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AeroElectric-Archive.digest.vol-aq
February 27, 2002 - March 13, 2002

>BTW, yesterday I had a long talk with my local FSDO >airworthiness inspector about a simple and safe >modification I want to make to a customer's Mooney... >sigh. As they say, "Arguing with an inspector is like >wrestling with a pig in the mud; after awhile you >realize they both enjoy it." >My next airplane will be a homebuilt. My opening comments at weekend seminars include the statement that the amateur built aircraft industry is putting out the finest airplanes to have ever flown. Of course, I have to follow up with the reasoning that when we find that something needs to be changed either to fix it or to make it perform better, it can happen today without waiting on the blessings of anybody . . . If you want to hose something up, get government to regulate/manage it. Bob . . . ________________________________________________________________________________
Date: Feb 27, 2002
From: William Mills <courierboy(at)earthlink.net>
Subject: Re: Microair radio & xpdr amp requirements
> > I'll be > offering a kit of transponder, prewired harness and > ACK encoder for a package price. > > Bob . . . Yes, please do! Bill Mills ________________________________________________________________________________
Date: Feb 27, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Wig-Wag - FOLLOW-UP
> >Follow-up, follow-up >Bob, > >In going through all the switch combinations, I discovered one anomaly >that I'd rather avoid. It is an unlikely combination but still possible. >Here is the logic table: > >Switches Lights >Taxi Landing Taxi Landing >Down Down Off Off >Down Mid Wig Wag >Down UP Off On >Mid Down Off Off >Mid Mid Wig Wag >Mid Up Off On >Up Down On Off >Up Mid On off - relay rapid chatter >Up Up On On > >It is the rapid chatter (much faster than wig-wag rate) of relay that >concerns me. The switch positions are not normal but are possible. >Knowing the circuitry of the controller, is there some alternative >wiring I might try? Try moving the brown and yellow wires over to join the red . . . i.e. all three wires on one connection. Bob . . . ________________________________________________________________________________
Date: Feb 27, 2002
From: Richard Dudley <rhdudley(at)att.net>
Subject: Re: Wig-Wag - FOLLOW-UP
Bob, Earlier, I removed the yellow-brown combination from the switch and it had no effect. I joined the yellow-brow combination with the red wire and the logic table remains the same. RHD Robert L. Nuckolls, III wrote: > > > > > >Follow-up, follow-up > >Bob, > > > >In going through all the switch combinations, I discovered one anomaly > >that I'd rather avoid. It is an unlikely combination but still possible. > >Here is the logic table: > > > >Switches Lights > >Taxi Landing Taxi Landing > >Down Down Off Off > >Down Mid Wig Wag > >Down UP Off On > >Mid Down Off Off > >Mid Mid Wig Wag > >Mid Up Off On > >Up Down On Off > >Up Mid On off - relay rapid chatter > >Up Up On On > > > >It is the rapid chatter (much faster than wig-wag rate) of relay that > >concerns me. The switch positions are not normal but are possible. > >Knowing the circuitry of the controller, is there some alternative > >wiring I might try? > > Try moving the brown and yellow wires over to join > the red . . . i.e. all three wires on one connection. > > Bob . . . > ________________________________________________________________________________
Date: Feb 27, 2002
From: Michel Therrien <mtherr(at)yahoo.com>
Subject: ElectrONic AH and DG?
Hello group, I would like to have gyros or equivalent in my plane, but I have not found simple electronic gyros yet. At one end of the scale, I found a device which connects to a PDA so you see attitude information on the PDA's screen. At the other end, I found integrated engine instruments, attitude, altitude, airspeed, temperature, direction, gps and whatever you can imagine. Will there be any device available to simply replace mechanic AH and DG in a unit of similar size? Thanks for your insight. ===== ---------------------------- Michel Therrien CH601-HD http://pages.infinit.net/mthobby http://mthobby.pcperfect.com/ch601 http://greetings.yahoo.com ________________________________________________________________________________
From: "Craig Snively" <craigsn(at)hotmail.com>
Subject: ElectrONic AH and DG?
Date: Feb 27, 2002
There are a couple of possibilities out there, Blue Mountain Avionics makes one called the EFIS/Lite - (http://www.bluemountainavionics.com/efislite/about.html) and the Dynon EFIS-10. at http://www.dynondevelopment.com/ Bothof them have some features you describe, although they are not simple electronic gyros. And they are pricey. -----Original Message----- From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Michel Therrien Subject: AeroElectric-List: ElectrONic AH and DG? Hello group, I would like to have gyros or equivalent in my plane, but I have not found simple electronic gyros yet. At one end of the scale, I found a device which connects to a PDA so you see attitude information on the PDA's screen. At the other end, I found integrated engine instruments, attitude, altitude, airspeed, temperature, direction, gps and whatever you can imagine. Will there be any device available to simply replace mechanic AH and DG in a unit of similar size? Thanks for your insight. ===== ---------------------------- Michel Therrien CH601-HD http://pages.infinit.net/mthobby http://mthobby.pcperfect.com/ch601 http://greetings.yahoo.com = = = http://www.matronics.com/browselist/aeroelectric-list = ________________________________________________________________________________
From: "Ed Perry" <eperry(at)san.rr.com>
Subject: Constant discharge on the battery
Date: Feb 27, 2002
Hi Everyone, I am currently flying a SuperCub and have been having trouble with the charging system. The AMP meter shows a constant discharge and the battery keeps going dead. We have replaced the Generator, Battery, generator circuit breaker, and voltage regulator with no success. What am I missing here? The AMPS gauge is a negative - zero - positive readout. There is no Volts gauge. Whatelse should I be looking at? Thank You, Ed Perry eperry(at)san.rr.com ________________________________________________________________________________
Date: Feb 27, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: ElectrONic AH and DG?
> > >Will there be any device available to simply replace >mechanic AH and DG in a unit of similar size? > >Thanks for your insight. yes . . . but probably not this year . . . but certainly within say 5 years. the technology is here. it just needs to be applied in enough OTHER consumer products to drive the prices down to levels practical for our use. I've got a 3-axis laser gyro on my bench right now that's going to replace iron gyros in several of our targets at RAC. We've built our last iron gyro stabilized product. . . . and it's only about $4,000 per axis. It was $10,000 per axis the last time we considered it for a target upgrade . . . about 6 years ago. Bob . . . ________________________________________________________________________________
From: "John Warren" <jwdub(at)teleport.com>
Subject: Re: ElectrONic AH and DG?
Date: Feb 27, 2002
It's probably more than what you're looking for but take a look at www.dynondevelopment.com Their product, soon to be released includes about 10 things in an EFIS display. ----- Original Message ----- From: "Michel Therrien" <mtherr(at)yahoo.com> Subject: AeroElectric-List: ElectrONic AH and DG? > > Hello group, > > I would like to have gyros or equivalent in my plane, > but I have not found simple electronic gyros yet. > > At one end of the scale, I found a device which > connects to a PDA so you see attitude information on > the PDA's screen. > > At the other end, I found integrated engine > instruments, attitude, altitude, airspeed, > temperature, direction, gps and whatever you can > imagine. > > Will there be any device available to simply replace > mechanic AH and DG in a unit of similar size? > > Thanks for your insight. > > > ===== > ---------------------------- > Michel Therrien CH601-HD > http://pages.infinit.net/mthobby > http://mthobby.pcperfect.com/ch601 > > http://greetings.yahoo.com > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
Date: Feb 27, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: speed reduction
>Bob, Do you have a schematic for a speed reduction device for the trim >servos that I can build or is it something that I have to buy such as >the Governor Mk III is a speed reduction and switch multiplexer for the >MAC Trim series of aircraft trim servos from Matronics? You can use an LM317 regulator from Radio Shack to build an adjustable power supply that will provide the necessary, lower voltage for slower operation. Are you talking about MAC linear actuators? These only draw a few hundred milliamps and can be easily controlled by the smallest plastic device (LM317T). You can find data on the device along with hookup info at: http://www.national.com/ds/LM/LM117.pdf Matt's product is another alternative. Also, in a few weeks, the B&C catalog on our website will offer the full range of dimmers as two channel, adjustable power conditioners. You can see a prototype of the 1.5A controller at: http://209.134.106.21/temp/apc15-14a.jpg and http://209.134.106.21/temp/apc15-14b.jpg A closeup view of the board is found at http://209.134.106.21/temp/apc15-14c.jpg In the closeup view you can see the two potentiometers that set output voltage. These can be used as a two-channel controller where one might need hi and low speed trim speed adjustment. It can also be used as a single channel device to provide clean, regulated power to accessories that require some voltage less than 14v to operate. These will probably sell for the same price as their dimmer counterparts . . . the two surface mounted potentiometers on the power conditioner cost about the same as the panel mounted potentiometer and knob for the dimmer. When the products are being offered for sale, you'll be able to download a copy of the installation instructions which will show how to hook it up for the various tasks. Bob . . . ________________________________________________________________________________
Date: Feb 27, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Wig-Wag - FOLLOW-UP
> >Bob, >Earlier, I removed the yellow-brown combination from the switch and it >had no effect. >I joined the yellow-brow combination with the red wire and the logic >table remains the same. When I developed the wiring diagrams posted on my website, I had examples of the Galls products to test on the bench and make sure that it would work as advertised. If you'll send me your flasher, I'll figure out what needs to be done to make it work in your airplane. Ship it to 6936 Bainbridge Road, Wichita, KS 67226-1008 Bob . . . ________________________________________________________________________________
Date: Feb 27, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Microair Xpndr
> >Somebody at Becker told me they got approval for their >ATC-4401 just last week. As it was the case for the >Microair unit, approval for the Becker unit was >delayed many months. Becker mentioned they're going >to ship transponders within 3 weeks... of course, I >will decide if I believe that in 4 weeks :-) > >Perhaps something happened at the FAA so they have >time to put stamps on documents...? I think the FAA is all through torturing Microair on this product . . . I think it's the FCC taking their turn. Bob . . . ________________________________________________________________________________
Date: Feb 27, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Fuses/CB's
> > >Hi Bob, > > Another question for you...on fig. Z-14 on the main power bus, you show >mostly fuses and then there's a 5A CB for the ALT FIELD. Why the CB instead >of a fuse? Sounds like it makes sense, but I'm curious to hear the real >rationale! The alternator system shuts down by means of a crowbar ov module that will deliberately short the field supply line to ground - expecting the upstream fault protection to open up and remove power from the alternator. Don't want to do this with fuses. Crowbar OV modules can be nuisance tripped so this is the one place where I use a circuit breaker. > Also you have a CB for the hyd pump...This seems to make sense >too, since there isn't actually an on-off switch for the pump and it would >be nice to have "override" control. Is this the rationale for the hyd pump >CB? Are there any other systems that you would think would be nice to have >this control over, ie use a CB over a fuse even tough you are going >primarily with fuses? I drew that before B&C was handling the ANL limiters. I wasn't intending that to be any kind of controller . . . the pump motor has a high inrush and the JJS/JJN type fuses were inappropriate to protecting this kind of feeder. The ANLs are just the ticket. Even if you use a breaker for the pump, I wouldn't put it on the panel . . . one of the goals of clean system design is to keep those kind of current carrying conductors away from the panel. I did have one Glasair builder mount his pump circuit breaker low on the right side kick panel so he could reach it if he stuck a contactor. This should be a rare event and if it happens, you can treat it just like an alternator out event. Kill the main bus to shut off the pump. Continue to intended destination and turn the main bus on long enough to cycle the gear . . . or leave it off and use the primary gear extension system (the manual one that ALWAYS works) to lower the gear. >Also how exactly do you wire the CB off the fuse block? Your diagram only >shows the CB connected to the fuse block, ie no connecting wire from the >fuse block to the CB??? Opps . . . that should be drawn like the alternator field breaker in figure Z-11 . . . a fusible link at the fuseblock extends the bus up to a breaker mounted beside the DC POWER MASTER switch. Need to fix that! Bob . . . ________________________________________________________________________________
Date: Feb 27, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Constant discharge on the battery
> >Hi Everyone, > >I am currently flying a SuperCub and have been having trouble with the >charging system. The AMP meter shows a constant discharge and the >battery keeps going dead. We have replaced the Generator, Battery, >generator circuit breaker, and voltage regulator with no success. What >am I missing here? The AMPS gauge is a negative - zero - positive >readout. There is no Volts gauge. Whatelse should I be looking at? > >Thank You, >Ed Perry >eperry(at)san.rr.com It's always better to get out the voltmeter and find out what's broke before pulling it off airplane. If all the parts you put in are known good parts then there must be a wiring problem or a failure in other parts like the generator switch. Is the voltage regulator getting power through the breaker to the B or BAT terminal? What is the voltage on the generator's field terminal when the switches are all on with the engine running vis-a-vis engine stopped? Do you have a diagram as to how the airplane is wired? Have you considered putting a B&C L-40 alternator on to replace the generator? This has been done perhaps a hundred times on Super Cubs with one time field approval. Do you have a friendly local FSDO that would help you with paperwork? Bob . . . ________________________________________________________________________________
From: "Paul Besing" <azpilot(at)extremezone.com>
Subject: Re: Constant discharge on the battery
Date: Feb 27, 2002
Wire guage? If you wire guage is too light, it won't carry the current through. Have you chased the voltage? See where it is showing live voltage and how much? If you put a volt meter on your battery while the engine is running, you should get about 14 volts or so. Paul Besing RV-6A N197AB Arizona http://www.lacodeworks.com/besing First Flight 22 July 01 Kitlog Pro Builder's Log Software http://www.kitlog.com ----- Original Message ----- From: "Ed Perry" <eperry(at)san.rr.com> Subject: AeroElectric-List: Constant discharge on the battery > > Hi Everyone, > > I am currently flying a SuperCub and have been having trouble with the > charging system. The AMP meter shows a constant discharge and the > battery keeps going dead. We have replaced the Generator, Battery, > generator circuit breaker, and voltage regulator with no success. What > am I missing here? The AMPS gauge is a negative - zero - positive > readout. There is no Volts gauge. Whatelse should I be looking at? > > Thank You, > Ed Perry > eperry(at)san.rr.com > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Richard Sipp" <rsipp(at)earthlink.net>
Subject: Re: ElectrONic AH and DG?
Date: Feb 27, 2002
> Hello group, > > I would like to have gyros or equivalent in my plane, > but I have not found simple electronic gyros yet. > > At one end of the scale, I found a device which > connects to a PDA so you see attitude information on > the PDA's screen. > In addition to those already mentioned, Sigma Tek, at last year's Oshkosh (oops Air Venture), was showing prototypes for direct electronic replacements of the attitude and directional gyros. No information on price or availability was provided. Dick Sipp N250DS ________________________________________________________________________________
Date: Feb 27, 2002
Subject: Electrical System Instrumentation
From: Don Boardman <dboardm3(at)twcny.rr.com>
Hi Bob, A little background: I have had your book and have been reading the list for several months now. I have been through the book once and back to sections a few times. I absorb more and more with each revisit. I am still functioning at a basic level in the area of electronics, but am reasonably adept at figuring out what is going on and what is intended if I take it slowly and one step at a time. I am putting together a Murphy Super Rebel and am a month or so away from starting the Engine Installation/ Panel and Wiring. The majority of the panel goodies have been selected and on hand. I am trying to wrap up instrumentation for the 9 cyl 400 HP M-14PF Radial. Randy my partner and I have decided to go with your "All electric on a budget" system. Single Battery. We have a Skytronics 50 Amp. alternator and their regulator (haven't analyzed its features if any yet). and plan to install either a B&C 8 or 20 amp alternator on the vacuum pump pad. In the other two aircraft I have owned, one I built, a CH701 STOL amphib, I have only had a voltmeter to monitor the electrical system. In both cases they where digital and I found the information provided adequate to assess the health of the systems, neither has had any problems to date. My question for you concerns instrumentation for the electrical system of the SR. I know I want a digital voltmeter and I would like it to be a 2.25 round. Both Electronics International and Davtron make such an animal and both can be toggled between Volts and Amps. A Davtron Model, the M475VAA has dual shunts and can read voltage and two current flows. It can measure alternator output and charge and discharge of the battery. It has a three position toggle switch. Volts/ +,- Battery Amps/Alternator amps. I would appreciate your thoughts on the direction I should take on electrical system instrumentation given the availability of the above instruments and the usefulness of the information they provide. Thanks in Advance. Regards, Don Boardman & Partner Randy Bowers SR3500#130 "The Muskie" M-14PF Aerocet 3400 Amphibs Rome, NY ________________________________________________________________________________
From: "Cy Galley" <cgalley(at)qcbc.org>
Subject: Re: Constant discharge on the battery
Date: Feb 27, 2002
Two things. There is generally a switch on the field. There should be 12 volts on the field terminal of your regulator with the master turned on. If not there might be a blown fuse in that wire. The other thing that you must do is flash the field of a "new" generator to give the field enough magnetism to generate. Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh ----- Original Message ----- From: "Ed Perry" <eperry(at)san.rr.com> Subject: AeroElectric-List: Constant discharge on the battery Hi Everyone, I am currently flying a SuperCub and have been having trouble with the charging system. The AMP meter shows a constant discharge and the battery keeps going dead. We have replaced the Generator, Battery, generator circuit breaker, and voltage regulator with no success. What am I missing here? The AMPS gauge is a negative - zero - positive readout. There is no Volts gauge. Whatelse should I be looking at? Thank You, Ed Perry eperry(at)san.rr.com http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
Date: Feb 28, 2002
From: Frank and Dorothy <frankv(at)infogen.net.nz>
Subject: Re: Microair radio & xpdr amp
requirements > > >I've heard the Microair xpdr is now available in the US for sale. Do > > >you have a price for it and what are the amps for each unit? > >Saw it here in New Zealand. Asking price was NZ$2800, which should >translate to about US$1200, give or take a couple of hundred. Found the pamphlet on it today -- draws 0.5A whilst transmitting, 80mA while receiving. Frank. ________________________________________________________________________________
From: "Ross" <rmickey(at)ix.netcom.com>
Subject: Re: ElectrONic AH and DG?
Date: Feb 27, 2002
I am going with the Dynon EFIS. http://www.dynondevelopment.com/ There is also the EFIS/Lite from Blue Mountain Avionics. http://bluemountainavionics.com/ Ross Mickey RV6A ----- Original Message ----- From: "Michel Therrien" <mtherr(at)yahoo.com> Subject: AeroElectric-List: ElectrONic AH and DG? > > Hello group, > > I would like to have gyros or equivalent in my plane, > but I have not found simple electronic gyros yet. > > At one end of the scale, I found a device which > connects to a PDA so you see attitude information on > the PDA's screen. > > At the other end, I found integrated engine > instruments, attitude, altitude, airspeed, > temperature, direction, gps and whatever you can > imagine. > > Will there be any device available to simply replace > mechanic AH and DG in a unit of similar size? > > Thanks for your insight. > > > ===== > ---------------------------- > Michel Therrien CH601-HD > http://pages.infinit.net/mthobby > http://mthobby.pcperfect.com/ch601 > > http://greetings.yahoo.com > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Piers Herbert" <piers.herbert(at)ntlworld.com>
Subject: Re: speed reduction
Date: Feb 28, 2002
> You can use an LM317 regulator from Radio Shack to > build an adjustable power supply that will provide > the necessary, lower voltage for slower operation. I note you can also get a LM217 which is similar but specified for a wider temperature range (sub freezing). Would there be any point in using the wider temperature version, I suppose I might want to fly after the machine had been in sub freezing temperatures over night, but then as the thing generates heat it would warm up quickly. Is the LM317 compatible with DO 160, or is this not something we need to be concerned about? Piers ________________________________________________________________________________
Date: Feb 28, 2002
Subject: Re: toggle switch failure modes?
From: czechsix(at)juno.com
Bob, I'm not saying that your published architecture with the diodes falls short in any way. Just wondered why the function couldn't be replaced by a single toggle switch....not much savings, but it would be lower parts count and probably save a few bucks and an ounce or two.....one less thing to mount....no voltage drop (yeah, I know, not a problem to have a 0.7 volt drop). Just seems to me that it would work just as well with a toggle switch and even though the switch could break, it's not likely to do so unless actuated.....which means it would break when you need it most and at that point it wouldn't be much different than using the diode / toggle combo (i.e. the toggle could also break when you need the ESS bus...). So in the spirit of your statement on your website inviting peer review and comment on the wiring diagrams, I just wondered realistically if there's a toggle switch failure mode that would create a *statistically meaningful* problem in this scenario? I'll probably just put the diodes in....not a big deal....just don't see a compelling advantage.... --Mark _______ From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com> Subject: Re: AeroElectric-List: toggle switch failure modes? > >Bob, > >A couple days ago I posted a question about using a DPDT toggle switch for >the ESS bus, using it to replace the diode function you show on your >schematics. I didn't get a direct response but your response to another >post using a similar idea was that there are some good reasons to use the >diodes and that using a single switch results in a single point of failure. >A couple questions: first of all, what other advantages are there to >using the diodes besides their obvious function of keeping the current on >the ESS bus from feeding back into the main bus? No moving parts. Never seen one fail in service in an airplane. >Second, what kind of failure modes does a toggle switch have? I don't >know what it looks like inside....in a DPDT switch, can it break such that >neither position can make contact? Can the contacts in BOTH positions >weld together? Etc? Let's back up a bit. What don't you like about what you see in the wiring diagrams? Have you read and understand the failure tolerant design philosophy described in chapter 17 of the AeroElectric Connection? Where do you perceive that the diagrams published miss the mark? I'm not trying to avoid your questions I'm curious as to how the published architectures fall short. Bob . . . ________________________________________________________________________________
Date: Feb 28, 2002
From: Steve Kay <skay(at)optonline.net>
Subject: Re: Fuses/CB's
> Bob, would these devices be acceptable replacements for the remoted fuse. Sure would be > nice to keep everything in the fuseblock. -Steve > http://order.waytekwire.com/CGI-BIN/LANSAWEB?WEBEVENT+L2370635A7F820100748E044+M36+ENG > > >Also how exactly do you wire the CB off the fuse block? Your diagram only > >shows the CB connected to the fuse block, ie no connecting wire from the > >fuse block to the CB??? > > Opps . . . that should be drawn like the alternator field breaker > in figure Z-11 . . . a fusible link at the fuseblock extends the > bus up to a breaker mounted beside the DC POWER MASTER switch. > Need to fix that! > > Bob . . . > ________________________________________________________________________________
From: KahnSG(at)aol.com
Date: Feb 28, 2002
Subject: RE:generator
Ed: If you have a generator and not an alternator, you must polarize it at the voltage reg. when replacing parts before it will operate properly. Steve Springfield Auto Parts Co., Inc. ________________________________________________________________________________
Date: Feb 28, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Fuses/CB's
> > > Bob, would these devices be acceptable replacements for the remoted > fuse. Sure would be > > nice to keep everything in the fuseblock. -Steve I'm not particularly impressed with the little circuit breakers masquerading as fuses. Besides, one of the goals of using compact, prefabricated fuse blocks is to get them off the panel . . . and preferably out of reach. Since the ALT FIELD breaker might be subject to nuisance tripping, it's best left on the panel . . . like right next to the DC POWER MASTER. I show the S700-2-10 switch used for DC POWER MASTER to get the progressive OFF/BAT/BAT-ALT operation on one switch. The times that one wants to operate battery only are usually limited to ground maintenance operations. One could use the S700-2-3 switch to simply bring battery and alternator on and off together and pull the ALT FIELD breaker for battery only ground ops. The S700-2-5 is a much less expensive switch. > > > http://order.waytekwire.com/CGI-BIN/LANSAWEB?WEBEVENT+L2370635A7F820100748E044+M36+ENG > > > > >Also how exactly do you wire the CB off the fuse block? Your diagram only > > >shows the CB connected to the fuse block, ie no connecting wire from the > > >fuse block to the CB??? > > > > Opps . . . that should be drawn like the alternator field breaker > > in figure Z-11 . . . a fusible link at the fuseblock extends the > > bus up to a breaker mounted beside the DC POWER MASTER switch. > > Need to fix that! > > > > Bob . . . > > > > Bob . . . -------------------------- TEMPORARY WEBSITE ADDRESS: http://209.134.106.21 -------------------------- ________________________________________________________________________________
Date: Feb 28, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: toggle switch failure modes?
> >Bob, I'm not saying that your published architecture with the diodes >falls short in any way. Just wondered why the function couldn't be >replaced by a single toggle switch....not much savings, but it would be >lower parts count and probably save a few bucks and an ounce or >two.....one less thing to mount....no voltage drop (yeah, I know, not a >problem to have a 0.7 volt drop). Just seems to me that it would work >just as well with a toggle switch and even though the switch could break, >it's not likely to do so unless actuated.....which means it would break >when you need it most and at that point it wouldn't be much different >than using the diode / toggle combo (i.e. the toggle could also break >when you need the ESS bus...). So in the spirit of your statement on >your website inviting peer review and comment on the wiring diagrams, I >just wondered realistically if there's a toggle switch failure mode that >would create a *statistically meaningful* problem in this scenario? > >I'll probably just put the diodes in....not a big deal....just don't see >a compelling advantage.... We're probably splitting frog hairs . . . it's your airplane and you have to be comfortable with it. I can tell you that power distribution steering diodes are very commonly used on aircraft from King Airs on up and are much preferred to any mechanical substitute for overall system reliability. Anything that moves generally has 1/100th the reliability rating of it's solid-state counterpart. I did the first electronic speed controlled pitch trim to fly on the Lears about 20 years ago. When I did the MTBF studies the 50-60 piece collection of electronics showed a calculated MTBF in thousands of hours. When I factored in the super quality, hermetically sealed mill-spec auto-disconnect relay, the numbers fell to under 1000 hours. Nobody on the certified side of aviation will use a mechanical device in favor of a sold state one. Bob . . . ________________________________________________________________________________
Date: Feb 28, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: speed reduction
> > > > You can use an LM317 regulator from Radio Shack to > > build an adjustable power supply that will provide > > the necessary, lower voltage for slower operation. > >I note you can also get a LM217 which is similar but specified for a wider >temperature range (sub freezing). Would there be any point in using the >wider temperature version, I suppose I might want to fly after the machine >had been in sub freezing temperatures over night, but then as the thing >generates heat it would warm up quickly. Is the LM317 compatible with DO >160, or is this not something we need to be concerned about? None of these concerns are significant in the situation we are contemplating. Bob . . . ________________________________________________________________________________
Date: Feb 28, 2002
Subject: Aft battery cranking power
From: czechsix(at)juno.com
I'm thinking about installing the battery in my RV-8A in the aft location (behind baggage compartment) for CG reasons. However I'd like to use the smaller Odyssey battery instead of the big Concorde battery, and I'm wondering if the longer wire run would significantly impact starting capability? Assuming 250 A cranking current for a Skytech starter, and using 14 feet of #2 wire vs. only about 4 feet of #4 wire (for firewall battery location), my calculations using the published resistance values for #2 and #4 wire shows that there would be a .55 V drop on the long #2 run vs. a .25 V drop on the short #4 run. But my question is whether or not this is a meaningful, noticeable difference? Should I plan on using the bigger capacity battery because cranking may take longer with the aft location? Thanks, --Mark Navratil Cedar Rapids, Iowa RV-8A finish kit stuff.... ________________________________________________________________________________
From: "Ed Perry" <eperry(at)san.rr.com>
Subject: Re: Aeroelectric connection vs. CD Rom
Date: Feb 28, 2002
If it is the battery that should be easy to check....but didn't the battery get drained when he had the big battery installed under the seat? I think I remember it that way. Let me know if I can help.... Off to work, Ed Perry eperry(at)san.rr.com ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com> Subject: Re: AeroElectric-List: Aeroelectric connection vs. CD Rom > > > > >Can someone describe the difference between the Aeroelectric connection > >and the CD ROM? Is there a .pdf of the book on the CD, or is the CD > >supplemental information? > > The CD is a mirror of the wbsite . . . if you have a slow > internet connnection and then it's probably a good deal to > get the ROM so you don't have to download all the articles. > > Further the CD Rom has a copy of AC43-13b and ammendments on > it plus other data like fars. It includes a working copy > of a CAD program that will open, edit and print all of our > downloadable wirebook drawings. > > The CD will have updates to the 'Connection but not > a complete book. > > Bob . . . > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: Hebeard2(at)aol.com
Date: Feb 28, 2002
Subject: Polarized Connectors.
Bob, I sent the following message while I believe your site was down. Since I have received no answer I'll submit my question again. Would these Radio Shack polarized connectors be suitable for wing root disconnects? (p/n 274-151 male, 274-154 female at $.99 each) They are rated at 20 amps and cannot be connected the wrong way, and as the name says are interlocked. Harley Beard RV-6A finish kit. ________________________________________________________________________________
From: BAKEROCB(at)aol.com
Date: Feb 28, 2002
Subject: LR3B-14 Voltage Regulator
In a message dated 02/22/2002 2:52:43 AM Eastern Standard Time, "Robert L. Nuckolls, III" writes: <<.....skip..... one of the requirements I had for configuring the output stage was that the warning lamp should illuminate IF power were entirely removed from the regulator.....skip...... >> 2/28/2002 Hello Bob, The statement above that you wrote puzzles me. I went out to my airplane (still under construction) turned on my battery master and plugged in my battery charger to bring bus voltage above the point where the low voltage warning light would no longer flash. I then pulled the CB providing bus sense (and power source) to pin 3 of the LR3B-14 voltage regulator. The low voltage level light did not start to flash. Your statement above implied to me that it should flash. Is something wrong? Many thanks for your help. 'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - ?/?/? ________________________________________________________________________________
Date: Feb 28, 2002
From: Richard Dudley <rhdudley(at)att.net>
Subject: Re: Wig-Wag - FOLLOW-UP
Bob, The Galls controller is in on its way to you by priority mail. Richard Dudley Robert L. Nuckolls, III wrote: > > > > > >Bob, > >Earlier, I removed the yellow-brown combination from the switch and it > >had no effect. > >I joined the yellow-brow combination with the red wire and the logic > >table remains the same. > > When I developed the wiring diagrams posted > on my website, I had examples of the Galls products > to test on the bench and make sure that it > would work as advertised. If you'll send me your > flasher, I'll figure out what needs to be done > to make it work in your airplane. > > Ship it to 6936 Bainbridge Road, Wichita, KS > 67226-1008 > > Bob . . . > ________________________________________________________________________________
From: "W T Bartlett" <wtbartlett(at)Prodigy.net>
Subject: Re: ElectrONic AH and DG?
Date: Feb 28, 2002
I have trouble understanding. The model airplane people sell single axis ,solid state, Gyros for less than $70, and these have to differentiate between heavy control input and lighter input. Buy three and mount them at 90 deg. to each other and they will hold heading, altitude, and roll. Now we are up to $210 for a three axis autopilot. These are not directly usable by us because they require a radio control transmitter and receiver, less than $100 ( guess you could make a little box for the receiver and carry a transmitter with you) and they would be simpler if they were just hooked up to a display and servos. For $150 you can get a two axis autopilot that receives GPS and holds attitude and heading. They have other gyros that can distinguish between sky and ground (IR) and will right an out of control plane (also less than $150. Why is it that people who can build airplanes can't adapt these products? All the above products weigh less than 2 oz. Most of the trim servos are modified model airplane servos. What's the problem? Bill N7WB > Subject: Re: AeroElectric-List: ElectrONic AH and DG? > > > > > > > > >Will there be any device available to simply replace > >mechanic AH and DG in a unit of similar size? > > > >Thanks for your insight. > > > yes . . . but probably not this year . . . but > certainly within say 5 years. the technology > is here. it just needs to be applied in enough > OTHER consumer products to drive the prices down > to levels practical for our use. I've got > a 3-axis laser gyro on my bench right now > that's going to replace iron gyros in several > of our targets at RAC. We've built our last > iron gyro stabilized product. . . . and it's > only about $4,000 per axis. It was $10,000 > per axis the last time we considered it for > a target upgrade . . . about 6 years ago. > > Bob . . . ________________________________________________________________________________
Date: Feb 28, 2002
From: Tom Brusehaver <cozytom(at)mn.rr.com>
Subject: Re: ElectrONic AH and DG?
A lotta people try these in robots, they ain't very constant. CPU's like basic stamps have servo signal inputs and outputs so they are very easy to connect to computers. Remember an RC plane going 30-80MPH won't be going in a straight line for for more than a few minutes. Robots and our real airplanes we want to hold heading, altitude for maybe hours. The RC gyros just aren't up to the task. The mechanical ones precis, and the electronic ones drift. They can be correlated to other instruments (PNI makes a flux gate compass for about $80 motorola and others have pressure sensors for less than $100) and it could be done, just not easy. W T Bartlett wrote: > > I have trouble understanding. The model airplane people sell single axis > ,solid state, Gyros for less than $70, and these have to differentiate > between heavy control input and lighter input. Buy three and mount them at > 90 deg. to each other and they will hold heading, altitude, and roll. Now we > are up to $210 for a three axis autopilot. These are not directly usable by > us because they require a radio control transmitter and receiver, less than > $100 ( guess you could make a little box for the receiver and carry a > transmitter with you) and they would be simpler if they were just hooked up > to a display and servos. For $150 you can get a two axis autopilot that > receives GPS and holds attitude and heading. They have other gyros that can > distinguish between sky and ground (IR) and will right an out of control > plane (also less than $150. Why is it that people who can build airplanes > can't adapt these products? All the above products weigh less than 2 oz. > Most of the trim servos are modified model airplane servos. > What's the problem? > Bill N7WB ________________________________________________________________________________
Date: Feb 28, 2002
Subject: Re: Aft battery cranking power
From: Denis Walsh <deniswalsh(at)earthlink.net>
I've used both the concorde25 AH and the odyssey 17AH batts on my O-360 engine. The Odyssey cranks better, but theoretically has less reserve power. DLW 2/28/02 12:40, czechsix(at)juno.com at czechsix(at)juno.com wrote: > > I'm thinking about installing the battery in my RV-8A in the aft location > (behind baggage compartment) for CG reasons. However I'd like to use the > smaller Odyssey battery instead of the big Concorde battery, and I'm wondering > if the longer wire run would significantly impact starting capability? > Assuming 250 A cranking current for a Skytech starter, and using 14 feet of #2 > wire vs. only about 4 feet of #4 wire (for firewall battery location), my > calculations using the published resistance values for #2 and #4 wire shows > that there would be a .55 V drop on the long #2 run vs. a .25 V drop on the > short #4 run. But my question is whether or not this is a meaningful, > noticeable difference? Should I plan on using the bigger capacity battery > because cranking may take longer with the aft location? > > Thanks, > > --Mark Navratil > Cedar Rapids, Iowa > RV-8A finish kit stuff.... > > > > > > ________________________________________________________________________________
Date: Feb 28, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: ElectrONic AH and DG?
> > >I have trouble understanding. The model airplane people sell single axis >,solid state, Gyros for less than $70, and these have to differentiate >between heavy control input and lighter input. Buy three and mount them at >90 deg. to each other and they will hold heading, altitude, and roll. Now we >are up to $210 for a three axis autopilot. These are not directly usable by >us because they require a radio control transmitter and receiver, less than >$100 ( guess you could make a little box for the receiver and carry a >transmitter with you) and they would be simpler if they were just hooked up >to a display and servos. For $150 you can get a two axis autopilot that >receives GPS and holds attitude and heading. They have other gyros that can >distinguish between sky and ground (IR) and will right an out of control >plane (also less than $150. Why is it that people who can build airplanes >can't adapt these products? All the above products weigh less than 2 oz. >Most of the trim servos are modified model airplane servos. >What's the problem? I have some of these that I've been playing with. The problem is drift rate. While you're controlling a model airplane, you responding with control inputs based on what you SEE the model doing. Drift rates on the order of as much as 4-5 degrees per minute would still afford a ton of inertial stability for controlling the model. Drift rates on this order are okay for navigation too . . . when you have GPS data to provide once per second updates of true course and speed. The gyros used in both model airplanes and modern AH/DG replacements are not stable platforms like iron gyros. They're just rate sensors . . . so to know where up and north are, you have to initialize the system and then integrate rate with time to deduce new heading and whether or not you are straight and level . . . drift rates on the order of .1 degree/minute are desirable . . . not easy with a $75 hummer suitable for model helicopter stabilization. That $12K gizmo on my bench right now is laser-ring gyro that has drift rates on the order of .5 to 1 degree per minute . . . we use GPS enhancement to wash out drift. Further, this vehicle's total flight time is less than 3 minutes so we can live with and work with the drifts. Bob . . . ________________________________________________________________________________
Date: Feb 28, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: LR3B-14 Voltage Regulator
> >In a message dated 02/22/2002 2:52:43 AM Eastern Standard Time, "Robert L. >Nuckolls, III" writes: > ><<.....skip..... one of the requirements I had for configuring the output >stage was that the warning lamp should illuminate IF power were entirely >removed from the regulator.....skip...... >> > >2/28/2002 > >Hello Bob, The statement above that you wrote puzzles me. > >I went out to my airplane (still under construction) turned on my battery >master and plugged in my battery charger to bring bus voltage above the point >where the low voltage warning light would no longer flash. > >I then pulled the CB providing bus sense (and power source) to pin 3 of the >LR3B-14 voltage regulator. The low voltage level light did not start to >flash. Your statement above implied to me that it should flash. No, it should be on steady . . . and probably dimmer than normal brightness but it doesn't flash. Bob . . . ________________________________________________________________________________
Date: Feb 28, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Wig-Wag - FOLLOW-UP
> >Bob, > >The Galls controller is in on its way to you by priority mail. Very good. ________________________________________________________________________________
Date: Feb 28, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Aft battery cranking power
> >I'm thinking about installing the battery in my RV-8A in the aft location >(behind baggage compartment) for CG reasons. However I'd like to use the >smaller Odyssey battery instead of the big Concorde battery, and I'm >wondering if the longer wire run would significantly impact starting >capability? Assuming 250 A cranking current for a Skytech starter, and >using 14 feet of #2 wire vs. only about 4 feet of #4 wire (for firewall >battery location), my calculations using the published resistance values >for #2 and #4 wire shows that there would be a .55 V drop on the long #2 >run vs. a .25 V drop on the short #4 run. But my question is whether or >not this is a meaningful, noticeable difference? Should I plan on using >the bigger capacity battery because cranking may take longer with the aft >location? No, I got a number of RV-8 builders flying with 17 a.h. batteries, 2AWG feeders and enjoying excellent cranking performance. Bob . . . ________________________________________________________________________________
Date: Feb 28, 2002
Subject: Electrical Sys Instrumentation Ans Found.
From: Don Boardman <dboardm3(at)twcny.rr.com>
Hi Bob, Got into the archives for the first time today and see that my question on system instrumentation has been extensively covered. Sorry I didn't get to the archives earlier ... new at this list game. I went to your site looking for a description of the VLM-14 Volt/Ammeter but could not find it. Help. Regards, Don Boardman & Partner Randy Bowers SR3500#130 "The Muskie" M-14PF Aerocet 3400 Amphibs Rome, NY ________________________________________________________________________________
From: Hebeard2(at)aol.com
Date: Feb 28, 2002
Subject: Re: ElectrONic AH and DG?
Tom - Who is PNI, and how may they be contacted? Harley Beard, RV-6A finishing ________________________________________________________________________________
From: "Richard D. Fogerson" <rickf(at)velocitus.net>
Subject: Bob - I need help in selecting electrical system
Date: Feb 28, 2002
Hi Bob, I've read about electrical system options until I'm suffering from data overload. Unless you can suggest a better way, I will try to eat this elephant a bite at a time in a few e-mails. Let's say you were building a day (no lights), VFR only, crosscountry RV3. Modest power req'ts: RMI encoder (.15 amps) Engine Monitor (.15 amps) Navaid (.3 to 3.6 amps) 2 X E.I. (1.5 amps) GPS (.25 amps) Other standard electrical stuff like Microair radio & xpdr, contactors, and boost pump. Would you go with: 1) One annually replaced RG battery 2) Two RG batteries of equal size where oldest is replaced annually or 3) Two RG batteries of unequal size where both are replaced every one or two years. and what size(s) would it/they be? Thanks Bob, Rick Fogerson Fuselage soon Boise, ID x ________________________________________________________________________________
From: "Lonnie Benson" <lonben(at)erols.com>
Subject: Re: ElectrONic AH and DG?
Date: Mar 01, 2002
Try www.pnicorp.com for info on the company. Formerly called Precision Navigation, Inc. ----- Original Message ----- From: <Hebeard2(at)aol.com> Subject: Re: AeroElectric-List: ElectrONic AH and DG? > > Tom - > > Who is PNI, and how may they be contacted? > > Harley Beard, RV-6A finishing > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
Date: Mar 01, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Electrical Sys Instrumentation Ans
Found. > >Hi Bob, > >Got into the archives for the first time today and see that my question on >system instrumentation has been extensively covered. Sorry I didn't get to >the archives earlier ... new at this list game. > >I went to your site looking for a description of the VLM-14 Volt/Ammeter but >could not find it. There are two catalog index/order forms on our website. One for the stuff I sell as AEC and one for B&C who has taken over the stuff I used to sell. Each order form is also the index for descriptions of products. Note that on catalog page http://www.aeroelectric.com/Catalog/AECcatalog.html about 2/3rds of way down the page, you find a listing for the VLM-14 . . . clicking on the underlined portion of the listing will link you to: http://www.aeroelectric.com/Catalog/instrmnt/instrmnt.html which is the description of the product. Same same for the B&C order form. Filling out these forms and hitting submit at the bottom sends the order to different mailboxes. Bob . . . ________________________________________________________________________________
Date: Mar 01, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Aft battery cranking power
> > >I've used both the concorde25 AH and the odyssey 17AH batts on my O-360 >engine. The Odyssey cranks better, but theoretically has less reserve >power. It's not just theory but fact . . . "reserve power" or capacity is only loosely related to "cranking amps" or (more properly) internal impedance. I can show you 1.5 a.h. batteries that will dump out more than 1000 amps. A 12v array of these cells weighs about 2#. On the other hand, there are 35 a.h. batteries weighing in at over 30# that won't dump more than 400 . . . Performance in the three tasks of batteries: (1) start (2) regulate and (3) standby power can be independently tweaked by design of the battery. Regulation is dead-nuts simple . . . any battery will do. The need for capacity is a function of how you've architectured your system . . . if you have two engine driven power sources, you don't need a lot of capacity. This leaves only engine cranking performance which can vary considerably from brand to brand of battery in the same size. The Odyssey batteries are descendant from the original RG jelly-roll batteries patented by Gates about 30 years ago. They are renowned for their very low cell impedance. Bob . . . ________________________________________________________________________________
Date: Mar 01, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Polarized Connectors.
> >Bob, > >I sent the following message while I believe your site was down. Since I have >received no answer I'll submit my question again. > >Would these Radio Shack polarized connectors be suitable for wing root >disconnects? (p/n 274-151 male, 274-154 female at $.99 each) They are rated >at 20 amps and cannot be connected the wrong way, and as the name says are >interlocked. There are a gob of products out there that are fairly suitable to this task. The only down side of ALL of them is their 7-strand, automotive wire with PVC insulation. Overlooking this relatively minor flaw one can press them into wing disconnect duty with techniques show as follows: http://209.134.106.21/articles/wingwire/con1.jpg http://209.134.106.21/articles/wingwire/con2.jpg http://209.134.106.21/articles/wingwire/con3.jpg http://209.134.106.21/articles/wingwire/con4.jpg Haven't had time to do the Shop Notes for this piece but the pictures are up . . . Bob . . . ________________________________________________________________________________
Date: Mar 01, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: I need help in selecting electrical system
> > >Hi Bob, >I've read about electrical system options until I'm suffering from data >overload. Unless you can suggest a better way, I will try to eat this >elephant a bite at a time in a few e-mails. > >Let's say you were building a day (no lights), VFR only, crosscountry >RV3. Modest power req'ts: > >RMI encoder (.15 amps) >Engine Monitor (.15 amps) >Navaid (.3 to 3.6 amps) >2 X E.I. (1.5 amps) >GPS (.25 amps) >Other standard electrical stuff like Microair radio & xpdr, contactors, >and boost pump. > >Would you go with: > >1) One annually replaced RG battery >2) Two RG batteries of equal size where oldest is replaced annually or >3) Two RG batteries of unequal size where both are replaced every one or >two years. > >and what size(s) would it/they be? For this kind of service I'd go with Figure Z-11, 40A alternator and an 17 a.h. battery replaced every two years or so. I presume you ARE going to carry hand held backups like a GPS310 and JHP-520 so in a daytime cross country environment it's not critical that ANYTHING on the panel be working. Given the demonstrated reliability of modern alternators and batteries, I'd keep it light, simple and low cost. Z-11 is the ticket. If you have a vacuum pump pad open now or in the future, upgrade by adding the SD-8 alternator and replace the battery when it finally won't crank the engine any more. Bob . . . ________________________________________________________________________________
From: "Piers Herbert" <piers.herbert(at)ntlworld.com>
Subject: Re: Polarized Connectors.
Date: Mar 01, 2002
I found these Neutrik "speakon" connectors in the Maplin catalogue (UK). I suppose they would be available in the US as well. There are chassis sockets and line plugs, 20A continuous rated - could be suitable? http://www.neutrik.com/content/products/products_group.asp?id=204_54361 Piers ________________________________________________________________________________
Date: Mar 01, 2002
From: Jaye and Scott Jackson <jayeandscott(at)shaw.ca>
Subject: Grounding strobe power pack
Bob: I have located the strobe power pack just behind the back wall of the baggage compartment and was wondering if it might cause any noise-related problems if I were to ground the ground lead right there instead of running a wire all the way back to the firewall "forest of tabs" that I've used for everything else up to this point. Thanks, Scott in Vancouver ________________________________________________________________________________
Date: Mar 01, 2002
Subject: Lightweight starters...
From: czechsix(at)juno.com
I'm a bit confused about the lightweight starters currently available. It was my understanding and general impression that most RV builders were getting the Skytech starter because it was the lightest, best all-around starter. But I've heard a few less than positive things about Skytech's track record recently. I looked at the Magnaflite starter, which appears to be a new motor bolted on to the old "Bendix drive"....it's roughly comparable in price to a Skytech, is 0.1 pounds lighter, and makes the claim that it has more torque than "any other lightweight starter out there". I haven't looked at the B&C unit but if I recall correctly it was heavier and more expensive than the Skytech. So, is the Skytech getting a lot of use simply because Vans sells it (both separately and on their new Lycomings) or is there something I'm missing? Thanks, --Mark Navratil Cedar Rapids, Iowa RV-8A finish kit stuff.... ________________________________________________________________________________
Date: Mar 01, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Grounding strobe power pack
> > >Bob: > I have located the strobe power pack just behind the back wall of the > baggage compartment and was wondering if it might cause any noise-related > problems if I were to ground the ground lead right there instead of > running a wire all the way back to the firewall "forest of tabs" that > I've used for everything else up to this point. >Thanks, >Scott in Vancouver No, landing lights, taxi lights, strobe power supplies, and pitot heaters can get local grounds. IF, in the relatively rare case you do get some noise from the strobe supply, it's a 99.5% bet that it's conducted noise that is easily filtered at the power supply. Bob . . . ________________________________________________________________________________
Date: Mar 01, 2002
From: "Gary A. Sobek" <rv6flier(at)yahoo.com>
Subject: Re: Lightweight starters...
--- czechsix(at)juno.com wrote: > > I'm a bit confused about the lightweight starters currently > available. It was my understanding and general impression that most > RV builders were getting the Skytech starter because it was the > lightest, best all-around starter. But I've heard a few less than > positive things about Skytech's track record recently. I looked at > the Magnaflite starter, which appears to be a new motor bolted on to > the old "Bendix drive"....it's roughly comparable in price to a > Skytech, is 0.1 pounds lighter, and makes the claim that it has more > torque than "any other lightweight starter out there". I haven't > looked at the B&C unit but if I recall correctly it was heavier and > more expensive than the Skytech. So, is the Skytech getting a lot of > use simply because Vans sells it (both separately and on their new > Lycomings) or is there something I'm missing? > > Thanks, > > --Mark Navratil > Cedar Rapids, Iowa > RV-8A finish kit stuff.... > > Mark: The SkyTec is the start that is on the new Lycoming and was one of the first to hit the market with a good price. At about 4 years and 950 hours, I had the solenoid go out. That was a $37 part that came to around $43 delivered. My fried Paul Rosales had his go out at about 750-800 hours. I know of one other that had the selonid go out. The SkyTec starts my engine typically with 3 blades or less. I am using Bendix mags and only one has an impulse coupling. ===== Gary A. Sobek "My Sanity" RV-6 N157GS O-320 Hartzell, 1,010.4+ Flying Hours So. CA, USA http://SoCAL_WVAF.tripod.com http://greetings.yahoo.com ________________________________________________________________________________
Date: Mar 01, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Lightweight starters...
> >I'm a bit confused about the lightweight starters currently available. It >was my understanding and general impression that most RV builders were >getting the Skytech starter because it was the lightest, best all-around >starter. But I've heard a few less than positive things about Skytech's >track record recently. I looked at the Magnaflite starter, which appears >to be a new motor bolted on to the old "Bendix drive"....it's roughly >comparable in price to a Skytech, is 0.1 pounds lighter, and makes the >claim that it has more torque than "any other lightweight starter out >there". I haven't looked at the B&C unit but if I recall correctly it was >heavier and more expensive than the Skytech. So, is the Skytech getting a >lot of use simply because Vans sells it (both separately and on their new >Lycomings) or is there something I'm missing? B&C produced the first successful lightweight starter design. It's been STCd for longer than I care to remember and enjoys strong user support. Robinson Helicopter has used nothing but B&C starters for about 15 years and they're very happy with the decision. B&C has participated in dozens of conversations with Lycoming and Continental about supplying volume quantities to support their engine production. In every case (until a few months ago) both Lyc and Cont thought they could do better. Lyc has gone through several iterations of sub- contracted and outside starters (including Skytech) over the past 10 years. None have matched the performance and reliability of the B&C starter. Continental tested a B&C starter on their new IO-240 and pronounced the starter "indestructible" after 5000 starts in the test cell. Then they proceeded to attempt a clone of the B&C design which proved to be a poor business decision. Seems their clone has dropped too much metal in too many engines. I belive they're currently negotiating with B&C for the starter they tested. Virtually all competition to the B&C starters use PM motors . . . lighter, cheaper and easier to build. I was involved in Bill's deliberations to consider offering a PM motor version of his design. After several months of consideration, we agreed that it would add no performance value. PM motors have some performance downside . . . most notability the higher inrush current and steeper current vs. RPM curves characteristic of a parallel wound motor. Bill was unwilling to give up superior system integration issues and elected to stay with the wound field design. Further, B&C designs use all ball bearing construction and no plastic structural parts or gears. B&C starter pinion gears are directly engaged with the ring gear by a solenoid. Many folks report satisfactory performance from other starters. In the bigger picture, B&C's track record with Robinson stands in sharp contrast with attempts by both Lyc and Cont to do better for less money. Yeah, the B&C starters are more expensive but they've got more stuff in 'em and they're harder to build. I'll suggest that trials in the marketplace have proven B&C starters to be good value. Bob . . . ________________________________________________________________________________
From: "Richard D. Fogerson" <rickf(at)velocitus.net>
Subject: Re: I need help in selecting electrical system
Date: Mar 01, 2002
Bob, Some further clarification, the GPS I'm leaning toward is the Skymap II from Bendix King that is charged by the aircraft electrical system but has NiCad battery backup so it is not a problem. However, I want to use the Microair comm and xpdr (don't like handhelds) and I forgot to mention that the alternator/regulator will be B&C but the starter will have to be Skytech (for unrelated reasons). Does this change your recommendation to something else? > > > >Hi Bob, > >I've read about electrical system options until I'm suffering from data > >overload. Unless you can suggest a better way, I will try to eat this > >elephant a bite at a time in a few e-mails. > > > >Let's say you were building a day (no lights), VFR only, crosscountry > >RV3. Modest power req'ts: > > > >RMI encoder (.15 amps) > >Engine Monitor (.15 amps) > >Navaid (.3 to 3.6 amps) > >2 X E.I. (1.5 amps) > >GPS (.25 amps) > >Other standard electrical stuff like Microair radio & xpdr, contactors, > >and boost pump. > > > >Would you go with: > > > >1) One annually replaced RG battery > >2) Two RG batteries of equal size where oldest is replaced annually or > >3) Two RG batteries of unequal size where both are replaced every one or > >two years. > > > >and what size(s) would it/they be? > > > For this kind of service I'd go with Figure Z-11, 40A alternator > and an 17 a.h. battery replaced every two years or so. I presume > you ARE going to carry hand held backups like a GPS310 and > JHP-520 so in a daytime cross country environment it's not > critical that ANYTHING on the panel be working. Given the > demonstrated reliability of modern alternators and batteries, > I'd keep it light, simple and low cost. Z-11 is the ticket. > If you have a vacuum pump pad open now or in the future, > upgrade by adding the SD-8 alternator and replace the > battery when it finally won't crank the engine any more. > > Bob . . . > > > > > > ________________________________________________________________________________
Date: Mar 01, 2002
From: deltab(at)erols.com
Subject: Re: Fuses/CB's
How inconvenient does it become to practice manual gear extension procedures if the breaker is WAY out of the way and not a pull out type? I remember from my Arrow check-out time either the instructor or myself using that feature alot. Bernie C. "Robert L. Nuckolls, III" wrote: > > > > > > > >Hi Bob, > > > > Also you have a CB for the hyd pump...This seems to make sense > >too, since there isn't actually an on-off switch for the pump and it would > >be nice to have "override" control. Is this the rationale for the hyd pump > >CB? Are there any other systems that you would think would be nice to have > >this control over, ie use a CB over a fuse even tough you are going > >primarily with fuses? > > > Even if you use a breaker for the pump, I wouldn't put it on > the panel . . . one of the goals of clean system design > is to keep those kind of current carrying conductors away > from the panel. I did have one Glasair builder mount his > pump circuit breaker low on the right side kick panel so > he could reach it if he stuck a contactor. This should be > a rare event and if it happens, you can treat it just like > an alternator out event. Kill the main bus to shut off > the pump. Continue to intended destination and turn the > main bus on long enough to cycle the gear . . . or leave > it off and use the primary gear extension system (the manual > one that ALWAYS works) to lower the gear. > > Bob . . . > ________________________________________________________________________________
Date: Mar 01, 2002
From: deltab(at)erols.com
Subject: Re: Alternator windings
My modern (2001) Toyota alternator does this. Probably ND. Bernie C. "Robert L. Nuckolls, III" wrote: > > . . . adding two more diodes to the > rectifier array will increase output by as much > as 10%. > > > Bob . . . > ________________________________________________________________________________
Date: Mar 02, 2002
From: Jim and Lucy <jpollard(at)mnsi.net>
Subject: spark ign. question
Here is a question that I have been wondering about for 20 years. Many times I have had a motor that was hard to start due to fouled plugs or flooded plugs or low battery.Often pulling a spark plug wire off the plug and leaving a gap between the wire and the plug somehow makes the spark more powerfull. The engine will often fire and start on that cylinder and if it a multi-cylinder engine the others may catch. Sometimes the engine will quit when the gap is removed. I learned this on an old triumph motorcycle and have done it on lawnmowers and golfcarts, electronic and points ignitions. I know it works and is not just my imagination. So anyone got an electrical explanation for this? My guess is that the coil discharge is held back by the gap. When it finally jumps it is a bit shorter duration but more intense?? Here is the airplane content I used this technique to get a zenair soob running while setting up the carb. It was way too rich and fouled the plugs bad. We were only ground running so did not want to ruin more than one set of plugs while setting the carb. thanks Jim Pollard ch601hds ea81 ________________________________________________________________________________
From: "David Swartzendruber" <dswartzendruber(at)earthlink.net>
Subject: Lightweight starters...
Date: Mar 02, 2002
Yes, the new Lycoming engines from Van's come with a Sky-Tec starter, but that is only because Van's has spec'd the engine that way from Lycoming. The Magnaflite is now the standard starter at Lycoming. All their test cells use Magnaflite starters. When you're buying as many starters as Lycoming does, it's hard to pay the price for a B&C. As individuals, choosing an expensive starter only has to be a one time event. David Swartzendruber Wichita > > Mark: > > The SkyTec is the start that is on the new Lycoming and was > one of the first to hit the market with a good price. At > about 4 years and 950 hours, I had the solenoid go out. That > was a $37 part that came to around $43 delivered. My fried > Paul Rosales had his go out at about > 750-800 hours. I know of one other that had the selonid go out. > > The SkyTec starts my engine typically with 3 blades or less. I am > using Bendix mags and only one has an impulse coupling. > ________________________________________________________________________________
Date: Mar 02, 2002
From: klehman <klehman(at)albedo.net>
Subject: battery cranking power
Are these available at reasonable cost yet? Saw one at OSK a few years ago then never heard anything more. I had hoped to mount one beside the starter. Lighter than running a heavy wire from the battery. It would also reduce the total battery weight since I'm carrying two alternators anyway. Ken >It's not just theory but fact . . . "reserve power" or capacity >is only loosely related to "cranking amps" or (more properly) >internal impedance. I can show you 1.5 a.h. batteries that will >dump out more than 1000 amps. A 12v array of these cells weighs >about 2#. ________________________________________________________________________________
Date: Mar 02, 2002
From: Robert McCallum <robert.mccallum2(at)sympatico.ca>
Subject: Re: spark ign. question
What happens with a fouled plug (or a plug with too little gap) is that there is a low resistance path for the electricity to follow and therefore the spark occurs at a lower voltage. This low voltage spark is less intense and contains less energy than if a higher resistance path is established thus causing a higher voltage to build up before flash over. This higher voltage causes a more intense higher energy spark. This is the theory employed by resistor spark plugs or "intensifier gap" spark plugs used in many cars. A low voltage spark jumping a few thousandths of an inch gap in a switch is a relatively low energy spark and causes very little damage. The spark across a normal spark plug gap of .025 to .100 inches requires a few thousand volts and fairly rapidly burns away the electrodes requiring plug replacement regularly. A bolt of lightening jumps a very large gap, requires millions of volts and causes instantaneous mass destruction. The amount of damage or wear is a rough measure of the energy in the spark A higher energy spark imparts more energy to the mixture in the cylinder and hence results in easier starting. Very simplified explanation, but basically what goes on. Bob McC Jim and Lucy wrote: > > Here is a question that I have been wondering about for 20 > years. Many times I have had a motor that was hard to start > due to fouled plugs or flooded plugs or low battery.Often pulling a spark > plug wire off the plug and leaving a gap between the wire > and the plug somehow makes the spark more powerfull. > The engine will often fire and start on that cylinder and if > it a multi-cylinder engine the others may catch. Sometimes > the engine will quit when the gap is removed. I learned this > on an old triumph motorcycle and have done it on lawnmowers > and golfcarts, electronic and points ignitions. I know it works > and is not just my imagination. > So anyone got an electrical explanation for this? My guess > is that the coil discharge is held back by the gap. When it > finally jumps it is a bit shorter duration but more intense?? > > Here is the airplane content > > I used this technique to get a zenair soob running while > setting up the carb. It was way too rich and fouled the > plugs bad. We were only ground running so did not want to ruin > more than one set of plugs while setting the carb. > > thanks > > Jim Pollard > ch601hds > ea81 > ________________________________________________________________________________
Date: Mar 02, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: battery cranking power
> >Are these available at reasonable cost yet? Saw one at OSK a few years >ago then never heard anything more. I had hoped to mount one beside the >starter. Lighter than running a heavy wire from the battery. It would >also reduce the total battery weight since I'm carrying two alternators >anyway. >Ken Hmmmm . . . they WERE . . sorta. I just tried to log onto their website at boldertmf.com and the site failed to come up. These folks had been working on a miniature version of the jelly-roll cell in a 1.5 a.h. configuration. I've been following them loosely for several years. I've had samples of the cells to play with. When new, they performed very well but they were having service life problems. Bolder produced a product call Secure Start which I've seen stores in the past. It sold for about $100 and had an array of cells in a 12v battery along with built in wall charger, flashlight and big battery clips to hook to your dead car battery for a dead-battery resurrection. Seems they've dropped out of sight. Okay, the next contender would be the folks who do the Startstick. See: http://www.startstick.com/Products.html most of their 12 products are bigger in capacity . . . 10 a.h. or so is advertised. However here's an interesting item: http://www.startstick.com/Products.html#UltraStartRed This is a 4.4#, 5 a.h. product that claims starting current capability. Don't know anything about these guys. I'll order some samples one of these days. They use prismatic cell construction (stacked plates) as opposed to the jelly-roll cell . . . To date, the most and only successful jelly-roll cells with any track record are the Hawker 2 a.h. cells and the Optima 25 a.h. products (both originally Gates). Guess the Bolder folks have tossed in the towel. Startstick is the next one to watch. Bob . . . ________________________________________________________________________________
Date: Mar 02, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Fuses/CB's
> >How inconvenient does it become to practice manual gear extension >procedures if the >breaker is WAY out of the way and not a pull out type? I remember from my >Arrow >check-out time either the instructor or myself using that feature alot. Turn the E-BUS ALT FEED - ON, DC POWER MASTER - OFF and lower the gear with the manual system. Bob . . . ________________________________________________________________________________
Date: Mar 02, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: I need help in selecting electrical system
> > >Bob, >Some further clarification, the GPS I'm leaning toward is the Skymap II from >Bendix King that is charged by the aircraft electrical system but has NiCad >battery backup so it is not a problem. However, I want to use the Microair >comm and xpdr (don't like handhelds) and I forgot to mention that the >alternator/regulator will be B&C but the starter will have to be Skytech >(for unrelated reasons). > >Does this change your recommendation to something else? Yes. New battery every two years max . . . or every annual just for the hell of it. If you don't mind running a capacity check every 6 months or so after the first year, then keep the battery until it drops below 4 hours sustained e-bus loads. Bob . . . ________________________________________________________________________________
Date: Mar 02, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: spark ign. question
> >Here is a question that I have been wondering about for 20 >years. Many times I have had a motor that was hard to start >due to fouled plugs or flooded plugs or low battery.Often pulling a spark >plug wire off the plug and leaving a gap between the wire >and the plug somehow makes the spark more powerfull. >The engine will often fire and start on that cylinder and if >it a multi-cylinder engine the others may catch. Sometimes >the engine will quit when the gap is removed. I learned this >on an old triumph motorcycle and have done it on lawnmowers >and golfcarts, electronic and points ignitions. I know it works >and is not just my imagination. > So anyone got an electrical explanation for this? My guess >is that the coil discharge is held back by the gap. When it >finally jumps it is a bit shorter duration but more intense?? > >Here is the airplane content > >I used this technique to get a zenair soob running while >setting up the carb. It was way too rich and fouled the >plugs bad. We were only ground running so did not want to ruin >more than one set of plugs while setting the carb. How does fouling a plug trash it? I used to clean and re-gap my plugs regularly . . . on old engines, it wasn't uncommon to find one with more crud on it than the others but 15 seconds in the plug cleaner made it indistinguishable from the others. I've hear of this "trick" before but I'm at a loss to explain it. Adding to the total spark gap length can only raise the path resistance which makes the event shorter in time. Bob . . . ________________________________________________________________________________
From: "David Carter" <dcarter(at)datarecall.net>
Subject: Re: spark ign. question
Date: Mar 02, 2002
Here's an interesting thing about spark plugs: In 1956 my friend's dad had a '56 Chevy with "power pack" V-8 engine and stick shift - awesome performer. One weekend the engine is missing so 3 of us teenage experts start troubleshooting. First thing we do is check the plugs - and cleaned them. No help. Then took 6 good plugs out of my non-missing 1954 Ford 6 cyl and put them in the V-8 - no help. We had spark at wires and tops of plugs, so ignition system was OK. Seemed to be getting gas OK. Sooo, looks really serious - we start shopping for a place to pull the heads and do a valve job (no, we didn't do a compression check - ignorant). Well, some kind soul stopped us and had us buy 8 new plugs - fixed the problem. Only thing I figure is that spark plugs that worked in my 7.6 to 1 compression ratio Ford 6 wouldn't fire under the higher pressures in the 10.5 to 1 V-8. Subsequent life experience confirmed that higher compression requires better/different plugs than what will work in a low compression engine. Cleaning? I used to clean my plugs in the Ford, and later, a VW, at 10,000 miles, then replace at 20,000. Cleaning at 20,000 didn't help them work correctly. What deteriorates? Not visible to the naked eye. Must be "spark plug black magic" - until there's some "physics" involved. David Carter > > > >Here is a question that I have been wondering about for 20 > >years. Many times I have had a motor that was hard to start > >due to fouled plugs or flooded plugs or low battery.Often pulling a spark > >plug wire off the plug and leaving a gap between the wire > >and the plug somehow makes the spark more powerfull. Bob said, > How does fouling a plug trash it? I used to clean > and re-gap my plugs regularly . . . on old engines, > it wasn't uncommon to find one with more crud on it > than the others but 15 seconds in the plug cleaner > made it indistinguishable from the others. > > I've hear of this "trick" before but I'm at a loss > to explain it. Adding to the total spark gap length > can only raise the path resistance which makes the > event shorter in time. > > Bob . . . ________________________________________________________________________________
Date: Mar 02, 2002
From: Robert McCallum <robert.mccallum2(at)sympatico.ca>
Subject: Re: spark ign. question
True, but the higher resistance means the energy has to build to a higher level before it jumps the gap. This greater energy being dissipated across the plug gap creates a hotter spark although as you state the duration of the spark may be shorter. If the fire starts within this time frame you're away. If not, then the "trick" didn't work this time, but it often does. If you think of an ignition coil (or Mag) as being similar to a large capacitor charging up until the energy is released by the fact that the voltage built high enough to jump a spark gap, then the larger the gap the more energy is stored before the spark jumps and the more energy is released in the resultant spark Bob McC "Robert L. Nuckolls, III" wrote: > I've hear of this "trick" before but I'm at a loss > to explain it. Adding to the total spark gap length > can only raise the path resistance which makes the > event shorter in time. > > Bob . . . ________________________________________________________________________________
Date: Mar 02, 2002
From: Michel Therrien <mtherr(at)yahoo.com>
Subject: Re: ElectrONic AH and DG?
Is anybody here flying using one of these electronic compasses? See: http://www.pnicorp.com/compass-products-and-digital-compasses/v550-digital-vehicle-compass.html --- Lonnie Benson wrote: > Benson" > > Try www.pnicorp.com for info on the company. > Formerly called Precision > Navigation, Inc. > > ----- Original Message ----- > From: <Hebeard2(at)aol.com> > To: > Subject: Re: AeroElectric-List: ElectrONic AH and > DG? > > > Hebeard2(at)aol.com > > > > Tom - > > > > Who is PNI, and how may they be contacted? > > > > Harley Beard, RV-6A finishing > > > > > http://www.matronics.com/browselist/aeroelectric-list > > > > > > > > Forum - > Contributions of > any other form > > latest messages. > other List members. > > aeroelectric-list(at)matronics.com > http://www.matronics.com/subscription > http://www.matronics.com/photoshare > http://www.matronics.com/browselist/aeroelectric-list > http://www.matronics.com/search > http://www.matronics.com/archives > http://www.matronics.com/emaillists > > > > > ===== ---------------------------- Michel Therrien CH601-HD http://pages.infinit.net/mthobby http://mthobby.pcperfect.com/ch601 http://sports.yahoo.com ________________________________________________________________________________
Date: Mar 02, 2002
From: Michel Therrien <mtherr(at)yahoo.com>
Subject: Alternator B-lead fuse question
I found an in-line fuse holder with 50 and 60 amps plug-in fuses this morning. Is this good for our application in place of a Current Limiter limiter? See: http://mthobby.pcperfect.com/dcp01418.jpg Michel ===== ---------------------------- Michel Therrien CH601-HD http://pages.infinit.net/mthobby http://mthobby.pcperfect.com/ch601 http://sports.yahoo.com ________________________________________________________________________________
Date: Mar 03, 2002
From: Frank and Dorothy <frankv(at)infogen.net.nz>
Subject: Re: ElectrONic AH and DG?
At 08:26 3/03/2002, you wrote: > >Is anybody here flying using one of these electronic >compasses? > >See: >http://www.pnicorp.com/compass-products-and-digital-compasses/v550-digital-vehicle-compass.html Nice looking device, but I'm not using one. What I am doing is a research project using 3D magnetometers as part of an attitude sensing system. The primary intent isn't for use in aircraft, but, as you might guess, that is a constant consideration. It's possible that combining this with 3D rate gyros might result in a relatively cheap electronic AH or DG. Frank. ________________________________________________________________________________
Date: Mar 02, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: spark ign. question
> > >True, but the higher resistance means the energy has to build to a higher >level before it jumps the >gap. This greater energy being dissipated across the plug gap creates a >hotter spark although as you >state the duration of the spark may be shorter. If the fire starts within >this time frame you're >away. If not, then the "trick" didn't work this time, but it often does. >If you think of an >ignition coil (or Mag) as being similar to a large capacitor charging up >until the energy is >released by the fact that the voltage built high enough to jump a spark >gap, then the larger the gap >the more energy is stored before the spark jumps and the more energy is >released in the resultant >spark Hmmm . . . my physics book says energy stored on a capacitor is joules (watt seconds) = volts squared times capacitance divided by 2. Hence a 100 uF capacitor charged to 300 volts stores 4.5 joules of energy. An inductor's storage is amps squared times inductance divided by two . . . If memory serves me correctly, my ol' Chevy spark coil primary was about 10 millihenries charged to 2A for a potential energy storage of 20 millijoules. When we rewound them for transistor ignition, we'd pull off the primary and wind it back on with half the turns and double the wire. Half turns gave us 2.5 millihenries of inductance but we would charge it with about 10 amps for a storage of 125 millijoules of energy. All other things being constant and irrespective of whether the system is inductive or capacitive storage, adding a spark gap in series with the gap in the plug would simply allow a fixed amount of energy to be dissipated in two places instead of one. I'm having trouble figuring out how adding the second gap outside the cylinder improves performance for the gap inside. Bob . . . ________________________________________________________________________________
Date: Mar 02, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Alternator B-lead fuse question
> >I found an in-line fuse holder with 50 and 60 amps >plug-in fuses this morning. > >Is this good for our application in place of a Current >Limiter limiter? We talked about this a few weeks ago. While these holders will indeed mount the larger 70A cousins to the ATC fuses, they're pre-wired with 10AWG wire. I wouldn't use them with any alternator larger than 40A. Bob . . . ________________________________________________________________________________
Date: Mar 02, 2002
From: Michel Therrien <mtherr(at)yahoo.com>
Subject: Re: Alternator B-lead fuse question
The one I have appears to be wired with no 8 wire. This said, is it OK? Discussing this, I also saw another in-line fuse holder which supports large tubular fuses. It is a heavy plastic two-parts tube in which you insert the fuse and you screw one part into the other. That was the first time I saw one for big fuses like that (about 1/4" or 5/16" in diameter). The wire with that one is definitively a no 8 as it is written on it (with a PVC jacket). Would this be good? --- "Robert L. Nuckolls, III" wrote: > Nuckolls, III" > > Therrien > > > >I found an in-line fuse holder with 50 and 60 amps > >plug-in fuses this morning. > > > >Is this good for our application in place of a > Current > >Limiter limiter? > > > We talked about this a few weeks ago. While > these holders will indeed mount the larger > 70A cousins to the ATC fuses, they're pre-wired > with 10AWG wire. I wouldn't use them with any > alternator larger than 40A. > > Bob . . . > > > > Forum - > Contributions of > any other form > > latest messages. > other List members. > > aeroelectric-list(at)matronics.com > http://www.matronics.com/subscription > http://www.matronics.com/photoshare > http://www.matronics.com/browselist/aeroelectric-list > http://www.matronics.com/search > http://www.matronics.com/archives > http://www.matronics.com/emaillists > > > > > ===== ---------------------------- Michel Therrien CH601-HD http://pages.infinit.net/mthobby http://mthobby.pcperfect.com/ch601 http://sports.yahoo.com ________________________________________________________________________________
Date: Mar 02, 2002
From: Finn Lassen <finnlassen(at)netzero.net>
Subject: Re: spark ign. question
Bob, in a distributor-less system it may make sense that the fouled plug may load down the coil so it's never allowed to build up to full voltage. If you create an extra gap, it will build up to full voltage and probably result in a higher voltage across the fouled plug. Finn "Robert L. Nuckolls, III" wrote: > > > > >Here is a question that I have been wondering about for 20 > >years. Many times I have had a motor that was hard to start > >due to fouled plugs or flooded plugs or low battery.Often pulling a spark > >plug wire off the plug and leaving a gap between the wire > >and the plug somehow makes the spark more powerfull. > >The engine will often fire and start on that cylinder and if > >it a multi-cylinder engine the others may catch. Sometimes > >the engine will quit when the gap is removed. I learned this > >on an old triumph motorcycle and have done it on lawnmowers > >and golfcarts, electronic and points ignitions. I know it works > >and is not just my imagination. > > So anyone got an electrical explanation for this? My guess > >is that the coil discharge is held back by the gap. When it > >finally jumps it is a bit shorter duration but more intense?? > > > >Here is the airplane content > > > >I used this technique to get a zenair soob running while > >setting up the carb. It was way too rich and fouled the > >plugs bad. We were only ground running so did not want to ruin > >more than one set of plugs while setting the carb. > > How does fouling a plug trash it? I used to clean > and re-gap my plugs regularly . . . on old engines, > it wasn't uncommon to find one with more crud on it > than the others but 15 seconds in the plug cleaner > made it indistinguishable from the others. > > I've hear of this "trick" before but I'm at a loss > to explain it. Adding to the total spark gap length > can only raise the path resistance which makes the > event shorter in time. > > Bob . . . > ---------------------------------------------------- Sign Up for NetZero Platinum Today Only $9.95 per month! http://my.netzero.net/s/signup?r=platinum&refcd=PT97 ________________________________________________________________________________
From: "John Harlow" <jharlow(at)onearrow.net>
Subject: Re: speed reduction
Date: Mar 02, 2002
With the following information you supplied. You can use an LM317 regulator from Radio Shack to build an adjustable power supply that will provide the necessary, lower voltage for slower operation. Are you talking about MAC linear actuators? These only draw a few hundred milliamps and can be easily controlled by the smallest plastic device (LM317T). You can find data on the device along with hookup info at: http://www.national.com/ds/LM/LM117.pdf I downloaded this information, purchased the LM317T regulator and proceeded to build the speed reducer, since I only need a reduced speed I only installed a 130 ohm resistor from pin 3 to pin 2. On the bench this gave me about 10.5 volts output. The problem is that by putting this device in line it is only good for one direction as it does not work with the current flow reversed. So I just tried a 10 ohm resistor in line and it also reduced the voltage from 14.5 to around 10.5 on the bench. At this point I installed this resistor in line on my planes MAC servo and did not see and differance in acutation time. Looking for comments and Help John ________________________________________________________________________________
Date: Mar 02, 2002
Subject: Re: speed reduction
From: Denis Walsh <deniswalsh(at)earthlink.net>
I ran my servo on a 9v teeny battery during testing and I couldn't tell much difference either. So I suspect you need to be down at some lower voltage to cut speed at least in half which is what I think most folks want. My suggestion is to fly and try. I think faster is better. When I roll out on final, it is too slow. When I am at high cruise it is a little quick but easily manageable. Hence I have never fiddled with it. To me the only challenge was to learn the tenth of a second "blip" it takes to trim at cruise. On the other hand I love gadgets, and someday may put a two position micro switch in just so my guest pilots can play with it. DLW > From: "John Harlow" <jharlow(at)onearrow.net> > Reply-To: aeroelectric-list(at)matronics.com > Date: Sat, 2 Mar 2002 19:49:05 -0500 > To: > Subject: Re: AeroElectric-List: Re: speed reduction > > > With the following information you supplied. > > You can use an LM317 regulator from Radio Shack to > build an adjustable power supply that will provide > the necessary, lower voltage for slower operation. > > Are you talking about MAC linear actuators? These > only draw a few hundred milliamps and can be > easily controlled by the smallest plastic > device (LM317T). > > You can find data on the device along with > hookup info at: > > http://www.national.com/ds/LM/LM117.pdf > > > I downloaded this information, purchased the LM317T regulator and proceeded > to build the speed reducer, since I only need a reduced speed I only > installed a 130 ohm resistor from pin 3 to pin 2. On the bench this gave me > about 10.5 volts output. The problem is that by putting this device in line > it is only good for one direction as it does not work with the current flow > reversed. So I just tried a 10 ohm resistor in line and it also reduced the > voltage from 14.5 to around 10.5 on the bench. At this point I installed > this resistor in line on my planes MAC servo and did not see and differance > in acutation time. > Looking for comments and Help > John > > > > > > ________________________________________________________________________________
From: "Richard D. Fogerson" <rickf(at)velocitus.net>
Subject: Re: I need help in selecting electrical system
Date: Mar 02, 2002
The rational is then: Even if you lose your only alternator, you shut down the main bus and maintain the essential bus, and still operate the 2 EI's, radio, xpdr, and RMI encoder (flt instruments) off the well maintained and/or tested 17 ah battery. It should get you at least 2 to 3 hrs flying time. And, if one really wanted a little more insurance, you could install a small aux battery to run the EI's but probably not necessary. Does that about cover it? One other point, Jeff Rose says there is a brief 8 amp surge for each EI when first turned on, should the fuse be increased from 3 to 10 amps and the wire from 20 to 16 AWG? Thanks, Bob Rick Fogerson > >Bob, > >Some further clarification, the GPS I'm leaning toward is the Skymap II from > >Bendix King that is charged by the aircraft electrical system but has NiCad > >battery backup so it is not a problem. However, I want to use the Microair > >comm and xpdr (don't like handhelds) and I forgot to mention that the > >alternator/regulator will be B&C but the starter will have to be Skytech > >(for unrelated reasons). > > > >Does this change your recommendation to something else? > > Yes. New battery every two years max . . . or every > annual just for the hell of it. If you don't mind > running a capacity check every 6 months or so after > the first year, then keep the battery until it drops > below 4 hours sustained e-bus loads. > > Bob . . . > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: KITFOXZ(at)aol.com
Date: Mar 02, 2002
Subject: Re: spark ign. question
"All other things being constant and irrespective of whether the system is inductive or capacitive storage, adding a spark gap in series with the gap in the plug would simply allow a fixed amount of energy to be dissipated in two places instead of one.=A0 I'm having trouble figuring out how adding the second gap outside the cylinder improves performance for the gap inside. =A0 Bob" I have always known that a wet/fouled plug will sometimes begin to fire as you pull off the wire a little to open up an additional gap at the plug cap. Is it possible that a wet/fouled plug is more likely to just short out the current up inside the electrode of the plug when the applied voltage is great, but when you reduce the voltage a little, it will jump the gap at the tip instead? John Z. ________________________________________________________________________________
Date: Mar 03, 2002
From: Robert McCallum <robert.mccallum2(at)sympatico.ca>
Subject: Re: spark ign. question
Your physics books are no doubt correct, but those formulas are based on a specific voltage, a specific inductance, a specific capacitance etc. all constant values. That's just the point, all other things are not constant and the amount of energy available is not fixed. The voltage in an ignition system rises to the point where it "jumps the gap" at which point it is effectively shorted to ground and the energy stops building and is dissipated. The voltage is not constant if you change the spark gap therefore the charge is not constant and therefore the energy is not constant. The larger gap requires the voltage to build to a higher value before it "jumps the gap" making more energy available. In some automotive electronic ignition systems which are capable of generating 50 to 60,000 volts but only "normally" require 12 to 15,000 to fire the plugs there are warnings not to run the engine with plug wires removed because without the proper discharge gap in the circuit you can build voltages sufficient to breakdown the insulation in the coil and/or plug wires. Larger gap equates to higher available voltage which equates to higher available energy. If you can convince this energy to find it's way into your cylinder at the right time it "may" fire that fouled or worn plug. The extra gap has been proven to work by many people. Sometimes accidentally and sometimes intentionally as in "booster gap" spark plugs which do seem to fire mixtures that ordinary plugs won't with no other changes to the ignition system. All of the above explains (??? maybe) why modern cars run larger spark gaps to create hotter sparks (more energy) to help burn the fuel more completely to reduce emissions. Reducing the spark gap results in a demonstrably lower voltage at the plug, less efficient combustion and greater emissions without making any other changes. Bob McC "Robert L. Nuckolls, III" wrote: > > Hmmm . . . my physics book says energy stored on a capacitor > is joules (watt seconds) = volts squared times capacitance > divided by 2. Hence a 100 uF capacitor charged to > 300 volts stores 4.5 joules of energy. An inductor's > storage is amps squared times inductance divided by > two . . . If memory serves me correctly, my ol' Chevy > spark coil primary was about 10 millihenries charged > to 2A for a potential energy storage of 20 millijoules. > When we rewound them for transistor ignition, we'd > pull off the primary and wind it back on with half the > turns and double the wire. Half turns gave us 2.5 > millihenries of inductance but we would charge it with > about 10 amps for a storage of 125 millijoules of > energy. > > All other things being constant and irrespective > of whether the system is inductive or capacitive > storage, adding a spark gap in series with the > gap in the plug would simply allow a fixed > amount of energy to be dissipated in two places > instead of one. I'm having trouble figuring out > how adding the second gap outside the cylinder > improves performance for the gap inside. > > Bob . . . > ________________________________________________________________________________
From: "Tom Barnes" <skytop(at)megsinet.net>
Subject: Pin numbers of S700-2-10 on Z-23 & Z-24
Date: Mar 02, 2002
Bob, Regarding figures Z-23 and Z-24, is there a typo on the pin numbers for the S700-2-10 switch? I looked through the archives and couldn't find any mention of errors, so if it's correct, please explain what's different that reverses the pin 2 and pin 5 logic between these drawings and Z-13. Thanks, Tom Barnes ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: spark ign. question
> >Bob, in a distributor-less system it may make sense that the fouled plug >may load down the >coil so it's never allowed to build up to full voltage. If you create an >extra gap, it will >build up to full voltage and probably result in a higher voltage across >the fouled plug. I guess I'm having trouble defining fouled. Are we talking about contamination that bridges the plug's gap? Or just a lot of crud that coats things but leaves some smaller gap? If the gap is filled, then it seems the task is to put enough energy into the offending material to burn it away. If we're talking about jumping a smaller gap, then it seems the task is still to put enough energy into the now shorter spark to get the fuel-air mixture to ignite anyhow. The later case seems the easiest . . . if the gap is completely filled, then the plug is effectively shorted and the energy required to clear it has to be several orders of magnitude greater than what it takes to simply generate a spark. For a given pressure, mix of gasses and availability of sharp edges to induce sparking at the lowest possible voltage, then we could expect a plug to take more voltage to produce a useful spark in the first place . . . but with a reduced gap, the sustaining voltage may be lower than for a wider, clean gap. An inductive coil storage ignition system tends to deliver energy in a constant current mode . . . so once a spark establishes across a reduced quality gap, the low sustaining voltage times the constant current results in less energy delivered to combustible gasses. I'm trying to figure out the physics that says if we provide an external spark gap (which takes voltage to ionize and energy to sustain) that the energy for the internal spark gaps goes up as a result. Not seeing how that works just yet. Bob. . . ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Alternator B-lead fuse question
> >The one I have appears to be wired with no 8 wire. >This said, is it OK? If it is indeed #8 you could go up to 50A alternator. Have you counted the strands of wire and measured one of them with a micrometer? Or . . . is it marked 8AWG? Where did you find this product? >Discussing this, I also saw another in-line fuse >holder which supports large tubular fuses. It is a >heavy plastic two-parts tube in which you insert the >fuse and you screw one part into the other. That was >the first time I saw one for big fuses like that >(about 1/4" or 5/16" in diameter). The wire with that >one is definitively a no 8 as it is written on it >(with a PVC jacket). Would this be good? The automotive super-audio guys have a whole line of fuseholders that mount and wire large glass cartridge fuses. The ones I've seen depend on tension set up in the threaded end caps of a plastic housing to capture the fuse inside. Just not the makings for long-life, gas-tight joints. Also, the ones I saw use setscrews to attach wires to the conductive end caps. Okay for audio systems in cars and wiring up junction boxes for houses but not practiced in airplanes anywhere I've seen. Bob . . . ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: I need help in selecting electrical
system > > >The rational is then: Even if you lose your only alternator, you shut down >the main bus and maintain the essential bus, and still operate the 2 EI's, >radio, xpdr, and RMI encoder (flt instruments) off the well maintained >and/or tested 17 ah battery. It should get you at least 2 to 3 hrs flying >time. exactly >And, if one really wanted a little more insurance, you could install a small >aux battery to run the EI's but probably not necessary. Does that about >cover it? I think so >One other point, Jeff Rose says there is a brief 8 amp surge for each EI >when first turned on, should the fuse be increased from 3 to 10 amps and the >wire from 20 to 16 AWG? no . . . 20AWG wire takes hundreds of amps for several seconds to burn it. If you find that the inrush is popping the 3A fuse, then with 20AWG you can upsize it to 7A . . . but I don't think the 3A fuse is going to give you any problems. Are you planning a vacuum system? Bob . . . ________________________________________________________________________________
From: DanJE(at)aol.com
Date: Mar 03, 2002
Subject: Laptop power in the cockpit
Bob: This is probably a question you've answered before... but I can't read all the messages here! Needed: Power for my laptop in the cockpit. While flying from Kona to SFO today, I found my new HP Pavilion (N5420) laptop lithium battery is good for less than 45 minutes. Its a new computer, so this is really disappointing. Getting down on my hands and knees, I found the typical Boeing outlets.. one labeled 28VDC and the other 115VAC. Now.. from past experience I'm darn sure that 115VAC is 400 HZ, and I'm guessing it will fry the 115v adapter that came with the computer. That adapter says its smart enough to handle and convert 100-240 volts, 50-60 HZ. Out put is 19vDC, 3.16 amps. I'd guess my computer could survive on most any DC input of perhaps 12v to 20 volts, but I'm not so sure it could handle 28V DC. The airline used to provide first class and business class (I dunno, maybe coach, too?) with 15 volt power outlets, but has recently deactivated all of them. Something about they had a spark or a fire in some plane.. Poor passengers that appear with the appropriate cords, cables, etc that they bought thinking we'd give them 15 volts at their seats! Nonetheless, I go back and see folks still using their laptops on battery power 8 to 12 hours into a flight! I don't know how they do this! Two questions: Where can I buy a plug that will plug into that 28VDC outlet in the typical Boeing cockpit? It looks like a round receptacle, about 1.2 inches in diameter, with one prong vertical and the other semi-circular opposite the straight one. It looks like this: | ) with a circle around it. I guess the idea is to keep someone from plugging a normal 110vac plug into it by mistake. Second question: Without knowing how many amps my computer draws, how can I select a resistor to step down the voltage from 28vDC to about 15 -19 volts DC so my computer can handle it? Is there an easy way to step down 28 v DC to 15-19 vDC with some simple circuitry, without knowing how much current (or how much resistance) the using component will draw or offer? I'm not so sure a laptop will operate on 12 volts, but perhaps it could. In that case, I was contemplating one of the devices sold to step down aircraft 28 volt systems to 12 volts for use with 12 volt avioncis and radios. Would that be wise? Dan Eikleberry Las Vegas ________________________________________________________________________________
Date: Mar 03, 2002
From: Michel Therrien <mtherr(at)yahoo.com>
Subject: Re: Alternator B-lead fuse question
--- "Robert L. Nuckolls, III" > Have you counted the strands of wire and measured > one of them with a micrometer? Or . . . is it > marked > 8AWG? It is not marked. It must have hundreds of tiny strands and it has a vinyl insulation. It fits a no 8 butt splice just well and with insulation removed it appears to be the same diameter as my no 8 tefzel wire (but much more flexible). The strands are not tinned. > Where did you find this product? Local electronic part surplus store. They had only a few left in a box. > >Discussing this, I also saw another in-line fuse > >holder which supports large tubular fuses. It is a > >heavy plastic two-parts tube in which you insert > the > >fuse and you screw one part into the other. That > was > >the first time I saw one for big fuses like that > >(about 1/4" or 5/16" in diameter). The wire with > that > >one is definitively a no 8 as it is written on it > >(with a PVC jacket). Would this be good? > > The automotive super-audio guys have a whole > line > of fuseholders that mount and wire large glass > cartridge fuses. The ones I've seen depend on > tension set up in the threaded end caps of a > plastic housing to capture the fuse inside. > Just not the makings for long-life, gas-tight > joints. Also, the ones I saw use setscrews to > attach wires to the conductive end caps. > Okay for audio systems in cars and wiring > up junction boxes for houses but not practiced > in airplanes anywhere I've seen. Thanks! ===== ---------------------------- Michel Therrien CH601-HD http://pages.infinit.net/mthobby http://mthobby.pcperfect.com/ch601 http://sports.yahoo.com ________________________________________________________________________________
Date: Mar 03, 2002
From: John Solecki <jsolecki(at)sympatico.ca>
Subject: Re: spark ign. question
" I guess I'm having trouble defining fouled. Are > we talking about contamination that bridges the > plug's gap? Or just a lot of crud that coats > things but leaves some smaller gap? > > Neither, the secondary gap only helps when there is liquid contamination (oil, gas, > combustion by-products) between the center electrode, insulator and outer shell (ground). > It's not the spark energy that cleans out this contamination, it's the fact that once the > cylinder starts firing the spark plug electrode temperature gets high enough to vaporize > and oxidize the liquid contaminants. > > If the gap is filled, then it seems the task > is to put enough energy into the offending > material to burn it away. If we're talking about > jumping a smaller gap, then it seems the task > is still to put enough energy into the now shorter > spark to get the fuel-air mixture to ignite > anyhow. > > The later case seems the easiest . . . if the > gap is completely filled, then the plug is effectively > shorted and the energy required to clear it has to > be several orders of magnitude greater than what > it takes to simply generate a spark. > > For a given pressure, mix of gasses and availability > of sharp edges to induce sparking at the lowest > possible voltage, then we could expect a plug > to take more voltage to produce a useful spark > in the first place . . . but with a reduced gap, > the sustaining voltage may be lower than for a > wider, clean gap. An inductive coil storage > ignition system tends to deliver energy in a constant > current mode . . . so once a spark establishes > across a reduced quality gap, the low sustaining > voltage times the constant current results in less > energy delivered to combustible gasses. > > I'm trying to figure out the physics that says > if we provide an external spark gap (which takes > voltage to ionize and energy to sustain) that > the energy for the internal spark gaps goes up > as a result. Not seeing how that works just > yet. > The resistance of the contamination is low enough that spark never reaches the ionization > voltage, but not so low that it merely shorts out and conducts the eventual spark the > secondary gap allowed. The trick is to allow the spark to reach a voltage high enough to > ionize the gap(s); then there must be enough energy in the spark pulse to deal with the two > parallel resistances--the contamination and the ionized air gap. Obviously if the > contamination resistance is too low or the total spark energy too low then a spark of > enough energy to ignite the charge will not occur. John Toronto, Canada > > ________________________________________________________________________________
From: jerry(at)tr2.com
Subject: Re: spark ign. question
Date: Mar 03, 2002
Robert L. Nuckolls, III wrote: > > I'm trying to figure out the physics that says > if we provide an external spark gap (which takes > voltage to ionize and energy to sustain) that > the energy for the internal spark gaps goes up > as a result. Not seeing how that works just > yet. > *** How about this: The crud across the plug is not a short - it is a resistor. This resistor kills the Q of the spark coil, so the voltage never builds properly. The extra gap keeps the resistor off the spark coil until the voltage has already built. I *have* seen this effect - fouled cylinder, not firing. Pull the wire off the distributor, make a big zappy spark - cylinder fires! WRT the gap eating energy: the Kettering ignition system AFAIK, behaves like a current source. I've seen it on an ignition scope: disconnect the plug, voltage rises to 50-60kV. A spark gap OTOH acts like a voltage regulator ( VR ) tube. It's VR value depends on the width of the gap AND on the material filling the gap. The higher the gas pressure, the greater the voltage. Stomp on the gas, the voltage goes up - because the cylinder pressures go up, the VR value goes up, and the current source raises its output voltage. This is also why a marginal ignition system will idle fine, and hiccup when you drive up a hill. At idle, the plugs are regulating the output of the ignition system to a low voltage, and everything works. You stomp on the gas, the cylinder compression rises, the ignition voltage rises, the voltage goes up, and _ZAP_ something shorts out, maybe a carbon track on the distributor cap. Stumble! SO: As long as the sum of the plug voltage and gap voltage is smaller than the compliance of the rest of the ignition, the plug will fire. HOWEVER: this is hard on the coil and distributor, since higher voltages are impressed on them. - Jerry Kaidor ( jerry(at)tr2.com ) ________________________________________________________________________________
From: "Gary Casey" <glcasey(at)gte.net>
Subject: Plug fouling
Date: Mar 03, 2002
<> Maybe I can add something to this. I think you've simplified the explanation a little bit too much. Yes, a "fouled" plug is one in which deposits on the insulator become conductive and offer a parallel path for the current to ground. The spark is made in a "Kettering" ignition system by building up current in a coil and then interrupting the current. A coil has inductance, which means that it doesn't like to change current. Interrupting the current causes the voltage across the secondary terminals to rise, but not instantaneously (I know, I'm guilty of over-simplifying as well). As the voltage at the spark plug rises the current can flow through the parallel resistance path essentially bleeding energy from the coil before it has a chance to reach the voltage required to jump the gap and no spark will occur. It's not a "weak" spark that prevents ignition, it is no spark. If some cylinders can fire and start the engine the magneto will be spun faster, creating more energy and maybe be able to overcome the fouling. Granted, there is a fine line where there is just enough energy in the coil to jump the gap, but not enough to sustain the arc and in that case it may light a fire and may not - it depends on how close to correct the air/fuel ratio is right at the gap. Gary Casey ________________________________________________________________________________
From: "Miles McCallum" <milesm(at)avnet.co.uk>
Subject: Re: spark ign. question
Date: Mar 03, 2002
> All of the above explains (??? maybe) why modern cars run larger spark gaps to create hotter sparks > (more energy) to help burn the fuel more completely to reduce emissions. Reducing the spark gap > results in a demonstrably lower voltage at the plug, less efficient combustion and greater emissions > without making any other changes. > > Bob McC Interesting... A few years ago I ran a 728i BMW beater ($600 bought me 5 years and 200,000 miles) and other than oil changes, I rarely did anything to it, but I did log mileage/fuel. At about 75,000 miles after I bought it, (190,000 on the clock) it developed a high speed misfire - last 10% of the rpm: the problem turned out to be the plugs - the side electrodes had all but gone, and the center electrode had eroded below the insulator..... (I still have one of the plugs!) - putting a new set in cured the misfire, but changed the fuel consumption from 16.1 (imp) mpg to 15.7 mpg. I now drive a diesel - not as fast, doesn't handle as well, but averages 47mpg and you can get wing struts inside. If you want to know why, calculate 200,000 miles @ 16 mpg X about $3.50 gallon.... Miles McC ________________________________________________________________________________
From: "Tom Barnes" <skytop(at)megsinet.net>
Subject: Wig-wag with only landing lights
Date: Mar 03, 2002
Bob, I do not plan to use taxi light(s) on my (tail wheel) RV-6, so my panel is designed for a single switch (OFF-FLASH-LANDING). Following the recent thread about the Gall's FS039, I ordered one. I have an S700-2-10 switch (and two Radio Shack 30A relays if necessary), planned for this function. I have downloaded the drawings from your web site regarding the wigwag but I'm can't seem to integrate what I need. I'm now questioning whether or not the 2-10 switch is suited for my application. Your comments will be appreciated. Thanks, Tom Barnes ________________________________________________________________________________
Date: Mar 03, 2002
From: Miller Robert <rmiller3(at)earthlink.net>
Subject: Re: Laptop power in the cockpit
> DanJE(at)aol.com wrote: > Nonetheless, I go back and see folks still using their laptops on battery > power 8 to 12 hours into a flight! I don't know how they do this! > > > I generally get about 5 hours from my Apple iBook battery. Robert ________________________________________________________________________________
From: George Braly <gwbraly(at)gami.com>
Subject: Re: spark ign. question
Date: Mar 03, 2002
Bob, In 1903, Sir Oliver J. Lodge and his son, Alec, patented the "spark intensifier". As I understand it, this technique is still used in some turbine engine igniters. This was studied by the Nat. Bureau of Standards during the 1920s. They developed a set of curves to show how the use of a spark intensifier gap would help overcome the failure of ignition due to electrical leakage at the spark plugs. Apparently, if the plug insulation is degraded by deposits or other crud, then the magneto may never build up enough voltage to strike the spark. Adding the external spark gap in series at a well insulated point in the circuit, causes a build up in potential (from capacitance in the insulated wiring harness?) at the gap... which "fires" and thus, also causes enough voltage to strike an arc at the plug. All of this described in the book, "Spark and Flames" a history of ignition in internal combustion engines, by Crawford MacKend. >>Hmmm . . . my physics book says energy stored on a capacitor is joules (watt seconds) = volts squared times capacitance divided by 2. Hence a 100 uF capacitor charged to 300 volts stores 4.5 joules of energy. An inductor's storage is amps squared times inductance divided by two . . . If memory serves me correctly, my ol' Chevy spark coil primary was about 10 millihenries charged to 2A for a potential energy storage of 20 millijoules. When we rewound them for transistor ignition, we'd pull off the primary and wind it back on with half the turns and double the wire. Half turns gave us 2.5 millihenries of inductance but we would charge it with about 10 amps for a storage of 125 millijoules of energy. All other things being constant and irrespective of whether the system is inductive or capacitive storage, adding a spark gap in series with the gap in the plug would simply allow a fixed amount of energy to be dissipated in two places instead of one. I'm having trouble figuring out how adding the second gap outside the cylinder improves performance for the gap inside. Bob . . .<< http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Laptop power in the cockpit
> >Bob: > This is probably a question you've answered before... but I can't read >all the messages here! > > Needed: Power for my laptop in the cockpit. > >While flying from Kona to SFO today, I found my new HP Pavilion (N5420) >laptop lithium battery is good for less than 45 minutes. Its a new computer, >so this is really disappointing. I think your battery is bad out of the box . . . I have had several Pavilions and currently use the 3410 in a variety of portable computing and data acquisition tasks. The 3410 came with a lithium battery but it's recommended replacement from HP is a Ni-MH technology. > Getting down on my hands and knees, I found the typical Boeing outlets.. >one labeled 28VDC and the other 115VAC. Now.. from past experience I'm darn >sure that 115VAC is 400 HZ, and I'm guessing it will fry the 115v adapter >that came with the computer. Many if not most line operated power supplies for laptops run the incoming AC directly into a rectifier and couldn't care less about frequency. Also, if the outlets are provided for passenger use with their laptops, I wouldn't bet that there isn't a separate, 115VAC, 60Hz power supply to these outlets . . . the LAST thing the airline would want is a story about having trashed a bunch of first-class passenger's toys. > That adapter says its smart enough to handle >and convert 100-240 volts, 50-60 HZ. Out put is 19vDC, 3.16 amps. I'd guess >my computer could survive on most any DC input of perhaps 12v to 20 volts, >but I'm not so sure it could handle 28V DC. > >The airline used to provide first class and business class (I dunno, maybe >coach, too?) with 15 volt power outlets, but has recently deactivated all of >them. Something about they had a spark or a fire in some plane.. Poor >passengers that appear with the appropriate cords, cables, etc that they >bought thinking we'd give them 15 volts at their seats! >Nonetheless, I go back and see folks still using their laptops on battery >power 8 to 12 hours into a flight! I don't know how they do this! Look into a Ni-Mh drop-in replacement. If your computer is new, they might give you this battery on warranty . . . 45 min service life is useless. For use on airplanes, I have a 28v to 19 volt step-down regulator built on one of our linear dimmer frames. For 14 volt aircraft, I use a switch-mode step-up power supply to give me the 19 volts from the aircraft power. Bob . . . >Two questions: Where can I buy a plug that will plug into that 28VDC >outlet in the typical Boeing cockpit? It looks like a round receptacle, >about 1.2 inches in diameter, with one prong vertical and the other >semi-circular opposite the straight one. It looks like this: | ) with a >circle around it. I guess the idea is to keep someone from plugging a normal >110vac plug into it by mistake. Couldn't tell you without seeing it. > Second question: Without knowing how many amps my computer draws, how > can I >select a resistor to step down the voltage from 28vDC to about 15 -19 volts >DC so my computer can handle it? Is there an easy way to step down 28 v DC >to 15-19 vDC with some simple circuitry, without knowing how much current (or >how much resistance) the using component will draw or offer? Resistors are a bad idea but a regulator with some smarts like http://209.134.106.21/temp/apc15-14a.jpg http://209.134.106.21/temp/apc15-14b.jpg http://209.134.106.21/temp/apc15-14c.jpg would do the job . . . or you can use switch-mode step down regulator that would dissipate less heat and probably be a bit smaller. > I'm not so sure a laptop will operate on 12 volts, but perhaps it >could. In that case, I was contemplating one of the devices sold to step down >aircraft 28 volt systems to 12 volts for use with 12 volt avioncis and >radios. Would that be wise? I've had some 19v rated laptops run on 12 but they wouldn't charge the on-board battery when supplied with 12v . . . suggest one of our power conditioners or a switch-mode step-down tailored to your task. Bob . . . >Dan Eikleberry >Las Vegas > > Bob . . . -------------------------- TEMPORARY WEBSITE ADDRESS: http://209.134.106.21 -------------------------- ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Alternator B-lead fuse question
> > >--- "Robert L. Nuckolls, III" > > Have you counted the strands of wire and measured > > one of them with a micrometer? Or . . . is it > > marked > > 8AWG? > >It is not marked. It must have hundreds of tiny >strands and it has a vinyl insulation. It fits a no 8 >butt splice just well and with insulation removed it >appears to be the same diameter as my no 8 tefzel wire >(but much more flexible). The strands are not tinned. > > > Where did you find this product? > >Local electronic part surplus store. They had only a >few left in a box. Interesting! Sounds like a cut above the auto-parts- store products. Any brand name on it? If it was a surplus store, they'll have no idea as to orignal source. Wouldn't mind having one to look at and evaluate for suitability. Perhaps I can track down the folks who make it. Bob . . . ________________________________________________________________________________
From: "Joe Larson" <jpl(at)showpage.org>
Subject: Re: AeroElectric-List Digest: 26 Msgs - 03/02/02
Date: Mar 03, 2002
> From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com> > I'm trying to figure out the physics that says > if we provide an external spark gap (which takes > voltage to ionize and energy to sustain) that > the energy for the internal spark gaps goes up > as a result. Not seeing how that works just > yet. Time to display ignorance again. Could the extra gap outside cause the spark to occur delayed -- and possibly delayed just enough to actually happen at a better time for the engine to actually get running? No clue how much longer it would take for a spark to occur, but it's just a thought. I could easily see this with a lawn mower -- where the mower doesn't have a delayed spark system like we have when we start our airplane engines. Normally the spark fires something short of top dead center. But when starting, we want the start to occur after TDC by some amount. -Joe ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Electrical System Instrumentation
> >Hi Bob, > >I am putting together a Murphy Super Rebel and am a month or so away from >starting the Engine Installation/ Panel and Wiring. The majority of the >panel goodies have been selected and on hand. I am trying to wrap up >instrumentation for the 9 cyl 400 HP M-14PF Radial. >My question for you concerns instrumentation for the electrical system of >the SR. > >I know I want a digital voltmeter and I would like it to be a 2.25 round. >Both Electronics International and Davtron make such an animal and both can >be toggled between Volts and Amps. A Davtron Model, the M475VAA has dual >shunts and can read voltage and two current flows. It can measure alternator >output and charge and discharge of the battery. It has a three position >toggle switch. Volts/ +,- Battery Amps/Alternator amps. I highly recommend external shunt ammeters for two reasons (1) they keep high current leads out of the cockpit and (2) they can be used to monitor more than one current by means of an ammeter selector switch and multiple shunts. I'd go with the Davtron but put the shunts in each of the two alternator output leads . . . if you have a good voltmeter then a battery ammeter is less than useful compared to the pair of alternator loadmeter functions. Bob . . . ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Microair radio & xpdr amp
requirements > > > > > > > I'll be > > > offering a kit of transponder, prewired harness and > > > ACK encoder for a package price. > > > > > > Bob . . . > >...and if you could sweeten the deal even more by (figuratively!) tossing >in the com >radio, harness, antenna & maybe even an intercom, I'll seriously consider >sending ya >a check- plug&play- yeah, that's the ticket! I'll work on it. Eagerly awaiting arrival of the first units. Bob . . . ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Wig-wag with only landing lights
> >Bob, > I do not plan to use taxi light(s) on my (tail wheel) RV-6, >so my panel is designed for a single switch (OFF-FLASH-LANDING). >Following the recent thread about the Gall's FS039, I ordered one. I >have an S700-2-10 switch (and two Radio Shack 30A relays if necessary), >planned for this function. I have downloaded the drawings from your >web site regarding the wigwag but I'm can't seem to integrate what I >need. I'm now questioning whether or not the 2-10 switch is suited for >my application. Your comments will be appreciated. I didn't like the FS039 because it had a switch on the front. That's why my published drawings show the FS033. If I were going to use a Galls wig-wag I'd use the 033 and wire it per http://209.134.106.21/articles/gallsww.pdf . . . I've got the 039 in hand and will see if I can deduce a way to use it but I don't recommend it. If you're going to have two lights, are both on for landing? Bob . . . ________________________________________________________________________________
Date: Mar 03, 2002
From: Dennis Golden <dgolden@golden-consulting.com>
Subject: Re: spark ign. question
"Robert L. Nuckolls, III" wrote: > > > > > > > >True, but the higher resistance means the energy has to build to a higher > >level before it jumps the > >gap. This greater energy being dissipated across the plug gap creates a > >hotter spark although as you > >state the duration of the spark may be shorter. If the fire starts within > >this time frame you're > >away. If not, then the "trick" didn't work this time, but it often does. > >If you think of an > >ignition coil (or Mag) as being similar to a large capacitor charging up > >until the energy is > >released by the fact that the voltage built high enough to jump a spark > >gap, then the larger the gap > >the more energy is stored before the spark jumps and the more energy is > >released in the resultant > >spark > > Hmmm . . . my physics book says energy stored on a capacitor > is joules (watt seconds) = volts squared times capacitance > divided by 2. Hence a 100 uF capacitor charged to > 300 volts stores 4.5 joules of energy. An inductor's > storage is amps squared times inductance divided by > two . . . If memory serves me correctly, my ol' Chevy > spark coil primary was about 10 millihenries charged > to 2A for a potential energy storage of 20 millijoules. > When we rewound them for transistor ignition, we'd > pull off the primary and wind it back on with half the > turns and double the wire. Half turns gave us 2.5 > millihenries of inductance but we would charge it with > about 10 amps for a storage of 125 millijoules of > energy. > > All other things being constant and irrespective > of whether the system is inductive or capacitive > storage, adding a spark gap in series with the > gap in the plug would simply allow a fixed > amount of energy to be dissipated in two places > instead of one. I'm having trouble figuring out > how adding the second gap outside the cylinder > improves performance for the gap inside. > I'm no electrical engineer; however, I believe that if a spark plug is wet or fouled, there is a relatively low resistance path through the contaminants if the voltage buildup is slow. By having an outside gap, when the spark crosses the gap, it builds much faster than directly from the coil. This is one of the reasons that the capacitive discharge conversions would usually out perform the ketering (SP?) counterpart. It just has less time to flow through the contaminants. Regards, Dennis -- Dennis Golden Golden Consulting Services, Inc. ________________________________________________________________________________
Date: Mar 03, 2002
From: Michel Therrien <mtherr(at)yahoo.com>
Subject: Re: Alternator B-lead fuse question
No brand name, not even a logo. I'm gonna send you the one I have... To which one of your three addresses do I ship? --- "Robert L. Nuckolls, III" wrote: > Nuckolls, III" > > Therrien > > > > > >--- "Robert L. Nuckolls, III" > > > > Have you counted the strands of wire and > measured > > > one of them with a micrometer? Or . . . is it > > > marked > > > 8AWG? > > > >It is not marked. It must have hundreds of tiny > >strands and it has a vinyl insulation. It fits a > no 8 > >butt splice just well and with insulation removed > it > >appears to be the same diameter as my no 8 tefzel > wire > >(but much more flexible). The strands are not > tinned. > > > > > Where did you find this product? > > > >Local electronic part surplus store. They had only > a > >few left in a box. > > Interesting! Sounds like a cut above the > auto-parts- > store products. Any brand name on it? If it was > a > surplus store, they'll have no idea as to orignal > source. Wouldn't mind having one to look at and > evaluate for suitability. Perhaps I can track > down > the folks who make it. > > Bob . . . > > > > Forum - > Contributions of > any other form > > latest messages. > other List members. > > aeroelectric-list(at)matronics.com > http://www.matronics.com/subscription > http://www.matronics.com/photoshare > http://www.matronics.com/browselist/aeroelectric-list > http://www.matronics.com/search > http://www.matronics.com/archives > http://www.matronics.com/emaillists > > > > > ===== ---------------------------- Michel Therrien CH601-HD http://pages.infinit.net/mthobby http://mthobby.pcperfect.com/ch601 http://sports.yahoo.com ________________________________________________________________________________
Date: Mar 02, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: spark ign. question
>Only thing I figure is that spark plugs that worked in my 7.6 to 1 >compression ratio Ford 6 wouldn't fire under the higher pressures in the >10.5 to 1 V-8. Subsequent life experience confirmed that higher compression >requires better/different plugs than what will work in a low compression >engine. I recall my friendly local service station had a spark plug cleaning and testing bench. One first cleaned the plug with compressed air driven blasting compound. He then screws the plug into a chamber with a window in it so you can see the spark gap. A Ford buzzer-coil type ignition was attached to the plug to spark it while pressure in the chamber was raised with shop air. A plug that wouldn't fire at less than 120 psi was rejected. >Cleaning? I used to clean my plugs in the Ford, and later, a VW, at 10,000 >miles, then replace at 20,000. Cleaning at 20,000 didn't help them work >correctly. What deteriorates? Not visible to the naked eye. Must be >"spark plug black magic" - until there's some "physics" involved. No magic. Look the center electrode of a new plug and you'll see that its crown is sharp edged and flat. A worn plug is rounded off and has no sharp edges. Sparks like to jump from sharp edges. One could restore sharp edges on both the center and ground electrodes with suitable tools but the "remanufactured" plug was shorter and therefore ran cooler than factory new specs. When I was a kid, you could buy "remanufactured" plugs for about 1/3rd the cost of new. Close examination would show that they were simply cleaned and re-sharpened. Bob . . . ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: speed reduction
> >I downloaded this information, purchased the LM317T regulator and proceeded >to build the speed reducer, since I only need a reduced speed I only >installed a 130 ohm resistor from pin 3 to pin 2. On the bench this gave me >about 10.5 volts output. The problem is that by putting this device in line >it is only good for one direction as it does not work with the current flow >reversed. So I just tried a 10 ohm resistor in line and it also reduced the >voltage from 14.5 to around 10.5 on the bench. At this point I installed >this resistor in line on my planes MAC servo and did not see and differance >in acutation time. Reversing the motor requires that you reverse it's leadwires. One lead is + extend, the other is + retract. Regulation of voltage for the purpose of controlling speed needs to be done before the switch that controls direction, i.e. your speed control needs to look like a bus having some reduced voltage . . . it goes in the line between the aircraft bus and the trim switch. If 10 ohms of resistance produces a 3.0 volt drop, then your motor is drawing 0.3 amps or 300 milliamps. Motors used in most actuators are permanent magnet devices who's speed is roughly proportional to applied voltage. The motor has no way of knowing if the voltage is reduced via resistor or adjustable regulator. With the regulator, the voltage is constant irrespective of motor current (changes with load on the actuator). With a simple series resistor speed control, the speed regulation with motor load is poor because as the motor slows due to increasing load, the current goes up. Voltage drop increases across the fixed resistor causing the motor to slow down still more. ran my servo on a 9v teeny battery during testing and I couldn't tell much difference either. So I suspect you need to be down at some lower voltage to cut speed at least in half which is what I think most folks want. My suggestion is to fly and try. I think faster is better. When I roll out on final, it is too slow. When I am at high cruise it is a little quick but easily manageable. Hence I have never fiddled with it. To me the only challenge was to learn the tenth of a second "blip" it takes to trim at cruise. On the other hand I love gadgets, and someday may put a two position micro switch in just so my guest pilots can play with it. Control of trim speed is a common problem on a lot of airplanes. The wider the speed range btween cruise and approach to landing, the worse the problem. You want runaway speeds to be limited in cruise so you deliberately reduce motor supply voltage until trim action is so benign that the pilot can perceive and react to it fast enough to prevent problems. This makes for a system that runs too slow during the approach phase. To the best of my knowledge I designed the first tightly regulated trim speed controllers for bizjets that first flew on the Lear Model 55 prototype about 1980. The system had two speeds, one about 4 times faster than the other for use in takeoff/approach and cruise phases of flight. Our soon to be offered Adjustable Power Conditioners were fitted with two potentiometers so that one might have independently controlled high and low speed settings. The transfer from low to high speed operation might be controlled by a microswitch on the flaps that select low speed operation when flaps are fully retracted and high speed as soon as the flaps come off the up-stop. Without knowing about this servo (therefore excusing me from any responsibility for my comments whatsoever), I'm wondering if perhaps pulse width modulation is the proper way to slow this guy down? Pulse width modulation is just another item in the bag of tricks that allows the motor speed to be controlled with a switch that is duty cycle switched (that's how I did it on the Lear). The motor doesn't care. If you need only one reduced speed and motor current is stable, the a resistor might do. If you need to have a stable voltage source irrespective of motor load changes, then something like what you are building (like our APC) works better. If you want to close the loop on motor speed control and hold it very constant over wide ranges of bus voltage and motor load, then more smarts and duty cycle switching is attractive. The trim actuator won't care which one you use. Bob . . . ________________________________________________________________________________
Date: Mar 03, 2002
From: Gary Liming <gary(at)liming.org>
Subject: Re: Electrical System Instrumentation
Bob, > I highly recommend external shunt ammeters for two reasons (1) they keep high current leads out of the cockpit and (2) they can be used > to monitor more than one current by means of an ammeter selector > switch and multiple shunts. What about those ammeters that use a "current sense" transducer - the ones that look like a donut that you pass the main cable through and the current is measured indirectly via the induced magnetic field - do you have any experience with those? Thanks, Gary Liming ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: RE: Ignition -
> > > Bob, > > In 1903, Sir Oliver J. Lodge and his son, Alec, patented the "spark >intensifier". > > As I understand it, this technique is still used in some turbine >engine igniters. > > This was studied by the Nat. Bureau of Standards during the 1920s. >They developed a set of curves to show how the use of a spark intensifier >gap would help overcome the failure of ignition due to electrical leakage at >the spark plugs. > > Apparently, if the plug insulation is degraded by deposits or other >crud, then the magneto may never build up enough voltage to strike the >spark. Adding the external spark gap in series at a well insulated point in >the circuit, causes a build up in potential (from capacitance in the >insulated wiring harness?) at the gap... which "fires" and thus, also causes >enough voltage to strike an arc at the plug. > > All of this described in the book, "Spark and Flames" a history >of ignition in internal combustion engines, by Crawford MacKend. Checked our local library online catalogs and couldn't come up with a copy. Wasn't this the pre-cursor to the Bendix Shower of Sparks system popular on some of bigger engines? What have you been up to George? Haven't heard from you in many a moon . . . Bob . . . ________________________________________________________________________________
From: "William Bernard" <billbernard(at)worldnet.att.net>
\"Leo Dougherty\""
Subject: Audio Flight Avionics
Date: Mar 03, 2002
Does anyone have any information about the Canadian company Audio Flight Avionics and its product the AV-10? I have a friend with one of these in a Glasstar. The unit worked well until about a month ago when at least one chip went up in smoke, literally. A replacement chip was found and installed and the unit came back to life, but the parameters are way off. (Cylinder Head Temp is 1450 degrees sitting in the hangar with the engine off and snow blowing around outside.) The company is apparently no longer in existence, and to make it worse, the identification has been ground off of all the chips except the one from which the smoke escaped. If there was some way to contact the maker, or to obtain service instructions, or a detailed description of the parts used, the unit might be salvageable. Any help would be appreciated. Thanks in advance ________________________________________________________________________________
From: George Braly <gwbraly(at)gami.com>
Subject: RE: Ignition -
Date: Mar 03, 2002
Tyndar press. Whatever that is. Lib of Congress number 97-90492. I don't think it really has much to do with the shower of sparks. And it doesn't appear to have much use except as a novelty and in the noted area of the jet engine igniter. Also, I suspect a dual gap system would be a real joy in the RF noise area!!! * * * * * * * I've been busy... see www.engineteststand.com Very much like your mail list page. You do good work! ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Pin numbers of S700-2-10 on Z-23 & Z-24
> >Bob, > Regarding figures Z-23 and Z-24, is there a typo on the pin numbers >for the S700-2-10 switch? I looked through the archives and couldn't >find any mention of errors, so if it's correct, please explain what's >different that reverses the pin 2 and pin 5 logic between these drawings Good eye. I thought I'd caught all those. Numbering shown in figures Z-23 and Z-24 are incorrect. I got wrapped around a manufacturing differences axle a few years ago when I discovered that my S700-2-10 switches were assembled opposite the Microswitch equivalents. Note the view of switch in Figure 11-11 versus switch view in Z-16. The columns are switched. Figure 11-11 is Microswitch; figure Z-16 is S700-2-10. I had published some variations on switch terminal numbering based on switches I was holding in my hand at the time not realizing there were two configurations. Sooooo . . . you've found a couple of artifacts in my wiring symbols that represent confusing times. I determined that the schematics could be left constant with respect to terminal numbers if I simply pointed out the difference between the two switches. I illustrated the S700-2-10 right on the drawing. The Microswitch product has reversed column numbers molded into the plastic switch housing. I've marked the switches in Figures Z-23/24 for correction. Thanks! Bob . . . ________________________________________________________________________________
From: "Tom Barnes" <skytop(at)megsinet.net>
Subject: Wig-wag with only landing lights
Date: Mar 03, 2002
Bob, Regarding whether one or two lights are lit for landing, without any other input, I suppose my answer would be to use two lights. Is there something to be gained by using just one? I have cut only one wing for the light at this point. If it wasn't for the fact that my panel has been engraved for the "FLASH", I'd consider just the one light but now, the panel plus the safety issue of the wigwag, I prefer to cut the other hole and have two lights. What are your thoughts? Thanks, Tom -----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: Wig-wag with only landing lights > >Bob, > I do not plan to use taxi light(s) on my (tail wheel) RV-6, >so my panel is designed for a single switch (OFF-FLASH-LANDING). >Following the recent thread about the Gall's FS039, I ordered one. I >have an S700-2-10 switch (and two Radio Shack 30A relays if necessary), >planned for this function. I have downloaded the drawings from your >web site regarding the wigwag but I'm can't seem to integrate what I >need. I'm now questioning whether or not the 2-10 switch is suited for >my application. Your comments will be appreciated. I didn't like the FS039 because it had a switch on the front. That's why my published drawings show the FS033. If I were going to use a Galls wig-wag I'd use the 033 and wire it per http://209.134.106.21/articles/gallsww.pdf . . . I've got the 039 in hand and will see if I can deduce a way to use it but I don't recommend it. If you're going to have two lights, are both on for landing? Bob . . . = = = http://www.matronics.com/browselist/aeroelectric-list = ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Alternator B-lead fuse question
> >No brand name, not even a logo. I'm gonna send you the >one I have... To which one of your three addresses do >I ship? Three? I've got only one. 6936 Bainbridge Road, Wichita, KS 67226-1008. Where did you see two others? My website front page? Those three in the yellow box are companies often mistaken for me . . . my address is in the upper right corner of the page. I appreciate your effort on this. It would be nice to identify a source for inclusion in our website catalog. I'll return the sample to you after I've had a chance to look at it. Bob . . . ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: RE: Ignition -
> >Tyndar press. Whatever that is. > >Lib of Congress number 97-90492. > >I don't think it really has much to do with the shower of sparks. > >And it doesn't appear to have much use except as a novelty and in the noted >area of the jet engine igniter. > >Also, I suspect a dual gap system would be a real joy in the RF noise >area!!! Searched for the publisher and didn't turn up anything. Could you photocopy a few pages of description and any figures that come with it? I'd like to see it. > * * * * * * * > > >I've been busy... see www.engineteststand.com Damn George, you got more expensive toys than I do! As you well know, it takes good and sometimes expensive toys to do the best work. How far is your facility from the Ada airport? >Very much like your mail list page. You do good work! Thank you sir! Bob . . . ________________________________________________________________________________
Date: Mar 03, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Electrical System Instrumentation
> >Bob, > > > > I highly recommend external shunt ammeters for two reasons (1) they > keep high current leads out of the cockpit and (2) they can be used > > to monitor more than one current by means of an ammeter selector > > switch and multiple shunts. > > >What about those ammeters that use a "current sense" transducer - the ones >that look like a donut that you pass the main cable through and the current >is measured indirectly via the induced magnetic field - do you have any >experience with those? Those are hall effect transducers. These are described in the book on page 7-15. They work fine. Rocky Mountain and others use them for current measurement. They're electronic devices with some drift and calibration issues. They're also not as rugged as a shunt. I use them routinely for flight test instrumentation where I can push a pin out of a plug, run the wire through the sensor and put the pin back in the plug. Here's a link to a company that makes several sizes that I keep handy for my quick-n-dirty instrumentation tasks: http://www.west.net/~escor/ ________________________________________________________________________________
From: George Braly <gwbraly(at)gami.com>
Subject: RE: Ignition -
Date: Mar 03, 2002
Sure, Want a fax or scanned images ? Our facility is .... ON the Ada, Airport. About 150 yards SW of the gas pumps. Two hangars -- Hangar "A" and a big WWII Quonset hangar with the Carl Goulet Memorial Engine Test Stand next to it. Come down anytime. Would love to show you around. I think you would find the engine instrumentation for the test stand to be fascinating. One can learn more about an internal combustion engine in an hour sitting there, watching the computer screen as the engine is put through its paces, than in half a lifetime doing anything else. Any time. Weekends are fine, I'm almost always here. Call ahead. Regards, George -----Original Message----- From: Robert L. Nuckolls, III [mailto:nuckolls(at)kscable.com] Subject: AeroElectric-List: RE: Ignition - > >Tyndar press. Whatever that is. > >Lib of Congress number 97-90492. > >I don't think it really has much to do with the shower of sparks. > >And it doesn't appear to have much use except as a novelty and in the noted >area of the jet engine igniter. > >Also, I suspect a dual gap system would be a real joy in the RF noise >area!!! Searched for the publisher and didn't turn up anything. Could you photocopy a few pages of description and any figures that come with it? I'd like to see it. > * * * * * * * > > >I've been busy... see www.engineteststand.com Damn George, you got more expensive toys than I do! As you well know, it takes good and sometimes expensive toys to do the best work. How far is your facility from the Ada airport? >Very much like your mail list page. You do good work! Thank you sir! Bob . . . http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
From: "Richard D. Fogerson" <rickf(at)velocitus.net>
Subject: Re: I need help in selecting electrical system
Date: Mar 03, 2002
I'm not going to have a vacuum pump. That means I could install an SD-8 Alternator right? Since you've raised the issue, assuming that's what you meant, I can't get real excited about it. Let me tell you why and you make my day and tell me where I'm wrong. It's another piece of hardware to maintain/malfunction, it has weight, and isn't cheap ($430 + $65 for ov protection). You wrote on the list on 2/24 that the SD-8 "comes with a regulator that needs a battery but it may be possible to build one that isn't". Also, "hard to controll output efficiently and power generation not efficient". I don't get a warm a feeling from that. Seems to me, if I wanted more reliability, it would be easier, cheaper, possibe? to install a second battery. Besides, did I mention I am using a B&C L-40 Alternator and regulator which is bullet proof and most likely will never fail. Where have I gone wrong? Rick Fogerson RV3 fuselage soon Boise, ID > >The rational is then: Even if you lose your only alternator, you shut down > >the main bus and maintain the essential bus, and still operate the 2 EI's, > >radio, xpdr, and RMI encoder (flt instruments) off the well maintained > >and/or tested 17 ah battery. It should get you at least 2 to 3 hrs flying > >time. > > exactly > > > >And, if one really wanted a little more insurance, you could install a small > >aux battery to run the EI's but probably not necessary. Does that about > >cover it? > > I think so > Are you planning a vacuum system? > > Bob . . . > > > > ________________________________________________________________________________
From: "Don Eaves" <doneaves(at)midsouth.rr.com>
Subject: Re: Audio Flight Avionics
Date: Mar 03, 2002
Try this email address: afatechsupport(at)home.com His name is Peter Rummell Don Eaves doneaves(at)midsouth.rr.com ----- Original Message ----- From: "William Bernard" <billbernard(at)worldnet.att.net> Subject: AeroElectric-List: Audio Flight Avionics > > > Does anyone have any information about the Canadian company Audio Flight > Avionics and its product the AV-10? > > I have a friend with one of these in a Glasstar. The unit worked well until > about a month ago when at least one chip went up in smoke, literally. A > replacement chip was found and installed and the unit came back to life, > but the parameters are way off. (Cylinder Head Temp is 1450 degrees sitting > in the hangar with the engine off and snow blowing around outside.) > > The company is apparently no longer in existence, and to make it worse, the > identification has been ground off of all the chips except the one from > which the smoke escaped. > > If there was some way to contact the maker, or to obtain service > instructions, or a detailed description of the parts used, the unit might > be salvageable. > > Any help would be appreciated. > > Thanks in advance > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Don Eaves" <doneaves(at)midsouth.rr.com>
Subject: Re: Audio Flight Avionics
Date: Mar 03, 2002
Also Try this email address: wedgie(at)interlog.com Don Eaves doneaves(at)midsouth.rr.com ----- Original Message ----- From: "William Bernard" <billbernard(at)worldnet.att.net> Subject: AeroElectric-List: Audio Flight Avionics > > > Does anyone have any information about the Canadian company Audio Flight > Avionics and its product the AV-10? > > I have a friend with one of these in a Glasstar. The unit worked well until > about a month ago when at least one chip went up in smoke, literally. A > replacement chip was found and installed and the unit came back to life, > but the parameters are way off. (Cylinder Head Temp is 1450 degrees sitting > in the hangar with the engine off and snow blowing around outside.) > > The company is apparently no longer in existence, and to make it worse, the > identification has been ground off of all the chips except the one from > which the smoke escaped. > > If there was some way to contact the maker, or to obtain service > instructions, or a detailed description of the parts used, the unit might > be salvageable. > > Any help would be appreciated. > > Thanks in advance > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Annette Coulter" <coulter(at)alaska.net>
Subject: Re: AeroElectric-List Digest: 26 Msgs - 03/02/02
Date: Mar 03, 2002
> > > I ran my servo on a 9v teeny battery during testing and I couldn't tell > > much difference either. So I suspect you need to be down at some lower > > voltage to cut speed at least in half which is what I think most > > folks want. > > > > Without knowing about this servo (therefore excusing me from any > responsibility for my comments whatsoever), I'm wondering if perhaps pulse > width modulation is the proper way to slow this guy down? > > (Yep, your parts count just went way up, too.) > > -Matt > ******************************************************* Matt - I think so to. I have been watching this thread and I suspect that lowering the voltage on a shunt dc motor just lowers the available torque - doesn't necessarily change the unloaded speed. The only speed drop one gets is from the reduced available torque. PM field dc motors look like a shunt dc motor with a fixed field voltage (also current and flux). As I recall, changing the speed on a requires a change in the field - which one can't do with a PM field. So the only way to lower the speed and keep the torque up is to use a PWM power supply. Don't hold me to this cause I have not yet done my homework and I don't deal with dc motor very often. Next week i'll be at work and will dig out some references. carl ________________________________________________________________________________
From: "Russ Werner" <russ(at)maui.net>
Subject: Re: Laptop power in the cockpit
Date: Mar 03, 2002
Bob and Dan, I have personal experience using the 115 V 400 Hz power in Boeing and Douglas airplanes. I have never seen a problem. These outlets aren't normally supplied to passengers, but the crew routinely use them to run and/or charge their various electronics including laptops. I have used it myself on 3 or 4 different computers with no ill effect. Russ Werner Maui ________________________________________________________________________________
From: "David Carter" <dcarter(at)datarecall.net>
Subject: Re: spark ign. question
Date: Mar 04, 2002
Wow, Proves it - if you are patient (wait 50 years), and ask questions and listen to others, you can eventually get answers to some of life's interesting questions. Thanks, Bob. Even though it started off talking about lawn mower engines, this has been a fun "thread". David Carter ----- Original Message ----- From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com> Subject: AeroElectric-List: Re: spark ign. question > > > > >Only thing I figure is that spark plugs that worked in my 7.6 to 1 > >compression ratio Ford 6 wouldn't fire under the higher pressures in the > >10.5 to 1 V-8. Subsequent life experience confirmed that higher compression > >requires better/different plugs than what will work in a low compression > >engine. > > I recall my friendly local service station had a spark plug > cleaning and testing bench. One first cleaned the plug with > compressed air driven blasting compound. He then screws > the plug into a chamber with a window in it so you can > see the spark gap. A Ford buzzer-coil type ignition was > attached to the plug to spark it while pressure in the > chamber was raised with shop air. A plug that wouldn't > fire at less than 120 psi was rejected. > > >Cleaning? I used to clean my plugs in the Ford, and later, a VW, at 10,000 > >miles, then replace at 20,000. Cleaning at 20,000 didn't help them work > >correctly. What deteriorates? Not visible to the naked eye. Must be > >"spark plug black magic" - until there's some "physics" involved. > > No magic. Look the center electrode of a new plug and you'll > see that its crown is sharp edged and flat. A worn plug > is rounded off and has no sharp edges. Sparks like to jump > from sharp edges. One could restore sharp edges on both > the center and ground electrodes with suitable tools but > the "remanufactured" plug was shorter and therefore ran > cooler than factory new specs. > > When I was a kid, you could buy "remanufactured" plugs > for about 1/3rd the cost of new. Close examination would > show that they were simply cleaned and re-sharpened. > > Bob . . . > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: DWENSING(at)aol.com
Date: Mar 04, 2002
Subject: Re: Where can I get
In a message dated 2/24/02 8:55:05 PM Eastern Standard Time, khorton(at)cyberus.ca writes: > I've just installed a Grand Rapids EIS 4000 engine monitor. They > provide Fast-Ons to connect the EGT and CHT thermocouples to the > wires going into the monitor. The wires to the monitor are > theromcouple wire, matching the wire coming from the thermocouples. > > Why are Fast-Ons a bad idea? Does a bit of corrosion at the > interface between the male and female Fast-Ons eventually screw up > the accuracy? > > What should be used instead of Fast-Ons? I'd like something that is > removable, so I can simply unplug rather than pulling the probes if > I ever need to pull the engine. > > Thanks, > > Kevin Horton > Bob, I guess I missed your reply to Kevin's question. Could you repeat your answer? Dale Ensing ________________________________________________________________________________
From: "gilles.thesee" <Gilles.Thesee@ac-grenoble.fr>
Subject: Guitar switch suitable for electric flaps ?
Date: Mar 04, 2002
Hi Bob and all, What would you think of the use of a 5 position lever rotary switch for our electric flaps motors ? The setups I've seen use conventionnal rotary switches and a cranked lever on the shaft to provide a positive locking effect for each flap position. Nevertheless the whole device is rather bulky behind the panel. Any advice about using a switch such as this one ? http://www.electro-nc.com/e2_m.pdf Any suggestions ? Thank you Gilles France ________________________________________________________________________________
Date: Mar 04, 2002
From: Kevin Horton <khorton(at)cyberus.ca>
Subject: relay source?
I'm looking for a source of relays similar to the S704-1 sold by on Bob's web site. See: http://www.aeroelectric.com/Catalog/switch/switch.html#s704-1 I'm looking for a couple of 12v, 4 amp relays that use Fast-On tabs. I need one that is normally open, single pole, and one that is normally closed, double pole. I've searched a few web sites, but haven't found anything similar. Can anyone point me at a vendor? Thanks, Kevin Horton RV-8 (engine installation & electrics) khorton(at)cyberus.ca (613) 821-7862 (home) Ottawa, Canada (613) 952-4319 (work) http://eccentrix.com/misc/rv8/ ________________________________________________________________________________
Date: Mar 04, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: relay source?
> >I'm looking for a source of relays similar to the S704-1 sold by on Bob's >web site. See: > >http://www.aeroelectric.com/Catalog/switch/switch.html#s704-1 > >I'm looking for a couple of 12v, 4 amp relays that use Fast-On tabs. I >need one that is normally open, single pole, and one that is normally >closed, double pole. The S704 has normally closed contact so it can be used as a normally closed. Radio Shack's 900-2394 is a similar product. I'm not aware of any double pole products in this type of package. If all you need is 4A, take a look at Radio Shack's 275-214 (4PDT - 5A) and 275-218 (DPDT - 10A) products. These may have extra poles for your task but they are easily ignored. These have tabs that can probably be wired using narrow fast-ons. I'd have to measure the tabs to be sure. Bob . . . ________________________________________________________________________________
Date: Mar 04, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: RE: Ignition -
> >Sure, > >Want a fax or scanned images ? > >Our facility is .... ON the Ada, Airport. About 150 yards SW of the gas >pumps. Two hangars -- Hangar "A" and a big WWII Quonset hangar with the >Carl Goulet Memorial Engine Test Stand next to it. > >Come down anytime. Would love to show you around. I think you would find >the engine instrumentation for the test stand to be fascinating. One can >learn more about an internal combustion engine in an hour sitting there, >watching the computer screen as the engine is put through its paces, than in >half a lifetime doing anything else. > >Any time. Weekends are fine, I'm almost always here. Call ahead. Okay. Need to get my yearly trek to George and Becki Orndorff's hangar scheduled. If I recall correctly, you're only about 35 miles off of I35. We'll drive to the seminar presentation. I've also got a flying trip to Orndorff's in the works. Either one might be an opportunity to stop by. We'll see what works. Bob . . . ________________________________________________________________________________
Date: Mar 04, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: RE: George Braly - Ignition info from book
> >Sure, > >Want a fax or scanned images ? Opps. . . forgot this in earlier post. Let's see how faxes come through. 316.685.8617 ________________________________________________________________________________
Date: Mar 04, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Guitar switch suitable for electric flaps ?
><Gilles.Thesee@ac-grenoble.fr> > > Hi Bob and all, > >What would you think of the use of a 5 position lever rotary switch for our >electric flaps motors ? >The setups I've seen use conventionnal rotary switches and a cranked lever >on the shaft to provide a positive locking effect for each flap position. >Nevertheless the whole device is rather bulky behind the panel. > >Any advice about using a switch such as this one ? > >http://www.electro-nc.com/e2_m.pdf I presume you're interested in having the switch provide input for 5 positions of flaps. Cessna did the most practical "servoed" flap control system for small aircraft. They rigged a Bowden control cable between the flap mechanism and the flap switch assembly. Microswitches that operate the flap motor are mounted on a plate that is rotated under a cam that's operated by the flap control handle. Moving the handle would depress one of the two switches which causes the flap motor to run. As the flap moves, the switch plate is moved to follow the command cam until the operated switch is released and the flaps stop. This arrangement gives you basically infinite number of flap positions although the handle is fitted with a couple or three detents. See if you can find a Cessna single engine airplane fitted with this system. A local maintenance shop should be able to show you a parts catalog and maintenance manual description of the system. The switch you've cited COULD be used as you suggest but it takes some intervening electronics to make it work. Most flap systems are so benign with respect to effect and handling qualities that the notion of more than up, half, down positions doesn't seem very useful. The nice thing about a totally manual system with a spring loaded, center off switch is that you still have infinite number of flap positions and a reliable, SIMPLE, low parts count system. Bob . . . ________________________________________________________________________________
From: "Richard D. Fogerson" <rickf(at)velocitus.net>
Subject: AFP Fuel Injection Boost Pump
Date: Mar 04, 2002
A couple of questions Bob, I was talking to AFP today and they recommend a 10 amp fuse and 20 AWG for their FI boost pump because it has a 7 amp surge at start and a 5 amp continuous power requirement. Your Z11 has 3 amp and 22 AWG. Sould I upgrade this to 7 and 20? Also, I want to put either a 3 amp CB switch or a toggle switch someplace hidden to prevent engine start, say on the line between the Battery Contactor solenoid terminal and the Battery/Alternator Master Switch. What do you think of location and switch preference? Thanks, Rick Fogerson RV3 Fuselage Boise, ID ________________________________________________________________________________
Date: Mar 04, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: motor speed control
> > > > > > > I ran my servo on a 9v teeny battery during testing and I couldn't tell > > > much difference either. So I suspect you need to be down at some lower > > > voltage to cut speed at least in half which is what I think most > > > folks want. > > > > > > > Without knowing about this servo (therefore excusing me from any > > responsibility for my comments whatsoever), I'm wondering if perhaps pulse > > width modulation is the proper way to slow this guy down? > > > > (Yep, your parts count just went way up, too.) > > > > -Matt > > >******************************************************* >Matt - > >I think so to. I have been watching this thread and I suspect that lowering >the voltage on a shunt dc motor just lowers the available torque - doesn't >necessarily change the unloaded speed. The only speed drop one gets is from >the reduced available torque. PM field dc motors look like a shunt dc motor >with a fixed field voltage (also current and flux). As I recall, changing >the speed on a requires a change in the field - which one can't do with a PM >field. So the only way to lower the speed and keep the torque up is to use >a PWM power supply. A PM or (shunt wound motor with fixed field) is very sensitive to applied voltage . . . in fact, motor speed is almost directly proportional to applied voltage. If you'd like to dig into the details of motor performance, here is one of dozens of good links on the subjet; http://www.pittmannet.com/pdf/220000ALL.pdf Torque is directly proportional to armature current. Armature current is equal to applied voltage minus counter emf (directly proportional to speed) divided by motor resistance . . . usually a very low number. A pm motor has an counter emf constant, let's say our sample motor is 4 volts per thousand RPM. Let's assume further that the motor has an resistance of .5 ohms. Sooooo . . . if we lock the shaft (zero rpm) and put 14 volts to the motor, we can expect a stall current of 14/0.5 or 28 amps. This would also be very close to the inrush current for getting this motor started. Okay, turn the shaft loose and let's suppose we measure a no-load current of 1.0 amp. We know that 1 amp drops 0.5 volt across the internal resistance so counter-emf must be 13.5 volts. The no load speed is, therefore, 13.5/4 = 3.375 KRPM. Now, let's have our motor drive the flaps down and we measure a max current of say 6 amps. Okay, 6A times 0.5 ohms says counter emf is now 14 - 3 or 11 volts. 11/4 = 2.75 KRPM. Now, let's drop the bus to 10 volts. The flaps are going to take the same TORQUE to lower irrespective of how fast you drive them. So, to maintain the same current (and 3.0 volts of I*R drop) the counter emf MUST drop to 10 - 3 or 7.0 volts. The new flap motor speed is 7/4 = 1.75 KRPM. The motor is doing the same work but at 1.75/2.75 = 63% of the full bus voltage speed. Want a motor that has better speed regulation? Try the same calculations using 0.2 ohms resistance with the same counter emf factor. Bottom line is that a motor's speed can be controlled by ANY means that adjusts it's perceived applied voltage. Duty cycle (or pulse width modulation) switching is no different than turning down the knob on a power supply. Bob . . . ________________________________________________________________________________
Date: Mar 04, 2002
From: Richard Dudley <rhdudley(at)att.net>
Subject: Instrument Lighting
Bob, Is there a preferred architecture for instrument lighting? In a given panel, there may be a combination of many small incandescent lamps in instruments while for those without internal lamps, there are several alternatives such as post lights or even inserts between the instrument and the panel. In addition, modern avionics such as UPS and Garmin have dimmer imput that apparently monitors the dimmer buss and responds as the voltage of the buss is changed. These units are programmable for the "offset" and "slope" of the response. There may be as many as twenty or more lamps and/or dimmer accesses that could be in parallel. Among the questions I have are: 1. Should these all be in parallel with the wiring protected by a single fuse, loosing all if a short occurs in one and the problem of troubleshooting to isolate the offending circuit. Or should they each be fused , a cumbersome prospect: or possibly use in-line fuses on each? Or, should some sort of priority "zoning" be used with each zone having its own fuse? 2. The other aspect of all these lights is the physical connection of all the wires or zoned paralleling of wires. I can imagine using many butt splices and bundling leads from nearby instruments and tying together the butt splices and eventually arriving at the buss. I would appreciate your objective views on how to approach this. Thanks in advance, Richard Dudley -6A finishing N331RD (reserved) ________________________________________________________________________________
Date: Mar 04, 2002
From: Jim and Lucy <jpollard(at)mnsi.net>
Subject: another spark ign. question
Thanks for all the emails about my spark gap question!! Really great stuff. I understand it much better now. Here is another question that probably has a more obvious answer I have wondered about for a while. You get a spark when the points open and the magnetic field collapses due to the magnetic lines of force moving through the secondary coil. So why don't you also get a spark when the points first close and the magnetic field is forming. It seems like it should be moving through the secondary at this time also only the other way ..expanding? Thanks ________________________________________________________________________________
From: jerry(at)tr2.com
Subject: Re: another spark ign. question
Date: Mar 04, 2002
Jim and Lucy wrote: > > > Thanks for all the emails about my spark gap question!! > Really great stuff. I understand it much better now. > > Here is another question that probably has a more > obvious answer I have wondered about for a while. > > You get a spark when the points open and the magnetic > field collapses due to the magnetic lines of force moving > through the secondary coil. > So why don't you also get a spark when the points first > close and the magnetic field is forming. It seems like > it should be moving through the secondary at this time > also only the other way ..expanding? > **** Well, you do. But it's not as strong. The voltage induced in a coil is proportional to the rate of change of the magnetic flux. And the flux collapses faster than it builds. Not only that, but the voltage pulse on point *making* is the opposite polarity from the pulse when the *break*. And the sparkplug is constructed to prefer the breaking polarity. Huh? What difference does it make to the plug what polarity the voltage is? Well, it turns out that it's easier to pull electrons off something sharp and pointy than off something broad and rounded. In fact, it's possible to use a spark gap as a RECTIFIER for high voltage AC. Back in my misspent youth, I had access to a neat book called "The Boy Electrician" or somesuch. One project in "The Boy Electrician" was to build a Geiger counter. ( I think the book dated from the 50's, and there was some interest in atomic energy at that time ). The Geiger tube required a source of high voltage DC, which was ( as I remember ) supplied by a Model T spark coil feeding an adjustable spark gap with one pointy electrode, and one round electrode. The gap would spark only when the pointy electrode was negative. ( The same book showed how to make an Xray tube, which I assume could supply atomic radiation to be counted by the Geiger counter. Scary stuff, from a modern prospective ). - Jerry Kaidor ( jerry(at)tr2.com ) ________________________________________________________________________________
From: "gilles.thesee" <Gilles.Thesee@ac-grenoble.fr>
Subject: Re: Guitar switch suitable for electric flaps ?
Date: Mar 05, 2002
Bob, thank you for yor response. Objet : AeroElectric-List: Re: Guitar switch suitable for electric flaps ? > > > I presume you're interested in having the switch > provide input for 5 positions of flaps. In fact, what we'd like is "up", "takeoff", "normal landing" and "short landing". The double slotted fowler flaps are very powerful past the 35/40 down position. Very steep approaches are possible with the "full down" position. > This arrangement gives you basically infinite > number of flap positions although the > handle is fitted with a couple or three > detents. ..................... > The switch you've cited COULD be used as > you suggest but it takes some intervening > electronics to make it work. The Cessna arrangement is nice and simple , but the kit manufacturer supplies the servo device with a linear pot and limit switches as a standard. > ................... The nice thing about a totally > manual system with a spring loaded, center off > switch is that you still have infinite number of > flap positions and a reliable, SIMPLE, low parts > count system. > Agreed. In a next project, I'll consider using this type of setup or maybe the Cessna device. What we like with the fixed position system is the "switch and forget" functionnality. Thanks for your advice, Gilles France ________________________________________________________________________________
Date: Mar 05, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Guitar switch suitable for electric flaps ?
> > The switch you've cited COULD be used as > > you suggest but it takes some intervening > > electronics to make it work. > >The Cessna arrangement is nice and simple , but the kit manufacturer >supplies the servo device with a linear pot and limit switches as a >standard. > > >................... If the feedback potentiometer is built in, then the hardest part of a servoed flap system is done. Did they include any kind of sample electronics? Further, if you go automatic servo positioning, have you considered the hazards for electronics failure where you get un-commanded flap motion? You might want to consider two switches. One to drive flaps up and down with center being spring loaded off. Then a second switch to select the three flap extension positions. The servo amplifier would be active only in the extend operation causing flaps to stop at the desired location while holding the command switch down. Holding the command switch up will simply drive flaps to their full up position. This system would be incapable of simple electronics failure that would produce un-commanded motion. Also, the Cessna style mechanical feedback could still be applicable to your project . . . the potentiometer would still be used to drive a flap position indicator. Bob . . . ________________________________________________________________________________
Date: Mar 05, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: another spark ign. question
> >Thanks for all the emails about my spark gap question!! >Really great stuff. I understand it much better now. > >Here is another question that probably has a more >obvious answer I have wondered about for a while. > >You get a spark when the points open and the magnetic >field collapses due to the magnetic lines of force moving >through the secondary coil. >So why don't you also get a spark when the points first >close and the magnetic field is forming. It seems like >it should be moving through the secondary at this time >also only the other way ..expanding? Reactive components like inductors and capacitors have dynamic time constants described by: T = RC for capacitance and T = L/R for inductance. When the points open in an ignition coil, R is infinite (paralleled by the capacitor across the points) so the coil field collapses at a rate determined by the resonant frequency of the coil/capacitor combination which is F = 1 / (2*pi*squareroot(LC)). When the points close, there is a dead short across the capacitor and the source impdedance of the charging current is low. Here the T=L/R time constant prevails wherein T is very long compared to the points open model. Voltage output from the coil in this phase is quite low . . . probably too weak to establish any kind of arc Bob . . . ________________________________________________________________________________
From: "Piers Herbert" <piers.herbert(at)ntlworld.com>
Subject: Re: Guitar switch suitable for electric flaps ?
Date: Mar 05, 2002
Garry K was kind enough to send me a copy of the flap control schematic by Mike Palmer which appeared in the December 1999 Kitplanes magazine. This scheme uses a linear pot and a LM324 (quad op amp chip). However I decided this was unsuitable for flap control on the grounds of its active failure modes. Any of several wires loose could result in uncommanded travel. This is also a potential problem with a stick grip flap or trim control scheme if the relays are controlled via the ground side. A chaffed wire could cause uncommanded travel. I have a diagram for the three position system used on the Scottish Aviation Bulldog. This uses four microswitches operated progressively by a cam. Two switches are required to define the intermediate position with a small dead band between them. As far as I can see this scheme has no active failure modes. Any wire loose or chaffed would not cause uncommanded travel. The relays are controlled via the positive side. As the scheme stands it has has only the one breaker. Therefore thicker wire would have to be used throughout. I could use thinner wire for the control part if the cirucit if this part of the circuit was supplied via its own fuse. The scheme also specifies two four pole dual throw relays, using two poles in each relay for the motor reversing circuit and also feding each relay coil via a NC pole on the other relay. I do not understand why it was done this way since the motor reversing circuit can be done with one pole (dual throw) per relay so you would need two poles per relay at most. For three positions I could use a 2-10 toggle switch. I suppose you could extend this scheme to four positions with the guitar switch but that would require six microswitches. Piers. ________________________________________________________________________________
From: BAKEROCB(at)aol.com
Date: Mar 05, 2002
Subject: LR3B-14 Voltage Reg Function
In a message dated 02/22/2002 2:52:43 AM Eastern Standard Time, "Robert L. Nuckolls, III" writes: >.....skip..... one of the requirements I had for configuring the output >stage was that the warning lamp should illuminate IF power were entirely >removed from the regulator.....skip...... In a message dated 02/28/2002 "Robert L. Nuckolls, III" writes: > No, it should be on steady . . . and probably dimmer than > normal brightness but it doesn't flash. 3/5/2002 Hello Bob, Can I please have another bite at this apple? I agree with the above with some clarification / amplification and then a comment and two questions: Clarification: 1) With bus voltage above the level at which the LVWL would be activated: 2) If electrical power is removed from pin 3 of the regulator, but continues to be provided to pin 6 via the alternator switch and alternator circuit breaker the LVWL will flash at its normal brightness. 3) If electrical power is removed from both pin 3 and pin 6 the LVWL will burn steadily at a dim level. (As you say above). 3) above by the opening of the CB feeding pin 3 and that same CB is being used to provide power to the LVWL then the light will not illuminate in any fashion and no warning will be given. Question: Does it not make sense then that if one wants to take advantage of the warning capabilities of the regulator in instances 2) and 3) above that one should power the LVWL from a CB other than the CB feeding bus voltage sense to pin 3? Yet your diagrams and the instructions from B&C provided with the LR3B-14 say to use the same CB for both the LVWL and feeding pin 3. Question: Can you explain? Many thanks. 'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - ?/?/? ________________________________________________________________________________
Date: Mar 05, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Instrument Lighting
> >Bob, > >Is there a preferred architecture for instrument lighting? > >In a given panel, there may be a combination of many small incandescent >lamps in instruments while for those without internal lamps, there are >several alternatives such as post lights or even inserts between the >instrument and the panel. In addition, modern avionics such as UPS and >Garmin have dimmer imput that apparently monitors the dimmer buss and >responds as the voltage of the buss is changed. These units are >programmable for the "offset" and "slope" of the response. My least favorite task on the GP-180 program at Learjet was to architecture the panel dimming control system. The airplane had a broad mix of incandescent, plasma, led, fluorescent, and EL lighting on the panel. Pilots who fly $multimillion$ airplanes like all the illumination to move up and down together on whatever control is used to set intensity. The end result for that airplane was a couple of dimming controllers with individual, programmable outputs that could be tailored to the lighting technology they powered. These things cost over $1500 each in 1983. I advise builders to make space for at least 4 dimmer potentiometers in their panel. At the outset, install only one and hook all the dimming loads to a single dimmer. It will be months after the airplane flies that you will begin to have a sense of what lighted items need different or special attention. If you need to add more controls, you'll be able to do it in a manner that makes them look like they belong there. If you carve your dimmer panel into stone and need to add controls later . . . well . . . The alternative is to spend a LOT of time with a blackout blanket over the canopy working on the dimming system in the shop . . . If it were my airplane, I'd concentrate on getting it flying. Save the enhancements for winter time projects when you can't fly much anyhow. >There may be as many as twenty or more lamps and/or dimmer accesses that >could be in parallel. > >Among the questions I have are: > >1. Should these all be in parallel with the wiring protected by a single >fuse, loosing all if a short occurs in one and the problem of >troubleshooting to isolate the offending circuit. Or should they each be >fused , a cumbersome prospect: or possibly use in-line fuses on each? >Or, should some sort of priority "zoning" be used with each zone having >its own fuse? This isn't done . . . common shorts during production caused a LOT of damage to dimmers at Beechcraft on the Bonanza and Baron lines about 25 years ago. I designed a short-proof dimmer that would simply shut down when overloaded. Once all the shorts are fixed, the dimmer would operate normally. Our dimmers are similarly short proof. >2. The other aspect of all these lights is the physical connection of >all the wires or zoned paralleling of wires. I can imagine using many >butt splices and bundling leads from nearby instruments and tying >together the butt splices and eventually arriving at the buss. You can use a D-sub connector to build a minibus immediately adjacent to the instruments being lighted. Fixture wires can be brought to this common point close by the instruments so that an array of many lights can be neatly wired and powered through a single dimmed power and ground wire running from the panel to the dimmer. See: http://209.134.106.21/articles/minibus/minibus.html Bob . . . ________________________________________________________________________________
From: jerry(at)tr2.com
Subject: Re: Instrument Lighting
Date: Mar 05, 2002
Robert L. Nuckolls, III wrote: > > > >In a given panel, there may be a combination of many small incandescent > >lamps in instruments while for those without internal lamps, there are > >several alternatives such as post lights or even inserts between the > >instrument and the panel. In addition, modern avionics such as UPS and > >Garmin have dimmer imput that apparently monitors the dimmer buss and > >responds as the voltage of the buss is changed. These units are > >programmable for the "offset" and "slope" of the response. > *** The GNS430 is programmable for either following a lighting buss, or working off a photocell in its faceplate. In my Sundowner, I was unable to make it do anything sensible in terms of following the dimmer bus. Here's the deal: during the day, you want the radio at full brightness, otherwise you can't see it. You don't care about the rest of the lamps. During the night, you want the radio's brightness set way down, outherwise it overpowers the rest of the panel - not to mention your own night vision. But you want the rest of the lights set to some reasonable brightness. The radio almost wants to be "brightness inverted" with respect to all the instruments, post lights, etc. I punted and set it to work off its photocell. But I think it really deserves its own brightness pot. Phew, I'd have to do a 337, get a field approval, and modify the FMS for the radio.... Hmm, what if I mounted a post light next to the photocell? :) - Jerry Kaidor ( jerry(at)tr2.com ) ________________________________________________________________________________
Date: Mar 05, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: LR3B-14 Voltage Reg Function
> > In a message dated 02/22/2002 2:52:43 AM Eastern Standard Time, "Robert L. > Nuckolls, III" writes: > > >.....skip..... one of the requirements I had for configuring the output > >stage was that the warning lamp should illuminate IF power were entirely > >removed from the regulator.....skip...... > > In a message dated 02/28/2002 "Robert L. > Nuckolls, III" writes: > > > No, it should be on steady . . . and probably dimmer than > > normal brightness but it doesn't flash. > >3/5/2002 > >Hello Bob, Can I please have another bite at this apple? I agree with the >above with some clarification / amplification and then a comment and two >questions: > >Clarification: > >1) With bus voltage above the level at which the LVWL would be activated: > >2) If electrical power is removed from pin 3 of the regulator, but continues >to be provided to pin 6 via the alternator switch and alternator circuit >breaker the LVWL will flash at its normal brightness. > >3) If electrical power is removed from both pin 3 and pin 6 the LVWL will >burn steadily at a dim level. (As you say above). > >3) above by the opening of the CB feeding pin 3 and that same CB is being >used to provide power to the LVWL then the light will not illuminate in any >fashion and no warning will be given. > >Question: Does it not make sense then that if one wants to take advantage of >the warning capabilities of the regulator in instances 2) and 3) above that >one should power the LVWL from a CB other than the CB feeding bus voltage >sense to pin 3? > >Yet your diagrams and the instructions from B&C provided with the LR3B-14 say >to use the same CB for both the LVWL and feeding pin 3. > >Question: Can you explain? Power to pin 3 is just a sense lead and has very little current flowing in it . . . a few tens of milliamps as I recall. Likelihood of this breaker/fuse opening is very remote. Mechanical failure of some kind is the most probable cause. If this concerns you, you can move + source for the lamp to any other handy point. Bob . . . ________________________________________________________________________________
Date: Mar 06, 2002
Subject: dimmer question
From: czechsix(at)juno.com
Bob, Just a question about how your dimmers work in terms of dissipating power. What exactly does the heat sink do? Is it dissipating extra energy when the dimmer is turned down, or up?? (excuse my excessive ignorance...) One of the things I'm wondering on the subject of panel dimming is do I need a panel lights On/Off switch (more clutter and an extra failure point) or can I just wire up the dimmer to the lights and during the day turn the dimmer all the way down to minimize power draw from it? Thanks, --Mark Navratil Cedar Rapids, Iowa RV-8A finish kit stuff... ________________________________________________________________________________
From: "gilles.thesee" <Gilles.Thesee@ac-grenoble.fr>
Subject: Re: Guitar switch suitable for electric flaps ?
Date: Mar 06, 2002
----- Message d'origine ----- De : "Robert L. Nuckolls, III" : Envoy : mardi 5 mars 2002 14:32 Objet : AeroElectric-List: Re: Guitar switch suitable for electric flaps ? > If the feedback potentiometer is built in, then > the hardest part of a servoed flap system > is done. Did they include any kind > of sample electronics? > > Further, if you go automatic servo positioning, > have you considered the hazards for electronics > failure where you get un-commanded flap motion? > > You might want to consider two switches. One > to drive flaps up and down with center being > spring loaded off. Then a second switch to > select the three flap extension positions. The > servo amplifier would be active only in the > extend operation causing flaps to stop at the > desired location while holding the command > switch down. Holding the command switch up > will simply drive flaps to their full up position. > This system would be incapable of simple electronics > failure that would produce un-commanded motion. > > Also, the Cessna style mechanical feedback could > still be applicable to your project . . . the > potentiometer would still be used to drive > a flap position indicator. Bob and Piers, Thank you for your messages. Now I realize I have to dig deeper into that servo system before making decisions. We'll call the kit manufacturer to get thir schematics. thanks again, Gilles ________________________________________________________________________________
Date: Mar 06, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: dimmer question
> >Bob, > >Just a question about how your dimmers work in terms of dissipating >power. What exactly does the heat sink do? Is it dissipating extra >energy when the dimmer is turned down, or up?? (excuse my excessive >ignorance...) One of the things I'm wondering on the subject of panel >dimming is do I need a panel lights On/Off switch (more clutter and an >extra failure point) or can I just wire up the dimmer to the lights and >during the day turn the dimmer all the way down to minimize power draw >from it? In the early days of panel illumination, power to the lamps was controlled by simple rheostat . . . a panel mounted, knob adjustable power resistor. Full clockwise rotation reduced the resistance to zero and the lamps were fully illuminated. Rotation CCW increased resistance and intensity goes down. Simple and at that time, not terribly expensive because rheostats were common catalog items in many sizes. The problem with rheostats are several fold. First, they DO get hot . . . energy that is not fed to lamps is used up in the rheostat and shed in the form of heat. The rheostat's total resistance needed to be adjusted to accommodate the number of lamps in the circuit. Often, there was no ideal catalog item so compromises were made in performance. In some cases, aircraft companies designed and ordered special rheostats with features not available off-the-shelf. The price went up. The dimmers we sell are "smart rheostats" . . . they still dump off unneeded eneregy in the form of heat. However, instead of being constant resistance devices they are constant voltage devices with the smarts to hold output constant based on control knob position and irrespective of bus voltage fluctuations. Anohter advantage of the current design is that heat is dumped off remote from the panel control. Further, the panel control can now be a miniature potentiometer . . . much more panel friendly. I recall riding in a Cessna 310 one night where the panel around two dimmer rheostats (each about 3" in diameter and 1.5" deep behind panel) ran so hot that you could not hold your finger on the panel material around the knob. The two rheostats used up about 20 square inches of panel space . . . now we can put each control pot in less than 1 square inch of space and heat comes off the panel. When the lamps are turned all the way up, very little power is dissipated in the dimmer assembly (max amps times about 1 volt drop = low watts). When the lamps are turned all the way down we have a little more energy dumped (minimum amps times 10 volts of drop = a bit more power). Maximum heat is generated when the lamps are at some medium intensity where there is significant current at about 7-8 volts of drop = most watts). The dimmers we sell are designed to stop dimming when the lamps are just above dull red glow . . . and emitting least usable amount of light. This happens at about 4 volts. If we took the control all the way down to minimum for the dimmer regulator, there would a significant amount of control rotation that produced no visible changes in light output . . . poor design. The power consumed by the dimmer system at minimum intensity is very small compared to the output of your alternator. Life of bulbs at 4 volts is measured in centuries . . . so adding a switch to control them is of no practical benefit. Having said all that, it's important to note that even at minimum intensity operation, your full up a Christmas display of panel lighting can be large compared to the energy it takes to run really useful things like radios. This is why we recommend the e-bus be loaded with single lamp illumination sources like our map light or a single flood lamp in the overhead. It's possible to SEE quite well with very little energy devoted to panel illumination. Bob . . . ________________________________________________________________________________
Date: Mar 06, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Guitar switch suitable for electric
flaps ? > > >Bob and Piers, > >Thank you for your messages. >Now I realize I have to dig deeper into that servo system before making >decisions. >We'll call the kit manufacturer to get thir schematics. > >thanks again, > >Gilles Could you ask them to fax a copy to me too? 316.685.8617 If we're all looking at the same piece of paper, we're in a better position to evaluate the design. Bob . . . ________________________________________________________________________________
Date: Mar 06, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: AFP Fuel Injection Boost Pump
> > >A couple of questions Bob, > >I was talking to AFP today and they recommend a 10 amp fuse and 20 AWG >for their FI boost pump because it has a 7 amp surge at start and a 5 >amp continuous power requirement. Your Z11 has 3 amp and 22 AWG. Sould >I upgrade this to 7 and 20? 10A fuse is inappropriate for 20AWG wire . . your suggestion for 7A fuse and 20AWG is well considered. >Also, I want to put either a 3 amp CB switch or a toggle switch >someplace hidden to prevent engine start, say on the line between the >Battery Contactor solenoid terminal and the Battery/Alternator Master >Switch. What do you think of location and switch preference? This has been well thrashed on the list with perhaps a half dozen "solutions" offered and considered. My personal opinion is that most of our fears in this regard are ill-founded. In most cases where security is required (like an air show flight line) you may well be required to unhook a battery terminal. Anything you want to do to is probably as useful as anything suggested here on the list. Bob . . . ________________________________________________________________________________
From: "gilles.thesee" <Gilles.Thesee@ac-grenoble.fr>
Subject: Re: Guitar switch suitable for electric flaps
?
Date: Mar 06, 2002
> > > > > > > >Bob and Piers, > > > >Thank you for your messages. > >Now I realize I have to dig deeper into that servo system before making > >decisions. > >We'll call the kit manufacturer to get thir schematics. > > > >thanks again, > > > >Gilles > > Could you ask them to fax a copy to me too? 316.685.8617 > > If we're all looking at the same piece of paper, we're in > a better position to evaluate the design. > > Bob . . . Bob, Will do. Thanks Gilles ________________________________________________________________________________
Date: Mar 06, 2002
Subject: Vans tach sender
From: czechsix(at)juno.com
Anybody know how Vans tach sender works (the one that plugs into the tach drive on the accessory case and is then wired up to their tach gauge)? I'm wondering if it is a frequency generator of some sort that might be compatible with the Grand Rapids EIS 4000 engine monitor (which is designed to pick up pulses from a mag P lead). I asked Vans about it and haven't received any response. I'd rather use a pickup off the tach drive so that I don't have to depend on one ignition source or the other to get rpm (or use a switch between the two mags when doing a mag check). Thanks, --Mark Navratil Cedar Rapids, Iowa RV-8A finish kit stuff... ________________________________________________________________________________
Date: Mar 06, 2002
Subject: 115V 400Hz power
From: Grant Corriveau <grantC(at)total.net>
on 3/5/02 02:51, AeroElectric-List Digest Server at aeroelectric-list-digest(at)matronics.com wrote: > From: "Russ Werner" <russ(at)maui.net> > Subject: Re: AeroElectric-List: Re: Laptop power in the cockpit > > > Bob and Dan, > > I have personal experience using the 115 V 400 Hz power in Boeing and > Douglas airplanes. I have never seen a problem. These outlets aren't > normally supplied to passengers, but the crew routinely use them to run > and/or charge their various electronics including laptops. I have used it > myself on 3 or 4 different computers with no ill effect. > > Russ Werner > Maui When Airbus discovered that flight crews and others (i.e. pax in the washrooms) were using these plugs for laptop computers, they issued a 'Do not do this' bulletin, citing dangers of overheating, fire and explosion of the battery chargers/converters due to the difference in Hz. I'm not an expert in this stuff at all, so I just pass it on as food for thought. Grant ________________________________________________________________________________
From: jerry(at)tr2.com
Subject: Re: 115V 400Hz power
Date: Mar 06, 2002
Grant Corriveau wrote: > > > Douglas airplanes. I have never seen a problem. These outlets aren't > > normally supplied to passengers, but the crew routinely use them to run > > and/or charge their various electronics including laptops. I have used it > > myself on 3 or 4 different computers with no ill effect. > > *** You're probably getting away with it because of the current design of computer power adaptors: they don't have 60Hz power transformers anymore. Instead, they rectify the AC and use it to drive a high-frequency oscillator. The output of the oscillator is goes through a toroidal transformer ( which can be small & light because of the high frequency ). The intent is to make the supplies small and light. The side effect is to make the 400 Hz not matter. - Jerry Kaidor ( jerry(at)tr2.com ) ________________________________________________________________________________
From: "Tom Barnes" <skytop(at)megsinet.net>
Subject: Avionics cooling requirements
Date: Mar 06, 2002
Bob, I have a Garmin GNS430 and GTX327 which each has a nipple for air, which leads me to think maybe it is required. (Above the 430 is a small audio panel). For the sake of argument, let's say I want to ALWAYS have a fan ON when the avionics are ON. Two questions: 1) how much volume is needed and can volume be translated to electrical power? 2) Does it matter if the volume is forced in, or pulled out (suction)? If suction would work, I would want to use the exhaust in place of a windshield defroster blower; see any problems with this? I live in the North, but have to plan for some trips to Texas and Florida. I will appreciate your comments. Thanks, Tom Barnes -6 electrical ________________________________________________________________________________
From: "John Harlow" <jharlow(at)onearrow.net>
Subject: Re: Avionics cooling requirements
Date: Mar 06, 2002
I have the GNS 430 and a King KT-76C transponder that require air cooling. I have installed the Ameri-KingAK-920 cooling fan. It comes on with the avionics switch and has worked great for the last 2 yrs. I live in Florida and would not be without some source of cooling. John ________________________________________________________________________________
From: George Braly <gwbraly(at)gami.com>
Subject: RE: Ignition -
Date: Mar 06, 2002
Robert, did you get the fax on the spark "enhancer" ? -----Original Message----- From: Robert L. Nuckolls, III [mailto:nuckolls(at)kscable.com] Subject: AeroElectric-List: RE: Ignition - > >Tyndar press. Whatever that is. > >Lib of Congress number 97-90492. > >I don't think it really has much to do with the shower of sparks. > >And it doesn't appear to have much use except as a novelty and in the noted >area of the jet engine igniter. > >Also, I suspect a dual gap system would be a real joy in the RF noise >area!!! Searched for the publisher and didn't turn up anything. Could you photocopy a few pages of description and any figures that come with it? I'd like to see it. > * * * * * * * > > >I've been busy... see www.engineteststand.com Damn George, you got more expensive toys than I do! As you well know, it takes good and sometimes expensive toys to do the best work. How far is your facility from the Ada airport? >Very much like your mail list page. You do good work! Thank you sir! Bob . . . http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
Date: Mar 07, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: I need help in selecting electrical
system > > >I'm not going to have a vacuum pump. That means I could install an SD-8 >Alternator right? Since you've raised the issue, assuming that's what you >meant, I can't get real excited about it. Let me tell you why and you make >my day and tell me where I'm wrong. It's another piece of hardware to >maintain/malfunction, it has weight, and isn't cheap ($430 + $65 for ov >protection). Yeah but it weighs only 3.5#, has a very long life. If you have an electrically dependent engine, I'd rather have two alternators than two batteries . . especially if they are B&C alternators. A second 17 a.h. battery weighs 15+ pounds and needs periodic replacement. The second alternation weighs 1/5 that of the battery and will run gizmos to the tune of it's full output as long as the engine is turning. >You wrote on the list on 2/24 that the SD-8 "comes with a regulator that >needs a >battery but it may be possible to build one that isn't". Also, "hard to >controll output efficiently and power generation not efficient". I don't >get a warm a feeling from that. Seems to me, if I wanted more >reliability, it would be easier, cheaper, possibe? to install a second >battery. Cheaper initially . . . but I think the cost of ownership over 5-10 years is lower and the airplane is 12# lighter. Bob . . . ________________________________________________________________________________
Subject: Ford Regulator
From: "Bruce Uvanni" <buvanni(at)us.ibm.com>
Date: Mar 07, 2002
03/07/2002 08:35:48 AM Bob: I have a V166 Ford regulator. I also have a 60 amp alternator from Mark L. There are three wires coming out of the reg. 1) field 2) ground 3) staitor Do I use the staitor wire? I have the connectors A & S on the reg. tied together with the positive side of the crowbar to my master/battery switch. I know the f term on the reg is for the field. The ground will go to the engine ground. Also I'm planning on using #4 welding cable for my battery connections ( from B&C). Is this alright or should I be using #2 Thanks BRUCE UVANNI RV6A FWF / Panel BUVANNI(at)US.IBM.COM PHONE: (802) 769-2822 ________________________________________________________________________________
Date: Mar 07, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Ford Regulator
> > >Bob: I have a V166 Ford regulator. I also have a 60 amp alternator >from Mark L. There are three wires coming out of the reg. >1) field >2) ground >3) staitor > >Do I use the staitor wire? I have the connectors A & S on the reg. >tied together with the positive side of the crowbar to my >master/battery switch. I know the f term on the reg is for the field. >The ground will go to the engine ground. The "S" terminal is one of the power input pins to the regulator and needs to be jumpered to the "A" terminal. Ground is make to the regulator's case. Mount the regulator on the firewall and this connnection is covered. "F" does indeed go to the alternator's field terminal. See Figure Z-23 of http://209.134.106.21/articles/Rev9/ch10-9.pdf >Also I'm planning on using #4 welding cable for my battery >connections ( from B&C). Is this alright or should I be using #2 If your battery is in front of the airplane, #4 will suffice for all fat wires. If your battery is behind the seat, use 2AWG to bring the heavy current forward . . . #4 soft jumpers are still fine for the battery connnections. Bob . . . ________________________________________________________________________________
Date: Mar 07, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: RE: Ignition -
> > >Robert, did you get the fax on the spark "enhancer" ? Yes. Thank you. I've .pdf'd the pertinent pages and I'm going to publish them for enlightenment of the group. I STILL don't understand the physics of what's happening. Bob . . . ________________________________________________________________________________
Date: Mar 07, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Ford Regulator -OOPS! WRONG LINK
> > > > > > > >Bob: I have a V166 Ford regulator. I also have a 60 amp alternator > >from Mark L. There are three wires coming out of the reg. > >1) field > >2) ground > >3) staitor > > > >Do I use the staitor wire? I have the connectors A & S on the reg. > >tied together with the positive side of the crowbar to my > >master/battery switch. I know the f term on the reg is for the field. > >The ground will go to the engine ground. > > The "S" terminal is one of the power input pins to the > regulator and needs to be jumpered to the "A" terminal. > Ground is make to the regulator's case. Mount the regulator on > the firewall and this connnection is covered. "F" does > indeed go to the alternator's field terminal. See > Figure Z-23 of > > http://209.134.106.21/articles/Rev9/ch10-9.pdf Sorry 'bout that. Clicked on the wrong link to paste to my last reply. The REAL link is: http://209.134.106.21/articles/Rev10/z10.pdf Bob . . . ________________________________________________________________________________
Date: Mar 07, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Vans tach sender
> >Anybody know how Vans tach sender works (the one that plugs into the tach >drive on the accessory case and is then wired up to their tach >gauge)? I'm wondering if it is a frequency generator of some sort that >might be compatible with the Grand Rapids EIS 4000 engine monitor (which >is designed to pick up pulses from a mag P lead). I asked Vans about it >and haven't received any response. I'd rather use a pickup off the tach >drive so that I don't have to depend on one ignition source or the other >to get rpm (or use a switch between the two mags when doing a mag check). It's probably specific to the instrument that uses it's signal. I've designed several variations on this same theme that are in no way interchangeable with each other. It MIGHT work but you'd have to have some detailed design from both companies to see if you can do some practical interface . . . but odds are against you. Why not "depend" on a single source? In the relatively rare case that the single mag driving the monitor fails or needs to be shut off . . . how does this affect your probability of comfortable termination of that flight? Tachometers are among the least useful instruments on the panel and wings don't fall off if the tach craps. Bob . . . ________________________________________________________________________________
From: DanJE(at)aol.com
Date: Mar 07, 2002
Subject: Airline power sources
LONG message about Airline Power Sources! OK... I thought we were finished with the topic of airline cockpit power sources, computers, GPS, and other things that pilots like to plug in... . but apparently not! (Fine with me, because I never got a satisfactory answer to my original questions anyway!) Russ Werner of Maui writes: <<< I have personal experience using the 115 V 400 Hz power in Boeing and Douglas airplanes. I have never seen a problem. These outlets aren't normally supplied to passengers, but the crew routinely use them to run and/or charge their various electronics including laptops. I have used it myself on 3 or 4 different computers with no ill effect.>>> My comment: Glad to hear it, Russ. But... I distinctly remember from my USAF days during the Viet Nam war that we were all warned not to plug normal 115v devices into aircraft 400hz outlets, even though they 'looked' like a house outlet, because 400 hz would 'fry' most anything not built for it. In particular, they showed us photos of those rechargeable flashlights all pilots were buying at the time, (white, rectangular case, about 5 inches long, had both a red and a white bulb in the end, little reversible 115v plug used for recharging the ni-cad battery inside). Pilots, especially on C-130s, would try to recharge them using 400 hz outlets -- with disastrous results. The photos showed how this action resulted in melted flashlights at best, and I think an inflight fire at worst. Therefore, I'm quite leary of using most 115v 60hz devices in a cockpit, but do understand that most of the modern day computer power adapters have been built with the flexibility to handle almost anything. I know the modern Sony and HP laptops come with a power adapter that is labled to handle 100v-250v, 50/60 hz input. That's a wide variety, and to think no matter what, it puts out 19 volts for your laptop! But.... it didn't say 50-400hz. I wish it would. I'd feel more comfortable. Jerry Kaidor writes: <<< You're probably getting away with it because of the current design of computer power adaptors: they don't have 60Hz power transformers anymore. Instead, they rectify the AC and use it to drive a high-frequency oscillator. The output of the oscillator is goes through a toroidal transformer ( which can be small & light because of the high frequency ). The intent is to make the supplies small and light. The side effect is to make the 400 Hz not matter.>>> OK... So this is lighter (and more adaptable) than a heavy wire-wound transformer /rectifier in the first place! At least I feel more comfortable using one of these modern laptop power supplies on 400 hz input! But I'd like to use someone else's, not my own! Grant Corriveau wrote: <<>> Well, I'm certainly not an expert on this either, just looking for good advice, but I am an airline Captain for a 'major airline' (can't really say the name, but it begins with a big letter "U" and has been associated with phrases like "friendly skies" and "Rising" which meant absolutely nothing to anyone, so they dropped it and we currently have no catchy phrase, motto, or brand association). As for outlets, my airline no longer has any working 115v 60hz outlets in the lavatories that I'm aware of. Those that remain have been deactivated, whether they are labled that way or not. Even the new Boeing 777 HAS a nice power supply that creates 115v 60 Hz located behind every lavatory mirror (yeah, you can take a peek -- theres a secret button you push up, loacted just under the mirror / paper towel dispenser), but my airline chose not to have the outlets installed in the mirror base. The power goes to a dead end. But.. you WILL find a 115v 400 hz outlet in darn near EVERY airliner somewhere near door 1L (one, Left). Look around. Its usually near the floor sometimes on the door frame, sometimes below the flight attendant jumpseat, sometimes in the galley. The purpose of this is to provide power for certain tools used during interior installation, or for certain Boeing test equipment, (the outlet in the cockpit is primarily for this purpose); or more common... the purpose in the cabin is to provide power for specially built vacuum cleaners designed to operate on 115v 400hz. You don't see these very often these days... The last one's I saw were in Hong Kong. Airline carpets in the USA are filthy these days... I have seen passengers try to plug their computers into these cabin utility 400hz outlets. Usually, the flight attendants discourage them, but on long flights (say 14 hours to Sydney or Hong Kong), some passengers talk their way into using them. I've also seen passengers leave computers plugged into the 'shaver outlets' in the lavatories, back when they used to work. I'm not sure those outlets had the current flow ability to charge a computer, however. What uses more... a shaver or a computer power supply? Most of those outlets don't really look like a house outlet-- the aircraft version is a rounded outlet, and I think the intent is you plug in and rotate the plug a tiny bit to the right to lock it in. But a straight prong, non-polarized, 115v 60 hz plug will fit if you try. Therefore, you could plug a computer into one. Computer power at airline seats: Both Delta and United (perhaps others) came up with a great idea to provide passengers (at least first class, maybe business class as well) with a 15 volt outlet at their seats a couple years ago. They failed to decided upon a common outlet, so passengers had to buy two different models or an interchangeable plug for their cords. Radio Shack sold them. The airlines also failed to take advantage of the market -- they could (and should) have sold them at the gate prior to boarding! Sadly, United (not sure about Delta), has begun DE-activating all these 15 volt outlets, at least on the 777, and probably the 767 and 747-400 aircraft as well, citing some sparks or a fire somewhere on a plane as the reason. The power supply is still in the closet somewhere, and there is a master power switch there, too, but most don't work anymore. Too bad.. This was a terrific sales idea that the passengers really liked. They complain bitterly each day as they discover the plane has outlets -- but they don't work. I'm also wondering why the airlines chose 15 volts when all the Sony, HP, and Compaq computers I've seen like to see 19 volts? Sure, they operate on 11.6 volt internal batteries, but as Bob Knuckolls pointed out, they don't get a charge if you try to operate on 12 volts input. Perhaps 15 volts is enough, but why not 19 volts in the first place? 28VDC outlets: The Boeing cockpits all have a 28VDC outlet, with a round outlet. The plug that goes into it has to have one straight prong, and one curved one, shaped like a parenthesis ) . I.e., it looks like this: | ) . (Sorry this is getting SO LONG.. but there is lots to cover here!) Bob answered my question with a couple of URLs that took me to some nice photos of devices that looked like some ICs on a heat sink, but no information on how or where to buy one, nor the circuit to build one. http://209.134.106.21/temp/apc15-14a.jpg That's one of them. An 'adjustable power conditioner'. That's pretty big for what I need! And I would need the circuit for that thing anyway. If I could find the correct plug, I could wire it to a small device that takes in 28vdc and outputs 19vdc for a computer! WHERE could I find a device that does just that? Converts 28vdc to 19vdc, no matter what the load on the user end? And, could I get one that doesn't care too much what the input voltage is? I'd like to get one that takes in 12vdc-28vdc and puts out a constant 19vdc! What does that look like? Is it nice a small and lightweight so I can carry it on every trip? I could also use it on my computer in my car! Sorry this got so long... but I STILL need the answer: I'm reluctant to plug anything that's labeled 50/60hz input into a 400hz outlet, so I want to go with the 28VDC source. How can I do that, what do I need, and where can I get it? Dan Eikleberry Las Vegas ________________________________________________________________________________
From: jerry(at)tr2.com
Subject: Re: Airline power sources
Date: Mar 07, 2002
DanJE(at)aol.com wrote: > > > LONG (interesting) message about Airline Power Sources! [----------snip----------] > > > WHERE could I find a device that does just that? Converts 28vdc to 19vdc, > no matter what the load on the user end? *** Not too hard. A simple circuit with a "three terminal regulator" will do it. But making it small and light will be hard. Here's why: Suppose your laptop wants an amp at 19V - this seems typical. The three terminal regulator will accurately drop the 28V to 19V by inserting a sort of dynamicly adjusting resistor (actually transistor ) in line with the current. This resistor will generate heat. How much heat? P ( power ) equals E ( voltage ) times I(current). E here is the voltage DROP across the regulator. 28V - 19V = 9 volts. Current is an amp. Power is 9V times 1 amp, or 9 Watts. So you'll need a heat sink, which porks up the package somewhat, although 9 watts isn't all THAT much. You might be able to minimize the heatsink requirements by putting a series diode string before the input to the 3-terminal regulator. Each diode drops .7 volts. You should really have 5 volts of head room for the regulator, which means you want a minimum of 24 volts at its input. If you know what the minimum voltage output of the socket is, you subtract 24 volts from that, divide by .7V per diode, and then you come up with how many diodes to put in the string. If you tweek the design for 5V headroom, then your regulator only has to dissipate 5 watts instead of 9. And, could I get one that doesn't > care too much what the input voltage is? I'd like to get one that takes in > 12vdc-28vdc and puts out a constant 19vdc! *** This is harder. It can be done. You have to design a switching regulator, which is somewhat outside the "do-it-yourself" level of complexity. If you see a market for this, I have a friend who is expert at designing switching power supplies, and who could use some consulting work.... - Jerry Kaidor ( jerry(at)tr2.com ) ________________________________________________________________________________
From: "Piers Herbert" <piers.herbert(at)ntlworld.com>
Subject: Re: Airline power sources
Date: Mar 07, 2002
> WHERE could I find a device that does just that? Converts 28vdc to 19vdc, > no matter what the load on the user end? And, could I get one that doesn't > care too much what the input voltage is? I'd like to get one that takes in > 12vdc-28vdc and puts out a constant 19vdc! > What does that look like? Is it nice a small and lightweight so I can carry > it on every trip? I could also use it on my computer in my car! Sounds like our old friend LM317 to me. At least that should work off the 28v supply. It won't step up though. To step up dc I suppose you would need an inverter - transformer - rectifier set up? Piers ________________________________________________________________________________
Date: Mar 08, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: S704-1 starter run-onrelay for PM starter
> > >Hi Bob, >In Fig Z-22 there is a fix for "run-on" in PM starters like Sky-Tec. >The description says it buffers the panel mounted start button from very >high inrush currents. Is that another way of saying it protects the >starter button? Sure . . >I presume you still get the in-rush and need to start the prop spinning >and get past the high in-rush period before turning on the EI's to >prevent the possibility of kick-back. No . . . this shouldn't be an issue. The relay's primary task is to protect the starter switch while providing positive disconnect of the built-in starter contactor at starter release so that you don't get delayed dis-engagement due to generator action of the starter motor as it spins down. The inrush currents being considered here are associated only with characteristics of the contactor. See: http://209.134.106.21/articles/strtctr.pdf Bob . . . ________________________________________________________________________________
Date: Mar 08, 2002
From: Gary Liming <gary(at)liming.org>
Subject: mounting inline components
I have a couple of places where I would like to add in-line components - one place is for a diode to drop the voltage slightly, another is to add resistors. I there a good way to add them in-line without the bulk of a barrier strip with screw friction connections? The connections I am talking about is to join stranded wires to solid wire component leads, or just solid leads to solid leads. I was thinking about maybe a knife connector on the leads and stranded wire, along with a high temp plastic strip inside the shrink wrap for some added strength. Any better ideas? Thanks, Gary Liming ________________________________________________________________________________
Date: Mar 08, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: mounting inline components
> > >I have a couple of places where I would like to add in-line components - >one place is for a diode to drop the voltage slightly, another is to add >resistors. I there a good way to add them in-line without the bulk of a >barrier strip with screw friction connections? The connections I am >talking about is to join stranded wires to solid wire component leads, or >just solid leads to solid leads. I was thinking about maybe a knife >connector on the leads and stranded wire, along with a high temp plastic >strip inside the shrink wrap for some added strength. Any better ideas? Where do you need to drop a voltage just 0.6 volts and why? You really have my curiosity stoked here . . . For small components like that, I cut the leads on the component to about .25" long. Strip .25" of 22 or 20AWG leadwire and solder to component with a simple lap joint. Use small heatshrink over each joint and then two layers of heatshrink over the whole assembly including the joints. I you can find some heavy, internal melting wall heatshink for the outer layer, a single overall layer of shrink will suffice. Bob . . . ________________________________________________________________________________
Date: Mar 08, 2002
From: Gary Liming <gary(at)liming.org>
Subject: Re: mounting inline components
> Where do you need to drop a voltage just 0.6 volts and why? > You really have my curiosity stoked here . . . I am putting camera mounts in the wings, and the camera is designed for 12 volts, and the manufacturer suggested putting a couple of diodes in series in front of the camera power to drop the 14v down a bit, which made sense to me. The nominal current draw is 180 ma, so heat is not a problem. Pictures of the mount and the camera fixture are on the instrument and wings pages of www.liming.org/ch801. > For small components like that, I cut the leads on the component > to about .25" long. Strip .25" of 22 or 20AWG leadwire and solder > to component with a simple lap joint. Use small heatshrink over > each joint and then two layers of heatshrink over the whole assembly > including the joints. > > I you can find some heavy, internal melting wall heatshink > for the outer layer, a single overall layer of shrink will > suffice. Ok, will do. And thanks. Gary Liming ________________________________________________________________________________
Date: Mar 09, 2002
From: Graham Singleton <grasingleton(at)avnet.co.uk>
Subject: Re: Vans tach sender
>Anybody know how Vans tach sender works (the one that plugs into the tach >drive on the accessory case and is then wired up to their tach >gauge)? I'm wondering if it is a frequency generator of some sort that >might be compatible with the Grand Rapids EIS 4000 engine monitor (which >is designed to pick up pulses from a mag P lead). I asked Vans about it >and haven't received any response. I'd rather use a pickup off the tach >drive so that I don't have to depend on one ignition source or the other >to get rpm (or use a switch between the two mags when doing a mag check). >--Mark Navratil I can make a guess that it might be what used to be referred to as a tacho generator. Simply a DC generator the voltage of which depends only on rpm. I have an old one in a box somewhere in my shop. There used to be a Carr (?) tacho that worked the same way. It had a nice 270 degree display. Graham ________________________________________________________________________________
Date: Mar 08, 2002
From: Richard Dudley <rhdudley(at)att.net>
Subject: Switch numbering
Bob, I'd just like to confirm switch numbering. Some of your drawings show Microswitch toggle switches while others show your S700-2-XX switches. It appears that the numbering differs between the two sources. I have concluded that the numbering (with the keyway up viewed from the back) is 1-2-3 bottom to top on the left and 4-5-6 bottom to top on the right for the S700-2-XX and for the Microswitch the left and right numbering is interchanged or 1-2-3 bottom to top on the right and 4-5-6 bottom to top on the left. Is this correct? Thanks in advance. Richard Dudley -6A finishing N331RD reserved ________________________________________________________________________________
Date: Mar 08, 2002
From: Richard Dudley <rhdudley(at)att.net>
Subject: Re: Vans tach sender
There has been a continuing thread about both errors in the tachometer and effects of RF on the tachometer and manifold pressure gauge. I have read several posts reporting tachometer errors and indicator changes when transmitters are keyed. My question is: Does anyone with these instruments have good results? Has the tachometer been calibrated and found within reasonable tolerances (+-10%?)? Has anyone's installation been immune to RF. That is unaffected when your transmitter is keyed? Richard Dudley -6A finishing N331RD reserved Graham Singleton wrote: > > > >Anybody know how Vans tach sender works (the one that plugs into the tach > >drive on the accessory case and is then wired up to their tach > >gauge)? I'm wondering if it is a frequency generator of some sort that > >might be compatible with the Grand Rapids EIS 4000 engine monitor (which > >is designed to pick up pulses from a mag P lead). I asked Vans about it > >and haven't received any response. I'd rather use a pickup off the tach > >drive so that I don't have to depend on one ignition source or the other > >to get rpm (or use a switch between the two mags when doing a mag check). > >--Mark Navratil > > I can make a guess that it might be what used to be referred to as a tacho > generator. Simply a DC generator the voltage of which depends only on rpm. > I have an old one in a box somewhere in my shop. There used to be a Carr > (?) tacho that worked the same way. It had a nice 270 degree display. > > Graham > ________________________________________________________________________________
From: "Gary Casey" <glcasey(at)gte.net>
Subject: in-line components
Date: Mar 09, 2002
<> I've done that, but usually I, after soldering as described above, double the leads back over the component on opposite sides. This creates an "S" configuration with the component itself providing the structure and the separation of the exposed leads. Then the whole thing is shrink-wrapped. Gary Casey ________________________________________________________________________________
Date: Mar 09, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: in-line components
> >< to about .25" long. Strip .25" of 22 or 20AWG leadwire and solder > to component with a simple lap joint. Use small heatshrink over > each joint and then two layers of heatshrink over the whole assembly > including the joints.>> > >I've done that, but usually I, after soldering as described above, double >the leads back over the component on opposite sides. This creates an "S" >configuration with the component itself providing the structure and the >separation of the exposed leads. Then the whole thing is shrink-wrapped. Good idea! ________________________________________________________________________________
Date: Mar 09, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Switch numbering
> >Bob, > >I'd just like to confirm switch numbering. Some of your drawings show >Microswitch toggle switches while others show your S700-2-XX switches. >It appears that the numbering differs between the two sources. > >I have concluded that the numbering (with the keyway up viewed from the >back) is 1-2-3 bottom to top on the left and 4-5-6 bottom to top on the >right for the S700-2-XX and for the Microswitch the left and right >numbering is interchanged or 1-2-3 bottom to top on the right and 4-5-6 >bottom to top on the left. > >Is this correct? Another builder asked about this a short time ago. Here's the exchange . . . > >Bob, > Regarding figures Z-23 and Z-24, is there a typo on the pin numbers >for the S700-2-10 switch? I looked through the archives and couldn't >find any mention of errors, so if it's correct, please explain what's >different that reverses the pin 2 and pin 5 logic between these drawings Good eye. I thought I'd caught all those. Numbering shown in figures Z-23 and Z-24 are incorrect. I got wrapped around a manufacturing differences axle a few years ago when I discovered that my S700-2-10 switches were assembled opposite the Microswitch equivalents. Note the view of switch in Figure 11-11 versus switch view in Z-16. The columns are switched. Figure 11-11 is Microswitch; figure Z-16 is S700-2-10. I had published some variations on switch terminal numbering based on switches I was holding in my hand at the time not realizing there were two configurations. Sooooo . . . you've found a couple of artifacts in my wiring symbols that represent two switches with swapped functionality from side to side. I determined that the schematics could be left constant with respect to terminal numbers if I simply pointed out the difference between the two switches. I illustrated the S700-2-10 right on the drawing. The Microswitch product has reversed column numbers molded into the plastic switch housing. I've marked the switches in Figures Z-23/24 for correction. Thanks! Bob . . . ________________________________________________________________________________
Date: Mar 09, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: mounting inline components
> > > > Where do you need to drop a voltage just 0.6 volts and why? > > You really have my curiosity stoked here . . . > >I am putting camera mounts in the wings, and the camera is designed for 12 >volts, and the manufacturer suggested putting a couple of diodes in series >in front of the camera power to drop the 14v down a bit, which made sense >to me. The nominal current draw is 180 ma, so heat is not a >problem. Pictures of the mount and the camera fixture are on the >instrument and wings pages of www.liming.org/ch801. Interesting. If the cameras are THAT sensitive to input voltage, you might want to consider some form of low-dropout regulator. Your bus voltage can be anything from 13.8 to 14.6 volts and still be okay for operating the rest of the airplane. National makes a low-dropout regulator that works down to 0.5 volts of headroom. See: http://www.national.com/ds/LM/LM2940.pdf Bob . . . ________________________________________________________________________________
Date: Mar 09, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Vans tach sender
> > > >Anybody know how Vans tach sender works (the one that plugs into the tach > >drive on the accessory case and is then wired up to their tach > >gauge)? I'm wondering if it is a frequency generator of some sort that > >might be compatible with the Grand Rapids EIS 4000 engine monitor (which > >is designed to pick up pulses from a mag P lead). I asked Vans about it > >and haven't received any response. I'd rather use a pickup off the tach > >drive so that I don't have to depend on one ignition source or the other > >to get rpm (or use a switch between the two mags when doing a mag check). > >--Mark Navratil > >I can make a guess that it might be what used to be referred to as a tacho >generator. Simply a DC generator the voltage of which depends only on rpm. >I have an old one in a box somewhere in my shop. There used to be a Carr >(?) tacho that worked the same way. It had a nice 270 degree display. These can come in ALL flavors depending on the tachometer technology chosen by the people who designed the tach. I've built perhaps a dozen tachometer systems with "senders" that ranged from a (1) simple reed switch mounted in close proximity to a spinning magnet to (2) a hall-effect sensor that watches a dozen tiny bar magnets fly by to (3) variable reluctance pickup that watches gear teeth in a gear box, to etc, etc. There's no such thing as a standard tach transducer. It's unlikely that the signal from Van's tach would come even close to interfacing to the EIS4000 . . . magneto's put out two signal cycles per engine revolution. To make a tach work smoothly, you want as many pulses per revolution as possible . . . working with so few as 2/rev is tricky and why many magneto based tachs have problems. If an interface were to be designed for this task, I'd probably use what is called a phase-locked loop oscillator and frequency multiplier to make the 2/rev mag output match whatever the EIS4000 expects to see. I could build sufficient inertia and filtering into the interface to make the most skittish digital display settle down. Whatever the answer to this problem, it is not simple. ------------------ There has been a continuing thread about both errors in the tachometer and effects of RF on the tachometer and manifold pressure gauge. I have read several posts reporting tachometer errors and indicator changes when transmitters are keyed. My question is: Does anyone with these instruments have good results? Has the tachometer been calibrated and found within reasonable tolerances (+-10%?)? Has anyone's installation been immune to RF. That is unaffected when your transmitter is keyed? +/- 1% is a better goal . . . in fact, with modern technologies, 0.1% is easily attained. A very common problem with many of these products is the lack of understanding and/or willingness of their producers to address rudimentary aircraft systems interface problems. Airplanes carry VHF and UHF signal sources that can upset otherwise well behaved electronics. Over the years, I've probably made a dozen offers to companies to assist in making their products more bullet proof. These offers are generally triggered by some builder's effort to make the accessory perform well in his airplane. To date, not one company has taken me up on an offer of free assistance and many of you are still plagued with having to do their homework for them. I've suggested many times on this list and others that product performance SHOULD be marketplace driven. It matters not what the manufacturer's sales hype claims nor what blessings from Washington have been bestowed on the device. You folks have the ultimate ability to make purveyors of poor merchandise toe the line. It shouldn't matter how many "satisfied customers" the manufacturer claims . . . if it's not working in YOUR airplane, it's HIS problem and he should either make it work or give you your money back. Again, if any of you encounter system integration problems with a product and the manufacturer's tech support is having you fiddle with lots of changes or additions to the system that were NOT covered in his installation manual or advertising brochures, feel free to give them my e-mail address. I'd really like to see all this stuff work right out of the box . . but if it doesn't and they won't make the effort to fix it right . . . then you guys need to pass the word and hit the turkeys in their bottom line. Bob . . . ________________________________________________________________________________
Date: Mar 09, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Avionics cooling requirements
Bob, I have a Garmin GNS430 and GTX327 which each has a nipple for air, which leads me to think maybe it is required. (Above the 430 is a small audio panel). For the sake of argument, let's say I want to ALWAYS have a fan ON when the avionics are ON. Two questions: 1) how much volume is needed and can volume be translated to electrical power? 2) Does it matter if the volume is forced in, or pulled out (suction)? If suction would work, I would want to use the exhaust in place of a windshield defroster blower; see any problems with this? I live in the North, but have to plan for some trips to Texas and Florida. I will appreciate your comments. Thanks, Tom Barnes -6 electrical > >I have the GNS 430 and a King KT-76C transponder that require air cooling. I >have installed the Ameri-KingAK-920 cooling fan. It comes on with the >avionics switch and has worked great for the last 2 yrs. I live in Florida >and would not be without some source of cooling. >John The safest thing for ANY manufacturer or systems integrator to advise is, "If the critter has a cooling air inlet, blow into it." Without proper instrumentation on the item's hot spots inside, you have no way to evaluate whether or not your particular set of radios are having heating problems. My distributor lists a variety of avionics cooling blowers with 1 to 5 hose connections ranging from $125 to $250. Bob . . . ________________________________________________________________________________
Date: Mar 09, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Thermocouple Switches
> >In a message dated 2/24/02 8:55:05 PM Eastern Standard Time, >khorton(at)cyberus.ca writes: > > > > I've just installed a Grand Rapids EIS 4000 engine monitor. They > > provide Fast-Ons to connect the EGT and CHT thermocouples to the > > wires going into the monitor. The wires to the monitor are > > theromcouple wire, matching the wire coming from the thermocouples. > > > > Why are Fast-Ons a bad idea? Does a bit of corrosion at the > > interface between the male and female Fast-Ons eventually screw up > > the accuracy? > > > > What should be used instead of Fast-Ons? I'd like something that is > > removable, so I can simply unplug rather than pulling the probes if > > I ever need to pull the engine. > > > > Thanks, > > > > Kevin Horton > > > >Bob, >I guess I missed your reply to Kevin's question. Could you repeat your >answer? >Dale Ensing Hadn't answered it yet. I've been trying to come up with an answer he's going to like but I'm not sure that's possible. I guess EIS has been using fast-ons in their thermocouple leads for years . . and if they're still doing it, I must assume the customers are happy with how the system is working. IF I were to tackle this task on my airplane, here's how I'd do it: Hopefully the thermocouple wires are 20AWG or smaller. I'd use D-sub connectors with machined pins to make the interface with individual probes and a harness that brings all temperature data into the cabin. The harness needs to be fabricated from the same kind of thermocouple wire as the probe (type J or K). I'd bring the bundle to a small enclosure mounting a two pole, x-position switch for the purpose of selecting one-of-x thermocouples for display. Use another d-sub connector at the rear of the enclosure to bring the probe bundle into the switch and carry the thermocouple signal away to the instrument. The interior of the switch box can be wired with ordinary copper . . . when both sides of the thermocouple lead are treated with the same "interfering influence", the errors cancel out. Thermocouple wire is used to take the signal from the switch box to the instrument. http://38.254.60.87/embrace/IMAGES/PDF/f-45-50.pdf Grayhill has a suitable, miniature switch that you can view at the above link. This isn't an "easy" answer . . . it's a 2-4 hour project to assemble and wire it. Bob . . . ________________________________________________________________________________
From: "Keith Hughes" <rv6tc(at)earthlink.net>
Subject: big fuses
Date: Mar 09, 2002
Bob, In most schematics, there is a large CB/fuse that protects the B-lead off the Alternator. I can't figure out how to wire a CB without bringing a big wire up to the instrument panel. So, is the protection needed or will the crowbar OV relay suffice? Where can I get an inline fuse that will work? And, how do you wire that to a big 4AWG wire? Thanks. Keith RV-6 finish Denver ________________________________________________________________________________
Date: Mar 09, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Airline power sources
> > (Sorry this is getting SO LONG.. but there is lots to cover here!) Bob >answered my question with a couple of URLs that took me to some nice photos >of devices that looked like some ICs on a heat sink, but no information on >how or where to buy one, nor the circuit to build one. > > http://209.134.106.21/temp/apc15-14b.jpg > > That's one of them. An 'adjustable power conditioner'. > >That's pretty big for what I need! And I would need the circuit for that >thing anyway. When I posted those links, I thought I mentioned that the photos were of prototype devices about to be included on our website catalog and mentioned further that they would be priced about the same as dimmers of the same size. Data on a suitable device and info on wiring it can be found in: http://www.national.com/ds/LM/LM150.pdf diagram is in upper left corner of page 7. The prototype device I illustrated is actually SMALLER than what you need. I have an HP laptop that runs from a 19v, 2A power supply. I ran the battery down and then plugged a bench supply into the external DC power jack. The computer draws just over 2A just to charge the battery and the draw stayed over 1A for about 30 minutes. When I turned the computer on, the current draw went back up to 2A and stayed there until the battery finished charging. Then, depending on whether or not drives were spinning, the computer would draw between .8 and 1.8 amps. If you're going to toss away 9 volts at 2A you need to dump 18 watts. The little heatsink in: http://209.134.106.21/temp/apc15-14b.jpg will not let you do that continuously for very long. a heatsink capable of taking care of this dissipation is shown at: http://209.134.106.21/temp/MVC-008X.JPG >If I could find the correct plug, I could wire it to a small device that >takes in 28vdc and outputs 19vdc for a computer! > >WHERE could I find a device that does just that? Converts 28vdc to 19vdc, >no matter what the load on the user end? And, could I get one that doesn't >care too much what the input voltage is? I'd like to get one that takes in >12vdc-28vdc and puts out a constant 19vdc! This is also possible but probably beyond the scope of amateur workbench construction. It requires a special wound transformer and a handfull of electro-goodies. > >What does that look like? Is it nice a small and lightweight so I can carry >it on every trip? I could also use it on my computer in my car! > > Sorry this got so long... but I STILL need the answer: I'm reluctant to >plug anything that's labeled 50/60hz input into a 400hz outlet, so I want to >go with the 28VDC source. How can I do that, what do I need, and where can I >get it? If you have a 115vac outlet available, it's probably okay wiht your laptop power supply. Drop by an avionics shop and see if they'll let you power the supply from their 115vac/400Hz bench supply. Hold it in your hand and if it's no warmer in 15 minutes than it would be plugged into the wall, it's okay. My HP powersupply runs happily on 400Hz. -------------------- Suppose your laptop wants an amp at 19V - this seems typical. The three terminal regulator will accurately drop the 28V to 19V by inserting a sort of dynamicly adjusting resistor (actually transistor ) in line with the current. This resistor will generate heat. How much heat? P ( power ) equals E ( voltage ) times I(current). E here is the voltage DROP across the regulator. 28V - 19V = 9 volts. Current is an amp. Power is 9V times 1 amp, or 9 Watts. So you'll need a heat sink, which porks up the package somewhat, although 9 watts isn't all THAT much. I think most laptops are going to be in the 2-3 amp range at 19v. . . . more than 9 watts to dump You might be able to minimize the heatsink requirements by putting a series diode string before the input to the 3-terminal regulator. Each diode drops .7 volts. You should really have 5 volts of head room for the regulator, which means you want a minimum of 24 volts at its input. If you know what the minimum voltage output of the socket is, you subtract 24 volts from that, divide by .7V per diode, and then you come up with how many diodes to put in the string. If you tweek the design for 5V headroom, then your regulator only has to dissipate 5 watts instead of 9. But you still have to get rid of a total of 18w . . . whether it's with resistors, diodes or transistors, all of those goodies are going to dump out BTU's in trade for watts. The heat has to go somewhere. The best thing to do with it is dump to some device designed to maximize dissipation of the heat to surrounding atmosphere . . . i.e. something with fins or perhaps a fan on it. A totally enclosed, three-terminal circuit could perhaps be smaller by using forced air from a small fan . . . a tiny amount of air movement can have a profound effect on heatsink requirements. There are some really cute little fans out there used inside computers. Bob . . . ________________________________________________________________________________
Date: Mar 09, 2002
From: Kevin Horton <khorton(at)cyberus.ca>
Subject: Re: Thermocouple Switches
> > >> >>In a message dated 2/24/02 8:55:05 PM Eastern Standard Time, >>khorton(at)cyberus.ca writes: >> >> >> > I've just installed a Grand Rapids EIS 4000 engine monitor. They >> > provide Fast-Ons to connect the EGT and CHT thermocouples to the >> > wires going into the monitor. The wires to the monitor are >> > theromcouple wire, matching the wire coming from the thermocouples. >> > >> > Why are Fast-Ons a bad idea? Does a bit of corrosion at the >> > interface between the male and female Fast-Ons eventually screw up >> > the accuracy? >> > >> > What should be used instead of Fast-Ons? I'd like something that is >> > removable, so I can simply unplug rather than pulling the probes if >> > I ever need to pull the engine. >> > >> > Thanks, >> > >> > Kevin Horton >> > >> >>Bob, >>I guess I missed your reply to Kevin's question. Could you repeat your >>answer? >>Dale Ensing > > Hadn't answered it yet. I've been trying to come up > with an answer he's going to like but I'm not sure > that's possible. > > I guess EIS has been using fast-ons in their thermocouple > leads for years . . and if they're still doing it, I > must assume the customers are happy with how the system > is working. > > IF I were to tackle this task on my airplane, here's how > I'd do it: > > Hopefully the thermocouple wires are 20AWG or smaller. > I'd use D-sub connectors with machined pins to make > the interface with individual probes and a harness that > brings all temperature data into the cabin. > > The harness needs to be fabricated from the same > kind of thermocouple wire as the probe (type J or K). > > I'd bring the bundle to a small enclosure mounting > a two pole, x-position switch for the purpose of > selecting one-of-x thermocouples for display. > > Use another d-sub connector at the rear of the enclosure > to bring the probe bundle into the switch and carry the > thermocouple signal away to the instrument. > > The interior of the switch box can be wired with > ordinary copper . . . when both sides of the > thermocouple lead are treated with the same > "interfering influence", the errors cancel out. > > Thermocouple wire is used to take the signal > from the switch box to the instrument. > > http://38.254.60.87/embrace/IMAGES/PDF/f-45-50.pdf > > Grayhill has a suitable, miniature switch that you > can view at the above link. > > This isn't an "easy" answer . . . it's a 2-4 hour > project to assemble and wire it. > > Bob . . . > Hmm. I getting very confused. My original question was in regard to using Fast-Ons to join thermocouple wires with the wires going into my EIS 4000. Now Bob is talking about switches. The EIS 4000 doesn't use any switches, as all thermocouple wires go into the unit, and it can display data from all cylinders at once. The wires from the Fast-Ons to the EIS 4000 are thermocouple wires, i.e. type J or K as appropriate. Looking at one wire, I see the following interfaces in order: Type J wire from thermocouple to male Fast-On tab; male Fast-On tab to female Fast-On tab; female Fast-On tab to Type J wire; Type J wire to male D-sub pin; male D-sub pin to female D-sub pin (connector attached to the back of the EIS). I can't tell what kind of wire is used from here on in. The parts I'm worried about are those associated with the Fast-On tabs. Everytime we have an interface with dissimilar metals, we'll create a voltage. The voltages at the two interfaces between the Type J wire and the Fast-On tabs will cancel each other out, assuming both interfaces are the same temperature. So I don't see how using Fast-On tabs creates a problem, but I'm certainly no expert, so I could have this all messed up. Kevin Horton ________________________________________________________________________________
From: "Matthew Mucker" <matthew(at)mucker.net>
Subject: big fuses
Date: Mar 09, 2002
Keith, The crowbar protects against overVOLTAGE. The CB protects against overCURRENT. They're not interchangable. But I'm sure Bob will elaborate on that. :) -Matt > In most schematics, there is a large CB/fuse that protects the B-lead off > the Alternator. I can't figure out how to wire a CB without > bringing a big > wire up to the instrument panel. So, is the protection needed > or will the > crowbar OV relay suffice? Where can I get an inline fuse that will work? > And, how do you wire that to a big 4AWG wire? > Thanks. ________________________________________________________________________________
Date: Mar 09, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Thermocouple Switch for Blue Mountain EFIS
Kevin Says: Hmm. I getting very confused. My original question was in regard to using Fast-Ons to join thermocouple wires with the wires going into my EIS 4000. Now Bob is talking about switches. The EIS 4000 doesn't use any switches, as all thermocouple wires go into the unit, and it can display data from all cylinders at once. Bob Says: I can see why. I'd been mulling over an answer to an earlier question by Craig that started something of a tread on thermocouples. I got several questions stirred together in the reply which I have split out as follows: Craig Asked: I'm working on connecting up my EFIS/One from Blue Mountain Avionics into my existing airplane. I'm looking for a special switch (or suggestions), connecting my EGT/CHT sensors to the system. The EFIS has 6 inputs for thermocouples, and I have a 6 cylinder Lyc. So I was gonna put my 3 hottest cylinders, both EGT & CHT (for a total of 6 inputs), and then use a (and this is where I need the help), a 6 way (6PDT on-on switch - if there is such a thing). Then I would switch from my 3 hottest cylinders, which I want to monitor most of the time, and to check the others as needed. If anyone has a better suggestion, let me know. By the way, I've seen Bob's thermocouple information in Chap 14 of the current Aeroelectric Connection. IF I were to tackle this task on my airplane, here's how I'd do it: Put the 2 hottest cylinder CHT/EGT thermocouples onto 2 fixed inputs which uses up 4 of the total. Run the other pair of inputs to a 4-pole, 4-position such that thermocouple PAIRS for the other 4 cylinders can be switched to the "roving" inputs to the EFIS. Hopefully the thermocouple wires are 20AWG or smaller. I'd use D-sub connectors with machined pins to make the interface with individual probes and a harness that brings all temperature data into the cabin. The harness needs to be fabricated from the same kind of thermocouple wire as the probe (type J or K). I'd bring the bundle to a small enclosure mounting a two pole, x-position switch for the purpose of selecting one-of-x thermocouples for display. Use another d-sub connector at the rear of the enclosure to bring the probe bundle into the switch and carry the thermocouple signal away to the instrument. The interior of the switch box can be wired with ordinary copper . . . when both sides of the thermocouple lead are treated with the same "interfering influence", the errors cancel out. Thermocouple wire is used to take the signal from the switch box to the instrument. Grayhill has a suitable, miniature switch that you can purchase from Digikey goto: http://www.digikey.com and enter 71BD30-02-2-AJN as the part number to search. This switch has two decks of two poles each for a total of 4 poles. It has an adjustable stop so that you can limit the throw to 4 positions. Bob . . . ________________________________________________________________________________
Date: Mar 09, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Thermocouple and fast-ons
Kevin says: Hmm. I getting very confused. My original question was in regard to using Fast-Ons to join thermocouple wires with the wires going into my EIS 4000. Now Bob is talking about switches. The EIS 4000 doesn't use any switches, as all thermocouple wires go into the unit, and it can display data from all cylinders at once. Bob says: I see how I got it muddied up. There were a couple of thermocouple questions I was treating as a thread. I've split them apart and we'll work with Kevin's question. The wires from the Fast-Ons to the EIS 4000 are thermocouple wires, i.e. type J or K as appropriate. Looking at one wire, I see the following interfaces in order: Type J wire from thermocouple to male Fast-On tab; male Fast-On tab to female Fast-On tab; female Fast-On tab to Type J wire; Type J wire to male D-sub pin; male D-sub pin to female D-sub pin (connector attached to the back of the EIS). I can't tell what kind of wire is used from here on in. The parts I'm worried about are those associated with the Fast-On tabs. Everytime we have an interface with dissimilar metals, we'll create a voltage. The voltages at the two interfaces between the Type J wire and the Fast-On tabs will cancel each other out, assuming both interfaces are the same temperature. So I don't see how using Fast-On tabs creates a problem, but I'm certainly no expert, so I could have this all messed up. Kevin, My concern with fast-ons is based on the relative harness of the two materials. Thermocouple wire is quite hard compared to the terminal that's grabbing it and trying to get a gas-tight joint. I prefer the machined pins found available for D-subs and other multi-pin connectors for their 4-quadrant grip on the wire. EIS has been using the fast-ons for years and I must presume they're getting satisfactory service . . . so I'd advise that you follow their instructions and truck on. Bob . . . ________________________________________________________________________________
Date: Mar 09, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: big fuses
> >Bob, > >In most schematics, there is a large CB/fuse that protects the B-lead off >the Alternator. I can't figure out how to wire a CB without bringing a big >wire up to the instrument panel. So, is the protection needed or will the >crowbar OV relay suffice? Where can I get an inline fuse that will work? >And, how do you wire that to a big 4AWG wire? >Thanks. Have you looked over the articles on our website at http://www.aeroelectric.com ??? All of these questions and many more are answerable for the downloading time . . . You might also consider acquiring a copy of The AeroElectric Connection which can be ordered from the same website. If you have a slow internet connection, you can get a mirror image of the website on a CD ROM that will save a lot of download time. Take a peek too at the range of tools and materials available from both website catalogs at http://www.aeroelectric.com/Catalog/AECcatalog.html and http://www.aeroelectric.com/Catalog/BCcatalog.html The descriptive literature for these products are a good education as to what's available and how they are used. Bob . . . ________________________________________________________________________________
From: "Craig Snively" <craigsn(at)hotmail.com>
Subject: Re: Thermocouple Switch for Blue Mountain EFIS
Date: Mar 09, 2002
Thanks for the suggestion Bob. I like this idea best of all that I've seen so far. Craig > IF I were to tackle this task on my airplane, here's how > I'd do it: > > Put the 2 hottest cylinder CHT/EGT thermocouples onto > 2 fixed inputs which uses up 4 of the total. ________________________________________________________________________________
From: "Gabriel A Ferrer" <ferrergm(at)bellsouth.net>
Subject: B&C's LR3 Voltage Regulator
Date: Mar 09, 2002
I bought the B&C LR3 Voltage Regulator. The following installation instruction was included: "Be sure to use a 5 amp circuit breaker on pin 6 of the regulator. Connecting pin 6 directly to the bus or using so called "solid-state breakers (PTC thermistors) will damage the regulator if there is an overvoltage trip" My RV6 electrical installation includes Control Vision's ExpBus. It has a 5 amp "polyfuse" (thermal breaker) in series with the wire going to pin 6. 1. Will this create a problem for the voltage regulator? 2. If yes to 1: will installing a 5 amp in line fuse in series with the polyfuse correct the problem? 3. If no to 2: what do you recommend? (too late to return the ExpBus) Gabe A Ferrer (RV6, working on installing electrical system) Cell: 561 758 8894 Voice or Fax: 561 622 0960 Email: ferrergm(at)bellsouth.net ________________________________________________________________________________
From: "Keith Hughes" <rv6tc(at)earthlink.net>
Subject: Re: big fuses
Date: Mar 09, 2002
Yes, I have a copy of the AeroElectric Connection. I also checked your website and didn't find any specifics. I must have missed it. Keith . > > > Have you looked over the articles on our website at > http://www.aeroelectric.com ??? > > . . . You might also > consider acquiring a copy of The AeroElectric > Connection ________________________________________________________________________________
From: "John Harlow" <jharlow(at)onearrow.net>
Subject: Re: B&C's LR3 Voltage Regulator
Date: Mar 10, 2002
Gabe, I also have the EXP buss and when I discovered the same information re the 5 amp fuse, I called B&C and they informed me include a 5 amp CB in series. The EXP buss always has a residual voltage going through it and must have the power shut down for it to reset. B&C also told me that the mechanical CB is quicker and they wanted it installed for warranty reasons. John Have a GREAT day!!! ----- Original Message ----- From: "Gabriel A Ferrer" <ferrergm(at)bellsouth.net> Subject: AeroElectric-List: B&C's LR3 Voltage Regulator > > I bought the B&C LR3 Voltage Regulator. The following installation > instruction was included: > > "Be sure to use a 5 amp circuit breaker on pin 6 of the regulator. > Connecting pin 6 directly to the bus or using so called "solid-state > breakers (PTC thermistors) will damage the regulator if there is an > overvoltage trip" > > My RV6 electrical installation includes Control Vision's ExpBus. It has > a 5 amp "polyfuse" (thermal breaker) in series with the wire going to > pin 6. > > 1. Will this create a problem for the voltage regulator? > > 2. If yes to 1: will installing a 5 amp in line fuse in series with the > polyfuse correct the problem? > > 3. If no to 2: what do you recommend? (too late to return the ExpBus) > > Gabe A Ferrer (RV6, working on installing electrical system) > Cell: 561 758 8894 > Voice or Fax: 561 622 0960 > Email: ferrergm(at)bellsouth.net > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Daniel Pelletier" <pelletie1(at)hotmail.com>
Subject: starter contactor
Date: Mar 10, 2002
Hi Bob, I'm confused again. I've yet a solenoid right on my starter. Some guys told me that I don't need starter contactor in that case and I've just to bring the battery cable (from Battery contactor) right on the big starter's stud and to plug the solenoid connection right on the start's pole of the ignition switch. Is that true. In the wiring's diagram, I saw that the main buss is wiring from the starter contactor. Where did I take my feed if I have not starter contactor, on the starter stud? Thanks for help. Daniel Pelletier 601 HDS Wiring http://messenger.msn.fr ________________________________________________________________________________
Date: Mar 10, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: big fuses
> >Bob, > >In most schematics, there is a large CB/fuse that protects the B-lead off >the Alternator. I can't figure out how to wire a CB without bringing a big >wire up to the instrument panel. So, is the protection needed or will the >crowbar OV relay suffice? Where can I get an inline fuse that will work? >And, how do you wire that to a big 4AWG wire? >Thanks. Have you looked over the articles on our website at http://www.aeroelectric.com? >Yes, I have a copy of the AeroElectric Connection. I also checked your >website and didn't find any specifics. I must have missed it. There are no specifics to your questions by title of the article but it's all in there. For example: >In most schematics, there is a large CB/fuse that protects the B-lead off >the Alternator. I can't figure out how to wire a CB without bringing a big >wire up to the instrument panel In Note 9 of Appendix Z (which I observe should be Note 10 to match the drawings) we talk about getting the b-lead feeder out the cockpit. In the chapter on noise, we discuss the value of keeping FAT wires (carry large currents and have strong, noisy magnetic fields around them) away from SKINNY wires (that carry radio and instrumentation signals). In all of our published power distribution diagrams, we show the alternator b-lead tied to the hot side of the starter contactor on the firewall. In Figures 17-1, 17-2 and associated text we discuss the rational for putting b-lead protection out on the firwall . . . whether fuse or circuit breaker - it doesn't matter. >Where can I get an inline fuse that will work? The current recommendation is illustrated at: http://www.aeroelectric.com/Catalog/ckrtprot/ckrtprot.html#bleadfuse and offered for sale at: http://www.aeroelectric.com/Catalog/BCcatalog.html >And, how do you wire that to a big 4AWG wire? Articles at: http://209.134.106.21/articles/big_term.pdf http://209.134.106.21/articles/rules/review.html http://209.134.106.21/articles/terminal.pdf speak to various issues and techniques surrounding soldered and crimped terminals including big fellers for fat wires to go on your battery master and starter contactors. Bob . . . ________________________________________________________________________________
Date: Mar 10, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: B&C's LR3 Voltage Regulator
> > >I bought the B&C LR3 Voltage Regulator. The following installation >instruction was included: > >"Be sure to use a 5 amp circuit breaker on pin 6 of the regulator. >Connecting pin 6 directly to the bus or using so called "solid-state >breakers (PTC thermistors) will damage the regulator if there is an >overvoltage trip" > >My RV6 electrical installation includes Control Vision's ExpBus. It has >a 5 amp "polyfuse" (thermal breaker) in series with the wire going to >pin 6. > >1. Will this create a problem for the voltage regulator? I've not taken the time to run any tests using the crowbar OV protection system with Polyswitches . . . The fault current that flows in the milliseconds after a OV condition is detected can be as high as 300 amps. This causes the 5A breaker to open right smartly. It is possible that the Polyswitch time delays are sufficiently longer under these conditions to put etched circuit board traces inside the LR3 regulator at risk. >2. If yes to 1: will installing a 5 amp in line fuse in series with the >polyfuse correct the problem? Yes, this is the most conservative approach to avoiding future problems. Bob . . . ________________________________________________________________________________
Date: Mar 10, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: RE: starter contactor
> > > >Hi Bob, > >I'm confused again. I've yet a solenoid right on my starter. Some guys told >me that I don't need starter contactor in that case and I've just to bring >the battery cable (from Battery contactor) right on the big starter's stud >and to plug the solenoid connection right on the start's pole of the >ignition switch. Is that true. You CAN use built in contactors included on MOST starters but you may not want to. See: http://209.134.106.21/articles/strtctr.pdf If you DO use a built in contactor and the starter is a wound field device (like B&C) then you can make your starter engagement switch last a whole lot longer by adding a buffer relay as shown in Figure Z-22 of the AeroElectric Connection. If you have a PM motor starter (like Skytech) then the buffer relay is REQUIRED to prevent starter run-on and to protect the starter switch's condtacts. >In the wirings diagram, I saw that the main buss is wiring from the starter >contactor. Where did I take my feed if I have not starter contactor, on the >starter stud? Of the switched side of the battery contactor . . . but if it were my airplane, it would have an auxiliary contactor like our 702-1 that has no heavy inrush currents, draws about 4 amps while energized, has built-in arc suppression diode on coil and provides a hand location on firewall for power distribution and b-lead feeds when the battery is located remotely from the engine. See: http://www.aeroelectric.com/Catalog/switch/switch.html#s702-1 Bob . . . ________________________________________________________________________________
From: BAKEROCB(at)aol.com
Date: Mar 10, 2002
Subject: fast ons for thermocouple wiring
In a message dated 03/10/2002 2:53:27 AM Eastern Standard Time, khorton(at)cyberus.ca writes: << ....skip..... Hmm. I getting very confused. My original question was in regard to using Fast-Ons to join thermocouple wires with the wires going into my EIS 4000. Now Bob is talking about switches. The EIS 4000 doesn't use any switches, as all thermocouple wires go into the unit, and it can display data from all cylinders at once. The wires from the Fast-Ons to the EIS 4000 are thermocouple wires, i.e. type J or K as appropriate. Looking at one wire, I see the following interfaces in order: Type J wire from thermocouple to male Fast-On tab; male Fast-On tab to female Fast-On tab; female Fast-On tab to Type J wire; Type J wire to male D-sub pin; male D-sub pin to female D-sub pin (connector attached to the back of the EIS). I can't tell what kind of wire is used from here on in. The parts I'm worried about are those associated with the Fast-On tabs. Everytime we have an interface with dissimilar metals, we'll create a voltage. The voltages at the two interfaces between the Type J wire and the Fast-On tabs will cancel each other out, assuming both interfaces are the same temperature. So I don't see how using Fast-On tabs creates a problem, but I'm certainly no expert, so I could have this all messed up. Kevin Horton >> 3/10/2002 Hello Kevin (and Bob), I think that Bob has now responded and sorted out any switch confusion, but I'd like to pursue this subject a bit further. What I'm going to describe is how Vision Microsystems Inc. handles their thermocouple inputs. It might give some confidence to what you are doing or uncover some subtle aspect of this subject that is of value. With the VMS system I got 4 EGT and 4 CHT thermocouples already lead wired with appropriate K and J wires that terminated in 1/4 inch wide male / female push-ons. (I'm using the generic term "push-on" here because Fast On is a proprietory AMP name and the distinction may be important to some people). VMS provides more J and K wire for transition and some Thomas and Betts fully insulated push-ons that just get crimped onto the transition wire for connecting to the push-on on the end of the lead wire coming from the thermocouple. (I declined to use the provided T&B push-ons and purchased fully insulated Molex Avi Krimp push-ons because the Avi Krimp push-ons have the additional metal wire insulation crimping support and the T&B's did not). The J and K transition wires then go to a 25 pin D sub connector (in the newer version of the VMS DPU (Data Processing Unit) which plugs into the DPU. The D sub connector has stamped pins and the the transition wires are both crimped and soldered to these pins. VMS makes a big deal of the fact that one must use the special soldering flux that they supply. I quote: "Apply NOKORODE flux to these leads, otherwise the solder will not bond to the wire properly. NOTE:Read caution statements and direction on container before use)". NOKORODE Regular Paste Flux is made by Rectorseal in Houston TX. It contains zinc chloride, but no lead. It is described as "Not for electronics use.....". It needs to be washed off with water after soldering. It is a little puzzling to me as to why the wires must be soldered to the D sub pins, but just crimping them to the push-ons on the other end is OK. It would not be possible to solder to the push ons that VMS provided or the ones that I used because of the insulation. Also I believe that the push-ons on the end of the thermocouple lead wires were soldered on by the factory that produced the thermocouples and the leads. (I can't easily check because the leads are now all covered up in wire looms.) This crimp only versus crimp plus soldering at the push-on junction would seem to create an asymmetry and generate some erroneous signal. Maybe some expert reading this can explain away my concern. The output from the DPU to the LCD VMS guages is via ribbon cable. So, with the exception of the soldering bit, it looks like you are doing what VMS considers good practice. You might want to call VMS up (ask for Dave) and discuss the pin soldering issue. Their number is 360-714-8203. Yes, I know that you are not using their product, but they have always been very generous in educating me. Good luck. 'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - ?/?/? PS: The thermocouple leads in the Westach (800-400-7024) catalog are terminated with push-on connectors. They make the statement that thermocouple leads (which are offered in a variety of lengths) should not be cut. But they also show patch (transition) cables leading to the instruments which may be shortened or lengthened. The catalog doesn't say anything specific about connecting patch cables to the instruments. Maybe a phone call to them would be educational. Please share what you learn with the rest of us. Thanks. ________________________________________________________________________________
Date: Mar 10, 2002
From: Charlie Kuss <chaskuss(at)bellsouth.net>
Subject: Re: EGT/CHT channel scanner was Re: AeroElectric-List:
Re: Thermocouple Switches >snipped > IF I were to tackle this task on my airplane, here's how > I'd do it: > > Hopefully the thermocouple wires are 20AWG or smaller. > I'd use D-sub connectors with machined pins to make > the interface with individual probes and a harness that > brings all temperature data into the cabin. > > The harness needs to be fabricated from the same > kind of thermocouple wire as the probe (type J or K). > > I'd bring the bundle to a small enclosure mounting > a two pole, x-position switch for the purpose of > selecting one-of-x thermocouples for display. > > Use another d-sub connector at the rear of the enclosure > to bring the probe bundle into the switch and carry the > thermocouple signal away to the instrument. > > The interior of the switch box can be wired with > ordinary copper . . . when both sides of the > thermocouple lead are treated with the same > "interfering influence", the errors cancel out. > > Thermocouple wire is used to take the signal > from the switch box to the instrument. > > http://38.254.60.87/embrace/IMAGES/PDF/f-45-50.pdf > > Grayhill has a suitable, miniature switch that you > can view at the above link. > > This isn't an "easy" answer . . . it's a 2-4 hour > project to assemble and wire it. Bob, What you suggest seems like a more elegant version of what RMI suggests for monitoring multiple CHT/EGTs on their Micro Monitor. I have a Micro Monitor (got it used at a very good price). This solution works, however, it does not allow maximum use of one very useful feature available in nearly every engine monitoring system.... the out of limit alarm. These alarm features, allow the pilot to keep his head outside the aircraft. With the alarm, I know that I don't HAVE to watch the EGTs and CHTs during cruise flight. The alarm will warn me if a cylinder starts running to hot (or cold). My Micro Monitor only allows me to monitor one EGT and one CHT at a time. Even with a rotary switch, I can only monitor one cylinder at a time (usually the hottest one). I feel that there is a weak point in the use of a rotary switch to view the other cylinders. I am forced to choose between constantly operating the rotary switch to check the other cylinders. This defeats the whole purpose of the engine monitor: allowing me to concentrate on watching for traffic. The other choice is to leave the rotary switch positioned on the hottest cylinder with occasional checks of the other cylinders (Every 5-10 minutes). I would like to install an electronic switching and scanning device between the 4 CHT & 4 EGT probes of my engine and the 2 inputs of my engine monitor. A device that would scan each channel for a predetermined amount (adjustable?) of time, then repeat for the next three channels. This would allow the alarm to catch any fault much sooner than I would catch it. A vacuum leak in one intake runner or a partially clogged fuel injector could easily cause the mixture to go lean. Thus a normally cool cylinder would start running hot. A bad ignition wire or plug would cause the effective timing (running with only one spark source) to retard. This would also cause a rise in CHT and/or EGT temps on the effected cylinder(s). While these are not "everyday" occurrences, at $20,000+ for a new engine, I hate to take unnecessary chances. Is such a module commercially available? Could one be built reasonably? Charlie Kuss RV-8A fuselage Boca Raton, Fl. ________________________________________________________________________________
From: "Ronnie Brown" <romott(at)adelphia.net>
Subject: Re: Vans tach sender
Date: Mar 10, 2002
My EIS 4000 manual says it can handle 1, 1.5, 2, 3, 4, 5, 6, 7, 8, or 9 pulses per revolution. A friend of mine has an RV6 with a tach pulse generator that he bought from Aircraft Spruce which plugs into the tachometer cable connection on the engine that interfaces with his EIS. Ronnie Brown ________________________________________________________________________________
From: HCRV6(at)aol.com
Date: Mar 10, 2002
Subject: Contactor confusion
Hi Bob: I have a B&C master contactor and a four terminal starter contactor of the type that has two small terminals labeled "S" and "I." After rereading your book and several of your articles I got curious about the internal connections on these devises and started checking with my multimeter and found that I measure essentially zero resistance through the coils of both devises where your book and related articles says there should be somewhere between 4 and 15 ohms (all diodes and connections removed). Can you help me understand what is going on here? Both devises pull in properly when I apply 12 volts across the coil terminals. Also, what is the "I" terminal on the starter contactor connected to? Van's suggested wiring diagram shows an optional lightweight starter hookup that has a jumper from the "I" terminal on the contactor to the starter solinoid. Any idea what that is for (I am using your Z-1, now Z-11 wiring but am unsure how to treat the Sky-Tec starter on my new engine)? Thanks for you continuing support and patience with these probably dumb questions. Harry Crosby Pleasanton, California RV-6, wiring ________________________________________________________________________________
Date: Mar 10, 2002
From: Kevin Horton <khorton(at)cyberus.ca>
Subject: PVC insulation - EIS 4000
I've just started the installation of a Grand Rapids EIS 4000 engine monitor in my RV-8. I had assumed that all the wiring would have aircraft quality tefzel installation, but I just learned that the harness going into the unit have PVC insulation. So now I have some thinking to do. First I must decide how much of the wiring I will replace, and then I must convince the Canadian inspector of the correctness of my plan. I'll contact the inspector as soon as I have done my thinking and have a convincing story. If he is going to insist on a major rewiring I would rather know now before I get too deep into this. I need to acquire some knowledge on PVC insulation. I assume there are three potential issues: 1. Noxious fumes if the insulation is overheated (yes, I agree that no wires in a properly designed and installed electrical system should ever overheat. However, we still read about the occasional electrical smoke or fire incident, even on type certificated aircraft); 2. Abrasion resistance not as good as tefzel insulation; and 3. Shorter life than tefzel insulation. Tackling these issues in order: 1. I assume that PVC insulation on some wires is OK, as not all wires are at risk of getting hot. I could use PVC insulation as long as the wires in question are routed well clear of the exhaust system, handle low voltage/low power signals (i.e. CHT and EGT extension wires) and are not in the same bundle as wires with power sources. Are these criteria reasonable? 2. Assuming the wires in question are well secured and cannot chafe against anything, are there any other abrasion issues to worry about? 3. How does the life of PVC insulation compare to tefzel? What failure modes should I expect as the wire ages? What warning signs should I look for? Thanks for your assistance, -- Kevin Horton RV-8 (installing engine) Ottawa, Canada http://eccentrix.com/misc/rv8/rv8.html ________________________________________________________________________________
From: "Ed Perry" <eperry(at)san.rr.com>
Subject: Re: PVC insulation - EIS 4000
Date: Mar 10, 2002
Kevin, I would say that you should talk to the EIS people. They have been very helpful to me. I am sure you are not the first to try a Canadian installation of their system, maybe they know the answers. You should definitely at least send them a copy of your e-mail to the group with your concerns. Good luck, Ed Perry eperry(at)san.rr.com ----- Original Message ----- From: "Kevin Horton" <khorton(at)cyberus.ca> Subject: AeroElectric-List: PVC insulation - EIS 4000 > > I've just started the installation of a Grand Rapids EIS 4000 engine > monitor in my RV-8. I had assumed that all the wiring would have > aircraft quality tefzel installation, but I just learned that the > harness going into the unit have PVC insulation. > > So now I have some thinking to do. First I must decide how much of > the wiring I will replace, and then I must convince the Canadian > inspector of the correctness of my plan. I'll contact the inspector > as soon as I have done my thinking and have a convincing story. If > he is going to insist on a major rewiring I would rather know now > before I get too deep into this. > > I need to acquire some knowledge on PVC insulation. I assume there > are three potential issues: > > 1. Noxious fumes if the insulation is overheated (yes, I agree that > no wires in a properly designed and installed electrical system > should ever overheat. However, we still read about the occasional > electrical smoke or fire incident, even on type certificated > aircraft); > > 2. Abrasion resistance not as good as tefzel insulation; and > > 3. Shorter life than tefzel insulation. > > Tackling these issues in order: > > 1. I assume that PVC insulation on some wires is OK, as not all wires > are at risk of getting hot. I could use PVC insulation as long as > the wires in question are routed well clear of the exhaust system, > handle low voltage/low power signals (i.e. CHT and EGT extension > wires) and are not in the same bundle as wires with power sources. > Are these criteria reasonable? > > 2. Assuming the wires in question are well secured and cannot chafe > against anything, are there any other abrasion issues to worry about? > > 3. How does the life of PVC insulation compare to tefzel? What > failure modes should I expect as the wire ages? What warning signs > should I look for? > > Thanks for your assistance, > -- > Kevin Horton RV-8 (installing engine) > Ottawa, Canada > http://eccentrix.com/misc/rv8/rv8.html > > http://www.matronics.com/browselist/aeroelectric-list > > ________________________________________________________________________________
From: "Cy Galley" <cgalley(at)qcbc.org>
Subject: Re: PVC insulation - EIS 4000
Date: Mar 10, 2002
I'm sorry but PVC just isn't acceptable in aircraft period. The amount of money you might save is insignificant when you consider the PVC will crack and possible shortout. This will overheat it. Yes, you can get it in colors but simple wire markers work just as well. Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh Editor, EAA Safety Programs cgalley(at)qcbc.org or experimenter(at)eaa.org Always looking for articles for the Experimenter ----- Original Message ----- From: "Kevin Horton" <khorton(at)cyberus.ca> Subject: AeroElectric-List: PVC insulation - EIS 4000 I've just started the installation of a Grand Rapids EIS 4000 engine monitor in my RV-8. I had assumed that all the wiring would have aircraft quality tefzel installation, but I just learned that the harness going into the unit have PVC insulation. So now I have some thinking to do. First I must decide how much of the wiring I will replace, and then I must convince the Canadian inspector of the correctness of my plan. I'll contact the inspector as soon as I have done my thinking and have a convincing story. If he is going to insist on a major rewiring I would rather know now before I get too deep into this. I need to acquire some knowledge on PVC insulation. I assume there are three potential issues: 1. Noxious fumes if the insulation is overheated (yes, I agree that no wires in a properly designed and installed electrical system should ever overheat. However, we still read about the occasional electrical smoke or fire incident, even on type certificated aircraft); 2. Abrasion resistance not as good as tefzel insulation; and 3. Shorter life than tefzel insulation. Tackling these issues in order: 1. I assume that PVC insulation on some wires is OK, as not all wires are at risk of getting hot. I could use PVC insulation as long as the wires in question are routed well clear of the exhaust system, handle low voltage/low power signals (i.e. CHT and EGT extension wires) and are not in the same bundle as wires with power sources. Are these criteria reasonable? 2. Assuming the wires in question are well secured and cannot chafe against anything, are there any other abrasion issues to worry about? 3. How does the life of PVC insulation compare to tefzel? What failure modes should I expect as the wire ages? What warning signs should I look for? Thanks for your assistance, -- Kevin Horton RV-8 (installing engine) Ottawa, Canada http://eccentrix.com/misc/rv8/rv8.html http://www.matronics.com/browselist/aeroelectric-list ________________________________________________________________________________
From: "Gary Casey" <glcasey(at)gte.net>
Subject: Thermocouple connections
Date: Mar 11, 2002
<> I think there is too much worrying going on about TC connections. In the old days we used meters for temperature read-outs that were sensitive to circuit resistance, but these days the interface is a very high impedance electronic one. If the pair of connections is at the same temperature the error in reading should be very small, in my experience. In other words, if you connect the positive TC wire to a copper wire at the same location that the negative one is connected it will cancel out the TC effect of the connection. But if the positive one is connected, say, in the engine compartment and the negative goes into the cockpit before it changes to copper you can expect an error in reading roughly in the amount of the difference in temperature. I can't see where on flux will have an effect compared to another - or even crimped compared to soldered. Gary Casey ________________________________________________________________________________
From: "Gary Casey" <glcasey(at)gte.net>
Subject: Polyfuse
Date: Mar 11, 2002
<a 5 amp "polyfuse" (thermal breaker) in series with the wire going to >pin 6. > >1. Will this create a problem for the voltage regulator? I've not taken the time to run any tests using the crowbar OV protection system with Polyswitches . . . The fault current that flows in the milliseconds after a OV condition is detected can be as high as 300 amps. This causes the 5A breaker to open right smartly. It is possible that the Polyswitch time delays are sufficiently longer under these conditions to put etched circuit board traces inside the LR3 regulator at risk.>> Maybe I can help. The "Polyfuse" is an NTC device designed to have a very steep temperature curve. It is not a fuse as such, but is more correctly called a "current limiter." I use a Raychem Polyswitch to protect a .5 amp power supply against overload and the one I picked will limit at .35 amps at -40C and .11 amps at 85C so you can see there is a wide variation of the current limiting vs temperature. After tripping it will dissipate 1.1 watts at 25C, which means that it will continue to pass about .09 amps at 12 volts WITH A DEAD SHORT IN THE SYSTEM. It will not open, but will go from, in this case, a resistance of 4.8 ohms in the "conducting" mode to about 133 ohms with a dead short applied. Gary Casey ________________________________________________________________________________
Date: Mar 11, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Contactor confusion
> >Hi Bob: I have a B&C master contactor and a four terminal starter >contactor of the type that has two small terminals labeled "S" and "I." >After rereading your book and several of your articles I got curious about >the internal connections on these devises and started checking with my >multimeter and found that I measure essentially zero resistance through the >coils of both devises where your book and related articles says there should >be somewhere between 4 and 15 ohms (all diodes and connections removed). Can >you help me understand what is going on here? Both devises pull in properly >when I apply 12 volts across the coil terminals. The diodes shouldn't make any difference when measureing these devices with a multi-meter. What kind of multi-meter are you using? Some of the lower cost, analog devices don't have a good low ohms capability. For example, I have an old "pocket" mulitmeter that reads 1000 ohms at midscale on the lowest resistance setting. This means that 4-ohms and 15-ohms would look like zero ohms on the instrument. >Also, what is the "I" terminal on the starter contactor connected to? Van's >suggested wiring diagram shows an optional lightweight starter hookup that >has a jumper from the "I" terminal on the contactor to the starter solinoid. >Any idea what that is for (I am using your Z-1, now Z-11 wiring but am unsure >how to treat the Sky-Tec starter on my new engine)? Thanks for you >continuing support and patience with these probably dumb questions. The "I" terminal is essentially a second power output terminal that becomes hot when the contactor is energized. See http://www.aeroelectric.com/Catalog/switch/switch.html#s702-1 and http://www.aeroelectric.com/Catalog/switch/S702Wire.jpg The "I" terminal was used on automobiles to boost ignition coil primary current during cranking. This terminal could very well be used as Van suggests . . . it will serve the same function as the starter-run-on buffer relay shown in figure Z-22 of the book . . . The "I" terminal has been used by some builders to drive a STARTER ENGAGED light on the panel. Bob . . . -------------------------- TEMPORARY WEBSITE ADDRESS: http://209.134.106.21 -------------------------- ________________________________________________________________________________
Date: Mar 11, 2002
From: Shelby Smith <rvaitor(at)comcast.net>
Subject: Alternator Problem
Hi All, I just had a problem with my alternator and discovered the bracket holding it on was broken. In disassembling it I notice what I thought was a ground wire to the shielding was broken and not making contact. After reassembling I noticed the shielding(on the ground wire) was not grounded on the other side so I left it off. Now I noticed when I first was having a problem that my alternator was discharging. Well after replacing the bracket and reattaching the wires(hopefully correctly), I am still discharging. Before I remove the alternator and take it to be tested, do you think I could have replaced the two small wires incorrectly on the alternator? Could what I thought was a ground wire to the shielding been something else? Thanks for your help. Shelby Smith ________________________________________________________________________________
From: HCRV6(at)aol.com
Date: Mar 11, 2002
Subject: Re: Contactor confusion
In a message dated 3/11/02 5:39:53 AM Pacific Standard Time, nuckolls(at)kscable.com writes: << What kind of multi-meter are you using? Some of the lower cost, analog devices don't have a good low ohms capability. For example, I have an old "pocket" mulitmeter that reads 1000 ohms at midscale on the lowest resistance setting. >> Thanks Bob. And I have an old Micronta (Radio Shack) multimeter that "should" read 10 ohms midscale on the lowest setting. When I checked the resistance of a diode in the forward direction I read about 4 ohms. Does that sound about right? Harry Crosby Pleasanton, California RV-6, wiring ________________________________________________________________________________
Date: Mar 11, 2002
From: "Jerry Morris" <Jerry.Morris(at)nsc.com>
Subject: help with a welen strobe????
Can anyone tell me were to find a schematic for a Whelen comet flash strobe. This unit flashes once and stops working; What was found after opening is a powered component. It looks like it might have been a ressistor, but not sure..... its wire does not stick up as high as a diode close by, so i need help to get this unit back into the air. I can't even find a bad unit to buy to see what this part was. If anyone can help please let me know. thanks jerrym(at)nsc.com ________________________________________________________________________________
Date: Mar 11, 2002
From: Michel Therrien <mtherr(at)yahoo.com>
Subject: Re: help with a welen strobe????
What powersupply is that (what model exactly)? Can you take a picture of the component's location? Perhaps I could open mine and try to identify it for you. Michel --- Jerry Morris wrote: > Morris" > > Can anyone tell me were to find a schematic for a > Whelen comet flash strobe. > > This unit flashes once and stops working; What was > found after opening is a > powered > > component. It looks like it might have been a > ressistor, but not sure..... > its wire > > does not stick up as high as a diode close by, so i > need help to get this > unit back into the air. > > I can't even find a bad unit to buy to see what this > part was. > > If anyone can help please let me know. > > thanks > jerrym(at)nsc.com > > > > Forum - > Contributions of > any other form > > latest messages. > other List members. > > aeroelectric-list(at)matronics.com > http://www.matronics.com/subscription > http://www.matronics.com/photoshare > http://www.matronics.com/browselist/aeroelectric-list > http://www.matronics.com/search > http://www.matronics.com/archives > http://www.matronics.com/emaillists > > > > > ===== ---------------------------- Michel Therrien CH601-HD http://pages.infinit.net/mthobby http://mthobby.pcperfect.com/ch601 ________________________________________________________________________________
Date: Mar 12, 2002
From: Graham Singleton <grasingleton(at)avnet.co.uk>
Subject: Re: PVC insulation - EIS 4000
>I'm sorry but PVC just isn't acceptable in aircraft period. The amount of >money you might save is insignificant when you consider the PVC will crack >and possible shortout. This will overheat it. Not only that, with ageing it will release hydrogen chloride vapour which causes corrosion. Graham ________________________________________________________________________________
From: "Richard D. Fogerson" <rickf(at)velocitus.net>
Subject: Contactors, Current Limiters on Z22
Date: Mar 11, 2002
Hi Bob, Just a few quick questions: 1) Do all the Z diagrams use S704-1 for starter contactors and S701-1 for Battery Contactors? 2) Z-22 (Permanent Magnet "run-on") says "size B-lead ANL limiter to Alternator and AWG to match". For a B&C 40 amp would that be ANL 60 and 6 AWG? ________________________________________________________________________________
Date: Mar 12, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Contactors, Current Limiters on Z22
> > >Hi Bob, >Just a few quick questions: > >1) Do all the Z diagrams use S704-1 for starter contactors and S701-1 >for Battery Contactors? Yes. However, we call out those numbers as minimum-effort acquisitions of two of many parts suited to the task. >2) Z-22 (Permanent Magnet "run-on") says "size B-lead ANL limiter to >Alternator and AWG to match". For a B&C 40 amp would that be ANL 60 and >6 AWG? We needed to upsize earlier JJS/JJN series fuses with respect to their alternators because of very fast response of the fuses. ANL limiters are much more robust as described in . . . http://209.134.106.21/articles/anl/anlvsjjs.html . . . and are picked with ratings closer to the output of alternator. Therefore a 40A alternator gets an ANL40, the 60A alternator gets an ANL60 Bob . . . ________________________________________________________________________________
Date: Mar 12, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Contactor confusion
> >In a message dated 3/11/02 5:39:53 AM Pacific Standard Time, >nuckolls(at)kscable.com writes: > ><< What kind of multi-meter are you using? Some of the lower cost, analog >devices don't have a good low ohms capability. For example, I have an old >"pocket" mulitmeter that reads 1000 ohms at midscale on the lowest resistance >setting. >> > > >Thanks Bob. And I have an old Micronta (Radio Shack) multimeter that >"should" read 10 ohms midscale on the lowest setting. When I checked the >resistance of a diode in the forward direction I read about 4 ohms. Does >that sound about right? When you put an ohmmeter across a diode, keep in mind that you're really measuring a voltage drop. The true resistance of a diode is very low . . . generally on the order of tens of milliohms. The "resistance" reading for a diode will vary somewhat from meter to meter but the reading cited in your case is not unreasonable. I'm surprised that this instrument doesn't seem to measure the resistance of the contactor coils. Bob . . . ________________________________________________________________________________
Date: Mar 12, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Alternator Problem
> >Hi All, > >I just had a problem with my alternator and discovered the bracket holding >it on was broken. In disassembling it I notice what I thought was a ground >wire to the shielding was broken and not making contact. > >After reassembling I noticed the shielding(on the ground wire) was not >grounded on the other side so I left it off. Now I noticed when I first was >having a problem that my alternator was discharging. Well after replacing >the bracket and reattaching the wires(hopefully correctly), I am still >discharging. Before I remove the alternator and take it to be tested, do you >think I could have replaced the two small wires incorrectly on the >alternator? Could what I thought was a ground wire to the shielding been >something else? Improper connection of shields should make no difference with respect to proper alternator operation. In fact, the notion that alternator installations benefit from any form of shielding is a myth perpetrated by Cessna's ADF installations of the 1960's and perpetuated into tens of thousands of other airplance since. You need to troubleshoot your alternator installation per Note 8 of http://209.134.106.21/articles/Rev10/z10.pdf Bob . . . ________________________________________________________________________________
Date: Mar 12, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Polyfuse
>reate a problem for the voltage regulator? > > I've not taken the time to run any tests using the crowbar > OV protection system with Polyswitches . . . The fault current > that flows in the milliseconds after a OV condition is detected > can be as high as 300 amps. This causes the 5A breaker to open > right smartly. It is possible that the Polyswitch time delays > are sufficiently longer under these conditions to put etched > circuit board traces inside the LR3 regulator at risk.>> > >Maybe I can help. The "Polyfuse" is an NTC device designed to have a very >steep temperature curve. It is not a fuse as such, but is more correctly >called a "current limiter." I understand how they work. What I've not investigated are the time constants for their operation. There's an I(squared)*T constant for fuses and breakers that describe dynamic behavior of a protective device. What I cannot assert now is whether or not the crowbar OV system as it presently exists in our products will live and work happily with the Polyswitch anyone chooses to use in their off-the-shelf wiring product. By-in-large, I can find no redeeming pre-wired switch panels with or without Polyswitches . . . careful analysis of cost and time to install shows that these products do not live up to their advertising hype. Many of my builders are wiring their complete airplane, wire, contactors, switches, terminals, fuseblocks, etc for less than the cost of a pre-wired product and in the same amount of time. See: http://209.134.106.21/articles/xpbusthd.html http://209.134.106.21/articles/expbusad.html anyone interested in more data on Polyswitches can check . . . http://www.circuitprotection.com/litbrochures/shortformcatalog.pdf Bob . . . ________________________________________________________________________________
From: jacklockamy(at)att.net
Subject: Cessna Split Master Switch
Date: Mar 12, 2002
To the list; New subscriber...first post. Question: Can a Cessna Split Master Switch (S1994) handle up to 20 AMPS? I would like to run a wire from my voltage regulator through the switch so I could isolate my stator from the entire system should it fail. TIA, -- Jack Lockamy Sonex #300 Camarillo, CA. www.jacklockamy.com ________________________________________________________________________________
Date: Mar 12, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: PVC insulation - EIS 4000
> >I've just started the installation of a Grand Rapids EIS 4000 engine >monitor in my RV-8. I had assumed that all the wiring would have >aircraft quality tefzel installation, but I just learned that the >harness going into the unit have PVC insulation. > >So now I have some thinking to do. First I must decide how much of >the wiring I will replace, and then I must convince the Canadian >inspector of the correctness of my plan. I'll contact the inspector >as soon as I have done my thinking and have a convincing story. If >he is going to insist on a major rewiring I would rather know now >before I get too deep into this. > >I need to acquire some knowledge on PVC insulation. I assume there >are three potential issues: > >1. Noxious fumes if the insulation is overheated (yes, I agree that >no wires in a properly designed and installed electrical system >should ever overheat. However, we still read about the occasional >electrical smoke or fire incident, even on type certificated >aircraft); > >2. Abrasion resistance not as good as tefzel insulation; and > >3. Shorter life than tefzel insulation. > >Tackling these issues in order: > >1. I assume that PVC insulation on some wires is OK, as not all wires >are at risk of getting hot. I could use PVC insulation as long as >the wires in question are routed well clear of the exhaust system, >handle low voltage/low power signals (i.e. CHT and EGT extension >wires) and are not in the same bundle as wires with power sources. >Are these criteria reasonable? > >2. Assuming the wires in question are well secured and cannot chafe >against anything, are there any other abrasion issues to worry about? > >3. How does the life of PVC insulation compare to tefzel? What >failure modes should I expect as the wire ages? What warning signs >should I look for? These questions generally produce lots of response . . . Had we been building airplanes in 1890, wires would be insulated with tar and hemp. Then cotton covered rubber could have come along and everyone with new wire to sell would pour forth with all the evils of the past and extoll virtues of the present. In 1960 we were wiring airplanes with nylon jacketed PVC . . . the best we knew how to do then. Pretty soon, here comes Teflon . . MUCH better in many respects but not without it's own evils . . . very toxic out-gassing when overheated. Then comes Tefzel . . . lower temps than Teflon, more rugged and not quite so toxic. Then comes Kynar . . . I had to beat vendors off with clubs while working the GP-180 project at Learjet in 1983 . . . my airplane was going to be "hundreds of pounds overweight" if I didn't champion the new latest and greatest. Looking back, many of the airplanes I rent are wired with nylon over PVC wires. They're 30+ years old and the wires are still flexible and insulations are intact. Wires under the cowl are in pretty good shape too . . . because they've probably been replaced a number of times over the years . . . Further, we've read where the very thin, very tough Kynar insulation has a degradation mode that may have precipitated the cabin fire in an airplane over the North Atlantic a few years back. Here are some brief tech data sheets on PVC and Tefzel. http://www.endura.com/material1.htm#7 http://www.endura.com/material1.htm#37 Bottom line is that I wouldn't loose any sleep over PVC instrumentation wires in the cockpit. Probability of future difficulties with the wire any time in the next 30 years is remote. Further, the outcome of some problem being markedly influenced by the the fact that the wire is covered in Tefzel as opposed to PVC is even more remote. PVC under the cowl is easy to observe and apply maintenance as required. Probability of an uncomfortable situation arising out of an instrumentation loss is remote. So, your real problem is how to deal with a bureaucrat primed to pay homage to the latest approved mantra. You're on your own there my friend. My advice has to be based on an understanding of physics and observations of history. Bureaucrats are not renowned for their ability to exercise those skills. None the less, I would lean on EIS with great enthusiasm to upgrade their product. It's not an expensive thing to do . . . they've just been lazy. Bob . . . ________________________________________________________________________________
Date: Mar 12, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Cessna Split Master Switch
> >To the list; > >New subscriber...first post. > >Question: Can a Cessna Split Master Switch >(S1994) handle up to 20 AMPS? I would like to run a >wire from my voltage regulator through the switch so >I could isolate my stator from the entire system >should it fail. Better to wire it per Figure Z-16 of http://209.134.106.21/articles/Rev10/z10.pdf The infamous split-rocker has the same guts in it as switches offered at: http://www.aeroelectric.com/Catalog/switch/switch.html#switch Suggest you review additional links on this page about features of these switches. By-in-large, the switches shouldn't be used for loads exceeding 10A, 100W landing lights and pitot heaters are only 8A . . . Bob . . . ________________________________________________________________________________
Date: Mar 12, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Thermocouple connections
> ><D-sub pins, but just crimping them to the push-ons on the other end is OK. It >would not be possible to solder to the push ons that VMS provided or the >ones >that I used because of the insulation. Also I believe that the push-ons on >the end of the thermocouple lead wires were soldered on by the factory that >produced the thermocouples and the leads. (I can't easily check because the >leads are now all covered up in wire looms.)>> Don't know where "solder" was even mentioned much less recommended. You can't soft-solder thermocouple wires. You can silver-solder them but this is useful only for joining wires or making a thermocouple out of bulk wire. See: http://209.134.106.21/articles/excerpt.pdf I prefer d-sub connectors for thermocouples using the MACHINED crimp on pins which grab the wire in a four-quadrant munch. These pins are always gold plated. >I think there is too much worrying going on about TC connections. In the >old days we used meters for temperature read-outs that were sensitive to >circuit resistance, but these days the interface is a very high impedance >electronic one. If the pair of connections is at the same temperature the >error in reading should be very small, in my experience. In other words, if >you connect the positive TC wire to a copper wire at the same location that >the negative one is connected it will cancel out the TC effect of the >connection. Not true. The location of a copper to thermocouple junction defines the system's "cold" junction. If one KNOWS what the temperature of that junction IS and allows for in in system calibration, it's entirely satisfactory. See view B of figure 14-10 in the article cited above. The switching technique I described in the earlier post puts a pair of opposing "cold" junctions in series to accomplish the cancellation you've alluded to above . . . but they have to come in opposing pairs. > But if the positive one is connected, say, in the engine >compartment and the negative goes into the cockpit before it changes to >copper you can expect an error in reading roughly in the amount of the >difference in temperature. I can't see where on flux will have an effect >compared to another - or even crimped compared to soldered. One can only "worry" about thermocouples if one doesn't understand thermocouples. It's true that modern thermocouple instruments are LESS sensitive to loop resistance of the thermocouple but there are things that introduce significant errors that are EASY to avoid. Got a box on my workbench right now that's going to go back into a Beechjet for some temperature studies on a pitot-heat deicing system. Two sets of d-sub pins in each thermocouple loop. Here's another example of how copper-clad can be used to fabricate custom enclosures: http://209.134.106.21/temp/MVC-036X.JPG Here's a view of the serially interrogated data acquisition modules . . . these cost about $50 each off the internet: http://209.134.106.21/temp/MVC-037X.JPG Here's how the electronics are mounted on a hefty aluminum plate that also mounts a couple of heaters to keep the interior of the box about 10 degrees C. http://209.134.106.21/temp/MVC-039X.JPG Here are the thermocouple data conversion chips that take care of cold-junction compensation and give me a nice 10 mV/Degree C output signal. Note connector in foreground terminates 12 pairs of thermocouple wire that extends TC data right up to the chips: http://209.134.106.21/temp/MVC-041X.JPG You guys with laptops can use this relatively simple data acquisition technique to go find out whats REALLY happening under the cowl. Bob . . . ________________________________________________________________________________
From: jacklockamy(at)att.net
Subject: Re: Cessna Split Master Switch
Date: Mar 12, 2002
Thanks for the reply Bob. I will review the .pdf document you referenced/linked. Would you mind taking a look at my DRAFT electrical diagram to see if I have any potential problem areas? My diagram can be found on the lower left side of my homepage (see www.jacklockamy.com). It is a .pdf file also. I have started running some of the wire and would like a second or third opinion if anyone cares to comment or provide suggestions. In places where I changed from 14 AWG to 8 AWG on the same run....I changed it all to 8 AWG (haven't updated drawing yet.) TIA, -- Jack Lockamy Camarillo, CA. www.jacklockamy.com > > > > > >To the list; > > > >New subscriber...first post. > > > >Question: Can a Cessna Split Master Switch > >(S1994) handle up to 20 AMPS? I would like to run a > >wire from my voltage regulator through the switch so > >I could isolate my stator from the entire system > >should it fail. > > Better to wire it per Figure Z-16 of > http://209.134.106.21/articles/Rev10/z10.pdf > > The infamous split-rocker has the same guts > in it as switches offered at: > > http://www.aeroelectric.com/Catalog/switch/switch.html#switch > > Suggest you review additional links on this > page about features of these switches. > > By-in-large, the switches shouldn't be used > for loads exceeding 10A, 100W landing lights > and pitot heaters are only 8A . . . > > Bob . . . > > > > > > ________________________________________________________________________________
Date: Mar 12, 2002
Subject: Re: Cessna Split Master Switch
From: <racker(at)rmci.net>
> > By-in-large, the switches shouldn't be used > for loads exceeding 10A, 100W landing lights > and pitot heaters are only 8A . . . Bob, I was just about to hookup my two 55W landing lights to a relay coming off off a 2-10 switch. Am I safe to assume from the above statement, that I could wire the 9.2A (@12v) load directly to a switch and be okay (likewise for my 7.4A nav and 8A pitot tube loads)? I'd like to reduce parts count as much as possible without affecting safety. Thanks, Rob (RV-6). ________________________________________________________________________________
Date: Mar 12, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: Thermocouple connections - PostScript
Here are the thermocouple data conversion chips that take care of cold-junction compensation and give me a nice 10 mV/Degree C output signal. Note connector in foreground terminates 12 pairs of thermocouple wire that extends TC data right up to the chips Forgot to mention . . . look closely at how the thermocouple wires drop onto the etched circuit board adjacent to the integrated circuits in the foreground . . . I crimped male d-sub pins onto the wires and then soldered the PIN to the board. Except for silver-soldered thermocouples on the far end of each circuit, all joining of thermocouple wires are d-sub pin crimps . . . When I calibrated this system against an ice bath, individual T/C chips had errors of as much as 3 degrees C which was were washed out in correction values entered into the data acquisition program. The thermcouple wiring errors were less than 0.5 degrees C in spite of the fact that each circuit had 18 joints between the thermocouple and the instrumentation chip. Here's a link to that photo again: http://209.134.106.21/temp/MVC-041X.JPG Bob . . . -------------------------- TEMPORARY WEBSITE ADDRESS: http://209.134.106.21 -------------------------- ________________________________________________________________________________
Date: Mar 12, 2002
From: Kevin Horton <khorton(at)cyberus.ca>
Subject: Re: PVC insulation - EIS 4000
> > >> >>I've just started the installation of a Grand Rapids EIS 4000 engine >>monitor in my RV-8. I had assumed that all the wiring would have >>aircraft quality tefzel installation, but I just learned that the >>harness going into the unit have PVC insulation. >> >>So now I have some thinking to do. First I must decide how much of >>the wiring I will replace, and then I must convince the Canadian >>inspector of the correctness of my plan. I'll contact the inspector >>as soon as I have done my thinking and have a convincing story. If >>he is going to insist on a major rewiring I would rather know now >>before I get too deep into this. >> >>I need to acquire some knowledge on PVC insulation. I assume there >>are three potential issues: >> >>1. Noxious fumes if the insulation is overheated (yes, I agree that >>no wires in a properly designed and installed electrical system >>should ever overheat. However, we still read about the occasional >>electrical smoke or fire incident, even on type certificated >>aircraft); >> >>2. Abrasion resistance not as good as tefzel insulation; and >> >>3. Shorter life than tefzel insulation. >> >>Tackling these issues in order: >> >>1. I assume that PVC insulation on some wires is OK, as not all wires >>are at risk of getting hot. I could use PVC insulation as long as >>the wires in question are routed well clear of the exhaust system, >>handle low voltage/low power signals (i.e. CHT and EGT extension >>wires) and are not in the same bundle as wires with power sources. >>Are these criteria reasonable? >> >>2. Assuming the wires in question are well secured and cannot chafe >>against anything, are there any other abrasion issues to worry about? >> >>3. How does the life of PVC insulation compare to tefzel? What >>failure modes should I expect as the wire ages? What warning signs >>should I look for? > > These questions generally produce lots of response . . . > > Had we been building airplanes in 1890, wires would be > insulated with tar and hemp. Then cotton covered rubber > could have come along and everyone with new wire to sell > would pour forth with all the evils of the past and > extoll virtues of the present. > > In 1960 we were wiring airplanes with nylon jacketed > PVC . . . the best we knew how to do then. Pretty soon, > here comes Teflon . . MUCH better in many respects but > not without it's own evils . . . very toxic out-gassing > when overheated. Then comes Tefzel . . . lower temps > than Teflon, more rugged and not quite so toxic. Then > comes Kynar . . . I had to beat vendors off with clubs > while working the GP-180 project at Learjet in 1983 . . . > my airplane was going to be "hundreds of pounds overweight" > if I didn't champion the new latest and greatest. > > Looking back, many of the airplanes I rent are wired > with nylon over PVC wires. They're 30+ years old > and the wires are still flexible and insulations are > intact. Wires under the cowl are in pretty good shape > too . . . because they've probably been replaced a number > of times over the years . . . > > Further, we've read where the very thin, very tough > Kynar insulation has a degradation mode that may have > precipitated the cabin fire in an airplane over the > North Atlantic a few years back. > > Here are some brief tech data sheets on PVC > and Tefzel. > > http://www.endura.com/material1.htm#7 > http://www.endura.com/material1.htm#37 > > Bottom line is that I wouldn't loose any sleep over > PVC instrumentation wires in the cockpit. Probability > of future difficulties with the wire any time in the > next 30 years is remote. Further, the outcome of some > problem being markedly influenced by the the fact that > the wire is covered in Tefzel as opposed to PVC > is even more remote. > > PVC under the cowl is easy to observe and apply > maintenance as required. Probability of an > uncomfortable situation arising out of an > instrumentation loss is remote. > > So, your real problem is how to deal with a > bureaucrat primed to pay homage to the latest > approved mantra. You're on your own there my > friend. My advice has to be based on an understanding > of physics and observations of history. Bureaucrats > are not renowned for their ability to exercise > those skills. > > None the less, I would lean on EIS with great > enthusiasm to upgrade their product. It's > not an expensive thing to do . . . they've > just been lazy. > > Bob . . . > Bob, Thanks for the info and advice. I've decided I will replace the power input wire, and the one that provides 5v output to one of my senders. I'm comfortable leaving the other PVC stuff alone. I'll contact the folks who run the organization that does the official inspections up here to see what their policy is. Then I'll contact the local inspector. If I can't convince them to allow PVC on instrumentation wires, I'll redo the rest of the harnesses. I contacted Grand Rapids, and Greg offered to redo the harness with the wire of my choice if I want. I may still go down that road, which would leave PVC on only the thermocouple wires. I haven't managed to find a supplier of tefzel insulated thermocouple wires yet. Take care, -- Kevin Horton RV-8 (installing engine & electrics) Ottawa, Canada http://eccentrix.com/misc/rv8/rv8.html ________________________________________________________________________________
Date: Mar 12, 2002
From: "Robert L. Nuckolls, III" <nuckolls(at)kscable.com>
Subject: Re: PVC insulation - EIS 4000
> > > > None the less, I would lean on EIS with great > > enthusiasm to upgrade their product. It's > > not an expensive thing to do . . . they've > > just been lazy. > > > > Bob . . . > > > >Bob, > >Thanks for the info and advice. > >I've decided I will replace the power input wire, and the one that >provides 5v output to one of my senders. I'm comfortable leaving the >other PVC stuff alone. > >I'll contact the folks who run the organization that does the >official inspections up here to see what their policy is. Then I'll >contact the local inspector. If I can't convince them to allow PVC >on instrumentation wires, I'll redo the rest of the harnesses. > >I contacted Grand Rapids, and Greg offered to redo the harness with >the wire of my choice if I want. I may still go down that road, >which would leave PVC on only the thermocouple wires. I haven't >managed to find a supplier of tefzel insulated thermocouple wires yet. Okay . . . at least GR is now aware of the problems that some of their customers are experiencing. I hope they move to fix the product line and not just your harness (should that become necessary). Goto http://www.omega.com/toc_asp/subsectionSC.asp?subsection=H06&book=Temperature down the page you will find type J and type K duplex thermocouple wire listed. Your looking for TT-K-## or TT-J-## where ## is the wire gage. I use a lot of TT-K-20 and TT-J-20 in solid wire. It's my favorite for use with the 20AWG d-sub connectors. You can build a part number consisting of "TT" for teflon over teflon, "J" or "K" for the kind of thermocouple and then a length value. For example, 25' of TT-K-20 is $31 plus shipping. You can select a part number, add it to a shopping cart and buy the stuff right on line. OMEGA is a good company to do business with. Bob . . . ________________________________________________________________________________
From: "Werner Schneider" <WernerSchneider(at)compuserve.com>
Subject: Combining Insight gem and Rocky Mountains engine Monitor
Date: Mar 13, 2002
Hello Bob, you're very helpfull comments in this list are very well appreciated. I hope you can give me also some advice. I plan to use a RKYM engine monitor, now what I dont like is, that I can monitor one pair of temp only. I got a Insight Gem603 monitor (which a friend just fixed). My idea is now, to use both instruments together. -I have no sensors yet, can I use the sensors from RKYM also for the Insight? -is there a electronic available, which I could integrate between the Gem and RYM which would change the pair of sensor every say 30 sec? This would allow a logging of engine data on all cylinders. -Is there any problem to run two instruments with one set of sensors? -Any opinion about this approach and RKYM? Many thanks for your help and your book is worth any cent! Werner (Glastar final assembly) ________________________________________________________________________________
From: BAKEROCB(at)aol.com
Date: Mar 13, 2002
Subject: soldering thermocouple wire
In a message dated 03/13/2002 2:52:39 AM Eastern Standard Time, nuckolls(at)kscable.com writes: << Don't know where "solder" was even mentioned much less recommended. You can't soft-solder thermocouple wires. You can silver-solder them but this is useful only for joining wires or making a thermocouple out of bulk wire.......skip..... >> 3/13/2002 Hello Again Bob, Soldering thermocouple wires was brought up in my responding posting to Kevin Horton (repeated below) wherein I quoted instructions from Vision Microsystems about soldering type J and K wires to stamped pins for their engine instrumentation system. You are now confirming that even this soldering has no value or effect? Also it would appear that push-on connectors when properly crimped and polarized would function the same as the connectors shown in Figure 14-13 of The Aeroelectric Connection. Thanks. 'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - ?/?/? Subj: fast ons for thermocouple wiring Date: 03/10/2002 In a message dated 03/10/2002 2:53:27 AM Eastern Standard Time, khorton(at)cyberus.ca writes: << ....skip..... Hmm. I getting very confused. My original question was in regard to

February 27, 2002 - March 13, 2002

AeroElectric-Archive.digest.vol-aq