > > Page 2 shows the effects of loading the battery > first. I turned the key on, front A/C fan, > Rear A/C fan, and then headlights before cranking > the engine. Of course the fans are automatically > shut down during cranking but the 7 seconds or > so of pre-load on the battery produced an intital > starter engagement spike that droped to 8.9 volts. > > This doesn't leave us much headroom. One would > certainly want to run a picky EI system from a > battery bus. This wouldn't eliminate the ground > lead drop that would be significant on a rear > mounted battery . . . (.3 to .5 volts) in a > composite airplane. > > If your battery is mounted near the engine, then > it seems likely that the EI system could be > reasonably expected to see 9V+ for all phases > of operation. > > Since the spike lasts only 50 milliseconds or > so, an earlier suggestion about feeding power > to the EI system via diode and electrolytic > capacitor has merit. A 1 farad capacitor > impressed with 1A of current flow produces > a 1 volt per second rate of voltage change. > > A 12v battery with a diode feed would give you > a capacitor charged to 11.5 volts through a > diode before the starter hits. > > If we need to keep the EI system at or above > 9v for let us say, 100 milliseconds using > only capacitor stored energy as source, then > we need to support 2A of current draw for 100 > milliseconds with no more than 2.5 volts of > change on the capacitor. This works out to > 0.08 Farads. The automotive killer audio > buffs have access to much larger capacitors > as off-the-shelf items. I think 100,000 uF > (0.1 Farads) are commonly available. > > Another solution would be to add a small > (1 a.h. or so) SLA battery to the system > that is wired to the EI system via a relay > that opens during cranking so that the battery > can carry the ignition system for starting. > Batteries need maintenance, capacitors would > be relatively maintenance free. Also, the diode > is more robust than a relay. > > Bob . . . > > > direct advertising on the Matronics Forums. > List members. > http://www.matronics.com/ > === > > > ________________________________________________________________________________
From: "Dennis O'Connor" <doconnor(at)chartermi.net>
Subject: Re: Dual, parallel batteries and chargers
Date: Sep 06, 2002
The vast majority of "trickle chargers", even the so called regulated chargers, overcharge the battery (actually, they hold it at too high a voltage) and cause out gassing and loss of electrolyte... The typical 1 amp trickle charger will boil a battery dry if left unattended for long periods, and especially a small battery with thin plates as are used for aircraft... Better chargers designed to be left running 24/7 that limit the trickle voltage and current below the level of gassing, i.e. below 14 volts, can be found at RV dealers, etc., but tend to be expensive, because quality costs money... However, you can inexpensively fix up your own charger with just a bit of effort... Buy a cheap, unregulated, 1 amp charger at the auto store, or farm store, etc.. These are usually in the $20 range... Leave it charging the battery for a day, just so that you are sure the battery is fully charged... Then use your volt meter to measure the DC voltage across the battery terminals with the charger turned on... It will be considerably above 14 volts... The idea is to reduce the 120 vac input to the charger to the point that the battery charger output is floating in the 13.0 - 13.5 volts DC range... Get a light dimmer, plug the charger into it and adjust the dimmer until the charger output voltage is where you want it (while it is attached to the battery)... Be aware that the battery will act like a reservoir/capacitor, so that the voltage at the battery terminals will not change rapidly with small adjustments of the dimmer... Be patient... Make an adjustment and leave it for an hour and recheck, etc... This will not work with regulated trickle chargers as lowering the input voltage will cause them to malfunction... Another method to lower the line voltage would be a light bulb socket wired in series with the charger input... Try different wattage bulbs in it to change the voltage... Cheers ... Denny ----- Original Message ----- From: "Gary Liming" <gary(at)liming.org> Subject: Re: AeroElectric-List: Re: Dual, parallel batteries and chargers > > > > >Also, they offered a charger called a "Battery Tender", which they said was > > >fool proof - it automatically switched from charge to trickle and wouldn't > > >overcharge. They wanted $59.00 for it. Since I burned a steak yesterday > > >by levaing on the grill too long after being distracted, I can see how > > >frying an expensive battery could be something I'd do. Anyone have a > > >better (cheaper) alternative for a charger? (I want a charger because it > > >will be a while before the engine is operating regularly, and I would like > > >to have a battery installed to check out actuators, avionics, etc. in the > > >mean time.) > > > > For little more money than the tender/charger, you can buy a > > regulated power supply good for 20A that makes a DANDY ground > > power supply for checking systems in the shop. Don't buy > > a battery until first flight (use a junker to crank engine > > for other testing). See: > > > > > >http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=C TLG%5F008%5F001%5F000%5F000&product%5Fid=910%2D0448 > > Well, I think the idea of a bench supply instead of a charger is a good > one. The above link says they're out of stock, though A smaller (14A) > which happened to be the same money as the charger, was also out of > stock. Sigh. I know of some other sources for bench supplies, > though. Thanks for the idea! I already have a variable supply, but not > for that much current, and I don't really want to take it out of the bench > it has settled into. > > Gary Liming > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Cy Galley" <cgalley(at)qcbc.org>
Subject: Re: Dual, parallel batteries and chargers
Date: Sep 06, 2002
Another item that will work with your trickle charger, use a lamp timer and only charge an hour a day. Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh Editor, EAA Safety Programs cgalley(at)qcbc.org or experimenter(at)eaa.org Always looking for articles for the Experimenter ----- Original Message ----- From: "Dennis O'Connor" <doconnor(at)chartermi.net> Subject: Re: AeroElectric-List: Re: Dual, parallel batteries and chargers > > The vast majority of "trickle chargers", even the so called regulated > chargers, overcharge the battery (actually, they hold it at too high a > voltage) and cause out gassing and loss of electrolyte... The typical 1 amp > trickle charger will boil a battery dry if left unattended for long periods, > and especially a small battery with thin plates as are used for aircraft... > Better chargers designed to be left running 24/7 that limit the trickle > voltage and current below the level of gassing, i.e. below 14 volts, can be > found at RV dealers, etc., but tend to be expensive, because quality costs > money... > However, you can inexpensively fix up your own charger with just a bit of > effort... Buy a cheap, unregulated, 1 amp charger at the auto store, or > farm store, etc.. These are usually in the $20 range... Leave it charging > the battery for a day, just so that you are sure the battery is fully > charged... Then use your volt meter to measure the DC voltage across the > battery terminals with the charger turned on... It will be considerably > above 14 volts... > The idea is to reduce the 120 vac input to the charger to the point that the > battery charger output is floating in the 13.0 - 13.5 volts DC range... Get > a light dimmer, plug the charger into it and adjust the dimmer until the > charger output voltage is where you want it (while it is attached to the > battery)... Be aware that the battery will act like a reservoir/capacitor, > so that the voltage at the battery terminals will not change rapidly with > small adjustments of the dimmer... Be patient... Make an adjustment and > leave it for an hour and recheck, etc... > This will not work with regulated trickle chargers as lowering the input > voltage will cause them to malfunction... > > Another method to lower the line voltage would be a light bulb socket wired > in series with the charger input... Try different wattage bulbs in it to > change the voltage... > > Cheers ... Denny > ----- Original Message ----- > From: "Gary Liming" <gary(at)liming.org> > To: > Subject: Re: AeroElectric-List: Re: Dual, parallel batteries and chargers > > > > > > > > > >Also, they offered a charger called a "Battery Tender", which they said > was > > > >fool proof - it automatically switched from charge to trickle and > wouldn't > > > >overcharge. They wanted $59.00 for it. Since I burned a steak > yesterday > > > >by levaing on the grill too long after being distracted, I can see how > > > >frying an expensive battery could be something I'd do. Anyone have a > > > >better (cheaper) alternative for a charger? (I want a charger because > it > > > >will be a while before the engine is operating regularly, and I would > like > > > >to have a battery installed to check out actuators, avionics, etc. in > the > > > >mean time.) > > > > > > For little more money than the tender/charger, you can buy a > > > regulated power supply good for 20A that makes a DANDY ground > > > power supply for checking systems in the shop. Don't buy > > > a battery until first flight (use a junker to crank engine > > > for other testing). See: > > > > > > > > > >http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=C > TLG%5F008%5F001%5F000%5F000&product%5Fid=910%2D0448 > > > > Well, I think the idea of a bench supply instead of a charger is a good > > one. The above link says they're out of stock, though A smaller (14A) > > which happened to be the same money as the charger, was also out of > > stock. Sigh. I know of some other sources for bench supplies, > > though. Thanks for the idea! I already have a variable supply, but not > > for that much current, and I don't really want to take it out of the bench > > it has settled into. > > > > Gary Liming > > > > > > > > > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: jerry(at)tr2.com
Subject: Re: Dual, parallel batteries and chargers
Date: Sep 06, 2002
Dennis O'Connor wrote: > > > The vast majority of "trickle chargers", even the so called regulated > chargers, overcharge the battery (actually, they hold it at too high a > voltage) and cause out gassing and loss of electrolyte... The typical 1 amp > trickle charger will boil a battery dry if left unattended for long periods, *** Even a tiny 200mA - 100mA - even 50mA charge will boil a battery dry if you leave it on long enough. Been there, done that. > and especially a small battery with thin plates as are used for aircraft... > Better chargers designed to be left running 24/7 that limit the trickle > voltage and current below the level of gassing, i.e. below 14 volts, can be > found at RV dealers, etc., but tend to be expensive, because quality costs > money... *** I think "smart" chargers are getting cheaper. See http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=41288 ( Remember, this is *electronics* - one of the few things in life that gets cheaper with time ) > However, you can inexpensively fix up your own charger with just a bit of > effort... Buy a cheap, unregulated, 1 amp charger at the auto store, or > The idea is to reduce the 120 vac input to the charger to the point that the > battery charger output is floating in the 13.0 - 13.5 volts DC range... Get > a light dimmer, *** Unfortunately, the AC line voltage varies considerably. I don't think you can reliably attain "voltage mode" charging without some form of regulator. I have a cheap 10A charger that I use on the ramp. Depending on the AC line voltage, I may get anything from 5A to 10A, on an identically charged battery. - Jerry Kaidor ( jerry(at)tr2.com ) ________________________________________________________________________________
From: Ken Harrill <KHarrill(at)osa.state.sc.us>
Subject: Re: Brownout" during cranking...
Date: Sep 06, 2002
I have a Lightspeed EI and a mag without an impulse coupling, so I always start on the EI. I also have separate toggle switches for each ignition system and a push button starter. My starting procedure is to press and hold the starter button then switch on the EI. At 75 hours I have experienced no kick back or starting problems. The battery is still relatively fresh, so problems could show up later when the battery starts showing some age. Ken Harrill RV-6 If your battery is mounted near the engine, then it seems likely that the EI system could be reasonably expected to see 9V+ for all phases of operation. Since the spike lasts only 50 milliseconds or so, an earlier suggestion about feeding power to the EI system via diode and electrolytic capacitor has merit. A 1 farad capacitor impressed with 1A of current flow produces a 1 volt per second rate of voltage change. A 12v battery with a diode feed would give you a capacitor charged to 11.5 volts through a diode before the starter hits. If we need to keep the EI system at or above 9v for let us say, 100 milliseconds using only capacitor stored energy as source, then we need to support 2A of current draw for 100 milliseconds with no more than 2.5 volts of change on the capacitor. This works out to 0.08 Farads. The automotive killer audio buffs have access to much larger capacitors as off-the-shelf items. I think 100,000 uF (0.1 Farads) are commonly available. Another solution would be to add a small (1 a.h. or so) SLA battery to the system that is wired to the EI system via a relay that opens during cranking so that the battery can carry the ignition system for starting. Batteries need maintenance, capacitors would be relatively maintenance free. Also, the diode is more robust than a relay. Bob . . . http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
Date: Sep 06, 2002
From: "Boyd C. Braem" <bcbraem(at)comcast.net>
Subject: Re: Brownout" during cranking...
I know what the specs say, but if you go into "Manuals" and then into "Trouble Shooting" and then "Starting Problems" it says that the Light Speed (I, II & II Plus) will provide an "accurate spark" as long as the input voltage is above 8 volts. When the original Light Speed EI went into the Super 6 it was one of the first 6-cyl installations and as the manual was not fully fleshed out at that time, our working "manual" was a telephone with Klaus at the other end of the line. After following this thread and checking the current wiring diagrams, I can see that a few changes are needed in my installation to correctly bring it up to "modern" standards. I like the idea of the capacitor (1 farad) and diode. Is the IN5400 diode a good choice for this application? When my mag craps out and I add the second EI, I'll be going to dual batteries. czechsix(at)juno.com wrote: > > Bob, > > Thanks for the data Bob. Just wondering if anyone has asked Klaus Savier > at Lightspeed about this though? His specs (at least for the systems he > currently sells) state that it will operate over a voltage range of 4 to > 35 volts. See the specs on his website at: > http://www.lsecorp.com/Products/IgnitionSpecs.htm So dropping to 8 or 9 > volts momentarily on starting should never even come close to messing up > the Lightspeed system, right?? If this is causing people trouble I'd > contact Klaus because this would mean either his system isn't meeting > spec or else there's a different problem occurring... > > --Mark Navratil > Cedar Rapids, Iowa > RV-8A N2D equipped with dual crank-triggered Lightspeed Plasma II > ignition system (but not running yet...) > - > > From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> > Subject: AeroElectric-List: Re: Brownout" during cranking . . . > > > > There's nothing like DATA to help sort out questions. > While we're pretty sure that a maintained RG battery > will support 200-300A of cranking without dropping below > 9v, I realized that we didn't account for starter inrush > currents which are essentially the same as locked rotor > current. > > Went out to the driveway with my hand-dandy data > acquisition system and hooked it across the battery > terminals of my GMC Safari. It's got the 4.3L > V6 and a 32 a.h. RG battery. > > Results of the experiment can be downloaded > from: > > http://www.aeroelectric.com/temp/Cranking.pdf > > Page 1 shows a simple turn-on-key-and-start > scenario. The battery started at 13.0 volts > and spiked downward to 9.42 volts on first > application of starter power. Engine cranking > loaded the battery to a range between 10.2 and > 10.9 volts. > > Page 2 shows the effects of loading the battery > first. I turned the key on, front A/C fan, > Rear A/C fan, and then headlights before cranking > the engine. Of course the fans are automatically > shut down during cranking but the 7 seconds or > so of pre-load on the battery produced an intital > starter engagement spike that droped to 8.9 volts. > > This doesn't leave us much headroom. One would > certainly want to run a picky EI system from a > battery bus. This wouldn't eliminate the ground > lead drop that would be significant on a rear > mounted battery . . . (.3 to .5 volts) in a > composite airplane. > > If your battery is mounted near the engine, then > it seems likely that the EI system could be > reasonably expected to see 9V+ for all phases > of operation. > > Since the spike lasts only 50 milliseconds or > so, an earlier suggestion about feeding power > to the EI system via diode and electrolytic > capacitor has merit. A 1 farad capacitor > impressed with 1A of current flow produces > a 1 volt per second rate of voltage change. > > A 12v battery with a diode feed would give you > a capacitor charged to 11.5 volts through a > diode before the starter hits. > > If we need to keep the EI system at or above > 9v for let us say, 100 milliseconds using > only capacitor stored energy as source, then > we need to support 2A of current draw for 100 > milliseconds with no more than 2.5 volts of > change on the capacitor. This works out to > 0.08 Farads. The automotive killer audio > buffs have access to much larger capacitors > as off-the-shelf items. I think 100,000 uF > (0.1 Farads) are commonly available. > > Another solution would be to add a small > (1 a.h. or so) SLA battery to the system > that is wired to the EI system via a relay > that opens during cranking so that the battery > can carry the ignition system for starting. > Batteries need maintenance, capacitors would > be relatively maintenance free. Also, the diode > is more robust than a relay. > > Bob . . . > ________________________________________________________________________________
Date: Sep 06, 2002
From: Bob Haan <bhaan(at)easystreet.com>
Subject: Re: wig wag and switches
Barry, I don't have Bob's switch info with me so don't know exactly what an S700 is; but I used to! Use 2 Double Pole Double Throw DPDT switches with center off. An example arrangement of these 2 switches mounted side by side - Raising the toggle of the switch that is on the right turns on WigWagging - connects the violet #22 wire to ground Raising the toggle of the switch that is on the left turns on both leading edge lights - connects the blue and green #22 wire (one to each pole) to ground Lowering the toggle of the switch that is on the right turns on the right leading edge light often called and aimed for the landing light- connects green #22 wire to ground. Lowering the toggle of the switch that is on the left turns on the left leading edge light often called and aimed for the taxi light- connects the blue #22 wire to ground. Note The WigWag switch, the violet wire connected to ground, is over ridden by either the green, blue wires connected to ground. For example, if the right switch is up for WigWag and the left switch is raised for both, both lights will turn on steady. If the right switch is up for WigWag and, if the left switch is toggled down for the left taxi light, the taxi light will be steady 100% on and the right leading edge light will be flashing on and off often called winking. Bob PS Saw an installation that used a rotary switch with positions labeled off, taxi, both, WigWag, off. Looked and worked great. Very easy to do. > >Keeping with the Lectric Bob idea of keep it simple, I want to use as >few switches as I can. > >Circumstances: > >1. Two landing lights are installed. One of them aimed slightly down >from the other, for different landing attitudes, but more importantly, >to be used as a taxi light. > >2. Bob Haan wigwag unit to be used on both lights during approach. > >3. Just before landing, wig wag off. Both landing lights on. > >4. Taxi with the one landing light (the one pointed down a little). > >First, is this a proper procedure? > >Second, How can I accomplish this with the fewest number of Bob's S700 >switches? > >Barry Pote RV9a finishing RV6A almost http://easystreet.com/~bhaan/ ________________________________________________________________________________
Date: Sep 06, 2002
From: RSwanson <rswan19(at)comcast.net>
Subject: Re: Dual, parallel batteries and chargers
I humbly beg to differ. I left my battery maintainer on my RG battery for over a month before I read what Bob said about not needing it and the voltage was never over 12.8 volts. Roger ----- Original Message ----- From: "Dennis O'Connor" <doconnor(at)chartermi.net> Subject: Re: AeroElectric-List: Re: Dual, parallel batteries and chargers > > The vast majority of "trickle chargers", even the so called regulated > chargers, overcharge the battery (actually, they hold it at too high a > voltage) and cause out gassing and loss of electrolyte... The typical 1 amp > trickle charger will boil a battery dry if left unattended for long periods, > and especially a small battery with thin plates as are used for aircraft... > Better chargers designed to be left running 24/7 that limit the trickle > voltage and current below the level of gassing, i.e. below 14 volts, can be > found at RV dealers, etc., but tend to be expensive, because quality costs > money... > However, you can inexpensively fix up your own charger with just a bit of > effort... Buy a cheap, unregulated, 1 amp charger at the auto store, or > farm store, etc.. These are usually in the $20 range... Leave it charging > the battery for a day, just so that you are sure the battery is fully > charged... Then use your volt meter to measure the DC voltage across the > battery terminals with the charger turned on... It will be considerably > above 14 volts... > The idea is to reduce the 120 vac input to the charger to the point that the > battery charger output is floating in the 13.0 - 13.5 volts DC range... Get > a light dimmer, plug the charger into it and adjust the dimmer until the > charger output voltage is where you want it (while it is attached to the > battery)... Be aware that the battery will act like a reservoir/capacitor, > so that the voltage at the battery terminals will not change rapidly with > small adjustments of the dimmer... Be patient... Make an adjustment and > leave it for an hour and recheck, etc... > This will not work with regulated trickle chargers as lowering the input > voltage will cause them to malfunction... > > Another method to lower the line voltage would be a light bulb socket wired > in series with the charger input... Try different wattage bulbs in it to > change the voltage... > > Cheers ... Denny ________________________________________________________________________________
From: BAKEROCB(at)aol.com
Date: Sep 06, 2002
Subject: better screws
<http://www.phillips-screw.com/ http://www.phillips-screw.com/mortorq.htm Check out the sites above. The have various styles including the new aerospace MORTORQ. Steve >> 9/6/2002 Thanks for your input Steve. Now can you find someone to build something other than the standard Phillips drive screws (such as MORTORQ) in 100 degree countersink flat head in stainless steel in saleable quantities less than 100,000 screw lot size at big costs? That is the real problem. We know that these things exist or can be made to exist, but the economics are just not there for us individual builders. I know that other people have pooh-poohed the problem and said that it can be easily solved. I say fine, step up to the plate and solve it. Only John Fleisher at Micro Fasteners has tried to help us to date. 'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - ?/?/? ________________________________________________________________________________
Date: Sep 07, 2002
Subject: Re: Fw: Re: Ignition System input voltage?
From: czechsix(at)juno.com
Guys, I wrote Klaus Savier to inquire about the starting problems some have reported using his Lightspeed ignition system yesterday and here is his prompt response. I'd suggest humbly that if you have the Lightspeed system and it's giving you any trouble to take it up with Klaus first before too much speculation and "fixes" get underway....if he is for some reason unable or unwilling to help resolve it, then the internet forums can be used to further troubleshoot.... I'm copying this to the RV-List since it is of interest to many RV'er's even though the discussion that prompted my questions to Klaus were on the Aeroelectric-List. --Mark Navratil Cedar Rapids, Iowa RV-8A N2D finishing.... ----- Forwarded Message ----- From: Klaus Savier <klaus(at)lightspeedengineering.com> Date: Fri, 06 Sep 2002 20:02:53 -0700 Subject: Re: Ignition System input voltage? Mark, Funny I am not aware of any problems out there. It would be best to call me if anyone has problems! The system needs to see 8v to start, once it makes sparks the voltage can drop as low as 4 v. There is a very large capacitor and filtering to accommodate the large voltage swings from the high current drain starters, so that these don't cause any problems. Even if the voltages swing rapidly the timing is stable at TDC down to 4v during the start. If the instructions are ignored and the power is taken from the buss, the relay starts to release from the low voltage, It can cause a momentary disconnect. Then all bets are off! Usually if the engine kicks back during start it is due to false triggering. This is caused by routing the high voltage coil wires too close to, or with, the input wires. Often the RG 58 cables, which carry 350v, are routed trough the same hole in the firewall as the sensor wires. This is a NO NO that the Manual warns about. Routing the input wires with the starter or alternator wire can also cause problems. Sensor wires can be routed together but should always be kept an inch or so away from high energy lines. It is easy to test for false triggering: Disconnect the high tension leads from the spark plugs and let the terminal arc to ground. Do not remove the plugs so they can provide the load for the starter. Then hook up a strobe light and check the propeller disc for a flash in the wrong place while cranking. If any inappropriate flash is observed after the above issues are addressed: Call Light Speed Engineering 805 933 3299! Klaus Savier ________________________________________________________________________________
From: "Wayne Sweet" <wsweet(at)attbi.com>
Subject: Re: Fw: Re: Ignition System input voltage?
Date: Sep 07, 2002
I also find starting problems with LSE CDI a puzzle. I had absolutely NO problems; in fact it started VERY easily with ONLY the CDI used to start. I suggest that perhaps the installation was not correct. As I stated previously, but perhaps not on this group, during mag checks, the grounding the mag didn't result in ANY RPM drop, but turning off the CDI resulted in a 120 RPM drop. In other words, the engine was being fired mainly but the CDI and the mag was "tagging along". Wayne ----- Original Message ----- From: <czechsix(at)juno.com> Subject: AeroElectric-List: Fw: Re: Ignition System input voltage? > > Guys, I wrote Klaus Savier to inquire about the starting problems some > have reported using his Lightspeed ignition system yesterday and here is > his prompt response. I'd suggest humbly that if you have the Lightspeed > system and it's giving you any trouble to take it up with Klaus first > before too much speculation and "fixes" get underway....if he is for some > reason unable or unwilling to help resolve it, then the internet forums > can be used to further troubleshoot.... > > I'm copying this to the RV-List since it is of interest to many RV'er's > even though the discussion that prompted my questions to Klaus were on > the Aeroelectric-List. > > --Mark Navratil > Cedar Rapids, Iowa > RV-8A N2D finishing.... > > ----- Forwarded Message ----- > From: Klaus Savier <klaus(at)lightspeedengineering.com> > To: czechsix(at)juno.com > Date: Fri, 06 Sep 2002 20:02:53 -0700 > Subject: Re: Ignition System input voltage? > > Mark, > Funny I am not aware of any problems out there. It would be best to call > me if anyone has problems! > The system needs to see 8v to start, once it makes sparks the voltage can > drop as low as 4 v. > There is a very large capacitor and filtering to accommodate the large > voltage swings from the high current drain starters, so that these don't > cause any problems. Even if the voltages swing rapidly the timing is > stable at TDC down to 4v during the start. > If the instructions are ignored and the power is taken from the buss, the > relay starts to release from the low voltage, It can cause a momentary > disconnect. > Then all bets are off! > Usually if the engine kicks back during start it is due to false > triggering. This is caused by routing the high voltage coil wires too > close to, or with, the input wires. Often the RG 58 cables, which carry > 350v, are routed trough the same hole in the firewall as the sensor > wires. This is a NO NO that the Manual warns about. Routing the input > wires with the starter or alternator wire can also cause problems. Sensor > wires can be routed together but should always be kept an inch or so away > from high energy lines. > It is easy to test for false triggering: Disconnect the high tension > leads from the spark plugs and let the terminal arc to ground. Do not > remove the plugs so they can provide the load for the starter. Then hook > up a strobe light and check the propeller disc for a flash in the wrong > place while cranking. > If any inappropriate flash is observed after the above issues are > addressed: Call Light Speed Engineering 805 933 3299! > Klaus Savier > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Ken Brooks" <kdbrv8r(at)charter.net>
Subject: DC Power Supplies
Date: Sep 07, 2002
A quick Yahoo search for alternatives to the out of stock Samlex power supply from Radio Shack offered several other sources. This amateur radio supply company has many listed, including two Samlex models. http://www.universal-radio.com/catalog/hamps.html I ordered the Samlex SEC-1223. It came to just under $95 with shipping and should be plenty for bench power. I'm getting ready to dive into panel wiring on my RV-8. Thanks again to Bob and this site. They give a novice like me confidence that I can really do this. Planning dual alt/single batt all-electric panel with B&C light weight starter, L40 and SD-20 alternators and 25 ah RG battery. I'm also using an Aerosport Power 180hp 0-360 with AP fuel injection and one mag/one Lightspeed EI. Firewall mounted battery and swinging either a 3-blade MT or Aerocomposites prop. Ken Brooks Roscoe, IL ________________________________________________________________________________
Date: Sep 07, 2002
From: "Jim Pack" <jpack(at)igs3.com>
Subject: Lighted Rocker Switches
Does anyone use Rocker Switches that are lighted in one position? Is it customary to light them in the "on" or "off" position? - Jim ________________________________________________________________________________
From: "jackie b johnson" <zjohnson(at)ucnsb.net>
Subject: Re: Lighted Rocker Switches
Date: Sep 07, 2002
I used 3 or 4 and they are lighted in On position..would be a little hard on battery if lighted in Off position..next start would be slow.. Jackie N5JZ -----Original Message----- From: Jim Pack <jpack(at)igs3.com> Date: September 7, 2002 9:09 AM Subject: AeroElectric-List: Lighted Rocker Switches > >Does anyone use Rocker Switches that are lighted in one position? Is it >customary to light them in the "on" or "off" position? > >- Jim > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: <nauga(at)brick.net>
Subject: Turn coordinator noise in comm
Date: Sep 07, 2002
I finally got my shiny new Microair 760 installed in my panel, and now I've got a *heck* of a howl coming from my turn coordinator. I've tried moving grounds and adding filters, but neither worked (the filter helped a little, but not enough). While messing around last night I found that if I touch both ends of a short loop of wire to the TC connector barrel (the male part attached to the TC case), the whine disappears almost completely. Can someone explain why this might make a difference? Does this point to some other problem/fix, or should I just make up a wire loop with *big* lugs and fit it to the TC? OBTW, I got *fantastic* service from Bob Nuckolls when I ordered the radio. Thanks, Dave Hyde nauga(at)brick.net RV-4 FWF and electrical ________________________________________________________________________________
Date: Sep 07, 2002
From: "Jim Pack" <jpack(at)igs3.com>
Subject: 2 1/4 Instruments (AI & DG)
Does anyone know where I can find a used (read inexpensive) electric 2 1/4" Attitude Indicator (AI) and directional gyro (DG)? Any recommendations as to Make or Model #'s? - Jim jpack(at)igs3.com ________________________________________________________________________________
From: "Cy Galley" <cgalley(at)qcbc.org>
Subject: Re: 2 1/4 Instruments (AI & DG)
Date: Sep 07, 2002
I haven't looked lately but any 2.25 AI, DG, Airspeeds, or Altimeters are very expensive because they just don't make that many. ----- Original Message ----- From: "Jim Pack" <jpack(at)igs3.com> Subject: AeroElectric-List: 2 1/4 Instruments (AI & DG) > > Does anyone know where I can find a used (read inexpensive) electric 2 > 1/4" Attitude Indicator (AI) and directional gyro (DG)? Any > recommendations as to Make or Model #'s? > > - Jim > jpack(at)igs3.com > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
Date: Sep 07, 2002
From: richard(at)riley.net
Subject: Re: 2 1/4 Instruments (AI & DG)
I've been looking, I want them to back up a Blue Mountain EFIS.. The AI's are expensive, even used and non-rebuilt. The cheapest I've ever seen is an ebay auction at $800, with no guarantee. Figure more like $1500-2000 for a rebuilt one. I've never seen a 2.25" DG, either electric or vacuum. I've ended up with a beautiful 2.25" alt, made to be certified to 50k', out of an F-18, but the rebuild on it was $800 and that was without replacing the pivots, so it's only certified to 20k. The full rebuild and cert would have been $2600. > >I haven't looked lately but any 2.25 AI, DG, Airspeeds, or Altimeters are >very expensive because they just don't make that many. >----- Original Message ----- >From: "Jim Pack" <jpack(at)igs3.com> >To: >Subject: AeroElectric-List: 2 1/4 Instruments (AI & DG) > > > > > > Does anyone know where I can find a used (read inexpensive) electric 2 > > 1/4" Attitude Indicator (AI) and directional gyro (DG)? Any > > recommendations as to Make or Model #'s? > > > > - Jim > > jpack(at)igs3.com > > > > >http://www.matronics.com/browselist/aeroelectric-list > > > > > > ________________________________________________________________________________
Date: Sep 07, 2002
From: Charlie and Tupper England <cengland(at)netdoor.com>
Subject: Re: DC Power Supplies
Ken Brooks wrote: > > > A quick Yahoo search for alternatives to the out of stock Samlex power > supply from Radio Shack offered several other sources. This amateur > radio supply company has many listed, including two Samlex models. > > http://www.universal-radio.com/catalog/hamps.html > > I ordered the Samlex SEC-1223. It came to just under $95 with shipping > and should be plenty for bench power. I'm getting ready to dive into > panel wiring on my RV-8. Thanks again to Bob and this site. They give > a novice like me confidence that I can really do this. Planning dual > alt/single batt all-electric panel with B&C light weight starter, L40 > and SD-20 alternators and 25 ah RG battery. I'm also using an Aerosport > Power 180hp 0-360 with AP fuel injection and one mag/one Lightspeed EI. > Firewall mounted battery and swinging either a 3-blade MT or > Aerocomposites prop. > > Ken Brooks > Roscoe, IL > I'm sure that the supply listed is a high quality supply. But... One of the writers for a big computer magazine used to say, "Better is the enemy of good enough." One of the little jump-start packs from Harbor Freight & similar marketers can be bought for under $40. They come with a 17 AH RG type battery, a dc charger cable and a built-in AC charger. If you consider how most of us will use a bench supply for powering an airplane's panel, It's very unlikely you would ever run the battery down during one building session and the gadget can be used for other things as well, even an emergency light if you have a power failure in your shop. You can also use it to jump start your old wet cell battery equipped vehicles. Charlie ________________________________________________________________________________
Date: Sep 07, 2002
From: Freddie Freeloader <lists(at)stevet.net>
Subject: Re: Fw: Re: Ignition System input voltage?
Hello Wayne, Saturday, September 7, 2002, 3:07:46 AM, you wrote: WS> I also find starting problems with LSE CDI a puzzle. I had absolutely NO WS> problems; in fact it started VERY easily with ONLY the CDI used to start. I WS> suggest that perhaps the installation was not correct. As I stated WS> previously, but perhaps not on this group, during mag checks, the grounding WS> the mag didn't result in ANY RPM drop, but turning off the CDI resulted in a WS> 120 RPM drop. In other words, the engine was being fired mainly but the CDI WS> and the mag was "tagging along". WS> Wayne As I recall, the original complaint was with a Jeff Rose system, not LSE. -- Best regards, Freddie mailto:lists(at)stevet.net ________________________________________________________________________________
From: "Gary Casey" <glcasey(at)adelphia.net>
Subject: "mag" drop with electronic ignition
Date: Sep 08, 2002
<> I think it is more likely that the electronic system is running at more spark advance than the mag under run-up conditions. The mag is still firing the mixture on its side of the cylinder, but later in the cycle and that's why it seems that the EI is doing all the work. Gary Casey ________________________________________________________________________________
Date: Sep 08, 2002
From: "Paul A. Franz, P.E." <paul(at)eucleides.com>
Subject: Re: DC Power Supplies
At 08:57 AM 9/7/2002Charlie and Tupper England sez: >One of the writers for a big computer magazine used to say, >"Better is the enemy of good enough." One of the little >jump-start packs from Harbor Freight & similar marketers can >be bought for under $40. They come with a 17 AH RG type >battery, a dc charger cable and a built-in AC charger. $40 includes the 17 AH RG battery? For that money I'd use the battery in my airplane. You have a real source that cheap? How about a URL or phone number? Paul Franz PAF Consulting Engineers | 427 - 140th Ave NE (425)641-8202 voice | Bellevue, WA 98005 (425)641-1773 fax | <http://blackdog.bellevue.wa.us/> ________________________________________________________________________________
Date: Sep 08, 2002
From: Charlie and Tupper England <cengland(at)netdoor.com>
Subject: Re: DC Power Supplies
"Paul A. Franz, P.E." wrote: > > > At 08:57 AM 9/7/2002Charlie and Tupper England sez: > >One of the writers for a big computer magazine used to say, > >"Better is the enemy of good enough." One of the little > >jump-start packs from Harbor Freight & similar marketers can > >be bought for under $40. They come with a 17 AH RG type > >battery, a dc charger cable and a built-in AC charger. > > $40 includes the 17 AH RG battery? For that money I'd use the battery in my > airplane. > > You have a real source that cheap? How about a URL or phone number? > > Paul Franz > > PAF Consulting Engineers | 427 - 140th Ave NE > (425)641-8202 voice | Bellevue, WA 98005 > (425)641-1773 fax | > <http://blackdog.bellevue.wa.us/> > http://www.harborfreight.com/cpi/ctaf/displayitem.taf?function=Search This item is in their current retail store snail mail flyer for $39.99; it goes on sale about every 2-3 months. I don't know whether they will honor the price if mail ordered. Be aware that for a/c use, the battery in this device *might* not be of the same quality as the higher priced batteries. Mine doesn't have a brand label, if my memory is working. However, if I were using a conventional a/c engine with mag ignition, I wouldn't hesitate to use it in the plane. Charlie Charlie ________________________________________________________________________________
From: ScramIt(at)aol.com
Date: Sep 08, 2002
Subject: Digitrak Rev 2
I was checking web sites when I happened to see this: GPS NAV MODE ADDED TO DIGITRAK =A0 In addition to flying drift-free selected direction without having to program the GPS, a GPS NAV MODE has been added. This mode is superior to systems which track the CDI. It can fly to, intercept, and track a programmed route from any position. Once on course, heading does not fluctuate as is generally the case with conventional NAV couplers. In fact, this new digitally computed NAV MODE approaches the capability of GPS steering. GPS steering is a series of bank commands sent to an autopilot by a GPS, which computes the path to be followed. For those who purchased the initial version of the DIGITRAK, the new NAV MODE can be added for $150.00 after October 1. So I'm not sure what the digitrak does now. They give a good explanation of what it doesn't do. I.E. GPS steering. The manuals make no mention of this feature. I have unit 12 so it looks like an upgrade for me. If it can do what the first line of the add says that's good enough for me. (haha! I didn't mention track or heading once! : ) SteveD A217 http://homepage.mac.com/sdunsmuir/Europa.html ________________________________________________________________________________
From: Garfield Willis <garwillis(at)msn.com>
Subject: Re: "mag" drop with electronic ignition
Date: Sep 08, 2002
wrote: ><previously, but perhaps not on this group, during mag checks, the grounding >the mag didn't result in ANY RPM drop, but turning off the CDI resulted in a >120 RPM drop. In other words, the engine was being fired mainly but the CDI >and the mag was "tagging along".>> > >I think it is more likely that the electronic system is running at more >spark advance than the mag under run-up conditions. The mag is still firing >the mixture on its side of the cylinder, but later in the cycle and that's >why it seems that the EI is doing all the work. That's a theory, but if true that the mag is still "doing some of the work" by firing later, then you'd expect to also see at least some RPM drop if the mag were disconnected. And that doesn't seem to be the case. Gar ________________________________________________________________________________
From: Garfield Willis <garwillis(at)msn.com>
Subject: Re: "mag" drop with electronic ignition
Date: Sep 08, 2002
wrote: >wrote: > >>I think it is more likely that the electronic system is running at more >>spark advance than the mag under run-up conditions. >That's a theory, but if true that the mag is still "doing some of the >work" by firing later, then you'd expect to also see at least some RPM >drop if the mag were disconnected. And that doesn't seem to be the case. Only moments after hitting the send button, it dawned on me I'd completely missed the point you were trying to make. I gather the point you WERE trying to make was that, to fairly compare the difference between EI and Mag due to spark quality alone, you'd want to make sure they were both firing with the same advance, before you did the RPM drop mag check. My apologies for my myopia. Gar ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)tenforward.com>
Subject: Re: DC Power Supplies
Date: Sep 08, 2002
On sale (39.99) locally to you at retail store. Lot # 38391. stores in Everett, Lacey and Tacoma. Everett #425-513-6213. Named "12VOLT JUMP-START SYSTEM AND POWER SUPPLY" Not sure if on sale mail order. Normal price is 59.99 I have had one for several months and it seems to do the job as advertiesed. Paul ----- Original Message ----- From: "Paul A. Franz, P.E." <paul(at)eucleides.com> Subject: Re: AeroElectric-List: DC Power Supplies > > At 08:57 AM 9/7/2002Charlie and Tupper England sez: > >One of the writers for a big computer magazine used to say, > >"Better is the enemy of good enough." One of the little > >jump-start packs from Harbor Freight & similar marketers can > >be bought for under $40. They come with a 17 AH RG type > >battery, a dc charger cable and a built-in AC charger. > > $40 includes the 17 AH RG battery? For that money I'd use the battery in my > airplane. > > You have a real source that cheap? How about a URL or phone number? > > > Paul Franz > > PAF Consulting Engineers | 427 - 140th Ave NE > (425)641-8202 voice | Bellevue, WA 98005 > (425)641-1773 fax | > <http://blackdog.bellevue.wa.us/> > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
Date: Sep 08, 2002
From: "Boyd C. Braem" <bcbraem(at)comcast.net>
Subject: Re: "mag" drop with electronic ignition
The EI IS doing all the work! In my airplane (with a '98 LSE EI), with the EI on, performance data from Vx, Vy and top speed are completely unaffected as to the Bendix mag being on or off. RPM drop during run-up is -200 rpm. After mag "rebuild" at 400 hrs, there's no change in performance data. Performance with the single mag, alone, is Horrible--it's like I have a 160 hp -360 or something. Boyd. RV-Super 6 Garfield Willis wrote: > > wrote: > > >< >previously, but perhaps not on this group, during mag checks, the grounding > >the mag didn't result in ANY RPM drop, but turning off the CDI resulted in a > >120 RPM drop. In other words, the engine was being fired mainly but the CDI > >and the mag was "tagging along".>> > > > >I think it is more likely that the electronic system is running at more > >spark advance than the mag under run-up conditions. The mag is still firing > >the mixture on its side of the cylinder, but later in the cycle and that's > >why it seems that the EI is doing all the work. > > That's a theory, but if true that the mag is still "doing some of the > work" by firing later, then you'd expect to also see at least some RPM > drop if the mag were disconnected. And that doesn't seem to be the case. > > Gar ________________________________________________________________________________
From: "Gabe and Marisol Ferrer" <ferrergm(at)bellsouth.net>
Subject: Coax Cable Stripping
Date: Sep 08, 2002
Anyone have a good method for removing the insulation from coax cable? I've been using a exacto knife to reach the bare wire. In order to install the crimp pin. Can't always get it right on the first try. Thanks in advance. Gabe A Ferrer (RV6) SE Florida ferrergm(at)bellsouth.net Cell: 561 758 8894 Night or FAX: 561 622 0960 ________________________________________________________________________________
From: "Tom Barnes" <skytop(at)megsinet.net>
Subject: Re: Coax Cable Stripping
Date: Sep 08, 2002
I have used with success the heavy guage wire cutter that Bob sells (the one used for cutting battery cables). Work the cable back and forth clockwise, then ccw while slowly clamping down the jaws. Get to within a few thousands and then finish it off with the exacto knive. For the outside shield exposure, I barely cut the surface (360 degrees) with the cutter, then bend it at a sharp angle and the outter shell usually breaks and exposes the shield. Tom Barnes -6 ----- Original Message ----- From: "Gabe and Marisol Ferrer" <ferrergm(at)bellsouth.net> Subject: AeroElectric-List: Coax Cable Stripping > > Anyone have a good method for removing the insulation from coax cable? > > I've been using a exacto knife to reach the bare wire. In order to install > the crimp pin. > > Can't always get it right on the first try. > > Thanks in advance. > > Gabe A Ferrer (RV6) > SE Florida > ferrergm(at)bellsouth.net > Cell: 561 758 8894 > Night or FAX: 561 622 0960 > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Alex Peterson" <alexpeterson(at)usjet.net>
Subject: Coax Cable Stripping
Date: Sep 08, 2002
> Anyone have a good method for removing the insulation from coax cable? I used a single edge razor blade and carefully cut through to the proper depth. Alex Peterson Maple Grove, MN RV6-A N66AP 200 hours ________________________________________________________________________________
Date: Sep 08, 2002
From: richard(at)riley.net
Subject: Coax Cable Stripping
> > > > Anyone have a good method for removing the insulation from coax cable? I got a stripping tool from http://www.ecwest.com/shopping/PriceList.asp?sType=68 part number RFA-4086-003. It was $45 but I'm tired of living with bad tools. Strips RG58, ML900, RG142, RG400, RG59 ________________________________________________________________________________
From: Carl Coulter <coulter(at)gci.net>
Date: Sep 08, 2002
Subject: Aerocomposites prop?
> From: "Ken Brooks" <kdbrv8r(at)charter.net> (snip)3-blade MT or > Aerocomposites prop.(snip) Ken - Who makes Aerocomposites props/ I could not find any mention of them on the web. carl (GS with an angle valve IO-360) ________________________________________________________________________________
Date: Sep 08, 2002
From: richard(at)riley.net
Subject: Re: Aerocomposites prop?
>Ken - Who makes Aerocomposites props/ I could not find any mention of >them on the web. Did you try http://www.aerocomposites.com ? ________________________________________________________________________________
From: "usinet.willfly" <willfly(at)attglobal.net>
Subject: Magnetos and Electronic Ignition
Date: Sep 09, 2002
I just hung my XP 0360 engine and am going to start the finish wiring soon. I am set up with a left magneto for the bottom cylinders and a lightspeed EI for the top cylinders. How do I tell if there is an impulse coupler on the left magneto? If there is, should I turn the L MAG on for engine start? If there is ,could I alternate EI for start one time and the next start on L MAG? Could a procedure like this serve as a test for the L MAG? Does anyone have a good source of information on wiring with one EI and one MAG? Steve Glasgow ... ! ... \............O............/ ________________________________________________________________________________
From: "Dave Ford" <dford(at)michweb.net>
Subject: power supply location
Date: Sep 09, 2002
I have a single unit Whelen power supply for strobes that I want to locate under the pilot seat aft. Is this a suitable location or will this be a source of noise for antennae, intercom, etc. Dave Ford RV6 ________________________________________________________________________________
From: "Ken Brooks" <kdbrv8r(at)charter.net>
Subject: Aerocomposites Prop
Date: Sep 09, 2002
Carl Coulter asked -- snipsnip http://www.aerocomposites.com/html/index.html I spoke with John Violette at OSH and was very impressed by his design of this prop. It is so thin in cross-section it's amazing. They are flight testing in on an RV-8, among others, and since I don't need a prop until Fall of 03, I have the luxury of waiting for test results, etc. Might be worth the extra money to some. Ken Brooks Roscoe, IL RV-8 Panel and wiring ________________________________________________________________________________
Date: Sep 09, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: RE: Brownout" during cranking...
> > >I have a Lightspeed EI and a mag without an impulse coupling, so I always >start on the EI. I also have separate toggle switches for each ignition >system and a push button starter. My starting procedure is to press and >hold the starter button then switch on the EI. At 75 hours I have >experienced no kick back or starting problems. The battery is still >relatively fresh, so problems could show up later when the battery starts >showing some age. This is a good data point that perhaps only demonstrates that one can expect a higher average battery voltage AFTER the starter motor is running and its inrush current event has passed. Take care, however, lest we infer that this is either necessary or even just-a-good-thing-to-do with respect to the operation of the ignition system. It's data points like this that once filtered through the ol' "gossip on the telephone" game that take on status of sage advice. As I've suggested many times in the past on this and other topics with respect to component operations on airplanes. Let's work to understand if and why any component should require extraordinary care in its use -AND- then be good consumers and badger the socks off of suppliers that are not doing a good job. I don't care how well any given product performs in cruising flight if it takes extra-ordinary attention from the pilot just to get it going -OR- to avoid errant behavior that risks any kind of damage. Bob . . . ________________________________________________________________________________
Date: Sep 09, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Electronic Ignition
> >For those of you that have 1 Mag / 1 Electronic Ignition, When >preparing to start, do you turn on the Alt/Bat before or after you turn >on the mag & EI? Or does it matter? Shouldn't matter. Bob . . . ________________________________________________________________________________
Date: Sep 09, 2002
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: power supply location
> >I have a single unit Whelen power supply for strobes that I want to >locate under the pilot seat aft. Is this a suitable location or will >this be a source of noise for antennae, intercom, etc. > >Dave Ford >RV6 Shouldn't be a problem. Bob . . . ________________________________________________________________________________
From: "Shannon Knoepflein" <kycshann(at)kyol.net>
Subject: Aerocomposites Prop
Date: Sep 09, 2002
The AeroComposites 3 blade on an IO-550 in a Lancair Legacy showed a 1000fpm increase in climb, and several knots in cruise, over a hartzell 2 blade. The tests were done on the same day, same plane, same condtions, only thing different was the prop. The AeroComposites was hands down the winner in every regard. I can get the more exact details if anyone is interested. --- Shannon Knoepflein <---> kycshann(at)kyol.net -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Ken Brooks


August 25, 2002 - September 09, 2002

AeroElectric-Archive.digest.vol-bc