AeroElectric-Archive.digest.vol-cw

January 28, 2004 - February 10, 2004



From: "Dan Checkoway" <dan(at)rvproject.com>
Subject: Fw: RV-7 wing tip COM antenna installation
Date: Jan 28, 2004
FYI, here's Bob's response. )_( Dan ----- Original Message ----- From: "Bob Archer" <bobsantennas(at)earthlink.net> Subject: Re: RV-7 wing tip COM antenna installation > > ----- Original Message ----- > From: "Dan Checkoway" <dan(at)rvproject.com> > To: "Bob Archer" > Cc: > Sent: Tuesday, January 27, 2004 11:53 PM > Subject: RV-7 wing tip COM antenna installation > > Hi Dan; > > The Com antenna was developed when the Horner type tips were in vogue, where > the bottom surface sweeps up to the upper surface. I still like them better > from my point of view. But we now have to contend with the so called sheared > tips. > > The picture you showed with the antenna sweeping up to the upper surface is > fine. A local fellow put in a sheet of fiber glass angled from the bottom to > the top with the antenna installed on it. He bent the antenna up just next > to the grounding strip. > > The antenna needs to be grounded along the grounding strip, wires are not > good. If you installed a sheet of aluminum between the grounding strip and > the end of the wing for grounding that would suffice. Sandwiching the > antenna between the tip and the glass is the normal way to do it. > > About routing the wires to the lights, I don't know. I know it works well > the way it is shown on the drawing but other than that? I would guess that > it would be ok but I have been fooled before. There are so many different > ways things could be done I haven't been able to test for every possibility. > > Just let me know if you have any further questions. > > Regards > > Bob > > > > Bob, > > > > I purchased wing tip VOR & COM antennas from you last year, and I'm > finally > > getting around to installing them. The VOR antenna installation is a > > no-brainer thanks to your instructions. The COM antenna, however, is a > > little trickier due to the shape of the RV-7 wing tips (sheared, with > > built-in lighting provision). > > > > Here is a web page with photos to illustrate my issues: > > > > http://www.rvproject.com/archer.html > > > > 1) Can the antenna be somewhat tightly arched and still perform well? > > Bending it in an arch would improve its vertical profile, if that's > > acceptable. > > > > 2) Can the antenna be grounded with a wire instead of directly contacting > > the airframe? I'd like to mount it a few inches outboard from the wing > tip > > opening, and I assume I would need to use a ground jumper wire? > > > > 3) Do the strobe/position wires absolutely need to route along the > antenna's > > leading edge even if they otherwise would not CROSS the antenna? Mine can > > run several inches ahead of the antenna, not crossing it. > > > > Please let me know if you need more photos or explanation of my issues. > > Thanks very much! > > > > )_( Dan > > RV-7 N714D > > http://www.rvproject.com > > > ________________________________________________________________________________
From: "'Scott Richardson'" <scott_m_richardson(at)sbcglobal.net>
Subject: GNC-300XL
Date: Jan 28, 2004
Vince, I'll send you a copy. I just emailed Garmin Tech Support and asked them for it and they emailed it to me within the hour. Same for the GTX-327 inst manuals. Scott -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Vincent Welch Subject: AeroElectric-List: GNC-300XL --> Does anyone know where I can get an installation manual for a GNC-300XL? I have checked Garmin's web site but they only list a user's manual for the 300XL. The web site has an installation manual for the 250XL. I need to make up a harness and I don't know if the pin outs are the same. The user's manual does not list pin outs. Vince Welch == direct advertising on the Matronics Forums. == == == ________________________________________________________________________________
Date: Jan 28, 2004
Subject: Re: Lighted Toggle Switches
From: John Schroeder <jschroeder(at)perigee.net>
Hi Dave - Very nice looking panels. Some questions: What do they charge for a panel like one of yours? What do you use for backlighting? If individual lights, what is the spacing and position behind the panels? What kind of sockets for the lights? Many thanks for the information. John Schroeder ________________________________________________________________________________
Date: Jan 28, 2004
From: kempthornes <kempthornes(at)earthlink.net>
Subject: Co ax antenna snap rings
Hi, Where can I get one of these? (The about 0.040 inch snap ring that holds antenna cable plug to the rack for radio, txp etc) K. H. (Hal) Kempthorne RV6-a N7HK - Three trips to OSH now. PRB (El Paso de Robles, CA) ________________________________________________________________________________
From: "David Schaefer" <dschaefer1(at)kc.rr.com>
Subject: Guarded Switches
Date: Jan 28, 2004
What's a good source for 'guarded switches' of the kind you pull out to be able to turn on (or off)? B&C doesn't carry them. The only ones I can find are Honeywell and they're $40-70 per switch! Regards, David Schaefer RV6-A FADEC Finishing Kit ________________________________________________________________________________
Date: Jan 28, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: NKK LED toggle switches
> >Lyle, > I believe that Kevin was referring to a double throw switch. >Charlie Kuss > > > > > >Kevin, > > > >I am puzzled. What kind of switch are you referring to as 'progressive > >on toggle'? I have never heard that used with regard to switches. > > Study the schematic symbols used for the -10 on-on-on and -50 on-on-(on) switches in drawings at: http://www.aeroelectric.com/temp/ProgressiveSW.pdf Also see: http://catalog.sensing.honeywell.com/printfriendly.asp?FAM=tr&PN=2NT1-10 and study the circuitry/operating action. When moving from one extreme to the middle position, only one side of the switch transfers. Continued motion in the opposite extreme transfers the second side, hence the term "progressive" transfer. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Jan 28, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Rochester cht sender.
> > >Bob, > >I haven't posted anything here. Just been lurking and learning. I had >to comment on the "carbine" lamp. I think those were "carbide" lamps. >They generated acetylene to burn for light. Is my foggy recollection >right? yup, got my tongue tangled around my eyeteeth and couldn't see what I was typing. Bob . . . ________________________________________________________________________________
Date: Jan 28, 2004
From: Dave Morris <dave(at)davemorris.com>
Subject: Re: Lighted Toggle Switches now Panels
About $75 to $100 per panel, and that's including all switches and pots. Supply your own electrical components and it's considerably cheaper. I'm planning to put some high intensity LEDs 4 or 5 inches behind the panels facing forward. I have not yet decided on how to mount them, but the panels are designed to be backlit, and they should look really sharp with red LEDs illuminating them. Dave At 03:03 PM 1/28/2004, you wrote: > > >Hi Dave - > >Very nice looking panels. Some questions: > >What do they charge for a panel like one of yours? > >What do you use for backlighting? > >If individual lights, what is the spacing and position behind the panels? > >What kind of sockets for the lights? > >Many thanks for the information. > >John Schroeder > > ________________________________________________________________________________
Date: Jan 28, 2004
From: Charlie Kuss <chaskuss(at)bellsouth.net> LED toggle
Subject: Re: Re: Lighted Toggle Switches was NKK
LED toggle LED toggle Mike, I stopped by my local BOW (Boat Owners Warehouse) this afternoon. I found several of the Carling Technologies LT (lighted toggle) series switches there (re packaged under different brand names) I paid about $13.50 each for these (compared to $9 at my local Carling Dist.) The Bat handles are definitely sturdier. The bright chrome and brushed chrome models have a metal sleeve on them. It is "just" a sleeve, as you said. One thing I noticed was that these switches are Made in Mexico. I also noticed another brand (Hubbell) which are made in the USA. I just did a quick search of their marine catalog. It appears that the selection is rather limited. I'll try to call both Carling and Hubbell tomorrow, if I have time. I'll try to speak to someone in the tech department. I want to find out what switch styles (electrically) are available. I also want to see if Carling has any LT series switches that are USA made. Externally, the Carling LTs look good. No idea what they are like inside. The ones I bought are rated for 15 amps DC. I'd like to ask the tech folks how many cycles these switches are designed for. (MTBF) Charlie > >The broken ones were paddle style, but I believe both >styles are translucent plastic (light pipes). I think >there is a metal sleeve option for the bat style, but >it is just a sleeve (I think). > >Mike > >__________________________________ > > ________________________________________________________________________________
Date: Jan 28, 2004
Subject: Fast on's to make Terminal Blocks
From: Don Boardman <dboardm3(at)twcny.rr.com>
Hi All, Thanks very much for the responses to my Fast-on request. I guess I need to improve my searching skills in the big catalogs! The strips of 5, 90 degree doubles, would be tempting if I was into making larger grounding blocks. I already have a 24 from B&C and I will only need a few grounds on the engine side of the firewall. I am thinking that the single, double male 90's or 45's, would be fine to make up say an 8-10 terminal ground block. Anyone working with the 45's ? I have also been debating how to make connections for situations that typically use the screw type terminal blocks. (Float wiring, etc) WHY NOT USE THE SEPARATE DOUBLE MALE FAST-ON'S RIVETED/FASTENED TO A NONCONDUCTIVE SURFACE TO FABRICATE FAST-ON TERMINAL BLOCKS? This would seem to give the convenience of a terminal block with the desirable connectivity of Fast-ons. Comments ... Don B. ________________________________________________________________________________
From: "Terrence Gardner" <ttandt(at)mindspring.com>
Subject: Trailer Plugs For Wing Root Disconnect
Date: Jan 29, 2004
Weather Pack (Trailer Plugs) fabrication kits are available in various size from longacreracing.com or IrvanSmith.com. You can make up a custom disconnect as described in the AEC using Mil spec wire as opposed to the 9 strand commonly found on these plugs at auto parts stores. These sites have a number of other tools/goodies Terry Gardner RV9a ________________________________________________________________________________
From: Fiveonepw(at)aol.com
Date: Jan 29, 2004
Subject: Re: Fast on's to make Terminal Blocks
In a message dated 1/28/04 10:35:59 PM Central Standard Time, dboardm3(at)twcny.rr.com writes: > I already have a 24 from B&C and I will only need a > few grounds on the engine side of the firewall. > You may wish to consider just taking the grounds through the firewall along with all the other stuff if there are only a few, as you say. I'd suggest this would be a little cleaner with less connections in the engine environment. > > I have also been debating how to make connections for situations that > typically use the screw type terminal blocks. (Float wiring, etc) > You'll need to use ring terminals (PIDG) for the floats and it would probably be a good idea to add a separate ground wire to the sender mounting plate. Another ring terminal with a star washer under one of the screw heads should suffice. I ran the ground wire to a local ground on the fuselage inside the wing root with another ring terminal, FWIW - and by the way, Vans floats & gauges tested amazingly accurate in the 0-10 gal. range- very pleased with that! > WHY NOT USE THE SEPARATE DOUBLE MALE FAST-ON'S RIVETED/FASTENED TO A > NONCONDUCTIVE SURFACE TO FABRICATE FAST-ON TERMINAL BLOCKS? > > This would seem to give the convenience of a terminal block with the > desirable connectivity of Fast-ons. > > Comments ... As a general rule, make as few connections as possible of ANY KIND anywhere in your system- ideally a wire should go directly from a device to a power source or ground. Every joint adds a possible failure point. I'll take reliability over convenience any day! There are plenty of sound ways to reconnect a wire if it needs to be cut... From The PossumWorks in TN Mark Phillips - all-electric RV-6A per Aeroelectric design & EVERYTHING WORKS! 8-) ________________________________________________________________________________
Date: Jan 29, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Guarded Switches
> > >What's a good source for 'guarded switches' of the kind you pull out to be >able to turn on (or off)? B&C doesn't carry them. The only ones I can find >are Honeywell and they're $40-70 per switch! Yup, that's why B&C doesn't carry them. These are indeed a low volume, specialty switch with prices to match. I know of no inexpensive sources of new switches with this feature. Bob . . . ________________________________________________________________________________
From: "Bruce Gray" <Bruce(at)glasair.org>
Subject: Guarded Switches
Date: Jan 29, 2004
Bob's right, my airplane has one, used for gear activation. Do a search on MS24658-23D. Bruce www.glasair.org -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L. Nuckolls, III Subject: Re: AeroElectric-List: Guarded Switches > > >What's a good source for 'guarded switches' of the kind you pull out to be >able to turn on (or off)? B&C doesn't carry them. The only ones I can find >are Honeywell and they're $40-70 per switch! Yup, that's why B&C doesn't carry them. These are indeed a low volume, specialty switch with prices to match. I know of no inexpensive sources of new switches with this feature. Bob . . . ________________________________________________________________________________
Date: Jan 29, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Starter Engaged Light
> > >Bob Nuckolls - > >On Z-14, where is the best place to take power for a "Starter Engaged" >annunciator light? Any place downstream of the starter contactor . . . or from the contactor's "I" terminal if it has one. Be sure to fuse or fuselink this lead AT the POWERED end. Bob . . . ________________________________________________________________________________
Date: Jan 29, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Alternator - Thermocouples
> > > > >After talking to Vans, they said I probably blew the > >voltage regulator by switching off the field that > >disconnected the B-lead at the contactor. Switching > >off field after it has started doesn't stop the > >alternator because it gets field power from the > >B-lead. They said they've been seeing this a lot > >lately on alternators wired per z-24. > > > >Would it be an accurate statement to say that: > >"Turning off the alt field after it has been turned on > >for an internally regulated alternator wired as > >depicted in Z-24 is a death sentence for the > >alternator. An overvolt condition will also open the > >contactor and finish off the alternator for good." > > > >If so, this might be a handy piece of information to > >add to that diagram because it would have saved me > >some trouble. This is the first I've heard of it. Gee, if Van's has seen a rash of these events, it would have been really nice of them to let me know about it. I'm looking into this. Watch this space. Bob . . . ________________________________________________________________________________
Date: Jan 29, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Wiring PTT button
> >Bob, these are great explanations and very helpful. You should get some >kind of special acknowledgement for your work supporting homebuilders. >--Kent A. But I DO get rewarded . . . OBAM aircraft are coming on line in ever increasing numbers unencumbered by no-value-added assistance by those-who-know-more-about-airplanes-than-we-do. Better yet, OBAM aircraft performance and return on investment stands head and shoulders above stuff pushed off the assembly lines. For me, this is many times more satisfying than any placard on the wall or trophy on the shelf . . . but thank you for thinking of me! Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
From: Speedy11(at)aol.com
Date: Jan 29, 2004
Subject: Re: AeroElectric-List Digest: 41 Msgs - 01/28/04
In a message dated 1/29/04 2:58:55 AM Eastern Standard Time, aeroelectric-list-digest(at)matronics.com writes: << I am leaning more toward the bat (aka Snapkap in the Carling Catalog) style handles as I feel that they would be more durable. >> Charlie, The Carling web site, in regard to the SnapKap switches says, "The LT-Series toggle switches are AC rated illuminated toggle switches featuring a three-color lighting sequence from a single lamp." I understood that we shouldn't use AC switches because when used with DC power the contacts burn slightly each time they are thrown thus building up over time and causing long term trouble. Is it okay to use AC switches? Stan Sutterfield Tampa ________________________________________________________________________________
Date: Jan 29, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Shielded sensor wires
> >Terry, > >The thermocouple wire can be connected with crimped butt splices. However >note that in my opinion, which should be taken with a grain of salt, >soldering and heat shrink makes better connections. > >Regards, >Trampas Stern It's true, and contrary to what I wrote in the 'Connection that thermocouple wire can be soft-soldered with readily available tin-lead solder with the right kind of flux. I'm considered doing a comic-book on this technique. Given my earlier (20+ years ago) disappointing experiences with soft solder, it's important that whatever we recommend has a high-order probability of success for the neophyte builder. In the mean time, techniques that get gas-tight grips on thermocouple wires like silver solder, PIDG crimps, 4-quad d-sub crimps, etc. are attractive for their lack of process sensitivity. Bob . . . ________________________________________________________________________________
Date: Jan 29, 2004
From: Paul <pwilson(at)climber.org>
Subject: Re: Guarded Switches
Bought a simple on-off from John Deere for my tractor. It is a pull to move type. Dont have the tractor so I cannot look up the brand. It was used to control the PTO. BTW, Auto Zone has flip covers in various colors to protect toggles. They have a simple attachment that is held by the switch. Paul > > >> >> >>What's a good source for 'guarded switches' of the kind you pull out to be >>able to turn on (or off)? B&C doesn't carry them. The only ones I can find >>are Honeywell and they're $40-70 per switch! > > Yup, that's why B&C doesn't carry them. These are indeed a low > volume, specialty switch with prices to match. > > I know of no inexpensive sources of new switches with > this feature. > > Bob . . . -- ________________________________________________________________________________
From: "Neville Kilford" <nkilford(at)etravel.org>
Subject: Re: Starter Engaged Light
Date: Jan 29, 2004
Bob, Why is it necessary to fuse the warning light (not an accusation, by the way)? I'm thinking that the light would only be powered when the contactor is engaged -- the same as the starter motor, which isn't protected. TIA. Nev -- Jodel D150 in progress UK ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: Starter Engaged Light > > > > > > >Bob Nuckolls - > > > >On Z-14, where is the best place to take power for a "Starter Engaged" > >annunciator light? > > Any place downstream of the starter contactor . . . or from the > contactor's "I" terminal if it has one. Be sure to fuse or > fuselink this lead AT the POWERED end. > > Bob . . . > ________________________________________________________________________________
From: F1Rocket(at)comcast.net
Subject: Re: Starter Engaged Light
Date: Jan 29, 2004
What's the risk if power for the light is taken from the fat terminal on the contactor that goes to the starter, as long as it is fuselinked? Randy http://f1rocket.home.comcast.net/ > >Bob Nuckolls - > > > >On Z-14, where is the best place to take power for a "Starter Engaged" > >annunciator light? > > Any place downstream of the starter contactor . . . or from the > contactor's "I" terminal if it has one. Be sure to fuse or > fuselink this lead AT the POWERED end. > > Bob . . . > ________________________________________________________________________________
Date: Jan 29, 2004
Subject: Re: Lighted Toggle Switches now Panels
From: John Schroeder <jschroeder(at)perigee.net>
Dave - Thanks for the info. I'm planning on using LED's. The engraved panels will be over an aluminum panel of the same size. Looks like we'll have to experiment on the size and placement of the LED's. Drill holes in the aluminum plate and pot the LED's into the holes? Do you know of any good mounting hardware for LED's? Might be able to adapt Bob's roll-your-own kind that he has posted on his site. John ________________________________________________________________________________
Date: Jan 29, 2004
Subject: Ground Power Plug
From: John Schroeder <jschroeder(at)perigee.net>
Hi Bob - We're using Z-14 on a Lancair ES (batteries in the rear). We made and installed your "Piper Style" external power receptacle. You show a diode installed on the sensing pin in your diagrams that use the "Cessna Style" receptacle. It does not appear that one needs or can use a diode in a polarity sensing circuit for the Piper receptacle. Correct? If you need one, where would it go? Thanks, John Schroeder -- ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: Guarded Switches // D-sub dust covers
Date: Jan 29, 2004
Prics and availability depends on needing a large body switch with 10-20amp rating. Lots of small body switches with 5-6 amp contacts (and the bat handle is full size so looks are close to the same) are available at a reasonable cost. I have used them for many, many years with no problems on DC applications. Available in SPDT, DPDT, 3PDT, 4PDT with pricing from $6 to $15 depending on supplier, # poles, and MFGR. Mine have available screw on caps in RED or Aluminum color. Use the following link with the mfgrs part # to find stock. www.findchips.com C&K try "7103k" for the part search without the "" ITT try "7203K NKK try "M2012LL1W01",find the catalog page for different poles etc Mouser page 831 for example Alco try "MTL106" NOT seen by me but Alco lists a DP3T (ON-ON-ON) switch. MTL 406PA (Mouser has stock) I have not tried all of the above (using find chips but did try many) and obtained the MFGR's part # from the following catalogs: Digi-Key, Mouser, Newark, Allied, all list this type of switch and use of find chips link provides a near instant stock and price comparison. DUST CAPS FOR D-SUB CONNECTORS Some time back there was a request for dust caps for the D-Sub connectors. All of the above distributors list them in low quanity and price in various sizes. Paul ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: Guarded Switches > > > > > > > >What's a good source for 'guarded switches' of the kind you pull out to be > >able to turn on (or off)? B&C doesn't carry them. The only ones I can find > >are Honeywell and they're $40-70 per switch! > > Yup, that's why B&C doesn't carry them. These are indeed a low > volume, specialty switch with prices to match. > > I know of no inexpensive sources of new switches with > this feature. > > Bob . . . > > ________________________________________________________________________________
Date: Jan 29, 2004
Subject: Re: Starter Engaged Light
From: John Schroeder <jschroeder(at)perigee.net>
Randy - What is fuselinked? The fat starter wire? The wire going back to the light? I read Bob's response as fuzing or fuzelinking the wire back to the light. I do not believe that the starter has any fuzing in the fatwire from the contactor to the starter motor. Cheers, John > > What's the risk if power for the light is taken from the fat terminal on > the contactor that goes to the starter, as long as it is fuselinked? > > Randy > http://f1rocket.home.comcast.net/ > >> >Bob Nuckolls - >> > >> >On Z-14, where is the best place to take power for a "Starter Engaged" >> >annunciator light? >> >> Any place downstream of the starter contactor . . . or from the >> contactor's "I" terminal if it has one. Be sure to fuse or >> fuselink this lead AT the POWERED end. >> >> Bob . . . ________________________________________________________________________________
Date: Jan 29, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Starter Engaged Light
> >What's the risk if power for the light is taken from the fat terminal on >the contactor that goes to the starter, as long as it is fuselinked? none at all. Bob . . . ________________________________________________________________________________
Date: Jan 29, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Switch behavior
There's more to switch behavior than pricing, mil-spec, UL approved, etc., etc. While working a task for RAC, I've been discovering the effects of contact bounce on relays and switches. Just took these traces on the bench comparing transition and bounce characteristics of two products with big differences in perceived "quality". It's bounce characteristics of Microswitch products that that uncovered a design deficiency in the ov protection system of LR series regulators at RAC a few years ago. When it gets down to the simple-ideas, one can encounter some pretty profound differences that may or may not show up in the advertising hype or published specifications. See: http://www.aeroelectric.com/articles/bounce.pdf Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Jan 29, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> 01/28/04
Subject: Re: AeroElectric-List Digest: 41 Msgs -
01/28/04 01/28/04 > >In a message dated 1/29/04 2:58:55 AM Eastern Standard Time, >aeroelectric-list-digest(at)matronics.com writes: > ><< I am leaning more toward the bat (aka Snapkap in the Carling Catalog) >style handles > as I feel that they would be more durable. >> > >Charlie, >The Carling web site, in regard to the SnapKap switches says, "The LT-Series >toggle switches are AC rated illuminated toggle switches featuring a >three-color lighting sequence from a single lamp." I understood that we >shouldn't use >AC switches because when used with DC power the contacts burn slightly each >time they are thrown thus building up over time and causing long term >trouble. >Is it okay to use AC switches? See http://www.aeroelectric.com/articles/swtchrat.pdf Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Jan 29, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Starter Engaged Light
> > >Bob, > >Why is it necessary to fuse the warning light (not an accusation, by the >way)? I'm thinking that the light would only be powered when the contactor >is engaged -- the same as the starter motor, which isn't protected. you aren't going to burn a 2 or 4AWG wire . . . you'll burn a 22AWG lamp wire in seconds. When we owned the airport at Benton, had a mechanic attempt to crank an engine without attaching the crankcase to firewall jumper . . . did it twice on different airplanes. Made for lots of smoke in a couple of seconds and lots of work to replace wires. I didn't give him a third crack at it. General rule of thumb is any wire NOT part of fat feeders for alternator, battery or cranking motors that is 6" or longer get protected. That's why you see fusible links in fuesblock-to-regulator feedwire our z-figures. Bob . . . ________________________________________________________________________________
Subject: Re: Guarded Switches // D-sub dust covers
From: John Schroeder <jschroeder(at)perigee.net>
Date: Jan 29, 2004
Paul - That website is fabulous. Thanks for sharing it with us. John > Use the following link with the mfgrs part # to find stock. > > www.findchips.com ________________________________________________________________________________
Subject: External Power Receptacle
From: John Schroeder <jschroeder(at)perigee.net>
Date: Jan 29, 2004
Bob Nuckolls - Disregard my request about the diode in the Z-14/External Power diagram. I found one of your AutoCAD drawings in your "Weekend Seminars" wirebook that shows the wiring for the "Piper" receptacle. It does not show a diode in the circuit. I also saw the fuzing and takeoff point for the "Starter Engaged" light in another drawing. It comes off the starter side of the starter solenoid. Thanks, John -- ________________________________________________________________________________
Date: Jan 29, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Fig Z-16 Rotax 912/914 System
> > >Bob et.al. > >I feel deprived not being able to attend one of your seminars owing to >where I live. I am therefore grateful for the opportunity to tap into >the combined wisdom available on this list. > >In my endeavour to more fully understand the principles being applied >and to try to gain more confidence in my ability to interpret the >diagrams, I would be most obliged if you or others could help me with >the following queries - ALL in respect of Fig Z-16 Rotax 912/914 >System. I have a plain vanilla Rotax 912 engine and a Europa aircraft >(composite) with no bells or whistles and will be flying only day VFR. > >My queries > >1 Reason for the fusible link in series with the 5A CB in the line >from the main bus to terminal 5 on S1, Master Switch? The wire from bus to breaker is more than 6" long and has smoke-risk due to it's length an small size. A fuse won't protect it because we're trying to open a breaker downstream. Some 5A breakers are so slow that they'll open a 30A fuse upstream. The fusible link provides a robust (slow acting) protection of that wire. >2 Reason for the fusible link as opposed to an inline fuse in >series with the Alternator Warn light? See above. >3 As I see the Alt Warn light in this circuit, the warning it >provides is that the alternator is "off line" rather than that it is not >charging. Correct. Active notification of low voltage is the ulitmate warning light. > If I also connect another warning light between terminal 4 of >the Master Switch and terminal "L" on the regulator (or "L" and "C" on >the regulator), will this light illuminate when the engine is not >running with the Master Sw turned fully on and extinguish as the >alternator voltage rises after start-up? Low voltage warning would be better . . . it catches low alternator output for ANY reason. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
From: "Ken Brooks" <kenbrooks(at)charter.net>
Subject: Another option for Van's ABS air vents
Date: Jan 29, 2004
While looking at the Aircraft Simulators site for backlit panel switches, etc., I noticed they also had some attractive eyeball vents (ABS plastic) that are smaller than the large ones that Van's sells. Thought others might be interested. Cost is $25 ea. http://www.aircraftsimulators.com/litevent.html Ken Brooks Roscoe, IL Mired down with the canopy ________________________________________________________________________________
From: "Kenneth Gresham" <kgresham(at)mtco.com>
Subject: Quick connects
Date: Jan 29, 2004
Does anyone have a suggestion for a simple quick connection for five or more wires. This is for an electric trim tab servo and I would like to easily remove for repair. ________________________________________________________________________________
From: "Alex Peterson" <alexpeterson(at)usjet.net>
Subject: Quick connects
Date: Jan 29, 2004
> Does anyone have a suggestion for a simple quick connection > for five or more wires. This is for an electric trim tab > servo and I would like to easily remove for repair. Someone suggested a while back using high quality R/C aircraft connectors. Sounds good to me. Alex Peterson Maple Grove, MN RV6-A N66AP 434 hours www.usfamily.net/web/alexpeterson ________________________________________________________________________________
From: "Randy Pflanzer" <f1rocket(at)comcast.net>
Subject: Re: Starter Engaged Light
Date: Jan 29, 2004
That means to install a "fusible link" as a type of protection at the power end of a circuit. It functions like a fuse or circuit breaker. You can buy kits from B&C. Essentially, all it is ...is a smaller gauge wire than the wire it is protecting, covered in a fireproof sheath. If the circuit gets an overload, this short piece of wire will get red hot and break before the wire in the circuit fries. The sheath keeps it from melting anything around it. Sort of a "poor man's" fuse. Very ingenious, cheap, and simple to install. ----- Original Message ----- From: "John Schroeder" <jschroeder(at)perigee.net> Subject: Re: AeroElectric-List: Starter Engaged Light > > Randy - > > What is fuselinked? The fat starter wire? The wire going back to the light? > > I read Bob's response as fuzing or fuzelinking the wire back to the light. > I do not believe that the starter has any fuzing in the fatwire from the > contactor to the starter motor. > > Cheers, > > John > > > > > > What's the risk if power for the light is taken from the fat terminal on > > the contactor that goes to the starter, as long as it is fuselinked? > > > > Randy > > http://f1rocket.home.comcast.net/ > > > >> >Bob Nuckolls - > >> > > >> >On Z-14, where is the best place to take power for a "Starter Engaged" > >> >annunciator light? > >> > >> Any place downstream of the starter contactor . . . or from the > >> contactor's "I" terminal if it has one. Be sure to fuse or > >> fuselink this lead AT the POWERED end. > >> > >> Bob . . . > > ________________________________________________________________________________
Subject: RE: Quick connects
Date: Jan 29, 2004
From: "Condrey, Bob (US SSA)" <bob.condrey(at)baesystems.com>
Here's Bob's suggestion: http://www.aeroelectric.com/articles/macservo/macservo.html ________________________________________________________________________________
From: "Larry Bowen" <Larry(at)BowenAero.com>
Subject: Quick connects
Date: Jan 29, 2004
I did it like this: http://bowenaero.com/copper/displayimage.php?album=search&cat=0&pos=0 - Larry Bowen Larry(at)BowenAero.com http://BowenAero.com > -----Original Message----- > From: Kenneth Gresham [mailto:kgresham(at)mtco.com] > Sent: Thursday, January 29, 2004 7:03 PM > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Quick connects > > > --> > > Does anyone have a suggestion for a simple quick connection > for five or more wires. This is for an electric trim tab > servo and I would like to easily remove for repair. ________________________________________________________________________________
Subject: Re: Quick connects
From: John Schroeder <jschroeder(at)perigee.net>
Date: Jan 29, 2004
See Bob Nuckolls How-to paper on his website. It adapts a DB9 connector for trim tab servos. If you can't find it, let me know and I'll email you a copy of it. John wrote: > > > Does anyone have a suggestion for a simple quick connection for five or > more wires. This is for an electric trim tab servo and I would like to > easily remove for repair. > > -- ________________________________________________________________________________
Date: Jan 29, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Co ax antenna snap rings
> > >Hi, > >Where can I get one of these? > >(The about 0.040 inch snap ring that holds antenna cable plug to the rack >for radio, txp etc) Check out the assortment of special hardware in any REAL hardware store. ACE Hardware is one. They have drawers with little bins containing assortments of specialty hardware. Measure the o.d. of the groove in the connector and see if the hardware store has a snap ring very close to the size you need. Bob . . . ________________________________________________________________________________
From: "Darwin N. Barrie" <ktlkrn(at)cox.net>
Subject: Re: Quick connects
Date: Jan 29, 2004
Deans 5 pin gold connectors available from www.radicalrc.com. Small, light and a very solid connect. Darwin N. Barrie Chandler AZ ----- Original Message ----- From: "Alex Peterson" <alexpeterson(at)usjet.net> Subject: RE: AeroElectric-List: Quick connects > > > Does anyone have a suggestion for a simple quick connection > > for five or more wires. This is for an electric trim tab > > servo and I would like to easily remove for repair. > > Someone suggested a while back using high quality R/C aircraft > connectors. Sounds good to me. > > Alex Peterson > Maple Grove, MN > RV6-A N66AP 434 hours > www.usfamily.net/web/alexpeterson > > ________________________________________________________________________________
From: N67BT(at)aol.com
Date: Jan 29, 2004
Subject: Re: Quick connects
I bought a the Hirose mini circular connector from Digikey. They are very small, easy to attach, locking, not real expensive, and sealed. I haven't installed it yet but it looks perfect for the elevator trim to 5 wire Ray Allen cable. There is a photo at the following site. http://www.hirose.com/ ________________________________________________________________________________
Date: Jan 29, 2004
From: richard(at)riley.net
Subject: CNX-80 FS
I have one last CNX-80 for sale, new with full warrantee, $8750, doesn't have to be installed by a dealer. ________________________________________________________________________________
From: "Kingsley Hurst" <khurst(at)taroom.qld.gov.au>
Subject: Fig Z-16 Rotax 912/914 System
Date: Jan 30, 2004
>1 Reason for the fusible link in series with the 5A CB in the line >from the main bus to terminal 5 on S1, Master Switch? The wire from bus to breaker is more than 6" long and has smoke-risk due to it's length an small size. A fuse won't protect it because we're trying to open a breaker downstream. Some 5A breakers are so slow that they'll open a 30A fuse upstream. The fusible link provides a robust (slow acting) protection of that wire. Thank you for the clarification Bob, much appreciated. Kingsley Hurst ________________________________________________________________________________
From: "Troy Scott" <tscott1217(at)bellsouth.net>
Subject: several questions
Date: Jan 30, 2004
Bob Nuckolls et al, Today I was at Home Depot "Electrical Solder" described as "lead free", 95% tin/5% antimony. After looking at several brands, I realized that ALL the "electronics grade" solder there was "lead free". Is this because of new government guidelines or some lawsuit problem? Is this solder good for our purposes? Bob, I've ordered the circuit board for your Audio Isolation Amplifier. I'd like to use it to eliminate the need for an audio panel. I'll have an SL30 Nav-Com, another Com- only radio and an RST Marker Beacon Receiver. I plan to just use the volume controls to select what I want to hear. I want to utilize the internal intercom in the SL30. Do you foresee any problems with this audio setup? Have you considered a way to make the stereo input "auto mute" in favor of communications from ATC? In your book I read about the method for trimming the quarter-wave dipole antennas like I have installed in my Glasair. You mention a "through-line wattmeter". I haven't been able to find out anything about this device. Can you elaborate? I've been planning to mount my transponder antenna on an aluminum inspection cover. I read in your book that the ground plane diameter should be twice the element length. Does this mean EXACTLY twice the length of the element? Of is a little bigger OK? I see this style antenna mounted on the bottom of aluminum airplanes where the whole airplane, or at least the whole panel is the ground plane.... Anyway, the round aluminum inspection panel where I'd planned to mount it is 6 5/8" in diameter. I also have another inspection panel available that is 5 5/8". Regards, Troy Scott tscott1217(at)bellsouth.net ________________________________________________________________________________
From: "Dan Checkoway" <dan(at)rvproject.com>
Subject: Re: Quick connects
Date: Jan 29, 2004
All of the suggestions given are good ones. The problem with using a connector, though, is that if you need to remove the elevator, you'll have to remove the connector...not convenient. (at least that's the way it is on an RV...just a small round hole for the wire to pass through the elevator spar) Here's what I did instead: http://www.rvproject.com/20040124.html I used D-sub pins and sockets, and that's it. No connector body to worry about. Heat shrink over each pin/socket pair, and then heat shrink over the bundle. Need to remove the servo, cut the heat shrink, pull the pins/sockets apart. Need to remove the elevator? Same deal, and there's no fat connector to worry about. Best of luck, )_( Dan RV-7 N714D http://www.rvproject.com ----- Original Message ----- From: "Kenneth Gresham" <kgresham(at)mtco.com> Subject: AeroElectric-List: Quick connects > > Does anyone have a suggestion for a simple quick connection for five or more wires. This is for an electric trim tab servo and I would like to easily remove for repair. > > ________________________________________________________________________________
From: "Michel RIAZUELO" <mt.riazuelo(at)wanadoo.fr>
Subject: Re: Fig Z-16 Rotax 912/914 System
Date: Jan 30, 2004
Bob, You answered to Kinsley : > The wire from bus to breaker is more than 6" long and has > smoke-risk due to it's length an small size. On my MCR SPORTSTER (ROTAX 912 and Z-16), the line from terminal 5 on S1, Master Switch and the 5A CB is 2" long. The line from the 5A CB and the MAIN BUS is 4" long. Can I use 22AWG for the two line, without FuseLink ? I have sawn on some aircraft silicone sleeves to "protect" FastOn terminals. I use B&C ones. I never read anything about that on the Aeroelectric list. Usefull or useless ? Thanks again for the job you do for us. Michel RIAZUELO MCR SPORTSTER ________________________________________________________________________________
From: "Gilles Thesee" <Gilles.Thesee@ac-grenoble.fr>
Subject: Re: Fig Z-16 Rotax 912/914 System
Date: Jan 30, 2004
> I have sawn on some aircraft silicone sleeves to "protect" FastOn terminals. I use B&C ones. I never read anything about that on the Aeroelectric list. Usefull or useless ? > Hi Michel and all, In my opinion, "Faston protection" is not a big issue. We didn't bother with it. Regards, Gilles MCR 4S & Rotax 914 Cooling ducts definition in progress ________________________________________________________________________________
Date: Jan 30, 2004
From: Charlie Kuss <chaskuss(at)bellsouth.net> 01/28/04
Subject: Re: AeroElectric-List Digest: 41 Msgs -
01/28/04 01/28/04 Bob states in the AeroElectric book that the 120 AC volt rating (for amps) is equivalent for 12 volts DC. Charlie > >In a message dated 1/29/04 2:58:55 AM Eastern Standard Time, >aeroelectric-list-digest(at)matronics.com writes: > ><< I am leaning more toward the bat (aka Snapkap in the Carling Catalog) >style handles > as I feel that they would be more durable. >> > >Charlie, >The Carling web site, in regard to the SnapKap switches says, "The LT-Series >toggle switches are AC rated illuminated toggle switches featuring a >three-color lighting sequence from a single lamp." I understood that we shouldn't use >AC switches because when used with DC power the contacts burn slightly each >time they are thrown thus building up over time and causing long term trouble. >Is it okay to use AC switches? >Stan Sutterfield >Tampa > > ________________________________________________________________________________
Date: Jan 30, 2004
From: Dave Morris <dave(at)davemorris.com>
Subject: Re: Lighted Toggle Switches now Panels
I haven't planned anything fancy, since they will be hidden behind the panel and hopefully have a very long lifetime. My whole airplane is made of epoxy, maybe I'll just drill a little hole in the fiberglass panel, stick the LED into the hole and glue it in place with 2 minute stuff. I'm thinking one LED aimed at the top back side and one at the bottom should give plenty of illumination. Dave > > >Dave - > >Thanks for the info. I'm planning on using LED's. The engraved panels will >be over an aluminum panel of the same size. Looks like we'll have to >experiment on the size and placement of the LED's. Drill holes in the >aluminum plate and pot the LED's into the holes? Do you know of any good >mounting hardware for LED's? Might be able to adapt Bob's roll-your-own >kind that he has posted on his site. > >John > > Dave Morris ________________________________________________________________________________
Date: Jan 30, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: several questions
> > >Bob Nuckolls et al, > >Today I was at Home Depot "Electrical Solder" described as "lead free", 95% >tin/5% antimony. After looking at several brands, I realized that ALL the >"electronics grade" solder there was "lead free". Is this because of new >government guidelines or some lawsuit problem? Is this solder good for our >purposes? I don't know. We're all aware of the ever increasing shrillness of voices decrying this gawdawful pollutant and that stress on the environment with all too many politicians ready to mount up with their white hats on and come charging over the hill to our "rescue". Problem is that there's so much BS stirred in with the real science that it's difficult to sort out the pieces. Solders in hardware stores for copper plumbing have been lead-free for a lot of years. Yeah, I can see some basic logic in that . . . we DO drink water that flows past the joints. You might poke around on the 'net and see what the rumblings are about non-lead solders for electronics. Not having any good information one way or the other, I'd stick with what we know works VERY well, good ol' 60/40 or 63/37 tin-lead with a good flux. Get a name brand like Kester or Multicore. >Bob, I've ordered the circuit board for your Audio Isolation Amplifier. I'd >like to use it to eliminate the need for an audio panel. I'll have an SL30 >Nav-Com, another Com- only radio and an RST Marker Beacon Receiver. I plan >to just use the volume controls to select what I want to hear. I want to >utilize the internal intercom in the SL30. Do you foresee any problems with >this audio setup? Lots of folks have been doing this. >Have you considered a way to make the stereo input "auto >mute" in favor of communications from ATC? There are a ton of features we could build into an audio system . . . but that means going toe-to-toe with folks who have been doing that for years and doing it rather well. I prefer to offer goodies you can't get anywhere else -OR- item that can blow away some piece of junk already in the markeplace. >In your book I read about the method for trimming the quarter-wave dipole >antennas like I have installed in my Glasair. You mention a "through-line >wattmeter". I haven't been able to find out anything about this device. >Can you elaborate? Here's the gold standard in thru-line wattmeters. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3074027135&category=48701 You also have to have a "slug" that covers the frequency and power range of interest. They're kinda pricey for a one time need. See if you can borrow/rent one from a local two-way radio shop . . . or pay one of their techs to come out and do a look-see on your antennas. Here's my favorite antenna tool. http://www.mfjenterprises.com/products.php?prodid=MFJ-259B >I've been planning to mount my transponder antenna on an aluminum inspection >cover. I read in your book that the ground plane diameter should be twice >the element length. Does this mean EXACTLY twice the length of the element? >Of is a little bigger OK? I see this style antenna mounted on the bottom of >aluminum airplanes where the whole airplane, or at least the whole panel is >the ground plane.... Anyway, the round aluminum inspection panel where I'd >planned to mount it is 6 5/8" in diameter. I also have another inspection >panel available that is 5 5/8". The purists will debate at length and with enthusiasm as to the effectiveness of finely tuned antennas. Fact is that from an airplane, everything you talk/listen to is line-of-sight . . . a wet string would get you 90% coverage of your area of interest. When it's EASY to be precise, why not? If convenience drives you to consider the inspection plates, go ahead. Nobody will know the difference but you . . and that only because you took the time to worry about it a little. Bob . . . ________________________________________________________________________________
Subject: Alternator Field Wiring
From: John Schroeder <jschroeder(at)perigee.net>
Date: Jan 30, 2004
Bob - Z-14. In various wirebooks I see AWG 20 and AWG 18 as wire to pin 6 (bus voltage) on the LR-3's. For a 70 amp main and 20 amp secondary alternator which combo is best: 24AWG Fuse link and 20 AWG? or 22 AWG fuse link and 18 AWG? Many Thanks, John Schroeder. -- ________________________________________________________________________________
Date: Jan 30, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Alternator Field Wiring
> > >Bob - > >Z-14. In various wirebooks I see AWG 20 and AWG 18 as wire to pin 6 (bus >voltage) on the LR-3's. For a 70 amp main and 20 amp secondary alternator >which combo is best: > >24AWG Fuse link and 20 AWG? >or >22 AWG fuse link and 18 AWG? If the wire between bus and regulator is long (say over 6 feet) we'd like to minimize resistance . . . I'd go 18/22 just for grins. Otherwise 20/24 is fine. Bob . . . ________________________________________________________________________________
Date: Jan 30, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Fig Z-16 Rotax 912/914 System
> > >Bob, > >You answered to Kinsley : > > > The wire from bus to breaker is more than 6" long and has > > smoke-risk due to it's length an small size. > >On my MCR SPORTSTER (ROTAX 912 and Z-16), the line from terminal 5 on S1, >Master Switch and the 5A CB is 2" long. The line from the 5A CB and the >MAIN BUS is 4" long. >Can I use 22AWG for the two line, without FuseLink ? Sure >I have seen some aircraft silicone sleeves to "protect" FastOn terminals. >I use B&C ones. I never read anything about that on the Aeroelectric list. >Usefull or useless ? Looks purty . . . your option. I think heatshrink would look better and would stay in place better. >Thanks again for the job you do for us. My pleasure sir. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
From: KITFOXZ(at)aol.com
Date: Jan 31, 2004
Subject: Re: Quick connects
In a message dated 1/30/2004 3:01:52 AM Eastern Standard Time, dan(at)rvproject.com writes: All of the suggestions given are good ones. The problem with using a connector, though, is that if you need to remove the elevator, you'll have to remove the connector...not convenient. (at least that's the way it is on an RV...just a small round hole for the wire to pass through the elevator spar) Here's what I did instead: http://www.rvproject.com/20040124.html Hello Dan, As an electronics professional, hobbyist and aviation nut, it is good to see someone else finding some clever short cuts that I thought I owned in the privacy of my shop 8 ). Truthfully, many of us have used this "cheapest connector" idea for some years. But, it is more than just cheap as you have pointed out. It is a very small, reliable connection technique and if you stagger the connection pins a bit, there is no smaller total diameter method that I know of to connect a few wires in line for future easy disconnect. Another advantage is the ease in making the actual connections-one at a time in free space-not fighting to get to one pin in a nest of several. I also like "Dean's Connectors" as someone else mentioned. Dean's connectors are small, light, have very good contact pressures but they are a chore to solder the wires to if you are our age. (let's just say over 40) The Dean's connectors also suffer a diameter penalty in areas where that is an issue. Back to D-sub pins again, I have epoxied female pins just inside of small electronic goodies over the years. You drill a hole in the plastic shell of whatever device and cement the female pin inside. Cables of just a few wires with male pins connected and heat shrunk shielded are "plugged" in. Two holes in the side of a plastic cased goody backed up with female pins can be jumpered together with a "U" shaped pin where a function may be "jumpered" "out" or "in" for different functions. John P. Marzluf Columbus, Ohio Kitfox Outback (out back in the garage) ________________________________________________________________________________
Date: Jan 31, 2004
From: klehman(at)albedo.net
Subject: ov protection for internal v.r. alternators
This is one of my remaining concerns as well. I'm using a different less common small alternator and the internal v.r. for it happens to be a bit expensive. I've seen several cautions regarding the requirement to have a battery in the circuit to stabilize alternators. If it is unstable, I can imagine excess voltage damaging the internal v.r. after the load is disconnected. That makes me think that a switch (Bat Master/Alt.) to allow disconnecting the ov relay while the engine is running may not be a good idea. Likewise my concern about ov protection unless I can be quite confident that no random erroneous disconnects are going to occur. A real ov event is not a concern of course as in that event the internal v.r. would almost certainly be already toasted. Ken >>>After talking to Vans, they said I probably blew the >>>voltage regulator by switching off the field that >>>disconnected the B-lead at the contactor. Switching >>>off field after it has started doesn't stop the >>>alternator because it gets field power from the >>>B-lead. They said they've been seeing this a lot >>>lately on alternators wired per z-24. >>> >>>Would it be an accurate statement to say that: >>>"Turning off the alt field after it has been turned on >>>for an internally regulated alternator wired as >>>depicted in Z-24 is a death sentence for the >>>alternator. An overvolt condition will also open the >>>contactor and finish off the alternator for good." >>> >>>If so, this might be a handy piece of information to >>>add to that diagram because it would have saved me >>>some trouble. > > This is the first I've heard of it. Gee, if Van's > has seen a rash of these events, it would have been > really nice of them to let me know about it. > > I'm looking into this. Watch this space. > > Bob . . . ________________________________________________________________________________
Date: Jan 31, 2004
From: Clay R <clayr_55(at)yahoo.com>
Subject: re: ov protection for internal v.r. alternators
Now I see the following warning on Vans web site on the alternator page. (I think this was added this week) Warning! The internally regulated 60 ampere alternator should not be used with overvoltage protection systems. If you open the charging circuit while it is in operation, it will destroy the regulator. -Clay __________________________________ ________________________________________________________________________________
From: "Fergus Kyle" <VE3LVO(at)rac.ca>
Subject: Power supplies
Date: Jan 31, 2004
Bob, " Unless your strobe supply has been sitting on the shelf for years, that time honored slow crank-up procedure isn't really useful. It was most useful 30 years ago before electrolytic capacitor technology really came of age . . ." Yeah, understood - 'cept the book that came with it says so, so maybe I've been harbouring this since '97. Of course as you have so clearly noted previously, manufacturers aren't ALWAYS right............. Cheers, Ferg ________________________________________________________________________________
From: "Ned Thomas" <315(at)cox.net>
Subject: Re: re: ov protection for internal v.r. alternators
Date: Jan 31, 2004
For what it is worth, I had an internally regulated alternator on my RV6A. I had an Overvoltage occur and had no way to shut it off except land and turn off the engine. When I smelled the battery acid cooking out I was quite concerned. I was able to land before ruining the battery but even tho I immediately turned off the master when I found the voltmeter reading high, I did find that one of my strobes had fried. After this happened I installled the OV protection recommended by Bob. In the event you do encounter an OV situation you must be able to isolate the alternator. I was lucky, the battery could have blown up... ----- Original Message ----- From: "Clay R" <clayr_55(at)yahoo.com> Subject: AeroElectric-List: re: ov protection for internal v.r. alternators > > Now I see the following warning on Vans web site on > the alternator page. (I think this was added this > week) > > Warning! > The internally regulated 60 ampere alternator should > not be used with overvoltage protection systems. If > you open the charging circuit while it is in > operation, it will destroy the regulator. > > -Clay > > __________________________________ > > ________________________________________________________________________________
Date: Jan 31, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Quick connects
> >In a message dated 1/30/2004 3:01:52 AM Eastern Standard Time, >dan(at)rvproject.com writes: >All of the suggestions given are good ones. The problem with using a >connector, though, is that if you need to remove the elevator, you'll have >to remove the connector...not convenient. (at least that's the way it is on >an RV...just a small round hole for the wire to pass through the elevator >spar) > >Here's what I did instead: > >http://www.rvproject.com/20040124.html >Hello Dan, > >As an electronics professional, hobbyist and aviation nut, it is good to see >someone else finding some clever short cuts that I thought I owned in the >privacy of my shop 8 >). Truthfully, many of us have used this "cheapest >connector" idea for some years. But, it is more than just cheap as you >have pointed >out. It is a very small, reliable connection technique and if you stagger >the >connection pins a bit, there is no smaller total diameter method that I >know of >to connect a few wires in line for future easy disconnect. > >Another advantage is the ease in making the actual connections-one at a time >in free space-not fighting to get to one pin in a nest of several. I also >like "Dean's Connectors" as someone else mentioned. Dean's connectors are >small, >light, have very good contact pressures but they are a chore to solder the >wires to if you are our age. (let's just say over 40) The Dean's connectors >also suffer a diameter penalty in areas where that is an issue. > >Back to D-sub pins again, I have epoxied female pins just inside of small >electronic goodies over the years. You drill a hole in the plastic shell of >whatever device and cement the female pin inside. Cables of just a few >wires with >male pins connected and heat shrunk shielded are "plugged" in. Two holes in >the side of a plastic cased goody backed up with female pins can be jumpered >together with a "U" shaped pin where a function may be "jumpered" "out" or >"in" >for different functions. Just one caution. When examining connectors classically used in aircraft, one can see attention paid to protection of the pin-socket joints and making sure that tension on the wires won't open a joint. Unless you're working with butt-splices, knife splices, and soldered joints, etc. where resistance to tension are inherent in the technology, make sure your quest for miniaturization and/or convenience doesn't increased potential for failures that could make you uncomfortable. I offered the d-sub pins and heat shrink for compact thermocouple splicing . . . but then opening that joint in flight doesn't affect flight system performance. I don't intend to splash cold water on any innovative techniques . . . only a word to the wise to think through the failure mode effects analysis for any out-of-the-ordinary usage of parts. Question: do you KNOW how difficult it is to handle the airplane with a pitch trim actuator stuck at either extreme? Of course this question goes to reliability of ALL components in the pitch trim system, not just novel approaches to miniature connectors. Bob . . . ________________________________________________________________________________
From: "Steve Sampson" <SSampson.SLN21(at)london.edu>
Subject: re: ov protection for internal v.r. alternators
Date: Feb 01, 2004
Clay - is anyone looking into this for you? It sounds like plenty of people are getting blown alternators after putting the B&C stuff on. Steve. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Clay R Subject: AeroElectric-List: re: ov protection for internal v.r. alternators Now I see the following warning on Vans web site on the alternator page. (I think this was added this week) Warning! The internally regulated 60 ampere alternator should not be used with overvoltage protection systems. If you open the charging circuit while it is in operation, it will destroy the regulator. -Clay __________________________________ --- Incoming mail is certified Virus Free. --- ________________________________________________________________________________
From: "Gary Casey" <glcasey(at)adelphia.net>
Subject: RE: Strain relief
Date: Feb 01, 2004
<> That's exactly what I do, and I do that for the typical "Molex" connector as well, since they don't have a particularly robust built-in strain relief. Gary Casey ________________________________________________________________________________
Date: Feb 01, 2004
From: Clay R <clayr_55(at)yahoo.com>
Subject: RE: re: ov protection for internal v.r. alternators
The cost to buy a 35A externally regulated alternator, regulator, and bracket from another supplier was just a little more than the cost to repair my Vans 60A alternator ($70). So, that's what I did. I still completely agree that there must be a way to disconnect an internally regulated alternator from the electrical system, and agree with Bob's advice there. However, I don't like the fact that any trip of the OV protection or the alt field switch will fry the alternator. (or at least Vans alternator) This is what it took to push me from the internally regulated alternator that I already had, to an externally regulated unit. I'm glad I found out about this on the ground instead of at a later date. The lesson learned is that I think this information should be added to the wiring diagram for OV protection so others will know about this limitation too. (Vans has already added it to their web page, and hopefully will add it to the instructions that come with the alternator) Right now, I'm planning on leaving the contactor in place, even with the new externally regulated alternator unless this isn't a good idea. (the only possible downside I can think of is that the contactor could fail and it really isn't necessary.) I WILL test it though, to make sure the alternator stops producing power when I turn off the Alt field switch. All in all, this experience is just one more way we all learn exactly how things electrical work in our airplanes. I can tell you that after dealing with this issue I REALLY know how the alternator and charging system works, when I didn't before. I just hope that sharing my experience leads to more knowledge for others and safer planes for all to follow. Still looking forward to Bob's take on this too. (I could still be wrong) --Clay Sampson" Clay - is anyone looking into this for you? It sounds like plenty of people are getting blown alternators after putting the B&C stuff on. Steve. __________________________________ ________________________________________________________________________________
Date: Feb 01, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: RE: OV protection for internally regulated alternators
As promised, I've been looking into this problem and I've crafted a white paper on the topic. Here is the text of the paper . . . ------------------------------------------- "Load Dump" Damage to Alternators with Built-in Regulators Bob Nuckolls 1 February 2004 >AeroElectric-List message posted by: "Ned Thomas" <315(at)cox.net> > >For what it is worth, I had an internally regulated alternator >on my RV6A. I had an overvoltage occur and had no way to >shut it off except land and turn off the engine. When >I smelled the battery acid cooking out I was quite concerned. >I was able to land before ruining the battery but even tho >I immediately turned off the master when I found the >voltmeter reading high, I did find that one of my strobes >had fried. After this happened I installed the OV protection >recommended by Bob. In the event you do encounter an OV >situation you must be able to isolate the alternator. >I was lucky, the battery could have blown up... >----- Original Message ----- >From: "Clay R" <clayr_55(at)yahoo.com> >Now I see the following warning on Vans web site on >the alternator page. (I think this was added this week) >Warning! >The internally regulated 60 ampere alternator should not >be used with overvoltage protection systems. If you >open the charging circuit while it is in operation, >it will destroy the regulator. >AeroElectric-List message posted by: "Steve Sampson" Clay - is anyone looking into this for you? It sounds >like plenty of people are getting blown alternators >after putting the B&C stuff on. BACKGROUND (1) The "B&C stuff" is only a collection of parts described in documents described in the AeroElectric Connection. Let us take care as to how the phenomenon is described with respect to implied cause and effect. It's not B&C's architecture but AeroElectric Connection architecture . . . B&C only sells the parts to implement it. (2) For years and since day-one of my participation in B&C's development and marketing of alternators, we have preached the doctrine of externally regulated alternators. Examples of this philosophy are found throughout early writings and particularly in chapters on alternators and regulators in the 'Connection. A simple inspection of B&C's offerings from the beginning will show that only externally regulated alternators are offered. (3) There has been a lot of interest in adapting internally regulated alternators to aircraft because they are so readily available and cheap. Further, they've produced an excellent track record of reliability on cars . . . it seems a shame not exploit that characteristic in aircraft. (4) The challenge for adapting internally regulated alternators to airplanes has always been making them behave like externally regulated alternators and generators before them. On the instrument panel there is a switch labeled ALT OFF/ON. One expects that operation of this switch will produce the same result whether you're sitting in a 1965 C-172 or a 2004 RV-8. (5) Most alternators with built in regulators, once given the ON command via the rear-connected control wire will indeed come alive . . . but since this wire was originally intended only as a means for the EFI controller on a car to delay onset of engine loads after starting, there was no requirement for being able to turn the alternator OFF via this same wire. So, the vast majority of automotive take-offs cannot be turned OFF by removing +14v from the control wire via panel mounted switch. This condition was experienced by Mr. Thomas in the anecdote cited earlier. (6) While the probability of regulator failure in cars is exceedingly low, it is not zero. We've heard anecdotal stories of unhappy, high-dollar events taking place in airplanes after failure of an internally regulated alternator. (7) With the goal of addressing a desire in the marketplace to utilize off-the-car technology, figure Z-24 was developed to address both controllability and overvoltage issues with the lowest practical parts count and without modifying the alternator. RECENT HISTORY It seems that there have been a rash of failures of internally regulated alternators installed per Figure Z-24. Let's review the inner workings and shortcomings of the modern, internally regulated alternators. We know that all alternators run best with a battery connected across their output. The battery is an excellent filter for the noise inherent on DC power generated by rectified 3-phase AC power. The battery also provides a flywheel effect . . . a kind of electrical inertia that damps out the frisky nature of an alternator's ability to quicky respond to and control its own output. A phenomenon labeled by the automotive industry as "load dump" speaks to a characteristic native to the physics of alternator performance. Its existence has been known since the beginnings of alternator use in vehicles . . . but it was only a concern after a proliferation of solid state electronics for fuel injection systems, ignition systems, anti-lock brakes, etc. Should an alternator producing a lot of power be suddenly disconnected from the load, it may generate what would be properly called a surge of voltage exceeding bus voltage by several times. If the load dump is limited to shedding of normal system loads, the battery's electrical inertia will be in place to smooth over the event. However, if the disconnection includes the battery, no mitigating electrical-mass is present to capture a significant energy transient. In aviation parlance, a "load dump" is rapid shedding of normal system loads. The scenario we are discussing might be more appropriately called a "battery dump". Unlike relatively low energy spikes characteristic of switching transients on inductive loads, a battery dump event is longer and carries a lot more energy. In the spring of 1998, there was a romance in the OBAM aircraft community with products called transient voltage suppressors (TVS). A school of thought suggested that the electrical system be sprinkled with these little critters to ward off effects of any gremlins of the overvoltage persuasion which may be lurking about the system. The suggested technique was to install a TVS on the power feeder for each vulnerable accessory. There was an extensive discussion thread. You may review published excerpts of that discussion at: http://aeroelectric.com/articles/spike.pdf This was before we began to consider and refine any notions of using internally regulated alternators in OBAM aircraft. In that thread, I suggested it was much better to (1) identify and mitigate such hazards at their source and/or (2) design accessories to be immune to such hazards. For decades, DO-160 has been an effective guideline for development of robust victims while MIL-STD-704 outlined design goals for output quality of power generation equipment. Here are but a few of hundreds of relevant documents on the phenomenon to be found on the web . . . http://www.sto-p.com/pfp/pfp-transients.htm http://www.onsemi.com/pub/Collateral/CS3341-D.PDF http://www.audifans.com/archives/1998/08/msg00929.html . . . do a Google search on "load dump" and "alternator" for a wealth of useful expansion of the topic. WHAT'S HAPPENING? The original discussions 4 years ago focused on the need to protect system accessories from the effects of alternator behavior. In the cases before us now, the victim is NOT airframe system accessories being hammered by a skittish alternator. These are cases where the alternator is killing itself . . . or more accurately, killing its own voltage regulator. If you look over the specifications for modern, solid state regulator chips, you'll find references to protection against load dump conditions built right onto the chip. I believe what we're observing now is a shortcoming of relatively mature automotive take-off alternators with regulators that do not enjoy this kind of protection. Referring to the group of block diagrams in this document, note that I've illustrated 4 configurations of installation architecture for alternators with built in regulators. (download http://www.aeroelectric.com/articles/Alternator_Failures.pdf to get the illustration) (1) The first diagram is captioned "AUTOMOTIVE" and it illustrates the relationship between battery and alternator in virtually all automotive applications. The battery is ALWAYS connected to the alternator. System loads are controlled via panel switches and/or ignition switch but portions of the power distribution system are always hot, even when the vehicle is parked. Not desirable on airplanes. (2) The second configuration is "FIGURE Z-24" referring to an architecture described in the AeroElectric Connection to accommodate two hard-and-fast design goals for using an alternator in an airplane: (a) absolute control of the alternator operation from the cockpit irrespective of flight condition and (b) protection against the very rare but potentially hazardous and expensive overvoltage condition. (3) The third configuration describes an ill-conceived recommendation suggesting deletion of the alternator disconnect and wiring the alternator to the airplane a-la-automotive. Note that while this configuration prevents the pilot from switching an alternator off while in operation, it does not prevent the battery from being taken off line. If we disconnect the alternator from the system while leaving the battery on as allowed with Figure Z-24, only the alternator is at-risk for self destruction. When you leave the alternator connected to the system and shut off the battery master, there is still risk of a battery-dump transient. While system loads will soak up some transient energy and mitigate amplitude and duration of the event, now the whole system is subjected to the transient. In airplanes like the Baron and Bonanza where alternators and battery master switches are separate, non-interlocked controls, switches can be manipulated in a manner that will produce the same "battery dump" effect that we're discussing. So the potential for this effect is not new nor is it unique to the nifty little alternators so popular in the OBAM aircraft community. (4) The fourth configuration illustrates an experiment to be conducted which may prove the usefulness of a technique intended to tame the dragon. A PROPOSED GAME PLAN (1) If you have Figure Z-24 installed and you're already flying or nearly ready to fly, don't change anything. Although you may never need the protections Z-24 offers, I don't recommend you go flying without it. It is EASY to prevent battery dump damage to the alternator by controlling sequence of operation for the switches. [a] Battery master is the first switch to come on before cranking the engine and it should stay on until after engine shutdown. [b] The alternator control switch may be turned on before cranking the engine but it's probably better to leave it off until after the engine is running. [c] At the end of the flight, shut the engine down before first turning off the alternator . . . . [d] . . . followed by turning of the battery master switch. Following suggestions in any of the Z-figures in the 'Connection will provide you with interlocked battery master and alternator control switches wired so as to prevent an alternator from remaining on-line with the battery disconnected. The battery dump transient is generated by the disconnection of the battery from the alternator b-lead terminal while the alternator is working hard. It can't be working hard if the engine is not running. The warning published by Van's is accurate as far as it goes but misses important points with respect to absolute operational control of the alternator from the cockpit and overvoltage protection. So, if you don't diddle with the switch while the engine is running, your alternator is not at risk for battery dump damage and you retain both operational control and overvoltage protection. (2) If you have yet to select an alternator but need to do it soon, you cannot go wrong with installing an alternator designed for aircraft service. Alternators using external regulation are easily managed for both operational control and overvoltage protection by simply opening the field lead. This activity does not generate the battery dump transient we're discussing. (3) I'm planning to test an alternator with built in regulation on a test stand using a fat TVS device connected as shown in the last block diagram. I'll be making measurements of worst-case transient energies and making sure that the diode we select is adequately sized to the task. NOTE If anyone out there remembers the zener diode that Pelican Aviation used to stick on the back side of their alternators (some STC'd no less!) while calling it "overvoltage protection" please recall that this was neither ov protection nor was it a practical solution to the problem before us now. After the bench testing studies are complete, I'll be looking for volunteers who are already flying Figure Z-24 alternator control schemes. I will supply a pair of TVS diodes for installation on your airplane. You will be asked to conduct a series of battery dump simulations. After the simulations, you'll be asked to install the second diode and return the first one to me for inspection. Once we've done the repeatable experiment to demonstrate suitability of the "fix", this paper will be updated to publish the results and Figure Z-24 will be updated appropriately. In the mean time, I'll supply a copy of this paper to Van's in with the hope that it will clarify the issues and forestall some poorly founded modifications to electrical systems in the OBAM aircraft community. Please feel free to circulate this document for both its informative value and potential for critical review. As a closing note to this document, I ran across this paper: http://www.st.com/stonline/books/pdf/docs/4345.pdf . . . written by the folks at SGS-Thompson on battery dump mitigation. This paper describes a proposed technique for building battery dump management right into the alternator . . . what a concept! Whether or not this capability will be offered in automotive products suited to airplanes soon is hard to predict. In the meantime, it's a no-brainer to make the alternators we have work quite nicely. The bottom line folks . . . I believe there is good value in the use of internally regulated alternators on airplanes. However, it's important that we make decisions based upon good science that helps us understand and accommodate their unique characteristics. Bob . . . ________________________________________________________________________________
Date: Feb 01, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: OV protection for alternators with built in regulators
I'm told that a warning notice has been published on Van's website concerning damage to alternators having built in regulators that are wired per Figure Z-24 in the AeroElectric Connection. I've researched the problem and crafted a white paper outlining history and technical details of the phenomenon along with an interim work-around plus plans for development of a permanent fix. You're welcome to download the paper at http://www.aeroelectric.com/articles/Alternator_Failures.pdf Feel free to link to, or re-publish all or any part of this document as you see fit to service your customers. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Feb 02, 2004
From: Matt Jurotich <mjurotich(at)hst.nasa.gov>
Subject: SD-8 and meltdowns
Bob and All I have been watching for the story on the SD-8 and meltdown of the external regulator. Did I miss it or we don't have info yet? I thought Bob said he was going to do some experiments. Thanks Matthew M. Jurotich NASA/Goddard Space Flight Center Swales contractor to the JWST ISIM Systems Engineer m/c : 443 e-mail mail to: phone : 301-286-5919 fax : 301-286-1736 JWST URL: <http://ngst1.gsfc.nasa.gov ________________________________________________________________________________
From: "John Livingston" <livingjw(at)earthlink.net>
Subject: Re: RE: OV protection for internally regulated alternators
Date: Feb 02, 2004
Bob, If I have a progressive battery/alternator switch can I still get into trouble if I quickly slam it totally off instead of taking the alternator off line, pause then turn off the battery? I can see how this might happen during an incident, if, for instance, one smelled smoke in the cockpit. Is this one senerio of concern? John ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: AeroElectric-List: RE: OV protection for internally regulated alternators > > As promised, I've been looking into this problem and I've crafted > a white paper on the topic. Here is the text of the paper . . . > > ------------------------------------------- > "Load Dump" Damage to Alternators with Built-in Regulators > > Bob Nuckolls > 1 February 2004 > > >AeroElectric-List message posted by: "Ned Thomas" <315(at)cox.net> > > > >For what it is worth, I had an internally regulated alternator > >on my RV6A. I had an overvoltage occur and had no way to > >shut it off except land and turn off the engine. When > >I smelled the battery acid cooking out I was quite concerned. > >I was able to land before ruining the battery but even tho > >I immediately turned off the master when I found the > >voltmeter reading high, I did find that one of my strobes > >had fried. After this happened I installed the OV protection > >recommended by Bob. In the event you do encounter an OV > >situation you must be able to isolate the alternator. > >I was lucky, the battery could have blown up... > > >----- Original Message ----- > >From: "Clay R" <clayr_55(at)yahoo.com> > > >Now I see the following warning on Vans web site on > >the alternator page. (I think this was added this week) > > >Warning! > > >The internally regulated 60 ampere alternator should not > >be used with overvoltage protection systems. If you > >open the charging circuit while it is in operation, > >it will destroy the regulator. > > >AeroElectric-List message posted by: "Steve Sampson" > > > Clay - is anyone looking into this for you? It sounds > >like plenty of people are getting blown alternators > >after putting the B&C stuff on. > > BACKGROUND > > (1) The "B&C stuff" is only a collection of parts described in documents > described in the AeroElectric Connection. Let us take care as to how the > phenomenon is described with respect to implied cause and effect. It's not > B&C's architecture but AeroElectric Connection architecture . . . B&C only > sells the parts to implement it. > > (2) For years and since day-one of my participation in B&C's development > and marketing of alternators, we have preached the doctrine of externally > regulated alternators. Examples of this philosophy are found throughout > early writings and particularly in chapters on alternators and regulators > in the 'Connection. A simple inspection of B&C's offerings from the > beginning will show that only externally regulated alternators are offered. > > (3) There has been a lot of interest in adapting internally regulated > alternators to aircraft because they are so readily available and cheap. > Further, they've produced an excellent track record of reliability on cars > . . . it seems a shame not exploit that characteristic in aircraft. > > (4) The challenge for adapting internally regulated alternators to > airplanes has always been making them behave like externally regulated > alternators and generators before them. On the instrument panel there is a > switch labeled ALT OFF/ON. One expects that operation of this switch will > produce the same result whether you're sitting in a 1965 C-172 or a 2004 RV-8. > > (5) Most alternators with built in regulators, once given the ON command > via the rear-connected control wire will indeed come alive . . . but since > this wire was originally intended only as a means for the EFI controller on > a car to delay onset of engine loads after starting, there was no > requirement for being able to turn the alternator OFF via this same wire. > So, the vast majority of automotive take-offs cannot be turned OFF by > removing +14v from the control wire via panel mounted switch. This > condition was experienced by Mr. Thomas in the anecdote cited earlier. > > (6) While the probability of regulator failure in cars is exceedingly low, > it is not zero. We've heard anecdotal stories of unhappy, high-dollar > events taking place in airplanes after failure of an internally regulated > alternator. > > (7) With the goal of addressing a desire in the marketplace to utilize > off-the-car technology, figure Z-24 was developed to address both > controllability and overvoltage issues with the lowest practical parts > count and without modifying the alternator. > > RECENT HISTORY > > It seems that there have been a rash of failures of internally regulated > alternators installed per Figure Z-24. Let's review the inner workings and > shortcomings of the modern, internally regulated alternators. We know that > all alternators run best with a battery connected across their output. The > battery is an excellent filter for the noise inherent on DC power generated > by rectified 3-phase AC power. The battery also provides a flywheel effect > . . . a kind of electrical inertia that damps out the frisky nature of an > alternator's ability to quicky respond to and control its own output. > > A phenomenon labeled by the automotive industry as "load dump" speaks to a > characteristic native to the physics of alternator performance. Its > existence has been known since the beginnings of alternator use in > vehicles . . . but it was only a concern after a proliferation of solid > state electronics for fuel injection systems, ignition systems, anti-lock > brakes, etc. Should an alternator producing a lot of power be suddenly > disconnected from the load, it may generate what would be properly called a > surge of voltage exceeding bus voltage by several times. If the load dump > is limited to shedding of normal system loads, the battery's electrical > inertia will be in place to smooth over the event. However, if the > disconnection includes the battery, no mitigating electrical-mass is > present to capture a significant energy transient. In aviation parlance, > a "load dump" is rapid shedding of normal system loads. The scenario we are > discussing might be more appropriately called a "battery dump". > > Unlike relatively low energy spikes characteristic of switching transients > on inductive loads, a battery dump event is longer and carries a lot more > energy. In the spring of 1998, there was a romance in the OBAM aircraft > community with products called transient voltage suppressors (TVS). A > school of thought suggested that the electrical system be sprinkled with > these little critters to ward off effects of any gremlins of the > overvoltage persuasion which may be lurking about the system. The suggested > technique was to install a TVS on the power feeder for each vulnerable > accessory. > > There was an extensive discussion thread. You may review published excerpts > of that discussion at: > > http://aeroelectric.com/articles/spike.pdf > > This was before we began to consider and refine any notions of using > internally regulated alternators in OBAM aircraft. > > In that thread, I suggested it was much better to (1) identify and mitigate > such hazards at their source and/or (2) design accessories to be immune to > such hazards. For decades, DO-160 has been an effective guideline for > development of robust victims while MIL-STD-704 outlined design goals for > output quality of power generation equipment. > > Here are but a few of hundreds of relevant documents on the phenomenon to > be found on the web . . . > > http://www.sto-p.com/pfp/pfp-transients.htm > > http://www.onsemi.com/pub/Collateral/CS3341-D.PDF > > http://www.audifans.com/archives/1998/08/msg00929.html > > . . . do a Google search on "load dump" and "alternator" for a wealth of > useful expansion of the topic. > > WHAT'S HAPPENING? > > The original discussions 4 years ago focused on the need to protect system > accessories from the effects of alternator behavior. In the cases before us > now, the victim is NOT airframe system accessories being hammered by a > skittish alternator. These are cases where the alternator is killing itself > . . . or more accurately, killing its own voltage regulator. > > If you look over the specifications for modern, solid state regulator > chips, you'll find references to protection against load dump conditions > built right onto the chip. I believe what we're observing now is a > shortcoming of relatively mature automotive take-off alternators with > regulators that do not enjoy this kind of protection. > > Referring to the group of block diagrams in this document, note that I've > illustrated 4 configurations of installation architecture for alternators > with built in regulators. > > (download > > http://www.aeroelectric.com/articles/Alternator_Failures.pdf > > to get the illustration) > > (1) The first diagram is captioned "AUTOMOTIVE" and it illustrates the > relationship between battery and alternator in virtually all automotive > applications. The battery is ALWAYS connected to the alternator. System > loads are controlled via panel switches and/or ignition switch but portions > of the power distribution system are always hot, even when the vehicle is > parked. Not desirable on airplanes. > > (2) The second configuration is "FIGURE Z-24" referring to an architecture > described in the AeroElectric Connection to accommodate two hard-and-fast > design goals for using an alternator in an airplane: (a) absolute control > of the alternator operation from the cockpit irrespective of flight > condition and (b) protection against the very rare but potentially > hazardous and expensive overvoltage condition. > > (3) The third configuration describes an ill-conceived recommendation > suggesting deletion of the alternator disconnect and wiring the alternator > to the airplane a-la-automotive. Note that while this configuration > prevents the pilot from switching an alternator off while in operation, it > does not prevent the battery from being taken off line. If we > disconnect the alternator from the system while leaving the battery on as > allowed with Figure Z-24, only the alternator is at-risk for self destruction. > > When you leave the alternator connected to the system and shut off the > battery master, there is still risk of a battery-dump transient. While > system loads will soak up some transient energy and mitigate amplitude and > duration of the event, now the whole system is subjected to the transient. > > In airplanes like the Baron and Bonanza where alternators and battery > master switches are separate, non-interlocked controls, switches can be > manipulated in a manner that will produce the same "battery dump" effect > that we're discussing. So the potential for this effect is not new nor is > it unique to the nifty little alternators so popular in the OBAM aircraft > community. > > (4) The fourth configuration illustrates an experiment to be conducted > which may prove the usefulness of a technique intended to tame the dragon. > > A PROPOSED GAME PLAN > > (1) If you have Figure Z-24 installed and you're already flying or nearly > ready to fly, don't change anything. Although you may never need the > protections Z-24 offers, I don't recommend you go flying without it. It is > EASY to prevent battery dump damage to the alternator by controlling > sequence of operation for the switches. > > [a] Battery master is the first switch to come on before cranking the > engine and it should stay on until after engine shutdown. > > [b] The alternator control switch may be turned on before cranking the > engine but it's probably better to leave it off until after the engine is > running. > > [c] At the end of the flight, shut the engine down before first turning > off the alternator . . . . > > [d] . . . followed by turning of the battery master switch. > > Following suggestions in any of the Z-figures in the 'Connection will > provide you with interlocked battery master and alternator control switches > wired so as to prevent an alternator from remaining on-line with the > battery disconnected. > > The battery dump transient is generated by the disconnection of the battery > from the alternator b-lead terminal while the alternator is working hard. > It can't be working hard if the engine is not running. The warning > published by Van's is accurate as far as it goes but misses important > points with respect to absolute operational control of the alternator from > the cockpit and overvoltage protection. So, if you don't diddle with the > switch while the engine is running, your alternator is not at risk for > battery dump damage and you retain both operational control and overvoltage > protection. > > (2) If you have yet to select an alternator but need to do it soon, you > cannot go wrong with installing an alternator designed for aircraft > service. Alternators using external regulation are easily managed for both > operational control and overvoltage protection by simply opening the field > lead. This activity does not generate the battery dump transient we're > discussing. > > (3) I'm planning to test an alternator with built in regulation on a test > stand using a fat TVS device connected as shown in the last block diagram. > I'll be making measurements of worst-case transient energies and making > sure that the diode we select is adequately sized to the task. > > NOTE > > If anyone out there remembers the zener diode > that Pelican Aviation used to stick on the back > side of their alternators (some STC'd no less!) > while calling it "overvoltage protection" please > recall that this was neither ov protection nor > was it a practical solution to the problem > before us now. > > After the bench testing studies are complete, I'll be looking for > volunteers who are already flying Figure Z-24 alternator control schemes. I > will supply a pair of TVS diodes for installation on your airplane. You > will be asked to conduct a series of battery dump simulations. After the > simulations, you'll be asked to install the second diode and return the > first one to me for inspection. > > Once we've done the repeatable experiment to demonstrate suitability of the > "fix", this paper will be updated to publish the results and Figure Z-24 > will be updated appropriately. In the mean time, I'll supply a copy of this > paper to Van's in with the hope that it will clarify the issues and > forestall some poorly founded modifications to electrical systems in the > OBAM aircraft community. Please feel free to circulate this document for > both its informative value and potential for critical review. > > As a closing note to this document, I ran across this paper: > > http://www.st.com/stonline/books/pdf/docs/4345.pdf > > . . . written by the folks at SGS-Thompson on battery dump mitigation. This > paper describes a proposed technique for building battery dump management > right into the alternator . . . what a concept! Whether or not this > capability will be offered in automotive products suited to airplanes soon > is hard to predict. In the meantime, it's a no-brainer to make the > alternators we have work quite nicely. > > The bottom line folks . . . I believe there is good value in the use of > internally regulated alternators on airplanes. However, it's important that > we make decisions based upon good science that helps us understand and > accommodate their unique characteristics. > > Bob . . . > > ________________________________________________________________________________
From: "Dan Checkoway" <dan(at)rvproject.com>
Subject: trick for combing out shield?
Date: Feb 02, 2004
Is there any slick trick for combing out braided shielding more easily? Case in point, RG-400 with its double layer of shielding. )_( Dan RV-7 N714D http://www.rvproject.com ________________________________________________________________________________
Subject: My Jabiru J400 made test flights,
Date: Feb 03, 2004
From: "Scott, Ian" <ian_scott(at)commander.com>
Last Sunday the my Jabiru J400 did its first test flight and a subsequent flight of a few hours, all was good, and all the smoke stayed in the wires. Elevated CHT due to the new engine, all the rest good and nearly 2000Fpm climb, man this is a rocket. Ian ________________________________________________________________________________
From: "David Carter" <dcarter(at)datarecall.net>
Subject: Fw: RV-List: RE: Dynon EMI (different scenario)
Date: Feb 02, 2004
This interesting thread on the RV-list probaly has a place on the Aeroelectric list, also, in case some players aren't monitoring both. David ----- Original Message ----- From: "Kevin Behrent" <kbehrent(at)cascadiasoftware.com> Subject: Re: RV-List: RE: Dynon EMI (different scenario) > --> RV-List message posted by: Kevin Behrent > > "Paul Boyce, Ph.D." wrote: > > > --> RV-List message posted by: "Paul Boyce, Ph.D." <matronicspost@csg-i.com> > > > > There's a couple of very disappointing things about this situation: > > > > 1) in a total electric failure emergency, my backup handheld radio will most > > likely be rendered useless. > > > > 2) in an otherwise excellent product, those engineering folks at Dynon have > > completely dropped the ball in not doing thorough Quality Control checks on > > EMI. Isn't it obvious that in a highly electrified environment such as an > > airplane cockpit, one MUST check for EMI? Is that too much to ask? > > > > I will be giving them a call tomorrow. > > > > Paul > > > > One possible reason why some people are having "noticeable" EMI interference > and others don't is the quaility and vintage of radio(s) that they have > installed. > > I say this because I have experienced this when I had a complete panel upgrade > on my Mooney where a complete Garmin stack was put in, but I retained my old, > trusty, Narco Mark 12D+/DME. The GNS430 and the Narco constantly interfered with > each other and both units were sent back to the respective factory on multiple > occassions. What was finally determined, by both manufactures, was noise > filtering capability on both units. The 430 does a pretty good in pre/post > filtering so that the large LCD panel would not interfere with "newer" avionics. > The Narco, on the other hand, has little pre filtering, thus is very reactive to > the lcd screen. It also emits it's own share of emi that the 430 tries to > handle, but fails when conditions are right. The solution, however exceptable > but not perfect, was shielding everything, and doing some rework on the radio > trays to help shield. > > The lesson I learned was not to mix new new with old. For what it cost to > minimize the problem, I could have purchased a second 430. > > We had the President of Dynon speak at our January EAA monthly meeting and I can > say that he and his engineers are very bright people and they will find a way to > reduce or eliminate the problem. On the other hand, LCD screens will always > emit a certain level of radiation that older generation of radios do not > filter. As glass panels evolve, so does radio filtering. However, don't expect > that your radio(s) are properly filtered to guard againt these emissions. > > It would be interesting to study the type of avionics being used by both groups > and see if there are any similarities. > > > Kevin Behrent > RV-9A - Wings > EAA 326, President > > ________________________________________________________________________________
Date: Feb 02, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: DIY audio amp
>Bob: > >I am building your stereo audio mixer and had questions: > >http://www.aeroelectric.com/Catalog/AEC/9009/9009-700D.pdf > >The schematic shows resistor R101, 102, 108 but there are no places for >them on the etched circuit board. Where do I put them? > >Where do the input resistors R104, 105, 106, 107 go? Do they go across the >header jumpers? Sorry to take so long to get back with you on this. Seems revision D of the assembly document was missing a parts locator figure. I've repaired the omission and published revision E at: http://www.aeroelectric.com/Catalog/AEC/9009/9009-700E.pdf You are correct, those parts are on the header. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Feb 02, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: SD-8 and meltdowns
> > >Bob and All > >I have been watching for the story on the SD-8 and meltdown of the external >regulator. Did I miss it or we don't have info yet? I thought Bob said he >was going to do some experiments. I've got the regulator in-hand . . . too many irons in the fire to do the study this week. I'm getting ready for the KC seminar next weekend. Perhaps next week. Bob . . . ________________________________________________________________________________
From: KITFOXZ(at)aol.com
Date: Feb 03, 2004
Subject: Re: trick for combing out shield?
In a message dated 2/2/2004 10:22:24 PM Eastern Standard Time, dan(at)rvproject.com writes: Is there any slick trick for combing out braided shielding more easily? Case in point, RG-400 with its double layer of shielding. )_( Dan RV-7 N714D http://www.rvproject.com Dan, I have always used a scribe for the task. It is best to not get too greedy, but comb out a short section at a time, working back towards the root. A large needle is a good substitute for the scribe. With all strands parallel, the connector will have the best, uniform bite. John P. Marzluf Columbus, Ohio Kitfox Outback (out back in the garage) ________________________________________________________________________________
Date: Feb 03, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: trick for combing out shield?
> >In a message dated 2/2/2004 10:22:24 PM Eastern Standard Time, >dan(at)rvproject.com writes: >Is there any slick trick for combing out braided shielding more easily? >Case in point, RG-400 with its double layer of shielding. Why comb it out? If you want to make connections to double shields like RG-400 coax, it's probably better to trim the shields just as if you were going to install a crimp on connector. Then wrap the exposed shield with a piece of braid and solder it. This is a modification of the technique shown in: http://www.aeroelectric.com/articles/pigtail/pigtail.html For wires with single shields, try the technique shown here: http://www.aeroelectric.com/articles/shldwire/shldwire.html This might even work with double shielded wire like RG-400, I've not tried it. In any case, I think you'll be more pleased with the outcome if you don't un-braid the strands. Doing that tends to produce a finished termination that looks like it's having a bad hair day. Bob ________________________________________________________________________________
From: DWENSING(at)aol.com
Date: Feb 03, 2004
Subject: Re: trick for combing out shield?
In a message dated 2/2/04 10:22:24 PM Eastern Standard Time, dan(at)rvproject.com writes: > Is there any slick trick for combing out braided shielding more easily? > Case in point, RG-400 with its double layer of shielding. > I use a crochet hook. It has a small very smooth hook that works great and does not damage the shield wires if done gently. You can purchase at your local fabric store. Dale Ensing ________________________________________________________________________________
Date: Feb 03, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Dynon EMI (different scenario)
Hmmm, funny this should pop up right now in the OBAM aircraft community . . . Just yesterday, I was invited to work a project involving players I won't name but suffice it to say that there are some aspects of the current crop of flat panel displays that are needing closer examination. In some cases, the antagonist flight instrument does meed DO-160 emissions requirements but the frequencies of interest are so stable and coherent as to offer some problems (albeit small ones) to radio receivers on the airplane. Other aspects of radiation discovered exceed DO-160 requirements and are broad band noises that degrade performance of other systems. Be advised that this problem is not unique to the low-dollar players. If I learn something of this situation that can be shared in terms of the simple-ideas, I'll share it with the List. With respect to the anecdotes cited below: The builder might get acceptable if not completely quiet performance from the hand-held by connecting it to an external antenna remote as practical from the cockpit. It's true that older radios were NOT explored for their vulnerabilities to broad band noises typical of microprocessor based electronics. If you have one of those battery powered short wave receivers, try exploring the environment around your desktop or laptop computer over the short wave frequencies. This is why computers have the sticker on them that states while they're qualified under FCC Part 15 rules for total emissions, they MIGHT still interfere with other radio based systems. In these cases, it is incumbent upon the operator of the antagonist to modify the situation to favor the victim. It's unfortunate that many developmental tasks are not fully understood until AFTER a product hits the marketplace. The designers and testers cannot anticipate EVERY installation variable. It's seldom reflects on the ability or integrity of the designers, only in the discovery of NEW questions not asked and answered before the product hit the field. Bob . . . ---------- Original Message ----------------------------- > > >This interesting thread on the RV-list probaly has a place on the >Aeroelectric list, also, in case some players aren't monitoring both. > >David > >----- Original Message ----- >From: "Kevin Behrent" <kbehrent(at)cascadiasoftware.com> >To: >Subject: Re: RV-List: RE: Dynon EMI (different scenario) > > > > --> RV-List message posted by: Kevin Behrent > > > > > "Paul Boyce, Ph.D." wrote: > > > > > --> RV-List message posted by: "Paul Boyce, Ph.D." ><matronicspost@csg-i.com> > > > > > > There's a couple of very disappointing things about this situation: > > > > > > 1) in a total electric failure emergency, my backup handheld radio will >most > > > likely be rendered useless. > > > > > > 2) in an otherwise excellent product, those engineering folks at Dynon >have > > > completely dropped the ball in not doing thorough Quality Control checks >on > > > EMI. Isn't it obvious that in a highly electrified environment such as >an > > > airplane cockpit, one MUST check for EMI? Is that too much to ask? > > > > > > I will be giving them a call tomorrow. > > > > > > Paul > > > > > > > One possible reason why some people are having "noticeable" EMI >interference > > and others don't is the quaility and vintage of radio(s) that they have > > installed. > > > > I say this because I have experienced this when I had a complete panel >upgrade > > on my Mooney where a complete Garmin stack was put in, but I retained my >old, > > trusty, Narco Mark 12D+/DME. The GNS430 and the Narco constantly >interfered with > > each other and both units were sent back to the respective factory on >multiple > > occassions. What was finally determined, by both manufactures, was noise > > filtering capability on both units. The 430 does a pretty good in pre/post > > filtering so that the large LCD panel would not interfere with "newer" >avionics. > > The Narco, on the other hand, has little pre filtering, thus is very >reactive to > > the lcd screen. It also emits it's own share of emi that the 430 tries to > > handle, but fails when conditions are right. The solution, however >exceptable > > but not perfect, was shielding everything, and doing some rework on the >radio > > trays to help shield. > > > > The lesson I learned was not to mix new new with old. For what it cost to > > minimize the problem, I could have purchased a second 430. > > > > We had the President of Dynon speak at our January EAA monthly meeting and >I can > > say that he and his engineers are very bright people and they will find a >way to > > reduce or eliminate the problem. On the other hand, LCD screens will >always > > emit a certain level of radiation that older generation of radios do not > > filter. As glass panels evolve, so does radio filtering. However, don't >expect > > that your radio(s) are properly filtered to guard againt these emissions. > > > > It would be interesting to study the type of avionics being used by both >groups > > and see if there are any similarities. ________________________________________________________________________________
From: "Dan Checkoway" <dan(at)rvproject.com>
Subject: Re: trick for combing out shield?
Date: Feb 03, 2004
Bob, I would have much preferred to do that. That's what I usually do on non-coax shielded wire. But a while back I read somewhere (this list, I believe) that you shouldn't use heat shrink on coax (i.e. RG-58) because the center conductor insulator could melt. I assumed that the heat generated by soldering would at least equal if not exceed that of a heat gun. Is soldering RG-400 really a kosher thing to do? I assume so, since you wouldn't have mentioned it, but I just want to confirm. Thanks, )_( Dan RV-7 N714D http://www.rvproject.com ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: trick for combing out shield? > > > > >In a message dated 2/2/2004 10:22:24 PM Eastern Standard Time, > >dan(at)rvproject.com writes: > >Is there any slick trick for combing out braided shielding more easily? > >Case in point, RG-400 with its double layer of shielding. > > Why comb it out? If you want to make connections to > double shields like RG-400 coax, it's probably better > to trim the shields just as if you were going to install > a crimp on connector. Then wrap the exposed shield with > a piece of braid and solder it. This is a modification > of the technique shown in: > > http://www.aeroelectric.com/articles/pigtail/pigtail.html > > For wires with single shields, try the technique shown here: > > http://www.aeroelectric.com/articles/shldwire/shldwire.html > > This might even work with double shielded wire like RG-400, > I've not tried it. > > In any case, I think you'll be more pleased with the outcome > if you don't un-braid the strands. Doing that tends to produce > a finished termination that looks like it's having a bad > hair day. > > Bob > > ________________________________________________________________________________
From: "Cy Galley" <cgalley(at)qcbc.org>
Subject: Re: trick for combing out shield?
Date: Feb 03, 2004
I tried soldering the shielding pigtail on a Cessna and it shorted out the pulses to ground even though my meter said it wasn't grounded. Became impossible to start. Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh Editor, EAA Safety Programs cgalley(at)qcbc.org or experimenter(at)eaa.org Always looking for articles for the Experimenter soon to be Sport Pilot ----- Original Message ----- From: "Dan Checkoway" <dan(at)rvproject.com> Subject: Re: AeroElectric-List: trick for combing out shield? > > Bob, > > I would have much preferred to do that. That's what I usually do on > non-coax shielded wire. But a while back I read somewhere (this list, I > believe) that you shouldn't use heat shrink on coax (i.e. RG-58) because the > center conductor insulator could melt. I assumed that the heat generated by > soldering would at least equal if not exceed that of a heat gun. > > Is soldering RG-400 really a kosher thing to do? I assume so, since you > wouldn't have mentioned it, but I just want to confirm. > > Thanks, > )_( Dan > RV-7 N714D > http://www.rvproject.com > > ----- Original Message ----- > From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> > To: > Subject: Re: AeroElectric-List: trick for combing out shield? > > > > > > > > > > >In a message dated 2/2/2004 10:22:24 PM Eastern Standard Time, > > >dan(at)rvproject.com writes: > > >Is there any slick trick for combing out braided shielding more easily? > > >Case in point, RG-400 with its double layer of shielding. > > > > Why comb it out? If you want to make connections to > > double shields like RG-400 coax, it's probably better > > to trim the shields just as if you were going to install > > a crimp on connector. Then wrap the exposed shield with > > a piece of braid and solder it. This is a modification > > of the technique shown in: > > > > http://www.aeroelectric.com/articles/pigtail/pigtail.html > > > > For wires with single shields, try the technique shown here: > > > > http://www.aeroelectric.com/articles/shldwire/shldwire.html > > > > This might even work with double shielded wire like RG-400, > > I've not tried it. > > > > In any case, I think you'll be more pleased with the outcome > > if you don't un-braid the strands. Doing that tends to produce > > a finished termination that looks like it's having a bad > > hair day. > > > > Bob > > > > > > ________________________________________________________________________________
From: Joel Harding <cajole76(at)ispwest.com>
Subject: shunt switch
Date: Feb 03, 2004
I'm looking for a recommendation for a high quality mini switch ( one fourth inch throat size) to select between the shunt in my alternator line and one in the battery lead, before it enters the volt amp meter. Joel Harding GRT EFIS on the way ________________________________________________________________________________
Date: Feb 03, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: trick for combing out shield?
> >Bob, > >I would have much preferred to do that. That's what I usually do on >non-coax shielded wire. But a while back I read somewhere (this list, I >believe) that you shouldn't use heat shrink on coax (i.e. RG-58) because the >center conductor insulator could melt. I assumed that the heat generated by >soldering would at least equal if not exceed that of a heat gun. > >Is soldering RG-400 really a kosher thing to do? I assume so, since you >wouldn't have mentioned it, but I just want to confirm. Sure . . . we don't want to solder to RG-58 because it's made of peanut-butter and bubble-gum . . . typical of materials around in 1945 when that stuff was designed. RG-400 is quite solder friendly. I used heat-gun installed solder sleeves on it all the time. Bob . . . ________________________________________________________________________________
Date: Feb 03, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> regulated alternators
Subject: Re: RE: OV protection for internally
regulated alternators regulated alternators > > >Bob, > > If I have a progressive battery/alternator switch can I still get into >trouble if I quickly slam it totally off instead of taking the alternator >off line, pause then turn off the battery? I can see how this might happen >during an incident, if, for instance, one smelled smoke in the cockpit. Is >this one senerio of concern? No, do this with the engine off. Where folks are getting into trouble is with unnecessary operation of the alternator switch while the engine is running. There are lots of controls on an airplane that are operated during narrowly restricted stages of flight. You don't lower flaps at 175 kts, You don't pull the mixture to cutoff at cruise, you don't select OFF on the fuel selector while in flight, etc. etc. In all my years of flying, I've never had a situation where I've felt a need to turn either a battery or alternator switch off after the engine is running except to shut the airplane down at the end of a flight. The problem with alternator vulnerability manifests itself only because folks operated switches in a manner inconsistent with a trouble free flight. If someone writes to say, "I lowered my flaps a cruise and they broke off the airplane", nobody would be surprised at the result, only wonderment at why anyone believed it was a useful thing to do. Same thing with a potentially vulnerable, self-regulated alternator. If you do smell smoke in the cockpit, then concern for the alternator's regulator is a secondary issue. That's why absolute control over the alternator's connection to the system is offered with the Z-24 configuration. Operate the system just like you've operated in C-172 for the last 40+ years and vulnerability to battery-dump damage is never going to be a problem. Bob . . . ________________________________________________________________________________
Date: Feb 03, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: My Jabiru J400 made test flights,
> > >Last Sunday the my Jabiru J400 did its first test flight and a subsequent >flight of a few hours, all was good, and all the smoke stayed in the wires. >Elevated CHT due to the new engine, all the rest good and nearly 2000Fpm >climb, man this is a rocket. Chalk up another one for the OBAM aircraft industry . . . the only segment of GA that is growing both in numbers and technological stature. Hat's off to brother Ian! Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Feb 03, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Kapton?
>Hello Bob, > >Thanks for your prompt reply. To first answer your question. Yes, I was >going to use it on our Model 5 Safari Kitfox that is about 70% complete. I >too think that it is Kapton wire, but I am not sure. I do not have a spec. >sheet on it either. > >I am nearly four years retired from Sikorsky Aircraft and I suspect that is >where I obtained the wire. I did a quick check on the internet against this >wire and the only thing that comes up is a chafing issue on a Sikorsky >Blackhawk. I have about 1400 feet of 20awg. If it's Kapton, I don't think I'd use it in your airplane. I was advised AGAINST Kapton 20 years ago when I was working the Gates-Piaggio project at Lear . . . seems the Navy was already having heartburn with that stuff on carrier based airplanes. Why it has persisted for all these years in commercial ships is beyond my understanding. I will invite you to join us on the AeroElectric List to continue this and similar discussions. It's useful to share the information with as many folks as possible. A further benefit can be realized with membership on the list. There are lots of technically capable folks on the list who can offer suggestions too. You can join at . . . http://www.matronics.com/subscribe/ Thanks! Bob . . . -------------------------------------------- ( Knowing about a thing is different than ) ( understanding it. One can know a lot ) ( and still understand nothing. ) ( C.F. Kettering ) -------------------------------------------- ________________________________________________________________________________
Date: Feb 03, 2004
From: Clay R <clayr_55(at)yahoo.com>
Subject: Re: RE: OV protection for internally regulated alternators
How many people out there were taught in the C-172 that you could switch the alternator off and back on to test it during the runup? (watch the Ammeter jump back and forth) I was. I guess the question is "how long does it take" to burn up the internal regulator if the B-lead is disconnected? A second? 10 seconds? If accidently flipping a switch on my airplane is going to cause a component to instantly break, I'm going to put a big guard on it or change the design. --Clay (really sorry to keep flogging this horse) --- "Robert L. Nuckolls, III" , UNEXPECTED_DATA_AFTER_ADDRESS@.SYNTAX-ERROR. wrote: > Nuckolls, III" regulated > alternators > > > In all my years of flying, I've never had a > situation where > I've felt a need to turn either a battery or > alternator switch > off after the engine is running except to shut > the airplane down > at the end of a flight. (snip) > > Operate the system just like you've operated in > C-172 for > the last 40+ years and vulnerability to > battery-dump > damage is never going to be a problem. > > Bob . . . __________________________________ ________________________________________________________________________________
From: "Francis, David CMDR" <David.Francis(at)defence.gov.au>
Subject: SEC: UNCLASSIFIED - LIGHTED TOGGLE SWITCHES
Date: Feb 04, 2004
Folks, Knowing that B&C stock Carling switches, I asked if they would consider stocking some of the LT series lighted toggle switches. Below is the reply from B&C. Regards, David Francis, VH-ZEE, Canberra, Australia David, I can get the LT series switches on a special order. Now as far as stocking them, that will take me a few months, I have got other items that I am working on at this time, but I will keep the LT switches in consideration. Thanks, Todd Koerner B&C Specialty Products ________________________________________________________________________________
Date: Feb 03, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: OV protection for internally regulated alternators
> >How many people out there were taught in the C-172 >that you could switch the alternator off and back on >to test it during the runup? (watch the Ammeter jump >back and forth) > >I was. Why would you do this in an OBAM machine? If you have ACTIVE notification of low voltage (i.e. low voltage warning light) and the light goes out when the engine starts, what's all this flippy-flippy stuff about? Someone may have taught you to do that but if the ammeter was indicating anywhere to the right of zero, there was nothing more to be learned by operating the alternator switch. If you closed the master switch and the panel lights up, then that too is pretty good evidence that the battery contactor is working. I helped craft the 1960's versions of POH instructions for the SE Cessnas . . . don't know what they've put in there since I left but I'd be really surprised if this activity was a factory recommended pre-flight procedure. >I guess the question is "how long does it take" to >burn up the internal regulator if the B-lead is >disconnected? A second? 10 seconds? 10 MILLISECONDS . . . >If accidently flipping a switch on my airplane is >going to cause a component to instantly break, I'm >going to put a big guard on it or change the design. You've already changed the design by NOT owning a C-172. Your not prohibited from doing a lot of things differently that what you were taught by folks who understand less about your airplane than you do. If there's any possibility of operating a switch by accident, perhaps there's something that can be done with ergonomics of layout to eliminate it. If you have layouts similar to http://www.aeroelectric.com/temp/Switches.pdf Which switch would you be reaching for when you accidently got the DC PWR MASTER instead? Bob . . . ________________________________________________________________________________
Date: Feb 03, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: shunt switch
> > >I'm looking for a recommendation for a high quality mini switch ( one >fourth inch throat size) to select between the shunt in my alternator >line and one in the battery lead, before it enters the volt amp meter. Are you running cranking currents through the battery shunt? My personal choice of switches for ammeter shunts would be the C&K 7201SYZQE from Digikey and others. See: http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=212792&Row=201354&Site=US Bob . . . ________________________________________________________________________________
From: "Scott Hersha" <shersha(at)fuse.net>
Subject: Re: shunt switch
Date: Feb 03, 2004
Bob, I don't if there is an ammeter shunt on my bus system or not, but there isn't any cranking amps going through the bus system..I have the EXP bus system. Maybe there is a ground problem with it. I tried a ferrite bead on my antenna leads today and they didn't help. Scott Hersha ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: shunt switch > > > > > > >I'm looking for a recommendation for a high quality mini switch ( one > >fourth inch throat size) to select between the shunt in my alternator > >line and one in the battery lead, before it enters the volt amp meter. > > Are you running cranking currents through the battery shunt? > > My personal choice of switches for ammeter shunts would be the > C&K 7201SYZQE from Digikey and others. See: > > http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=212792&Row=2013 54&Site=US > > Bob . . . > > ________________________________________________________________________________
From: "Scott Hersha" <shersha(at)fuse.net>
Subject: Noise
Date: Feb 03, 2004
I'm reading chapter 16 in the 'Connection' and will hopefullly find a problem to fix. I'm also on the list now. The ferrite torroid did not help. Still looking. Scott Hersha ________________________________________________________________________________
Date: Feb 03, 2004
From: Charlie Kuss <chaskuss(at)bellsouth.net>
Subject: Re: Quick connects
These look interesting. What sort of crimping tool is needed for these? Is it a proprietary tool? Or is the tool based on an existing standard? Charlie Kuss > >I bought a the Hirose mini circular connector from Digikey. They are very >small, easy to attach, locking, not real expensive, and sealed. I haven't >installed it yet but it looks perfect for the elevator trim to 5 wire Ray Allen >cable. > >There is a photo at the following site. > >http://www.hirose.com/ > >wires. This is for an electric trim tab servo and I would like to easily >remove for repair.> ________________________________________________________________________________
Date: Feb 03, 2004
From: Charlie Kuss <chaskuss(at)bellsouth.net>
Subject: Re: Lighted Toggle Switches
Dave, Give me more details on this. Are these panels some sort of fiber optic plastic, with a coating? It appears that the coating is removed by engraving. Do I assume correctly, that the text areas will emit light? This would be VERY nice. Charlie Kuss > >Another option if you guys are looking for the ultimate in "cool" is to >forget about lighted switches and go for a backlit switch panel, >professionally manufactured from your drawings by a company that does >flight simulator cockpits. Check out the stuff you can get at >www.AircraftSimulators.com > >I just had 2 switch panels made up that you can see at >http://www.myglasscockpit.com/SwitchPanelLeft.jpg >and >http://www.myglasscockpit.com/SwitchPanelCenter.jpg > >They can either supply the switches or supply the bare acrylic panel and >you provide your own switches. > >Dave Morris > > > >> >> >>Charlie, >> >>These look totally cool. I have not given this a lot of >>thought, but how would you used the colors in your airplane? >>I can see a lot of possibilities that could reduce workload >>and increase safety. >> >>Thanks, >>Mickey >> >> >> >http://www.carlingtech.com/pdf/s_lt.pdf >> > >> >Carling is the manufacturer of the switches sold by B&C Specialties. The >> LT series comes available with 5 different lighting colors and comes in a >> wide variety of switch styles. They have switches rated up to 15 amps as >> well. They are also available with 1/4" fast on terminals (as recommended by -- >> >>Mickey Coggins >>http://www.rv8.ch/ >>#82007 Wings >> >> > >Dave Morris > > ________________________________________________________________________________
Date: Feb 03, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Noise
> >I'm reading chapter 16 in the 'Connection' and will hopefullly find a >problem to fix. I'm also on the list now. The ferrite torroid did not >help. Still looking. >Scott Hersha What experiments have you conducted to deduce propagation mode for the noise? Bob . . . ________________________________________________________________________________
Date: Feb 03, 2004
From: Michel Therrien <mtherr(at)yahoo.com>
Subject: Re: RE: OV protection for internally regulated alternators
That battery dump damage thing... is this only related with the alternators from Vans, or any automotive alternators (including the Nippodensos found in japanese cars)? Is this a certainty that it will fail each time, or is it once in a lifetime that this will happen? Thanks! Michel --- "Robert L. Nuckolls, III" , > No, do this with the engine off. Where folks > are getting > into trouble is with unnecessary operation of > the alternator > switch while the engine is running. There are > lots of.... ===== ---------------------------- Michel Therrien CH601-HD, C-GZGQ http://mthobby.pcperfect.com/ch601 http://www.zenithair.com/bldrlist/profiles/mthobby http://pages.infinit.net/mthobby __________________________________ ________________________________________________________________________________
Date: Feb 03, 2004
From: Hi There <rv90619(at)yahoo.com>
Subject: Converting a Denso Alternator
I have a couple of Denso Alternators that I want to convert to nonregulated alternators. I've seen a few different sites that discribe how to do this, but not one that has the same type of regulator that are on my alternators. Both alternators I have have a plastic regulator/plug housing. There are cooling The regulator bolts to the diodes and brushes. I'm sure someone has done one of these alternators, I was at the junk yard today and many of the import cars used an alternator of this disign. I have some photos if that helps. Thanks for any help. Cameron --------------------------------- ________________________________________________________________________________
Date: Feb 04, 2004
From: "Richard E. Tasker" <retasker(at)optonline.net>
Subject: Re: Quick connects
Do you have a digikey part number for this? I tried looking on Digikey and couldn't find the one like the picture. Dick Tasker, RV9A #90573 N67BT(at)aol.com wrote: > >I bought a the Hirose mini circular connector from Digikey. They are very >small, easy to attach, locking, not real expensive, and sealed. I haven't >installed it yet but it looks perfect for the elevator trim to 5 wire Ray Allen >cable. > >There is a photo at the following site. > >http://www.hirose.com/ > >wires. This is for an electric trim tab servo and I would like to easily >remove for repair.> > > > > ________________________________________________________________________________
From: "Scott Hersha" <shersha(at)fuse.net>
Subject: Re: Noise
Date: Feb 04, 2004
I haven't tried any experiments yet except using a ferrite toroid on the antenna lead. No help. After reading chapter 16, I think I potentially have several areas for concern. My wires are probably not bundled properly to keep certain wires separated. My strobe power lead shield is grounded at the power supply only not the strobe lamp also. I'm going to build 3 capacitor/filters you describe, one for the intercom power, and one each for the two strobe power supplys. I'm also going to try connecting my com radio to a 'clean' power source..separate battery. I'll disconnect the radio antenna first to see if the noise is coming through it or the bus. All these 'experiments' will take some time, but if none of these work, I'll get back to you....Thanks, Scott Hersha ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: Noise > > > > >I'm reading chapter 16 in the 'Connection' and will hopefullly find a > >problem to fix. I'm also on the list now. The ferrite torroid did not > >help. Still looking. > >Scott Hersha > > What experiments have you conducted to deduce propagation > mode for the noise? > > Bob . . . > > ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: OV protection for internally regulated alternators
> >That battery dump damage thing... is this only related >with the alternators from Vans, or any automotive >alternators (including the Nippodensos found in >japanese cars)? > >Is this a certainty that it will fail each time, or is >it once in a lifetime that this will happen? > >Thanks! > >Michel Z-24 has been published for several years. I have to believe there have been a lot of systems installed and are flying. The questions are: (1) how many alternators are subject to this failure because their internal regulators are not rated for the battery-dump stress? (2) how many builders have put their particular alternator "to the test" by cycling the alternator control switch while the alternator was working hard? There are so many variables here that a truly quantitative response to your question cannot be deduced from what we know. I'm not sure which alternator Van's is selling. I THOUGHT it was an ND alternator. Does anyone know? It does take a combination of conditions to trigger the event: (1) relatively old design for built in regulator that is NOT protected from the battery-dump transient. (2) size of the transient is a function of how fast alternator is running and at what load when the connection between b-lead and battery is broken. When fitted with rudimentary electrical system instrumentation (low volts warning light or a voltmeter) there is no practical need or routinely exercised practice that calls for opening the alternator disconnect contactor while the engine is running IRRESPECTIVE of alternator vulnerability. If EVERY airplane I've ever rented over the past 23 years had been vulnerable to this failure mode, I'm 99.9% certain that the mode would not have been triggered while I was using the airplane . . . i.e. I've never had a situation arise where it was valuable or even interesting to operate the switch with the engine running. At the moment, my sense is that given the way MOST of us were taught (or not) on how to operate the airplane, the risks to even vulnerable alternators is quite low. The risk can be driven essentially zero once the magnitude of the transient is characterized and prophylactic measures implemented. At this point in the investigation, it would be a sad thing for a builder to jerk his perfectly working alternator off in knee-jerk response to truthful but poorly quantified warnings from well meaning folks who don't understand the system. Bob . . . ________________________________________________________________________________
Date: Feb 04, 2004
From: Mark Steitle <msteitle(at)mail.utexas.edu>
Subject: Re: Converting a Denso Alternator
> > >I have a couple of Denso Alternators that I want to convert to >nonregulated alternators. Cameron, I posted this procedure a while back, but couldn't find it in the archives. So, here is the procedure I used to convert my two ND alternators to external regulator mode. Mark ============================================= Bob N. strongly recommends using externally regulated alternators only, or modifying the internal regulator models so as to allow it to be shut down if necessary. (Supposedly, a voltage run-away can happen in a few seconds.) Problem is that the articles I read explaining how to convert the internally regulated alternators to external regulation didn't work. (Did I do something wrong?) I think I have worked out a simpler solution. The objective here is to isolate the field windings from the diode bridge so that the alternator can then be externally controlled. This is how I went about converting my alternators. First I removed the back cover, exposing the diode bridge, regulator assy. and brush holder. Then removed the regulator and brush holder and threw the regulator assy in the trash. Next I removed the brush holder and shaped a little brace from 1/8" phenolic that will support one side of the brush holder and isolate it from the diode bridge. This piece will be about 7/8" x 1/4" with a #8 hole in each end. Do not make this piece out of metal or it will short out the diode bridge. Also make up a jumper wire about three inches long with a ring terminal on each end. One end will attach to the right terminal on the brush holder and the other will attach to the alternator case (gnd.). The other terminal on the brush holder will need a spacer under it to keep everything aligned properly. The left brush will need to have the lead wire un-soldered from the brush holder. The wire comes through the back of the brush holder. Unsolder it there and drill out the hole just a bit to allow a #20 wire with shrink tube to fit snugly through the hole. Solder the #20 wire to the end of the braided wire on the brush. Now we're ready to reassemble the whole thing. Pass the #20 wire through the hole drilled in the brush holder and reinsert the spring and brush. Screw the brush holder back into place, with a spacer washer under the left terminal. The ground wire goes on the opposite terminal. Feed the wire soldered to the brush through a hole in the alternator cover, with a grommet to prevent chaffing. This wire will go to the "F" terminal of the external voltage regulator. I used a generic Ford unit from a mid-seventies model (approx. $10/ea from Auto Zone). The S & A terminals of the regulator tie together and get fed from the alt. switch & 5 amp breaker. The "B" terminal on the alternator goes to the battery contactor. The other terminal on the regulator isn't used. I modified two ND alternators using this method and they both work great. It takes about 30 minutes to do the modifications. All I need to do now is add a crowbar over-voltage protector to each regulator and I'm set to go. Or you can use a B&C voltage regulator with built-in OVP and low-voltage warning. ________________________________________________________________________________
From: Joel Harding <cajole76(at)ispwest.com>
Subject: Re: shunt switch
Date: Feb 04, 2004
On Feb 3, 2004, at 4:45 PM, Robert L. Nuckolls, III wrote: > > >> >> >> >> I'm looking for a recommendation for a high quality mini switch ( one >> fourth inch throat size) to select between the shunt in my alternator >> line and one in the battery lead, before it enters the volt amp meter. > > Are you running cranking currents through the battery shunt? > > No, it's in the lead from the battery to the ess. bus, so it won't be exposed to cranking currents. Joel ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Noise
> >I haven't tried any experiments yet except using a ferrite toroid on the >antenna lead. No help. After reading chapter 16, I think I potentially have >several areas for concern. My wires are probably not bundled properly to >keep certain wires separated. Possible problem but pretty low on list of probabilities > My strobe power lead shield is grounded at the >power supply only not the strobe lamp also. that's fine. ground shield at power supply end only. > I'm going to build 3 >capacitor/filters you describe, one for the intercom power, and one each for >the two strobe power supplys. Whups . . . don't do this yet. > I'm also going to try connecting my com radio >to a 'clean' power source..separate battery. Good idea. > I'll disconnect the radio >antenna first to see if the noise is coming through it or the bus. another good idea > All these >'experiments' will take some time, but if none of these work, I'll get back >to you. Do the detective work before you buy any parts. We await the results of your investigation. Bob . . . ________________________________________________________________________________
From: N27160(at)aol.com
Date: Feb 04, 2004
Subject: Antenna(S) for Com(s)?
Im adding a second com to my airplane. question is, do I need a second com antenna if I dont intend to transmit on both coms at the same time? ________________________________________________________________________________
Date: Feb 04, 2004
From: Rick Johnson <ricklj(at)silverstar.com>
Subject: start up/shut down procedure
Bob: I am wiring my RV7 according to your Z-13 and Z-24 diagrams. The only exception is I am using a 2-3 switch for my battery/alternator field switch instead of your 2-10. I would like to know what the proper start up - system check - shut down procedure should be. How should I check to see if the SD-8 alternator is working correctly after the engine is running? What will the ammeter on that circuit read if the auxiliary alternator switch is off? Sounds like after start up, I wouldn't want to switch off the battery/primary alternator then switch on the e-bus and auxiliary alternator to see if it is carrying the system load properly. I'm confused and would rather get some good advice from you before ruining some expensive equipment. And thanks for your fantastic web site and all the great advice you dispense here. rick ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Antenna(S) for Com(s)?
> >Im adding a second com to my airplane. question is, do I need a second com >antenna if I dont intend to transmit on both coms at the same time? Yes, you'll want to listen on both and while this could be done with a splitter, you can't used the splitter to transmit. If you use a relay or switch to put one antenna on the active transmitter, then you can't hear on both receivers. Further, putting such gizmos in the antenna for both transceivers gives you a single point of failure for both radios. You loose both utility and reliability when you try to share the antenna between two transceivers. Bob . . . ________________________________________________________________________________
From: "Wayne Berg" <wfberg(at)msn.com>
Subject: Re: Antenna(S) for Com(s)?
Date: Feb 04, 2004
Yes. You would need a coax switch in the line to isolate your transmitters. Without that or a second antenna you would be sending RF back into the second Com. Very bad and very expensive. Keep second com antenna at least 21" from the other com antenna. ----- Original Message ----- From: N27160(at)aol.com Subject: AeroElectric-List: Antenna(S) for Com(s)? Im adding a second com to my airplane. question is, do I need a second com antenna if I dont intend to transmit on both coms at the same time? ________________________________________________________________________________
Date: Feb 04, 2004
From: Clay R <clayr_55(at)yahoo.com>
Subject: Re: OV protection for internally regulated alternators
I'm going to reluctantly reply to your message and it will be my very last post to this list on the subject. I personally feel like I am being blamed for "not knowing" that I shouldn't have switched off the alternator switch while the engine was running. Sorry if I was taught it could be done on a Cessna... old habits die hard and turning off the alternator with the engine running shouldn't be OK on one plane but not another unless labeled as such. All I originally wanted was a warning on Z-24 to keep others from making the same mistake I did. --- "Robert L. Nuckolls, III" wrote: > Nuckolls, III" > > > Z-24 has been published for several years. I have > to believe there have been a lot of systems > installed > and are flying. The questions are: > Z-24 may have been published for several years... but that DOES NOT mean there are a lot of people flying it yet and there isn't a problem with it. The time required to build an airplane means that an idea needs to be out there for a year or two before it will be flying. When it was published, builders would need to be BEFORE the wiring stage to implement this idea easily... those that had already planned and started their wiring when z-24 was published probably didn't implement it because the idea was new and would require rework. I personally have never encountered another z-24 airplane flying, and neither had the DAR who certifies experimental planes every week in the Dallas area. Please, speak up if you have your flying plane wired like z-24 and have (or have not) seen any issues with it. Any additional data points will help. > (1) how many alternators are subject to this > failure > because their internal regulators are not rated > for > the battery-dump stress? > > (2) how many builders have put their particular > alternator "to the test" by cycling the > alternator > control switch while the alternator was working > hard? > I had my EFIS/One turned on (3.5A), the Lightspeed (1.3A), and the engine was at a slow idle. My battery was charged, and there were no radios on, no lights, nothing else... Does this qualify as working hard? > There are so many variables here that a truly > quantitative response to your question cannot be > deduced from what we know. > > I'm not sure which alternator Van's is selling. > I THOUGHT it was an ND alternator. Does anyone > know? My alternator from Vans has ND stamped on it. > > It does take a combination of conditions to > trigger the event: > > (1) relatively old design for built in regulator > that is NOT protected from the battery-dump > transient. > > (2) size of the transient is a function of how > fast alternator is running and at what load > when the connection between b-lead and battery > is broken. > > When fitted with rudimentary electrical system > instrumentation (low volts warning light or > a voltmeter) there is no practical need or > routinely exercised practice that calls for > opening the alternator disconnect contactor > while the engine is running IRRESPECTIVE > of alternator vulnerability. > > If EVERY airplane I've ever rented over the > past 23 years had been vulnerable to this > failure mode, I'm 99.9% certain that the mode > would not have been triggered while I was > using the airplane . . . i.e. I've never > had a situation arise where it was valuable > or even interesting to operate the switch > with the engine running. Rental airplanes and OBAM with z-24 are different... Rentals have externally regulated alternators without a contactor on the B-lead. > > At the moment, my sense is that given the way > MOST of us were taught (or not) on how > to operate the airplane, the risks to even > vulnerable alternators is quite low. > > The risk can be driven essentially zero once > the magnitude of the transient is characterized > and prophylactic measures implemented. At this > point in the investigation, it would be a sad > thing for a builder to jerk his perfectly working > alternator off in knee-jerk response to truthful > but poorly quantified warnings from well meaning > folks who don't understand the system. > > Bob . . . If I'm the one giving the truthful but poorly quantified warning, and don't understand the system, I'm sorry for being well-meaning and bringing it up. In retrospect, It would have been less stressful to quietly switch to an externally regulated alternator and left it for someone else to bring up. From the amount of email I've received, people seem to be happy I've shared my experience with the group. I do believe that once the problem is fully tested and understood a fix will be found for z-24 (or no problem will be found at all.. it was user error), and everyone will be happy once again. We live and learn and move on. For now Bob's right, don't change your alternator, just don't switch it off unless you want to help with the testing. ;-) -Clay __________________________________ ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Internally regulated alternators
>Here is a single point anecdotal observation. > >There is only one "Vans" 60 Amp alternator on our airfield, and it is a >rebuilt Mitsubishi. It looks like a later generation alternator ( Vented >frame, and internal fans); however it is of the ilk which, once activated >with the alt switch, it will not turn off with the alt switch. He has had >no serious problems with it. This one was purchased several years ago and >no telling what Van is selling now. This is consistent with other notes I'm getting. Van's has sold several different models over the years. None are new, most if not all are re-builds of some kind. Here's where it gets sticky. These modern alternators are mechanically and electrically quite robust. I'd guess that the most common reason for an alternator to be replaced is from brush wear, bearing wear or regulator failure. For every OEM that builds alternators as products they'll be proud of, there are dozens of after-market manufacturers of replacement regulators. I've often opined that ND alternators are among the best bets out there for a reliable alternator . . . this is reinforced with first hand knowledge of B&C's success with this product. B&C chooses not to put original equipment regulators to the test opting instead of offering their own flavor of external regulator. Once the alternator is opened for rebuilding, there is risk that the final product will become something less than the original manufacturer would be willing to put their brand on. The biggest single variable will be design of a replacement regulator. "Load dump" in cars is a very rare event . . . if a regulator manufacturer can make a few pennies more per unit by short changing load dump immunity . . . well, we know which way that decision often goes. >Most of the other Van's planes on our air field have Denso 40 A alternators >which came from Niagra Air Parts, and are new, fairly late models. These >look just like the B&C, but have internal regulators. I have personally >checked several times and it does shut down with the switch >(Sensor/regulator power?). I have it wired with the contactor and OVM. I >have also opened the Alt main (B lead) CB several times when under load and >it doesn't seem to harm it. I ain't doing that any more; however. I start >with it off and turn it on when the motor is running. It comes off after >engine shut down. A very rational approach to risk reduction . . . and it may be that you're seeing mostly new machines with ND original regulators that are not vulnerable to battery-dump events. >It is therefore my belief that the very popular 40 Amp Denso bought new from >Niagra has a regulator which has dump logic in it. It seems bullet proof in >that regard; however I still feel the need for the OV module and contactor, >in case of the internal failure mode which you describe. > >This is not much of a data point but it sounds like you are starting from >scratch, so I hope this helps. Very helpful, thanks! Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
From: N67BT(at)aol.com
Date: Feb 04, 2004
Subject: Connector for elevator trim servo
Photos and info on the Hirose connector I plan to use for the elevator trim servo are posted on my web site. http://users.aol.com/n67bt This thing looks like just the ticket. What do you think Bob N.? They cost around $14 for the pair. Bob Trumpfheller RV7A Western Colorado ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: start up/shut down procedure
> >Bob: I am wiring my RV7 according to your Z-13 and Z-24 diagrams. The >only exception is I am using a 2-3 switch for my battery/alternator field >switch instead of your 2-10. I would like to know what the proper start up >- system check - shut down procedure should be. How should I check to see >if the SD-8 alternator is working correctly after the engine is running? >What will the ammeter on that circuit read if the auxiliary alternator >switch is off? Sounds like after start up, I wouldn't want to switch off >the battery/primary alternator then switch on the e-bus and auxiliary >alternator to see if it is carrying the system load properly. I'm confused >and would rather get some good advice from you before ruining some >expensive equipment. And thanks for your fantastic web site and all the >great advice you dispense here. I'll suggest that you replace the 2-3 with a 2-10. Start with battery only. After engine starts, test the SD-8 before you turn the main alternator on. An option: Make the aux alternator switch a 2-3 where control current for main alternator goes through the second set of contacts such that the main alternator is disabled any time the SD-8 is ON. Start with the both DC PWR MASTER and AUX ALT switches ON. After preflight of the SD-8 is complete, turn it OFF and it will be replaced by the main alternator. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
From: "Ned Thomas" <315(at)cox.net>
Subject: Re: start up/shut down procedure
Date: Feb 04, 2004
Don't know if this is pertainant to this thread but I understand that once the SD-8 is energized it remains energized producing power until it stops rotating. It hasn't been made clear to me whether this is detrimental to have it running energized while disconnected from everything?? ________________________________________________________________________________
From: "Steve Sampson" <SSampson.SLN21(at)london.edu>
Subject: Re: OV protection for internally regulated alternators
/ ND alternator
Date: Feb 04, 2004
Michael/Bob, The alternator VANS shipped to me IS a refurb Nippon Denso (Spelling?) alternator. It is the one on p7 of the 2003 accesory catalogue. I had suggested the 35Amp externally regulated one but they suggested this was a better bet and lighter. Steve. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Robert L. Nuckolls, III Subject: AeroElectric-List: Re: OV protection for internally regulated alternators > >That battery dump damage thing... is this only related >with the alternators from Vans, or any automotive >alternators (including the Nippodensos found in >japanese cars)? > >Is this a certainty that it will fail each time, or is >it once in a lifetime that this will happen? > >Thanks! > >Michel Z-24 has been published for several years. I have to believe there have been a lot of systems installed and are flying. The questions are: (1) how many alternators are subject to this failure because their internal regulators are not rated for the battery-dump stress? (2) how many builders have put their particular alternator "to the test" by cycling the alternator control switch while the alternator was working hard? There are so many variables here that a truly quantitative response to your question cannot be deduced from what we know. I'm not sure which alternator Van's is selling. I THOUGHT it was an ND alternator. Does anyone know? It does take a combination of conditions to trigger the event: (1) relatively old design for built in regulator that is NOT protected from the battery-dump transient. (2) size of the transient is a function of how fast alternator is running and at what load when the connection between b-lead and battery is broken. When fitted with rudimentary electrical system instrumentation (low volts warning light or a voltmeter) there is no practical need or routinely exercised practice that calls for opening the alternator disconnect contactor while the engine is running IRRESPECTIVE of alternator vulnerability. If EVERY airplane I've ever rented over the past 23 years had been vulnerable to this failure mode, I'm 99.9% certain that the mode would not have been triggered while I was using the airplane . . . i.e. I've never had a situation arise where it was valuable or even interesting to operate the switch with the engine running. At the moment, my sense is that given the way MOST of us were taught (or not) on how to operate the airplane, the risks to even vulnerable alternators is quite low. The risk can be driven essentially zero once the magnitude of the transient is characterized and prophylactic measures implemented. At this point in the investigation, it would be a sad thing for a builder to jerk his perfectly working alternator off in knee-jerk response to truthful but poorly quantified warnings from well meaning folks who don't understand the system. Bob . . . --- Incoming mail is certified Virus Free. --- ________________________________________________________________________________
Date: Feb 04, 2004
From: Dave Morris <dave(at)davemorris.com>
Subject: Re: Antenna(S) for Com(s)?
You could build up a relay that your PTT connector plugs into, that would disconnect the 2nd comm radio from the antenna when you push the mike button. A lot has been written about that sort of thing in the amateur radio circles. If you're handy with a soldering iron, do a Google.com search for QSK TR SWITCH and see what's been written. Dave Morris N5UP > > > > > >Im adding a second com to my airplane. question is, do I need a second com > >antenna if I dont intend to transmit on both coms at the same time? > > Yes, you'll want to listen on both and while this could be done > with a splitter, you can't used the splitter to transmit. If you > use a relay or switch to put one antenna on the active transmitter, > then you can't hear on both receivers. > > Further, putting such gizmos in the antenna for both transceivers > gives you a single point of failure for both radios. You loose > both utility and reliability when you try to share the antenna > between two transceivers. > > Bob . . . > > Dave Morris ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: OV protection for internally regulated alternators
> >I'm going to reluctantly reply to your message and it >will be my very last post to this list on the subject. > >I personally feel like I am being blamed for "not >knowing" that I shouldn't have switched off the >alternator switch while the engine was running. Not at all my friend. There was nothing inherently wrong with turning the alternator on/off at ANY time . . . under the best of circumstances it shouldn't be a problem with ANY alternator on ANY airplane whether certified or OBAM. >Sorry if I was taught it could be done on a Cessna... >old habits die hard and turning off the alternator >with the engine running shouldn't be OK on one plane >but not another unless labeled as such. All I >originally wanted was a warning on Z-24 to keep others >from making the same mistake I did. Exactly. My comments were directed not at you for doing what you were taught but more toward your teachers who were augmenting the POH by suggesting a pre-flight activity that added no value . . . which serendipitously exposed a vulnerability of an alternator in an OBAM aircraft. This happens all the time in both the certified and OBAM world. Some day when I don't have to worry about ticking off the folks who sign my paychecks, I'll be able to relate some pretty hair-raising anecdotes in the heavily regulated and conformed world of certified aircraft. If my tone was skeptical/sarcastic/incredulous please know it had nothing to do with you personally. We're all products of our experiences. I'm singularly fortunate to have a rich history of experiences. My job is not to convince you of anything but to share what I've learned and try to explain how the simple-ideas piece together to make a system work/not-work. You're encouraged to use any part of this effort in which you find value. If you find something I've offered unconvincing, it's either because I'm in error or I've failed in my role as teacher. I am pleased that you DID reply and make me aware of your perceptions. It probably happens to others who feel like they're being chased off. I encourage you and others who participate on this list to remember that when the wild-eyed, gray beard in the Spam Can Capitol gets all excited, it's about the physics and logic of the matter, not the folks . . . and in particular folks who are helping me help others by sharing their own experiences. Please don't let this experience become inhibiting. There's a lot of sand and dust to sift to search out the simple-ideas. I value and appreciate your participation more than you know. When the dust finally settles on any discussion, it's my most sincere wish that we will have sorted out the best ideas worthy of passing on to others. Bob . . . ________________________________________________________________________________
From: "Steve Sampson" <SSampson.SLN21(at)london.edu>
Subject: Re: OV protection for internally regulated alternators
Date: Feb 04, 2004
Clay - thanks VERY much for raising this issue. It has been very helpful to me. Dont feel bad. Steve. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Clay R Subject: Re: AeroElectric-List: Re: OV protection for internally regulated alternators I'm going to reluctantly reply to your message and it will be my very last post to this list on the subject. I personally feel like I am being blamed for "not knowing" that I shouldn't have switched off the alternator switch while the engine was running. Sorry if I was taught it could be done on a Cessna... old habits die hard and turning off the alternator with the engine running shouldn't be OK on one plane but not another unless labeled as such. All I originally wanted was a warning on Z-24 to keep others from making the same mistake I did. --- "Robert L. Nuckolls, III" wrote: > Nuckolls, III" > > > Z-24 has been published for several years. I have > to believe there have been a lot of systems > installed > and are flying. The questions are: > Z-24 may have been published for several years... but that DOES NOT mean there are a lot of people flying it yet and there isn't a problem with it. The time required to build an airplane means that an idea needs to be out there for a year or two before it will be flying. When it was published, builders would need to be BEFORE the wiring stage to implement this idea easily... those that had already planned and started their wiring when z-24 was published probably didn't implement it because the idea was new and would require rework. I personally have never encountered another z-24 airplane flying, and neither had the DAR who certifies experimental planes every week in the Dallas area. Please, speak up if you have your flying plane wired like z-24 and have (or have not) seen any issues with it. Any additional data points will help. > (1) how many alternators are subject to this > failure > because their internal regulators are not rated > for > the battery-dump stress? > > (2) how many builders have put their particular > alternator "to the test" by cycling the > alternator > control switch while the alternator was working > hard? > I had my EFIS/One turned on (3.5A), the Lightspeed (1.3A), and the engine was at a slow idle. My battery was charged, and there were no radios on, no lights, nothing else... Does this qualify as working hard? > There are so many variables here that a truly > quantitative response to your question cannot be > deduced from what we know. > > I'm not sure which alternator Van's is selling. > I THOUGHT it was an ND alternator. Does anyone > know? My alternator from Vans has ND stamped on it. > > It does take a combination of conditions to > trigger the event: > > (1) relatively old design for built in regulator > that is NOT protected from the battery-dump > transient. > > (2) size of the transient is a function of how > fast alternator is running and at what load > when the connection between b-lead and battery > is broken. > > When fitted with rudimentary electrical system > instrumentation (low volts warning light or > a voltmeter) there is no practical need or > routinely exercised practice that calls for > opening the alternator disconnect contactor > while the engine is running IRRESPECTIVE > of alternator vulnerability. > > If EVERY airplane I've ever rented over the > past 23 years had been vulnerable to this > failure mode, I'm 99.9% certain that the mode > would not have been triggered while I was > using the airplane . . . i.e. I've never > had a situation arise where it was valuable > or even interesting to operate the switch > with the engine running. Rental airplanes and OBAM with z-24 are different... Rentals have externally regulated alternators without a contactor on the B-lead. > > At the moment, my sense is that given the way > MOST of us were taught (or not) on how > to operate the airplane, the risks to even > vulnerable alternators is quite low. > > The risk can be driven essentially zero once > the magnitude of the transient is characterized > and prophylactic measures implemented. At this > point in the investigation, it would be a sad > thing for a builder to jerk his perfectly working > alternator off in knee-jerk response to truthful > but poorly quantified warnings from well meaning > folks who don't understand the system. > > Bob . . . If I'm the one giving the truthful but poorly quantified warning, and don't understand the system, I'm sorry for being well-meaning and bringing it up. In retrospect, It would have been less stressful to quietly switch to an externally regulated alternator and left it for someone else to bring up. From the amount of email I've received, people seem to be happy I've shared my experience with the group. I do believe that once the problem is fully tested and understood a fix will be found for z-24 (or no problem will be found at all.. it was user error), and everyone will be happy once again. We live and learn and move on. For now Bob's right, don't change your alternator, just don't switch it off unless you want to help with the testing. ;-) -Clay __________________________________ --- Incoming mail is certified Virus Free. --- ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: start up/shut down procedure
> >Don't know if this is pertainant to this thread but I understand that once >the SD-8 is energized it remains energized producing power until it stops >rotating. > >It hasn't been made clear to me whether this is detrimental to have it >running energized while disconnected from everything?? No, the SD-8 is a permanent magnet alternator. It's ALWAYS producing output power whether or not it is turned on or loaded. At this time I'm unaware of any risk to the alternator system for operating it in the unloaded mode. There are airplanes flying the All-Electric-Airplane- on-a-Budget system with hundreds of trouble free hours on them. I had one builder write a year or more ago to tell me that the SD-8 in his airplane had been called upon to do its job after a wire became unhooked in his main alternator system. He said the system performed as expected. Bob . . . ________________________________________________________________________________
Date: Feb 04, 2004
Subject: Re: start up/shut down procedure
From: "Matt Prather" <mprather(at)spro.net>
Hi Bob, You said that the damaging voltage dump conditions happens when the alternator is under significant load, and is suddenly disconnected from that load. I gather that the problem is that some of the regulators don't pull down the field current fast enough to reduce the output of the alternator. Is that right? Or is that there is signficant inductive stored energy in the output of the alternator, and driving the output current to zero by disconnecting the alternator causese the output voltage to spike? Either way, would you say that the alternator can safely be disconnected when its output current is low (0A)? Have to wait until the battery is charged, and the pitot heat/nav lights are off... I also wonder how large the disconnect relay needs to be if attempting to disconnect the alternator from the bus causes such a large transient. Will the small relays that you sell be up to the task for an airplane that doesn't have a starter (ie, no large contactor)? One final question: What effect will the TVS have should the atl/reg suffer from an over voltage event, not related to turning off the alt switch while the engine is running? Will the TVS have a turn-on voltage higher than a typical overvoltage value? I suppose this may be a moot point, since if the regulator cooks, causing an ov even, I may not care what happens to the TVS, as long as the crow bar stuff works. None of these questions is of earth shattering significance, as it appears that you fully understand what is going on. However, I am interested in the topic out of curiousity. I am interested in seeing any data you take with regard to how long the battery/load dump even lasts, and how much total engergy is dissipated in the process. Regards, Matt Prather N34RD ________________________________________________________________________________
From: Kent Sorensen <kents(at)snak.com>
Subject: OBAM ?
Date: Feb 04, 2004
I keep seeing the acronym OBAM. It 's obviously referring to amateur built aircraft as opposed to certified ones. What does it stand for ? Owner Built Amateur Made or something ? Kent ________________________________________________________________________________
Date: Feb 04, 2004
From: Dj Merrill <deej(at)thayer.dartmouth.edu>
Subject: Re: OV protection for internally regulated
alternators Steve Sampson wrote: > > Clay - thanks VERY much for raising this issue. It has been very helpful to > me. Dont feel bad. Steve. And educational for me. It is good to question things less we become too complacent... ;-) Please continue to do so. Unless questioned, we generally take things our flight instructors teach us as gospel. Flight instructors are people, too, and might make mistakes or assumptions about things that aren't entirely true. This is a great forum for flushing out those myths about electrical related items in aircraft. I usually lurk, rather than post, and I've learned tons! :-) -Dj -- Dj Merrill Thayer School of Engineering ThUG Sr. Unix Systems Administrator 8000 Cummings Hall deej(at)thayer.dartmouth.edu - N1JOV Dartmouth College, Hanover, NH 03755 "On the side of the software box, in the 'System Requirements' section, it said 'Requires Windows 95 or better'. So I installed Linux." -Anonymous ________________________________________________________________________________
From: "Ned Thomas" <315(at)cox.net>
Subject: Alternator Recommendation and Conversions
Date: Feb 04, 2004
I thought I would recount my experience with Powermaster for those of you looking for an alternator. I would also suggest B&C. Powermaster is an automotive aftermarket firm specializing in racing products. You can buy them thru Summit and others and sometimes on eBay. http://store.summitracing.com/partdetail.asp?part=PWM%2D8162 After I experienced the OV on the RV6A, I took the alternator in to the local O'Reilly's and they put it on the test stand. It immediately produced 25 volts. I called the vendor, powermaster, and explained the situation. They said send it back and we'll repair it. They repaired it for free and ran it thru their tests and sent me their results tabulated and graphed. This alternator is a version of the Denso and was a "one wire" alternator. Powermaster told me they could configure it so that an additional wire would be available to turn on / off the alternator. So when I incorporated the Z-24 suggestions to the rewiring it worked fine. I had no problem with this alternator wired with the OV protection as suggested by Z-24. It was a 50 amp model 8162 and was very light at 5.68-lbs. It has what they call a "heat dispersant coating" that is black. http://www.powermastermotorsports.com/Racing/Denso_Alternators/denso_alternators.html More details: http://www.powermastermotorsports.com/Tech_Help/FAQ_s_-_Racing_Alternators/faq_s_-_racing_alternators.html#race3 For those interested the test data was: Max output power: 695 Watts Max output power under full load 53 Amps Field current 0.01 Amps Turn on Speed (less than): 2600RPM Leakage current tested @ 12 volts: 0.75 Amps Ripple current @ 2500 RPM: 11 Amps Pulley ratio: 2.05 There is a graph of Amps vs RPM and a Scope pattern at 2500 RPM that looks like a sine wavefrom +- about 7Amps I don't know what much of this means but it was nice to have the data...... Although the B&C weighs slightly more at 6.1 lbs it might be a better option. http://www.bandcspecialty.com/L40desc.html http://www.bandcspecialty.com/L40-out.PDF To convert and internally regulated alternator to and external regulated alternator I found the following link quite helpful: http://www.miramarcollege.net/programs/avim/faculty/north/alternator/index.htm Best Regards, Ned ________________________________________________________________________________
From: "Ageless Wings" <harley(at)AgelessWings.com>
Subject: OBAM ?
Date: Feb 04, 2004
Hi, Kent... I'll save Bob the effort this time! You are close....it's Owner Built and Maintained. Harley Long EZ N28EZ... in the hanger, getting sanded and primed! Harley Dixon Website: www.AgelessWings.com Email: harley(at)agelesswings.com Henrietta, NY USA |-----Original Message----- |From: owner-aeroelectric-list-server(at)matronics.com |[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Kent |Sorensen |Sent: Wednesday, February 04, 2004 4:24 PM |To: aeroelectric-list(at)matronics.com |Subject: AeroElectric-List: OBAM ? | | | |I keep seeing the acronym OBAM. It 's obviously referring to amateur |built aircraft as opposed to certified ones. What does it stand for ? | |Owner Built Amateur Made or something ? | |Kent | | | | | | | ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: OV protection for internally regulated alternators
> > >Michael/Bob, The alternator VANS shipped to me IS a refurb Nippon Denso >(Spelling?) alternator. It is the one on p7 of the 2003 accesory catalogue. >I had suggested the 35Amp externally regulated one but they suggested this >was a better bet and lighter. > >Steve. Thanks Steve. It may be that "refurb" regulators are the real root cause of the vulnerability. Bob . . . ________________________________________________________________________________
From: "Beckman, Rick" <Rick.Beckman(at)atk.com>
ernators
Subject: OV protection for internally regulated alt
ernators
Date: Feb 04, 2004
>I personally feel like I am being blamed ....... Please don't let this experience become inhibiting. There's a lot of sand and dust to sift to search out the simple-ideas. I value and appreciate your participation more than you know. When the dust finally settles on any discussion, it's my most sincere wish that we will have sorted out the best ideas worthy of passing on to others. Bob . . . Bob,.... Thanks for that excellent reply, further assuring your public that no matter what the discussion, it never becomes a personal grudge match with you and others involved. I, personally, have gleaned a wealth of information from all the Matronics sites to which I subscribe, definitely this one! Keep on keepin' on! See ya Saturday! God Bless! Rick ________________________________________________________________________________
From: "Dan Branstrom" <danbranstrom(at)verizon.net>
Subject: Re: OBAM ?
Date: Feb 04, 2004
Owner Built And Maintained. I asked the same question a while ago. ; ) Dan Branstrom ----- Original Message ----- From: "Kent Sorensen" <kents(at)snak.com> Subject: AeroElectric-List: OBAM ? > > I keep seeing the acronym OBAM. It 's obviously referring to amateur > built aircraft as opposed to certified ones. What does it stand for ? > > Owner Built Amateur Made or something ? > > Kent > > ________________________________________________________________________________
Date: Feb 04, 2004
From: Dave Morris <dave(at)davemorris.com>
Subject: Re: OBAM ?
> >I keep seeing the acronym OBAM. It 's obviously referring to amateur >built aircraft as opposed to certified ones. What does it stand for ? It's the sound made by an airplane builder when he discovers tab A does not fit in slot B. Dave Morris ________________________________________________________________________________
Date: Feb 04, 2004
From: Joe Dubner <jdubner(at)yahoo.com>
Subject: Re: OV protection for internally regulated alternators
On 04-Feb-04 11:48 Clay R wrote: > I personally feel like I am being blamed for "not > knowing" that I shouldn't have switched off the > alternator switch while the engine was running. [... deleted ..] > Please, speak up if you have your flying plane wired > like z-24 and have (or have not) seen any issues with > it. Any additional data points will help. Clay, if there's blame to be assigned (lets hope there isn't), I'll take some too. My Long-EZ is wired like Z-24 and I've turned off my alternator in flight many times and under vaying load conditions. My reasons may not pass muster but what the heck, it's my airplane. Some of these reasons are: 1) testing the operation of the alternator contactor I added; I was horrified to discover that my purchased Long-EZ had no way to disable the alternator in case of an electrical fire. 2) Troubleshooting a noisy Aerospace Logic EGT indicator; it worked OK on battery but noise from the alternator caused readings to vary. 3) Simulating alternator failure in flight; I wanted to see what it was like to fly battery only to my destination before it actually happened. No big deal. FWIW, my alternator has no identifying marks other than a "Hitachi" label. Perhaps I've just been lucky but I didn't know this was an issue either. Thank you for bringing this up and sharing your experience with the group. -- Joe Long-EZ 821RP Gilbert, AZ ________________________________________________________________________________
From: "AI Nut" <ainut(at)earthlink.net>
Subject: Re: start up/shut down procedure
Date: Feb 04, 2004
Web site? ----- Original Message ----- From: "Rick Johnson" <ricklj(at)silverstar.com> Subject: AeroElectric-List: start up/shut down procedure > > Bob: I am wiring my RV7 according to your Z-13 and Z-24 diagrams. The > only exception is I am using a 2-3 switch for my battery/alternator field > switch instead of your 2-10. I would like to know what the proper start up > - system check - shut down procedure should be. How should I check to see > if the SD-8 alternator is working correctly after the engine is running? > What will the ammeter on that circuit read if the auxiliary alternator > switch is off? Sounds like after start up, I wouldn't want to switch off > the battery/primary alternator then switch on the e-bus and auxiliary > alternator to see if it is carrying the system load properly. I'm confused > and would rather get some good advice from you before ruining some > expensive equipment. And thanks for your fantastic web site and all the > great advice you dispense here. > > rick > > ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: OV protection for internally regulated alternators
> >On 04-Feb-04 11:48 Clay R wrote: > > > I personally feel like I am being blamed for "not > > knowing" that I shouldn't have switched off the > > alternator switch while the engine was running. > >[... deleted ..] > > > Please, speak up if you have your flying plane wired > > like z-24 and have (or have not) seen any issues with > > it. Any additional data points will help. > >Clay, if there's blame to be assigned (lets hope there isn't), I'll take >some too. My Long-EZ is wired like Z-24 and I've turned off my >alternator in flight many times and under vaying load conditions. . . . if your alternator is a junk-yard take-off, it's quite likely to have the factory original voltage regulator in it. It's hard to tell without a teardown under experienced eyeballs. >My reasons may not pass muster but what the heck, it's my airplane. >Some of these reasons are: 1) testing the operation of the alternator >contactor I added; I was horrified to discover that my purchased Long-EZ >had no way to disable the alternator in case of an electrical fire. 2) >Troubleshooting a noisy Aerospace Logic EGT indicator; it worked OK on >battery but noise from the alternator caused readings to vary. 3) >Simulating alternator failure in flight; I wanted to see what it was >like to fly battery only to my destination before it actually happened. > No big deal. . . . and it shouldn't be. >FWIW, my alternator has no identifying marks other than a "Hitachi" >label. Perhaps I've just been lucky but I didn't know this was an issue >either. > >Thank you for bringing this up and sharing your experience with the group. Thanks for your input Joe. Bob . . . ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: OBAM ?
> > > > > >I keep seeing the acronym OBAM. It 's obviously referring to amateur > >built aircraft as opposed to certified ones. What does it stand for ? > >It's the sound made by an airplane builder when he discovers tab A does not >fit in slot B. Good one Dave! I'll have to remember that. I'm working on a white paper for the small aircraft directorate dealing with ageing aircraft issues. We'll start with alternators and batteries. I'm trying to drive home the point that aside from mechanical issues where things break loose and jam other things, neither of these items is by itself critical to flight. I've introduced the term OBAM to the FAA in this paper. Never can tell, it might germinate and take hold. The NEXT step is "CBOM" . . . commercially built, owner maintained. My dream machine is a Piper Pacer or Tri-Pacer with NICE front seats, a hell-of-a-cargo pad where the back seats used to be and a Z-13 electrical system. I think I could have a really nice mogas, x-country machine for well under $40K with a whole lot less build-time than starting from scratch. Bob . . . ________________________________________________________________________________
Date: Feb 04, 2004
From: Jim Oke <wjoke(at)shaw.ca> alternators / ND alternator
Subject: Re: OV protection for internally regulated
alternators / ND alternator ND alternator After following the Vans Nippon Denso saga for a day or so, I wonder if anyone can comment on the smaller Denso alternator that AeroSport Power supplies with their engines as an option. The one I received has a Nippon Denso tag as P/N 18504-6220 although it seems to be manufactured by Ishikawajima as P/N 100211-1680 and marketed by Denso. It has a B+ supply and can be run on a "single wire" control basis although there is a warning light connection as well. The unit has worked well in my limited flying to date (RV-6A). I am using a homebrew OVM with a B field contactor. And, no, I haven't experimented with a "battery dump" failure mode experiment as yet. Jim Oke RV-6A RV-3 Wpg, MB ----- Original Message ----- From: "Steve Sampson" <SSampson.SLN21(at)london.edu> Subject: RE: AeroElectric-List: Re: OV protection for internally regulated alternators / ND alternator > > Michael/Bob, The alternator VANS shipped to me IS a refurb Nippon Denso > (Spelling?) alternator. It is the one on p7 of the 2003 accesory catalogue. > I had suggested the 35Amp externally regulated one but they suggested this > was a better bet and lighter. > > Steve. > > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Robert > L. Nuckolls, III > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Re: OV protection for internally regulated > alternators > > > > > > > >That battery dump damage thing... is this only related > >with the alternators from Vans, or any automotive > >alternators (including the Nippodensos found in > >japanese cars)? > > > >Is this a certainty that it will fail each time, or is > >it once in a lifetime that this will happen? > > > >Thanks! > > > >Michel > > Z-24 has been published for several years. I have > to believe there have been a lot of systems installed > and are flying. The questions are: > > (1) how many alternators are subject to this failure > because their internal regulators are not rated for > the battery-dump stress? > > (2) how many builders have put their particular > alternator "to the test" by cycling the alternator > control switch while the alternator was working > hard? > > There are so many variables here that a truly > quantitative response to your question cannot be > deduced from what we know. > > I'm not sure which alternator Van's is selling. > I THOUGHT it was an ND alternator. Does anyone > know? > > It does take a combination of conditions to > trigger the event: > > (1) relatively old design for built in regulator > that is NOT protected from the battery-dump > transient. > > (2) size of the transient is a function of how > fast alternator is running and at what load > when the connection between b-lead and battery > is broken. > > When fitted with rudimentary electrical system > instrumentation (low volts warning light or > a voltmeter) there is no practical need or > routinely exercised practice that calls for > opening the alternator disconnect contactor > while the engine is running IRRESPECTIVE > of alternator vulnerability. > > If EVERY airplane I've ever rented over the > past 23 years had been vulnerable to this > failure mode, I'm 99.9% certain that the mode > would not have been triggered while I was > using the airplane . . . i.e. I've never > had a situation arise where it was valuable > or even interesting to operate the switch > with the engine running. > > At the moment, my sense is that given the way > MOST of us were taught (or not) on how > to operate the airplane, the risks to even > vulnerable alternators is quite low. > > The risk can be driven essentially zero once > the magnitude of the transient is characterized > and prophylactic measures implemented. At this > point in the investigation, it would be a sad > thing for a builder to jerk his perfectly working > alternator off in knee-jerk response to truthful > but poorly quantified warnings from well meaning > folks who don't understand the system. > > Bob . . . > > > --- > Incoming mail is certified Virus Free. > > --- > > ________________________________________________________________________________
From: "LarryRobertHelming" <lhelming(at)sigecom.net>
Subject: BNC bulkhead pass-through connectors
Date: Feb 04, 2004
In this reference, http://www.mpja.com/listitems.asp?dept=93&main=83 under the sub heading of GENDER CHANGER BNC CONNECTOR are two items that I do not understand and would like some help with what ISOLATED and NOT Isolated means with respect to BNC connectors. Larry ________________________________________________________________________________
Date: Feb 04, 2004
From: Dave Morris <dave(at)davemorris.com>
Subject: Re: BNC bulkhead pass-through connectors
I'm relatively sure it describes whether or not the outer conductor (where the shield connects) is isolated from the panel mounting hardware or not. Dave Morris At 06:16 PM 2/4/2004, you wrote: > > >In this reference, http://www.mpja.com/listitems.asp?dept=93&main=83 under >the sub heading of GENDER CHANGER BNC CONNECTOR are two items that I do not >understand and would like some help with what ISOLATED and NOT Isolated >means with respect to BNC connectors. > >Larry > > ________________________________________________________________________________
Date: Feb 04, 2004
From: Charlie Kuss <chaskuss(at)bellsouth.net>
Subject: Re: Converting a Denso Alternator #2
At 10:51 PM 2/3/2004, you wrote: > > >I have a couple of Denso Alternators that I want to convert to nonregulated alternators. I've seen a few different sites that discribe how to do this, but not one that has the same type of regulator that are on my alternators. Both alternators I have have a plastic regulator/plug housing. There are cooling The regulator bolts to the diodes and brushes. I'm sure someone has done one of these alternators, I was at the junk yard today and many of the import cars used an alternator of this disign. I have some photos if that helps. > > >Thanks for any help. > > >Cameron ________________________________________________________________________________
Date: Feb 04, 2004
From: Charlie Kuss <chaskuss(at)bellsouth.net>
Subject: Re: Converting a Denso Alternator #3
Cameron, As you will read in the article, the author shows how to convert both the Nippon Denso models and the Mitsubishi units as well. Charlie > > >I have a couple of Denso Alternators that I want to convert to nonregulated alternators. I've seen a few different sites that discribe how to do this, but not one that has the same type of regulator that are on my alternators. Both alternators I have have a plastic regulator/plug housing. There are cooling The regulator bolts to the diodes and brushes. I'm sure someone has done one of these alternators, I was at the junk yard today and many of the import cars used an alternator of this disign. I have some photos if that helps. > > >Thanks for any help. > > >Cameron ________________________________________________________________________________
Date: Feb 04, 2004
From: Charlie Kuss <chaskuss(at)bellsouth.net>
Subject: Re: Converting a Denso Alternator #3
Sorry folks, These last 2 posts were intended for Cameron off list. I've had a long hard day. I'm now "officially" brain dead! :-( Charlie Kuss > >Cameron, > As you will read in the article, the author shows how to convert both the Nippon Denso models and the Mitsubishi units as well. >Charlie > >> >> >>I have a couple of Denso Alternators that I want to convert to nonregulated alternators. I've seen a few different sites that discribe how to do this, but not one that has the same type of regulator that are on my alternators. Both alternators I have have a plastic regulator/plug housing. There are cooling The regulator bolts to the diodes and brushes. I'm sure someone has done one of these alternators, I was at the junk yard today and many of the import cars used an alternator of this disign. I have some photos if that helps. >> >> >>Thanks for any help. >> >> >>Cameron > > ________________________________________________________________________________
From: "Dan Checkoway" <dan(at)rvproject.com>
""
Subject: EMI solution for Dynon?
Date: Feb 04, 2004
http://www.4emi.com Has anybody seen or played with these? Sure seems like an incredibly elegant way to go -- IF it works! )_( Dan RV-7 N714D http://www.rvproject.com ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: start up/shut down procedure
> >Web site? http://www.aeroelectric.com Bob . . . ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: OV protection for internally regulated alternators
>alternators / ND alternator > >After following the Vans Nippon Denso saga for a day or so, I wonder if >anyone can comment on the smaller Denso alternator that AeroSport Power >supplies with their engines as an option. > >The one I received has a Nippon Denso tag as P/N 18504-6220 although it >seems to be manufactured by Ishikawajima as P/N 100211-1680 and marketed by >Denso. It has a B+ supply and can be run on a "single wire" control basis >although there is a warning light connection as well. > >The unit has worked well in my limited flying to date (RV-6A). I am using a >homebrew OVM with a B field contactor. > >And, no, I haven't experimented with a "battery dump" failure mode >experiment as yet. It's difficult to comment on any particular alternator until we're sure as to true root cause of the failures. The working hypothesis is that after-market regulators used by some re-build shops may not be as robust as the factory originals by ND and others. Probably the most revealing question to ask your alternator supplier . . . is this a new alternator or rebuilt? Not that rebuilt are automatically suspect . . . there are undoubtedly after-market regulators equal to OEM. Given that companies like ND sell MILLIONS of alternators per year, they can't afford a screwup that saves a few pennies per unit but opens doors to a ton of warranty claims. The after-market regulator folks are not so exposed. Their warranty covers only the regulator that costs them under $1 to build and they can always point to the fried chip and cry "load dump!". How many folks are going to know it's something the regulator SHOULD be able to tolerate? Don't do any "experimenting" until we have some data to work with. I've had conversation with two sets of folks about some testing. It won't happen until late next week at the earliest. Bob . . . ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Connector for elevator trim servo
> >Photos and info on the Hirose connector I plan to use for the elevator trim >servo are posted on my web site. > >http://users.aol.com/n67bt > >This thing looks like just the ticket. What do you think Bob N.? > >They cost around $14 for the pair. Hirose is a good house. I've used their stuff on several occasions when I needed lots of conductors in a small package. Bob . . . ________________________________________________________________________________
Date: Feb 04, 2004
From: "Richard E. Tasker" <retasker(at)optonline.net>
Subject: Re: BNC bulkhead pass-through connectors
That is correct. Isolated means that the whole assembly that the BNC connectors connect to is electrically isolated from the mounting flange. Non-isolated means that the mounting flange is connected to the part of the connector that connects to the shield of the coax. Dick Tasker, RV9A #90572 Dave Morris wrote: > >I'm relatively sure it describes whether or not the outer conductor (where >the shield connects) is isolated from the panel mounting hardware or not. > >Dave Morris > > >At 06:16 PM 2/4/2004, you wrote: > > > >> >> >>In this reference, http://www.mpja.com/listitems.asp?dept=93&main=83 under >>the sub heading of GENDER CHANGER BNC CONNECTOR are two items that I do not >>understand and would like some help with what ISOLATED and NOT Isolated >>means with respect to BNC connectors. >> >>Larry >> >> >> >> > > > > ________________________________________________________________________________
Date: Feb 04, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: EMI solution for Dynon?
> >http://www.4emi.com > >Has anybody seen or played with these? Sure seems like an incredibly >elegant way to go -- IF it works! They do work. I've had occasion to use them a couple of times in the past 20 years. Problem is that they're not cheap . . . and they use the same filtering technique on all pins whether the pin is a source/victim potential or not. For the most part, I've found it more economical to filter the pins that needed filtering with components appropriate to that pin's signal duties. Bob . . . ________________________________________________________________________________
Date: Feb 04, 2004
From: Dave Morris <dave(at)davemorris.com>
Subject: Re: EMI solution for Dynon?
I'll believe it when I see the spectrum analyzer output. EMI is a complex problem and I don't think those little things will do much good. Dave Morris At 09:39 PM 2/4/2004, you wrote: > >http://www.4emi.com > >Has anybody seen or played with these? Sure seems like an incredibly >elegant way to go -- IF it works! > >)_( Dan >RV-7 N714D >http://www.rvproject.com > > ________________________________________________________________________________
Date: Feb 04, 2004
From: Jerzy Krasinski <krasinski(at)direcway.com>
Subject: Re: Converting a Denso Alternator
I opened my internaly regulated Mitsubishi, and I found one irregular block containing the brush holders and regulator, all epoxy potted inside a fragile looking piece of plastic. I thought about milling out the regulator but it is very difficult to hold that thing in the mill, and it looked that I would have to make a new brush holder from scratch. I have spent a day looking at it and I gave up. I put the alternator back together and I will try to attach transorbs or a big varistor for protection. The problem is that information about the transients included in http://www.sto-p.com/pfp/pfp-transients.htm#load is showing voltage approaching 100V and internal resistance of the source between 0.1 and 1 ohm. That would imply that current through the varistor or transorb limiting output voltage to several volts could reach several hundreds amps. That does not seem to make any sense, I would expect that the alternator would try to make the output current equal to the current just before removal of the load, and such current would reduce the peak voltage down to the normal output voltage. I will connect the protective elements and we will see if it works. Anyway, my Mitsubishi is nearly impossible to convert in a simple way. But maybe somebody solved that problem? I would appreciate some info. Thank you, Jerzy Mark Steitle wrote: > > > >> >> >>I have a couple of Denso Alternators that I want to convert to >>nonregulated alternators. >> >> > >Cameron, >I posted this procedure a while back, but couldn't find it in the >archives. So, here is the procedure I used to convert my two ND >alternators to external regulator mode. > >Mark >============================================= >Bob N. strongly recommends using externally regulated alternators only, or >modifying the internal regulator models so as to allow it to be shut down >if necessary. (Supposedly, a voltage run-away can happen in a few seconds.) >Problem is that the articles I read explaining how to convert the >internally regulated alternators to external regulation didn't work. (Did I >do something wrong?) I think I have worked out a simpler solution. The >objective here is to isolate the field windings from the diode bridge so >that the alternator can then be externally controlled. > >This is how I went about converting my alternators. First I removed the >back cover, exposing the diode bridge, regulator assy. and brush holder. >Then removed the regulator and brush holder and threw the regulator assy in >the trash. Next ........................ > > ________________________________________________________________________________
Date: Feb 05, 2004
From: Charlie Kuss <chaskuss(at)bellsouth.net>
Subject: Re: Converting a Mitsu Alternator #2
The blurry photos are due to the fact that this article was faxed to me. Charlie > >I opened my internaly regulated Mitsubishi, and I found one irregular >block containing the brush holders and regulator, all epoxy potted >inside a fragile looking piece of plastic. I thought about milling out >the regulator but it is very difficult to hold that thing in the mill, >and it looked that I would have to make a new brush holder from >scratch. I have spent a day looking at it and I gave up. I put the >alternator back together and I will try to attach transorbs or a big >varistor for protection. The problem is that information about the >transients included in http://www.sto-p.com/pfp/pfp-transients.htm#load > is showing voltage approaching 100V and internal resistance of the >source between 0.1 and 1 ohm. That would imply that current through the >varistor or transorb limiting output voltage to several volts could >reach several hundreds amps. That does not seem to make any sense, I >would expect that the alternator would try to make the output current >equal to the current just before removal of the load, and such current >would reduce the peak voltage down to the normal output voltage. > > I will connect the protective elements and we will see if it works. > >Anyway, my Mitsubishi is nearly impossible to convert in a simple way. >But maybe somebody solved that problem? I would appreciate some info. >Thank you, >Jerzy ________________________________________________________________________________
Date: Feb 05, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Converting a Denso Alternator
> > >I opened my internaly regulated Mitsubishi, and I found one irregular >block containing the brush holders and regulator, all epoxy potted >inside a fragile looking piece of plastic. I thought about milling out >the regulator but it is very difficult to hold that thing in the mill, >and it looked that I would have to make a new brush holder from >scratch. I have spent a day looking at it and I gave up. I put the >alternator back together and I will try to attach transorbs or a big >varistor for protection. The problem is that information about the >transients included in http://www.sto-p.com/pfp/pfp-transients.htm#load > is showing voltage approaching 100V and internal resistance of the >source between 0.1 and 1 ohm. That would imply that current through the >varistor or transorb limiting output voltage to several volts could >reach several hundreds amps. That does not seem to make any sense, I >would expect that the alternator would try to make the output current >equal to the current just before removal of the load, and such current >would reduce the peak voltage down to the normal output voltage. Your thinking rationally now Jerry, gotta be careful around those who preach the gospel of doom-n-gloom. I think we know that an alternator is incapable of delivering more than its magnetics are designed for . . . even in a transient condition. So a battery-dump event would be limited to perhaps 10-20% more than the alternator's current rating. Also, I think the time constants cited are rather long and predicated on effects of system loads . . the effect we're intently interested in is an intentionally generated battery-dump when the disconnect contactor is opened and the alternator is totally unloaded. Like you, I've read all the literature designed to convince us that a happy world has transorbes sprinkled all over it, and gee, if little ones are good, fat ones are better. Let's keep stirring the pot with good science and repeatable experiments. This can be good stew yet. > I will connect the protective elements and we will see if it works. Are you planning an experiment with measurements? >Anyway, my Mitsubishi is nearly impossible to convert in a simple way. >But maybe somebody solved that problem? I would appreciate some info. That's not uncommon. The moldings that hold brushes and regulators tend to be integrated in ways that make it difficult to remove regulators and re-wire brushes. Bob . . . ________________________________________________________________________________
From: "Glen Matejcek" <aerobubba(at)earthlink.net>
Subject: ov protection for internal v.r. alternators
Date: Feb 05, 2004
Hi Bob and list- Something has occurred to me. While I've never been inside a ND alternator, and am certainly no guru of any sort, I have an idea I'd like your feedback on. It seems to me that the fundamental problem with regard to OV protection on these internally regulated alternators is the inability to cut the supply of power to the field during an OV event. How hard / appropriate would it be to open the regulator up, find the wire that feeds the field, cut it, bring the two resultant lines out of the case to a relay and a B&C OV module? When the system goes OV, power is removed from the field. It seems so simple, I feel like I'm missing something.... gm ________________________________________________________________________________
Date: Feb 05, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: 11133 Hersha
<5.0.0.25.2.20040204215217.015c1920(at)pop.central.cox.net> >I haven't tried the separate battery yet, that's my next experiment. The >radio noise does not go away if I disconnect the antenna - either radio, >either antenna. Squelsh is automatic and not controlable from the front of >the panel. I have 2 VAL COM 760's. Cheap radios, but I wanted 2 and I've >never had a problem with them in the past. . . . and I've never heard of them being a "problem" radio. I'm thinking there may be something basic the architecture of you system that's causing the problem. >My kit from Radio Shack (I'm building 3) came with a 220 micro farad >capacitor. Your plans diagram shows a 10 micro farad capacitor to be used. >Should I use the one supplied or go get the 10 micro farad? the kit should have come with the 10uf cap. If you have larger caps you want to use, that's fine too. Bob . . . ________________________________________________________________________________
Date: Feb 05, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: RG400
> >Sorry, but I've researched myself into a state of confusion and was hoping >you guys could help me out. > >I'm not to the point of installing avionics yet, but a buddy is finishing >up his RV-6 and is asking for help finishing up his avionics install. I've >got connectors and tools (fancy stripper and crimper) for RG-58 cable, but >he is using RG400. I've never worked with RG400 before. > >First, the connectors. I've seen some sites that indicate a single >connector for RG58 or RG400. Other sites specify a different connector for >the two. Is there really that big of a difference? It seems like there is >no reasonable way to tie to the second shield in the RG400 anyway with a >crimp connector. It depends on the tolerances of the specific connector. MOST connectors for RG400 will work with RG58 also. The connectors and tools offered by B&C work with both coaxes. >The other question on the stripper. It's one where you rotate a die for >RG6/RG58/RG59. It seems reasonable to me that the blades could be >adjusted, if necessary, with the RG58 position to get a good strip on the >RG400. Again it kind of depends on the second shield on the RG400. Yup, I've got a stripper that was supposedly set up for RG58 and it does a better job on 400. A little practice with a scrap of RG400 with an Xacto and #11 blade will do good too. Bottom line is don't make the first attempt at a new combination of tools and technologies the one that goes on your airplane. Get some extra connectors, pins, etc and see how well they work and what techniques you may need to refine to do the best job. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Feb 05, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: ov protection for internal v.r. alternators
> > >Hi Bob and list- > >Something has occurred to me. While I've never been inside a ND >alternator, and am certainly no guru of any sort, I have an idea I'd like >your feedback on. It seems to me that the fundamental problem with regard >to OV protection on these internally regulated alternators is the inability >to cut the supply of power to the field during an OV event. How hard / >appropriate would it be to open the regulator up, find the wire that feeds >the field, cut it, bring the two resultant lines out of the case to a relay >and a B&C OV module? When the system goes OV, power is removed from the >field. It seems so simple, I feel like I'm missing something.... Any modification to that end would be satisfactory . . . once you're inside, it's just about as easy to completely remove the built in regulator and bring out the field leads like the B&C mods. After that, you have MANY options for regulators and ov protection. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Feb 05, 2004
From: Jerzy Krasinski <krasinski(at)direcway.com>
Subject: Re: Converting a Denso Alternator
Jerzy Krasinski wrote: I will connect the protective elements and we will see if it works. Robert L. Nuckolls, III wrote: > Are you planning an experiment with measurements? > > > I just got a bunch of protective diodes and the biggest varistors I could get for a reasonable price. Unfortunately there is a 20X price jump for really big ones. However, it seems much more cost effective to put several smaller varistors in parallel. The choise between the diodes and varistors is difficult. Varistors are almost indestructible, but they have more gradual characteristics. That means they are likely to allow a bigger voltage increase in the conditions of a dump. Diodes have sharper current increase with voltage, but they are more fragile and they fail making a short, if they get too much energy. Such a short would not be nice. The solution is to put many of them in parallel - if I can isolate several similar diodes from the bunch I got.. In the mean time I keep reading whatever was written about the alternators. I do not have at home capabilities to check the protective devices in a pulsed way for high current. I will try to do that somewhere else. I will select more promising elements and attach them to the alternator hoping for the best. Jerzy ________________________________________________________________________________
From: "Scott Hersha" <shersha(at)fuse.net>
Subject: Re: 11133 Hersha <5.0.0.25.2.20040204215217.015c1920(at)pop.central.cox.net>
Date: Feb 05, 2004
Bob, I'm making 3 of the noise filters I got at Radio Shack, however they will not be as pretty as the one you made. When I snipped the choke leads shorter per plans I was left with two untinned copper wires. It was nearly impossibe to get solder to stick to the bare copper when soldering a tinned wire to it. I'm using a 30 watt iron and the kind of solder you recommended. The next two I made, I didn't cut the choke leads down so I could use the tinned ends. I had to wrap the choke wires over the top and glue the cap on the other side of the coil. I'll still run the wires through the coil gap and use a lot of glue to provide strain relief, but it will be a little less professional looking than yours. I just hope it works. Scott Hersha ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: AeroElectric-List: Re: 11133 Hersha <5.0.0.25.2.20040204215217.015c1920(at)pop.central.cox.net> > > >I haven't tried the separate battery yet, that's my next experiment. The > >radio noise does not go away if I disconnect the antenna - either radio, > >either antenna. Squelsh is automatic and not controlable from the front of > >the panel. I have 2 VAL COM 760's. Cheap radios, but I wanted 2 and I've > >never had a problem with them in the past. > > . . . and I've never heard of them being a "problem" radio. > I'm thinking there may be something basic the architecture > of you system that's causing the problem. > > >My kit from Radio Shack (I'm building 3) came with a 220 micro farad > >capacitor. Your plans diagram shows a 10 micro farad capacitor to be used. > >Should I use the one supplied or go get the 10 micro farad? > > the kit should have come with the 10uf cap. If you have larger > caps you want to use, that's fine too. > > Bob . . . > > ________________________________________________________________________________
From: "James E. Clark" <james(at)nextupventures.com>
Subject: OV Protection for Internally Regulated .. Another Question
Date: Feb 06, 2004
There has been a LOT of dialog along the lines mentioned below (opening up the alternator). I have looked but probably overlooked it so my question is: Is there a *summary* recommendation (or opinion) on what one could reasonably do to get additional protection WITHOUT opening the alternator???? The one is question is the 55 amp model from Van's. Thanks, James [snip] > > > >Something has occurred to me. While I've never been inside a ND > >alternator, and am certainly no guru of any sort, I have an idea I'd like > >your feedback on. It seems to me that the fundamental problem > with regard > >to OV protection on these internally regulated alternators is > the inability > >to cut the supply of power to the field during an OV event. How hard / > >appropriate would it be to open the regulator up, find the wire > that feeds > >the field, cut it, bring the two resultant lines out of the case > to a relay > >and a B&C OV module? When the system goes OV, power is removed from the > >field. It seems so simple, I feel like I'm missing something.... > > Any modification to that end would be satisfactory . . . once you're > inside, it's just about as easy to completely remove the built in > regulator and bring out the field leads like the B&C mods. > > After that, you have MANY options for regulators and ov protection. > > Bob . . . > > ________________________________________________________________________________
From: "hollandm" <hollandm(at)pacbell.net>
Subject: Shielded wire options
Date: Feb 05, 2004
In choosing shielded wire to hook up the radio jacks I've used some relatively inexpensive stuff that I found. Rather than the hightech stuff with braided shields this wire has a mylar foil, with a bleed wire. Is this an acceptable to use for audio hookups? I'm intend to use it to connect the Dynon external mag compass, which has been alleged to induce EMI problems. I don't want to cut corners when it makes a difference in safety, performance or reliability. Thanks ________________________________________________________________________________
Date: Feb 06, 2004
From: Jan de Jong <jan.de.jong(at)xs4all.nl>
Subject: Re: 11133 Hersha
"It was nearly impossibe to get solder to stick to the bare copper when soldering a tinned wire to it." You may have to scrape the "bare copper" to get to the bare copper... Jan de Jong ________________________________________________________________________________
Date: Feb 06, 2004
aeroelectric-list(at)matronics.com
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Flap breaker size
<5.0.0.25.2.20040106090414.01a21320(at)pop.central.cox.net> <5.0.0.25.2.20040107094407.01613008(at)pop.central.cox.net> <5.0.0.25.2.20040108104000.01b115f0(at)pop.central.cox.net> <5.0.0.25.2.20040114094816.01b2d630(at)pop.central.cox.net> <5.0.0.25.2.20040126085640.01a85e40(at)pop.central.cox.net> <5.0.0.25.2.20040126221300.01a651b8(at)pop.central.cox.net> >Hi Bob >I have that flap motor working now but think I may have a problem with the >circuit breaker. As you remember, I had the panel built and installed >"acres of breakers"...this was PB (pre-Bob). They used a 15 amp CB for the >flap circuit. Zenith showed a 5 amp breaker on their drawing. You used a >10 amp breaker on your drawing...I am using a 16 ga wire as you drew in your >schematic to the main bus. > >With this set-up, should I trade out the 15 amp breaker? > >Dale The Z-drawings are for describing architecture. The final selection for circuit protection has to be based on load analysis of the particular accessory being protected. If you have 16AWG run in, put a 10A breaker on it for now. Let's do some real measurements during your flyoff to see if the breaker is the right size. The recommendations by most kit suppliers for electrical issues are based on hearsay and seldom on calculations or measurements to refine the design. I will invite you to join us on the AeroElectric List to continue this and similar discussions. It's useful to share the information with as many folks as possible. A further benefit can be realized with membership on the list. There are lots of technically capable folks on the list who can offer suggestions too. Thanks! Bob . . . -------------------------------------------- ( Knowing about a thing is different than ) ( understanding it. One can know a lot ) ( and still understand nothing. ) ( C.F. Kettering ) -------------------------------------------- ________________________________________________________________________________
Date: Feb 06, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Shielded wire options
> >In choosing shielded wire to hook up the radio jacks I've used some >relatively inexpensive stuff that I found. Rather than the hightech stuff >with braided shields this wire has a mylar foil, with a bleed wire. Is >this an acceptable to use for audio hookups? I'm intend to use it to >connect the Dynon external mag compass, which has been alleged to induce >EMI problems. > >I don't want to cut corners when it makes a difference in safety, >performance or reliability. The "Beldfoil" shield is electrically superior to braided shield when it comes to electrical characteristics that define shielding effectiveness. It's just not available in tefzel insulated conductors. It will be fine for the application you proposed. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Feb 06, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> .. Another Question
Subject: Re: OV Protection for Internally Regulated
.. Another Question .. Another Question > > >There has been a LOT of dialog along the lines mentioned below (opening up >the alternator). I have looked but probably overlooked it so my question is: > >Is there a *summary* recommendation (or opinion) on what one could >reasonably do to get additional protection WITHOUT opening the >alternator???? > >The one is question is the 55 amp model from Van's. Yup, Figure Z-24 in the back of the AeroElectric Connection suggests a means for providing (1) absolute control of an internally regulated alternator and (2) providing ov protection. The question under consideration now is which, if any, alternators would do better with some means of filtering off the "load dump" phenomenon that seems to be responsible for damaging the regulators in some alternators. Risk of damage is VERY low if one observes simple operating protocols for panel switches that is consistent with the way these switches are operated 99.999% of the time anyhow. We may be able to drive the risk to essentially zero by (1) selecting alternators with regulators already immune to the load-dump phenomenon (as most OEM automotive products probably are) or (2) a judicious addition of devices to the alternator designed to address the physics of the phenomenon in a well considered manner. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Subject: Re: OV protection for internally regulated alternators
From: Jack Bloodgood <jackb(at)us.ibm.com>
Date: Feb 06, 2004
21, 2004) at 02/06/2004 10:26:42 Hello, Just a thought that where appropriate we might profit from the marine industry. Almost all private boats have a battery switch which isolates the battery and alternator. They have found that alternator diodes blow when this switch is opened while the field windings are still energized. The alternator is charging into an open circuit. An internally regulated alternator wired as Z-24 with the alternator disconnect contactor looks to have the same problem. The solution that the marine industry has developed is the Zap-Stop, which appears to be Bob's proposed solution in http://www.aeroelectric.com/articles/Alternator_Failures.pdf Might be something to consider. Make sure you get all of the URL: http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&productId=46596&catalogId=10001&classNum=12105&subdeptNum=544&storeNum=9 Jack Bloodgood Just a Lurker jackb(at)us.ibm.com ________________________________________________________________________________
Date: Feb 06, 2004
From: Richard Tasker <retasker(at)optonline.net>
Subject: Re: 11133 Hersha
What he is saying is that the coil probably uses magnet wire. This wire has a very thin insulation similar to varnish and is similar in color to the copper. You have to scrape this insulation off if you want to solder to the copper wire. Dick Tasker Jan de Jong wrote: > > >"It was nearly impossibe to get solder to stick to the bare copper when >soldering a tinned wire to it." > >You may have to scrape the "bare copper" to get to the bare copper... > >Jan de Jong > ________________________________________________________________________________
From: "James E. Clark" <james(at)nextupventures.com>
Subject: OV Protection for Internally Regulated .. Another
Question
Date: Feb 06, 2004
Thanks Bob. I had overlooked it. James [snip] > > Yup, Figure Z-24 in the back of the AeroElectric Connection > suggests a means for providing (1) absolute control of an > internally regulated alternator and (2) providing ov > protection. The question under consideration now is which, > ________________________________________________________________________________
From: "Kenneth Gresham" <kgresham(at)mtco.com>
Subject: Navigatin lighting
Date: Feb 06, 2004
I would like to know what is required lighting in U.S. for night VFR and later possibly IFR. Is wing lighting with colored front, strobe center, and white at rear of same fixture adequate? If not please give lights and specific locations. I would like to keep wiring to rear of fuselage to a minimum. I intend to run wing tip wiring through a conduit since this is a composite airframe Any other thoughts or suggestions are appreciated. Ken Gresham Europa Kit # A268 Rigging wings ________________________________________________________________________________
From: "Scott Hersha" <shersha(at)fuse.net>
Subject: Re: Navigatin lighting
Date: Feb 06, 2004
Night flying requires navigation lights (red/left, green/right), white tail lights, and an aniti-collision lighting system for the exterior of the airframe. The tail lights can be the aft facing white light that is on many nav light setups. There would be a light fixture on each wingtip with a red or green light forward and the white light aft. These also come (very popular) with a strobe light on the end of the fixture. The strobe lights take the place of the anti-collision light that would otherwise have to located somewhere on the fuselage, making it visible for 360 degrees. You also need adequate lighting to read required flight and engine instruments in the cockpit. No difference for IFR except I think you might also need to have landing light....I wouldn't want to fly at night without them. If you have an Aircraft Spruce catalog, check out the lighting section. There is a good description of required exterior lighting as well as where they need to be mounted for proper coverage. You don't need to have any lights on your tail.....not required. Scott Hersha ----- Original Message ----- From: "Kenneth Gresham" <kgresham(at)mtco.com> Subject: AeroElectric-List: Navigatin lighting > > I would like to know what is required lighting in U.S. for night VFR and later possibly IFR. Is wing lighting with colored front, strobe center, and white at rear of same fixture adequate? If not please give lights and specific locations. I would like to keep wiring to rear of fuselage to a minimum. I intend to run wing tip wiring through a conduit since this is a composite airframe Any other thoughts or suggestions are appreciated. > > Ken Gresham > Europa Kit # A268 Rigging wings > > ________________________________________________________________________________
Date: Feb 06, 2004
From: Dave Morris <dave(at)davemorris.com>
Subject: Re: 11133 Hersha
I used to light a match and flame the end of magnet wire and then the varnish will crumple off into powder and wipe off easily. They may have changed the chemical formulation since I did that last many years ago, but it beat the heck out of sandpaper. Dave Morris At 09:44 AM 2/6/2004, you wrote: > > >What he is saying is that the coil probably uses magnet wire. This wire >has a very thin insulation similar to varnish and is similar in color to >the copper. You have to scrape this insulation off if you want to >solder to the copper wire. > >Dick Tasker > >Jan de Jong wrote: > > > > > > >"It was nearly impossibe to get solder to stick to the bare copper when > >soldering a tinned wire to it." > > > >You may have to scrape the "bare copper" to get to the bare copper... > > > >Jan de Jong > > > > ________________________________________________________________________________
Date: Feb 06, 2004
From: Dave Morris <dave(at)davemorris.com>
Subject: Re: Navigatin lighting
At 04:56 PM 2/6/2004, you wrote: > >Night flying requires navigation lights (red/left, green/right), white tail >lights, and an aniti-collision lighting system for the exterior of the >airframe. The tail lights can be the aft facing white light that is on many >nav light setups. There would be a light fixture on each wingtip with a red >or green light forward and the white light aft. These also come (very >popular) with a strobe light on the end of the fixture. The strobe lights >take the place of the anti-collision light that would otherwise have to >located somewhere on the fuselage, making it visible for 360 degrees. You >also need adequate lighting to read required flight and engine instruments >in the cockpit. No difference for IFR except I think you might also need to >have landing light....I wouldn't want to fly at night without them. If you >have an Aircraft Spruce catalog, check out the lighting section. There is a >good description of required exterior lighting as well as where they need to >be mounted for proper coverage. You don't need to have any lights on your >tail.....not required. >Scott Hersha Also, if you're interested in saving weight, heat, and current, check out the advances in LED technology that are happening. You've probably seen the new car tail lights and traffic signals that use LEDs. Here are just a few references on LEDs that should give you an idea of what's developing and what's possible in experimental aviation: Brightest LEDs are from Lumileds: http://www.lumileds.com/luxeon/products/products_index.html They can be purchased here, but only by phone, and check for what is in stock before getting too excited: http://www.quickar.com/leds.php or from the authorized distributor here: http://www.futureelectronics.com/1033/promos/lumileds/ Tail light kits: http://www.periheliondesign.com/ledlightkits.htm Position lights: http://www.killacycle.com/Lights.htm http://www.periheliondesign.com/ledpositionlights.htm White paper on position lights: http://www.periheliondesign.com/pdf_files/redandgreenledpositionlights.pdf Research: http://members.misty.com/don/led.html http://ledmuseum.home.att.net/ledleft.htm Dave Morris ________________________________________________________________________________
From: "LarryRobertHelming" <lhelming(at)sigecom.net>
Subject: Re: Navigatin lighting
Date: Feb 06, 2004
You might want to pick up an Aircraft Spruce Catalog sometime. It has a nice description of the lighting requirements. Indiana Larry, RV7 Tip-up TMX-O-360 ACS2002 Dynon CNS430 Digitrak On Finish Kit ----- Original Message ----- From: "Kenneth Gresham" <kgresham(at)mtco.com> Subject: AeroElectric-List: Navigatin lighting > > I would like to know what is required lighting in U.S. for night VFR and later possibly IFR. Is wing lighting with colored front, strobe center, and white at rear of same fixture adequate? If not please give lights and specific locations. I would like to keep wiring to rear of fuselage to a minimum. I intend to run wing tip wiring through a conduit since this is a composite airframe Any other thoughts or suggestions are appreciated. > > Ken Gresham > Europa Kit # A268 Rigging wings > > ________________________________________________________________________________
From: "hollandm" <hollandm(at)pacbell.net>
Subject: Shielded wire options
Date: Feb 06, 2004
Thanks Bob, In that case I want to pass along this source of the least expensive wire that will handle this application. They also stock various connectors and antenna wire. http://www.thewireman.com/index.shtml ________________________________________________________________________________
From: Joel Harding <cajole76(at)ispwest.com>
Subject: ic-List:Power supply
Date: Feb 06, 2004
A short time ago a suggestion was given to hook up the power supply to the B- lead to power up the airplane. Is there any need to disconnect the alternator before power is applied? Joel ________________________________________________________________________________
Date: Feb 07, 2004
From: klehman(at)albedo.net
Subject: alternator switch
I still have trouble with the need for absolute alternator control or a need for an alternator switch. I am referring to an internal vr alternator. If ov protection trips then I don't want to reset it in flight unless I suspect a nuisance trip. However nuisance ov tripping is unacceptable so I would want to correct that or remove the ov protection. If diodes short then the ANL is going to blow before I can manually turn off the alternator. If I think that I might have time and opportunity to turn it off before an impending crash then I'm pretty sure that I'll already have the engine shutoff and I don't expect my psru equipped engine to windmill so the alternator will already be dead. At this point I'm leaning toward a manual battery switch that is not on the panel so it can't be accidently turned off and no alternator switch. I'm still thinking about it but such an architecture would also allow me to run the electrically dependant engine loads through the manual batt switch. But heh I'm still listening ;) ... Another option that I'd like is for a reasonable cost replacement for the heavy (weight and current) contactor that seems to be required to add ov protection to my 40 amp alternator. With high current silicon these days, I'd almost think that there would be a way of directly crowbar shorting/blowing the B lead ANL. Hmmm now that I think about it there might even be some 100+ amp scr's in my junk box... I think they came from an AC/DC welder. Fortunately a lighter S704-1 relay seems to be acceptable for my 20 amp second alternator. Ken Yup, Figure Z-24 in the back of the AeroElectric Connection suggests a means for providing (1) absolute control of an internally regulated alternator and (2) providing ov protection. ________________________________________________________________________________
Date: Feb 07, 2004
From: Jerzy Krasinski <krasinski(at)direcway.com> alternators
Subject: Re: OV protection for internally regulated
alternators alternators Jack Bloodgood wrote: > > >Hello, > >Just a thought that where appropriate we might profit from the marine >industry. Almost all private boats have a battery switch which isolates the >battery and alternator. They have found that alternator diodes blow when >this switch is opened while the field windings are still energized. The >alternator is charging into an open circuit. > > From the picture it looks that they are selling $0.70 transorb for $27.99. Jerzy ________________________________________________________________________________
Subject: Re: Shielded wire options
From: John Schroeder <jschroeder(at)perigee.net>
Date: Feb 07, 2004
You can buy RG400 Coax from Wiremaster for $0.86/ft (Min. of 100 ft order) vs. $1.50 per ft. for a 100' buy at the source listed below. Wiremasters also has every gauge of 22759 and in almost every color for prices below any I have found. Most buys must be 100' min. They also have milspec M27500-xx TG x T14 (shielded hookup wire). Their 22 AWG 5 conductor is $.94/ ft and their 3 conductor (M27500-22TG3T14) is $.26 per foot. Call them at 800 635-5342. Ask for Deb Sullivan. Or email her at dsullivan(at)wiremasters.net Cheers, John > In that case I want to pass along this source of the least expensive > wire that will handle this application. They also stock various > connectors and antenna wire. > > http://www.thewireman.com/index.shtml > ________________________________________________________________________________
From: "Terry Teer" <threet(at)telepak.com>
Subject: Wing wiring
Date: Feb 07, 2004
Just about completed wings on a RV-7 and need some help. Installing landing light, position light, strobes (in fiberglass tips), nav/com antenna wiring (RG-400), also a roll servo for the a/p. Should I run all the wires through the 3/4 conduit or should some of them be separated from the rest? Also on the strobe heads...the whelen strobes say to ground the shielding to the power supply but in Bob's manual it says to ground the shielding wire to the strobe heads if mounting in plastic tips. What about it list? This is my second OBAM and the first to have more advanced equipment and need some advice. Regards, Terry Ackerman, MS ________________________________________________________________________________
From: "Gary Casey" <glcasey(at)adelphia.net>
Subject: RE: even more ov discussion
Date: Feb 08, 2004
<> Here's an idea along those lines. If you have a single large (normal size) battery and 2 alternators, make one be of very modest output, like 40 amps, and the other a reasonable backup, like 8 or 20 amps. The failure mode will be one of them going "ov." At that low capacity you will have plenty of warning and will be able to increase the load (in my case 160W of landing lights, pitot heat, vent blower) to reduce or even eliminate the excess charge current to the battery. I'm not sure I'm recommending it, but it does seem like a reasonable approach. Gary Casey ________________________________________________________________________________
Date: Feb 08, 2004
From: Michel Therrien <mtherr(at)yahoo.com>
Subject: Battery Bus Power Cut Relay - good idea?
Hi Bob! I designed a modification this evening for my electrical system. It is a dual-battery, single alternator system for an automobile conversion engine (converted for dual ignition). I would like to know what you think of it. Essentially, I propose a relay to cut the power from the battery to the battery bus. That relay would be wired so I use the normally-closed circuit and to open (cut) the circuit when the coil is energized. See (relevant portion of my electrical schema): http://mthobby.pcperfect.com/mods/wirebook040208a.gif A little modification to this would allow to cut all voltage in the cabin from the flick of an emergency cut-off switch. See: http://mthobby.pcperfect.com/mods/wirebook040208b.gif Why this? 1. As per AeroElectric Connection, I want anything that keeps the engine running to receive energy even if I turn off the Master switch(es). Ign 1, 2 and fuel pumps are on battery bus. And I want that engine to continue working even if I make fool operation (like turning off masters and then, on any switch that would energize the engine). 2. It is recommended to use a relay to energize any circuit from the B-Bus that is fused at more than 5amps. The reasoning is that we want to keep sparks as small as possible when the aircraft is disingrating during a crash. I'm not an expert at this, but I think that no matter the size of a spark, the risk is pretty much the same. 3. Two advisors here tell me it's important to be able to cut all electrical power should I be in a situation were crashing is a real possibility (ex.: lost engine, going down in a rough field). I think the modification should be reliable (but not being an expert, this is why I ask for your opinion) as I will be using the normally closed circuit from the relay (b-bus ON when relay is NOT energized). It will also be flexible as I still can turn off the masters, use the battery busses and if needed, with the second diagram, turn off all electrical system at the flick of a single switch (protected with an emergency switch cover). More over, this change addresses your recommendation of using relays for 5+amp all circuits with a single relay. Please let me know what you think. Regards, Michel ===== ---------------------------- Michel Therrien CH601-HD, C-GZGQ http://mthobby.pcperfect.com/ch601 http://www.zenithair.com/bldrlist/profiles/mthobby http://pages.infinit.net/mthobby __________________________________ http://taxes.yahoo.com/filing.html ________________________________________________________________________________
Date: Feb 08, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: ectric-List:Power supply
> > >A short time ago a suggestion was given to hook up the power supply to >the B- lead to power up the airplane. Is there any need to disconnect >the alternator before power is applied? No. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Feb 08, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: RE: even more ov discussion
> ><need for an alternator switch. I am referring to an internal vr >alternator.>> > >Here's an idea along those lines. If you have a single large (normal size) >battery and 2 alternators, make one be of very modest output, like 40 amps, >and the other a reasonable backup, like 8 or 20 amps. The failure mode will >be one of them going "ov." At that low capacity you will have plenty of >warning and will be able to increase the load (in my case 160W of landing >lights, pitot heat, vent blower) to reduce or even eliminate the excess >charge current to the battery. I'm not sure I'm recommending it, but it >does seem like a reasonable approach. Why put ov management on the pilots list of duties when it so easy to make it automatic? Bob . . . ________________________________________________________________________________
Date: Feb 08, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> regulated alternators
Subject: Re: OV protection for internally
regulated alternators regulated alternators > alternators > > >Jack Bloodgood wrote: > > > > > > >Hello, > > > >Just a thought that where appropriate we might profit from the marine > >industry. Almost all private boats have a battery switch which isolates the > >battery and alternator. They have found that alternator diodes blow when > >this switch is opened while the field windings are still energized. The > >alternator is charging into an open circuit. > > > > > > From the picture it looks that they are selling $0.70 transorb for $27.99. >Jerzy I think you're right . . . and a transorb is exactly what I'm going to propose. But I can't make a recommendation until after we've tested the alternator and sized the part. Bob . . . ________________________________________________________________________________
Date: Feb 08, 2004
From: frequent flyer <jdhcv(at)yahoo.com>
Subject: Re: RE: even more ov discussion
> Why put ov management on the pilots list of > duties > when it so easy to make it automatic? > > Bob . . . Hey guys, if you have an internally regulated alternator and OV protection, use the alternator. If you ever do have an overvoltage condition that blows the alternator replace it with one that is not internally regulated. If it never happens it doesn't matter. I think you're wasting too much time worrying about it. fwiw. Jack __________________________________ http://taxes.yahoo.com/filing.html ________________________________________________________________________________
Date: Feb 08, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: alternator switch
> >I still have trouble with the need for absolute alternator control or a >need for an alternator switch. How so? If you hardwire the alternator to the airplane and it does go into an ov condition, how would you expect to manage the results that follow? > I am referring to an internal vr >alternator. If ov protection trips then I don't want to reset it in >flight unless I suspect a nuisance trip. However nuisance ov tripping is >unacceptable so I would want to correct that or remove the ov >protection. Nuisance tripping of the crowbar ov module is rare but it HAS happened and at higher rates than real ov tripping. I'd have no problem with resetting an ov trip one time . . . and then watching to see if any second trip is associated with some action. (We could do it on Bonanzas by turning landing and taxi lights on at the same time - I unaware of any dominant nuisance trip modes since we modified the system to accommodate eccentricities of the Bonanza'a super bouncy switches). >If diodes short then the ANL is going to blow before I can >manually turn off the alternator. If I think that I might have time and >opportunity to turn it off before an impending crash then I'm pretty >sure that I'll already have the engine shutoff and I don't expect my >psru equipped engine to windmill so the alternator will already be dead. I'm confused . . . why should your engine die just 'cause the alternator misbehaves? Diodes shorting are also very rare, even more rare than real ov trips. >At this point I'm leaning toward a manual battery switch that is not on >the panel so it can't be accidently turned off and no alternator switch. >I'm still thinking about it but such an architecture would also allow me >to run the electrically dependant engine loads through the manual batt >switch. But heh I'm still listening ;) ... First, keep in mind that the "OV TRIP PROBLEM" seems to be shaping up as a condition limited to rebuilt internally regulated alternators with possible after-market regulators having poor design. I fully expect the "fix" to be simple and probably inexpensive enough for it to be included in the Figure Z-24 design for inclusion on ALL internally regulated alternators irrespective of pedigree. If this turns out to be true, then all of this discussion is making a mountain out of a mole hill. >Another option that I'd like is for a reasonable cost replacement for >the heavy (weight and current) contactor that seems to be required to >add ov protection to my 40 amp alternator. With high current silicon >these days, I'd almost think that there would be a way of directly >crowbar shorting/blowing the B lead ANL. I've looked at direct crowbar of the alternator b-lead. You DON'T want to do this with an ANL . . . we'd probably recommend a relatively robust but MUCH faster JJS/JJN series fuse at 100A or so. This still has pitfalls. Recall that a crowbar ov module faulted downstream of a 5A breaker gets us trip responses in the tens of milliseconds with a 300A fault. If we expected similar speeds from a direct crowbar of the b-lead, we're going to looking a fault currents on the order of 1000A or more. The BATTERY is an integral component of the crowbar ov trip system. We want it do deliver fault currents high enough to get a speedy trip while minimizing disruption of power to the rest of the airplane. Trip currents necessary to open the b-lead fuse are substantially higher than those required to open a 5A control breaker. > Hmmm now that I think about it >there might even be some 100+ amp scr's in my junk box... I think they >came from an AC/DC welder. Fortunately a lighter S704-1 relay seems to >be acceptable for my 20 amp second alternator. I'm not saying what you're suggesting can't work but there's more to it than deciding to "crowbar that fuse instead of this breaker" . . . I've already looked at some of the issues and there are aspects of b-lead crowbar that push our design in the wrong direction. The goal is to shut the alternator down with minimum stress on all parts involved including battery and other devices soon to be dependent on the battery for power. In fact, Z-24 would work very nicely with a 2A control breaker. THAT's indeed a move in the right direction. Yes, the contactor adds some weight . . but keep in mind that the weight penalty of the disconnect contactor (12 oz) is less than the variability of popular alternators being considered as alternatives to the MUCH heavier alternators in certified aircraft. If you did the mod to run an external regulator, you add 7-10 ounces for the regulator. So, after saving 3-6 pounds by choosing not to use contemporary certified alternators, then the delta weight between externally regulated and internally regulated alternator installations is on the order of 2 to 5 ounces. Bob . . . ________________________________________________________________________________
Date: Feb 09, 2004
From: Jim Oke <wjoke(at)shaw.ca>
Subject: Re: RE: even more ov discussion
Well, that's about the size of it. Alternators of the sort being discussed are quite cheap compared to the expensive avionics that the OV device is intended to protect. Worrying about a $75 alternator when the real money is in the $1000 radios and the $3000 (and on up) GPS units is wasted time. The whole idea of OV protection is to look after the expensive avionics and the aircraft wiring and not to preserve some flaky alternator to live another day. (Most modern automotive alternators are not flaky - and are built to withstand all sorts of abuse from mechanically inept drivers on a "they don't even have to know it's there" basis.) Jim Oke Wpg., MB ----- Original Message ----- From: "frequent flyer" <jdhcv(at)yahoo.com> Subject: Re: AeroElectric-List: RE: even more ov discussion > > > > Why put ov management on the pilots list of > > duties > > when it so easy to make it automatic? > > > > Bob . . . > Hey guys, if you have an internally regulated > alternator and OV protection, use the alternator. If > you ever do have an overvoltage condition that blows > the alternator replace it with one that is not > internally regulated. If it never happens it doesn't > matter. I think you're wasting too much time worrying > about it. fwiw. > > Jack > ________________________________________________________________________________
From: "Dale Martin" <niceez(at)cableone.net>
Subject: Re: battery / alternator switch
Date: Feb 09, 2004
In the schematic's for the all electric airplane (Z-13) and the Generic Light Aircraft Electrical System (Z-11) both depicts a Battery / Alt switch # 2-10 - (2 dash 10). However, in the switches, relays and contactors pages it says switch 2 dash 3 is recommend for the combination Battery Master/alternator-field switching. Which one is correct? BTW, I have just successfully removed all wires from my 28volt IFR LEZ (with exception of the strobe and nav light wires in the wings) after 18 years and 1,100 + hours of flying. Talk about scary.... This is for a much simplier electrical system and full panel upgrade. No more vacuum system for me and no more 28 to 14 inverter. Everything is 28 volt. One thing I found amazing is how many different places I had ground wires terminating. I built my own ground bus only because the ones from B&C do not appear to be mechanically attached to the brass and my two boys needed some practice using the drill press using brass. The total price was less then twenty bucks with free labor. Also this system will only be using one alternator. Using one mag and one E.I is enough engine redundancy with the lone battery for essential bus. I believe in the good battery theory and checking it twice per year for acid specific gravity and over all battery condition and replacing it as needed. Thanks for your help and comments in advance, Dale Martin Lewiston, ID LEZ-235 ________________________________________________________________________________
From: "Dan Branstrom" <danbranstrom(at)verizon.net>
Subject: For Bob, Comment?
Date: Feb 09, 2004
There is an upcoming program on Public Broadcasting: NOVA: The Deadly Legacy Of an inflight fire caused by electrical arcing. Because the article is too long to send out, I'm referring you to the press release that can be seen on the Mon, 09 Feb '04 online edition of Aero News Network http://aero-news.net/index.cfm ________________________________________________________________________________
From: "Dan Branstrom" <danbranstrom(at)verizon.net>
Subject: For Bob: Comment?
Date: Feb 09, 2004
Here is a more precise address for the article. References to the ANN website will get different stories every day. http://aero-news.net/index.cfm?ContentBlockIDca2fd051-b7b7-4fe2-94dc-def5c536d3d5& There is an upcoming program on Public Broadcasting: NOVA: The Deadly Legacy Of an inflight fire caused by electrical arcing. (The web address that follows is the general one for ANN. To see the article, you would have to refer to the date. Because the article is too long to send out, I'm referring you to the press release that can be seen on the Mon, 09 Feb '04 online edition of Aero News Network http://aero-news.net/index.cfm ________________________________________________________________________________
From: BAKEROCB(at)aol.com
Date: Feb 09, 2004
Subject: Wing wiring
AeroElectric-List message previously posted by: "Terry Teer" <> 2/8/2004 Hello Terry, The cable from Whelen has foil shielding and a drain wire in addition to the other wires. Just connect the drain wire to the base of the (central?) power supply like Whelen says. See previous post below. There are follow up postings that hash this out some more that you can read using the search capability if you desire. 'OC' 6/29/2003 Hello Bob Nuckolls and Bret Ferrell, I'd like to flog this horse a few more lashes. 1) Bob Nuckolls really says the drain wire should be attached at both ends on a composite aircraft? But not on a metal aircraft? Why? 2) When one receives the strobe light installation kit from Whelen the cable already has two AMP plastic 3 wire connectors attached, one on each end. These connectors are the ones that plug into the mating 3 wire connectors at the strobe light ends. After cutting the cable somewhere in the middle and snaking those two cut ends through the airframe to the vicinity of the strobe power supply one installs the other two (different) appropriate 3 wire connectors provided by Whelen and plugs the cables into the power supply. 3) The installation instructions say that the drain wire should be connected to the housing / mounting of the power supply. Easy enough to do by leaving the drain wire longer when you cut the cable, strip it, and install the 3 wire connectors that plug into the power supply. 4) But out at the strobe light end of the cable where the Whelen installed connectors are, Whelen has left no access to the drain wire. I suppose one could cut back the plastic covering, remove the aluminum shield, attach a short wire to the now exposed drain wire, and then attach that short wire to some metal part of the strobe light housing, but I find this action both puzzling and unnecessary. 5) Whelen has thousands of these units in service throughout the skies mounted on both metal surfaces and composite wing tips. I am unaware of any need to go through the additonal effort of connecting the drain wire to the metal light housing out at the strobe light end. Can anyone show me different? ________________________________________________________________________________
From: "ivorphillips" <ivor(at)ivorphillips.flyer.co.uk>
Subject: Re: For Bob, Comment?
Date: Feb 09, 2004
> There is an upcoming program on Public Broadcasting: NOVA: The Deadly It deals with an inflight fire caused by electrical arcing. > Have seen this program a couple of weeks ago, It make you wonder how a commercial aircraft can have its wiring set up in such away that the pilots were unable to isolate the entertainment system from the main cockpit Bus! No breakers tripped to alleviate the problem, just smoke from behind panelling, I find it hard to believe that circuits are shared without proper regards too overload wire protection, Its criminal that so many folk lost their lives due to a preventable wiring short circuit. Ivor Phillips Europa xs ________________________________________________________________________________
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Load dump issues
Date: Feb 09, 2004
I have watched this discussion and am concerned that the issue/facts/solution is going off track a little. Load dump is NOT unique to internally regulated alternators. ANY alternator can and will exhibit load dump when wired such that the load can be removed from the "B" lead when the alternator is generating power. IE internal/external/new/old/rebuilt are all the SAME with regard to Load Dump concerns. All alternators, regardless of design, need protection or they can dump damaging loads either back to the alternator or to the expensive avionics depending on what opened and where. Designs that disconnect the "B" lead when OVP is detected are great as long as there are Zero false trips. Bob has said many times that his OVP can and does (while very rare) false trip. This can result in alternator damage due to a false trip and not acceptable to me. Alternator damage with a real OVP trip is not an issue as the alternator has already failed. There are more modern OVP I/C's that have provision for not false tripping on narrow spikes as they have adjustable delay to trip times. I suggest that this design approach be used to prevent a OVP protection device from causing damage from a not quite perfect design. The Linear LTC1696 is inexpensive and is designed to provide reliable OVP with minimal additional parts. Eric Jones has such a OVP design and I highly recommend it IF you are concerned about False trips. It's already designed and available to us. http://www.periheliondesign.com/ If the alternator is generating say 50 amps and 40 amps are going to the battery and 10 amps to the rest of the system and the battery is disconnected the alternator output voltage (and the acft system bus) will rise until the 40 amp excess is loaded. This can result in a high voltage spike that is not stopped with OVP devices that shut off the regulator (too late action). Thus potential damage to avionics etc is likely if there is a large enough load dump. The damaging current is already there and thus its too late for a working regulator with or without OVP design to stop the energy pulse. On the other hand if the battery is fully charged there will be near zero current that is unloaded and no load dump to worry about if the battery is suddenly off line. Also most alternator regulators will work properly with out the battery if there is enough load on the system. Some may require a large cap say 25,000 MFD to stabilize the regulator without the battery present. Load dump is not new; some 20+ years ago I/C mfgrs tried to convince auto makers to incorporate Load dump protection in their alternators. This effort was unsuccessful (at the time) as this is not an issue with autos, as in autos the "B" lead is always directly wired to the battery. Thus there is no "switch" to be accidentally opened to cause load dump action. Also there is no OVP included as its rare and not a concern in the auto mfgrs mind. At least a couple of years ago I was unable to find ANY auto mfgr alternator that protected against load dump. ANY design that uses an alternator and has a requirement to be disconnected from the battery (as in acft) needs to be fool proof. Ideally there should be no way to do it with the accidental throw of a switch as the current Z-xx diagrams seem allow. At least without considering the potential of damaging load dump. Again this info (load dump) and design need is decades old and I wonder why its just becoming an issue on this list. What we have is the USE of an auto alternator that was designed to be always directly connected to the battery. In a different application with additional design requirements to consider those new requirements have not peen fully considered. Perhaps this is a continuation of what Spam can mfgrs did when the generator was replaced with an alternator and the replacement was not totally though out. Also at the time regulators were mechanical and avionics had vacuum tubes and both are much more immune to transients that today's solid state devices. Bob has suggested that NEW alternators have such protection and so Bob please let us know specifically which NEW alternators have such protection built in so we can consider them for our use. Then there are comments about rebuilt alternators being inferior. Perhaps some are but then many are just as good as the original NEW alternator in all respects. As for testing and evaluation of TVS devices for load dump protection and getting your stamp of approval why do it?? There are such devices available that are designed, tested and industry approved for this specific application and rated for the largest alternator likely to be found on any acft. The ST LDP24A is one and rated for 500amp. I do not understand the need for additional testing in this case. The Boaters have long since solved the problem and so why are we still investigating it?? With all due respect my comments are intended to be helpful. Paul ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: alternator switch > > > > >I still have trouble with the need for absolute alternator control or a > >need for an alternator switch. > > How so? If you hardwire the alternator to the airplane > and it does go into an ov condition, how would you > expect to manage the results that follow? > > > I am referring to an internal vr > >alternator. If ov protection trips then I don't want to reset it in > >flight unless I suspect a nuisance trip. However nuisance ov tripping is > >unacceptable so I would want to correct that or remove the ov > >protection. > > Nuisance tripping of the crowbar ov module is rare but it > HAS happened and at higher rates than real ov tripping. > I'd have no problem with resetting an ov trip one time . . . > and then watching to see if any second trip is associated with > some action. (We could do it on Bonanzas by turning landing > and taxi lights on at the same time - I unaware of any dominant > nuisance trip modes since we modified the system to accommodate > eccentricities of the Bonanza'a super bouncy switches). > > >If diodes short then the ANL is going to blow before I can > >manually turn off the alternator. If I think that I might have time and > >opportunity to turn it off before an impending crash then I'm pretty > >sure that I'll already have the engine shutoff and I don't expect my > >psru equipped engine to windmill so the alternator will already be dead. > > I'm confused . . . why should your engine die just 'cause the > alternator misbehaves? > > Diodes shorting are also very rare, even more rare than real > ov trips. > > >At this point I'm leaning toward a manual battery switch that is not on > >the panel so it can't be accidently turned off and no alternator switch. > >I'm still thinking about it but such an architecture would also allow me > >to run the electrically dependant engine loads through the manual batt > >switch. But heh I'm still listening ;) ... > > First, keep in mind that the "OV TRIP PROBLEM" seems to be shaping > up as a condition limited to rebuilt internally regulated alternators > with possible after-market regulators having poor design. I fully > expect the "fix" to be simple and probably inexpensive enough for > it to be included in the Figure Z-24 design for inclusion on ALL > internally regulated alternators irrespective of pedigree. If this > turns out to be true, then all of this discussion is making a mountain > out of a mole hill. > > > >Another option that I'd like is for a reasonable cost replacement for > >the heavy (weight and current) contactor that seems to be required to > >add ov protection to my 40 amp alternator. With high current silicon > >these days, I'd almost think that there would be a way of directly > >crowbar shorting/blowing the B lead ANL. > > > I've looked at direct crowbar of the alternator b-lead. You > DON'T want to do this with an ANL . . . we'd probably recommend > a relatively robust but MUCH faster JJS/JJN series fuse at 100A > or so. This still has pitfalls. Recall that a crowbar ov module > faulted downstream of a 5A breaker gets us trip responses in > the tens of milliseconds with a 300A fault. If we expected > similar speeds from a direct crowbar of the b-lead, we're going > to looking a fault currents on the order of 1000A or more. > > The BATTERY is an integral component of the crowbar ov trip system. > We want it do deliver fault currents high enough to get a speedy > trip while minimizing disruption of power to the rest of the > airplane. Trip currents necessary to open the b-lead fuse are > substantially higher than those required to open a 5A control > breaker. > > > Hmmm now that I think about it > >there might even be some 100+ amp scr's in my junk box... I think they > >came from an AC/DC welder. Fortunately a lighter S704-1 relay seems to > >be acceptable for my 20 amp second alternator. > > I'm not saying what you're suggesting can't work but > there's more to it than deciding to "crowbar that fuse > instead of this breaker" . . . I've already looked at > some of the issues and there are aspects of b-lead > crowbar that push our design in the wrong direction. > > The goal is to shut the alternator down with minimum > stress on all parts involved including battery and other > devices soon to be dependent on the battery for power. > In fact, Z-24 would work very nicely with a 2A control > breaker. THAT's indeed a move in the right direction. > > Yes, the contactor adds some weight . . but keep in > mind that the weight penalty of the disconnect contactor > (12 oz) is less than the variability of popular alternators > being considered as alternatives to the MUCH heavier > alternators in certified aircraft. If you did the mod > to run an external regulator, you add 7-10 ounces for > the regulator. So, after saving 3-6 pounds by choosing > not to use contemporary certified alternators, > then the delta weight between externally regulated > and internally regulated alternator installations is > on the order of 2 to 5 ounces. > > Bob . . . > > ________________________________________________________________________________
Date: Feb 09, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Kapton insulated wire . . . NOT a OBAM aircraft
issue > > >There is an upcoming program on Public Broadcasting: NOVA: The Deadly >Legacy Of Swiss Air 111 that will be airing on February 17th at 8:00 >EST. It deals with an inflight fire caused by electrical arcing. > >Because the article is too long to send out, I'm referring you to the >press release that can be seen on the Mon, 09 Feb '04 online edition of >Aero News Network http://aero-news.net/index.cfm Thanks for the heads up. I'll try to catch the program. I looked over the linked article. It's writing typical of "journalists" who don't know enough about the art and science of the topic to write intelligently and accurately about it. It will be interesting see how Nova presents it. There was a lot of worry wash thrown about with paragraphs like this: "NOVA reports the electrical arc, generating up to 12,000 degrees (F), ignited the supposedly fireproof mylar insulation surrounding the interior of the aircraft. The program quotes experts who say, in aircraft where there's as much as 150 miles of wire on board, there can be up to 1500 cracks in wiring insulation. Couple that with the type of condensation typical in the upper compartments of an aircraft in flight and NOVA's experts suggest the possibility for a disastrous in-flight fire event are extraordinary." The discussion then shifts back to failures of policy and procedures systems to deal with materials used in insulation and other parts with emphasis on proposals to improve ability to detect and suppress fires. I didn't pick up on a single statement dealing with why an airplane with 150 miles of wire should be reasonably expected to have 1500 cracks . . . gee, the B-52's I worked on in 1961 had 500 miles of wire . . . Hmmmm . . . should we have told crews that their airplane had a good chance of having 5,000 cracks in the wiring? The 12,000 degrees (F of course . . . that's only 8,300 degrees C but not nearly as impressive a number) statement is suspect and not particularly relevant without explaining what the total energy budget is and how that bundle of energy gets from the arc to surrounding materials. Every time you open the pitot heater switch on your airplane, an arc of very high temperature is generated . . . but with total energy measured in millijoules and totally contained between two rather cool contacts. A complete non-issue when the complete picture is examined . . . but I could write a paragraph describing the event that would have many builders swearing never to install a pitot heater on their airplane. The article didn't mention Kapton insulation on wires . . . which I've heard was involved in this accident. See: http://www.flight592.com/Flight592Discussion-Current/_disc5/00000158.htm http://www.iasa.com.au/folders/Safety_Issues/Aircraft_Wire/CBCTranscript.html Here's a piece the takes a better than average whack at the science: http://www.eng.buffalo.edu/Courses/ce435/2001ZGu/Kapton_Wires/KaptonWiresReport.htm I was warned about Kapton in 1985 when we were selecting wire for the GP-180 at Lear and frustrated with the State Department's prohibition against exporting 22759 wire in a product. We certainly didn't want to limit the sales of our airplanes to US customers. I was told back then that the Navy was having to wrap wires at the hinges of folding-wing carrier based aircraft with Scotch 33 tape to replace Kapton that flaked off in the salt-air environment. I doubt the B-52 had a few dozens of cracks in wiring much less 5,000. Airplanes wired with Tefzel have to rank among the very best we know how to do for ease of installation, reasonable cost, and well demonstrated service life. The Swiss Air 111 accident will make good worry-fodder for Nova and others for years to come but I'll be completely amazed if anyone finally burrows down to the real root cause and makes it public. It's more useful to bash the policy and procedures guys for what they're NOT doing to make us "safer" than to exposed the original designers and installers of a marginally suitable product and make them gut those airplanes and rewire them. Characteristics of the mylar insulation and duct caps don't worry me nearly so much as the kind of insulation used on the wires. Bob . . . ________________________________________________________________________________
Date: Feb 09, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: battery / alternator switch
> >In the schematic's for the all electric airplane (Z-13) and the Generic >Light Aircraft Electrical System (Z-11) both depicts a Battery / Alt switch ># 2-10 - (2 dash 10). However, in the switches, relays and contactors pages >it says switch 2 dash 3 is recommend for the combination Battery >Master/alternator-field switching. > >Which one is correct? Either one works. A 2-3 combined with a PULLABLE field supply breaker in the crowbar ov protection circuit gives the same functionality as a 2-10. It's no big deal to have the alternator ON during cranking . . . so, a 2-3 works. -EITHER- the mid-position on a 2-10 switch -OR- pulling the field circuit breaker allows battery only ops for ground maintenance or turning off a mis-behaving alternator in flight. It's not a matter of CORRECTNESS but a matter of PREFERENCE. >BTW, I have just successfully removed all wires from my 28volt IFR LEZ (with >exception of the strobe and nav light wires in the wings) after 18 years and >1,100 + hours of flying. Talk about scary.... This is for a much simplier >electrical system and full panel upgrade. No more vacuum system for me and >no more 28 to 14 inverter. Everything is 28 volt. Are you going to 14v or staying 28v? >One thing I found amazing is how many different places I had ground wires >terminating. I built my own ground bus only because the ones from B&C do >not appear to be mechanically attached to the brass . . . How so? >and my two boys needed >some practice using the drill press using brass. The total price was less >then twenty bucks with free labor. Also this system will only be using one alternator. Using one mag and one >E.I is enough engine redundancy with the lone battery for essential bus. I >believe in the good battery theory and checking it twice per year for acid >specific gravity and over all battery condition and replacing it as needed. Do you have a vacuum pump pad with nothing mounted on it? For $300 and 4 pounds you can have a SECOND engine driven power source. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
From: "Ned Thomas" <315(at)cox.net>
Subject: Battery Charger
Date: Feb 09, 2004
I am looking at buying a float charger for my 24volt spam can. This spam can has an always hot battery bus with the the ships clock on it. I was concerned about the following marketing statement as to whether it might harm the clock. Anyone care to comment? Thanks, Ned "High-frequency pulse breaks down sulphated crystals that prevent batteries from holding a full charge." for more: http://www.batterymart.com/battery.mv?p=VDC-24021 ________________________________________________________________________________
Date: Feb 09, 2004
From: f1rocket(at)telus.net
Subject: Z12 e-bus questions
Hi all (Bob), I'm planning on using a Z-12 type system on my Rocket. One battery, two alternators. I notice the e-bus alternate feed is through a 7 A (fuse?) via a 16 AWG wire. Two questions: For peace of mind would a breaker be the best way to go here? I'm thinking that I can easily overload the 7 amps just with the e-bus as described in Z-11. The plane will be outfitted for night flying, and needs a fuel booster pump. So if I end up with more than 7 A (which either I will have, or be very close to) when I loose the main power (assuming two dead alternators), and throw the switch, at least I can get smart, shed load and reset the breaker. For the most part though, I plan on using fuses, because I too have never reset a breaker were there wasn't a problem that resetting the breaker actually helped, and I plan on having each circuit with it's own fuse. Second question: Why only 7 amp protection device off the batter bus? The wire should be able to handle 12 amps? So why not use the protection device to protect the wire, since each of the devices coming off the e-bus will be protected on it's own? Thanks in advance, and also for all the past advice. Jeff ________________________________________________________________________________
From: "Dale Martin" <niceez(at)cableone.net>
Subject: Re: battery / alternator switch
Date: Feb 09, 2004
Bob says, > Do you have a vacuum pump pad with nothing mounted on it? > For $300 and 4 pounds you can have a SECOND engine driven > power source. > > Bob . . . I think you mean a Third source. (Battery =1, Alt =2, Second Alt = 3) I like the fact that I get 4 horsepower back at cruise RPM that the Vacuum pump stole. > Are you going to 14v or staying 28v? I will keep 28 v due to the wire size I use are smaller and paid for! And have a second full size Alternator on the shelf. But to your credit I did consider it but..... then would have to change the starter, Alt, Nav-Com 1, landing light, strobe power unit and all the bulbs not to mention the LR3. Your talking over $2000 bucks and accepting peanuts for some of the equipment I have now. BTW, I have always started the engine with the Alt off. One thing I think is an error IMHO is not using separate Ignition Switches either Guarded or Locking toggle switch for magneto's and especially the older LSE electronic ignitions. When the LSE E.I. are turned on they fire all the plugs at once - Yikes ! May not be a good idea to do this at any RPM. If you were to bump on off in-flight and turn it back on... and it fired say 65 BTDC..... That would really mess things up. Klaus warned me about it. On the alternator thread ....... If the C/B on the LR3 field wire were pulled (engine running) is the Alt able to still send out power just not regulated? If it does, that is not good. I was taught without the field there is no power. Thanks for your comments, Dale Martin Lewiston, ID LEZ-235 ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: battery / alternator switch > > > > >In the schematic's for the all electric airplane (Z-13) and the Generic > >Light Aircraft Electrical System (Z-11) both depicts a Battery / Alt switch > ># 2-10 - (2 dash 10). However, in the switches, relays and contactors pages > >it says switch 2 dash 3 is recommend for the combination Battery > >Master/alternator-field switching. > > > >Which one is correct? > > Either one works. A 2-3 combined with a PULLABLE field supply breaker > in the crowbar ov protection circuit gives the same functionality as > a 2-10. > > It's no big deal to have the alternator ON during cranking . . . so, > a 2-3 works. > > -EITHER- the mid-position on a 2-10 switch -OR- pulling the field > circuit breaker allows battery only ops for ground maintenance or turning > off a mis-behaving alternator in flight. It's not a matter of CORRECTNESS > but a matter of PREFERENCE. > > > >BTW, I have just successfully removed all wires from my 28volt IFR LEZ (with > >exception of the strobe and nav light wires in the wings) after 18 years and > >1,100 + hours of flying. Talk about scary.... This is for a much simplier > >electrical system and full panel upgrade. No more vacuum system for me and > >no more 28 to 14 inverter. Everything is 28 volt. > > Are you going to 14v or staying 28v? > > >One thing I found amazing is how many different places I had ground wires > >terminating. I built my own ground bus only because the ones from B&C do > >not appear to be mechanically attached to the brass . . . > > How so? > > >and my two boys needed > >some practice using the drill press using brass. The total price was less > >then twenty bucks with free labor. > > Also this system will only be using one alternator. Using one mag and one > >E.I is enough engine redundancy with the lone battery for essential bus. I > >believe in the good battery theory and checking it twice per year for acid > >specific gravity and over all battery condition and replacing it as needed. > > Do you have a vacuum pump pad with nothing mounted on it? > For $300 and 4 pounds you can have a SECOND engine driven > power source. > > Bob . . . > > ----------------------------------------- > ( Experience and common sense cannot be ) > ( replaced with policy and procedures. ) > ( R. L. Nuckolls III ) > ----------------------------------------- > > ________________________________________________________________________________
Date: Feb 09, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Battery Bus Power Cut Relay - good idea?
> >Hi Bob! > >I designed a modification this evening for my >electrical system. It is a dual-battery, single >alternator system for an automobile conversion engine >(converted for dual ignition). > >I would like to know what you think of it. >Essentially, I propose a relay to cut the power from >the battery to the battery bus. That relay would be >wired so I use the normally-closed circuit and to open >(cut) the circuit when the coil is energized. >1. As per AeroElectric Connection, I want anything >that keeps the engine running to receive energy even >if I turn off the Master switch(es). Ign 1, 2 and >fuel pumps are on battery bus. And I want that engine >to continue working even if I make fool operation >(like turning off masters and then, on any switch that >would energize the engine). > >2. It is recommended to use a relay to energize any >circuit from the B-Bus that is fused at more than >5amps. The reasoning is that we want to keep sparks >as small as possible when the aircraft is disingrating >during a crash. I'm not an expert at this, but I >think that no matter the size of a spark, the risk is >pretty much the same. > >3. Two advisors here tell me it's important to be able >to cut all electrical power should I be in a situation >were crashing is a real possibility (ex.: lost engine, >going down in a rough field). > >I think the modification should be reliable (but not >being an expert, this is why I ask for your opinion) >as I will be using the normally closed circuit from >the relay (b-bus ON when relay is NOT energized). It >will also be flexible as I still can turn off the >masters, use the battery busses and if needed, with >the second diagram, turn off all electrical system at >the flick of a single switch (protected with an >emergency switch cover). > >More over, this change addresses your recommendation >of using relays for 5+amp all circuits with a single >relay. I don't like putting the least reliable single component in a system (relay/contactor) in position to be single point of failure for all the battery bus. Recommend you use 5A or less fuse for circuits will run from these small fuses . . . and add INDIVIDUAL disconnect relays for each item over that amount. Leave the battery bus integrity un-compromised by leaving it firmly attached to the battery. Bob. . . ________________________________________________________________________________
Date: Feb 09, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Wing wiring
> >Just about completed wings on a RV-7 and need some help. Installing >landing light, position light, strobes (in fiberglass tips), nav/com >antenna wiring (RG-400), also a roll servo for the a/p. Should I run all >the wires through the 3/4 conduit or should some of them be separated from >the rest? Also on the strobe heads...the whelen strobes say to ground the >shielding to the power supply but in Bob's manual it says to ground the >shielding wire to the strobe heads if mounting in plastic tips. What >about it list? This is my second OBAM and the first to have more advanced >equipment and need some advice. Run them all together. Ground landing lights, nav lights and 14v power leads for strobes locally. If your strobe bases are not grounded by virtue of their location on non-conductive mounting, try leaving them floating. If you get strobe pops in received signals, consider "grounding" them to shields of leadwires that come out from the strobe supply. Bob . . . ________________________________________________________________________________
Date: Feb 09, 2004
From: Mark Steitle <msteitle(at)mail.utexas.edu>
Subject: Capacitive Fuel Gauges
Bob, I have a pair of 6 ft. Electronics International tube type capacitive fuel level probes and would like to build my own fuel level circuit(s) to use with these senders. I have a Westach 0-5v dual fuel gauge that I would also like to use. A series of articles were printed in Kitplanes magazine in mid 2000 describing how to build a CD type circuit (http://www.rst-engr.com/kitplanes/index.htm), but it used two flat plates as the sender. Do you know if the "Jim Weir" capacitive fuel level design should work with these probes. Is there an easy way to determine the capacitance of these probes? Thank you for sharing your knowledge and wisdom with the OBAM community. Mark S. ________________________________________________________________________________
From: "Alex Peterson" <alexpeterson(at)usjet.net>
Subject: battery / alternator switch
Date: Feb 09, 2004
I like the fact that I get 4 horsepower back at > cruise RPM that the Vacuum pump stole. > Four HP?!? That sounds extremely high (or maybe the air compressor marketing folks at Sears got ahold of it!). Just to put things in perspective, a 100 amp, 14 volt alternator would take just a bit more than two horsepower. In the case of the vacuum pump, where would four horsepower go? If the vacuum pump is truly taking four horses, the power has to go somewhere, either doing work (spinning gryos) or dissipating in the form of heat. The gyros' power requirements are something near zero, so everything else would be heat. Four horses are about one eighth as much heat as my home furnace puts out (about 10000btu/hr vs 80000btu/hr). I suspect fractional hp is closer. Alex Peterson Maple Grove, MN RV6-A N66AP 436 hours www.usfamily.net/web/alexpeterson ________________________________________________________________________________
From: "Dale Martin" <niceez(at)cableone.net>
Subject: Re: battery / alternator switch
Date: Feb 09, 2004
Bob asks, >One thing I found amazing is how many different places I had ground wires >terminating. I built my own ground bus only because the ones from B&C do >not appear to be mechanically attached to the brass . . . How so? Mine are riveted on and then soldered. It is the type of -push on tabs -two way, usually found on Terminal blocks (two holes instead of one) to connect female 1/4" push-on connecters. I have attached two Jpeg pictures. - Dale ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: battery / alternator switch > > > > >In the schematic's for the all electric airplane (Z-13) and the Generic > >Light Aircraft Electrical System (Z-11) both depicts a Battery / Alt switch > ># 2-10 - (2 dash 10). However, in the switches, relays and contactors pages > >it says switch 2 dash 3 is recommend for the combination Battery > >Master/alternator-field switching. > > > >Which one is correct? > > Either one works. A 2-3 combined with a PULLABLE field supply breaker > in the crowbar ov protection circuit gives the same functionality as > a 2-10. > > It's no big deal to have the alternator ON during cranking . . . so, > a 2-3 works. > > -EITHER- the mid-position on a 2-10 switch -OR- pulling the field > circuit breaker allows battery only ops for ground maintenance or turning > off a mis-behaving alternator in flight. It's not a matter of CORRECTNESS > but a matter of PREFERENCE. > > > >BTW, I have just successfully removed all wires from my 28volt IFR LEZ (with > >exception of the strobe and nav light wires in the wings) after 18 years and > >1,100 + hours of flying. Talk about scary.... This is for a much simplier > >electrical system and full panel upgrade. No more vacuum system for me and > >no more 28 to 14 inverter. Everything is 28 volt. > > Are you going to 14v or staying 28v? > > >One thing I found amazing is how many different places I had ground wires > >terminating. I built my own ground bus only because the ones from B&C do > >not appear to be mechanically attached to the brass . . . > > How so? > > >and my two boys needed > >some practice using the drill press using brass. The total price was less > >then twenty bucks with free labor. > > Also this system will only be using one alternator. Using one mag and one > >E.I is enough engine redundancy with the lone battery for essential bus. I > >believe in the good battery theory and checking it twice per year for acid > >specific gravity and over all battery condition and replacing it as needed. > > Do you have a vacuum pump pad with nothing mounted on it? > For $300 and 4 pounds you can have a SECOND engine driven > power source. > > Bob . . . > > ----------------------------------------- > ( Experience and common sense cannot be ) > ( replaced with policy and procedures. ) > ( R. L. Nuckolls III ) > ----------------------------------------- > > ________________________________________________________________________________
From: "Dale Martin" <niceez(at)cableone.net>
Subject: Re: battery / alternator switch
Date: Feb 09, 2004
This time with the pictures.......... Bob asks, >One thing I found amazing is how many different places I had ground wires >terminating. I built my own ground bus only because the ones from B&C do >not appear to be mechanically attached to the brass . . . How so? Mine are riveted on and then soldered. It is the type of -push on tabs -two way, usually found on Terminal blocks (two holes instead of one) to connect female 1/4" push-on connecters. I have attached two Jpeg pictures. - Dale ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: battery / alternator switch > > > > >In the schematic's for the all electric airplane (Z-13) and the Generic > >Light Aircraft Electrical System (Z-11) both depicts a Battery / Alt switch > ># 2-10 - (2 dash 10). However, in the switches, relays and contactors pages > >it says switch 2 dash 3 is recommend for the combination Battery > >Master/alternator-field switching. > > > >Which one is correct? > > Either one works. A 2-3 combined with a PULLABLE field supply breaker > in the crowbar ov protection circuit gives the same functionality as > a 2-10. > > It's no big deal to have the alternator ON during cranking . . . so, > a 2-3 works. > > -EITHER- the mid-position on a 2-10 switch -OR- pulling the field > circuit breaker allows battery only ops for ground maintenance or turning > off a mis-behaving alternator in flight. It's not a matter of CORRECTNESS > but a matter of PREFERENCE. > > > >BTW, I have just successfully removed all wires from my 28volt IFR LEZ (with > >exception of the strobe and nav light wires in the wings) after 18 years and > >1,100 + hours of flying. Talk about scary.... This is for a much simplier > >electrical system and full panel upgrade. No more vacuum system for me and > >no more 28 to 14 inverter. Everything is 28 volt. > > Are you going to 14v or staying 28v? > > >One thing I found amazing is how many different places I had ground wires > >terminating. I built my own ground bus only because the ones from B&C do > >not appear to be mechanically attached to the brass . . . > > How so? > > >and my two boys needed > >some practice using the drill press using brass. The total price was less > >then twenty bucks with free labor. > > Also this system will only be using one alternator. Using one mag and one > >E.I is enough engine redundancy with the lone battery for essential bus. I > >believe in the good battery theory and checking it twice per year for acid > >specific gravity and over all battery condition and replacing it as needed. > > Do you have a vacuum pump pad with nothing mounted on it? > For $300 and 4 pounds you can have a SECOND engine driven > power source. > > Bob . . . > > ----------------------------------------- > ( Experience and common sense cannot be ) > ( replaced with policy and procedures. ) > ( R. L. Nuckolls III ) > ----------------------------------------- > > ________________________________________________________________________________
From: "Dale Martin" <niceez(at)cableone.net>
Subject: Re: battery / alternator switch
Date: Feb 09, 2004
Alex, I will find out from the manufacture if I understood them incorrectly. Dale Martin Lewiston, ID LEZ-235 ----- Original Message ----- From: "Alex Peterson" <alexpeterson(at)usjet.net> Subject: RE: AeroElectric-List: battery / alternator switch > > > I like the fact that I get 4 horsepower back at > > cruise RPM that the Vacuum pump stole. > > > > Four HP?!? That sounds extremely high (or maybe the air compressor > marketing folks at Sears got ahold of it!). Just to put things in > perspective, a 100 amp, 14 volt alternator would take just a bit more > than two horsepower. In the case of the vacuum pump, where would four > horsepower go? If the vacuum pump is truly taking four horses, the > power has to go somewhere, either doing work (spinning gryos) or > dissipating in the form of heat. The gyros' power requirements are > something near zero, so everything else would be heat. Four horses are > about one eighth as much heat as my home furnace puts out (about > 10000btu/hr vs 80000btu/hr). I suspect fractional hp is closer. > > Alex Peterson > Maple Grove, MN > RV6-A N66AP 436 hours > www.usfamily.net/web/alexpeterson > > ________________________________________________________________________________
Date: Feb 09, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Wing wiring
> > >6/29/2003 > >Hello Bob Nuckolls and Bret Ferrell, I'd like to flog this horse a few more >lashes. > >1) Bob Nuckolls really says the drain wire should be attached at both ends on >a composite aircraft? But not on a metal aircraft? Why? > >2) When one receives the strobe light installation kit from Whelen the cable >already has two AMP plastic 3 wire connectors attached, one on each end. >These >connectors are the ones that plug into the mating 3 wire connectors at the >strobe light ends. After cutting the cable somewhere in the middle and >snaking >those two cut ends through the airframe to the vicinity of the strobe power >supply one installs the other two (different) appropriate 3 wire connectors >provided by Whelen and plugs the cables into the power supply. > >3) The installation instructions say that the drain wire should be connected >to the housing / mounting of the power supply. Easy enough to do by leaving >the drain wire longer when you cut the cable, strip it, and install the 3 >wire >connectors that plug into the power supply. > >4) But out at the strobe light end of the cable where the Whelen installed >connectors are, Whelen has left no access to the drain wire. I suppose one >could >cut back the plastic covering, remove the aluminum shield, attach a short >wire to the now exposed drain wire, and then attach that short wire to >some metal >part of the strobe light housing, but I find this action both puzzling and >unnecessary. > >5) Whelen has thousands of these units in service throughout the skies >mounted on both metal surfaces and composite wing tips. I am unaware of >any need to >go through the additonal effort of connecting the drain wire to the metal >light housing out at the strobe light end. Can anyone show me different? My friend, you're stirring requirements into the same pot with practice and recommendations based on physics of the best we know how to do. You are correct that hundreds of thousands of airplanes have been wired per manufacturer's instructions and are "successfully" navigating the skies. I can also tell you that when we installed strobes on the Cessnas in the 60's (per manufacturer's instructions) our pilots complained of new noises in the systems. We went to a lot of effort to mitigate them. I use the term "mitigate" because we never did eliminate the noises. However, I recall that adding shielding to the clear dome over the strobes and grounding the base of the strobes to the shield produced noticeable reduction in noise. 40 years later, the noises that our pilots complained about then are now considered commonplace and nobody bothers to honk about them. I don't recall now if Cessna decided whether or not to pursue noise reduction to levels over and above that which was supplied or recommended by Whelen. By the same token, there are a hundred thousand plus airplanes that don't used single point grounds, still bring b-lead right to the bus, etc. etc. (although I understand current production Cessnas now have single point grounds). The task here is to do a best practical anticipation of future "problems" while elevating our art with sound supporting science. There are no requirements . . . if the way a cookie cutter spam-can performs and it's the technology a builder embraces, then many things discussed here on the list will not be of interest. Suggestions should not be mistaken for requirements. The vast majority of OBAM aircraft ARE being assembled and wired in the great tradition of Cessna, Piper, Beech, et. als. and most of those airplanes will be pronounced "satisfactory" by their owners . . . many because they don't know what their options are for vaulting over higher bars with ease. My personal goal is to improve the ODDS on "satisfactory" completion of the maximum number of airplanes while improving on system reliability. We know that certain techniques have value. Sometimes it's a very tiny benefit and perhaps insignificant in the final configuration of completed project. But when someone comes up on the list with a noise problem, it's very helpful to know if they've implemented all the techniques we've identified as easy and useful. That clears the table of the ordinary problems and lets us concentrate on new ones. If he says, "Naw, wired 'er up per Van's diagrams and the kit he supplied," the dragons to be eliminated are more numerous to identify and potentially more laborious to fix. Bob . . . ________________________________________________________________________________
From: "buck" <buckaroo_banzai@the-pentagon.com>
Subject: Re: For Bob, Comment?
Date: Feb 09, 2004
Quite often, the installers of a STC system try to take advantage of what's already in the aircraft without fully realizing that they may be circumventing the intent of the aircraft manufacturer. It's amazing that the FAA and JAA are willing to grant the STC at all! ---------------------------------------------- Original Message From: "ivorphillips"<ivor(at)ivorphillips.flyer.co.uk> Subject: Re: AeroElectric-List: For Bob, Comment? Date: Mon, 9 Feb 2004 15:41:18 -0000 > >> There is an upcoming program on Public Broadcasting: NOVA: The Deadly >It deals with an inflight fire caused by electrical arcing. >> >Have seen this program a couple of weeks ago, It make you wonder how a >commercial aircraft can have its wiring set up in such away that the pilots >were unable to isolate the entertainment system from the main cockpit Bus! >No breakers tripped to alleviate the problem, just smoke from behind >panelling, > >I find it hard to believe that circuits are shared without proper regards >too overload wire protection, Its criminal that so many folk lost their >lives due to a preventable wiring short circuit. > >Ivor Phillips >Europa xs > > http://www.MyOwnEmail.com Looking for friendships,romance and more? http://www.MyOwnFriends.com ________________________________________________________________________________
From: TSaccio(at)aol.com
Date: Feb 09, 2004
Subject: Re: ectric-List:Accuator switch
I'm trying to wire two accuators that let my canopy go up and down. Can anyone tell me what kind of switch I need to do this and how it is wired? Thanks in advance. Tom Saccio ________________________________________________________________________________
From: "Dale Martin" <niceez(at)cableone.net>
Subject: Re: ectric-List:Accuator switch
Date: Feb 09, 2004
Stepper motors and a control card otta' do it just fine...... ----- Original Message ----- From: <TSaccio(at)aol.com> Subject: Re: AeroElectric-List:Accuator switch > > I'm trying to wire two accuators that let my canopy go up and down. Can > anyone tell me what kind of switch I need to do this and how it is wired? Thanks in > advance. > > Tom Saccio > > ________________________________________________________________________________
Date: Feb 09, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: battery / alternator switch
> >Bob asks, > > >One thing I found amazing is how many different places I had ground wires > >terminating. I built my own ground bus only because the ones from B&C do > >not appear to be mechanically attached to the brass . . . > > How so? > >Mine are riveted on and then soldered. It is the type of -push on tabs -two >way, usually found on Terminal blocks (two holes instead of one) to connect >female 1/4" push-on connecters. > >I have attached two Jpeg pictures. Attachments don't get forwarded through the list but that's okay. Rivets are fine too but let's take care lest folks begin to worry about solder as a structural material. With a tensile strength on the order of 3Kpsi or better, likelihood of anyone pulling the fast-on tabs from their B&C fabricated ground bus is very remote. Bob . . . ________________________________________________________________________________
Date: Feb 09, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: battery / alternator switch
> > > >I like the fact that I get 4 horsepower back at > > cruise RPM that the Vacuum pump stole. > > > >Four HP?!? That sounds extremely high (or maybe the air compressor >marketing folks at Sears got ahold of it!). Just to put things in >perspective, a 100 amp, 14 volt alternator would take just a bit more >than two horsepower. In the case of the vacuum pump, where would four >horsepower go? If the vacuum pump is truly taking four horses, the >power has to go somewhere, either doing work (spinning gryos) or >dissipating in the form of heat. The gyros' power requirements are >something near zero, so everything else would be heat. Four horses are >about one eighth as much heat as my home furnace puts out (about >10000btu/hr vs 80000btu/hr). I suspect fractional hp is closer. I think you're right. Wonder if the decimal place didn't get moved. 0.4 Hp sounds just about right! Bob . . . ________________________________________________________________________________
From: "Dale Martin" <niceez(at)cableone.net>
Subject: Re: battery / alternator switch
Date: Feb 09, 2004
Seems like Wayne Blackler has one with the tabs coming off in his tool box. Each to his own I guess. Dale Martin Lewiston, ID LEZ-235 ----- Original Message ----- From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> Subject: Re: AeroElectric-List: battery / alternator switch > > > > >Bob asks, > > > > >One thing I found amazing is how many different places I had ground wires > > >terminating. I built my own ground bus only because the ones from B&C do > > >not appear to be mechanically attached to the brass . . . > > > > How so? > > > >Mine are riveted on and then soldered. It is the type of -push on tabs -two > >way, usually found on Terminal blocks (two holes instead of one) to connect > >female 1/4" push-on connecters. > > > >I have attached two Jpeg pictures. > > Attachments don't get forwarded through the list > but that's okay. Rivets are fine too but let's take > care lest folks begin to worry about solder as a structural > material. With a tensile strength on the order of 3Kpsi or > better, likelihood of anyone pulling the fast-on tabs from > their B&C fabricated ground bus is very remote. > > Bob . . . > > ________________________________________________________________________________
Date: Feb 09, 2004
From: Jerzy Krasinski <krasinski(at)direcway.com>
Subject: Re: Capacitive Fuel Gauges
I messed around with Jim Weir circuit, but finally I gave up and I made it using a circuit commonly used as a converter changing volmeter into capacitance meter. Such a circuit is much simpler, it uses a popular double timer (556?) and an op amp. Capacitance of my 1 yard long probes made of 1/2 and 1/4 tubes is around 114 pF, which I measured by a digital multimeter as well as by substitution of the probe by a capacitor. Unfortunately, making such a system requires some tinkering and adjusting the circuit to get proper readings. You must also have some basic electronic instruments. Jerzy Mark Steitle wrote: > >Bob, >I have a pair of 6 ft. Electronics International tube type capacitive fuel >level probes and would like to build my own fuel level circuit(s) to use >with these senders. I have a Westach 0-5v dual fuel gauge that I would >also like to use. A series of articles were printed in Kitplanes magazine >in mid 2000 describing how to build a CD type circuit >(http://www.rst-engr.com/kitplanes/index.htm), but it used two flat plates >as the sender. Do you know if the "Jim Weir" capacitive fuel level design >should work with these probes. Is there an easy way to determine the >capacitance of these probes? > >Thank you for sharing your knowledge and wisdom with the OBAM community. >Mark S. > > > > ________________________________________________________________________________
Date: Feb 09, 2004
From: f1rocket(at)telus.net
Subject: Hidden antenna
Has anyone out there uses the "Advanced Aircraft Electronics High Gail Aircraft Antenna Systems" available at AS$? Esspecially the transponder antenna looks interesting. Regards, Jeff ________________________________________________________________________________
From: "hollandm" <hollandm(at)pacbell.net>
Subject: Compass shielding
Date: Feb 09, 2004
I'm getting interference between an electric turn coordinator and a compass (about 2 degrees). Before I start moving things around I was wondering if it would be possible to shield the compass by surrounding it with some copper screening or the like, sort of mu-metal chamber approach. Has anyone tried this and if so did it work? Thanks ________________________________________________________________________________
Date: Feb 10, 2004
From: Kevin Horton <khorton01(at)rogers.com>
Subject: LED light bar annunciator panel?
I'm seriously considering manufacturing a small annunciator panel from Stanley LED light bars. These are the ones with part numbers like MU04-2101 sold by Digikey, etc. I am wondering what options I would have to put legends on the face of the light bars. What looks good and lasts a long time? I am also looking for ideas on how to package the resistors, etc needed to limit the current. Does anyone have any pictures they could point me too? Thanks, -- Kevin Horton RV-8 (finishing kit) Ottawa, Canada http://go.phpwebhosting.com/~khorton/rv8/ ________________________________________________________________________________
From: BFV25(at)aol.com
Date: Feb 10, 2004
Subject: Re: AeroElectric-List Digest: 29 Msgs - 02/09/04
Please remove me for your mail list bfv25(at)aol.com ________________________________________________________________________________
From: "Bruce Gray" <Bruce(at)glasair.org>
Subject: Compass shielding
Date: Feb 10, 2004
If you shield the compass it will no longer be a compass. It has to be able to sense the magnetic fields. Bruce www.glasair.org -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of hollandm Subject: AeroElectric-List: Compass shielding I'm getting interference between an electric turn coordinator and a compass (about 2 degrees). Before I start moving things around I was wondering if it would be possible to shield the compass by surrounding it with some copper screening or the like, sort of mu-metal chamber approach. Has anyone tried this and if so did it work? Thanks == == == == ________________________________________________________________________________
Date: Feb 10, 2004
From: Mark Steitle <msteitle(at)mail.utexas.edu>
Subject: Re: Capacitive Fuel Gauges
> > >I messed around with Jim Weir circuit, but finally I gave up and I made >it using a circuit commonly used as a converter changing volmeter into >capacitance meter. Such a circuit is much simpler, it uses a popular >double timer (556?) and an op amp. Capacitance of my 1 yard long probes >made of 1/2 and 1/4 tubes is around 114 pF, which I measured by a >digital multimeter as well as by substitution of the probe by a capacitor. Jerzy, So I would guess that my 6 ft. fuel probe, being twice the length of your 3 ft probe, would have roughly twice the capacitance? Which Jim Weir circuit did you build, early or late version? A friend built an early version and got it working, but we had mixed results when we substituted my probe for his aluminum plate capacitor. As a result, I thought I might try building one of the Rev. 2 circuits. I would have to search around for someone with a dual-trace scope to help me adjust/tune the circuit. Nice thing about the Rev. 2 design is the integrated low fuel warning light & buzzer. Do you have any pictures of your design? Or, would you be willing to share the schematic? Thanks, Mark S. ________________________________________________________________________________
Date: Feb 10, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Compass shielding
> >If you shield the compass it will no longer be a compass. It has to be >able to sense the magnetic fields. > >Bruce >www.glasair.org > > >-----Original Message----- >From: owner-aeroelectric-list-server(at)matronics.com >[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of >hollandm >To: aeroelectric-list(at)matronics.com >Subject: AeroElectric-List: Compass shielding > > > > >I'm getting interference between an electric turn coordinator and a >compass (about 2 degrees). Before I start moving things around I was >wondering if it would be possible to shield the compass by surrounding >it with some copper screening or the like, sort of mu-metal chamber >approach. > >Has anyone tried this and if so did it work? > >Thanks Don't shield the victim, shield the antagonist. Cut a strip of galvanized flashing metal from the lumber yard so as to wrap around the t/c about 3 times. Secure in place with tye-wraps, aluminum tape, string, etc. I believe this has worked for a number of builders. Let us know how it does for you. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
From: "Gary Casey" <glcasey(at)adelphia.net>
Subject: RE: Load dump protection
Date: Feb 10, 2004
<> Load dump protection in autos is still a real thing. There is a "switch" between the alternator and the battery and it is the battery terminal itself. The worst case, that is mostly worried about by boat manufacturers, is a loose connection on the battery terminal that vibrates, repeatedly opening and closing. The electronics builders for boats find that it has not been "solved" as you imply, but is almost a normal situation. The usual scenario is that the boater stores his boat over the winter, then finds the battery is dead. He removes the battery and charges it for 10 minutes (the family is waiting) and then puts it in the boat and just pushes the battery cable on. The loose cable vibrates, the battery is accepting maximum charge and the voltage transients are incredible - and repeated many times a second. Also, the battery doesn't have to be disconnected to have a load dump. Any time a large load is shut off the alternator has to instantly reduce its output, which it can't do because of the inductance of the field windings. Of course, having the battery there tames the load dump to a very manageable amplitude. Gary Casey ________________________________________________________________________________
From: "Dale Martin" <niceez(at)cableone.net>
Subject: Re: Compass shielding
Date: Feb 10, 2004
mount it 8 to 10 inches from any electrical current. Dale Martin Lewiston, ID LEZ-235 ----- Original Message ----- From: "Bruce Gray" <Bruce(at)glasair.org> Subject: RE: AeroElectric-List: Compass shielding > > If you shield the compass it will no longer be a compass. It has to be > able to sense the magnetic fields. > > Bruce > www.glasair.org > > > -----Original Message----- > From: owner-aeroelectric-list-server(at)matronics.com > [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of > hollandm > To: aeroelectric-list(at)matronics.com > Subject: AeroElectric-List: Compass shielding > > > > > I'm getting interference between an electric turn coordinator and a > compass (about 2 degrees). Before I start moving things around I was > wondering if it would be possible to shield the compass by surrounding > it with some copper screening or the like, sort of mu-metal chamber > approach. > > Has anyone tried this and if so did it work? > > Thanks > > > == > == > == > == > > ________________________________________________________________________________
Date: Feb 10, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Capacitive Fuel Gauges
> > >Bob, >I have a pair of 6 ft. Electronics International tube type capacitive fuel >level probes and would like to build my own fuel level circuit(s) to use >with these senders. I have a Westach 0-5v dual fuel gauge that I would >also like to use. A series of articles were printed in Kitplanes magazine >in mid 2000 describing how to build a CD type circuit >(http://www.rst-engr.com/kitplanes/index.htm), but it used two flat plates >as the sender. Do you know if the "Jim Weir" capacitive fuel level design >should work with these probes. Is there an easy way to determine the >capacitance of these probes? > >Thank you for sharing your knowledge and wisdom with the OBAM community. >Mark S. The length of your probe is only part of the equation. Jim's circuitry is designed to work with a specific change in capacitance from some total to indicate empty to full. E.g., the probe may have a range of 150 uF empty to 1000 pF full. You might have a coax connecing the probe to the electronics that adds another 100 pF. So, the electronics needs adjusting such that empty is 250 pF and full is 1100 pF. So, if you have a probe you like and a piece of shielded wire picked to connect probe to electronics, the task is to mate the electronics to the probe/cable combination. Jim's schematic includes empty and full adjust pots. What you need to know is how close the probe you have comes to the one Jim describes. His circuit CAN be made to work with about ANY probe. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Feb 10, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> 02/09/04
Subject: Re: AeroElectric-List Digest: 29 Msgs -
02/09/04 02/09/04 > >Please remove me for your mail list >bfv25(at)aol.com You need to go to the UN/SUBSCRIBE address cited below where you can do it yourself. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Feb 10, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: battery / alternator switch
> >Seems like Wayne Blackler has one with the tabs coming off in his tool box. >Each to his own I guess. > >Dale Martin >Lewiston, ID >LEZ-235 Has he done anything about it? If B&C doesn't want it back, I'd sure like to see it. Bob . . . >----- Original Message ----- >From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> >To: >Subject: Re: AeroElectric-List: battery / alternator switch > > > > > > > > > > > >Bob asks, > > > > > > >One thing I found amazing is how many different places I had ground >wires > > > >terminating. I built my own ground bus only because the ones from B&C >do > > > >not appear to be mechanically attached to the brass . . . > > > > > > How so? > > > > > >Mine are riveted on and then soldered. It is the type of -push on >tabs -two > > >way, usually found on Terminal blocks (two holes instead of one) to >connect > > >female 1/4" push-on connecters. > > > > > >I have attached two Jpeg pictures. > > > > Attachments don't get forwarded through the list > > but that's okay. Rivets are fine too but let's take > > care lest folks begin to worry about solder as a structural > > material. With a tensile strength on the order of 3Kpsi or > > better, likelihood of anyone pulling the fast-on tabs from > > their B&C fabricated ground bus is very remote. > > > > Bob . . . > > > > > > Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Feb 10, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: For Bob, Comment?
><buckaroo_banzai@the-pentagon.com> > >Quite often, the installers of a STC system try to take advantage of what's >already in the aircraft without fully realizing that they may be >circumventing the intent of the aircraft manufacturer. It's amazing that >the FAA and JAA are willing to grant the STC at all! STC's generally cannot be grand-fathered to other airframes. STC is exactly what the acronym implies . . . SUPPLEMENT to a TYPE CERTIFICATE. These are not used as plug-n-play across a range of aircraft. STC is EXACTLY what those-who-know-more-about-airplanes-than- we-do like. Treat every installation like it's never been done before and test the hell out of it. This keeps those who don't understand what's happening from having to think or learn anything. It makes sure that some wheels get invented over and over again. The STC route is relatively low risk but also expensive because common sense approaches are neither encouraged or allowed. Everyone is expected to read and respond to a rule book. Whether or not he/she understands the system to which the rules are applied no longer matters. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________________________________________________________
Date: Feb 10, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: battery / alternator switch
> >Bob says, > > Do you have a vacuum pump pad with nothing mounted on it? > > For $300 and 4 pounds you can have a SECOND engine driven > > power source. > > > > Bob . . . > >I think you mean a Third source. (Battery =1, Alt =2, Second Alt = 3) >I like the fact that I get 4 horsepower back at cruise RPM that the Vacuum >pump stole. Yes, third system source but only the second engine-driven power source. > > Are you going to 14v or staying 28v? > >I will keep 28 v due to the wire size I use are smaller and paid for! And >have a second full size Alternator on the shelf. >But to your credit I did consider it but..... then would have to change the >starter, Alt, Nav-Com 1, landing light, strobe power unit and all the bulbs >not to mention the LR3. Your talking over $2000 bucks and accepting peanuts >for some of the equipment I have now. Understand. >BTW, I have always started the engine with the Alt off. Doesn't hurt, but with a well maintained RG battery, probably has no benefit other than to delay onset of alternator activity. One might argue that the pilot is watching for effects of the current action . . . getting the engine started usually concentrates on things like oil pressure. If the alternator comes up immediately in a bad mood, it's not likely to be observed as soon as if the pilot gets the engine started first and then turns on the alternator while watching instrumentation unique to that activity. >One thing I think is an error IMHO is not using separate Ignition Switches >either Guarded or Locking toggle switch for magneto's and especially the >older LSE electronic ignitions. When the LSE E.I. are turned on they fire >all the plugs at once - Yikes ! May not be a good idea to do this at any >RPM. If you were to bump on off in-flight and turn it back on... and it >fired say 65 BTDC..... That would really mess things up. Klaus warned me >about it. I've heard a lot of concerns over the years about "accidental" switch operation. It's an easy thing to hypothesize but equally easy to arrange the panel to avoid it too. Hmmm . . . at ANY RPM? What happens when you do ignition system checks by turning them off and on one at a time to observe operation of each system independently? >On the alternator thread ....... > >If the C/B on the LR3 field wire were pulled (engine running) is the Alt >able to still send out power just not regulated? If it does, that is not >good. I was taught without the field there is no power. No, with an externally regulated alternator, pulling the field supply breaker shuts the system down completely. This has always been the architecture of choice . . . but we'll soon figure out how to apply internally regulated alternators with equal degree of comfort. Bob . . . ________________________________________________________________________________
Date: Feb 10, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: Battery Charger
> >I am looking at buying a float charger for my 24volt spam can. This spam can >has an always hot battery bus with the the ships clock on it. I was >concerned about the following marketing statement as to whether it might >harm the clock. Anyone care to comment? > >Thanks, >Ned > > "High-frequency pulse breaks down sulphated crystals that prevent batteries >from holding a full charge." This is a battery maintainer combined with a "de-sulfater". It should be just fine. It won't hurt your clock or anything else in the airplane. Bob . . . ________________________________________________________________________________
Date: Feb 10, 2004
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: 11153 Santerre
>Below is the result of your inquiry. It was submitted by >Kim Santerre (ksanterre(at)aol.com) on Monday, February 9, 2004 at 19:39:38 > >Monday, February 9, 2004 > >Kim Santerre > >, >Email: ksanterre(at)aol.com >Comments/Questions: Hi Bob: > >One of our Light Plane Maintenance Readers wants to know why starter and >other high current solenoids seem to so badly designed. He said upon >dissassembly it is obvious that only small points of the contact surface >repeatedly contact and arc and subsequently have earlier failures than >they should. Are there any sources of really good quality stuff. He has a >Lancair. Thanks. Kim Santerre The writer doesn't understand the physics of high current, intermittent duty contacts. Virtually EVERY automotive starter contactor uses the low area very high pressure philosophy for making and breaking current to the starter. Now, if he's seeing poor contactor life, it may have to do with issues outside the design of the contacts themselves. This is very mature technology with thousands of this style contactor flying in airplanes and millions in ground based vehicles. His problems may have more to do with WHO builds the contactor than with the basic science that's supposed to make it work. I will invite you to join us on the AeroElectric List to continue this and similar discussions. It's useful to share the information with as many folks as possible. A further benefit can be realized with membership on the list. There are lots of technically capable folks on the list who can offer suggestions too. You can join at . . . http://www.matronics.com/subscribe/ Thanks! Bob . . . -------------------------------------------- ( Knowing about a thing is different than ) ( understanding it. One can know a lot ) ( and still understand nothing. ) ( C.F. Kettering ) -------------------------------------------- ________________________________________________________________________________
Date: Feb 10, 2004
From: Dave Morris <dave(at)davemorris.com>
Subject: Re: LED light bar annunciator panel?
You can have an entire annunciator panel built for you by Aircraft Simulators.com Take a look at this: http://www.aircraftsimulators.com/F16caution.html They can furnish just the panel or also the LEDs and wiring.


January 28, 2004 - February 10, 2004

AeroElectric-Archive.digest.vol-cw