AeroElectric-Archive.digest.vol-hv

May 12, 2008 - May 26, 2008



      
________________________________________________________________________________
Subject: Use of 700-2-10 switch for Voltage Sense - how to wire?
From: "mikef" <mikefapex(at)gmail.com>
Date: May 12, 2008
I am building a Z-19 type electrical system and I have a question about a switch configuration. I was planning to use a 2-10 / three position to view voltage on different buses, depending on the position: 1. E Bus voltage 2. Main Battery Bus voltage 3. Engine Battery Bus voltage I have a digital volt meter with simple +/- inputs. First, do you think this switch 2-10 will work or should I use something else? I've played around with various wire combinations and a 2-10 switch but have come up short (not a short, ha!). I just cannot seem to figure out the right combination that provides the power feed to a single switch position/combination. So that is the crux of my problem, the right wiring for this switch (if possible). I know that all three PLUS leads from the bus to switch to meter need to be isolated through the switch. I seem to get one source isolated but then another switch position lights up two power leads. The ground is common across all buses and batteries. 2-10 switch layout KEYWAY UP 3 6 2 5 1 4 Thanks for any wiring suggestions, Mike Read this topic online here: http://forums.matronics.com/viewtopic.php?p=182750#182750 ________________________________________________________________________________
Date: May 12, 2008
From: Joe Dubner <jdubner(at)yahoo.com>
Subject: Re: GPS antennas with miniature connector
On 05/12/2008 09:14 Carlos Trigo wrote: > > Can somebody else please indicate me a way of getting rid of those 2 useless > coils of GPS antenna cable? Carlos, I had a similar dilemma a few years ago and decided to retain the connector rather than install a new one. I cut the cable near the connector, cut the antenna end of the cable to the desired length, and spliced the two pieces of the cable back together. This is also a viable technique if you need to "temporarily" remove the connector for cable routing through a small conduit or to lengthen the cable. The pundits will tell you that you can't splice this coax as it carries a very weak 1.575 GHz signal but I never noticed any degradation in the performance of the GPS. Of course, I paid attention to detail in the splice by keeping the splice length to a minimum, re-insulating the center conductor well, and then restoring the shield coverage to as near 100% as possible. Best, Joe Long-EZ 821RP Lewiston, ID ________________________________________________________________________________
Date: May 12, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: GPS antennas with miniature connector
>Listers > >I have 2 GPS antennas to install, one is for my Trutrak ADI and the other >for the GRT - EFIS, both having internal GPS. >I attached 2 pictures of one of them, they are similar, both use a thin >cable (less than 1/8" outer diameter) and a miniature brass connector. > >Since we must always seek to save some weight in our birds, I have 2 >questions: > >First question, which is probably dumb, but here it goes: can I install only >one antenna and T the cable for both devices? No, for a couple of reasons. One is that this antenna . . . http://www.laipac.com/ant_GLP1_RA_eng.htm is a powered device that gets its operating voltage from the associated GPS receiver. Mixing two receivers onto a single antenna offers some system integration as well as some system reliability (single point of failure for both receivers) issues. Recommend you stick with dual antennas. >Second question: if I want to get rid of that much cable length, can I cut >it somewhere in the middle, remove the unnecessary length, and reconnect the >cable ends? If yes, how do I do it? >Or is it better to forget the existing connector, cut the necessary length >and use a new connector? In this case, where can I find these miniature >connectors and is there a special crimper for these? From the photos, I deduce that your antennas are fitted with the SMB series connectors. But these come in several styles that include screw on and push-on. It looks like you have the push-on style. http://www.aeroelectric.com/Pictures/Connectors/Coax/SMB_push-on_1.jpg http://www.aeroelectric.com/Pictures/Connectors/Coax/SMB_push-on_2.jpg http://www.aeroelectric.com/Pictures/Connectors/Coax/SMB_push-on_3.jpg Digikey sells these connectors but a quick look for tools did not produce any hits. The task of shortening these cables is trivial for anyone with the skills, tools and connectors. You may be able to find someone locally who routinely works with these connectors and get the job done. However, keep in mind that the antenna assembly's performance IS BASED on the as-supplied condition . . . meaning that it will perform as advertised with the long cables. It's doubtful that you'll improve on that performance in any way that you can perceived so this leaves you with the goal of shortening the cables because it looks better and saves a little weight. Obviously we need to leave it to you to deduce the trade-off for accepting the costs and risks for a DIY cable shortening effort and the return on investment for achieving a slicker looking installation and a few ounces of weight. My best recommendation is that (unless you can find some local support in skills/materials/tools) you leave them as supplied. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: May 12, 2008
Subject: Re: GPS antennas with miniature connector
From: simon(at)synchronousdesign.com
Matt, If his GPS antenna is powered by the receivers, then a T no doubt will interfere with that function, as DC doesn't pass through transformers. If Carlos can give us more details pertaining to the specific antenna and GPS receiver models, then his problem can be analyzed further. Joe Dubner earlier said he spliced his GPS antenna cable in the middle, and it performed well. I am surprised, but I've seen stranger stuff happen. I'd rather remove the connector, cut the cable, run it through the small opening, and reinstall a new connector. Simon Oviedo, FL USA > > > Aren't many GPS antennas active (amplified, powered)? If so, it > should be possible to design an impedance match circuit from the > output of the antenna to the input of the two receivers. It's > also possible that the output of the amplified antenna is robust > enough to not require any match circuitry for adequate > performance... > > Regards, > > Matt- ________________________________________________________________________________
Date: May 12, 2008
Subject: Re: GPS antennas with miniature connector
From: "Matt Prather" <mprather(at)spro.net>
Right.. You'd have to admit though that it wouldn't be rocket science to make 5VDC available to the antenna - from the antenna side of the matcher. Then again, I'd likely try to find antennae that's smaller/lighter, and with shorter cables.. Matt- > > Matt, > > If his GPS antenna is powered by the receivers, then a T no doubt will > interfere with that function, as DC doesn't pass through transformers. If > Carlos can give us more details pertaining to the specific antenna and GPS > receiver models, then his problem can be analyzed further. > > Joe Dubner earlier said he spliced his GPS antenna cable in the middle, > and it performed well. I am surprised, but I've seen stranger stuff > happen. I'd rather remove the connector, cut the cable, run it through > the small opening, and reinstall a new connector. > > Simon > Oviedo, FL USA > > >> >> >> Aren't many GPS antennas active (amplified, powered)? If so, it >> should be possible to design an impedance match circuit from the >> output of the antenna to the input of the two receivers. It's >> also possible that the output of the amplified antenna is robust >> enough to not require any match circuitry for adequate >> performance... >> >> Regards, >> >> Matt- > > ________________________________________________________________________________
Subject: Re: Use of 700-2-10 switch for Voltage Sense - how
to wire?
Date: May 12, 2008
From: "Glaeser, Dennis A" <dennis.glaeser(at)eds.com>
Mike, The 2-10 is an ON-ON-ON switch, which is useful as a Bat/Alt master, but not suited for your task because it provides for multiple simultaneous connections, and you only want one at a time. Z-19 shows how to connect a 1-7 switch to check the voltage of each of the batteries - any reason not to do it that way? However you do it, you need a way to leave the voltmeter disconnected, or else it is a constant drain on the battery. Dennis Glaeser RV-7A Egg H6 Subaru - flying (Phase 1) ------------------------------------------------------------------------ ------ I am building a Z-19 type electrical system and I have a question about a switch configuration. I was planning to use a 2-10 / three position to view voltage on different buses, depending on the position: 1. E Bus voltage 2. Main Battery Bus voltage 3. Engine Battery Bus voltage I have a digital volt meter with simple +/- inputs. First, do you think this switch 2-10 will work or should I use something else? I've played around with various wire combinations and a 2-10 switch but have come up short (not a short, ha!). I just cannot seem to figure out the right combination that provides the power feed to a single switch position/combination. So that is the crux of my problem, the right wiring for this switch (if possible). I know that all three PLUS leads from the bus to switch to meter need to be isolated through the switch. I seem to get one source isolated but then another switch position lights up two power leads. The ground is common across all buses and batteries. 2-10 switch layout KEYWAY UP 3 6 2 5 1 4 Thanks for any wiring suggestions, Mike ________________________________________________________________________________
Date: May 12, 2008
Subject: Re: GPS antennas with miniature connector
From: simon(at)synchronousdesign.com
Matt, I admit it is not rocket science to provide DC voltage if you have the source and delivery system for it. In Carlos' case, though, I believe his goal was to squeeze nano-tons of weight out of whatever he was doing, and an additional wire from one receiver or power supply to the antenna would defeat this purpose. He might as well stay with the extra cable length. In an earlier email, Bob said that two receivers supplying VDC will introduce further complications, and one antenna feeding two receivers is a single-failure point. These two statements are valid. If two GPS receivers were going into my airplane, I would have two separate antennas. Of course, I'm not as worried about weight as Carlos is either. I know a guy who wants to cross the Atlantic in July and August, and he's in the same "bloat." Simon Oviedo, FL USA > Right.. You'd have to admit though that it wouldn't be rocket science to > make 5VDC available to the antenna - from the antenna side of the matcher. > > Then again, I'd likely try to find antennae that's smaller/lighter, and > with shorter cables.. > > Matt- ________________________________________________________________________________
From: "Carlos Trigo" <trigo(at)mail.telepac.pt>
Subject: GPS antennas with miniature connector
Date: May 12, 2008
OK, I surrender. I will use 2 antennas and keep those lengthy cables. A 3 month diet will save weight on myself, which seems easier (apart from being better for my health). Thanks to everybody who answered. Carlos ________________________________________________________________________________
Subject: Re: Use of 700-2-10 switch for Voltage Sense - how
to wire?
From: "mikef" <mikefapex(at)gmail.com>
Date: May 12, 2008
>>Z-19 shows how to connect a 1-7 switch to check the voltage of each of the batteries - any reason not to do it that way? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=182793#182793 ________________________________________________________________________________
From: "Henry Trzeciakowski" <hammer408(at)comcast.net>
Subject: Re: EFIS Battery Back-up Power
Date: May 12, 2008
Ron: I'm using Z-11 architecture: single battery/single alternator. My e-bus is already carring about 12 amps, so the idea behind the internal battery EFIS was to wire to main bus. With that in mind, your explaination of the Alternator Failure Procedure is what I wasn't certain of and I believe you clarified and confirmed it. Alternator Failure: 1- E-bus alternate feed is turned ON which powers the e-bus directly from the battery. 2- Immediately turn the Main Battery Contactor OFF (DC Master Power Switch) - Main Bus is now off- line, main bus drops below about 12 volts and the EFIS resorts to it's internal battery. and no additional switches would be necessary. Thanks Hank ----- Original Message ----- From: Ron Shannon To: aeroelectric-list(at)matronics.com Sent: Sunday, May 11, 2008 10:42 AM Subject: Re: AeroElectric-List: Re: EFIS Battery Back-up Power Hank, If you have just one EFIS, it (or if you have two, the first one) should be wired to the e-bus -- assuming you want to have the EFIS available during endurance (battery only) flight ops -- as most of us would like to have. If you have two EFIS's, you may want to shut one down during endurance ops, and the second one would therefore be wired to the main bus. (If that second EFIS already has an automatic internal battery, you may have to shut it down manually even though it's on the main bus, to save that internal battery.) This is the way my dual AFS-3400 EFIS system is wired. The e-bus is normally fed from the main bus through a one-way diode. When the alternator(s) fail, the e-bus alternate feed is turned ON which powers the e-bus direct from the battery, i.e., not through the main battery contactor. (For brief moment, the e-bus is then effectively fed from two places: the battery upstream of the battery contactor, and the main bus, from downstream of the battery contactor.) After the e-bus alternate feed has been turned ON, you immediately turn the main battery contactor OFF, to rapidly and positively shed those non-essential main bus loads. That's the sequence (e-bus alt feed ON, then main battery contactor OFF) to keep the e-bus powered and avoid rebooting things like your EFIS that are on the e-bus when you shut down the main. When the e-bus alternate feed is ON, and the main battery contactor and main bus are OFF, the e-bus will not back feed the main bus because the diode keeps current from flowing from the e-bus to the main bus. I hope that helps explain the desired function and results. Ron On Sun, May 11, 2008 at 12:58 PM, Henry Trzeciakowski wrote: Bob: I'm planning to install a AFS 3400 with it's own internal battery back-up...... fused it to my Main Bus.. How I visualize: main alternator goes off line, I kill the alternator via the master switch, turn on the E-Bus alternator feed switch.... Since the Main Bus will be de-energized due to a failed alternator, I assume that the EFIS will utilize it's internal battery to keep the EFIS energized..... OR is my thought process all wrong !!! Do I need a seperate switch on my panel to turn the EFIS off, eventhough the Main Bus is de-energized.... What would the wiring architect be in this case ?? Thanks Hank ________________________________________________________________________________
From: Fiveonepw(at)aol.com
Date: May 12, 2008
Subject: Re: GPS antennas with miniature connector
In a message dated 05/12/2008 12:18:32 PM Central Daylight Time, simon(at)synchronousdesign.com writes: > Second question: if I want to get rid of that much cable length, >>> I recently installed a Garmin 430W (WAAS) that has a dedicated GPS antenna with a "required" MINIMUM cable length of something like 18 FEET. Being a "certified" navcom, I kinda surmised that Garmin requires this because they have to make sure there is sufficient signal strength getting to the receiver. Huh? Picture a 430W installed in a King Air with the antenna halfway aft on the top of the fuse- might take 30-40' of cable to connect the two. Using the same certified antenna for all certified installations, how does a manufacturer offer a unit that ALSO works in Katanas? By making sure the signal strength is sufficient for either installation, hence the minumum/maximum cable length for which the unit is guaranteed it will work. Really wanting to avoid wadding up an extra 15 feet of RG400, I called Garmin tech and they confirmed my theory. If I had shortened the cable to a convenient minimun length (about 3") the signal would have been too powerful for the receiver due to insufficient attenuation. OK, but how about shortening the cable and adding an attenuator, being on an experimental. The guy basically said fine, but you're on your own! After a couple of hours researching this option and coming up with no simple answers, I decided the path of least resistance was to do as instructed. I wadded up the extra 15 feet of RG400, and the sucker works just great. Still got a warranty, too! Win-win! I'd guess you have the same situation with the smaller GPS antennas(ae?) and that is why they come with all that extra cable. Just wad it up (like I did for the GRT & ADI GPS & XM cables) and be glad it ain't RG400! Mark **************Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. (http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001) ________________________________________________________________________________
Date: May 12, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Use of 700-2-10 switch for Voltage Sense - how
to wire? > >I am building a Z-19 type electrical system and I have a question >about a switch configuration. I was planning to use a 2-10 / three >position to view voltage on different buses, depending > on the position: > > 1. E Bus voltage > 2. Main Battery Bus voltage > 3. Engine Battery Bus voltage > >I have a digital volt meter with simple +/- inputs. > > First, do you think this switch 2-10 will work or should I use > something else? > > I've played around with various wire combinations and a 2-10 switch but > have come up short (not a short, ha!). I just cannot seem to figure out > the right combination that provides the power feed to a single switch > position/combination. So that is the crux of my problem, the right wiring > for this switch (if possible). I know that all three PLUS leads from the > bus to switch to meter need to be isolated through the switch. I seem to > get one source isolated but then another switch position lights up two > power leads. > >The ground is common across all buses and batteries. The 2-10 would work but as others have noted, leaving a voltmeter connected to a battery bus for long periods of time may present a battery service readiness issue. If you use the 2-70 architecture (spring loaded to center) you can use the center position to read e-bus (which goes down with the master switches). The extremes are used to measure batteries and cannot be inadvertently left ON after the airplane is shut down. A miniature version of the 2-70 is a C&K 7215SYZQ available from Digikey at: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=CKN1134-ND Wiring for this switch is illustrated at: http://www.aeroelectric.com/Pictures/Schematics/3-Ch_Voltmeter.pdf Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
From: "r falstad" <bobair8(at)msn.com>
Subject: 14 VDC Power Cord for Digital Video Camera?
Date: May 12, 2008
Folks, I have a new digital video camera (Canon FS-11) that I want to rig up in the cabin of my GlaStar for its test flight program. I intend to use a patch cord to connect my intercom with the "Mic In" function on the camera so I can dictate information to the video instead of having to write it down. I'd also like to power the camera from ship's power but Canon doesn't sell a "car cord" for this camera. The Canon tech rep says the camera is sensitive to its input voltage (8.4 VDC) from the output of the 110 VAC power converter. I don't want the extra wires and weight of an inverter -- I'd rather make up my own power cord to plug directly from ship's power to the camera. I can put a resistor in to drop the voltage but I'm worried about spikes and their possible adverse effects on the camera. Is there a circuit that would regulate the output close to 8.4 VDC with the expected input voltages from ship's power? (FYI, the compact power adapter is Canon P/N CA-590 and its input specs are 100 - 240 VAC at 50/60 Hz drawing 0.14 - 0.08 Amps with output at 8.4 VDC at 0.6 Amps. The tech rep wouldn't/couldn't tell me the tolerance on the input voltage to the camera.) Should I put in a smaller capacity (1 Amp) fuse instead of the 5 Amp fuse I've got in there now? Bob ________________________________________________________________________________
Date: May 12, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: SMB connnectors on small coax (RG-174 et. als.)
>>Second question: if I want to get rid of that much cable length, can I cut >>it somewhere in the middle, remove the unnecessary length, and reconnect the >>cable ends? If yes, how do I do it? >>Or is it better to forget the existing connector, cut the necessary length >>and use a new connector? In this case, where can I find these miniature >>connectors and is there a special crimper for these? I was just looking for materials and tools on another task an ran across these items that may be of interest to folks who need to re-work or fabricate cables with SMB Push-Ons. See SMB-Push-on male connectors at: http://www.jameco.com/Jameco/catalogs/c261/P143.pdf and installation tool at: http://www.jameco.com/Jameco/catalogs/c261/P279.pdf Bob . . . ________________________________________________________________________________
From: "Carl Morgan" <zk-vii(at)rvproject.gen.nz>
Subject: 14 VDC Power Cord for Digital Video Camera?
Date: May 13, 2008
Hi Bob, I've just been through this with ours, although we are a RV7A and I'm using older MV400i DV Canon tape technology. I actually made a small switched power supply board - the primary problem was finding the power cord plug, In the end I went lo-tech and used a larger battery! The battery lasts 2 hours, the tape media lasts 1.5 hours and most flight tests were less than an hour. I added a 3.5mm jack to jack which was connected to the stereo headphone lines from the Garmin 340 - although I did need to add a couple of resitors to attenuate the volume down a bit. The video recorder tended to auto-gain on the audio and struggled with over loading - but for the purposes needed it worked fine. The footage came out ok ( see http://www.youtube.com/zkvii ) and the learning aspect of reviewing your flying was much more benefical than I had expected - things like cockpit resourcing, radio calls, checks all can be critically reviewed later. Regards, Carl -- Carl Morgan - ZK-VII - RV 7A http://www.rvproject.gen.nz/ -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of r falstad Sent: 13 May 2008 15:10 To: AEROELECTRIC LIST Subject: AeroElectric-List: 14 VDC Power Cord for Digital Video Camera? Folks, I have a new digital video camera (Canon FS-11) that I want to rig up in the cabin of my GlaStar for its test flight program. I intend to use a patch cord to connect my intercom with the "Mic In" function on the camera so I can dictate information to the video instead of having to write it down. I'd also like to power the camera from ship's power but Canon doesn't sell a "car cord" for this camera. The Canon tech rep says the camera is sensitive to its input voltage (8.4 VDC) from the output of the 110 VAC power converter. I don't want the extra wires and weight of an inverter -- I'd rather make up my own power cord to plug directly from ship's power to the camera. I can put a resistor in to drop the voltage but I'm worried about spikes and their possible adverse effects on the camera. Is there a circuit that would regulate the output close to 8.4 VDC with the expected input voltages from ship's power? (FYI, the compact power adapter is Canon P/N CA-590 and its input specs are 100 - 240 VAC at 50/60 Hz drawing 0.14 - 0.08 Amps with output at 8.4 VDC at 0.6 Amps. The tech rep wouldn't/couldn't tell me the tolerance on the input voltage to the camera.) Should I put in a smaller capacity (1 Amp) fuse instead of the 5 Amp fuse I've got in there now? Bob Checked by AVG. 18:14 ________________________________________________________________________________
Date: May 13, 2008
From: John Morgensen <john(at)morgensen.com>
Subject: Fuse Block Locations
I am seeking pictures and advice on fuse block locations, panel ground, firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture. Thanks, John Morgensen 775 771-5791 ________________________________________________________________________________
From: "Richard Dudley" <rhdudley1(at)bellsouth.net>
Subject: Re: Fuse Block Locations
Date: May 13, 2008
Hi John, I have attached a photo of my solution to the fuse panel location. It is hinged to the bottom of the instrument panel and swings back to a horizontal position and is secured by two Camlocks. Since plan is to deal with fuses only on the ground, it is out of the way during flight. My architecture is based on Bob Nuccols Z-11. The diode connection to the e-buss is mounted on the backside of the panel. Hope this is some help. Regards, Richard Dudley -6A flying ----- Original Message ----- From: "John Morgensen" <john(at)morgensen.com> Sent: Tuesday, May 13, 2008 9:30 AM Subject: AeroElectric-List: Fuse Block Locations > > > I am seeking pictures and advice on fuse block locations, panel ground, > firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture. > > Thanks, > John Morgensen > 775 771-5791 > > > ________________________________________________________________________________
Subject: Re: Use of 700-2-10 switch for Voltage Sense - how
to wire?
From: "mikef" <mikefapex(at)gmail.com>
Date: May 13, 2008
Bob, That was the info I was looking for. Thanks very much, seems like a straightforward solution. Mike Read this topic online here: http://forums.matronics.com/viewtopic.php?p=182910#182910 ________________________________________________________________________________
From: "Joe" <fran5sew(at)banyanol.com>
Subject: Re: Use of 700-2-10 switch for Voltage Sense - how
to wire?
Date: May 13, 2008
Mike, You need a triple throw switch, either single pole or double pole, commonly known as SP3T or DP3T. You can buy them at electronic supply companies such as Digikey or Mouser or Allied. Parenthesis ( ) in the description indicates a momentary position. Avoid those unless you want that feature. You have to hold the switch in that position and when you let go, it moves to the previous position. http://www.mouser.com/search/Default.aspx has several triple-throw switches to choose from: SP3T $14.08 part number: 506-MTG206PA gold contacts SP3T $9.43 part number: 506-MTA206PA gold contacts SP3T $7.50 part number: 633-M202401-RO silver contacts SP3T $8.50 part number: 633-M202402-RO silver contacts SP3T $9.70 part number: 633-M202404-RO silver contacts DP3T $14.90 part number: 633M204401-RO silver contacts You can look at a catalog page here: http://www.mouser.com/catalog/634/1582.pdf Gold contacts have less resistance and will not corrode but they can NOT handle very much current. But they should be good for measuring voltage. Silver contacts can handle more current. The double pole switch is more versatile and can be used for other applications such as in place of the 2-10 switch in the Z drawings (if external jumpers are connected properly). You could wire the DP3T contacts in parallel and thus cut the resistance in half and make the switch more reliable. If one half of the DP3T switch develops high resistance, the other half will carry the current and you would not see a problem. The reason that the 2-10 switch would not work for you is that it has internal jumpers connecting some of the contacts. Joe ________________________________________________________________________________
From: "Bret Smith" <smithhb(at)tds.net>
Subject: Re: Fuse Block Locations
Date: May 13, 2008
John, I have the same setup as you. I also made a drop-down tray. http://www.flightinnovations.com/wiring.html Bret Smith RV-9A "Canopy" Blue Ridge, GA www.FlightInnovations.com ----- Original Message ----- From: "John Morgensen" <john(at)morgensen.com> Sent: Tuesday, May 13, 2008 9:30 AM Subject: AeroElectric-List: Fuse Block Locations > > > I am seeking pictures and advice on fuse block locations, panel ground, > firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture. > > Thanks, > John Morgensen > 775 771-5791 > > > ________________________________________________________________________________
Date: May 13, 2008
Subject: Fuse Block Locations
From: James H Nelson <rv9jim(at)juno.com>
John, There are many positions but you need to examine your requirements. I am using the 13-8 system. I put my drop down panel just to the right of the left side vent. Look at my pix on my web site. http://www.websites.expercraft.com/jimn Then scroll down on the left side to Panel, then to flight instrument and then to Oct 6 2005. I mounted my ground system very close to the fire wall pass through. I used a stainless steel handicap grab bar as my starting structure. I cut off one end which gave my a 90* ell as it passed into the engine compartment. In my pic. you can see where I put the ground block for each side. There is one thing I needed to do and that is to use a bigger (more terminals) ground block on the cabin side. I ended up putting some grounds thru the pass thru and hooking up to the ground bolck on the engine side. Count up the number of grounds you think you will need and then add at least 50% to that number. I also put my "always hot" fuse block very close to the firewall. This way I can run the always hot lead thru the fire wall and directly to the fuse block. Since it is short, it will not need protection. Lots of ideas, just freeze it and build it. Jim 99% done, 20% to go ________________________________________________________________________________
From: "Greg Young" <gyoung@cs-sol.com>
Subject: Fuse Block Locations
Date: May 13, 2008
I mounted my fuse blocks directly to the fuselage side - dimpled the skin and countersunk the holes in the blocks. They'll be covered by a sidewall panel when the interior goes in. Regards, Greg Young > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On > Behalf Of John Morgensen > Sent: Tuesday, May 13, 2008 8:31 AM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Fuse Block Locations > > --> > > I am seeking pictures and advice on fuse block locations, > panel ground, firewall ground, etc. My project is an RV-9A > using a Z-13/8 architecture. > > Thanks, > John Morgensen > 775 771-5791 > > ________________________________________________________________________________
Subject: Use of 700-2-10 switch for nav/strobe combo lights
Date: May 13, 2008
From: <longg(at)pjm.com>
I am using the 2-10 as defined in the manual to turn on the nav lights in the center position and then add the strobe lights in the up position. Sounds simple enough. When I first turn on the nav lights, the strobe lights start blinking. I then add the strobe lights to the nav lights and they work normally. After cycling the switch once, only the nav lights come on at the first position (desired) and I can add the strobe lights by moving the switch to the top position. The behavior does not repeat itself unless the switch is turned off for a period of time. I have wired as described in Bob's manual. I am using the strobe/nav combo from ________________________________________________________________________________
Date: May 13, 2008
From: John Morgensen <john(at)morgensen.com>
Subject: Re: Fuse Block Locations
Thanks for all the responses! john John Morgensen wrote: > > > I am seeking pictures and advice on fuse block locations, panel > ground, firewall ground, etc. My project is an RV-9A using a Z-13/8 > architecture. > > Thanks, > John Morgensen > 775 771-5791 > ________________________________________________________________________________
Date: May 13, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Use of 700-2-10 switch for nav/strobe combo lights
>I am using the 2-10 as defined in the manual to turn on the nav lights in >the center position and then add the strobe lights in the up position. >Sounds simple enough. When I first turn on the nav lights, the strobe >lights start blinking. I then add the strobe lights to the nav lights and >they work normally. > >After cycling the switch once, only the nav lights come on at the first >position (desired) and I can add the strobe lights by moving the switch to >the top position. The behavior does not repeat itself unless the switch is >turned off for a period of time. The only thing that can cause unexpected sequencing is a faulty switch. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
From: "Dennis Jones" <djones(at)northboone.net>
Subject: Antenna coax splice
Date: May 13, 2008
What ramifications if any are there to using a connector to extend the run for antenna coax? Or should I start over and run it as a single cable? Thanks Jonsey ________________________________________________________________________________
Date: May 13, 2008
From: Bill Putney <billp(at)wwpc.com>
Subject: Re: Antenna coax splice
Dennis, If you are using BNC or TNC connectors and good quality cable you should be able to extend almost any antenna cable in your airplane. A connector adds .25-.5 db loss per connector. Anything should be able to handle this extra loss without a detectable loss in performance. - Bill You can "splice" the cable by Dennis Jones wrote: > What ramifications if any are there to using a connector to extend the > run for antenna coax? Or should I start over and run it as a single cable? > > > Thanks > Jonsey > * > > > * ________________________________________________________________________________
Date: May 13, 2008
From: "RALPH HOOVER" <hooverra(at)verizon.net>
Subject: Fuse Block Locations
John, Here is yet another hinged option. This fuse block uses insert able crimped contacts (no fastons and one less electrical interface). It is also split 20 Main Buss, 8 Essential Buss. The two buses are tied by a schottky diode bolted to brass busses (the stuff in the center of the rear of the panel). The fuse panel swings down and forward from the front edge of the panel and all of the wiring is in the rear. Ralph & Laura Hoover RV7A N527LR -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of John Morgensen Sent: Tuesday, May 13, 2008 9:31 AM Subject: AeroElectric-List: Fuse Block Locations I am seeking pictures and advice on fuse block locations, panel ground, firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture. Thanks, John Morgensen 775 771-5791 ________________________________________________________________________________
Date: May 13, 2008
From: "RALPH HOOVER" <hooverra(at)verizon.net>
Subject: Fuse Block Locations
I didn't mention that the Battery Buss fuse block is a 6 fuse surface mount block like others you have seen. It is mounted on the Forward side of the firewall inboard of the Brake fluid reservoir. Ralph -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of John Morgensen Sent: Tuesday, May 13, 2008 9:31 AM Subject: AeroElectric-List: Fuse Block Locations I am seeking pictures and advice on fuse block locations, panel ground, firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture. Thanks, John Morgensen 775 771-5791 ________________________________________________________________________________
From: "Allen Fulmer" <afulmer(at)charter.net>
Subject: Fuse Block Locations
Date: May 13, 2008
My favorite so far! And where, pray tell, did you get that beautiful fuse block with cover? Surely must be automotive! Allen Fulmer RV7 Avionics and Electrical >>>-----Original Message----- >>>From: owner-aeroelectric-list-server(at)matronics.com >>>[mailto:owner-aeroelectric-list-server(at)matronics.com]On >>>Behalf Of RALPH >>>HOOVER >>>Sent: Tuesday, May 13, 2008 8:43 PM >>>To: aeroelectric-list(at)matronics.com >>>Subject: RE: AeroElectric-List: Fuse Block Locations >>> >>> >>>John, >>> Here is yet another hinged option. This fuse block uses >>>insert able >>>crimped contacts (no fastons and one less electrical >>>interface). It is also >>>split 20 Main Buss, 8 Essential Buss. The two buses are tied >>>by a schottky >>>diode bolted to brass busses (the stuff in the center of the >>>rear of the >>>panel). The fuse panel swings down and forward from the >>>front edge of the >>>panel and all of the wiring is in the rear. >>> >>>Ralph & Laura Hoover >>>RV7A N527LR >>> >>>-----Original Message----- >>>From: owner-aeroelectric-list-server(at)matronics.com >>>[mailto:owner-aeroelectric-list-server(at)matronics.com] On >>>Behalf Of John >>>Morgensen >>>Sent: Tuesday, May 13, 2008 9:31 AM >>>To: aeroelectric-list(at)matronics.com >>>Subject: AeroElectric-List: Fuse Block Locations >>> >>> >>> >>>I am seeking pictures and advice on fuse block locations, >>>panel ground, >>>firewall ground, etc. My project is an RV-9A using a Z-13/8 >>>architecture. >>> >>>Thanks, >>>John Morgensen >>>775 771-5791 >>> >>> >>> >>> ________________________________________________________________________________
From: Fiveonepw(at)aol.com
Date: May 13, 2008
Subject: Re: Fuse Block Locations
In a message dated 05/13/2008 8:59:52 AM Central Daylight Time, rhdudley1(at)bellsouth.net writes: > I am seeking pictures and advice on fuse block locations, panel ground, > firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture. >>> I recently helped with wiring on a -7A and came up with a solution that worked out pretty well. Radio stack is centered on panel, dual GRT EFIS, ADI, A/P & EIS4000 on pilots side, nothing but blank panel on right. Made this area into a large glovebox, with a door that was the same shape as the dual EFIS panels, hinged at the bottom. All four fuse blocks are mounted directly to the sub-panel behind the glove box. The glovebox has a bottom-hinged rear panel that exposes the fuse blocks, with a fuse legend on its back side. You simply open the glovebox door, pull out anything in the way, pull down the cover panel (held with velcro), and all the fuses are right there. The empty slots have spare fuses as indicated by the legend. Photos if ya really want them- Still brain-fartin' at The PossumWorks in TN Mark **************Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. (http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001) ________________________________________________________________________________
Subject: Re: PMA-6000 intercom 28V install
Date: May 14, 2008
From: Etienne Phillips <etienne.phillips(at)gmail.com>
You're quite right Ralph, there is a noise concern. I doubt that the noise would be of a value that would cause damage, so my suggestion would be to try it, and if it doesn't work then replace it with a resistor... An alternative would be to use a switcher to get from 28V to 14V, then use an analogue voltage regulator to go to 12V. Something like a 7812 chip (connection details are identical to that of the switcher) would work quite nicely, and would only dissipate 2W at 1A, which is still somewhat better than 15W! You could also smooth the noise by putting a few (around 5) 100uF capacitors in parallel, upstream and downstream of the switching regulator. I suggest this rather than a two 500uF caps, as it will handle a much wider range of noise frequencies, as well as offer a degree of redundancy. They could even be wired into the loom at regular intervals between the bus, switcher and intercom ;-) I'm of a mindset that anything that gets hot will eventually cause problems somewhere... Also in case of an alternator failure, the last thing you want is for some minor component to start wasting precious energy by converting it to heat! I hope that this helps :-) Etienne On 09 May 2008, at 1:04 PM, RALPH HOOVER wrote: > Etienne, > > I suspect that PS engineering is using an analog regulator for > noise concerns (cost can figure in as well). Use care inserting a > switcher without properly considering the noise concern. A switcher > would certainly allow for a wide input voltage range without a lot > of heat. Not a show stopper but a design challenge to address. > This is just my take I have no knowledge of PS Engineering=92s design > or the process and decisions they have taken to arrive at their > design. I have used a switcher for my ANR power supply I=92ll soon > find out if I have any issues! > > Ralph & Laura Hoover > RV7A N527LR ________________________________________________________________________________
Date: May 14, 2008
From: "RALPH HOOVER" <hooverra(at)verizon.net>
Subject: Fuse Block Locations
Allen, I found it on the internet, I will search my records and see if I can find out where. I have lost a bunch of stuff due to a computer crash. I will be on the road for a few days so I will look when I return. It is a Bussman product 15710 series. Ralph -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Allen Fulmer Sent: Tuesday, May 13, 2008 10:10 PM Subject: RE: AeroElectric-List: Fuse Block Locations My favorite so far! And where, pray tell, did you get that beautiful fuse block with cover? Surely must be automotive! Allen Fulmer RV7 Avionics and Electrical >>>-----Original Message----- >>>From: owner-aeroelectric-list-server(at)matronics.com >>>[mailto:owner-aeroelectric-list-server(at)matronics.com]On >>>Behalf Of RALPH >>>HOOVER >>>Sent: Tuesday, May 13, 2008 8:43 PM >>>To: aeroelectric-list(at)matronics.com >>>Subject: RE: AeroElectric-List: Fuse Block Locations >>> >>> >>>John, >>> Here is yet another hinged option. This fuse block uses >>>insert able >>>crimped contacts (no fastons and one less electrical >>>interface). It is also >>>split 20 Main Buss, 8 Essential Buss. The two buses are tied >>>by a schottky >>>diode bolted to brass busses (the stuff in the center of the >>>rear of the >>>panel). The fuse panel swings down and forward from the >>>front edge of the >>>panel and all of the wiring is in the rear. >>> >>>Ralph & Laura Hoover >>>RV7A N527LR >>> >>>-----Original Message----- >>>From: owner-aeroelectric-list-server(at)matronics.com >>>[mailto:owner-aeroelectric-list-server(at)matronics.com] On >>>Behalf Of John >>>Morgensen >>>Sent: Tuesday, May 13, 2008 9:31 AM >>>To: aeroelectric-list(at)matronics.com >>>Subject: AeroElectric-List: Fuse Block Locations >>> >>> >>> >>>I am seeking pictures and advice on fuse block locations, >>>panel ground, >>>firewall ground, etc. My project is an RV-9A using a Z-13/8 >>>architecture. >>> >>>Thanks, >>>John Morgensen >>>775 771-5791 >>> >>> >>> >>> ________________________________________________________________________________
Date: May 14, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: PMA-6000 intercom 28V install
>PS Engineering s PMA-6000 intercom has the following note: > > >To reduce the amount of heat dissipated in the audio selector panel, when >used in a 28 > >Volt aircraft, it is required that the 15-Ohm, 15-Watt dropping resistor >(p/n 701-015-1501) be in- > >stalled in series with the power input. > > >The install manual goes on to say failure to do so will generate >unnecessary heat inside the unit and may void PS Engineering s warranty >. Does anyone have experience installing one of these units in a 28V >environment? Is the dropping resistor really required? The only reason I >ask is the local radio shops don t seem to know much about it which makes >me wonder if they ever used them. They all say they can order one but >nobody has one in stock. It is risky to disregard the words of the manufacturer's installation manuals. It's also disappointing that the manufacturers of this device did not craft a user-friendly design. The simplest thing to do is comply with the instructions. The simplest way to do this is acquire a component like this: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=FVTS10-15-ND Note that it can be mounted to some handy, out of the way surface on a long screw. The data sheet at: http://www.heiresistors.com/PDF/FVT_FST20%20spec.pdf tells us the hole through the middle of this device is 0.19" in diameter . . . The drill versus threaded sizes chart at: http://www.phy.mtu.edu/~suits/tapsizes.html says this is too small for a 10-32 screw but will be just fine for an 8-32. The resistor data sheet suggests we need one with 2" or so of over-all length. You'll be cranking a hard force down against a ceramic tube. Put a soft washer (some kind of rubber, plastic or even two layers of paper from the box that comes with a tube of toothpaste) between the end of the resistor and the mounting surface. Tighten the screw down to finger tight + 1 turn and spot the threads with some runny super-glue to keep it from drifting off that pressure setting. If your resistor comes with wires, clip them off. Attach lead wires for intercom power to the resistor's solder-tabs. Put double layer of heat-shrink over these joints for vibration support. This process has been used thousands of designs in various vehicular products including airplanes. Simple, lean, works as the manufacturer wishes and lasts a long time. BTW . . . the 15W rating is super conservative. The intercom may draw 1A peak current but the AVERAGE current will be much lower unless you're particularly fond of playing Wagner at 100dB in the headphones. Now, if you're REALLY wanting to make this more complicated, you can purchase one of B&C's DIM3-28 dimmers at: http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?10X358218#dim3-28 and instead of installing the dimmer potentiometer, you put the appropriate resistor between pins 1 and 3 to achieve a constant 14-volt output from the "dimmer". Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
From: "Henry Trzeciakowski" <hammer408(at)comcast.net>
Subject: Re: Fuse Block Locations
Date: May 14, 2008
John: I'm also building an RV 9tip-up, but I did not go with a hinged panel. My thought was that it should be very rare that I need to change fuses. If I do, it will be on the ground and all I'd have to do is back under the passanger side to change or troubleshoot. When I mounted them, I didn't take any pictures before I removed my sub-panel, but plan on it when I rivet my sub-panel on for the last time. That said, I mounted the Main Bus and Diode and heatsink (25watt - B&C) on the outboard side of the 745rib on the passanger side and used nutplates. I mounted the Eudurance Bus, which will basically be my avionics bus, on the inboard surface of the same rib. That way the e-bus will be just about 8 " from my avionic's stack. The Battery Bus I mounted just below the brake reservior and to the left of the battery. So'll I have a shor run to the Master Battery COntactor and no unfused wires penetrating the firewall. I purchased a fuse block with cover, so I wouldn't have issues with dirt, grease, etc. When I get pictures, I'll get them to you.. Henry ----- Original Message ----- From: "John Morgensen" <john(at)morgensen.com> Sent: Tuesday, May 13, 2008 6:30 AM Subject: AeroElectric-List: Fuse Block Locations > > I am seeking pictures and advice on fuse block locations, panel ground, > firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture. > > Thanks, > John Morgensen > 775 771-5791 > > ________________________________________________________________________________
From: "Terry McMillan" <terryml5c2p6(at)sympatico.ca>
Subject: Dual redundant electrical system
Date: May 14, 2008
This is my first time on the AeroElectric list server, though Ive been lurking in the forums for some time. Im looking for comments/critiques on a dual alternator dual battery system Ive designed. Right off the bat I have to acknowledge the contributions made in this area by Bob Knucolls, Ive read his book several times, and his ideas and philosophies have strongly influenced my design. Greg Richter of Blue Mountain Avionics has also been a major source of information and inspiration. My application is an all-electric plane, an RV7 Im building with Aerosance FADEC and an all-glass cockpit (AFS3400, GRT Horizon HX, and Trutrak EFIS). Im an electrical engineer with 22 years experience in a large electrical power utility doing protection and control work. Duplicate redundant protection systems for ultra high reliability are the core work in this field. In 1988 I left to start my own company, designing and manufacturing complex expensive microprocessor-based test equipment for use in that field. Ive flown my own Cessna 172 since 1992. Im comfortable with electricity and flying, but Im incorporating some non-standard ideas in this design and would appreciate comments. My prime concern is technical/safety aspects of the electrical system, but ergonomics is something Ive also considered important, and feel is too often neglected in the design of complex hardware systems. Ive attached reduced size jpg files to respect the bandwidth guidelines, based on the original dxf files, but will verbally describe the unusual aspects as well. I can also make available the dxf files showing clearer detail if anyone wants them. The first component after the battery in most aircraft systems is the master relay, which isolates both the starter solenoid and the feed to the main and/or essential buses. Its usually a large heavy solenoid that must be rated to carry starter current but normally carries only a small fraction of that current, and it takes about an amp to keep it picked up. My design uses a 60A ANL fuse at the battery, feeding a heavy-duty automotive 70A relay in the cockpit next to the master switch and fuse bus. I expect the smaller lighter relay will be more reliable than a $17 solenoid, especially because it is in a cooler lower vibration location, plus it will draw only one-tenth of the hold-in current which means more flying time in the event of battery only operation. In my specific system this is not insignificant, the 2 amp draw of two master relays would be ~10% of the typical main bus load. In a conventional system, there is no high-speed protection of the several feet of cable that can exist from the master relay through the firewall to the buses, other than how fast the pilot can smell smoking insulation and turn off the switch, by which time major damage can be done to the wiring bundle. Once I discovered ANL fuses, I saw they could offer fast automatic protection of this major cable run. There are some good photos at http://www.highrf.com/gallery/Power-Grids of a Legacy power grid using ANL fuses. In my system, because I require separate FADEC buses, Ive used an additional fuse plus relay and fuse bus mounted at the battery, to eliminate power wiring runs into and then back out of the cockpit, which cuts weight, simplifies wiring, and minimizes wiring exposure to damage. A reason given for the conventional system layout is that it can isolate a stuck starter solenoid. In my experience however, properly sized starter solenoids are far more likely to fail open than closed, especially since there is often an additional solenoid internal to the starter, and in worst case its an on-ground event. The master relays are controlled by double pole 3 position rocker switches with internal LED annunciators (see attached Switchgear.jpg). This allows replacement of the traditional split control switch by providing a battery only/alternator disabled configuration in the middle position, with the normal configuration in the upper position. Illuminated rocker switches, apart from being more visually appealing than the typical steel toggle switch, can provide rapid day/night visual confirmation of true operational status since the indicator is driven by the voltage of the actual controlled circuit. Arranging the switches in close functional groupings also makes it easy for pre-landing checks- just brush a finger across the tops of all the switches to verify they are in the upper position. >From there, power flows to the master bus via 60A Schottky diodes, which generate much less heat than conventional diodes, reducing heat sink requirements. There is only one main bus. I spent a lot of time trying to decide what would go on an essential bus and what would not, plus considering what kind of interlocks and switching would be necessary to operate from the essential bus. In the end, given my dual batteries, dual alternators, and better protection of the main battery feed lines, I realized that a large essential bus is just as secure as a small one, and not having to set up an emergency configuration during a high-stress situation is a big advantage. Greg Richters comments about unnecessarily complex emergency systems (page 7 of his Aircraft Wiring pdf) are spot on in my opinion. Modern avionics and LED nav & panel lights dont draw a lot of power, so normal daytime flight requirements are well under 20 amps for my setup, which can be carried by the 20A backup alternator, never mind the dual batteries. Many engine monitor systems, like the AFS3400, can monitor alternator loading and bus voltage plus provide programmable high/low limit alarms to these parameters, helping to keep track of loading during loss of a power source. I dont have an avionics master switch. I know this is controversial, and apposed to common procedure, but here is my rationale: 1) Modern avionics are not susceptible to switching transients the way a lot of earlier commercial gear was, especially during the early days of discrete transistors. Additionally, though its not shown on my schematics, diode suppression is fitted to all relays, something that wasnt usually done in the past. 2) A single avionics master switch provides a single contingency failure point for the avionics, after all the work to provide full redundancy. 3) Battery voltage drop during starting can cause some avionics to drop out, but because of the dual diode isolation of the main bus, the avionics will automatically be fed only from the normal-voltage alternate battery when the main battery sags during start. My fuel boost pump switch is a bit different in that there is an additional (AUTO) position, controlled by the FADEC system. However, takeoff/landing (MANUAL) position is up, consistent with the master switches, and as with them LED annunciators provide additional status information. There is no Pitot Heat control, this is a personal thing. Ive found that after flying the same plane for a while I rarely look at airspeed, and my setup gives me dual airspeed info plus AOA. Also, Im a VFR pilot. Doesnt mean I wont decide to add it if I hear compelling reasons to. Lighting is traditionally done with a row of toggle switches, one for every circuit, and here again I have departed from tradition, but in this case mainly with an eye to improved ergonomics. Details are on a separate drawing (Lights.jpg). Note that the labels on the rotary switch on the above panel layout jpg are one revision behind the schematic. I have shown just a 2-pole rotary switch, as high-reliability sealed switches usually have fewer configuration choices than cheaper switches. A single rotary switch, common in automotive applications, makes more sense to me than individual toggles. Just turn clockwise for more lights. The first position BEACON gives nav lights and strobes. Because strobes can be disorienting in reduced visibility they can be disabled via the STROBE ENABLE rocker switch, but the LED nav lights are always on given their miniscule power draw. APPROACH as shown energizes the landing lights in a wig-wag mode for high visibility, though this wouldnt appeal to everyone. TAXI and LANDING are the last two positions respectively. Taxi lights are on in both positions, but one rotation counterclockwise on the ground eliminates the long-range landing light to avoid glare to other pilots. The small rotary knob beside the larger lighting switch controls dimming of cockpit lights. The STROBE ENABLE rocker switch status LED gives instant visual confirmation of strobe status, and the tight group of 3 controls in their separate location can be operated by touch only, like the master and fuel boost controls. This is difficult to accomplish in the traditional row of identical toggle switches which are often mixed in with other identical toggle controls. I dont have panel controls for trim or flaps, these are provided on the pilot and copilot control stick handles. A junction box is provided as a convenient local plug-in terminus for the control stick switches, trim & flap servos and controller, radio control lines, and power/ground lines. I have a schematic of this if anyone wants to see it. My instrument panel will obviously have a lot fewer controls on it than is now common. I know that banks of toggle switches look impressive to the uninitiated, but realistically this doesnt contribute to safety by reducing the pilots workload. Colour coding and grouping can help a little bit, but it still leaves something to be desired for night operations and status checks by touch while keeping focused outside the cockpit. Thats about it for the design highlights. One thing not evident but also important is, wherever possible, separate physical routing of the main and alternate system wiring, including firewall penetrations. Ive tried to envision how the system would handle a variety of failures and havent come up yet with any realistic scenario that would bring the plane down before you could get to a reasonable destination point. My only minor concern at this point is how load sharing is controlled, since the secondary alternator is just 20A. Ive talked to Bill Bainbridge at B&C, and he said that he sets the voltage regulator about a volt lower on the alternate. This seems like a lot to me, Im not sure what effect this has on keeping the alternate battery in optimum condition. I couldnt find much in Bobs book or the forums on this point. Anyway, Im completely open to suggestions and/or criticism. Ego should never get in the way of safety. Id appreciate anything in the way of comment. Im now at the point of being almost ready to start wiring things up, and need a reality check that what I intend to do makes sense. Thanks, Terry McMillan ________________________________________________________________________________
Date: May 14, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: PMA-6000 intercom 28V install
>PS Engineering s PMA-6000 intercom has the following note: > > >To reduce the amount of heat dissipated in the audio selector panel, when >used in a 28 > >Volt aircraft, it is required that the 15-Ohm, 15-Watt dropping resistor >(p/n 701-015-1501) be in- > >stalled in series with the power input. > > >The install manual goes on to say failure to do so will generate >unnecessary heat inside the unit and may void PS Engineering s warranty >. Does anyone have experience installing one of these units in a 28V >environment? Is the dropping resistor really required? The only reason I >ask is the local radio shops don t seem to know much about it which makes >me wonder if they ever used them. They all say they can order one but >nobody has one in stock. It is risky to disregard the words of the manufacturer's installation manuals. It's also disappointing that the manufacturers of this device did not craft a user-friendly design. The simplest thing to do is comply with the instructions. The simplest way to do this is acquire a component like this: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=FVTS10-15-ND Note that it can be mounted to some handy, out of the way surface on a long screw. The data sheet at: http://www.heiresistors.com/PDF/FVT_FST20%20spec.pdf tells us the hole through the middle of this device is 0.19" in diameter . . . The drill versus threaded sizes chart at: http://www.phy.mtu.edu/~suits/tapsizes.html says this is too small for a 10-32 screw but will be just fine for an 8-32. The resistor data sheet suggests we need one with 2" or so of over-all length. You'll be cranking a hard force down against a ceramic tube. Put a soft washer (some kind of rubber, plastic or even two layers of paper from the box that comes with a tube of toothpaste) between the end of the resistor and the mounting surface. Tighten the screw down to finger tight + 1 turn and spot the threads with some runny super-glue to keep it from drifting off that pressure setting. If your resistor comes with wires, clip them off. Attach lead wires for intercom power to the resistor's solder-tabs. Put double layer of heat-shrink over these joints for vibration support. This process has been used thousands of designs in various vehicular products including airplanes. Simple, lean, works as the manufacturer wishes and lasts a long time. BTW . . . the 15W rating is super conservative. The intercom may draw 1A peak current but the AVERAGE current will be much lower unless you're particularly fond of playing Wagner at 100dB in the headphones. Now, if you're REALLY wanting to make this more complicated, you can purchase one of B&C's DIM3-28 dimmers at: http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?10X358218#dim3-28 and instead of installing the dimmer potentiometer, you put the appropriate resistor between pins 1 and 3 to achieve a constant 14-volt output from the "dimmer". Bob . . . ________________________________________________________________________________
From: "Peter Laurence" <PLaurence@the-beach.net>
Subject: Fuse Block Locations
Date: May 14, 2008
Allen, Try MIH Industries. That's where I purchased mine about a year ago. http://home.earthlink.net/~dswartzendruber/ Peter Laurence -----Original Message----- My favorite so far! And where, pray tell, did you get that beautiful fuse block with cover? Surely must be automotive! Allen Fulmer RV7 Avionics and Electrical ________________________________________________________________________________
Date: May 15, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Dual redundant electrical system
>X-MIME-Autoconverted: from 8bit to quoted-printable by matronics.com id >m4F09XD3009485 >Content-Type: text/plain; x-avg-checked=avg-ok-7F1173FE; format=flowed >I've attached reduced size jpg files to respect the bandwidth guidelines, >based on the original dxf files, but will verbally describe the unusual >aspects as well. I can also make available the dxf files showing clearer >detail if anyone wants them. Can you .pdf the .dxf drawings from your CAD application? The .jpg files are kind of "swiss-cheesy" difficult to deduce the details of your design. I'll .pdf them and repost. >The first component after the battery in most aircraft systems is the >master relay, which isolates both the starter solenoid and the feed to the >main and/or essential buses. It's usually a large heavy solenoid that must >be rated to carry starter current but normally carries only a small >fraction of that current, and it takes about an amp to keep it picked up. >My design uses a 60A ANL fuse at the battery, feeding a heavy-duty >automotive 70A relay in the cockpit next to the master switch and fuse >bus. I expect the smaller lighter relay will be more reliable than a $17 >solenoid, especially because it is in a cooler lower vibration location, >plus it will draw only one-tenth of the hold-in current which means more >flying time in the event of battery only operation. In my specific system >this is not insignificant, the 2 amp draw of two master relays would be >~10% of the typical main bus load. Terry, you've obviously spent a great deal of time and thought on this. At first blush, the system you propose is a relative of Figure Z-14 as published at: http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z14L_1.pdf http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z14L_2.pdf This dual-alternator/dual-battery architecture was crafted over a period of 15 or so years and embodies practices well demonstrated in aircraft for over 60 years. >Anyway, I'm completely open to suggestions and/or criticism. Ego should >never get in the way of safety. I'd appreciate anything in the way of >comment. I'm now at the point of being almost ready to start wiring things >up, and need a reality check that what I intend to do makes sense. What you've proposed will probably function as you envision it. It's more complex than the Z-14 drawings in many respects and may not meet design goals for aircraft systems design where we strive for low parts count and failure tolerance. This translates directly to reductions in weight, cost, and pilot workload. This approach also increases reliability . . . a part that isn't there cannot be a failure item in your finished system. You've cited rationale for features of your proposed system that are not a concern for most folks in aviation. It would be a much more direct path to "architectural nirvana" to build on what's gone before than to stir a bunch of parts into a totally new recipe. At the risk of sounding like I'm suffering a "not invented here" moment, could you take a bit of time and tell us where you perceive that Z-14 does not meet personal design goals? Bob . . . ________________________________________________________________________________
Date: May 15, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: PMA-6000 Intercom - 28v install
>PS Engineering s PMA-6000 intercom has the following note: > > >To reduce the amount of heat dissipated in the audio selector panel, when >used in a 28 > >Volt aircraft, it is required that the 15-Ohm, 15-Watt dropping resistor >(p/n 701-015-1501) be in- > >stalled in series with the power input. > > >The install manual goes on to say failure to do so will generate >unnecessary heat inside the unit and may void PS Engineering s warranty >. Does anyone have experience installing one of these units in a 28V >environment? Is the dropping resistor really required? The only reason I >ask is the local radio shops don t seem to know much about it which makes >me wonder if they ever used them. They all say they can order one but >nobody has one in stock. It is risky to disregard the words of the manufacturer's installation manuals. It's also disappointing that the manufacturers of this device did not craft a user-friendly design. The simplest thing to do is comply with the instructions. The simplest way to do this is acquire a component like this: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=FVTS10-15-ND Note that it can be mounted to some handy, out of the way surface on a long screw. The data sheet at: http://www.heiresistors.com/PDF/FVT_FST20%20spec.pdf tells us the hole through the middle of this device is 0.19" in diameter . . . The drill versus threaded sizes chart at: http://www.phy.mtu.edu/~suits/tapsizes.html says this is too small for a 10-32 screw but will be just fine for an 8-32. The resistor data sheet suggests we need one with 2" or so of over-all length. You'll be cranking a hard force down against a ceramic tube. Put a soft washer (some kind of rubber, plastic or even two layers of paper from the box that comes with a tube of toothpaste) between the end of the resistor and the mounting surface. Tighten the screw down to finger tight + 1 turn and spot the threads with some runny super-glue to keep it from drifting off that pressure setting. If your resistor comes with wires, clip them off. Attach lead wires for intercom power to the resistor's solder-tabs. Put double layer of heat-shrink over these joints for vibration support. This process has been used thousands of designs in various vehicular products including airplanes. Simple, lean, works as the manufacturer wishes and lasts a long time. BTW . . . the 15W rating is super conservative. The intercom may draw 1A peak current but the AVERAGE current will be much lower unless you're particularly fond of playing Wagner at 100dB in the headphones. Now, if you're REALLY wanting to make this more complicated, you can purchase one of B&C's DIM3-28 dimmers at: http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?10X358218#dim3-28 and instead of installing the dimmer potentiometer, you put the appropriate resistor between pins 1 and 3 to achieve a constant 14-volt output from the "dimmer". Bob . . . ________________________________________________________________________________
From: "Dr. Andrew Elliott" <a.s.elliott(at)cox.net>
Subject: Avoiding strobe noise?
Date: May 15, 2008
I am building a 601XL (all aluminum), and have located the COMM antenna on the bottom of the fuselage between the seats. (It's a taildragger, so this is behind the gear.) I have the primary battery under the right seat and am holding off locating the second battery until I see how the W&B turns out. It has turned out to be convenient, wiring-wise, to locate the strobe power supply, an XPAK-604X-HR, under the left seat. In this location, the coax to the COMM antenna and at least one of the wires to the strobe heads will end up in close proximity. My question is: Assuming the coax is properly terminated and the strobe cables' shields are properly grounded at one end, is there going to be a problem with strobe noise interfering with communications? (The strobe cables have a foil shield with a drain wire. The drain wire is grounded to the wing structure at the tip.) If a problem is likely, are there any additional precautions I could take to avoid one? Thanks, Andy Elliott, Mesa, AZ N601GE (reserved) 601XL/TD, Corvair, building... ________________________________________________________________________________
Date: May 15, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Avoiding strobe noise?
>I am building a 601XL (all aluminum), and have located the COMM antenna on >the bottom of the fuselage between the seats. (It's a taildragger, so >this is behind the gear.) I have the primary battery under the right seat >and am holding off locating the second battery until I see how the W&B >turns out. > >It has turned out to be convenient, wiring-wise, to locate the strobe >power supply, an XPAK-604X-HR, under the left seat. In this location, the >coax to the COMM antenna and at least one of the wires to the strobe heads >will end up in close proximity. > >My question is: Assuming the coax is properly terminated and the strobe >cables' shields are properly grounded at one end, is there going to be a >problem with strobe noise interfering with communications? (The strobe >cables have a foil shield with a drain wire. The drain wire is grounded to >the wing structure at the tip.) > >If a problem is likely, are there any additional precautions I could take >to avoid one? > Every time someone reports a "noise problem cured by repositioning wiring" it was a demonstration of some OTHER root cause. When products are qualified to be used on airplanes, they are qualified to both control emissions and withstand certain stresses that are known to exist in the aircraft environment. The wiring you've cited are not particularly communicative with respect to noise . . . assuming that the installation of said wires is in accordance with manufacturer's instructions. In the heavy iron birds, we are seldom blessed with enough room to run all the wires that are necessary for operation much less comb them into potentially antagonistic and/or victim systems. The short answer is run them neatly together and you'll be fine. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Subject: Re: PMA-6000 intercom 28V install
From: "rampil" <ira.rampil(at)gmail.com>
Date: May 15, 2008
To be clear, a switching power brick (aka DC-DC converter) turns DC into AC then processes it and reconverts to DC. This process makes audio and potentially RF noise. Noise injected into your intercom will be a much worse problem than an old resistor hung on your firewall. A resistor should also be about 1/10 the cost of a power brick. I would guess available of amps to squander in a voltage dropping resistor would not be an issue in your RV-10. Cheers, -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=183349#183349 ________________________________________________________________________________
Date: May 16, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: PMA-6000 intercom 28V install
> >To be clear, a switching power brick (aka DC-DC converter) turns DC >into AC then processes it and reconverts to DC. This process makes >audio and potentially RF noise. Noise injected into your intercom >will be a much worse problem than an old resistor hung on your firewall. DC to DC converters come in all flavors. Modern devices have internal operating frequencies in the hundreds of kilohertz and generally do not present a noise issue to audio systems. They have been BIG issues to low frequency nav aids like VLF Omega and LORAN but few folks use these technologies. The next most vulnerable system would be an AM radio . . . generally used for listening to ball games while airborne. They have packaging issues. I'm aware of no bolt-in-and-wire- it-up product suited to this task. DC to DC converters come packaged as components for a larger assembly. Here's an exemplar device: http://www.lambdapower.com/ftp/Manuals/pxe_single_ins.pdf So after you've selected a device with the right power ratings, now you have to put it in a package of some kind with screw terminals, push on tabs or perhaps a connector of some kind. Of course this also offers an opportunity to add whatever filtering is necessary to live responsibly with the DO-160 rules of engagement. >A resistor should also be about 1/10 the cost of a power brick. I >would guess available of amps to squander in a voltage dropping resistor >would not be an issue in your RV-10. Dropping resistors are, as a rule, to be avoided if there are more elegant solutions at hand. Back when 12v cars were coming into the marketplace, one could purchase a "Glo-Bar" resistor designed to drop 12v down to 6v for the purpose of installing a legacy 6v radio in a new 12v car. These ran rather warm (30 watts or so) and the "squandering" of energy was significant but not overtaxing to the system that produced 300+ watts. In this case, we're considering a system that draws perhaps 100 mA in a quiescent state (1.5 volts dropped across the 15-ohm resistor and tossing off 150 MILLIwatts) and averages perhaps 300 mA while listening to some music (4.5v drop and 1.3 watts). Peak currents pushing 1A would run the PEAK dissipation in the dropping resistor up to 10-15 watts or so . . . but this is exceedingly transient . . . in a system that produces over 1000 watts of useable power makes this decision electrically trivial. The BIG driver in these deliberations is the hassle and expense of $time$ that it would take to put a DC to DC converter in a system that probably should have been fitted with such capabilities from the factory. Bob . . . ________________________________________________________________________________
Subject: Close to the battery
Date: May 16, 2008
From: <longg(at)pjm.com>
I have two of the six pack fuse blocks from B & C that I want to use for battery 1 & 2 respectively (Z19). The diagram indicates "close to the battery". I take that as on the firewall if batteries are mounted as such. Does anyone know if B & C or other makes covers for this fuse block? Naturally If I mount them on the firewall, I want to keep the rif-raf out. There's always duct tape, but we need a little style here. Thanks ________________________________________________________________________________
Date: May 16, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Close to the battery
> >I have two of the six pack fuse blocks from B & C that I want to use for >battery 1 & 2 respectively (Z19). The diagram indicates "close to the >battery". I take that as on the firewall if batteries are mounted as >such. > >Does anyone know if B & C or other makes covers for this fuse block? >Naturally If I mount them on the firewall, I want to keep the rif-raf >out. There's always duct tape, but we need a little style here. The easiest cover is to use threaded spacers as 'nuts' to mount the fuse block. Bring screws through the mounting surface and cut them just long enough to get good thread engagement. Make spacers long enough to extend just above the tops of seated fuses. Cut a plate of the right size to cover the block. You could consider bending flanges on it that would droop down over the fuses and offer more coverage. A piece of sheet rubber on the underside of the cover would let you screw the cover down 'solid' and still not put the supper-munch on the fuses. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: May 16, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Dual redundant electrical system
>Bob, thanks for the reply. As requested, I'm sending you the 2 schematic >files in .pdf format for reposting. They are much larger than the .dwg and >.dxf files, so I am sending them right to you rather than via the Matrox >file server. I can also give them to you in a variety of AutoCad formats >if that would be better. The .pdf files are fine. I've posted them to my server at: http://www.aeroelectric.com/_temp/ I'll invite folks on the List to go get them and participate in this thread as the spirit moves them . . . >I think from some of your comments that you may have misunderstood my >intentions in sending out a request for comments. I am not trying to >propose a new standard. The standard as far as I can see is your Z14 >design, I have seen numerous references to it in my research on the Net, >and as I indicated I have read your book several times. I have thoroughly >analysed Z13 and Z14. You have a lot of good ideas, which is why right up >front in my letter I acknowledged your contributions. However there are >some drawbacks to Z14 from my perspective, and since you have requested >it, I will mention a few specifics. below. Not at all. The works published in the 'Connection are not intended to be the "final solution". They're drawings that were evolved to meet certain design goals. >However, my intention was not to knock your design, but to see if in fact >anyone could find any safety or reliability flaws in something I came up >with. Also, it may be more obvious when you get a look at a clearer >drawing that a significant part of the complexity you refer to is due to >the AeroSance FADEC system. That is specified by AeroSance, not me, and >includes 2 additional switch controlled buses dedicated to the control >system, and their own starter switch, fuel pump control switch, and fuel >pump relay. Absolutely understand . . . and no offense taken. My mission with channeling this discussion is to offer it as a learning experience for folks on the List. Another element of the mission is to justify a modicum of my time to participate without asking for a indenturship documents on your first-born. We can increase the depth of the study by involving lots of folks on the List while not taxing my presently tight schedule. >Regarding the lighting circuit, if you concede that wig-wag landing lights >enhance safety, the traditional toggle-switch approach would require 5 >toggle switches; Nav, Strobes, Wig-Wag/Steady, Taxi and Landing. I don't >see how this could reduce pilot workload compared to a rotary switch plus >a rocker switch. The circuits behind those controls would appear less >complex if there was a readily-available high-reliability switch to >control each circuit directly, but for my application- again, I'm not >proposing this as a standard- 4 relays, a rocker and a rotary switch vs 5 >toggle switch is a good tradeoff against reduced pilot workload and more >time looking outside the cockpit. > >As requested, here are some reasons why Z14 did not meet my needs. One of >the things I wanted to ensure enhanced reliability was minimal firewall >penetration by power circuits, and fuse protection where this was >unavoidable. As I began looking at integrating Z14 with the FADEC >circuits, some conflicts became apparent. The RV7 standard battery >configuration is on the engine side of the firewall, and there are quite a >few power circuits to the FADEC on the engine side as well. Using a >grounding cockpit switch to remotely control the FADEC bus meant all the >critical power circuits for the FADEC would remain in the engine >compartment- shorter wires, fewer firewall penetrations, and greater >reliability. > >This still left an unavoidable firewall penetration by the main battery >feed to the cockpit circuitry however, and a fault on that extended cable >would do serious damage before it could be switched off manually via the >traditional master relay. Fuse protecting this line and using a lighter >lower power master relay in the cockpit right next to the bus it fed was >to me a logical step, I've already noted that I don't see isolating the >starter solenoid as necessary. > >There are 3 issues with the Z14 cross-feed contactor from my perspective. >First is that according to Bill Bainbridge of B&C I won't need to parallel >batteries with his starter. Second is that I would need an avionics master >switch- single contingency failure point and one more part to fail as you >have noted- to isolate the EFISs from the batteries during start. Third is >that if a fault appeared in the wrong spot-such as the unprotected line >between master relay and bus- switching in the cross-feed contactor to >bring on the backup alternator would immediately fail that circuit as >well. An additional objection to the circuit as shown, from my >perspective, is combining the starter and cross-feed control into a single >switch. If there is to be manual intervention required in an emergency, it >should be with a separate dedicated clearly marked switch, not the switch >you've used a thousand times to start the engine. > >The diode-isolated bus automatically brings the backup system on line (no >pilot intervention) to sustain the critical circuits, prevents backfeeding >into a fault on the failed side, and it is less complex and more reliable >than a manual switch, relay and warning lamp. > >Let me make it clear that I'm not bashing your design- you asked me why it >doesn't meet my personal goals, and that's what I've done. In fact, what >I've done above is what I was hoping to have done to my design; have clear >specific points made about what might be problematic. Comments like more >complex, may not meet design goals of failure tolerance, reduced weight & >workload etc don't really help me if I don't know where it fails in these >regards. Everyone benefits when specific construction criticism advances >the state of the art and/or encourages people to keep contributing new ideas. Very good sir. I've looked this over briefly but I'll throw it out to the folks on the List with the notion of joining in as time permits. Bob . . . ________________________________________________________________________________
Subject: Dynon , sl40, pm1000II, and GTX327 Pinout numbers
From: "gcarnforth" <greg(at)chesterpools.com>
Date: May 16, 2008
Hello! I have been motoring along on my RV7 and have always been able to find answers in the archives. I am having troubles firing up my panel and am in the process of going back through the harness. Does anyone have the pin numbers for connecting these units? Flightdek to GTX327 SL40 to PM1000II I have the diagrams but anyone with the pin numbers would help verify what I have done right/wrong Thanks G carnforth RV7 louisville KY -------- G. Carnforth Louisville, KY RV7 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=183459#183459 ________________________________________________________________________________
Date: May 16, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Close to the battery
> >Thanks Bob, > Great idea. I believe I have seen suitable spacers made from >nylock. We'll give it a go. You may need to make them. Got access to a lathe? If push comes to shove, you can use aluminum rod stock. Cut length just longer than you need for finished part. Chuck stock in drill press and grab bit in drill press vise. By turning the stock and holding drill stationary, you can take advantage of tendency for drill to center automatically. Start out with small pilot drill and then finally drill with size appropriate to thread size you plan to use (probably 6-32 or 8-32). Tread both ends of the part before sanding carefully to achieve proper length and flatness of ends. Then use countersink or oversized drill to chamfer/de-burr edges of finished holes. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Subject: Dynon , sl40, pm1000II, and GTX327 Pinout numbers
Date: May 16, 2008
From: <longg(at)pjm.com>
G. Not to confuse you, but I have them for the Dynon, sl30 and GTX330. Not exact, but close family. If you get stuck, they may help. They are hard copy so I'll need to scan them in (Monday). I'll bet the sl40 is the same as the sl30 w/o the nav junk. Don't know about the 330 since it has different options than the 327. Thanks -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of gcarnforth Sent: Friday, May 16, 2008 1:54 PM Subject: AeroElectric-List: Dynon , sl40, pm1000II, and GTX327 Pinout numbers --> Hello! I have been motoring along on my RV7 and have always been able to find answers in the archives. I am having troubles firing up my panel and am in the process of going back through the harness. Does anyone have the pin numbers for connecting these units? Flightdek to GTX327 SL40 to PM1000II I have the diagrams but anyone with the pin numbers would help verify what I have done right/wrong Thanks G carnforth RV7 louisville KY -------- G. Carnforth Louisville, KY RV7 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=183459#183459 ________________________________________________________________________________
Date: May 16, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: ANL Distribution Panel
> >I was reading my Porsche Boxster repair manual the other day... > >Porsche uses a distribution box which has 5-6 ANL fuses mounted inside. >Picture it as a fuse block with hookups for ANL type fuses. The purpose >is to distribute current protected by various amperage ANL's to fuse >blocks segments which are organized by function and size. > >Has anyone attempted this kind of design and is there any value of which >surpasses the increased part count? The ANL style fuse is the easiest device to accommodate with a DIY fuse block. Further, know that there are some miniature siblings to the relatively 'boss-hogg' ANL devices. Here's an ANL base: http://www.aeroelectric.com/Pictures/Fuses/Fuse_Holders/ANN-ANL_Base.jpg Here's a base intended to mount the MEGA series current limiters: http://www.aeroelectric.com/Pictures/Fuses/Fuses/all_mega.JPG http://www.aeroelectric.com/Pictures/Fuses/Fuses/megafuse250.gif http://www.aeroelectric.com/Pictures/Fuses/Fuse_Holders/mfb736_angle.gif http://www.aeroelectric.com/Pictures/Fuses/Fuse_Holders/mfb736_dwg.jpg Here are some alternative, high current, stud mounted devices: http://www.aeroelectric.com/Pictures/Fuses/Fuses/ABI_fuses.jpg http://www.aeroelectric.com/Pictures/Fuses/Fuses/BF2.jpg The common thread for mounting these or similar fuses is a pair of sturdy, captive threaded posts. These can be steel bolts (we don't depend on bolt for current carrying). Fabricate a block from sturdy, insulating material like phenolic, Delrin, Polysulphone, etc. You need some sheet material with a thickness on the order of 1/2 to 5/8 inch. Drill hole pattern for installation of one or more fuses. Counter bore back side to take heads of bolts just under flush. Install bolts with one nut and no washer. Pot the head of the bolt with JB Weld. After epoxy sets up, remove nut and re=install using thread locker on nut. JB Weld works here too. Torque down real good. Of course, you'll need mounting holes in the base for installation. You may also need a copper sheet or brass bus-bar between studs at one end. Go 3/4" wide x .062 or more thickness. After the stud-nuts cure, install in a/c and set your fuse down first before stacking terminals onto the studs. Put flat washer on and secure with fiber lock-nut torqued to value recommended by AC43.13 for steel parts of same size. Hold your wires stationary while applying final torque so that you avoid this: http://www.aeroelectric.com/Pictures/Fuses/Fuses/ANL_Twisted.jpg Once assembled, the system is quite stable due to rigidity of the potted heads on studs. Bottom line is that with a little time at the table saw, drill press and belt sander, you can build a perfectly acceptable fuse block for any of the many choices of stud-mounted protective devices. Here's a multi-fuse installation on a production aircraft: http://www.aeroelectric.com/Pictures/Wiring_Technique/Contactor_Interconnect/Contactor_Strap_3.jpg We COULD have made a much smaller and lighter installation from scratch but the qualification costs were prohibitive. You folks are not so hindered . . . Bob . . . ________________________________________________________________________________
From: "Henry Trzeciakowski" <hammer408(at)comcast.net>
Subject: Re: 6 AWG vs Copper Bar
Date: May 16, 2008
Bob: Insteard of using 6 AWG from starter contctor to Current Limiter, I want to use .063 copper bar...is that adequate or should I use .125. thanks ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> Sent: Thursday, May 15, 2008 12:33 PM Subject: Re: AeroElectric-List: Avoiding strobe noise? > > > >I am building a 601XL (all aluminum), and have located the COMM antenna on > >the bottom of the fuselage between the seats. (It's a taildragger, so > >this is behind the gear.) I have the primary battery under the right seat > >and am holding off locating the second battery until I see how the W&B > >turns out. > > > >It has turned out to be convenient, wiring-wise, to locate the strobe > >power supply, an XPAK-604X-HR, under the left seat. In this location, the > >coax to the COMM antenna and at least one of the wires to the strobe heads > >will end up in close proximity. > > > >My question is: Assuming the coax is properly terminated and the strobe > >cables' shields are properly grounded at one end, is there going to be a > >problem with strobe noise interfering with communications? (The strobe > >cables have a foil shield with a drain wire. The drain wire is grounded to > >the wing structure at the tip.) > > > >If a problem is likely, are there any additional precautions I could take > >to avoid one? > > > > Every time someone reports a "noise problem cured > by repositioning wiring" it was a demonstration of > some OTHER root cause. > > When products are qualified to be used on airplanes, > they are qualified to both control emissions and > withstand certain stresses that are known to exist > in the aircraft environment. > > The wiring you've cited are not particularly > communicative with respect to noise . . . assuming > that the installation of said wires is in accordance > with manufacturer's instructions. > > In the heavy iron birds, we are seldom blessed with > enough room to run all the wires that are necessary > for operation much less comb them into potentially > antagonistic and/or victim systems. > > The short answer is run them neatly together and > you'll be fine. > > Bob . . . > > > ----------------------------------------) > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > ---------------------------------------- > > ________________________________________________________________________________
From: "Henry Trzeciakowski" <hammer408(at)comcast.net>
Subject: Re: Avoiding strobe noise?
Date: May 16, 2008
So Bob: as long as all wires are installed and grounded per maunfacture's spec, running (stringing) wires like Strobe Power Supply, Nav/Com, Transponder, Flaps, Pitot Heat together along the bottom of a fuselage and thru bulkheads together are OK ? Hank ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> Sent: Thursday, May 15, 2008 12:33 PM Subject: Re: AeroElectric-List: Avoiding strobe noise? > > > >I am building a 601XL (all aluminum), and have located the COMM antenna on > >the bottom of the fuselage between the seats. (It's a taildragger, so > >this is behind the gear.) I have the primary battery under the right seat > >and am holding off locating the second battery until I see how the W&B > >turns out. > > > >It has turned out to be convenient, wiring-wise, to locate the strobe > >power supply, an XPAK-604X-HR, under the left seat. In this location, the > >coax to the COMM antenna and at least one of the wires to the strobe heads > >will end up in close proximity. > > > >My question is: Assuming the coax is properly terminated and the strobe > >cables' shields are properly grounded at one end, is there going to be a > >problem with strobe noise interfering with communications? (The strobe > >cables have a foil shield with a drain wire. The drain wire is grounded to > >the wing structure at the tip.) > > > >If a problem is likely, are there any additional precautions I could take > >to avoid one? > > > > Every time someone reports a "noise problem cured > by repositioning wiring" it was a demonstration of > some OTHER root cause. > > When products are qualified to be used on airplanes, > they are qualified to both control emissions and > withstand certain stresses that are known to exist > in the aircraft environment. > > The wiring you've cited are not particularly > communicative with respect to noise . . . assuming > that the installation of said wires is in accordance > with manufacturer's instructions. > > In the heavy iron birds, we are seldom blessed with > enough room to run all the wires that are necessary > for operation much less comb them into potentially > antagonistic and/or victim systems. > > The short answer is run them neatly together and > you'll be fine. > > Bob . . . > > > ----------------------------------------) > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > ---------------------------------------- > > ________________________________________________________________________________
Date: May 16, 2008
From: Ernest Christley <echristley(at)nc.rr.com>
Subject: Re: PMA-6000 intercom 28V install
Robert L. Nuckolls, III wrote: > > They have packaging issues. I'm aware of no bolt-in-and-wire- > it-up product suited to this task. DC to DC converters come > packaged as components for a larger assembly. Here's an > exemplar device: > check mpja.com part number 14335-PS They have a number of other DC-to-DC converters available, but if it was just one low power device, I would use a 4-legged bridge rectifier or eight, lined up on a circuit board. The negative output of one feeding the positive input of the next. No noise. Compact. Useful for several amps. -- http://www.ronpaultimeline.com ________________________________________________________________________________
Date: May 16, 2008
From: "Ron Quillin" <rjquillin(at)gmail.com>
Subject: Re: Dual redundant electrical system
On Fri, May 16, 2008 at 8:51 AM, Robert L. Nuckolls, III wrote: > > > > The .pdf files are fine. I've posted them to my > server at: > > http://www.aeroelectric.com/_temp/ > > I'll invite folks on the List to go get them and > participate in this thread as the spirit moves them . . . > Incomplete or incorrect url Bob? Ron Q. ________________________________________________________________________________
Date: May 16, 2008
From: "Ron Shannon" <rshannon(at)CRUZCOM.COM>
Subject: Re: Dual redundant electrical system
> > > > http://www.aeroelectric.com/_temp/ > > > > I'll invite folks on the List to go get them and > > participate in this thread as the spirit moves them . . . > > > > Incomplete or incorrect url Bob? > > Ron Q. > The link works from here. Note there is an underscore character preceding "temp". FWIW, as a former IT geek, I discouraged webmasters from using underscores in web URL's because when the whole link is automatically highlighted and the whole link becomes underscored (as it does in most email programs) the unaware reader may not realize there's a separate underscore character. If spacing is necessary, hyphens are better. Of course, spaces never work in a URL. Ron ________________________________________________________________________________
Date: May 16, 2008
Subject: Re: Dual redundant electrical system
From: Ron Quillin <rjquillin(at)gmail.com>
About 10-15 minutes after the post, it also worked for me... Sigh. Also paid to be an IT geek at work. Ron Q. At 17:57 5/16/2008, you wrote: > > <http://www.aeroelectric.com/_temp/>http://www.aeroelectric.com/_temp/ > > > > I'll invite folks on the List to go get them and > > participate in this thread as the spirit moves them . . . > > > >Incomplete or incorrect url Bob? > >Ron Q. > > >The link works from here. Note there is an underscore character >preceding "temp". > >FWIW, as a former IT geek, I discouraged webmasters from using >underscores in web URL's because when the whole link is >automatically highlighted and the whole link becomes underscored (as >it does in most email programs) the unaware reader may not realize >there's a separate underscore character. If spacing is necessary, >hyphens are better. Of course, spaces never work in a URL. > >Ron > > ><http://www.matronics.com/Navigator?AeroElectric-List>http://www.matronics.com/Navigator?AeroElectric-List ><http://www.matronics.com/contribution>http://www.matronics.com/contribution > ________________________________________________________________________________
Date: May 16, 2008
From: "Ron Shannon" <rshannon(at)CRUZCOM.COM>
Subject: Re: Dynon , sl40, pm1000II, and GTX327 Pinout numbers
On Fri, May 16, 2008 at 10:54 AM, gcarnforth wrote: > greg(at)chesterpools.com> > ... > Does anyone have the pin numbers for connecting these units? > > Flightdek to GTX327 > SL40 to PM1000II > SL-40 pin outs are: 1 DC power 2 (reserved) 3 RS232 serial data out (TxD) 4 TxKey,pulled low to transmit 5 (no contact -- do not connect) 6 speaker 7 mic ground 8 Mic 1 input 9 DC power ground 10 RS232 serial data in (RxD) 11 RS232 signal ground 12 Intercom select, pulled low to turn on intercom 13 Audio ground (speaker & headphone) 14 Headphone terminal out 15 Mic 1 input ________________________________________________________________________________
Date: May 16, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Dual redundant electrical system
> >On Fri, May 16, 2008 at 8:51 AM, Robert L. Nuckolls, III > wrote: > > > > > > > > > The .pdf files are fine. I've posted them to my > > server at: > > > > http://www.aeroelectric.com/_temp/ > > > > I'll invite folks on the List to go get them and > > participate in this thread as the spirit moves them . . . > > > >Incomplete or incorrect url Bob? Don't think so. This is a link to a directory where you will find two separate .pdf files each of which needs to be downloaded independently. This is not unlike the general files archives on my server like: http://www.aeroelectric.com/Pictures/ and http://www.aeroelectric.com/Reference_Docs/ where you don't get a particular document but a directory structure for many documents. You should be able to double-click the link cited and it should take you to the appropriate directory(ies). Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: May 16, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Avoiding strobe noise?
> > >So Bob: > >as long as all wires are installed and grounded per maunfacture's spec, >running (stringing) wires like Strobe Power Supply, Nav/Com, Transponder, >Flaps, Pitot Heat together along the bottom of a fuselage and thru bulkheads >together are OK ? yup . . / Bob . . . ________________________________________________________________________________
Date: May 16, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: 6 AWG vs Copper Bar
> > >Bob: > >Insteard of using 6 AWG from starter contctor to Current Limiter, I want to >use .063 copper bar...is that adequate or should I use .125. > >thanks .063 x .75" copper is fine. Bob . . . ________________________________________________________________________________
From: "Scott Freeman" <sgfreeman(at)smyth.net>
Subject: Schematic Review
Date: May 17, 2008
I am building an RV-7A. The panel will be all electric and set-up for light IFR. I have completed my schematic and would like some input since I am new at this electrical stuff. The basic configuration is a single alternator/two battery system. The primary and aux battery are the same size (17 amp-hr) and can both be used for starting. There is a main and essential (avionics) buss that can be isolated on either battery. I envision the modes to be: 1) Normal operation: Start with primary batt, run system off alternator and primary batt, only turn aux batt on long enough to "top off" its charge and then isolate it back off. 2) Alternator failure and/or main batt failure: Power the avionics buss with the isolated aux battery for emergency power until able to land. This will be up to 2 hours for the avionics. Note: If there is remaining power in the Primary Batt- I would be able to get some time with it also. 3) Ground Start- If the Primary Batt is drained during a hard start situation, the option to switch to the aux battery for start is there. Since these are smaller dry cells, I like this option. 4) Plan is to rotate the aux battery to the Main Battery every other year or as necessary and replace the aux battery with a fresh one. This will provide preventative maintenance for the batteries. Thanks for any input you can provide to make sure the schematic doesn't have errors. Scott Freeman ________________________________________________________________________________
From: "Terry McMillan" <terryml5c2p6(at)sympatico.ca>
Subject: Schematic Review
Date: May 17, 2008
Scott, a couple of things I noticed; you have 2 unprotected unswitched circuits directly connected to the Aux battery, namely the Aux Battery Bus and the Aux Battery Switch. These both pass thru the firewall to the cockpit, and if a fault to ground occured they could not be turned off. My suggestion would be an in-line fuse for the Aux Bat Bus, and move the feed to terminal 2 of the Aux Bat Master Switch to the other side of the Aux Bat Relay. As shown turning on the Aux Bat Switch will energize both the Main and Avionics buses, so presumably you would manually turn off the loads on the main bus. To me it would make more sense to wire the fuse-protected lead from the Aux Battery direct to the Aux Bat Avionics Master, this way it would be an emergency-only switch, and the Aux Batt Master switch would just be used to parallel the batteries for starting or to charge the Aux battery. Personally I see it as a bad idea to mix emergency control functions with routine functions on the same switch. FWIW, a good suggestion I've seen is to put the DC power receptacle on the alway-hot bus. One advantage of this is that you can recharge the battery on the ground without opening the cowling. Terry McMillan RV7 FADEC dual electrical >From: "Scott Freeman" <sgfreeman(at)smyth.net> >Reply-To: aeroelectric-list(at)matronics.com >To: >Subject: AeroElectric-List: Schematic Review >Date: Sat, 17 May 2008 12:00:56 -0400 > >I am building an RV-7A. The panel will be all electric and set-up for >light IFR. I have completed my schematic and would like some input since I >am new at this electrical stuff. > >The basic configuration is a single alternator/two battery system. The >primary and aux battery are the same size (17 amp-hr) and can both be used >for starting. There is a main and essential (avionics) buss that can be >isolated on either battery. > >I envision the modes to be: >1) Normal operation: Start with primary batt, run system off alternator and >primary batt, only turn aux batt on long enough to "top off" its charge and >then isolate it back off. > >2) Alternator failure and/or main batt failure: Power the avionics buss >with the isolated aux battery for emergency power until able to land. This >will be up to 2 hours for the avionics. Note: If there is remaining power >in the Primary Batt- I would be able to get some time with it also. > >3) Ground Start- If the Primary Batt is drained during a hard start >situation, the option to switch to the aux battery for start is there. >Since these are smaller dry cells, I like this option. > >4) Plan is to rotate the aux battery to the Main Battery every other year >or as necessary and replace the aux battery with a fresh one. This will >provide preventative maintenance for the batteries. > >Thanks for any input you can provide to make sure the schematic doesn't >have errors. > >Scott Freeman ><< N246SFElectricalSystemDesignRev2-forReview.xls >> ________________________________________________________________________________
From: BobsV35B(at)aol.com
Date: May 17, 2008
Subject: Schematic Review
Good Afternoon Scott, I keep seeing reference to Light IFR and an occasional reference to heavy IFR. Would you mind telling me what you consider to be light IFR? If you were on top of coastal fog with a two hundred foot ceiling below, would a full ILS to a fully approach lit runway be light or heavy IFR? Or, if you are enroute, constantly in cloud, but with ceilings along your route and at destination well above one thousand and three, would that be light IFR? I have a hard time discerning just what is meant by light IFR. Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator 628 West 86th Street Downers Grove, IL 60516 630 985-8502 Stearman N3977A Brookeridge Air Park LL22 Do Not Archive In a message dated 5/17/2008 11:08:54 A.M. Central Daylight Time, sgfreeman(at)smyth.net writes: I am building an RV-7A. The panel will be all electric and set-up for light IFR. **************Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. (http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001) ________________________________________________________________________________
From: BobsV35B(at)aol.com
Date: May 17, 2008
Subject: Re: Schematic Review
I Like It! l Like It!! Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator 628 West 86th Street Downers Grove, IL 60516 630 985-8502 Stearman N3977A Brookeridge Air Park LL22 In a message dated 5/17/2008 6:32:48 P.M. Central Daylight Time, icubob(at)newnorth.net writes: hi bob, light ifr is if i am right seat with a very competent and proficient ifr pilot. hard ifr is if i am solo! bob noffs **************Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. (http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001) ________________________________________________________________________________
From: "S. Ramirez" <simon(at)synchronousdesign.com>
Subject: Schematic Review
Date: May 17, 2008
Scott, your version of "light IFR" sounds like non-commercial flying to me. I think it's wise for us guys that don't fly in IMC too much to want to fly only in light IMC. Those are good rules, and the goods don't have to be there by a certain time. Simon Copyright C 2008 From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Scott Freeman Sent: Saturday, May 17, 2008 10:33 PM Subject: Re: Getting Off Topic, Was: AeroElectric-List: Schematic Review Bob, Sorry for the "light IFR" nomenclature. I knew after I sent it that it would probably raise some eyebrows. To me it means it means I have some personal limits that I want to stay within for single pilot IFR. Rule 1: Never fly on purpose into sustained IMC conditions Rule 2: Use IFR as a means to get on top only if the layer is less than 2000 ft thick. If it is more than 2000' thick, stay home. Rule 3: When ever possible, use IFR flight plans to work on flying skills and to have constant contact with ATC Rule 4: Use IFR to get down through a layer for an approach to an airport with ceilings at least 300 ft. above minimums. If ceilings are less than 300 above, try to find another airport that meets that criteria even if you miss getting home when you wanted. Rule 5: Never, Never, Never fly when the slightest possibility of icing conditions or sustained IMC conditions are forecast for any part of your route Rule 6: Practice VFR navigation, including pilotage and dead reckoning on a regular basis to keep well rounded Rule 7: Plan on sleeping on some airport couches once in a while Rule 8: Since we are human and things don't always go as we expect, practice, practice, and practice so if unfortunate and unforseen circumstances lead to one of the rules being violated, you can survive and come home to your family in one piece To me it boils down to the old saying: It is better to be on the ground wishing you were in the air than in the air wishing your were on the ground. Scott ________________________________________________________________________________
Date: May 18, 2008
From: "Sam Hoskins" <shoskins(at)MCHSI.COM>
Subject: Peer review - Z-19RB with RWS controller
________________________________________________________________________________
Date: May 18, 2008
From: "Sam Hoskins" <shoskins(at)MCHSI.COM>
Subject: Try it again. Z-19RB Peer Review
________________________________________________________________________________
Subject: Again? - Peer review - Z-19RB with RWS controller
From: "Sam" <sam.hoskins(at)GMAIL.COM>
Date: May 18, 2008
Bob & all, (third try at posting this request) I'm looking for a review of my electrical system, based on Z-19RB. This is a retrofit in my little 22 year-old composite Quickie Q-200. I do a lot of day VFR cross country with this little buggy and do some cross country racing. Since I am converting to "all electric" I would be interested in your thoughts about my proposed system which is attached as a PDF file. Besides the Dynon FlightDEK 180 the biggest change is the conversion to electronic fuel injection. I am using the EC-3 controller from Real World Solutions (RWS). You can see more about the controller here: http://www.rotaryaviation.com/eficont.html The EC-3 controller is divided into two sides, A & B. The fuel injector control and ignition outputs exit the box from a single connector via a shared relay. The controller can receive either a primary or secondary 12V power source. A few bullet points: * I am using a primary fuel pump and a backup fuel pump. I also have two transfer pumps. * I have not yet sized the batteries. * I have an existing AEC9005-201 low voltage monitor, without the relay control. * Output of the ECU will be shown on another page, perhaps later in the week. * I have not yet properly sized the fuses or the wires in this drawing. My concerns: * By the time I add strobes and position lights, I will have around 14 or 15 switches, which seems like a lot for a 650 lb. (empty weight) airplane. Is there a way I could minimize the switch count? * There seem to be a lot of components connected to the unswitched battery busses. I wonder if I should use CBs instead of fuses? * Since I rarely fly at night, is the main buss, as depicted, really needed? Maybe I could combine the main and E busses. Anything else? Your input is very welcome. Thanks! Sam Hoskins Murphysboro, IL http://samhoskins.blogspot.com/ -------- Sam Hoskins www.samhoskins.blogspot.com Read this topic online here: http://forums.matronics.com/viewtopic.php?p=183649#183649 Attachments: http://forums.matronics.com//files/n202sh_peer_review_01_178.pdf ________________________________________________________________________________
From: "Henry Trzeciakowski" <hammer408(at)comcast.net>
Subject: Re: Avoiding strobe noise?
Date: May 18, 2008
Thanks..... ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> Sent: Friday, May 16, 2008 7:26 PM Subject: Re: AeroElectric-List: Avoiding strobe noise? > > > > > > > >So Bob: > > > >as long as all wires are installed and grounded per maunfacture's spec, > >running (stringing) wires like Strobe Power Supply, Nav/Com, Transponder, > >Flaps, Pitot Heat together along the bottom of a fuselage and thru bulkheads > >together are OK ? > > yup . . / > > Bob . . . > > ________________________________________________________________________________
From: "Henry Trzeciakowski" <hammer408(at)comcast.net>
Subject: Re: 6 AWG vs Copper Bar
Date: May 18, 2008
Bob: I have .063 X .50"; can I double up and make 2 bars thus giving me .125 x .50" Thanks ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> Sent: Friday, May 16, 2008 7:25 PM Subject: Re: AeroElectric-List: Re: 6 AWG vs Copper Bar > > > > > > > >Bob: > > > >Insteard of using 6 AWG from starter contctor to Current Limiter, I want to > >use .063 copper bar...is that adequate or should I use .125. > > > >thanks > > .063 x .75" copper is fine. > > Bob . . . > > ________________________________________________________________________________
From: "Ron Brown" <romott@mi-connection.com>
Subject: Re: Getting Off Topic, Was: Schematic Review
Date: May 18, 2008
Scott, An excellent set of rules for Light IFR for the recreational (non-commercial) flyer! I have been flying my Velocity for the past 5 years with very much the same rules. It has allowed me to get out before the low level fog burns off, out of Hilton Head and Florida before the marine layer burns off, and into airports that have a broken or solid layer above them but a 1500 - 2000' ceiling. I also flew single pilot IFR to Oshkosh in between layers at 8000' but with plenty of good ceilings below the underlying layer. It gives me tremendous flexibility that I didn't have when I was trying to scud run and didn't have my instrument rating - downright dangerous!!!! Getting your instrument rating and using your "Light IFR Rules" is VERY HIGHLY RECOMMENDED if you are going to be flying much cross country. Ronnie Brown ________________________________________________________________________________
Subject: Re: Schematic Review
From: "user9253" <fran5sew(at)banyanol.com>
Date: May 18, 2008
Suggestion 1. An avionics master switch is controversial because it becomes a single point failure for all of your avionics. Modern avionics are not supposed to be affected by voltage spikes. If concerned about expensive avionics, one could shut off individual units, not as convenient as a master switch but safer. If you must have an avionics master, consider using a double pole switch wired in parallel. If one half of the switch fails, the other half will carry the load. Suggestion 2. Feed the Aux Battery Avionics Master Switch directly from the battery without going through the Aux Battery Master Switch. Having two switches in series doubles the chances of switch failure. Re-label the Aux Bat Avionics Master switch as "Avionics Aux Feed". Suggestion 3. Remove the ground wire from terminal 4 of the Aux Battery Master Switch. Instead, connect terminal 4 to terminal 2 of the Main Master switch. This essentially connects the two battery contactors in parallel for normal operation. Re-label the Aux Bat Master switch to Aux Bat Isolate. This switch would be normally closed, even after engine shut down. You would only open this switch in case of an emergency. This wiring change will simplify your system. There will be only one master switch to deal with. There will be more cranking amps available. And the aux battery will be kept fully charged. Suggestion 4. Mount and wire the "Avionics Aux Feed" and "Aux Bat Isolate" switches so that they are normally in the down position. They would be toggled up in case of an emergency. Suggestion 5. How about using a variation of Bob Nuckolls' Z-19? I like the feature of the low voltage module automatically isolating the aux battery without pilot intervention. These are only suggestions to help and are not meant to criticize. Joe Gores -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=183666#183666 ________________________________________________________________________________
From: "bob noffs" <icubob(at)newnorth.net>
Subject: battery tenders
Date: May 18, 2008
since battery tenders have become popular the last few years i acquired 1/2 dz from harbor frt. they were 3-5 $ each and seem to work well. snowmobile, atv, skidsteer, motorcycle, etc have never had a low battery since. output varied, so much that i would take a voltmeter along to test units before they went in my shopping cart. one unit put out too much voltage and i lowered it with a diode. it keeps the battery at 13.7-13.8 volts now. is the diode inhibiting any function of the tender to regulate current supplied to the battery? does a $5 unit even have the brains to regulate anything? thanks for any input bob noffs ________________________________________________________________________________
Date: May 18, 2008
From: Gilles Thesee <Gilles.Thesee@ac-grenoble.fr>
Subject: Help for English translation
Hi all, One of my buddies is trying to convince French civil aviation authorities (DGAC) to let him install an Odyssey EFIS in his kitplane project. He is asking for help from naturally English speakers to correct his English translation of the DGAC relevant document. Would any of you gentlemen and ladies care to help correcting the following document for understandable English ? http://contrails.free.fr/translate.php Any inputs appreciated, Thanks in advance, Best regards, -- Gilles http://contrails.free.fr ________________________________________________________________________________
Date: May 18, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: battery tenders
>since battery tenders have become popular the last few years i acquired >1/2 dz from harbor frt. they were 3-5 $ each and seem to work well. >snowmobile, atv, skidsteer, motorcycle, etc have never had a low battery >since. output varied, so much that i would take a voltmeter along to test >units before they went in my shopping cart. one unit put out too much >voltage and i lowered it with a diode. it keeps the battery at 13.7-13.8 >volts now. is the diode inhibiting any function of the tender to regulate >current supplied to the battery? does a $5 unit even have the brains to >regulate anything? > thanks for any input Can't tell without tearing it open and also running tests to deduce performance. What we want to see from a true "tender" is a recharge curve with a behavior like this: http://www.aeroelectric.com/Pictures/Curves/Battery_Tender_Recharge.pdf Note the top-off dwell during the interval before it drops to the "tending" mode. There are some semi-smart chargers like: http://www.aeroelectric.com/Pictures/Curves/Battery_Minder_Recharge.pdf That don't have a top-off dwell. Further, the voltage at which full-charge is expected is somewhat shy of optimal. I've purchased only one Battery Minder and pitched it after seeing the tests. I have a three or four Battery Tenders in the stable of battery maintenance tools along with a number of Schumacher products. About the best bargain I've seen so far is the Schumacher WM-1562A charger often offered by Wallmart and others. It has a very intelligent recharge profile . . . http://www.aeroelectric.com/Pictures/Curves/schumacher_3.jpg . . . and sells for under $20. Schumacher builds some larger, equally sophisticated devices at attractive prices . . . http://www.aeroelectric.com/Pictures/Curves/schumacher_5.jpg I failed to write down the charger I was evaluating here but I think it was a middle-sized device and probably sold for under $60. Unless you have the equipment to grab plots like these it's sort a pig-in-a-poke deal. At first blush, I'd guess that the $5 H.F. devices behave more like the Battery Minder and while much better than a trickle charger (no smarts at all) it fall far short of the best we know how to do for just a few dollars more. Just went to the H.F. website and got pictures and stock numbers on their current offerings. I posted them at: http://www.aeroelectric.com/Pictures/Battery_Chargers/HF_Chargers/ I'm guessing that the charger you're asking about is one of these two: http://www.aeroelectric.com/Pictures/Battery_Chargers/HF_Chargers/42292.gif http://www.aeroelectric.com/Pictures/Battery_Chargers/HF_Chargers/Junk_1.jpg There's another interesting one . . . http://www.aeroelectric.com/Pictures/Battery_Chargers/HF_Chargers/93258.gif designed to mount permanently in the vehicle where a battery is to be maintained. I've already looked at the Junker . . . next time I'm in the store, I'll pick up copies of the other small chargers and test them. I note further that H.F. is offering Schumacher products as well as their own. Everything we've been talking about sells for under $70 with some devices in the $18 range. Short answer is that anything with Schumacher's name on it is a pretty good bet. The other devices may offer good value and performance too . . . but you don't know without testing. Which H.F. stock number device are you wondering about? Bob . . . ________________________________________________________________________________
Date: May 18, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: 6 AWG vs Copper Bar
> > >Bob: > >I have .063 X .50"; can I double up and make 2 bars thus giving me .125 x >.50" Sure . . . but the .50" width doesn't leave you much edge margin at the clearance holes for 5/16" studs and there's some concern for spreading the high currents across the hole through 3/32" connections at the edges. But lots of folk have used this width of material and I've not heard of any problems. In fact, a single layer offers a cross- section of .063 x .50 = .031 square inches. 4AWG wire is two, 3AWG-doubling steps larger than 10AWG. 10 AWG is .1" diameter or 3.14 x .05^2 = 0.0078 square inches. Taken times 4 yields .031 square inches for 4AWG wire. The same as your proposed straps which will cool better because of larger surface area and heat-sinks at the studs. So electrically and thermally, the proposed strips are fine. How about this? Go to your local well-stocked hardware store and get some 5/16" brass washers. Solder to one side of your 0.5" copper strap at the 5/16" hole locations. I think you said you were working with a shunt at the other end which is a 1/4" stud. No "reinforcement" necessary. "Doubling up" the strap makes it more difficult to get the two pieces to lay together. A soldered on doubler at the 5/16" holes is easier and will look better when you're finished. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
From: "Henry Trzeciakowski" <hammer408(at)comcast.net>
Subject: Re: 6 AWG vs Copper Bar
Date: May 18, 2008
Thanks Bob: I like the idea of soldering brass washers.....or better yet, I may just order .063 x .75" wide copper bar and KISS. ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> Sent: Sunday, May 18, 2008 11:15 AM Subject: Re: AeroElectric-List: Re: 6 AWG vs Copper Bar > > > > > > > >Bob: > > > >I have .063 X .50"; can I double up and make 2 bars thus giving me .125 x > >.50" > > Sure . . . but the .50" width doesn't leave you much edge > margin at the clearance holes for 5/16" studs and there's some > concern for spreading the high currents across the hole > through 3/32" connections at the edges. But lots of folk > have used this width of material and I've not heard of > any problems. In fact, a single layer offers a cross- > section of .063 x .50 = .031 square inches. 4AWG > wire is two, 3AWG-doubling steps larger than 10AWG. > 10 AWG is .1" diameter or 3.14 x .05^2 = 0.0078 > square inches. Taken times 4 yields .031 square > inches for 4AWG wire. The same as your proposed > straps which will cool better because of larger > surface area and heat-sinks at the studs. > > So electrically and thermally, the proposed strips > are fine. How about this? Go to your local well-stocked > hardware store and get some 5/16" brass washers. > Solder to one side of your 0.5" copper strap at the > 5/16" hole locations. I think you said you were > working with a shunt at the other end which is a > 1/4" stud. No "reinforcement" necessary. > > "Doubling up" the strap makes it more difficult > to get the two pieces to lay together. A soldered > on doubler at the 5/16" holes is easier and will > look better when you're finished. > > Bob . . . > > ----------------------------------------) > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > ---------------------------------------- > > ________________________________________________________________________________
From: "Henry Trzeciakowski" <hammer408(at)comcast.net>
Subject: Re: S704-1 Relay Question
Date: May 18, 2008
Bob: I'm going to install a "Heavy E-bus and use your architecture: Bat-bus (14AWG) to 704-1 relay with S700-1-3(22AWG) switch coming off relay and 14 awg from relay to e-bus. I'm a little confused on how the Relay is wired. I've printed the wiring picture of the Relay off the aeroelectric website and it didn't help. The diode, via fastabs is wired or jumps the - to + terminal and there are also 2 wires crimped to the same fasttabs. I'm assuming the black goes to ground, but where does the one wired to the + terminal go to ?? Also where does the "COM" wire and N.O. wire go? OR...keeping the question simple ---how do you wire the Relay utilizing Heavy E-Bus architecture? Thanks ________________________________________________________________________________
Date: May 18, 2008
From: "Ron Quillin" <rjquillin(at)gmail.com>
Subject: Re: battery tenders
>From some research I have done in the past couple of years, I've noted Concorde has gotten touchy regarding maximum charge voltage in maintenance or float mode. They assert some units have been applying an excessive, for the ambient temperature, voltage and this has caused a decrease in service life of their AGM type batteries. BatteryMINDer, and perhaps others, have responded by including sensors to adjust float voltage for ambient temperature (it needs to increase with decreasing temperature) even to the point of recalling some of their non compensating units. I suppose one could argue this is just a marketing ploy to sell more chargers, but they are, or at least were, offering replacement units at a 50% discount. Battery details can be found at http://www.concordebattery.com/otherpdf/ownermanual.pdf on page 16. Ron Q. On Sun, May 18, 2008 at 10:55 AM, Robert L. Nuckolls, III wrote: > > > >> since battery tenders have become popular the last few years i acquired >> 1/2 dz from harbor frt. they were 3-5 $ each and seem to work well. >> does a $5 unit even have the brains to >> regulate anything? >> thanks for any input > > Can't tell without tearing it open and also > running tests to deduce performance. What we > want to see from a true "tender" is a recharge > curve with a behavior like this: > > That don't have a top-off dwell. Further, the voltage > at which full-charge is expected is somewhat shy > of optimal. I've purchased only one Battery Minder > and pitched it after seeing the tests. I have a > three or four Battery Tenders in the stable of > battery maintenance tools along with a number of > Schumacher products. > > About the best bargain I've seen so far is the > Schumacher WM-1562A charger often offered by > Wallmart and others. It has a very intelligent > recharge profile . . . > > Short answer is that anything with Schumacher's > name on it is a pretty good bet. The other devices > may offer good value and performance too . . . but > you don't know without testing. Which H.F. stock > number device are you wondering about? > > Bob . . . ________________________________________________________________________________
From: "bob noffs" <icubob(at)newnorth.net>
Subject: battery tenders
Date: May 18, 2008
hi bob, the h.f. unit i am talking about is the #42292. appreciate your input. bob noffs ________________________________________________________________________________
Subject: Re: Use of 700-2-10 switch for Voltage Sense - how
to wire?
From: "mikef" <mikefapex(at)gmail.com>
Date: May 18, 2008
I obtained both the Digikey and B&C 2-7 switches. When wired as indicated on the diagram the Digikey version worked as expected. However the B&C 2-7 did not. The middle position does not show the expected voltage (or any voltage). When I substitute a 2-10 switch it, like the Digikey version, works as expected. I will play further with the B&C 2-7 but it is either not designed for wiring that way or just a bad switch. Mike Read this topic online here: http://forums.matronics.com/viewtopic.php?p=183735#183735 ________________________________________________________________________________
Date: May 18, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Use of 700-2-10 switch for Voltage Sense
- how to wire? > >I obtained both the Digikey and B&C 2-7 switches. > >When wired as indicated on the diagram the Digikey version worked as >expected. However the B&C 2-7 did not. The middle position does not show >the expected voltage (or any voltage). When I substitute a 2-10 switch it, >like the Digikey version, works as expected. > >I will play further with the B&C 2-7 but it is either not designed for >wiring that way or just a bad switch. You lost me. Did our conversation start out talking about the 2-7 functionality? A 2-7 is double pole, three position, (ON)-OFF-(ON) device where the parens around the 'ON' denotes a spring-loaded momentary position. The 2-10 is a double pole, three position, PROGRESSIVE TRANSFER, ON-ON-ON device that is stable at all three positions. No spring loading. A few of the ways these two switches can be used are illustrated in: http://aeroelectric.com/Pictures/Schematics/2-Pole_Switch_Options.pdf and in Figure 11-14 in the 'Connection. The 2-7 cannot substitute for a 2-10. A 2-70 (progressive transfer version of a 2-7) can do the same switching job as a 2-10 where you WANT the two extreme positions to be momentary. I don't think B&C stocks the 2-70 so if you got a 2-7 from them, I would predict mystifying results. The Digikey number I gave you was for a 2-70 equivalent in a miniature switch by C&K . . . not a 2-10. If you've already drilled a hole for a standard size 2-70, there's a version of the miniature 2-70 that sports a standard size toggle and mounting hole. See: http://aeroelectric.com/Pictures/Switches/7215TZQE.jpg and http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=CKN1495-ND Bob . . . ________________________________________________________________________________
Date: May 18, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: battery tenders
>hi bob, > the h.f. unit i am talking about is the #42292. appreciate your input. > > bob noffs Okay. I'll pick one up and test it. Bob . . . Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: May 18, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: battery tenders
> > >From some research I have done in the past couple of years, I've noted >Concorde has gotten touchy regarding maximum charge voltage in >maintenance or float mode. They assert some units have been applying >an excessive, for the ambient temperature, voltage and this has caused >a decrease in service life of their AGM type batteries. Has this shown up in print anywhere? I mean something that illustrates Concord's increasing tension? >BatteryMINDer, and perhaps others, have responded by including sensors >to adjust float voltage for ambient temperature (it needs to increase >with decreasing temperature) even to the point of recalling some of >their non compensating units. I suppose one could argue this is just >a marketing ploy to sell more chargers, but they are, or at least >were, offering replacement units at a 50% discount. Battery details >can be found at >http://www.concordebattery.com/otherpdf/ownermanual.pdf >on page 16. This document hasn't been changed with respect to charging recommendations for many moons. You can go to . . . http://aeroelectric.com/Mfgr_Data.html and get the Concorde battery poop I've posted on website. The maintenance data speaks to fast-charging situations and the techniques are essentially the same for both flooded and AGM batteries . . . including the recommended BUS voltages versus for in-flight recharging. None of this data is particularly relevant to a smart battery maintainer which spends only a limited amount of time in the top-off mode before dropping to a sustain level that is not even mentioned in the Concorde data. Any words from the manufacturers of battery maintainers as to the "tailoring" of their product to the "special needs" of an AGM battery is mostly marketing hype. However the device tops a battery off is not terribly relevant to battery life . . . the event lasts but a few hours at modest current levels compared to the comparatively much larger abuse the battery receives while being replenished by a 60A alternator! As long as the maintainer drops to a true maintenance level (hundreds of millivolts above the battery's open circuit voltage) then the battery is not at-risk for abuse from the maintainer. That temperature compensating stuff doesn't hurt but don't spend a lot of money on it cause it doesn't make that much difference in battery service life. Bob . . . ________________________________________________________________________________
Date: May 18, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: S704-1 Relay Question
> > >Bob: > >I'm going to install a "Heavy E-bus and use your architecture: Bat-bus >(14AWG) to 704-1 relay with S700-1-3(22AWG) switch coming off relay and 14 >awg from relay to e-bus. I'm a little confused on how the Relay is wired. >I've printed the wiring picture of the Relay off the aeroelectric website >and it didn't help. > >The diode, via fastabs is wired or jumps the - to + terminal and there are >also 2 wires crimped to the same fasttabs. I'm assuming the black goes to >ground, but where does the one wired to the + terminal go to ?? > >Also where does the "COM" wire and N.O. wire go? > >OR...keeping the question simple ---how do you wire the Relay utilizing >Heavy E-Bus architecture? > >Thanks As shown in http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z32K.pdf The picture at: http://aeroelectric.com/Pictures/Relays/s704inst.jpg shows how to get the diode leads into the same terminals with the wires that go to ends of the relay coil . . . but according to Z32K you'll need to drop two wires into the COM terminal too. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: May 19, 2008
From: Ken <klehman(at)albedo.net>
Subject: Re: Schematic Review
I am skeptical whether paralleling a double pole switch really helps reliability. Mechanical switch failure would take out both poles. A lightly loaded switch might suffer corrosion and wear issues at a similar rate for both poles. One would not know if one pole failed prematurely. For heavily loaded contacts perhaps the second pole would help share the arc damage though?? Ken user9253 wrote: > > Suggestion 1. An avionics master switch is controversial because it becomes a single point failure for all of your avionics. Modern avionics are not supposed to be affected by voltage spikes. If concerned about expensive avionics, one could shut off individual units, not as convenient as a master switch but safer. If you must have an avionics master, consider using a double pole switch wired in parallel. If one half of the switch fails, the other half will carry the load. > ________________________________________________________________________________
From: "Andrew Butler" <andrewbutler(at)ireland.com>
Date: May 19, 2008
Subject: Re: S704-1 Relay Question
Hello, At what level of load does an E-Bus become "heavy duty"? Also, what is the purpose of the diode? I know what a diode does, but what is its practical use in this instance? Cheers, Andrew. ----- Original Message ----- From: "Robert L. Nuckolls, III" To: aeroelectric-list(at)matronics.com Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Date: Sun, 18 May 2008 22:31:42 -0500 > > Bob: > > I'm going to install a "Heavy E-bus and use your architecture: Bat-bus > (14AWG) to 704-1 relay with S700-1-3(22AWG) switch coming off relay and 14 > awg from relay to e-bus. I'm a little confused on how the Relay is wired. > I've printed the wiring picture of the Relay off the aeroelectric website > and it didn't help. > > The diode, via fastabs is wired or jumps the - to + terminal and there are > also 2 wires crimped to the same fasttabs. I'm assuming the black goes to > ground, but where does the one wired to the + terminal go to ?? > > Also where does the "COM" wire and N.O. wire go? > > OR...keeping the question simple ---how do you wire the Relay utilizing > Heavy E-Bus architecture? > > Thanks As shown in http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z32K.pdf The picture at: http://aeroelectric.com/Pictures/Relays/s704inst.jpg shows how to get the diode leads into the same terminals with the wires that go to ends of the relay coil . . . but according to Z32K you'll need to drop two wires into the COM terminal too. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- =========== =========== =========== =========== ________________________________________________________________________________
Date: May 19, 2008
From: "Ron Shannon" <rshannon(at)CRUZCOM.COM>
Subject: Re: S704-1 Relay Question
On Mon, May 19, 2008 at 6:11 AM, Andrew Butler wrote: > Hello, > > At what level of load does an E-Bus become "heavy duty"? > > Also, what is the purpose of the diode? I know what a diode does, but what > is its practical use in this instance? > > Cheers, > > Andrew. > The level at which an E-bus becomes "heavy duty" is not a precise point, but certainly occurs when the E-bus is expected to carry loads that would strain or exceed limits for a standalone toggle switch. Although the S700 series switches are rated to 15A, you should probably be seriously considering a separate relay whenever load approaches 10A, IMHO. The diode keeps the E-bus from back feeding the Main bus when the E-bus alternate feed (direct from battery or battery bus) is ON. If the E-bus were allowed to back feed the Main bus, it would defeat the purpose of the E-bus, which is rapid, positive reduction of load upon alternator failure. Use of a diode instead of another switch eliminates the need to flip another switch (i.e., reduces chance for error, also, see "heavy duty" discussion above). Ron ________________________________________________________________________________
From: "Andrew Butler" <andrewbutler(at)ireland.com>
Date: May 19, 2008
Subject: Re: S704-1 Relay Question
Thanks Ron, though the diode I was referring is the 1N4001 across the coil of the S704 relay. There is something I don't know, cause I don't see it adding any functionality....... Andrew. ----- Original Message ----- From: "Ron Shannon" To: aeroelectric-list(at)matronics.com Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Date: Mon, 19 May 2008 07:07:20 -0700 On Mon, May 19, 2008 at 6:11 AM, Andrew Butler wrote: Hello, At what level of load does an E-Bus become "heavy duty"? Also, what is the purpose of the diode? I know what a diode does, but what is its practical use in this instance? Cheers, Andrew. The level at which an E-bus becomes "heavy duty" is not a precise point, but certainly occurs when the E-bus is expected to carry loads that would strain or exceed limits for a standalone toggle switch. Although the S700 series switches are rated to 15A, you should probably be seriously considering a separate relay whenever load approaches 10A, IMHO. The diode keeps the E-bus from back feeding the Main bus when the E-bus alternate feed (direct from battery or battery bus) is ON. If the E-bus were allowed to back feed the Main bus, it would defeat the purpose of the E-bus, which is rapid, positive reduction of load upon alternator failure. Use of a diode instead of another switch eliminates the need to flip another switch (i.e., reduces chance for error, also, see "heavy duty" discussion above). Ron =========== ======== === ________________________________________________________________________________
Subject: Re: Schematic Review
From: "user9253" <fran5sew(at)banyanol.com>
Date: May 19, 2008
Hi Ken, I agree with you that a mechanical failure will disable both poles of a double pole switch. It has been my experience that the majority of switches fail because of high resistance between contacts, especially in switches that are not used frequently. I also agree that one would not know if only one pole failed. But who cares as long as the load keeps working? I am not suggesting that double pole switches be used in place of every single pole switch, only for essential applications. The added cost and weight for a couple of DPST switches is not much. Depending on one's panel, it could be a hassle replacing a switch. I would want to delay doing that by using a more reliable switch. I believe that a double pole switch wired in parallel has an extended life compared to a single pole switch. Maybe someone has already done tests to prove or disprove this theory. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=183819#183819 ________________________________________________________________________________
Subject: Re: Use of 700-2-10 switch for Voltage Sense - how
to wire?
From: "mikef" <mikefapex(at)gmail.com>
Date: May 19, 2008
Bob, My bad, I mixed up the switch types. I think I will stick with the small Digikey switch and be happy. Thanks again, Mike Read this topic online here: http://forums.matronics.com/viewtopic.php?p=183822#183822 ________________________________________________________________________________
Date: May 19, 2008
From: "Etienne Phillips" <etienne.phillips(at)gmail.com>
Subject: Re: S704-1 Relay Question
It's called a fly-back diode. The coil of a relay is a fairly sizeable inductor, which means that a step-change in current is not really possible. What happens when the current to the coil is removed, the "inertia" of the inductor will force a current to continue flowing for a short while, generating large voltages and arcing across switch contacts. The fly-back diode gives this current a path to flow without interfering with the rest of the electrical system, and only comes into play when the coil is de-energized. For more info, go to http://en.wikipedia.org/wiki/Flyback_diode :-) Etienne 2008/5/19 Andrew Butler : > Thanks Ron, though the diode I was referring is the 1N4001 across the coil > of the S704 relay. There is something I don't know, cause I don't see it > adding any functionality....... > > Andrew. > > ----- Original Message ----- > From: "Ron Shannon" > To: aeroelectric-list(at)matronics.com > Subject: Re: AeroElectric-List: Re: S704-1 Relay Question > Date: Mon, 19 May 2008 07:07:20 -0700 > > On Mon, May 19, 2008 at 6:11 AM, Andrew Butler > wrote: > >> Hello, >> >> At what level of load does an E-Bus become "heavy duty"? >> >> Also, what is the purpose of the diode? I know what a diode does, but what >> is its practical use in this instance? >> >> Cheers, >> >> Andrew. >> > > > The level at which an E-bus becomes "heavy duty" is not a precise point, > but certainly occurs when the E-bus is expected to carry loads that would > strain or exceed limits for a standalone toggle switch. Although the S700 > series switches are rated to 15A, you should probably be seriously > considering a separate relay whenever load approaches 10A, IMHO. > > The diode keeps the E-bus from back feeding the Main bus when the E-bus > alternate feed (direct from battery or battery bus) is ON. If the E-bus were > allowed to back feed the Main bus, it would defeat the purpose of the E-bus, > which is rapid, positive reduction of load upon alternator failure. Use of a > diode instead of another switch eliminates the need to flip another switch > (i.e., reduces chance for error, also, see "heavy duty" discussion above). > > Ron > > * > > ist">http://www.matronics.com/Navigator?AeroElectric-Listics.com > .matronics.com/contribution > * > > > * > > * > > ________________________________________________________________________________
Date: May 19, 2008
From: "Ron Shannon" <rshannon(at)CRUZCOM.COM>
Subject: Re: S704-1 Relay Question
On Mon, May 19, 2008 at 8:16 AM, Andrew Butler wrote: > Thanks Ron, though the diode I was referring is the 1N4001 across the coil > of the S704 relay. There is something I don't know, cause I don't see it > adding any functionality....... > > Andrew. > Ooops! So much for unwarranted assumptions. As for the diode across the coil, see http://www.aeroelectric.com/articles/spikecatcher.pdf Ron ________________________________________________________________________________
From: "Andrew Butler" <andrewbutler(at)ireland.com>
Date: May 19, 2008
Subject: Re: S704-1 Relay Question
Perfect! Thanks. ----- Original Message ----- From: "Ron Shannon" To: aeroelectric-list(at)matronics.com Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Date: Mon, 19 May 2008 08:43:42 -0700 On Mon, May 19, 2008 at 8:16 AM, Andrew Butler wrote: Thanks Ron, though the diode I was referring is the 1N4001 across the coil of the S704 relay. There is something I don't know, cause I don't see it adding any functionality....... Andrew. Ooops! So much for unwarranted assumptions. As for the diode across the coil, see http://www.aeroelectric.com/articles/spikecatcher.pdf Ron =========== ======== === ________________________________________________________________________________
Date: May 19, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: S704-1 Relay Question
>Hello, > >At what level of load does an E-Bus become "heavy duty"? The e-bus was born of a time when many if not most builders could plan on and implement an endurance load of 5A or less. The rule-of-thumb for maximum protection level of an always hot wire in TC aircraft is 5A . . . so the idea of taking a 5A fused feeder off the battery bus to supply an e-bus through a panel mounted switch was well within the parameters of accepted practice in TC aircraft. As folks piled more stuff on the e-bus, 5A feeders wouldn't cut it any more so it became a tribute to accepted practice to add a mini battery contactor at the battery bus to provide a local control point for the e-bus alternate feed path. From a reliability perspective I really like the idea of staying with a toggle switch. Further, given that a 7A fuse is on the order of 5-10 times faster than a 5A breaker, it seems a reasonable tribute to accepted practice to say that anything over a 7A FUSED alternate feed path is "heavy duty" and justifies the complexity of an additional relay. 7A or less can be handled with a toggle switch. Bob . . . ________________________________________________________________________________
Date: May 19, 2008
From: Gilles Thesee <Gilles.Thesee@ac-grenoble.fr>
Subject: Re: Help for English translation
Mickey Coggins a crit : > > > Hi Gilles, > > There is a MGL representative in France - perhaps he has already > contacted the DGAC. > > http://www.stratomaster.eu/ > > If the document you need translated is going to the boys in South > Africa, I'd say it is quite understandable. To make sure the > translation is accurate, it would help to have a link to the French > version. > Mickey and all, Thanks to all who responded, on-list and off-list. I added a link to the original French version at the bottom of the page http://contrails.free.fr/translate.php I understand that the translation is for the use of the French MGL representative. Thanks again, Best regards, -- Gilles http://contrails.free.fr ________________________________________________________________________________
Date: May 19, 2008
From: skyking135 <skyking135(at)bellsouth.net>
Subject: Re: battery tenders
I have one of the 42292 units and measured the output voltage on my particular unit to be around 12.7 volts, noload. It was only getting the battery up to about 12.3 volts; not enough to keep a good charge on a battery. So, being the curious one that I am, I popped open the cover to see if I could figure out how to adjust the output voltage. I found a spot on the circuit board for a varistor (VR1) that had a 55ohm resistor soldered in that postion. I figured that must adjust the output voltage. I simply replaced the 55ohm resistor with a 22ohm one I had on hand. That boosted the ouptut to a more respectable 13.2 volts. It still will only charge up to about 12.9 volts which is better than the 12.3 is was reaching before. I think I will adjust the resistor again to see if I can squeeze out a little more performance. Quality control is not high on the list of priorities with Harbor Freight. You get what you pay for. db ________________________________________________________________________________
From: "Dave Leikam" <daveleikam(at)wi.rr.com>
Subject: Re: Schematic Review
Date: May 19, 2008
I flew an Archer for a few years that had two avionics masters side by side wired parallel. Toggles will usually fail when turned on or off. If one failed (never did), you knew it and the other was available. Dave Leikam #40496 N89DA (Reserved) Muskego, WI ----- Original Message ----- From: "Ken" <klehman(at)albedo.net> Sent: Monday, May 19, 2008 7:30 AM Subject: Re: AeroElectric-List: Re: Schematic Review > > I am skeptical whether paralleling a double pole switch really helps > reliability. Mechanical switch failure would take out both poles. A > lightly loaded switch might suffer corrosion and wear issues at a similar > rate for both poles. One would not know if one pole failed prematurely. > For heavily loaded contacts perhaps the second pole would help share the > arc damage though?? > Ken > > user9253 wrote: >> >> >> Suggestion 1. An avionics master switch is controversial because it >> becomes a single point failure for all of your avionics. Modern avionics >> are not supposed to be affected by voltage spikes. If concerned about >> expensive avionics, one could shut off individual units, not as >> convenient as a master switch but safer. If you must have an avionics >> master, consider using a double pole switch wired in parallel. If one >> half of the switch fails, the other half will carry the load. >> > > > ________________________________________________________________________________
From: Kevin Horton <khorton01(at)rogers.com>
Subject: Re: Help for English translation
Date: May 19, 2008
On 19 May 2008, at 17:25, Gilles Thesee wrote: > <Gilles.Thesee@ac-grenoble.fr> > > Mickey Coggins a crit : >> matronics(at)rv8.ch> >> >> Hi Gilles, >> >> There is a MGL representative in France - perhaps he has already >> contacted the DGAC. >> >> http://www.stratomaster.eu/ >> >> If the document you need translated is going to the boys in South >> Africa, I'd say it is quite understandable. To make sure the >> translation is accurate, it would help to have a link to the >> French version. >> > > Mickey and all, > > Thanks to all who responded, on-list and off-list. > I added a link to the original French version at the bottom of the > page > http://contrails.free.fr/translate.php > > I understand that the translation is for the use of the French MGL > representative. > Many elements of these requirements appear to be lifted directly from CS 23, the European equivalent to FAR 23. You can find the accepted English wording for some sections by looking at FAR 23.1301, 23.1309, 23.1311, 23.1322, etc. Available on the FAA web site. -- Kevin Horton RV-8 (FInal Assembly) Ottawa, Canada http://www.kilohotel.com/rv8 ________________________________________________________________________________
From: "earl_schroeder(at)juno.com" <earl_schroeder(at)juno.com>
Date: May 20, 2008
Subject: Re: battery tenders
Hi db, The older 42292 [or whatever (the previous generation)]did have a variable resister on the circuit board. Nearly every one needed some adjustment as I have a dozen or so. I purchased a minimum order of 100 ohm pots to install in the newer units. I adjust them for 13.8 open circuit. I've repaired six or so [mine and others] as the common failure is the transformer wire disconnects where it attaches to the plug that plugs into the 110VAC. A sharp knife will separate the plastic housing around the transformer providing access. I thought originally that trying to start an engine with the unit connected would melt the solder at that joint but I'm not sure. For the money they are hard to beat but as some say, you get what you pay for.. Earl -- skyking135 wrote: < I have one of the 42292 units and measured the output voltage on my particular unit to be around 12.7 volts, noload. It was only getting the battery up to about 12.3 volts; not enough to keep a good charge on a battery. So, being the curious one that I am, I popped open the cover to see if I could figure out how to adjust the output voltage. I found a spot on the circuit board for a varistor (VR1) that had a 55ohm resistor soldered in that postion. I figured that must adjust the output voltage. I simply replaced the 55ohm resistor with a 22ohm one I had on hand. That boosted the ouptut to a more respectable 13.2 volts. It still will only charge up to about 12.9 volts which is better than the 12.3 is was reaching before. I think I will adjust the resistor again to see if I can squeeze out a little more performance. Quality control is not high on the list of priorities with Harbor Freight. You get what you pay for. db ________________________________________________________________________________
Date: May 19, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Any legacy regulator gurus out there?
I received some pictures from a reader who is looking for an adjustment procedure for a Delco-Remy generator regulator. http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_4.jpg http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_3.jpg http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_2.jpg http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_1.jpg I've never seen an electro-mechanical regulator that was this sophisticated. It appears to have airgap adjustments as well as spring tension adjustments for both the V-reg and I-lim relays. I'm wondering if anyone on this IS or KNOWS someone WHO IS familiar adjustment of these devices. I'm afraid that the "offical" procedure will require test equipment common to a generator/regulator overhaul shop. Unless I can find data specific to this device (I think the 12VN7E numbers on the base plate are a part number) I'm going to recommend that he not mess with anything other than the tension spring on the voltage regulator which can be adjusted with the engine running and a light load on the system. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: May 19, 2008
From: Les Kearney <kearney(at)shaw.ca>
Subject: Contactor Locations
Hi I am trying to plan my RV10 electrical system and have a question for the electrical mavens. That is, how far from avionics should battery contactors be? I am looking at mounting my batteries in the sub panel area and would like to co-locate the contactors in the same area. Access is not an issue but I am concerned about possible interference with the avionics. I may end up locating the starter contactor on the same area as well. Would this be a problem? Cheers Les Kearney ________________________________________________________________________________
From: "Andrew Butler" <andrewbutler(at)ireland.com>
Date: May 20, 2008
Subject: Re: S704-1 Relay Question
Okay, I've read the Wikipedia and aeroelectric articles. So far so good. So, in the absence of the diode, where is the "arc" likely to occur? If I have understood correctly I'm saying at the E-BUS feed switch rather than at the switch in the relay. Am I correct? If not, why does the arc occur at the relay switch and not the feed switch. It has to do with the current flow path......... Thanks for your help. Andrew. ----- Original Message ----- From: "Etienne Phillips" To: aeroelectric-list(at)matronics.com Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Date: Mon, 19 May 2008 17:40:15 +0200 It's called a fly-back diode. The coil of a relay is a fairly sizeable inductor, which means that a step-change in current is not really possible. What happens when the current to the coil is removed, the "inertia" of the inductor will force a current to continue flowing for a short while, generating large voltages and arcing across switch contacts. The fly-back diode gives this current a path to flow without interfering with the rest of the electrical system, and only comes into play when the coil is de-energized. For more info, go to http://en.wikipedia.org/wiki/Flyback_diode :-) Etienne 2008/5/19 Andrew Butler : Thanks Ron, though the diode I was referring is the 1N4001 across the coil of the S704 relay. There is something I don't know, cause I don't see it adding any functionality....... Andrew. ----- Original Message ----- From: "Ron Shannon" To: aeroelectric-list(at)matronics.com Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Date: Mon, 19 May 2008 07:07:20 -0700 On Mon, May 19, 2008 at 6:11 AM, Andrew Butler <andrewbutler@ireland. com> wrote: Hello, At what level of load does an E-Bus become "heavy duty"? Also, what is the purpose of the diode? I know what a diode does, but what is its practical use in this instance? Cheers, Andrew. The level at which an E-bus becomes "heavy duty" is not a precise point, but certainly occurs when the E-bus is expected to carry loads that would strain or exceed limits for a standalone toggle switch. Although the S700 series switches are rated to 15A, you should probably be seriously considering a separate relay whenever load approaches 10A, IMHO. The diode keeps the E-bus from back feeding the Main bus when the E-bus alternate feed (direct from battery or battery bus) is ON. If the E-bus were allowed to back feed the Main bus, it would defeat the purpose of the E-bus, which is rapid, positive reduction of load upon alternator failure. Use of a diode instead of another switch eliminates the need to flip another switch (i.e., reduces chance for error, also, see "heavy duty" discussion above). Ron ist"> http://www.matronics.com/Navigator?AeroElectric-List ics.com . matronics.com/contribution =========== ======== === ________________________________________________________________________________
Subject: Re: Any legacy regulator gurus out there?
From: "jetboy" <sanson.r(at)xtra.co.nz>
Date: May 20, 2008
Sir, I dont quite want to claim guru status, working on my previous C150A from '61 it was similar and I did reset the V reg to around 14.4 - it was sitting about 13 - and reset the I reg with a wirewound resistor (one of those old monster types with the sliding clamp) to get the output up to 12 amps or so from the 'as found' 6 amps. It was actually a 20 amp generator but 12 is enough when the professional fix would be 100s of miles and $ away I dont recall whether I altered the gaps or tension for this but I did it after cleaning the contacts from 40 years of pitting with a burnishing tool. Some time later I had a low charge again and discovered the aircraft master switch - which thoughtfully includes cutoff contacts for the generator field line - was in need of similar refurbishing. love these old systems because they are actually repairable - just go to where the smoke last escaped from... Moral of the story for me was I had wrongly assumed I knew enough not to check the aircraft schematics first. In all probability the regulator may have been OK but the worn switch in the field line had reduced the drive. It did no harm checking the regulator and it would have been a shame to have it binned as it looked like new inside just as the ones pictured. So I concur with your notion to have him only mess with the V reg - perhaps after cleaning the contacts and checking the other wiring for hidden resistance. Ralph -------- Ralph - CH701 / 2200a Read this topic online here: http://forums.matronics.com/viewtopic.php?p=183994#183994 ________________________________________________________________________________
From: "bob noffs" <icubob(at)newnorth.net>
Subject: battery tenders
Date: May 20, 2008
earl, a few years ago when battery tenders was a topic here i got started on the h. f. units. i ran into a low voltagw problem. i remember a post back then about the adjustable pots. i opened one up and no adjustable pot. this was probably 2 years ago. that is why i shopped for them with my voltmeter. i dont believe h. f. management will let me take them in the backroom and test them anymore. bob noffs ________________________________________________________________________________
Date: May 20, 2008
From: "Etienne Phillips" <etienne.phillips(at)gmail.com>
Subject: Re: S704-1 Relay Question
That is correct, in the E-bus Alternate Feed Switch in this case, or in a more general case when dealing with inductor-like components, it'll arc across whatever component tries to remove power to the relay. In the case of a solid-state IC, this will normally be the silicon wafer, which would let out the smoke and kill the chip. I know someone who lost a starter switch in his Cozy after about 15 engine starts because the fly-back diode was missing from the starter contactor, that's how marked the effect is... A new switch and one 50c fly-back diode later and no more problems. Hope that helps :-) Etienne 2008/5/20 Andrew Butler : > Okay, I've read the Wikipedia and aeroelectric articles. So far so good. > > So, in the absence of the diode, where is the "arc" likely to occur? If I > have understood correctly I'm saying at the E-BUS feed switch rather than at > the switch in the relay. Am I correct? > > If not, why does the arc occur at the relay switch and not the feed switch. > It has to do with the current flow path......... > > Thanks for your help. > > Andrew. > > ----- Original Message ----- > From: "Etienne Phillips" > To: aeroelectric-list(at)matronics.com > Subject: Re: AeroElectric-List: Re: S704-1 Relay Question > Date: Mon, 19 May 2008 17:40:15 +0200 > > It's called a fly-back diode. > > The coil of a relay is a fairly sizeable inductor, which means that a > step-change in current is not really possible. What happens when the current > to the coil is removed, the "inertia" of the inductor will force a current > to continue flowing for a short while, generating large voltages and arcing > across switch contacts. The fly-back diode gives this current a path to flow > without interfering with the rest of the electrical system, and only comes > into play when the coil is de-energized. > > For more info, go to http://en.wikipedia.org/wiki/Flyback_diode > > :-) > > Etienne > > 2008/5/19 Andrew Butler : > >> Thanks Ron, though the diode I was referring is the 1N4001 across the >> coil of the S704 relay. There is something I don't know, cause I don't see >> it adding any functionality....... >> >> Andrew. >> >> ----- Original Message ----- >> From: "Ron Shannon" >> To: aeroelectric-list(at)matronics.com >> Subject: Re: AeroElectric-List: Re: S704-1 Relay Question >> Date: Mon, 19 May 2008 07:07:20 -0700 >> >> On Mon, May 19, 2008 at 6:11 AM, Andrew Butler >> wrote: >> >>> Hello, >>> >>> At what level of load does an E-Bus become "heavy duty"? >>> >>> Also, what is the purpose of the diode? I know what a diode does, but >>> what is its practical use in this instance? >>> >>> Cheers, >>> >>> Andrew. >>> >> >> >> The level at which an E-bus becomes "heavy duty" is not a precise point, >> but certainly occurs when the E-bus is expected to carry loads that would >> strain or exceed limits for a standalone toggle switch. Although the S700 >> series switches are rated to 15A, you should probably be seriously >> considering a separate relay whenever load approaches 10A, IMHO. >> >> The diode keeps the E-bus from back feeding the Main bus when the E-bus >> alternate feed (direct from battery or battery bus) is ON. If the E-bus were >> allowed to back feed the Main bus, it would defeat the purpose of the E-bus, >> which is rapid, positive reduction of load upon alternator failure. Use of a >> diode instead of another switch eliminates the need to flip another switch >> (i.e., reduces chance for error, also, see "heavy duty" discussion above). >> >> Ron >> >> * >> >> ist">http://www.matronics.com/Navigator?AeroElectric-Listics.com >> .matronics.com/contribution >> * >> >> >> * >> >> * >> >> > * > > ist">http://www.matronics.com/Navigator?AeroElectric-Listics.com > .matronics.com/contribution > * > > > * > > > * > > ________________________________________________________________________________
Date: May 20, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Contactor Locations
>Hi > > >I am trying to plan my RV10 electrical system and have a question for the >electrical mavens. That is, how far from avionics should battery >contactors be? I am looking at mounting my batteries in the sub panel area >and would like to co locate the contactors in the same area. Access is not >an issue but I am concerned about possible interference with the avionics. >I may end up locating the starter contactor on the same area as well. >Would this be a problem? > > >Cheers > > >Les Kearney Contactors are not high level antagonists to other components of the system. You mount contactors where it makes the most sense for their function. Battery contactors close to batteries, starter contactors close to starters, ect. In some architectures, they can be clustered together. In any case, there are no characteristics of a contactor that makes them a threat to anything other than the switch that controls them. See: http://www.aeroelectric.com/articles/spikecatcher.pdf http://www.aeroelectric.com/articles/spike.pdf Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: May 20, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: S704-1 Relay Question
>Okay, I've read the Wikipedia and aeroelectric articles. So far so good. > >So, in the absence of the diode, where is the "arc" likely to occur? If I >have understood correctly I'm saying at the E-BUS feed switch rather than >at the switch in the relay. Am I correct? > >If not, why does the arc occur at the relay switch and not the feed >switch. It has to do with the current flow path......... > >Thanks for your help. > >Andrew. Not sure what you're calling the "feed switch". With respect to contactors and relays, there is potential for effects of field collapse in an inductor to erode the contacts of the device that controls that contactor or relay. Hence, the long standing practice of adding spike suppression across the coils of such devices as illustrated in the Z-figures. Now, ANY time you break a circuit with the opening of hard contacts as in a switch, relay or contactor (that is carrying any amount of current at any voltage) there WILL be an arc formed in spreading gap between opening contacts. There was a school of thought circulated in the OBAM aircraft community a few years ago that for voltages and/or currents below some low level (I don't recall the numbers now) that no arcing would occur. So as an experiment, I took a miniature switch and sanded out the side of it like this: http://aeroelectric.com/Pictures/Switches/sm_switch_cutaway.jpg I fixtured it under the microscope and caused the NO contacts to carry 1 or 1/2 amp of current at 1.5 volts (alkaline d-cell). In a dark room I could clearly observe a tiny but bright blue arc in the spreading gap between the contacts when the circuit was broken. THIS ARCING IS NOT the phenomenon of concern with respect to noise or debilitating effects on controlling or controlled devices. Hence we rarely see arc suppression techniques applied to these effects. One exception is the quest for achieving the Beech Aircraft ov relay trip-life using relays some 30+ years ago as described in the chapter on OV Protection in the 'Connection. There is also a school of thought that suggests plain vanilla diodes across relay and contactor coils will cause a slowing of contact spreading velocity and is therefore an inducement to prolonged arcing at the opening contacts. Experiments on my bench showed that while adding a diode did indeed cause a DELAY IN OPENING of the contacts . . . http://www.aeroelectric.com/Pictures/Curves/704-1DelayNoDiode.gif http://www.aeroelectric.com/Pictures/Curves/704-1DelayWithDiode.gif . . . use of the plain vanilla diode produced no significant slowing of contact spreading velocity once they started to move. http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeWithDiode.gif In any case, the arcing produced either at controlling switches -OR- contacts of the controlled devices IS NOT a widespread threat for damage to other components in the system. The strongest effect you'll experience from the behavior of an unsuppressed relay or contactor coil is a transient interference event. A few years ago I helped a builder track down why opening his avionics bus relay on an off-the-shelf integrated power distribution system caused his ov protection to trip. A diode across the relay coil fixed the problem. Bob . . . ________________________________________________________________________________
Date: May 20, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Any legacy regulator gurus out there?
> >Sir, I dont quite want to claim guru status, working on my previous C150A >from '61 it was similar and I did reset the V reg to around 14.4 - it was >sitting about 13 - and reset the I reg with a wirewound resistor (one of >those old monster types with the sliding clamp) to get the output up to 12 >amps or so from the 'as found' 6 amps. It was actually a 20 amp generator >but 12 is enough when the professional fix would be 100s of miles and $ away > >I dont recall whether I altered the gaps or tension for this but I did it >after cleaning the contacts from 40 years of pitting with a burnishing tool. > >Some time later I had a low charge again and discovered the aircraft >master switch - which thoughtfully includes cutoff contacts for the >generator field line - was in need of similar refurbishing. love these old >systems because they are actually repairable - just go to where the smoke >last escaped from... > >Moral of the story for me was I had wrongly assumed I knew enough not to >check the aircraft schematics first. In all probability the regulator may >have been OK but the worn switch in the field line had reduced the drive. >It did no harm checking the regulator and it would have been a shame to >have it binned as it looked like new inside just as the ones pictured. So >I concur with your notion to have him only mess with the V reg - perhaps >after cleaning the contacts and checking the other wiring for hidden >resistance. > >Ralph Thank you for sharing this. I'll include it in my compilation of hands-on experiences to forward to the gentleman who also has an old C-150! Bob . . . ________________________________________________________________________________
Date: May 20, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: battery tenders
> > >Hi db, >The older 42292 [or whatever (the previous generation)]did have a variable >resister on the circuit board. Nearly every one needed some adjustment as >I have a dozen or so. > >I purchased a minimum order of 100 ohm pots to install in the newer >units. I adjust them for 13.8 open circuit. > >I've repaired six or so [mine and others] as the common failure is the >transformer wire disconnects where it attaches to the plug that plugs into >the 110VAC. A sharp knife will separate the plastic housing around the >transformer providing access. I thought originally that trying to start >an engine with the unit connected would melt the solder at that joint but >I'm not sure. > >For the money they are hard to beat but as some say, you get what you pay >for.. >Earl Yup. The first "Battery Charger" I purchased from H.F. was this guy. http://aeroelectric.com/Pictures/Battery_Chargers/HF_Chargers/Junk_1.jpg It was simply a loosely regulated, low-level charger that might be classed as a "trickle-charger". No smarts at all meaning that its design did not attempt to produce a top-off charge followed by a non-charging support of terminal voltage for the purpose of offsetting internal leakage that would eventually discharge the battery. That device was evaluated years ago and it's a certainty that newer devices intended to compete in an increasingly sophisticated market will have improved features. The problem is a simple experiment to benchmark their performance for behavior and calibration which I will do as time permits. Bob . . . ________________________________________________________________________________
Date: May 20, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: battery tenders
> > >Hi db, >The older 42292 [or whatever (the previous generation)]did have a variable >resister on the circuit board. Nearly every one needed some adjustment as >I have a dozen or so. > >I purchased a minimum order of 100 ohm pots to install in the newer >units. I adjust them for 13.8 open circuit. > >I've repaired six or so [mine and others] as the common failure is the >transformer wire disconnects where it attaches to the plug that plugs into >the 110VAC. A sharp knife will separate the plastic housing around the >transformer providing access. I thought originally that trying to start >an engine with the unit connected would melt the solder at that joint but >I'm not sure. > >For the money they are hard to beat but as some say, you get what you pay >for.. >Earl > > >-- skyking135 wrote: >< > >I have one of the 42292 units and measured the output voltage on my >particular unit to be around 12.7 volts, noload. It was only getting the >battery up to about 12.3 volts; not enough to keep a good charge on a >battery. So, being the curious one that I am, I popped open the cover to >see if I could figure out how to adjust the output voltage. I found a >spot on the circuit board for a varistor (VR1) that had a 55ohm resistor >soldered in that postion. I figured that must adjust the output voltage. >I simply replaced the 55ohm resistor with a 22ohm one I had on hand. >That boosted the ouptut to a more respectable 13.2 volts. It still will >only charge up to about 12.9 volts which is better than the 12.3 is was >reaching before. I think I will adjust the resistor again to see if I >can squeeze out a little more performance. > >Quality control is not high on the list of priorities with Harbor >Freight. You get what you pay for. The question that is more difficult to answer is how does this product behave when LOADED with a discharged battery. How much current does it put out, for how long and to what terminal voltage? Does it produce a recharge voltage curve that looks anything like this? http://www.aeroelectric.com/Pictures/Curves/schumacher_2.jpg The voltage you're measuring at very low output current (open circuit) may be spoofing the charger into believing that it's connected to a fully charged battery and causes it to drop into the MAINTENANCE mode where the 12.9 volt level you cited is quite acceptable. A smart-charger is a crafty little bugger that takes a bit more than a one-time voltmeter check to deduce its capabilities. Adjusting them for a MAINTENANCE level of 13.8 volts would be contrary to the design goals for a true battery maintainer. Bob . . . ________________________________________________________________________________
From: "Andrew Butler" <andrewbutler(at)ireland.com>
Date: May 20, 2008
Subject: Re: S704-1 Relay Question
All I ever wanted to know about that particular component on the Z-figures and then some. I very much appreciate this valuable resource (all things Aeroelectric) and your attention to detail Bob. I wired up my first harness last weekend and attached it to my TruTrak servo. I did so with a relative amount of confidence in what I was doing, how I was doing it, why I was doing it and how I would continue doing it for the rest of the electrical system. Fantastic! Without this resource, I can honestly say that I would have been groping in the dark ending up with a low quality piecemeal whole rather than a high quality coherent one. Very many thanks for this and for the answers to my future questions. Andrew. ----- Original Message ----- From: "Robert L. Nuckolls, III" To: aeroelectric-list(at)matronics.com Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Date: Tue, 20 May 2008 09:06:38 -0500 > Okay, I've read the Wikipedia and aeroelectric articles. So far so good. > > So, in the absence of the diode, where is the "arc" likely to occur? If I have understood > correctly I'm saying at the E-BUS feed switch rather than at the switch in the relay. Am I > correct? > > If not, why does the arc occur at the relay switch and not the feed switch. It has to do with > the current flow path......... > > Thanks for your help. > > Andrew. Not sure what you're calling the "feed switch". With respect to contactors and relays, there is potential for effects of field collapse in an inductor to erode the contacts of the device that controls that contactor or relay. Hence, the long standing practice of adding spike suppression across the coils of such devices as illustrated in the Z-figures. Now, ANY time you break a circuit with the opening of hard contacts as in a switch, relay or contactor (that is carrying any amount of current at any voltage) there WILL be an arc formed in spreading gap between opening contacts. There was a school of thought circulated in the OBAM aircraft community a few years ago that for voltages and/or currents below some low level (I don't recall the numbers now) that no arcing would occur. So as an experiment, I took a miniature switch and sanded out the side of it like this: http://aeroelectric.com/Pictures/Switches/sm_switch_cutaway.jpg I fixtured it under the microscope and caused the NO contacts to carry 1 or 1/2 amp of current at 1.5 volts (alkaline d-cell). In a dark room I could clearly observe a tiny but bright blue arc in the spreading gap between the contacts when the circuit was broken. THIS ARCING IS NOT the phenomenon of concern with respect to noise or debilitating effects on controlling or controlled devices. Hence we rarely see arc suppression techniques applied to these effects. One exception is the quest for achieving the Beech Aircraft ov relay trip-life using relays some 30+ years ago as described in the chapter on OV Protection in the 'Connection. There is also a school of thought that suggests plain vanilla diodes across relay and contactor coils will cause a slowing of contact spreading velocity and is therefore an inducement to prolonged arcing at the opening contacts. Experiments on my bench showed that while adding a diode did indeed cause a DELAY IN OPENING of the contacts . . . http://www.aeroelectric.com/Pictures/Curves/704-1DelayNoDiode.gif http://www.aeroelectric.com/Pictures/Curves/704-1DelayWithDiode.gif . . . use of the plain vanilla diode produced no significant slowing of contact spreading velocity once they started to move. http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeWithDiode.gif In any case, the arcing produced either at controlling switches -OR- contacts of the controlled devices IS NOT a widespread threat for damage to other components in the system. The strongest effect you'll experience from the behavior of an unsuppressed relay or contactor coil is a transient interference event. A few years ago I helped a builder track down why opening his avionics bus relay on an off-the-shelf integrated power distribution system caused his ov protection to trip. A diode across the relay coil fixed the problem. Bob . . . =========== =========== =========== =========== ________________________________________________________________________________
Subject: Re: S704-1 Relay Question
Date: May 20, 2008
From: <longg(at)pjm.com>
Great thread... In our world it seems like we take relays for granted. They are amazing gadgets and I wanted to find more information on them. Below is a great link with detail on the very popular Bosch relay. It should be very clear as to their great benefit. There is no reason to stress a switch with a few of these in-line. http://www.bcae1.com/relays.htm#demo -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Andrew Butler Sent: Tuesday, May 20, 2008 10:45 AM To: aeroelectric-list(at)matronics.com Subject: Re: AeroElectric-List: Re: S704-1 Relay Question All I ever wanted to know about that particular component on the Z-figures and then some. I very much appreciate this valuable resource (all things Aeroelectric) and your attention to detail Bob. I wired up my first harness last weekend and attached it to my TruTrak servo. I did so with a relative amount of confidence in what I was doing, how I was doing it, why I was doing it and how I would continue doing it for the rest of the electrical system. Fantastic! Without this resource, I can honestly say that I would have been groping in the dark ending up with a low quality piecemeal whole rather than a high quality coherent one. Very many thanks for this and for the answers to my future questions. Andrew. ----- Original Message ----- From: "Robert L. Nuckolls, III" To: aeroelectric-list(at)matronics.com Subject: Re: AeroElectric-List: Re: S704-1 Relay Question Date: Tue, 20 May 2008 09:06:38 -0500 Nuckolls, III" > Okay, I've read the Wikipedia and aeroelectric articles. So far so good. > > So, in the absence of the diode, where is the "arc" likely to occur? If I have understood > correctly I'm saying at the E-BUS feed switch rather than at the switch in the relay. Am I > correct? > > If not, why does the arc occur at the relay switch and not the feed switch. It has to do with > the current flow path......... > > Thanks for your help. > > Andrew. Not sure what you're calling the "feed switch". With respect to contactors and relays, there is potential for effects of field collapse in an inductor to erode the contacts of the device that controls that contactor or relay. Hence, the long standing practice of adding spike suppression across the coils of such devices as illustrated in the Z-figures. Now, ANY time you break a circuit with the opening of hard contacts as in a switch, relay or contactor (that is carrying any amount of current at any voltage) there WILL be an arc formed in spreading gap between opening contacts. There was a school of thought circulated in the OBAM aircraft community a few years ago that for voltages and/or currents below some low level (I don't recall the numbers now) that no arcing would occur. So as an experiment, I took a miniature switch and sanded out the side of it like this: http://aeroelectric.com/Pictures/Switches/sm_switch_cutaway.jpg I fixtured it under the microscope and caused the NO contacts to carry 1 or 1/2 amp of current at 1.5 volts (alkaline d-cell). In a dark room I could clearly observe a tiny but bright blue arc in the spreading gap between the contacts when the circuit was broken. THIS ARCING IS NOT the phenomenon of concern with respect to noise or debilitating effects on controlling or controlled devices. Hence we rarely see arc suppression techniques applied to these effects. One exception is the quest for achieving the Beech Aircraft ov relay trip-life using relays some 30+ years ago as described in the chapter on OV Protection in the 'Connection. There is also a school of thought that suggests plain vanilla diodes across relay and contactor coils will cause a slowing of contact spreading velocity and is therefore an inducement to prolonged arcing at the opening contacts. Experiments on my bench showed that while adding a diode did indeed cause a DELAY IN OPENING of the contacts . . . http://www.aeroelectric.com/Pictures/Curves/704-1DelayNoDiode.gif http://www.aeroelectric.com/Pictures/Curves/704-1DelayWithDiode.gif . . . use of the plain vanilla diode produced no significant slowing of contact spreading velocity once they started to move. http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeWithDiode.gi f In any case, the arcing produced either at controlling switches -OR- contacts of the controlled devices IS NOT a widespread threat for damage to other components in the system. The strongest effect you'll experience from the behavior of an unsuppressed relay or contactor coil is a transient interference event. A few years ago I helped a builder track down why opening his avionics bus relay on an off-the-shelf integrated power distribution system caused his ov protection to trip. A diode across the relay coil fixed the problem. Bob . . . ========== ========== ========== ========== ________________________________________________________________________________
Date: May 20, 2008
From: Les Kearney <kearney(at)shaw.ca>
Subject: Contactor Locations
Bob Thanks for the help. I read in the Aeroelectric Guide that the contactor locations was not a big issue but wasn't sure how much flexibility I really had. A quick follow-up question: Will the electromagnets in the contactors be a problem for any avionics. My Magnometers will be in the tail so that is not a concern. Cheers Les -----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: May-20-08 7:45 AM Subject: Re: AeroElectric-List: Contactor Locations >Hi > > >I am trying to plan my RV10 electrical system and have a question for the >electrical mavens. That is, how far from avionics should battery >contactors be? I am looking at mounting my batteries in the sub panel area >and would like to co locate the contactors in the same area. Access is not >an issue but I am concerned about possible interference with the avionics. >I may end up locating the starter contactor on the same area as well. >Would this be a problem? > > >Cheers > > >Les Kearney Contactors are not high level antagonists to other components of the system. You mount contactors where it makes the most sense for their function. Battery contactors close to batteries, starter contactors close to starters, ect. In some architectures, they can be clustered together. In any case, there are no characteristics of a contactor that makes them a threat to anything other than the switch that controls them. See: http://www.aeroelectric.com/articles/spikecatcher.pdf http://www.aeroelectric.com/articles/spike.pdf Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: May 20, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Contactor Locations
> >Bob > >Thanks for the help. I read in the Aeroelectric Guide that the contactor >locations was not a big issue but wasn't sure how much flexibility I really >had. > >A quick follow-up question: Will the electromagnets in the contactors be a >problem for any avionics. My Magnometers will be in the tail so that is not >a concern. > Magnetometers ARE a potential victim of stray magnetic leakage from contactors but as a rule, if your magnetometer is at least 3' away from a potential antagonist, you're on solid ground. Another potential worry is stray field from the SD-20 alternator. We had problems with interference for a whisky compass mounted on the glare shield of the A36 . . . but the problem went away when the compass was moved upward about 10" onto the windshield. The effects of a potential antagonist on a magnetic navigation instrument is greatly attenuated by distance . . . a few more inches separation can make a lot of difference. On heavy iron birds, we usually mount magnetometers out in a wing just ahead of ailerons and use non-magnetic stainless fasteners in the immediate vicinity. Bob . . . ________________________________________________________________________________
Date: May 20, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: S704-1 Relay Question
>All I ever wanted to know about that particular component on the Z-figures >and then some. > >I very much appreciate this valuable resource (all things Aeroelectric) >and your attention to detail Bob. I wired up my first harness last weekend >and attached it to my TruTrak servo. I did so with a relative amount of >confidence in what I was doing, how I was doing it, why I was doing it and >how I would continue doing it for the rest of the electrical system. Fantastic! > >Without this resource, I can honestly say that I would have been groping >in the dark ending up with a low quality piecemeal whole rather than a >high quality coherent one. > >Very many thanks for this and for the answers to my future questions. Andrew. You're most welcome my friend. I'm pleased that you've found the work so useful. Bob . . . ________________________________________________________________________________
From: "Chris" <toaster73(at)embarqmail.com>
Subject: Fuse and Breaker - one bus
Date: May 20, 2008
I have been lurking here for a few years trying to absorb the power of aeroelectric but I am having trouble jumping from the schematics to the physical configuration. I am having trouble with the physical configuration of my RV-10 electrical system design. I am trying to draw up a Z-13 style system but I think I want my E-Bus to have a breaker for trim, flaps etc but the rest I want to use a fuse block. What would be a good way to combine the fuse and breaker block into one bus? Just run same gage wire to the e-bus primary and alternate feed to the fuse block and split off from block with same gage wire to the bar for the breakers? thanks in advance Chris Lucas RV-10 #40072 ________________________________________________________________________________
From: "Gaye and Vaughn" <vaughnray(at)bvunet.net>
Subject: Re: Fuse and Breaker - one bus
Date: May 20, 2008
The fuse block is your endurance bus. I would run a wire to the fuse block post that would handle the combined loads on the fuse block and the load on your breaker bar. I would then run a wire from the post on the fuse block to the breaker bar that was large enough to handle the combined loads of all the breakers. I once had an MGTF with Lucas electrics. Are you should be wiring? ;-) Vaughn Teegarden Trying to figure it out myself...Don't listen to me. ----- Original Message ----- From: "Chris" <toaster73(at)embarqmail.com> Sent: Tuesday, May 20, 2008 9:16 AM Subject: AeroElectric-List: Fuse and Breaker - one bus > > > I have been lurking here for a few years trying to absorb the power of > aeroelectric but I am having trouble jumping from the schematics to the > physical configuration. > I am having trouble with the physical configuration of my RV-10 electrical > system design. I am trying to draw up a Z-13 style system but I think I > want my E-Bus to have a breaker for trim, flaps etc but the rest I want to > use a fuse block. What would be a good way to combine the fuse and > breaker block into one bus? Just run same gage wire to the e-bus primary > and alternate feed to the fuse block and split off from block with same > gage wire to the bar for the breakers? > thanks in advance > Chris Lucas > RV-10 #40072 > > > ________________________________________________________________________________
Date: May 20, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Fuse and Breaker - one bus
> >I have been lurking here for a few years trying to absorb the power of >aeroelectric but I am having trouble jumping from the schematics to the >physical configuration. >I am having trouble with the physical configuration of my RV-10 electrical >system design. I am trying to draw up a Z-13 style system but I think I >want my E-Bus to have a breaker for trim, flaps etc but the rest I want to >use a fuse block. What would be a good way to combine the fuse and >breaker block into one bus? Just run same gage wire to the e-bus primary >and alternate feed to the fuse block and split off from block with same >gage wire to the bar for the breakers? >thanks in advance The e-bus is for things that you need during the en-route mode of flight to maximize utilization of a limited resource. If you're planning Z-13/8, then the e-bus can be easily configured to handle an endurance load of 8 amps. The idea is that when the airport is in sight that you can bring the main bus back on for using the battery to run anything on the main bus using a battery that's held completely in reserve for approach to landing. What's your rationale for breakers on these two systems? Runaway disconnect? Breakers are exceedingly poor substitutes for master disconnect systems . . . if indeed runaway is a high order probability for creating a hazard. It's probably easier to design a system that can't run away. In other words, trim is an exceedingly low duty-cycle load that runs happily from the e-bus . . . Flaps too for that matter . . . but they aren't needed until approach to landing and could stay on the main bus. I guess we need to understand your concnerns. Bob . . . ________________________________________________________________________________
Subject: Coil Suppression Techniques.
From: "Eric M. Jones" <emjones(at)charter.net>
Date: May 21, 2008
I have this weird Deja Vu feeling that we have covered this subject before. And I will save you the trouble Bob....I know you'll never agree, and you'll retort with a long quasi-techno piece and then stumble TO EXACTLY THE WRONG CONCLUSION. Coil suppression and relay contact arcing have been well studied: See: http://relays.tycoelectronics.com/appnotes/ Basically (ESPECIALLY with contactors) Do not use diodes for coil suppression unless you're hoping for greatly reduced relay/contactor life, so you can get stuck in a remote area and have an adventure. I know people like this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit! Here's what sane people have figured out: Mechanical relays and contactors depend upon magnetism generated by an electric current running through a wire coil. When the current stops, the magnetic field collapses. But the relay does not know the difference between a wire coil moving in a magnetic field (as in a generator) or a magnetic field moving in a wire coil (as in a collapsing magnetic field). Thus a large voltage1000V to 1500V typicallyis induced in the coil. This current goes the same direction the original current didso it slows the contact openingallowing arcing, chatter, bouncing, contact welding and even re-closure! Yikes! The common palliative is a diode AND zener in series, or better yet, a bidirectional zener across the coil. They call these Transils, Surmetics, Transorbs, TranZorbs, TransGuards, Mosorbs; the list is endless. (Over-paid executives dream up these names.) They are generic P6KE18CA bidirectional zeners. Jeeeeeze........ -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184184#184184 Attachments: http://forums.matronics.com//files/snapjack_101.pdf http://forums.matronics.com//files/snapjack_182.pdf ________________________________________________________________________________
Date: May 21, 2008
From: "sam(at)fr8dog.net" <sam.marlow(at)adelphia.net>
Subject: Re: Coil Suppression Techniques.
So Eric, do I just order a P6KE18CA, from Radio Shack, or do I need a specific Voltage rating for my relays on my 12v homebuilt? Sam ---- "Eric M. Jones" wrote: ============ I have this weird Deja Vu feeling that we have covered this subject before. And I will save you the trouble Bob....I know you'll never agree, and you'll retort with a long quasi-techno piece and then stumble TO EXACTLY THE WRONG CONCLUSION. Coil suppression and relay contact arcing have been well studied: See: http://relays.tycoelectronics.com/appnotes/ Basically (ESPECIALLY with contactors) Do not use diodes for coil suppression unless you're hoping for greatly reduced relay/contactor life, so you can get stuck in a remote area and have an adventure. I know people like this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit! Here's what sane people have figured out: Mechanical relays and contactors depend upon magnetism generated by an electric current running through a wire coil. When the current stops, the magnetic field collapses. But the relay does not know the difference between a wire coil moving in a magnetic field (as in a generator) or a magnetic field moving in a wire coil (as in a collapsing magnetic field). Thus a large voltage1000V to 1500V typicallyis induced in the coil. This current goes the same direction the original current didso it slows the contact openingallowing arcing, chatter, bouncing, contact welding and even re-closure! Yikes! The common palliative is a diode AND zener in series, or better yet, a bidirectional zener across the coil. They call these Transils, Surmetics, Transorbs, TranZorbs, TransGuards, Mosorbs; the list is endless. (Over-paid executives dream up these names.) They are generic P6KE18CA bidirectional zeners. Jeeeeeze........ -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184184#184184 Attachments: http://forums.matronics.com//files/snapjack_101.pdf http://forums.matronics.com//files/snapjack_182.pdf ________________________________________________________________________________
From: "John Cleary" <john_rv10(at)yahoo.com>
Subject: Coil Suppression Techniques
Date: May 22, 2008
Eric, Thank you for this contribution. I am planning to use a relay to switch power to my avionics/endurance busses. Normal loads at switch on/turn off would be in the order of 10 amps at 12 volts. What relay would you recommend and would you draw a simple diagram for a non electrical person showing how and where to wire the P6KE18CA bidirectional zener? Thanks once again, John -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of sam(at)fr8dog.net Sent: Thursday, 22 May 2008 5:43 AM Subject: Re: AeroElectric-List: Coil Suppression Techniques - use generic P6KE18CA bidirectional zener So Eric, do I just order a P6KE18CA, from Radio Shack, or do I need a specific Voltage rating for my relays on my 12v homebuilt? Sam ---- "Eric M. Jones" wrote: ============ I have this weird Deja Vu feeling that we have covered this subject before. And I will save you the trouble Bob....I know you'll never agree, and you'll retort with a long quasi-techno piece and then stumble TO EXACTLY THE WRONG CONCLUSION. Coil suppression and relay contact arcing have been well studied: See: http://relays.tycoelectronics.com/appnotes/ Basically (ESPECIALLY with contactors) Do not use diodes for coil suppression unless you're hoping for greatly reduced relay/contactor life, so you can get stuck in a remote area and have an adventure. I know people like this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit! Here's what sane people have figured out: Mechanical relays and contactors depend upon magnetism generated by an electric current running through a wire coil. When the current stops, the magnetic field collapses. But the relay does not know the difference between a wire coil moving in a magnetic field (as in a generator) or a magnetic field moving in a wire coil (as in a collapsing magnetic field). Thus a large voltage1000V to 1500V typicallyis induced in the coil. This current goes the same direction the original current didso it slows the contact openingallowing arcing, chatter, bouncing, contact welding and even re-closure! Yikes! The common palliative is a diode AND zener in series, or better yet, a bidirectional zener across the coil. They call these Transils, Surmetics, Transorbs, TranZorbs, TransGuards, Mosorbs; the list is endless. (Over-paid executives dream up these names.) They are generic P6KE18CA bidirectional zeners. Jeeeeeze........ -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184184#184184 Attachments: http://forums.matronics.com//files/snapjack_101.pdf http://forums.matronics.com//files/snapjack_182.pdf Checked by AVG. Checked by AVG. ________________________________________________________________________________
Subject: Coil Suppression Techniques.
Date: May 21, 2008
From: <longg(at)pjm.com>
So are we saying that people who market and sell relays bragging about 240,000 life clicks are full of mumbo jumbo? I know Radio Shack is. Should we buy a 40A relay to run a 30 A load and prolong the life of the switch? Jeeze, they're only a $1 more. Are we worried about something that will only be used for the life of the airplane? Ok, in reality I only turn the headlight on say, 100 times / year. That's probably 30 times more than average. At that rate I'll be long dead before I achieve 240k clicks. Radio Shack sells a lot of diodes to people who assume they provide feedback suppression. My BMW has an awful lot of Bosch relays that have never worn out. What are they doing to ensure long life? I crank up the headlights, horn etc in my car 10 X more than anything I do in the airplane. At $6 a piece I can carry a few into the backwoods. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of sam(at)fr8dog.net Sent: Wednesday, May 21, 2008 3:43 PM Subject: Re: AeroElectric-List: Coil Suppression Techniques. --> So Eric, do I just order a P6KE18CA, from Radio Shack, or do I need a specific Voltage rating for my relays on my 12v homebuilt? Sam ---- "Eric M. Jones" wrote: ============ --> I have this weird Deja Vu feeling that we have covered this subject before. And I will save you the trouble Bob....I know you'll never agree, and you'll retort with a long quasi-techno piece and then stumble TO EXACTLY THE WRONG CONCLUSION. Coil suppression and relay contact arcing have been well studied: See: http://relays.tycoelectronics.com/appnotes/ Basically (ESPECIALLY with contactors) Do not use diodes for coil suppression unless you're hoping for greatly reduced relay/contactor life, so you can get stuck in a remote area and have an adventure. I know people like this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit! Here's what sane people have figured out: Mechanical relays and contactors depend upon magnetism generated by an electric current running through a wire coil. When the current stops, the magnetic field collapses. But the relay does not know the difference between a wire coil moving in a magnetic field (as in a generator) or a magnetic field moving in a wire coil (as in a collapsing magnetic field). Thus a large voltage1000V to 1500V typicallyis induced in the coil. This current goes the same direction the original current didso it slows the contact openingallowing arcing, chatter, bouncing, contact welding and even re-closure! Yikes! The common palliative is a diode AND zener in series, or better yet, a bidirectional zener across the coil. They call these Transils, Surmetics, Transorbs, TranZorbs, TransGuards, Mosorbs; the list is endless. (Over-paid executives dream up these names.) They are generic P6KE18CA bidirectional zeners. Jeeeeeze........ -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184184#184184 Attachments: http://forums.matronics.com//files/snapjack_101.pdf http://forums.matronics.com//files/snapjack_182.pdf ________________________________________________________________________________
Date: May 21, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Coil Suppression Techniques.
> >I have this weird Deja Vu feeling that we have covered this subject >before. And I will save you the trouble Bob....I know you'll never agree, >and you'll retort with a long quasi-techno piece and then stumble TO >EXACTLY THE WRONG CONCLUSION. > >Coil suppression and relay contact arcing have been well studied: See: >http://relays.tycoelectronics.com/appnotes/ > >Basically (ESPECIALLY with contactors) Do not use diodes for coil >suppression unless you're hoping for greatly reduced relay/contactor life, >so you can get stuck in a remote area and have an adventure. I know people >like this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit! You've cited that document before. And I've read it several times both before you cited it and after you cited it. Kindly point out to me where the authors offer DATA supporting an assertion that the plain vanilla diode coil suppression has a profound effect on relay life. They correctly asserted and I confirmed that diodes do indeed extend the time from switch opening until energized contacts begin to move. This is opening delay. They went on to extrapolate that opening delay translates directly into slower contact spreading velocity and extrapolated further that this translated to increased contact wear. I did the experiments and published the results that argue against their extrapolations. If you have some data to the contrary, please share it with us. Just because you've read some words under the letter head and over the signatures of persons in high places does not make their words golden unless they're supported by data from and understanding of repeatable experiments. >Here's what sane people have figured out: . . . are you suggesting I am less than sane?? >Mechanical relays and contactors depend upon magnetism generated by an >electric current running through a wire coil. When the current stops, the >magnetic field collapses. But the relay does not know the difference >between a wire coil moving in a magnetic field (as in a generator) or a >magnetic field moving in a wire coil (as in a collapsing magnetic field). >Thus a large voltage1000V to 1500V typicallyis induced in the coil. >This current goes the same direction the original current didso it >slows the contact openingallowing arcing, chatter, bouncing, contact >welding and even re-closure! Yikes! Go to your workbench, measure it, document it and share it with us. Show me where my data and interpretation of my data is wrong. The important feature of relay and contactor operation that you're overlooking is the extreme relationship between magnetic force and air-gap. Air is an exceedingly poor conductor of magnetic lines of force. So while a diode does indeed slow the rate of drop in coil current (hence increased delay) once the armature comes unstuck from its seated condition, the effect of increasing air-gap is many times more influential than rate of decay in coil current. Went back to the workbench to look at the S704-1 in more detail. Here's the test setup: http://aeroelectric.com/Pictures/Schematics/Relay_Test_Setup.pdf Relay response with no coil suppression looks like this: http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_without_Diode.jpg where we see the high voltage spike on the coil trace and a 2.5 mS dropout delay. WITH a coil suppression diode, we get relay response like this: http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_with_Diode.jpg Dropout Delay is increased to 12.5 mS or about 5x longer than with the diode. This was the feature pointed out in the article you cited . . . where the authors extrapolated this into a commensurate slowing in contact spreading velocity (longer fires). However, when we take the diode off and look at transition time . . . http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_NoSuppression.jpg From the time the contacts FIRST open until they first contact the opposite side is 0.6 mS. Let's put the diode back on and we get . . . http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_Diode_Suppression.jpg Hmmm . . . transition increases to 0.75 mS, about a 25% increase NOT A 500% INCREASE. Let's go back an look at the traces I took where we were observing the arc in a spreading set of contacts with no diode . . . http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif Here I could see about 0.21 mS of "fire" as compared with . . . http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif about 0.23 mS arcing when the diode was in place. Hmmm, there was an increase but not a very big one. In both cases, observed arcing times were about 1/3 the total transition time. Now let us consider another feature of relays and contactors that REALLY drives service life issues. Take a look at: http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_with_Diode.jpg Where we see that after the first time the contacts touch, really get with the high-tempo hat-dance for perhaps several dozen closure and re-opening events. This means that for every operation of the switch on the panel, the contacts are getting 5-25 times more activity than the single switching event might suggest. Now look at: http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_without_Diode.jpg Well fooey . . . even with the diode off the contacts do the cat-on-a-hot-tin-roof routine. Let us further consider that when folks like those Tyco engineers evaluate service life, they're working in the laboratory test environment and evaluating products where service life is measured in the tens of thousands of operations . . . 50,000 typical. 250,000 is not unusual. Let us suppose that their paper was based on real statistical studies of dozens of relays with various coil suppression techniques and yes, there was an observable increase in mean operations between failures from 45,744 to 49,666 by "optimizing" the coil suppression. Hmmm . . . 10% . . . that IS significant to Tyco and probabably most of their customers. They didn't speak to this kind of study in the paper you cited and I'd like to believe they've done their homework. Let us assume their undocumented assertions WERE correct on the scale I suggested. How does this affect the OBAM aircraft builder who's switches, relays and contactors probably won't see 5,000 operations over the lifetime of the airplane? Further, environmental stresses will be root cause for most replacements of such devices in personally owned, non-revenue generating light aircraft, not electrical stresses. In any case, the 5x increase in drop-out delay DOES NOT extrapolate into a proportionate drop in contact life. >The common palliative is a diode AND zener in series, or better yet, a >bidirectional zener across the coil. They call these Transils, >Surmetics, Transorbs, TranZorbs, TransGuards, Mosorbs; the >list is endless. (Over-paid executives dream up these names.) They are >generic P6KE18CA bidirectional zeners. > >Jeeeeeze........ Eric, Of all the contributors to this list I expect more of you. We had some substantive discussions on the inner technical workings of various products and ideas in Plymouth a couple of years ago. You struck me as one who appreciates understanding and having a handle on the simple-ideas that go into your recipes for success. Please don't wave anyone's documents in the air as justification for an extrapolation of my infirmities. Let's not make this about you or me. May I suggest we explore, understand and then explain the physics. Make my day. Show me were I'm wrong. Bob . . . ________________________________________________________________________________
Date: May 21, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Coil Suppression Techniques (With Corrected Link)
I have this weird Deja Vu feeling that we have covered this subject before. And I will save you the trouble Bob....I know you'll never agree, and you'll retort with a long quasi-techno piece and then stumble TO EXACTLY THE WRONG CONCLUSION. Coil suppression and relay contact arcing have been well studied: See: http://relays.tycoelectronics.com/appnotes/ Basically (ESPECIALLY with contactors) Do not use diodes for coil suppression unless you're hoping for greatly reduced relay/contactor life, so you can get stuck in a remote area and have an adventure. I know people like this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit! You've cited that document before. And I've read it several times both before you cited it and after you cited it. Kindly point out to me where the authors offer DATA supporting an assertion that the plain vanilla diode coil suppression has a profound effect on relay life. They correctly asserted and I confirmed that diodes do indeed extend the time from switch opening until energized contacts begin to move. This is opening delay. They went on to extrapolate that opening delay translates directly into slower contact spreading velocity and extrapolated further that this translated to increased contact wear. I did the experiments and published the results that argue against their extrapolations. If you have some data to the contrary, please share it with us. Just because you've read some words under the letter head and over the signatures of persons in high places does not make their words golden unless they're supported by data from and understanding of repeatable experiments. Here's what sane people have figured out: . . . are you suggesting I am less than sane?? Mechanical relays and contactors depend upon magnetism generated by an electric current running through a wire coil. When the current stops, the magnetic field collapses. But the relay does not know the difference between a wire coil moving in a magnetic field (as in a generator) or a magnetic field moving in a wire coil (as in a collapsing magnetic field). Thus a large voltage1000V to 1500V typicallyis induced in the coil. This current goes the same direction the original current didso it slows the contact openingallowing arcing, chatter, bouncing, contact welding and even re-closure! Yikes! Go to your workbench, measure it, document it and share it with us. Show me where my data and interpretation of my data is wrong. The important feature of relay and contactor operation that you're overlooking is the extreme relationship between magnetic force and air-gap. Air is an exceedingly poor conductor of magnetic lines of force. So while a diode does indeed slow the rate of drop in coil current (hence increased delay) once the armature comes unstuck from its seated condition, the effect of increasing air-gap is many times more influential than rate of decay in coil current. Went back to the workbench to look at the S704-1 in more detail. Here's the test setup: http://aeroelectric.com/Pictures/Schematics/Relay_Test_Setup.pdf Relay response with no coil suppression looks like this: http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_without_Diode.jpg where we see the high voltage spike on the coil trace and a 2.5 mS dropout delay. WITH a coil suppression diode, we get relay response like this: http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_with_Diode.jpg Dropout Delay is increased to 12.5 mS or about 5x longer than with the diode. This was the feature pointed out in the article you cited . . . where the authors extrapolated this into a commensurate slowing in contact spreading velocity (longer fires). However, when we take the diode off and look at transition time . . . http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_NoSuppression.jpg From the time the contacts FIRST open until they first contact the opposite side is 0.6 mS. Let's put the diode back on and we get . . . http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_Diode_Suppression.jpg Hmmm . . . transition increases to 0.75 mS, about a 25% increase NOT A 500% INCREASE. Let's go back an look at the traces I took where we were observing the arc in a spreading set of contacts with no diode . . . http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif Here I could see about 0.21 mS of "fire" as compared with . . . (Here's the right trace) http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeWithDiode.gif about 0.23 mS arcing when the diode was in place. Hmmm, there was an increase but not a very big one. In both cases, observed arcing times were about 1/3 the total transition time. Now let us consider another feature of relays and contactors that REALLY drives service life issues. Take a look at: http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_with_Diode.jpg Where we see that after the first time the contacts touch, really get with the high-tempo hat-dance for perhaps several dozen closure and re-opening events. This means that for every operation of the switch on the panel, the contacts are getting 5-25 times more activity than the single switching event might suggest. Now look at: http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_without_Diode.jpg Well fooey . . . even with the diode off the contacts do the cat-on-a-hot-tin-roof routine. Let us further consider that when folks like those Tyco engineers evaluate service life, they're working in the laboratory test environment and evaluating products where service life is measured in the tens of thousands of operations . . . 50,000 typical. 250,000 is not unusual. Let us suppose that their paper was based on real statistical studies of dozens of relays with various coil suppression techniques and yes, there was an observable increase in mean operations between failures from 45,744 to 49,666 by "optimizing" the coil suppression. Hmmm . . . 10% . . . that IS significant to Tyco and probabably most of their customers. They didn't speak to this kind of study in the paper you cited and I'd like to believe they've done their homework. Let us assume their undocumented assertions WERE correct on the scale I suggested. How does this affect the OBAM aircraft builder who's switches, relays and contactors probably won't see 5,000 operations over the lifetime of the airplane? Further, environmental stresses will be root cause for most replacements of such devices in personally owned, non-revenue generating light aircraft, not electrical stresses. In any case, the 5x increase in drop-out delay DOES NOT extrapolate into a proportionate drop in contact life. The common palliative is a diode AND zener in series, or better yet, a bidirectional zener across the coil. They call these Transils, Surmetics, Transorbs, TranZorbs, TransGuards, Mosorbs; the list is endless. (Over-paid executives dream up these names.) They are generic P6KE18CA bidirectional zeners. Jeeeeeze........ Eric, Of all the contributors to this list I expect more of you. We had some substantive discussions on the inner technical workings of various products and ideas in Plymouth a couple of years ago. You struck me as one who appreciates understanding and having a handle on the simple-ideas that go into your recipes for success. Please don't wave anyone's documents in the air as justification for an extrapolation of my infirmities. Let's not make this about you or me. May I suggest we explore, understand and then explain the physics. Make my day. Show me were I'm wrong. Bob . . . -- Date: 5/20/2008 4:45 PM incoming mail is certified Virus Free. Checked by AVG. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Subject: Re: Coil Suppression Techniques.
From: "Eric M. Jones" <emjones(at)charter.net>
Date: May 21, 2008
Sam, P6KE18CA is 0.6kW 18V contained in the part number. Digikey has them. I wouldn't ever buy airplane parts from Radio Shack. They use fallouts, defects, out of tolerance, rejects, mismarked, etc. The last parts I got from them went right into the trash can. This is another issue Bob and I always disagree on. Or you can buy mine...."SnapJacks". I include free shipping, a handful of Fastons, insulating tubing, etc. But whatever you do, just don't use diodes (especially on CONTACTORS). If you REALLY don't want to use bidirectional zeners, then use the several other recommended methods better than the diode. Eric -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184277#184277 ________________________________________________________________________________
Date: May 22, 2008
From: "sam(at)fr8dog.net" <sam.marlow(at)adelphia.net>
Subject: Re: Coil Suppression Techniques.
Should I just use a diode in series with the snapjack, is it that simple? What about sizing the components? Thanks, Sam ---- "Eric M. Jones" wrote: ============ Sam, P6KE18CA is 0.6kW 18V contained in the part number. Digikey has them. I wouldn't ever buy airplane parts from Radio Shack. They use fallouts, defects, out of tolerance, rejects, mismarked, etc. The last parts I got from them went right into the trash can. This is another issue Bob and I always disagree on. Or you can buy mine...."SnapJacks". I include free shipping, a handful of Fastons, insulating tubing, etc. But whatever you do, just don't use diodes (especially on CONTACTORS). If you REALLY don't want to use bidirectional zeners, then use the several other recommended methods better than the diode. Eric -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184277#184277 ________________________________________________________________________________
Subject: Coil Suppression Techniques
Date: May 22, 2008
From: <max.johansson(at)nokia.com>
Eric This seems to be a well studied subject and after studying your results the method of parallelling a relay or contactor with an opposite direction diode seems to be the quick and dirty but still quite adequate method for the homebuilder. Now a very practical question: Is a 0.1 dollar 1N4001...4004 or similar diode strong enough to handle the collapsing energy of any relay or contactor used in a homebuilt ? best regards Max (just now wiring my 701 starter circuit) ________________________________________________________________________________
Subject: Re: Coil Suppression Techniques
From: "jetboy" <sanson.r(at)xtra.co.nz>
Date: May 22, 2008
Max, 1N5404 thru -8 series should do well with much more margin. I fitted one to the master solenoid on a Cessna150 once because the A&P in their collective wisdom neglected that small part as depicted it the Cessna parts book when replacing the old solenoid and damaged my master switch. My CH701 has a diode installed as required by the ACS ignition/start switch instructions and I think this one may have come with the switch. Ralph -------- Ralph - CH701 / 2200a Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184325#184325 ________________________________________________________________________________
Date: May 22, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Coil Suppression Techniques
>Eric > >This seems to be a well studied subject and after studying your results >the method of parallelling a relay or contactor with an opposite direction >diode seems to be the quick and dirty but still quite adequate method for >the homebuilder. > >Now a very practical question: > >Is a 0.1 dollar 1N4001...4004 or similar diode strong enough to handle the >collapsing energy of any relay or contactor used in a homebuilt Yes. Electrically the 1A diode is fine for about everything on the airplane. Recall that in the realm of reactive devices that store energy, the discharge begins at the same magnitude as the charging source. If you charge a capacitor to 100 volts, you get a reaction that starts at 100v and goes down from there when you discharge it. If you charge and inductor up to 1A, then when you release it from the charging source, the delivered reaction starts a 1A and goes down from there. Diodes have a steady state capability which is exemplified in their ratings . . . I.e, the 1N4001 is a 1A device. However, they also have transient ratings at much higher currents. For example, consulting the 1N400x data sheet at: http://aeroelectric.com/Mfgr_Data/Semiconductors/1N4001.pdf we read about an 8.3 mS non repetitive peak forward surge current rating of 30A. By "non-repeating", they don't mean "one time ever" but "just don't do this often." So as a transient current clamp on a manually operated contactor found in our airplanes the 1N400x series devices are electrically fine. However, I have often suggested that the larger siblings to the 1N400x (1N540x) devices have some mechanical advantages. They're still small but MUCH more robust than the little fellers. I selected these parts as power steering and coil suppressors of choice for the line of contactors I used to sell (which B&C still does). See: http://www.aeroelectric.com/Pictures/Contactors/s701-1l.jpg http://www.aeroelectric.com/Pictures/Contactors/s701-2.jpg The red PIDG terminal gets a good connection on the larger wires for these devices and the wires are robust enough to support the diode body under vibration levels typical of installations for these contactors. Radio Shack offers both sizes of diode: http://aeroelectric.com/Pictures/Misc/RS_Diodes.jpg Since a prohibition against Radio Shack parts has been suggested, I'll share an observation that there were times in the history of many suppliers of consumer/ experimenter parts where their offerings included industrial surplus parts of unknown but not necessarily evil pedigree. This includes a now premier supplier of goods (Digikey) who started out as a mail order supplier of industrial surplus that advertised in ham radio and experimenter electronics magazines. RS still handles experimenter's assortments of components that are reminiscent of "grab bags" offered in years gone by . . . http://tinyurl.com/5jhbu6 http://tinyurl.com/42jn9v . . . but these days, when you are responsible for managing inventory in thousands of stores, millions of catalogs, and a really big website, you don't spend time scrounging the back alleys of industrial trash cans looking for "floor sweepings". These components are so cheap that it simply doesn't pay to spend the time to salvage and then inventory less than factory-fresh components. The times they are a changing. As a final note, this thread is not intended to discourage anyone from using more sophisticated transient control techniques if that process rings their chimes. Information provided here is offered as a prophylactic against decision making based on poorly interpreted data, marketing hype, or sage advice from those who would disseminate but will not or cannot also teach. Bob . . . ________________________________________________________________________________
From: "bob noffs" <icubob(at)newnorth.net>
Subject: coil supression
Date: May 22, 2008
i believe b and c supplies a diode when you order a solenoid. bob noffs ________________________________________________________________________________
From: "John Cleary" <john_rv10(at)yahoo.com>
Subject: Re: Coil Suppression Techniques (With Corrected
Link)
Date: May 23, 2008
Great data Bob. Thanks, John -----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: Thursday, 22 May 2008 9:50 AM Subject: AeroElectric-List: Re: Coil Suppression Techniques (With Corrected Link) I have this weird Deja Vu feeling that we have covered this subject before. And I will save you the trouble Bob....I know you'll never agree, and you'll retort with a long quasi-techno piece and then stumble TO EXACTLY THE WRONG CONCLUSION. Coil suppression and relay contact arcing have been well studied: See: http://relays.tycoelectronics.com/appnotes/ Basically (ESPECIALLY with contactors) Do not use diodes for coil suppression unless you're hoping for greatly reduced relay/contactor life, so you can get stuck in a remote area and have an adventure. I know people like this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit! You've cited that document before. And I've read it several times both before you cited it and after you cited it. Kindly point out to me where the authors offer DATA supporting an assertion that the plain vanilla diode coil suppression has a profound effect on relay life. They correctly asserted and I confirmed that diodes do indeed extend the time from switch opening until energized contacts begin to move. This is opening delay. They went on to extrapolate that opening delay translates directly into slower contact spreading velocity and extrapolated further that this translated to increased contact wear. I did the experiments and published the results that argue against their extrapolations. If you have some data to the contrary, please share it with us. Just because you've read some words under the letter head and over the signatures of persons in high places does not make their words golden unless they're supported by data from and understanding of repeatable experiments. Here's what sane people have figured out: . . . are you suggesting I am less than sane?? Mechanical relays and contactors depend upon magnetism generated by an electric current running through a wire coil. When the current stops, the magnetic field collapses. But the relay does not know the difference between a wire coil moving in a magnetic field (as in a generator) or a magnetic field moving in a wire coil (as in a collapsing magnetic field). Thus a large voltage1000V to 1500V typicallyis induced in the coil. This current goes the same direction the original current didso it slows the contact openingallowing arcing, chatter, bouncing, contact welding and even re-closure! Yikes! Go to your workbench, measure it, document it and share it with us. Show me where my data and interpretation of my data is wrong. The important feature of relay and contactor operation that you're overlooking is the extreme relationship between magnetic force and air-gap. Air is an exceedingly poor conductor of magnetic lines of force. So while a diode does indeed slow the rate of drop in coil current (hence increased delay) once the armature comes unstuck from its seated condition, the effect of increasing air-gap is many times more influential than rate of decay in coil current. Went back to the workbench to look at the S704-1 in more detail. Here's the test setup: http://aeroelectric.com/Pictures/Schematics/Relay_Test_Setup.pdf Relay response with no coil suppression looks like this: http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_without_Diode.jpg where we see the high voltage spike on the coil trace and a 2.5 mS dropout delay. WITH a coil suppression diode, we get relay response like this: http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_with_Diode.jpg Dropout Delay is increased to 12.5 mS or about 5x longer than with the diode. This was the feature pointed out in the article you cited . . . where the authors extrapolated this into a commensurate slowing in contact spreading velocity (longer fires). However, when we take the diode off and look at transition time . . . http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_NoSuppression.jpg From the time the contacts FIRST open until they first contact the opposite side is 0.6 mS. Let's put the diode back on and we get . . . http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_Diode_Suppression.jpg Hmmm . . . transition increases to 0.75 mS, about a 25% increase NOT A 500% INCREASE. Let's go back an look at the traces I took where we were observing the arc in a spreading set of contacts with no diode . . . http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif Here I could see about 0.21 mS of "fire" as compared with . . . (Here's the right trace) http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeWithDiode.gif about 0.23 mS arcing when the diode was in place. Hmmm, there was an increase but not a very big one. In both cases, observed arcing times were about 1/3 the total transition time. Now let us consider another feature of relays and contactors that REALLY drives service life issues. Take a look at: http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_with_Diode.jpg Where we see that after the first time the contacts touch, really get with the high-tempo hat-dance for perhaps several dozen closure and re-opening events. This means that for every operation of the switch on the panel, the contacts are getting 5-25 times more activity than the single switching event might suggest. Now look at: http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_without_Diode.jpg Well fooey . . . even with the diode off the contacts do the cat-on-a-hot-tin-roof routine. Let us further consider that when folks like those Tyco engineers evaluate service life, they're working in the laboratory test environment and evaluating products where service life is measured in the tens of thousands of operations . . . 50,000 typical. 250,000 is not unusual. Let us suppose that their paper was based on real statistical studies of dozens of relays with various coil suppression techniques and yes, there was an observable increase in mean operations between failures from 45,744 to 49,666 by "optimizing" the coil suppression. Hmmm . . . 10% . . . that IS significant to Tyco and probabably most of their customers. They didn't speak to this kind of study in the paper you cited and I'd like to believe they've done their homework. Let us assume their undocumented assertions WERE correct on the scale I suggested. How does this affect the OBAM aircraft builder who's switches, relays and contactors probably won't see 5,000 operations over the lifetime of the airplane? Further, environmental stresses will be root cause for most replacements of such devices in personally owned, non-revenue generating light aircraft, not electrical stresses. In any case, the 5x increase in drop-out delay DOES NOT extrapolate into a proportionate drop in contact life. The common palliative is a diode AND zener in series, or better yet, a bidirectional zener across the coil. They call these Transils, Surmetics, Transorbs, TranZorbs, TransGuards, Mosorbs; the list is endless. (Over-paid executives dream up these names.) They are generic P6KE18CA bidirectional zeners. Jeeeeeze........ Eric, Of all the contributors to this list I expect more of you. We had some substantive discussions on the inner technical workings of various products and ideas in Plymouth a couple of years ago. You struck me as one who appreciates understanding and having a handle on the simple-ideas that go into your recipes for success. Please don't wave anyone's documents in the air as justification for an extrapolation of my infirmities. Let's not make this about you or me. May I suggest we explore, understand and then explain the physics. Make my day. Show me were I'm wrong. Bob . . . -- Date: 5/20/2008 4:45 PM incoming mail is certified Virus Free. Checked by AVG. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- Checked by AVG. Checked by AVG. ________________________________________________________________________________
Subject: Re: Coil Suppression Techniques
From: "Eric M. Jones" <emjones(at)charter.net>
Date: May 22, 2008
> Eric > This seems to be a well studied subject and after studying your results the method of parallelling a relay or contactor with an opposite direction diode seems to be the quick and dirty but still quite adequate method for the homebuilder. Now a very practical question: Is a 0.1 dollar 1N4001...4004 or similar diode strong enough to handle the collapsing energy of any relay or contactor used in a homebuilt ? > best regards > Max The coil's collapsing magnetic field when the contactor is de-energized induces a high current that travels in the same direction as the original holding current, but is of much greater magnitude. This is why the relay contacts chatter and arc on opening, can re-close (and even weld closed). This is bad for everything electrical, especially contacts. The bidirectional zeners are very cheap, and well worth it. The kit I sell will do your whole airplane, or go to Digikey if you want to save a few bucks and buy a dozen P6KE18CA. The question you imply, "Would it do for the homebuilder?"....My answer is NO, Bob's is YES. Take your pick. But Tyco, Potter and Brumfield, Kilovac, Gigavac, Zettler, Here's what Gigavac says: COIL SUPRESSION "....coil suppression techniques such as single diode, resistor capacitor combination, resistor, or varistor noticeably slow down the release time of the relay and can effect the life of the relay or the use of the relay in the application. In carry-only applications, the release time may not be important so these less expensive coil suppression techniques can be used. However, if the release/reset time is important, or if the contacts are to interrupt a load, do not use these techniques and use the recommended zener-zener or diode-zener combination." (underlining mine) Gigavac makes the GX-11 which is a great battery and starter contactor for your airplane, they also make really big high-current, high-voltage stuff. Diodes were 1960's technology. There's a better way now. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184398#184398 ________________________________________________________________________________
Date: May 22, 2008
From: Bob White <bob@bob-white.com>
Subject: Re: Coil Suppression Techniques
"Eric M. Jones" wrote: > > The coil's collapsing magnetic field when the contactor is de-energized induces a high current that travels in the same direction as the original holding current, but is of much greater magnitude. This is why the relay contacts chatter and arc on opening, can re-close (and even weld closed). This is bad for everything electrical, especially contacts. > > The bidirectional zeners are very cheap, and well worth it. The kit I sell will do your whole airplane, or go to Digikey if you want to save a few bucks and buy a dozen P6KE18CA. > > The question you imply, "Would it do for the homebuilder?"....My answer is NO, Bob's is YES. Take your pick. > > But Tyco, Potter and Brumfield, Kilovac, Gigavac, Zettler, > > Here's what Gigavac says: COIL SUPRESSION > > "....coil suppression techniques such as single diode, resistor capacitor combination, resistor, or varistor noticeably slow down the release time of the relay and can effect the life of the relay or the use of the relay in the application. In carry-only applications, the release time may not be important so these less expensive coil suppression techniques can be used. However, if the release/reset time is important, or if the contacts are to interrupt a load, do not use these techniques and use the recommended zener-zener or diode-zener combination." (underlining mine) Gigavac makes the GX-11 which is a great battery and starter contactor for your airplane, they also make really big high-current, high-voltage stuff. > > Diodes were 1960's technology. There's a better way now. > > -------- > Eric M. Jones > www.PerihelionDesign.com > 113 Brentwood Drive > Southbridge, MA 01550 > (508) 764-2072 > emjones(at)charter.net > > I think we need to revisit the physics here. The collapsing field induces a high VOLTAGE which is the opposite polarity of the applied voltage. The faster the current decreases, the higher the voltage spike. The suppression diode gives the current a place to go allowing it to decay more slowly, producing a lower voltage, reducing the arcing on the switch controlling the relay. The current will never exceed the original current flowing in the coil. Use of the suppression diode delays opening the relay because the current continues to flow for a longer time. The important point is that the suppression diode protects the switch controlling the relay. The effects on the relay contact arcing are secondary. Bob W. -- N93BD - Rotary Powered BD-4 - http://www.bob-white.com 3.8 Hours Total Time and holding Cables for your rotary installation - http://roblinstores.com/cables/ ________________________________________________________________________________
Subject: Coil Suppression Techniques
Date: May 22, 2008
From: <longg(at)pjm.com>
Thanks Bob et al, This is all very academic and provides excellent reading. Unfortunately I won't soon be a fellow in the IEEE and I have an airplane to build. Given the list of manufacturer's provided is there one who makes a quality relay with built in zener or combo protection for which I won't need to break out the heath kit? I want to use the relay to load my essential bus (alternate feed) as in Z-19. My expect load will be 25 amps. This is in keeping with the max load for the heat sink'd diode coming from the main bus. Glenn -----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: Thursday, May 22, 2008 9:13 AM Subject: Re: AeroElectric-List: Coil Suppression Techniques --> >Eric > >This seems to be a well studied subject and after studying your results >the method of parallelling a relay or contactor with an opposite >direction diode seems to be the quick and dirty but still quite >adequate method for the homebuilder. > >Now a very practical question: > >Is a 0.1 dollar 1N4001...4004 or similar diode strong enough to handle >the >collapsing energy of any relay or contactor used in a homebuilt Yes. Electrically the 1A diode is fine for about everything on the airplane. Recall that in the realm of reactive devices that store energy, the discharge begins at the same magnitude as the charging source. If you charge a capacitor to 100 volts, you get a reaction that starts at 100v and goes down from there when you discharge it. If you charge and inductor up to 1A, then when you release it from the charging source, the delivered reaction starts a 1A and goes down from there. Diodes have a steady state capability which is exemplified in their ratings . . . I.e, the 1N4001 is a 1A device. However, they also have transient ratings at much higher currents. For example, consulting the 1N400x data sheet at: http://aeroelectric.com/Mfgr_Data/Semiconductors/1N4001.pdf we read about an 8.3 mS non repetitive peak forward surge current rating of 30A. By "non-repeating", they don't mean "one time ever" but "just don't do this often." So as a transient current clamp on a manually operated contactor found in our airplanes the 1N400x series devices are electrically fine. However, I have often suggested that the larger siblings to the 1N400x (1N540x) devices have some mechanical advantages. They're still small but MUCH more robust than the little fellers. I selected these parts as power steering and coil suppressors of choice for the line of contactors I used to sell (which B&C still does). See: http://www.aeroelectric.com/Pictures/Contactors/s701-1l.jpg http://www.aeroelectric.com/Pictures/Contactors/s701-2.jpg The red PIDG terminal gets a good connection on the larger wires for these devices and the wires are robust enough to support the diode body under vibration levels typical of installations for these contactors. Radio Shack offers both sizes of diode: http://aeroelectric.com/Pictures/Misc/RS_Diodes.jpg Since a prohibition against Radio Shack parts has been suggested, I'll share an observation that there were times in the history of many suppliers of consumer/ experimenter parts where their offerings included industrial surplus parts of unknown but not necessarily evil pedigree. This includes a now premier supplier of goods (Digikey) who started out as a mail order supplier of industrial surplus that advertised in ham radio and experimenter electronics magazines. RS still handles experimenter's assortments of components that are reminiscent of "grab bags" offered in years gone by . . . http://tinyurl.com/5jhbu6 http://tinyurl.com/42jn9v . . . but these days, when you are responsible for managing inventory in thousands of stores, millions of catalogs, and a really big website, you don't spend time scrounging the back alleys of industrial trash cans looking for "floor sweepings". These components are so cheap that it simply doesn't pay to spend the time to salvage and then inventory less than factory-fresh components. The times they are a changing. As a final note, this thread is not intended to discourage anyone from using more sophisticated transient control techniques if that process rings their chimes. Information provided here is offered as a prophylactic against decision making based on poorly interpreted data, marketing hype, or sage advice from those who would disseminate but will not or cannot also teach. Bob . . . ________________________________________________________________________________
Subject: Re: Coil Suppression Techniques
From: "Eric M. Jones" <emjones(at)charter.net>
Date: May 22, 2008
> induces a high VOLTAGE which is the opposite polarity of the applied voltage. The faster the current decreases, the higher the voltage > spike. The suppression diode gives the current a place to go allowing > it to decay more slowly, producing a lower voltage, reducing the > arcing on the switch controlling the relay. The current will never > exceed the original current flowing in the coil. > > Use of the suppression diode delays opening the relay because the > current continues to flow for a longer time. The important point is > that the suppression diode protects the switch controlling the relay. > The effects on the relay contact arcing are secondary. Bob W. > -- > N93BD - Rotary Powered BD-4 - http://www.bob-white.com > 3.8 Hours Total Time and holding > Cables for your rotary installation - http://roblinstores.com/cables/ > If it were only so, what a nice world it would be! Please read: http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3311.pdf -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184415#184415 ________________________________________________________________________________
Date: May 22, 2008
From: Bob White <bob@bob-white.com>
Subject: Re: Coil Suppression Techniques
"Eric M. Jones" wrote: > > > > induces a high VOLTAGE which is the opposite polarity of the applied voltage. The faster the current decreases, the higher the voltage > > spike. The suppression diode gives the current a place to go allowing > > it to decay more slowly, producing a lower voltage, reducing the > > arcing on the switch controlling the relay. The current will never > > exceed the original current flowing in the coil. > > > > Use of the suppression diode delays opening the relay because the > > current continues to flow for a longer time. The important point is > > that the suppression diode protects the switch controlling the relay. > > The effects on the relay contact arcing are secondary. Bob W. > > -- > > N93BD - Rotary Powered BD-4 - http://www.bob-white.com > > 3.8 Hours Total Time and holding > > Cables for your rotary installation - http://roblinstores.com/cables/ > > > > > If it were only so, what a nice world it would be! Please read: > > http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3311.pdf > > -------- > Eric M. Jones > www.PerihelionDesign.com > 113 Brentwood Drive > Southbridge, MA 01550 > (508) 764-2072 > emjones(at)charter.net > OK, I've read it. What's your point? Quote: "When an electromechanical relay is de-energized rapidly by a mechanical switch or semiconductor, the collapsing magnetic field produces a substantial voltage transient in its effort to disperse the stored energy and oppose the sudden change of current flow." Note that this high voltage is not connected to the relay contacts and there is no mention of high currents being generated. It just doesn't happen. The high voltage is impressed across the switch controlling the relay. As Ralph (jetboy) recently posted, the A&P left off the diode resulting in the master switch being destroyed in his C150. All the problems with relay contact opening are associated with the slower opening time. Another quote: "The optimum switching life (for normally-open contacts) is therefore obtainew with a totally unsuppressed relay and statements of rated electrical life are usually based on this premise." In other words, for best contact life, don't use suppression. So why do we use it? To protect the controlling switch! Bob W. -- N93BD - Rotary Powered BD-4 - http://www.bob-white.com 3.8 Hours Total Time and holding Cables for your rotary installation - http://roblinstores.com/cables/ ________________________________________________________________________________
From: "Bill Bradburry" <bbradburry(at)bellsouth.net>
Subject: Previous Master solonoid clicking
Date: May 22, 2008
A while back, I discussed a clicking sound that I heard after I turned the alternator on when the engine was running. Today I discovered that my low voltage module was not working and when I removed it, the clicking went away. I tested the module by putting +9V on pin 4, grounded pin 5, and looked for the LED to come on and also for a ground to show up on pin 1. No light, no ground. Must have crapped out??!! I also noticed that when the module was disconnected, If I had the main battery set to "Alternator", and the engine battery set to "ON", I got about 13.4V. If I flipped the engine battery switch to "Auto", the voltage went up to about 14.6V. I was at a loss as to why this would be. I didn't try it with the engine battery set to "OFF", so I don't know what would have happened if I did. Does anyone have any ideas as to what was happening to cause the clicking if the module caused it, and why the voltage increase? I at first thought..I am turning one of the batteries off, so the voltage went up, but then I thought...why wouldn't the voltage regulator bring it back down in that case. Thanks for the help! Bill B ________________________________________________________________________________
From: "John Cleary" <john_rv10(at)yahoo.com>
Subject: Coil Suppression Techniques
Date: May 23, 2008
Bob, Reading all these comments, two questions come to mind. 1. Have you done the tests below with a zener-zener or a diode-zener combination to see how they compare with their IN 540x cousins? 2. Have you collected data on the effect on the switch controlling the relay to compare the four conditions:- No protection IN540x protection Zener-zerner protection Diode-zener protection? The data from question 1 will show us the effects on the relay under the various conditions being discussed. The data from Q2 will show us the effects on the switch controlling the relay under those same conditions. It seems both lots of data are required to determine the best way to protect the switch and at the same time protect the relay? - or am I missing something in this debate? Thanks once again, John -----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: Thursday, 22 May 2008 11:13 PM Subject: Re: AeroElectric-List: Coil Suppression Techniques >Eric > >This seems to be a well studied subject and after studying your results >the method of parallelling a relay or contactor with an opposite direction >diode seems to be the quick and dirty but still quite adequate method for >the homebuilder. > >Now a very practical question: > >Is a 0.1 dollar 1N4001...4004 or similar diode strong enough to handle the >collapsing energy of any relay or contactor used in a homebuilt Yes. Electrically the 1A diode is fine for about everything on the airplane. Recall that in the realm of reactive devices that store energy, the discharge begins at the same magnitude as the charging source. If you charge a capacitor to 100 volts, you get a reaction that starts at 100v and goes down from there when you discharge it. If you charge and inductor up to 1A, then when you release it from the charging source, the delivered reaction starts a 1A and goes down from there. Diodes have a steady state capability which is exemplified in their ratings . . . I.e, the 1N4001 is a 1A device. However, they also have transient ratings at much higher currents. For example, consulting the 1N400x data sheet at: http://aeroelectric.com/Mfgr_Data/Semiconductors/1N4001.pdf we read about an 8.3 mS non repetitive peak forward surge current rating of 30A. By "non-repeating", they don't mean "one time ever" but "just don't do this often." So as a transient current clamp on a manually operated contactor found in our airplanes the 1N400x series devices are electrically fine. However, I have often suggested that the larger siblings to the 1N400x (1N540x) devices have some mechanical advantages. They're still small but MUCH more robust than the little fellers. I selected these parts as power steering and coil suppressors of choice for the line of contactors I used to sell (which B&C still does). See: http://www.aeroelectric.com/Pictures/Contactors/s701-1l.jpg http://www.aeroelectric.com/Pictures/Contactors/s701-2.jpg The red PIDG terminal gets a good connection on the larger wires for these devices and the wires are robust enough to support the diode body under vibration levels typical of installations for these contactors. Radio Shack offers both sizes of diode: http://aeroelectric.com/Pictures/Misc/RS_Diodes.jpg Since a prohibition against Radio Shack parts has been suggested, I'll share an observation that there were times in the history of many suppliers of consumer/ experimenter parts where their offerings included industrial surplus parts of unknown but not necessarily evil pedigree. This includes a now premier supplier of goods (Digikey) who started out as a mail order supplier of industrial surplus that advertised in ham radio and experimenter electronics magazines. RS still handles experimenter's assortments of components that are reminiscent of "grab bags" offered in years gone by . . . http://tinyurl.com/5jhbu6 http://tinyurl.com/42jn9v . . . but these days, when you are responsible for managing inventory in thousands of stores, millions of catalogs, and a really big website, you don't spend time scrounging the back alleys of industrial trash cans looking for "floor sweepings". These components are so cheap that it simply doesn't pay to spend the time to salvage and then inventory less than factory-fresh components. The times they are a changing. As a final note, this thread is not intended to discourage anyone from using more sophisticated transient control techniques if that process rings their chimes. Information provided here is offered as a prophylactic against decision making based on poorly interpreted data, marketing hype, or sage advice from those who would disseminate but will not or cannot also teach. Bob . . . Checked by AVG. 7:21 AM Checked by AVG. 7:06 AM ________________________________________________________________________________
Date: May 22, 2008
From: Tony Gibson <umgibso1(at)yahoo.com>
Subject: Coil Suppression Techniques.
Hi Bob, on-behalf of myself and many others I'm sure I'd like to thank yo u for - first of all, your restraint, and of course-your informative post s that make it so easy for the rest of us to click-on the links of your -experiments.=0AI joined this list probably two years ago and a great dea l of what was discussed was over my head (and still is!) ... I received the daily emails and for the longest time would-check out the subject titles and more often than not delete the email.- Over time I've 'gotten up to speed', read your book, and spent the time to-learn-(whether the partic ular subject concerned my airplane or not).-=0AIt's all too easy to "gold plate the spec" to cover ALL conceivable conditions that a particular comp onent may see whether applicable or not.- It is of GREAT value to me that you repeatedly base your responses on OBAM-aircraft.- Meaning... if ag e/environmental factors, etc is going to kill my component before I or my d esigned system does then thats exactly what I need to know.--I have alw ays found your posts and advice to be practical in the real world (where mo st of us live with our little homebuilt airplanes)-and considerate of my time & money.=0AI continue to learn from all the contributors and contribut ions to the site.- Best Regards to all and my apologies for feeling the n eed to 'waste' bandwidth!- ;)=0ATony Gibson=0AWinnipeg, Manitoba-=0A=0A x.net>=0ASubject: Re: AeroElectric-List: Coil Suppression Techniques.=0A=0A Vu feeling that we have covered this subject =0A>before. And I will save y ou the trouble Bob....I know you'll never agree, =0A>and you'll retort with a long quasi-techno piece and then stumble TO =0A>EXACTLY THE WRONG CONCLU SION.=0A>=0A>Coil suppression- and relay contact arcing have been well st udied: See:=0A=0A>http://relays.tycoelectronics.com/appnotes/=0A>=0A>Basica lly (ESPECIALLY with contactors) Do not use diodes for coil =0A>suppression unless you're hoping for greatly reduced relay/contactor life, =0A>so you can get stuck in a remote area and have an adventure. I know people =0A>lik e this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit!=0A =0A- You've cited that document before. And I've=0A- read it several ti mes both before you cited it=0A- and after you cited it.=0A=0A- Kindly point out to me where the authors offer DATA=0A- supporting an assertion that the plain vanilla=0A- diode coil suppression has a profound effect o n relay life.=0A=0A- They correctly asserted and I confirmed that=0A- d iodes do indeed extend the time from switch=0A- opening until energized c ontacts begin to move.=0A- This is opening delay. They went on to extrapo late=0A- that opening delay translates directly into slower=0A- contact spreading velocity and extrapolated further=0A- that this translated to increased contact wear.=0A=0A- I did the experiments and published the re sults=0A- that argue against their extrapolations. If you=0A- have some data to the contrary, please share it=0A- with us.=0A=0A- Just because you've read some words under the=0A- letter head and over the signatures of persons=0A- in high places does not make their words golden=0A- unl ess they're supported by data from and=0A- understanding of repeatable ex periments.=0A=0A>Here's what sane people have figured out:=0A=0A- . . . - are you suggesting I am less than sane??=0A=0A>Mechanical relays and co ntactors depend upon magnetism generated by an =0A>electric current running through a wire coil. When the current stops, the =0A>magnetic field collap ses. But the relay does not know the difference =0A>between a wire coil mov ing in a magnetic field (as in a generator) or a =0A>magnetic field moving in a wire coil (as in a collapsing magnetic field). =0A>Thus a large voltag e1000V to 1500V typicallyis induced in the coil. =0A>This current goes the same direction the original current didso it =0A>slows the contact openinga llowing arcing, chatter, bouncing, contact =0A>welding and even re-closure! Yikes!=0A=0A- Go to your workbench, measure it, document=0A- it and sh are it with us. Show me where my=0A- data and interpretation of my data i s wrong.=0A=0A- The important feature of relay and contactor=0A- operat ion that you're overlooking is the extreme=0A- relationship between magne tic force and air-gap.=0A- Air is an exceedingly poor conductor of magnet ic=0A- lines of force. So while a diode does indeed slow=0A- the rate o f drop in coil current (hence increased=0A- delay) once the armature come s unstuck from its=0A- seated condition, the effect of increasing=0A- a ir-gap is many times more influential than rate=0A- of decay in coil curr ent.=0A=0A- Went back to the workbench to look at the S704-1 in=0A- mor e detail. Here's the test setup:=0A=0A=0Ahttp://aeroelectric.com/Pictures/S chematics/Relay_Test_Setup.pdf=0A=0A- Relay response with no coil suppres sion looks=0A- like this:=0A=0Ahttp://www.aeroelectric.com/Pictures/Curve s/S704-1_Drop-Out_Delay_without_Diode.jpg=0A=0A- where we see the high vo ltage spike on the coil=0A- trace and a 2.5 mS dropout delay.=0A=0A- WI TH a coil suppression diode, we get=0A- relay response like this:=0A=0Aht tp://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_with_Diode. jpg=0A=0A- Dropout Delay is increased to 12.5 mS or about 5x=0A- longer than with the diode. This was the feature=0A- pointed out in the article you cited . . . where=0A- the authors extrapolated this into a commensur ate=0A- slowing in contact spreading velocity (longer fires).=0A=0A- Ho wever, when we take the diode off and look at=0A- transition time . . . =0A=0Ahttp://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_NoS uppression.jpg=0A=0A- From the time the contacts FIRST open until they=0A - first contact the opposite side is 0.6 mS. Let's=0A- put the diode ba ck on and we get . . .=0A=0Ahttp://www.aeroelectric.com/Pictures/Curves/S70 4-1_D-E_Transition_Diode_Suppression.jpg=0A=0A- Hmmm . . . transition inc reases to 0.75 mS, about=0A- a 25% increase NOT A 500% INCREASE.=0A=0A- Let's go back an look at the traces I took where=0A- we were observing t he arc in a spreading set of=0A- contacts with no diode . . .=0A=0Ahttp:/ /www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif=0A=0A- Here I could see about 0.21 mS of "fire" as compared=0A- with . . .=0A=0A http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif=0A =0A- about 0.23 mS arcing when the diode was in place. Hmmm,=0A- there was an increase but not a very big one. In both=0A- cases, observed arcin g times were about 1/3 the total=0A- transition time.=0A=0A- Now let us consider another feature of relays and contactors=0A- that REALLY drives service life issues. Take a look at:=0A=0Ahttp://www.aeroelectric.com/Pict ures/Curves/S704-1_Contact_Bounce_with_Diode.jpg=0A=0A- Where we see that after the first time the contacts=0A- touch, really get with the high-te mpo hat-dance=0A- for perhaps several dozen closure and re-opening=0A- events. This means that for every operation of the=0A- switch on the pane l, the contacts are getting=0A- 5-25 times more activity than the single switching=0A- event might suggest. Now look at:=0A=0Ahttp://www.aeroelect ric.com/Pictures/Curves/S704-1_Contact_Bounce_without_Diode.jpg=0A=0A- We ll fooey . . . even with the diode off the contacts=0A- do the cat-on-a-h ot-tin-roof routine.=0A=0A- Let us further consider that when folks like those Tyco=0A- engineers evaluate service life, they're working in=0A- the laboratory test environment and evaluating products=0A- where service life is measured in the tens of thousands=0A- of operations . . . 50,000 typical. 250,000 is not=0A- unusual. Let us suppose that their paper was based on=0A- real statistical studies of dozens of relays with=0A- var ious coil suppression techniques and yes, there=0A- was an observable inc rease in mean operations between=0A- failures from 45,744 to 49,666 by "o ptimizing" the=0A- coil suppression. Hmmm . . . 10% . . . that IS signifi cant=0A- to Tyco and probabably most of their customers.=0A- They didn' t speak to this kind of study in the paper=0A- you cited and I'd like to believe they've done their=0A- homework.=0A=0A- Let us assume their und ocumented assertions=0A- WERE correct on the scale I suggested. How does this=0A- affect the OBAM aircraft builder who's switches,=0A- relays an d contactors probably won't see 5,000=0A- operations over the lifetime of the airplane?=0A=0A- Further, environmental stresses will be root cause =0A- for most replacements of such devices in personally owned,=0A- non -revenue generating light aircraft, not electrical=0A- stresses. In any c ase, the 5x increase in drop-out delay=0A- DOES NOT extrapolate into a pr oportionate drop in contact=0A- life.=0A=0A=0A>The common palliative is a diode AND zener in series, or better yet, a =0A>bidirectional zener across the coil. They call these Transils, =0A>Surmetics, Transorbs, TranZorbs, T ransGuards, Mosorbs; the =0A>list is endless. (Over-paid executives dream u p these names.)- They are =0A>generic P6KE18CA bidirectional zeners.=0A> =0A>Jeeeeeze........=0A=0A- Eric,=0A=0A- Of all the contributors to thi s list I expect=0A- more of you. We had some substantive discussions=0A - on the inner technical workings of various products=0A- and ideas in Plymouth a couple of years ago. You=0A- struck me as one who appreciates understanding=0A- and having a handle on the simple-ideas that go=0A- i nto your recipes for success.=0A=0A- Please don't wave anyone's documents in the air as=0A- justification for an extrapolation of my infirmities. =0A- Let's not make this about you or me. May I suggest=0A- we explore, understand and then explain the=0A- physics. Make my day. Show me were I 'm wrong.=0A=0A- Bob . . .=0A=0A=0A ________________________________________________________________________________
From: "Chris" <toaster73(at)embarqmail.com>
Subject: Re: Fuse and Breaker - one bus
Date: May 22, 2008
Thanks Bob. I see your point and will continue along those lines you describe. I have been thinking I may want to see an indication of a failure on certain items by seeing that breaker button pop out. Is that really something I need to see or know or do I use another indicator like a light? -Chris ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> Sent: Tuesday, May 20, 2008 11:33 PM Subject: Re: AeroElectric-List: Fuse and Breaker - one bus > > > >> >> >>I have been lurking here for a few years trying to absorb the power of >>aeroelectric but I am having trouble jumping from the schematics to the >>physical configuration. >>I am having trouble with the physical configuration of my RV-10 electrical >>system design. I am trying to draw up a Z-13 style system but I think I >>want my E-Bus to have a breaker for trim, flaps etc but the rest I want to >>use a fuse block. What would be a good way to combine the fuse and >>breaker block into one bus? Just run same gage wire to the e-bus primary >>and alternate feed to the fuse block and split off from block with same >>gage wire to the bar for the breakers? >>thanks in advance > > The e-bus is for things that you need during the en-route > mode of flight to maximize utilization of a limited resource. > If you're planning Z-13/8, then the e-bus can be easily > configured to handle an endurance load of 8 amps. > > The idea is that when the airport is in sight that you > can bring the main bus back on for using the battery to > run anything on the main bus using a battery that's held > completely in reserve for approach to landing. > > What's your rationale for breakers on these two systems? > Runaway disconnect? Breakers are exceedingly poor substitutes > for master disconnect systems . . . if indeed runaway is > a high order probability for creating a hazard. It's > probably easier to design a system that can't run away. > In other words, trim is an exceedingly low duty-cycle > load that runs happily from the e-bus . . . Flaps too > for that matter . . . but they aren't needed until approach > to landing and could stay on the main bus. I guess we > need to understand your concnerns. > > Bob . . . > > > ________________________________________________________________________________
From: "Chris" <toaster73(at)embarqmail.com>
Subject: Re: Fuse and Breaker - one bus
Date: May 22, 2008
Vaughn, I had an MGB and am familiar with the Prince of Darkness. Your right I probably should not be doing wiring - to me this is the coolest part of the project when its done, but the worst to figure out and build. I am a mechanical guy through and through. -Chris ----- Original Message ----- From: "Gaye and Vaughn" <vaughnray(at)bvunet.net> Sent: Tuesday, May 20, 2008 10:48 PM Subject: Re: AeroElectric-List: Fuse and Breaker - one bus > > > The fuse block is your endurance bus. I would run a wire to the fuse block > post that would handle the combined loads on the fuse block and the load > on your breaker bar. I would then run a wire from the post on the fuse > block to the breaker bar that was large enough to handle the combined > loads of all the breakers. > > I once had an MGTF with Lucas electrics. Are you should be wiring? ;-) > > Vaughn Teegarden > Trying to figure it out myself...Don't listen to me. > > ----- Original Message ----- > From: "Chris" <toaster73(at)embarqmail.com> > To: > Sent: Tuesday, May 20, 2008 9:16 AM > Subject: AeroElectric-List: Fuse and Breaker - one bus > > >> >> >> I have been lurking here for a few years trying to absorb the power of >> aeroelectric but I am having trouble jumping from the schematics to the >> physical configuration. >> I am having trouble with the physical configuration of my RV-10 >> electrical system design. I am trying to draw up a Z-13 style system but >> I think I want my E-Bus to have a breaker for trim, flaps etc but the >> rest I want to use a fuse block. What would be a good way to combine the >> fuse and breaker block into one bus? Just run same gage wire to the e-bus >> primary and alternate feed to the fuse block and split off from block >> with same gage wire to the bar for the breakers? >> thanks in advance >> Chris Lucas >> RV-10 #40072 >> >> >> >> > > > ________________________________________________________________________________
Date: May 22, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Coil Suppression Techniques
> >Bob, > >Reading all these comments, two questions come to mind. > >1. Have you done the tests below with a zener-zener or a diode-zener >combination to see how they compare with their IN 540x cousins? Absolutely. The the worse case voltage spike occurs with zero suppression (where all energies are dissipated in the arcing across spreading switch contacts). The best scenario for arcing control is the plain vanilla diode where arcing is minimal because the negative going spike that would normally go -300 volts plus is clamped off at ground thus limiting the voltage stress across the switch contacts to 14 volts. >2. Have you collected data on the effect on the switch controlling the relay >to compare the four conditions:- > No protection > IN540x protection > Zener-zerner protection > Diode-zener protection? Sure. They all work within the limits of their physics. Even a plain resistor adds significant value for arc reduction . . . even if the least efficient of the lot. A capacitor/resistor combination works too. Recall the "condenser" across the points on an Kettering ignition system distributor? There's a LOT of ways each offering trade offs. But to date, I've discovered no simpler, easier to implement technique than use of the plain-vanilla diode. >The data from question 1 will show us the effects on the relay under the >various conditions being discussed. The data from Q2 will show us the >effects on the switch controlling the relay under those same conditions. It >seems both lots of data are required to determine the best way to protect >the switch and at the same time protect the relay? - or am I missing >something in this debate? I looked at all these variations and quite frankly they performed well. I thought I had the traces on my hard drive but I don't find them. If I get time tomorrow, I'll go plot them again. I've not included them in my offerings of data because they are all middle-ground for performance between NO suppression and the ULTIMATE suppression of a plain-vanilla diode. With one exception. At one time I personally embraced low voltage MOV's as viable contact preservation devices but discarded them after I went to the bench to check performance when a reader told me of his own experiments where visible arcing was not attenuated by any observable amount with MOVs. I was properly embarrassed and dutiful in correcting the gaff. It's one of those things that happens when understanding based on data sheets does not mesh with real world experiences. The debate here is not whether the alternative systems do their job. The debate is whether there is return on investment for acquiring "specialized" components sold not upon hard data and repeatable experiment. The only support is a kind of "new and improved" marketing hype based on poorly extrapolated conclusions in a "celebrity" document. In this case, engineers that published under the Tyco trade name. It appears Eric is unwilling to be a teacher based on his personal understanding of the physics supported by a willingness to explain it. I am saddened by this. I'll go get the data on the alternative techniques tomorrow. Bob . . . ________________________________________________________________________________
From: "John Cleary" <john_rv10(at)yahoo.com>
Subject: Coil Suppression Techniques
Date: May 23, 2008
Bob, You are a LEGEND. Thanks again, John -----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: Friday, 23 May 2008 1:33 PM Subject: RE: AeroElectric-List: Coil Suppression Techniques > >Bob, > >Reading all these comments, two questions come to mind. > >1. Have you done the tests below with a zener-zener or a diode-zener >combination to see how they compare with their IN 540x cousins? Absolutely. The the worse case voltage spike occurs with zero suppression (where all energies are dissipated in the arcing across spreading switch contacts). The best scenario for arcing control is the plain vanilla diode where arcing is minimal because the negative going spike that would normally go -300 volts plus is clamped off at ground thus limiting the voltage stress across the switch contacts to 14 volts. >2. Have you collected data on the effect on the switch controlling the relay >to compare the four conditions:- > No protection > IN540x protection > Zener-zerner protection > Diode-zener protection? Sure. They all work within the limits of their physics. Even a plain resistor adds significant value for arc reduction . . . even if the least efficient of the lot. A capacitor/resistor combination works too. Recall the "condenser" across the points on an Kettering ignition system distributor? There's a LOT of ways each offering trade offs. But to date, I've discovered no simpler, easier to implement technique than use of the plain-vanilla diode. >The data from question 1 will show us the effects on the relay under the >various conditions being discussed. The data from Q2 will show us the >effects on the switch controlling the relay under those same conditions. It >seems both lots of data are required to determine the best way to protect >the switch and at the same time protect the relay? - or am I missing >something in this debate? I looked at all these variations and quite frankly they performed well. I thought I had the traces on my hard drive but I don't find them. If I get time tomorrow, I'll go plot them again. I've not included them in my offerings of data because they are all middle-ground for performance between NO suppression and the ULTIMATE suppression of a plain-vanilla diode. With one exception. At one time I personally embraced low voltage MOV's as viable contact preservation devices but discarded them after I went to the bench to check performance when a reader told me of his own experiments where visible arcing was not attenuated by any observable amount with MOVs. I was properly embarrassed and dutiful in correcting the gaff. It's one of those things that happens when understanding based on data sheets does not mesh with real world experiences. The debate here is not whether the alternative systems do their job. The debate is whether there is return on investment for acquiring "specialized" components sold not upon hard data and repeatable experiment. The only support is a kind of "new and improved" marketing hype based on poorly extrapolated conclusions in a "celebrity" document. In this case, engineers that published under the Tyco trade name. It appears Eric is unwilling to be a teacher based on his personal understanding of the physics supported by a willingness to explain it. I am saddened by this. I'll go get the data on the alternative techniques tomorrow. Bob . . . Checked by AVG. 7:06 AM Checked by AVG. 7:06 AM ________________________________________________________________________________
Date: May 23, 2008
From: "Sam Hoskins" <shoskins(at)mchsi.com>
Subject: Simplicate my all-electric Electronic Fuel Injection
I'm looking some feedback of my electrical system, based on Z-19RB. You can get the pdf here: http://www.mistakeproofing.net/transfer/N202SH-Z-19RB.pdf This is a retrofit in my 20 year old composite Quickie Q-200. I do a lot of day VFR cross country with this plane and do some cross country racing. Since I am converting to "all electric" I would be interested in your thoughts about my proposed system. Besides the Dynon FlightDEK 180 the biggest change is the conversion to electronic fuel injection. I am using the EC-3 controller from Real World Solutions (RWS). You can see more about the controller here: http://www.rotaryaviation.com/eficont.html The EC-3 controller is divided into two sides, A & B. The fuel injector control and ignition outputs exit the box from a single connector via a shared relay. The controller can receive either a primary or secondary 12V power source. A few bullet points: - I am using a primary fuel pump and a backup fuel pump. I also have two transfer pumps. - I have not yet sized the batteries. - I have an existing AEC9005-201 low voltage monitor, without the relay control. - Output of the ECU will be shown on another page, perhaps later in the week. - I have not yet properly sized the fuses or the wires in this drawing. My concerns: - By the time I add strobes and position lights, I will have around 14 or 15 switches, which seems like a lot for a 650 lb. (empty weight) airplane. Is there a way I could minimize the switch count? - I am thinking about combining the E-buss and the main power bus to reduce switch count and the number of fuse blocks. I could easily shed the loads myself. - There seem to be a lot of components connected to the unswitched battery busses. I wonder if I should use CBs instead of fuses so I would have a shutoff during servicing. Anything else? Your input is very welcome. Thanks! Sam Hoskins Murphysboro, IL http://samhoskins.blogspot.com/ ________________________________________________________________________________
Date: May 23, 2008
From: "Sam Hoskins" <sam.hoskins(at)gmail.com>
Subject: Z-19RB - review and simplify?
I'm looking some feedback on my electrical system, based on Z-19RB. You can get the pdf here: http://www.mistakeproofing.net/transfer/N202SH-Z-19RB.pdf This is a retrofit in my 20 year old composite Quickie Q-200. I do a lot of day VFR cross country with this plane and do some cross country racing. Since I am converting to "all electric" I would be interested in your thoughts about my proposed system. Besides the Dynon FlightDEK 180 the biggest change is the conversion to electronic fuel injection. I am using the EC-3 controller from Real World Solutions (RWS). You can see more about the controller here: http://www.rotaryaviation.com/eficont.html The EC-3 controller is divided into two sides, A & B. The fuel injector control and ignition outputs exit the box from a single connector via a shared relay. The controller can receive either a primary or secondary 12V power source. A few bullet points: - I am using a primary fuel pump and a backup fuel pump. I also have two transfer pumps. - I have not yet sized the batteries. - I have an existing AEC9005-201 low voltage monitor, without the relay control. - Output of the ECU will be shown on another page, perhaps later in the week. - I have not yet properly sized the fuses or the wires in this drawing. My concerns: - By the time I add strobes and position lights, I will have around 14 or 15 switches, which seems like a lot for a 650 lb. (empty weight) airplane. Is there a way I could minimize the switch count? - I am thinking about combining the E-buss and the main power bus to reduce switch count and the number of fuse blocks. I could easily shed the loads myself. - There seem to be a lot of components connected to the unswitched battery busses. I wonder if I should use CBs instead of fuses so I would have a shutoff during servicing. Anything else? Your input is very welcome. Thanks! Sam Hoskins Murphysboro, IL http://samhoskins.blogspot.com/ ________________________________________________________________________________
Subject: Re: Coil Suppression Techniques
From: "Eric M. Jones" <emjones(at)charter.net>
Date: May 23, 2008
> induces a high VOLTAGE which is the opposite polarity of the applied voltage. The faster the current decreases, the higher the voltage > spike. The suppression diode gives the current a place to go allowing > it to decay more slowly, producing a lower voltage, reducing the > arcing on the switch controlling the relay. The current will never > exceed the original current flowing in the coil. > > Use of the suppression diode delays opening the relay because the > current continues to flow for a longer time. The important point is > that the suppression diode protects the switch controlling the relay. > The effects on the relay contact arcing are secondary. > > Bob W. Actually, Eric is in bed with the cold/flu. And Paul M. keeps calling me up to rant about politics.....Jeeeze. Let's clear the air regarding coil suppression. When the relay is closed (and as I said this is targeted mainly at contactor relays), the relay coil has a large amount of energy stored in its inductor. When the relay coil switch is opened, the field collapses and a problematic high voltage is produced (the voltage depends on the several construction variables). I think we agree to this point. Now, it might seem that the current produced by the collapsing field is opposite its normal direction. This is not so. The coil current is in the same direction, but the relay coil has changed from being the Load to being the Generator. If you look at the diode direction, you will see that a current in the opposite direction could not flow at all, and the diode would serve no purpose. I agree with Bob W. that the coil suppressor protects the switch and anything else that provides power to the relay. It also provides other beneficial effect. However, not having a coil suppressor is not an option. Indeed, the best way to preserve the contactor's own power contacts is to have NO coil suppressor and just rip them apart as fast and as far as possible as possible. But everything else would suffer. The common (and historic) coil suppression technique that minimized damage to other components like the on/off switch was to shunt the coil with a reversed bias diode (a diode arranged so that it does not normally conduct current). Now when the coil's magnetic field collapses, it induces a current that is shorted by the diode. The current flows through the coil and stops in a very short time, lowering the voltage by lengthening the field collapse time. This longer field collapse time is deleterious to the power contacts, and (by Tyco P&B's information) can actually cause momentary re-closure which manifests as chatter, bouncing, etc. I assume this depends on the load, and the particulars of the contactor. But this approach raises some red flags: 1) The diode must not be driven over-current. 2) The delay to opening must be minimized. 3) The suppression device should last longer than the contactor. 4) The ground bounce oscillations should be handled. (for inductive loads) Now this is where Bob N. and I part company. Bob runs tests and depends on experience, I just read technical papers and study spec sheets. I claim one should dump the diode and use a newer approach. Bob N. claims the diode is good enough. I claim the major purveyors of contactors now use back-to-back zeners or bidirectionals. Bob N. can show lots of relays that use diodes. There you go. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184508#184508 ________________________________________________________________________________
Date: May 23, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Coil Suppression Techniques.
>Hi Bob, on behalf of myself and many others I'm sure I'd like to thank you >for - first of all, your restraint, and of course your informative posts >that make it so easy for the rest of us to click on the links of your >experiments. > >I joined this list probably two years ago and a great deal of what was >discussed was over my head (and still is!) ... I received the daily emails >and for the longest time would check out the subject titles and more often >than not delete the email. Over time I've 'gotten up to speed', read your >book, and spent the time to learn (whether the particular subject >concerned my airplane or not). That's what Richard Feynman describes as "The Pleasure of Finding Things Out". Virtually every classroom we all sat in for the first time offered tons of information sometimes accompanied with lucid explanation and even real-life connections. It is not uncommon when "getting a drink from the fire hose" that certain simple-ideas don't catch on or fit into the current library of life experiences. But as you've alluded, there is an osmosis effect . . . tiny bits of the big drink soak in. At some point in the future, a sort of epiphany may take place when one realizes that "Yeah, I KNOW how that works". It still happens to me regularly. > >It's all too easy to "gold plate the spec" to cover ALL conceivable >conditions that a particular component may see whether applicable or >not. It is of GREAT value to me that you repeatedly base your responses >on OBAM aircraft. Meaning... if age/environmental factors, etc is going >to kill my component before I or my designed system does then thats >exactly what I need to know. I have always found your posts and advice to >be practical in the real world (where most of us live with our little >homebuilt airplanes) and considerate of my time & money. To me, being an engineer was the ideal connection between pure physics and people. I was exceedingly fortunate in my career to have some good teachers AND a charter to make my ideas play in the marketplace. I.e, offer competitive value that was attractive for performance, price and after-the-sale service. VERY few of my contemporaries have enjoyed so broad an experience. > >I continue to learn from all the contributors and contributions to the >site. Best Regards to all and my apologies for feeling the need to >'waste' bandwidth! ;) Forgive me but that "wasted bandwidth" canard is really raises the ol' blood pressure. It seems most often used by individuals who complain to other individuals about the use of a communications tool that is nobody's property . . . a term almost never used in a exchange that quests for understanding of simple ideas. If one wants to bemoan "wasted bandwidth", just hit any cable channel for an hour and make notes on what one learns that adds any value to their lives. I.e., how did the $time$ spent today make one's life any more enjoyable or confident tomorrow? I view $time$ spent here as an opportunity to fine tune my own skills as well as encouragement to broaden my own understanding. Folks on the List are not always aware of the $time$ spent to firm up a foundation for an reply before I post it. You folks are as useful to me as I hope I am to all of you. $Time$ and 'bandwidth' used in that endeavor is never a waste. Everyone on the List has an opportunity to be both student and teacher. It has nothing to do with the total experience of either individual. Any instance where understanding supported by repeatable experiment is exchanged, there is opportunity for growth for everyone who chooses to participate. Bob . . . ________________________________________________________________________________
From: "Bill Bradburry" <bbradburry(at)bellsouth.net>
Subject: Previous Master solonoid clicking
Date: May 23, 2008
I left out that my plane is wired closely to the Z-19 architecture. Also the low voltage module is one that I built using one of Bob's boards from the old model. Bill B A while back, I discussed a clicking sound that I heard after I turned the alternator on when the engine was running. Today I discovered that my low voltage module was not working and when I removed it, the clicking went away. I tested the module by putting +9V on pin 4, grounded pin 5, and looked for the LED to come on and also for a ground to show up on pin 1. No light, no ground. Must have crapped out??!! I also noticed that when the module was disconnected, If I had the main battery set to "Alternator", and the engine battery set to "ON", I got about 13.4V. If I flipped the engine battery switch to "Auto", the voltage went up to about 14.6V. I was at a loss as to why this would be. I didn't try it with the engine battery set to "OFF", so I don't know what would have happened if I did. Does anyone have any ideas as to what was happening to cause the clicking if the module caused it, and why the voltage increase? I at first thought..I am turning one of the batteries off, so the voltage went up, but then I thought...why wouldn't the voltage regulator bring it back down in that case. Thanks for the help! Bill B ________________________________________________________________________________
Date: May 23, 2008
From: Bob White <bob@bob-white.com>
Subject: Re: Coil Suppression Techniques
"Eric M. Jones" wrote: > > > > induces a high VOLTAGE which is the opposite polarity of the applied voltage. The faster the current decreases, the higher the voltage > > spike. The suppression diode gives the current a place to go allowing > > it to decay more slowly, producing a lower voltage, reducing the > > arcing on the switch controlling the relay. The current will never > > exceed the original current flowing in the coil. > > > > Use of the suppression diode delays opening the relay because the > > current continues to flow for a longer time. The important point is > > that the suppression diode protects the switch controlling the relay. > > The effects on the relay contact arcing are secondary. > > > > Bob W. > > > Actually, Eric is in bed with the cold/flu. And Paul M. keeps calling me up to rant about politics.....Jeeeze. > > Let's clear the air regarding coil suppression. > > When the relay is closed (and as I said this is targeted mainly at contactor relays), the relay coil has a large amount of energy stored in its inductor. When the relay coil switch is opened, the field collapses and a problematic high voltage is produced (the voltage depends on the several construction variables). I think we agree to this point. > > **** Now, it might seem that the current produced by the collapsing field is opposite its normal direction. This is not so. The coil current is in the same direction, but the relay coil has changed from being the Load to being the Generator. If you look at the diode direction, you will see that a current in the opposite direction could not flow at all, and the diode would serve no purpose. > > I agree with Bob W. that the coil suppressor protects the switch and anything else that provides power to the relay. It also provides other beneficial effect. However, not having a coil suppressor is not an option. > > Indeed, the best way to preserve the contactor's own power contacts is to have NO coil suppressor and just rip them apart as fast and as far as possible as possible. But everything else would suffer. > > The common (and historic) coil suppression technique that minimized damage to other components like the on/off switch was to shunt the coil with a reversed bias diode (a diode arranged so that it does not normally conduct current). Now when the coil's magnetic field collapses, it induces a > current that is shorted by the diode. The current flows through the coil and stops in a very short time, lowering the voltage by lengthening the field collapse time. > > This longer field collapse time is deleterious to the power contacts, and (by Tyco P&B's information) can actually cause momentary re-closure which manifests as chatter, bouncing, etc. I assume this depends on the load, and the particulars of the contactor. > > But this approach raises some red flags: > 1) The diode must not be driven over-current. > 2) The delay to opening must be minimized. > 3) The suppression device should last longer than the contactor. > 4) The ground bounce oscillations should be handled. (for inductive loads) > > Now this is where Bob N. and I part company. Bob runs tests and depends on experience, I just read technical papers and study spec sheets. I claim one should dump the diode and use a newer approach. Bob N. claims the diode is good enough. I claim the major purveyors of contactors now use back-to-back zeners or bidirectionals. Bob N. can show lots of relays that use diodes. > > There you go. > > -------- > Eric M. Jones > www.PerihelionDesign.com > 113 Brentwood Drive > Southbridge, MA 01550 > (508) 764-2072 > emjones(at)charter.net > > > OK, that's better. You have stated the physics correctly. The only minor point I might make is that the fourth paragraph is not entirely accurate (marked **** above). I wouldn't expect the current produced by the collapsing field to be in the opposite direction. What I did say was that the voltage generated by the collapsing field was of the opposite polarity to the originally applied voltage. If that weren't true, the diode wouldn't provide any benefit. As to the usefulness of a suppression technique more complex than a diode, it seems to me that Bob N.'s test have shown that the effect on the contactors used in OBAM aircraft is fairly minor. It's interesting that the table shown in the PDF you referenced earlier shows the relationship between various suppression techniques and drop out time when the important factor is armature velocity. Did the engineers that wrote this paper take any data on armature velocity? They don't say. Did they test hundreds of relays to failure? The don't say. A tech paper needs to be based on experience or it's of little value. Bob's data shows a reduction in armature velocity. That is consistent with statements in the PDF. Bob has characterized the reduction and concluded that it's minor, based on his invaluable experience. Bob W. -- N93BD - Rotary Powered BD-4 - http://www.bob-white.com 3.8 Hours Total Time and holding Cables for your rotary installation - http://roblinstores.com/cables/ ________________________________________________________________________________
Date: May 23, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Coil Suppression Techniques
> > > > induces a high VOLTAGE which is the opposite polarity of the applied > voltage. The faster the current decreases, the higher the voltage > > spike. The suppression diode gives the current a place to go allowing > > it to decay more slowly, producing a lower voltage, reducing the > > arcing on the switch controlling the relay. The current will never > > exceed the original current flowing in the coil. > > > > Use of the suppression diode delays opening the relay because the > > current continues to flow for a longer time. The important point is > > that the suppression diode protects the switch controlling the relay. > > The effects on the relay contact arcing are secondary. > > > > Bob W. > > >Actually, Eric is in bed with the cold/flu. And Paul M. keeps calling me >up to rant about politics.....Jeeeze. > >Let's clear the air regarding coil suppression. > >When the relay is closed (and as I said this is targeted mainly at >contactor relays), the relay coil has a large amount of energy stored in >its inductor. When the relay coil switch is opened, the field collapses >and a problematic high voltage is produced (the voltage depends on the >several construction variables). I think we agree to this point. yes except that "large" is not quantified. We're talking a handful of millijoules. >Now, it might seem that the current produced by the collapsing field is >opposite its normal direction. This is not so. The coil current is in the >same direction, but the relay coil has changed from being the Load to >being the Generator. If you look at the diode direction, you will see that >a current in the opposite direction could not flow at all, and the diode >would serve no purpose. > >I agree with Bob W. that the coil suppressor protects the switch and >anything else that provides power to the relay. It also provides other >beneficial effect. However, not having a coil suppressor is not an option. ???? Tens of thousands of aircraft have flown out their lifetimes (and millions of cars ditto) with no coil collapse suppression on a variety of inductive loads. Service life of the controlling devices was perhaps less than what MIGHT be achieved but running without it was and still is AN OPTION in numerous antique vehicles including airplanes. >Indeed, the best way to preserve the contactor's own power contacts is to >have NO coil suppressor and just rip them apart as fast and as far as >possible as possible. But everything else would suffer. Agreed . . . but "everything else" and "suffering" are non-identified and non-quantified. >The common (and historic) coil suppression technique that minimized damage >to other components like the on/off switch was to shunt the coil with a >reversed bias diode (a diode arranged so that it does not normally conduct >current). Now when the coil's magnetic field collapses, it induces a >current that is shorted by the diode. The current flows through the coil >and stops in a very short time, lowering the voltage by lengthening the >field collapse time. agreed >This longer field collapse time is deleterious to the power contacts, and >(by Tyco P&B's information) can actually cause momentary re-closure which >manifests as chatter, bouncing, etc. I assume this depends on the load, >and the particulars of the contactor. I've never seen a spreading contact re-reclose. Have you some examples of where this has been observed? Chatter, bouncing . . . yes ALL contacts in switches, relays and contactors do not close and stay closed on first contact. I've seen as few as 2 or 3 closures- before-stable and as many as dozens. I counted over 25 bounces in one of traces I recently published Mercury wetted relays and solid-state switches are some exceptions. >But this approach raises some red flags: >1) The diode must not be driven over-current. Sure . . . but even the most delicate of silicon power rectifiers is not at risk for over-current in situations common to our aircraft. >2) The delay to opening must be minimized. Why? There ARE the occasional condition where TIMING is important. I've wrestled with "relay races" in circuits where relay-logic combinations were polluted because relay timing was not consistent or carefully accommodated. In every situation we're considering here, the relay or contactor is manually operated by crew . . . whether or not the contacts begin to move 1 mS or 50 mS after the pilot hits the switch is transparent to both the operator and to system performance. >3) The suppression device should last longer than the contactor. ??? Have you seen a contactor kill its own collapse suppressor? I just measured the inductance of an S701-1 contactor at 45 mH. LI^2/2 = (.045 x .9 x .9)/2 = 18 millijoules. The 1N4001 is rated to take 30A (1v drop) for 8.3 mS for 250 millijoles. My favorite diode 1N5400 is good for 200A for 8.3 mS for a spike catching capability of 1660 millijoules. I can't imagine where we'd encounter an energy- stress situation for coil suppression. >4) The ground bounce oscillations should be handled. (for inductive loads) Not sure how you're using "ground bounce". Inductance across a ground system is an issue within devices where very fast, tiny signals are handled. The ground system in a vehicle is exceedingly variable, difficult to control which is why we assume that products installed in an airplane should be able to withstand a variety of butt-ugly noises including "ground bounce". A diode across a relay coil has no significance to the generation or suppression of ground bounce as I perceive the phrase. If you have another perception, I'll need to understand it before I can intelligently discuss it. >Now this is where Bob N. and I part company. Bob runs tests and depends on >experience, . . . repeatable experiments are the ingredients that go into recipes for success. >I just read technical papers and study spec sheets. the printed word is an exceedingly important communications tool for teachers with simple-ideas to explain. At the same time, anyone can write down ideas that are easily mis-interpreted or are just plain wrong. One must always be wary of poorly explained ideas promoted only with convincing words. No teacher is insulted by honorable skepticism. > I claim one should dump the diode and use a newer approach. Bob N. > claims the diode is good enough. . . . for relays and contactors as WE use them in OUR airplanes. I will happily use any alternative technique that improves on performance, reliability or cost of ownership. Here's an example of arc suppression added across the contacts of my products control relay: http://aeroelectric.com/Pictures/Relays/Relay_with_Arc_Suppression_s.jpg Here the concern was for the effects of an inductive load on ME as the controlling device. I had no control over configuration of load so I had to cover the bases in the design of my product and put suppression on not on my coil but my contacts! > I claim the major purveyors of contactors now use back-to-back zeners or > bidirectionals. Bob N. can show lots of relays that use diodes. I don't thing we have "parted company" if you're agreeing that the diode is . . . (1) the ultimate transient suppressor from a energy management perspective, convenience and cost of ownership and . . . (2) causes an extended but insignificant drop-out delay for the ways we use relays and contactors and . . . (3) offers an insignificant influence upon service life for applications under discussion. I'll go plot the performance characteristics of 6-8 different ways to manage stored energy in a contactor coil. I'll also discuss the fact that selection of arc suppression techniques depend on the whole suite of design considerations that may go beyond starter/master switch and starter/ battery contactor service life. Bob . . . ________________________________________________________________________________
Subject: Z-19 hypothetical question
From: "user9253" <fran5sew(at)banyanol.com>
Date: May 23, 2008
Here is a hypothetical question for you electrical gurus. A pilot is flying on trip in a plane wired according to schematic Z-19. Shortly after takeoff the main battery contactor fails open. The pilot does not notice anything wrong because the engine battery contactor is closed and the alternator is still functioning. Eventually the main battery discharges due to loads on the main battery bus, and the pilot notices some things not working. He knows there is a problem but does not know the cause. Just to be safe, he closes the Endurance-Bus Alternate-Feed switch. The question is, does the charging current blow a fuse? (either one or both fuses) The current path is from the Main Power Distribution Bus, 7A fuse, diode, Endurance Bus, Alternate-Feed switch, fuse, Main Battery Bus, to the main battery. If the answer to the above question is yes, then everything on the Endurance Bus might not work for the remainder of the flight. I think the best solution is to increase the wire and fuse sizes in the above circuit. What size is required? Other possible solutions such as another diode or relay create additional problems. Joe Gores -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184591#184591 ________________________________________________________________________________
Subject: Re: Z-19RB - review and simplify?
From: "user9253" <fran5sew(at)banyanol.com>
Date: May 23, 2008
Do any of your electronic displays have voltage monitoring and alarm features? If so, you would not have to use that low voltage module. I would use fuses. They have several advantages. You will not be servicing equipment very often and you can pull a fuse. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184595#184595 ________________________________________________________________________________
Date: May 24, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Previous Master solonoid clicking
> > >I left out that my plane is wired closely to the Z-19 architecture. >Also the low voltage module is one that I built using one of Bob's boards >from the old model. > >Bill B > > >A while back, I discussed a clicking sound that I heard after I turned the >alternator on when the engine was running. >Today I discovered that my low voltage module was not working and when I >removed it, the clicking went away. How long has the system been in operation? Has it worked as expected for any period of time and is now behaving differntly? >I tested the module by putting +9V on pin 4, grounded pin 5, and looked for >the LED to come on and also for a ground to show up on pin 1. No light, no >ground. Must have crapped out??!! Send it back for evaluation/repair. You pay the postage to me, I'll pay it back to you. >I also noticed that when the module was disconnected, If I had the main >battery set to "Alternator", and the engine battery set to "ON", I got about >13.4V. If I flipped the engine battery switch to "Auto", the voltage went >up to about 14.6V. >I was at a loss as to why this would be. I didn't try it with the engine >battery set to "OFF", so I don't know what would have happened if I did. > >Does anyone have any ideas as to what was happening to cause the clicking if >the module caused it, and why the voltage increase? I at first thought..I >am turning one of the batteries off, so the voltage went up, but then I >thought...why wouldn't the voltage regulator bring it back down in that >case. A reasonable hypothesis suggests that the engine battery was discharged and was pulling the alternator down while it was huffing to push energy back into the battery. Putting the LVWarn/ABMM switch in the AUTO position with the module disconnected is the same as turning that battery OFF which would relieve the alternator of that re-charge load. You didn't mention what RPM the engine was running while these observations were made. It seems likely that the bus voltage would come raise while charging the battery if RPMs were high enough for alternator to develop full output. Suggest you put battery maintainers on both batteries. Let's evaluate/repair the LVWarn/ABMM module as needed before we carry the study further. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: May 24, 2008
From: "Robert Feldtman" <bobf(at)feldtman.com>
Subject: Re: Coil Suppression Techniques.
Cable TV is wasted bandwidth (except for cool channels like military channel, national geographic, NASCAR etc..) Otherwise I think cable TV kills Betz cells.. (that'll send folks heading for wikipedpia!) bobf On 5/23/08, Robert L. Nuckolls, III wrote: > > nuckolls.bob(at)cox.net> > > > Hi Bob, on behalf of myself and many others I'm sure I'd like to thank you >> for - first of all, your restraint, and of course your informative posts >> that make it so easy for the rest of us to click on the links of your >> experiments. >> >> I joined this list probably two years ago and a great deal of what was >> discussed was over my head (and still is!) ... I received the daily emails >> and for the longest time would check out the subject titles and more often >> than not delete the email. Over time I've 'gotten up to speed', read your >> book, and spent the time to learn (whether the particular subject concerned >> my airplane or not). >> > > That's what Richard Feynman describes as "The > Pleasure of Finding Things Out". Virtually every > classroom we all sat in for the first time offered > tons of information sometimes accompanied with > lucid explanation and even real-life connections. > It is not uncommon when "getting a drink from the > fire hose" that certain simple-ideas don't catch > on or fit into the current library of life experiences. > > But as you've alluded, there is an osmosis > effect . . . tiny bits of the big drink soak > in. At some point in the future, a sort of > epiphany may take place when one realizes that > "Yeah, I KNOW how that works". > > It still happens to me regularly. > >> >> It's all too easy to "gold plate the spec" to cover ALL conceivable >> conditions that a particular component may see whether applicable or not. >> It is of GREAT value to me that you repeatedly base your responses on OBAM >> aircraft. Meaning... if age/environmental factors, etc is going to kill my >> component before I or my designed system does then thats exactly what I need >> to know. I have always found your posts and advice to be practical in the >> real world (where most of us live with our little homebuilt airplanes) and >> considerate of my time & money. >> > > To me, being an engineer was the ideal connection > between pure physics and people. I was exceedingly > fortunate in my career to have some good teachers > AND a charter to make my ideas play in the marketplace. > I.e, offer competitive value that was attractive > for performance, price and after-the-sale service. > VERY few of my contemporaries have enjoyed so broad > an experience. > > >> I continue to learn from all the contributors and contributions to the >> site. Best Regards to all and my apologies for feeling the need to 'waste' >> bandwidth! ;) >> > > Forgive me but that "wasted bandwidth" canard is > really raises the ol' blood pressure. It seems most > often used by individuals who complain to other > individuals about the use of a communications tool > that is nobody's property . . . a term almost never > used in a exchange that quests for understanding of > simple ideas. > > If one wants to bemoan "wasted bandwidth", just > hit any cable channel for an hour and make notes on > what one learns that adds any value to their lives. > I.e., how did the $time$ spent today make one's life > any more enjoyable or confident tomorrow? > > I view $time$ spent here as an opportunity to > fine tune my own skills as well as encouragement > to broaden my own understanding. Folks on the List > are not always aware of the $time$ spent to firm > up a foundation for an reply before I post it. > You folks are as useful to me as I hope I am to > all of you. $Time$ and 'bandwidth' used in that > endeavor is never a waste. > > Everyone on the List has an opportunity to be both > student and teacher. It has nothing to do with > the total experience of either individual. Any > instance where understanding supported by repeatable > experiment is exchanged, there is opportunity > for growth for everyone who chooses to > participate. > > Bob . . . > > ________________________________________________________________________________
Date: May 24, 2008
From: Harley <harley(at)AgelessWings.com>
Subject: Re: Coil Suppression Techniques.
Right...thanks Bob...now I have to look up a web page full of more terms and words! Excerpt from Wikipedia: "Betz cells have one apical dendrite typical to pyramidal neurons, they have more primary dendritic shafts, and these do not leave the soma only at basal angles but rather branch out from almost any point asymmetrically." Harley ------------------------------------------------------------------------ Robert Feldtman wrote: > Cable TV is wasted bandwidth (except for cool channels like military > channel, national geographic, NASCAR etc..) Otherwise I think cable TV > kills Betz cells.. (that'll send folks heading for wikipedpia!) > > bobf > > ________________________________________________________________________________
From: "Bill Bradburry" <bbradburry(at)bellsouth.net>
Subject: Previous Master solonoid clicking
Date: May 24, 2008
Bob, Thanks for the evaluation/repair offer. I will send it in, but please remember that you only supplied the board. I supplied the components. You don't owe me any free repair! The engine, with this module working, has been running on the ground for probably 2 hours. I am not ready for flight yet. Bill -----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: Saturday, May 24, 2008 8:32 AM Subject: RE: AeroElectric-List: Previous Master solonoid clicking --> > > >I left out that my plane is wired closely to the Z-19 architecture. >Also the low voltage module is one that I built using one of Bob's >boards from the old model. > >Bill B > > >A while back, I discussed a clicking sound that I heard after I turned >the alternator on when the engine was running. >Today I discovered that my low voltage module was not working and when >I removed it, the clicking went away. How long has the system been in operation? Has it worked as expected for any period of time and is now behaving differntly? >I tested the module by putting +9V on pin 4, grounded pin 5, and looked >for the LED to come on and also for a ground to show up on pin 1. No >light, no ground. Must have crapped out??!! Send it back for evaluation/repair. You pay the postage to me, I'll pay it back to you. >I also noticed that when the module was disconnected, If I had the main >battery set to "Alternator", and the engine battery set to "ON", I got >about 13.4V. If I flipped the engine battery switch to "Auto", the >voltage went up to about 14.6V. >I was at a loss as to why this would be. I didn't try it with the >engine battery set to "OFF", so I don't know what would have happened if I did. > >Does anyone have any ideas as to what was happening to cause the >clicking if the module caused it, and why the voltage increase? I at >first thought..I am turning one of the batteries off, so the voltage >went up, but then I thought...why wouldn't the voltage regulator bring >it back down in that case. A reasonable hypothesis suggests that the engine battery was discharged and was pulling the alternator down while it was huffing to push energy back into the battery. Putting the LVWarn/ABMM switch in the AUTO position with the module disconnected is the same as turning that battery OFF which would relieve the alternator of that re-charge load. You didn't mention what RPM the engine was running while these observations were made. It seems likely that the bus voltage would come raise while charging the battery if RPMs were high enough for alternator to develop full output. Suggest you put battery maintainers on both batteries. Let's evaluate/repair the LVWarn/ABMM module as needed before we carry the study further. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________________________________________________________
Date: May 24, 2008
From: "Sam Hoskins" <shoskins(at)mchsi.com>
Subject: Re: Z-19RB - review and simplify?
I believe the D180 does have warnings, but since I already own Bob's LV warning gizmo, I thought I'd go ahead and use it anyway. Thanks for the input. Sam On Fri, May 23, 2008 at 8:03 PM, user9253 wrote: > > > > Do any of your electronic displays have voltage monitoring and alarm > features? If so, you would not have to use that low voltage module. > > I would use fuses. They have several advantages. You will not be > servicing equipment very often and you can pull a fuse. > > Joe > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=184595#184595 > > ________________________________________________________________________________
Date: May 24, 2008
From: "Sam Hoskins" <sam.hoskins(at)gmail.com>
Subject: Re: Z-19RB - review and simplify?
I believe the D180 does have warnings, but since I already own Bob's LV warning gizmo, I thought I'd go ahead and use it anyway. Thanks for the input. Sam On Fri, May 23, 2008 at 8:03 PM, user9253 wrote: > > > > Do any of your electronic displays have voltage monitoring and alarm > features? If so, you would not have to use that low voltage module. > > I would use fuses. They have several advantages. You will not be > servicing equipment very often and you can pull a fuse. > > Joe > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=184595#184595 > > ________________________________________________________________________________
Date: May 24, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Z-19 hypothetical question
> >Here is a hypothetical question for you electrical gurus. A pilot is >flying on trip in a plane wired according to schematic Z-19. Shortly >after takeoff the main battery contactor fails open. The pilot does not >notice anything wrong because the engine battery contactor is closed and >the alternator is still functioning. Eventually the main battery >discharges due to loads on the main battery bus, and the pilot notices >some things not working. He knows there is a problem but does not know >the cause. Just to be safe, he closes the Endurance-Bus Alternate-Feed >switch. The question is, does the charging current blow a fuse? (either >one or both fuses) The current path is from the Main Power Distribution >Bus, 7A fuse, diode, Endurance Bus, Alternate-Feed switch, fuse, Main >Battery Bus, to the main battery. EXCELLENT question! It's that "just to be safe" thinking that causes joe-pilot to stubs his toe. Every design feature of a system is (or at least should be) put in place for a specific purpose. In this case, the E-bus alternate feed switch is intended to provide an alternative power for e-bus powered electro-whizzies WHEN the main bus voltage falls too low to be a practical source of energy. 99.9+ percent of the time this is because the alternator is no longer supporting ship's loads for what ever reason. >If the answer to the above question is yes, then everything on the >Endurance Bus might not work for the remainder of the flight. I think the >best solution is to increase the wire and fuse sizes in the above >circuit. What size is required? Other possible solutions such as another >diode or relay create additional problems. Controls in our aircraft have beneficial effects that are addressed as part of a constellation of design goals. Some controls are not totally free of misadventure or even hazard for having been operated at an inappropriate time or inappropriate way. The only time I would close the e-bus alternate feed switch is after the low voltage warning light has informed me of a need for completing the flight battery(ies) only. Referring to . . . http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z19m_1.pdf http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z19m_2.pdf In the hypothetical you posed, electro-whizzies to first start spinning down would be the clock and the #2 fuel pump. Also, the engine would be complaining if the current configuration of switches had the engine running from the main battery instead of the engine battery. In this case, the first thing to do is bring the engine's alternative power switch ON to see if the engine gets happier. This is the hazard-free thing to do irrespective of how the engine was being powered before the "event". Once the engine is happy, use the voltmeter to explore the condition of the two batteries. One would quickly discover that for whatever reason, one of the batteries is low. Now is not the time to initiate trouble shooting procedures with switch-flipitis and non-piloting thought processes. Save all that fun stuff until parked on the ramp. Now, suppose a contactor fails during flight but the battery does not fall so low that electro-whizzies start complaining. It's conceivable that the airplane gets parked with an undiscovered latent failure. This is why the pre-flight check for dual battery airplanes is to turn battery switches on one at a time before starting the engine and comparing similarity of voltage readings for the two batteries under the same load. This will catch the latent failure before next flight. This brings up the rationale for separate normal and alternative engine power control switches as opposed to the multi-pole, two-position switches suggested by other designers. This hypothetical illustrates the feature of being able to ADD the alternative engine source to the current engine source . . . I.e. disturb as few controls in the present configuration as possible while resolving the appropriate plan-B for comfortable termination of flight. It also eliminates having mechanical failure of the single switch taking the engine power down. More than one dark-n-stormy night story has related situations where pilot fiddle-itis made things progressively worse. I had this conversation with a client just yesterday when the question was asked, "what happens if the warning light comes on, the pilot pulls the breaker and resets it, the warning light goes out and he tries to operate the system AGAIN and further aggravates the out-of-rig condition?" My answer was, "If the pilot survives to tell you about it, yank his job if not also his ticket". If the POH or the check-pilot that approved him for the aircraft doesn't cover the proper procedure for responding to that particular warning, then yank HIS job and/or ticket." The point is that carefully crafted systems need to be supported not just with good systems and human factors engineering. The teachers charged with insuring skill and understanding on the part of future users are just as critical as the designers. More folks die out of apathy/ignorance than of systems failure. Bob . . . ________________________________________________________________________________
Date: May 24, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Previous Master solonoid clicking
> > >Bob, >Thanks for the evaluation/repair offer. I will send it in, but please >remember that you only supplied the board. I supplied the components. You >don't owe me any free repair! But I do owe you a "grade" on your efforts with a goal of honing your skills. It also affords me a data point which may have future value. I've fielded a ton of incoming cabbages and tomatoes for allegedly faulty design and/or advice . . . all based on situations about which I was honorably skeptical but unable to defend for lack of hands-on experience. This was in spite of life-time, money-back guarantees so I suspect the allegations were bogus. But my warranty extends to both ideas and product so we're doing each other a favor here my friend. >The engine, with this module working, has been running on the ground for >probably 2 hours. I am not ready for flight yet. Understand. Let's see if we can figure out what's going on. Bob . . . ________________________________________________________________________________
Date: May 24, 2008
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Subject: Re: Z-19 hypothetical question
P.S. A product under development . . . http://www.aeroelectric.com/Catalog/AEC/9011/9011-700-1C.pdf has two channels of LOW Voltage warning. The second specifically intended to watch the aux battery for failure of contactor or failure of pilot to close said contactor. I don't think I'd put a low voltage warning in just for that purpose but in this case, it was about a 7% increase in parts count to add the feature to an existing design. Just some additional food for thought. Bob . . . ________________________________________________________________________________
Date: May 24, 2008
From: LarryMcFarland <larry(at)macsmachine.com>
Subject: memory versus tape
Hi Guys, Im wondering if anyone has plugged in a small voice recorder for ATC communications. The latest requirements have ATC providing total taxi instructions. That guidance has the tower rapidly describing a 7-point guidance that used to be 2 or 3-points. Its always been required to do a read-back to ATC in its entirety. Every ATC controller has his own creatively unique delivery that also complicates the pickup and read-back. Has anyone found a better way of dealing with this excessive mental-bandwidth aside from just more practice or a tape recorder? We need a better idea here,,,,,,,,,,,, Thanks, Larry McFarland 601HDS at www.macsmachine.com ________________________________________________________________________________
From: "earl_schroeder(at)juno.com" <earl_schroeder(at)juno.com>
Date: May 25, 2008
Subject: Re: memory versus tape
Hi Larry, I had a 'solid state' device sold by someone at Oshkosh years ago wired in but I could not figure how I was going to read back the recording short of just playing it to ATC. Somehow, I didn't think they would be happy with that solution.. As time passed, I figured out that they always deliver clearances in the exact order so I printed some address labels with blanks to insert the items that change.. worked for me. Now if ATC has no standard phraseology for taxi clearances, I would constantly ask for progressive instructions. I'll bet if a lot would, standardization would soon follow. :) Maybe this isn't a 'better idea' but my best shot. Earl -- LarryMcFarland wrote: Hi Guys, Im wondering if anyone has plugged in a small voice recorder for ATC communications. The latest requirements have ATC providing total taxi instructions. That guidance has the tower rapidly describing a 7-point guidance that used to be 2 or 3-points. Its always been required to do a read-back to ATC in its entirety. Every ATC controller has his own creatively unique delivery that also complicates the pickup and read-back. Has anyone found a better way of dealing with this excessive mental-bandwidth aside from just more practice or a tape recorder? We need a better idea here,,,,,,,,,,,, Thanks, Larry McFarland 601HDS at www.macsmachine.com ________________________________________________________________________________
From: "Scott Freeman" <sgfreeman(at)smyth.net>
Subject: Re: memory versus tape
Date: May 24, 2008
Look at the PS-Engineering PMA-4000 audio panel with voice record. It has a lot of functionality price and takes up little panel space. ----- Original Message ----- From: "LarryMcFarland" <larry(at)macsmachine.com> Sent: Saturday, May 24, 2008 7:44 PM Subject: AeroElectric-List: memory versus tape > > > Hi Guys, > > Im wondering if anyone has plugged in a small voice recorder for ATC > communications. The latest requirements have ATC providing total taxi > instructions. That guidance has the tower rapidly describing a 7-point > guidance that used to be 2 or 3-points. Its always been required to do a > read-back to ATC in its entirety. Every ATC controller has his own > creatively unique delivery that also complicates the pickup and read-back. > Has anyone found a better way of dealing with this excessive > mental-bandwidth aside from just more practice or a tape recorder? > > We need a better idea here,,,,,,,,,,,, > > Thanks, > > Larry McFarland 601HDS at www.macsmachine.com > > > ________________________________________________________________________________
Date: May 25, 2008
From: "Robert Feldtman" <bobf(at)feldtman.com>
Subject: Re: memory versus tape
short term memory, repitition and read back comes with practice, but at a towered airport with expected complex taxi instructions, have a pencil in your hand and paper on the knee before you call - and use some sort of "shorthand" to abbreviate as it comes across. More important than reading it back is following exactly what they tell you to do. I also almost always call the ground control before crossing any runway "Is 125GS cleared to cross 34?" Sometimes they get upset and say "your taxi clearance assumes that" but I don't care. I'd rather use 15 secs of radio than get twanged. Having the shorthand written instructions in front of you helps - you can also have on the other knee the airport diagram - No electronic gizmo is going to accomplish all that. But it is cool to show off to people. bobf On Sat, May 24, 2008 at 6:44 PM, LarryMcFarland wrote: > larry(at)macsmachine.com> > > Hi Guys, > > I'm wondering if anyone has plugged in a small voice recorder for ATC > communications. The latest requirements have ATC providing total taxi > instructions. That guidance has the tower rapidly describing a 7-point > guidance that used to be 2 or 3-points. It's always been required to do a > read-back to ATC in its entirety. Every ATC controller has his own > creatively unique delivery that also complicates the pickup and read-back. > Has anyone found a better way of dealing with this excessive > mental-bandwidth aside from just more practice or a tape recorder? > > We need a better idea here,,,,,,,,,,,, > > Thanks, > > Larry McFarland 601HDS at www.macsmachine.com > > ________________________________________________________________________________
Date: May 26, 2008
From: "ROGER & JEAN CURTIS" <mrspudandcompany(at)verizon.net>
Subject: Faraday Cage
I recently heard that all aircraft to be flown IFR must have a Faraday Cage in the structure. In other words it must be surrounded with a conductive material in the skin. This is to conduct static electricity. Does anyone know anything about this?? Or is it another myth? If there are any regulations, can you please point me to them. Thanks for your input. Roger ________________________________________________________________________________
Date: May 26, 2008
From: "Robert Feldtman" <bobf(at)feldtman.com>
Subject: Re: Faraday Cage
myth bobf W5RF On 5/26/08, ROGER & JEAN CURTIS wrote: > > > I recently heard that all aircraft to be flown IFR must have a Faraday Cage > in the structure. In other words it must be surrounded with a conductive > material in the skin. This is to conduct static electricity. > > > Does anyone know anything about this?? Or is it another myth? If there are > any regulations, can you please point me to them. > > > Thanks for your input. > > > Roger > > ________________________________________________________________________________
Subject: Re: memory versus tape
From: "Eric M. Jones" <emjones(at)charter.net>
Date: May 26, 2008
Don't try to look cool and pretend you know what you're doing if you are uncertain of the instructions, just say "Request Progressive Taxi Instructions." Progressive being the key word. Remember in all cases YOU are the customer who is to be served, not the ground controller. Remember "Confess, Communicate, Comply." always trumps, "Hold my beer...Watch this!" -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=184849#184849 ________________________________________________________________________________
From: BobsV35B(at)aol.com
Date: May 26, 2008
Subject: Re: memory versus tape
Good Morning Eric, The statement "Remember in all cases YOU are the customer who is to be served, not the ground controller" was the mantra used by the last two female leaders of the FAA. An order has recently been issued at the direction of Congressman Oberstar, that the FAA's business is not to be conducted in that manner. Instead, they are to consider that their mission is to issue violations. While the air traffic controllers are not, and most do not want to be, issuers of violations, they are in the same boat as we pilots when it comes to anything which jeopardize their employment. The new attitude stinks and it comes not only from congress, but from the current white house. Be careful out there. In addition to our needing to avoid physical danger, we need to be aware that the FAA is definitely not there to help. Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator 628 West 86th Street Downers Grove, IL 60516 630 985-8502 Stearman N3977A Brookeridge Air Park LL22 In a message dated 5/26/2008 8:29:16 A.M. Central Daylight Time, emjones(at)charter.net writes: Don't try to look cool and pretend you know what you're doing if you are uncertain of the instructions, just say "Request Progressive Taxi Instructions." Progressive being the key word. Remember in all cases YOU are the customer who is to be served, not the ground controller. Remember "Confess, Communicate, Comply." always trumps, "Hold my beer...Watch this!" **************Get trade secrets for amazing burgers. Watch "Cooking with Tyler Florence" on AOL Food. (http://food.aol.com/tyler-florence?video=4&?NCID=aolfod00030000000002) ________________________________________________________________________________
From: "Mark Means" <mtmeans(at)cox.net>
Subject: OV protection - internally regulated alternator
Date: May 26, 2008
I have been building an automotive conversion Velocity for many years now and have gone through the OV protection is good (I actually have an OV module I built and tested) to the "no longer recommended nor do we recommend internally regulated alternators". I am running my engine successfully, have Eaton contactors to isolate redundant batteries as well as the B lead which is controllable via CB. I also have the monster fuse in the B lead. I searched the archives for a couple hours and have seen much discussion on nuisance OV breaker trips and alternator problems. My questions are: - what are the odds of a runaway and is this usually a slow increase in voltage or rapid? - what is the problem with the OV protection with the internally regulated alternators if the module works as designed and pulls the alternator offline in a runaway situation? - if the alternative is electronic monitoring and pulling the alternator offline, is there a downside to this other than slow reflexes? - what are the foreseeable consequences of delays of pulling it offline? Thanks for any help sorting this out. Mark Means ________________________________________________________________________________
Date: May 26, 2008
From: Henador Titzoff <henador_titzoff(at)yahoo.com>
Subject: Re: Faraday Cage
Roger, I am willing to bet that you did NOT hear that from an FAA guy. I have never read that in the FARs. Just because I've never read it, though, doesn't mean it doesn't exist; however, I 've never heard it before, and there are many aircraft manufacturers out there like Cirrus, Diamond, etc. who have never it either. My experimental airplane is a composite fiberglass/foam airplane, and it's never heard of it. I will be very surprised if anyone on this email list will be able to quote a FAR that says so. Sounds like a good myth in the making to me. Henador Titzof ----- Original Message ---- From: ROGER & JEAN CURTIS <mrspudandcompany(at)verizon.net> Sent: Monday, May 26, 2008 8:33:19 AM Subject: AeroElectric-List: Faraday Cage I recently heard that all aircraft to be flown IFR must have a Faraday Cage in the structure. In other words it must be surrounded with a conductive material in the skin. This is to conduct static electricity. Does anyone know anything about this?? Or is it another myth? If there are any regulations, can you please point me to them. Thanks for your input. Roger ________________________________________________________________________________
Date: May 26, 2008
From: Henador Titzoff <henador_titzoff(at)yahoo.com>
Subject: Re: Faraday Cage
Roger, I am willing to bet that you did NOT hear that from an FAA guy. I have never read that in the FARs. Just because I've never read it, though, doesn't mean it doesn't exist; however, I 've never heard it before, and there are many aircraft manufacturers out there like Cirrus, Diamond, etc. who have never it either. My experimental airplane is a composite fiberglass/foam airplane, and it's never heard of it. I will be very surprised if anyone on this email list will be able to quote a FAR that says so. Sounds like a good myth in the making to me. Henador Titzof ----- Original Message ---- From: ROGER & JEAN CURTIS <mrspudandcompany(at)verizon.net> Sent: Monday, May 26, 2008 8:33:19 AM Subject: AeroElectric-List: Faraday Cage I recently heard that all aircraft to be flown IFR must have a Faraday Cage in the structure. In other words it must be surrounded with a conductive material in the skin. This is to conduct static electricity. Does anyone know anything about this?? Or is it another myth? If there are any regulations, can you please point me to them. Thanks for your input. Roger ________________________________________________________________________________
Subject: Re: Z-19 hypothetical question
From: "user9253" <fran5sew(at)banyanol.com>


May 12, 2008 - May 26, 2008

AeroElectric-Archive.digest.vol-hv