---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 02/08/14: 19 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:09 AM - Re: Analyze This (Peter Pengilly) 2. 04:14 AM - Re: Essential Bus question (Bill Watson) 3. 05:22 AM - Re: Mac's theory defies the laws a physics (Robert L. Nuckolls, III) 4. 05:48 AM - Re: Fuselage as ground conductor (Robert L. Nuckolls, III) 5. 07:31 AM - Re: Mac's theory defies the laws a physics (Vern Little) 6. 07:55 AM - Re: Mac's theory defies the laws a physics (Jared Yates) 7. 08:33 AM - Timer circuit for led array (Bob Verwey) 8. 09:03 AM - Re: Timer circuit for led array (Robert L. Nuckolls, III) 9. 09:06 AM - Re: Essential Bus question (Robert L. Nuckolls, III) 10. 09:30 AM - Re: Connectors and factories (D L Josephson) 11. 09:31 AM - Re: Timer circuit for led array (Bob Verwey) 12. 10:52 AM - Re: Analyze This (Jeff Luckey) 13. 11:09 AM - Re: Fuselage as ground conductor (BobsV35B@aol.com) 14. 03:25 PM - Re: Essential Bus question (Bill Watson) 15. 03:28 PM - Re: Mac's theory defies the laws a physics (Robert L. Nuckolls, III) 16. 04:52 PM - Re: Essential Bus question (Kelly McMullen) 17. 06:00 PM - Re: Essential Bus question (Tim Andres) 18. 08:35 PM - Timer circuit for led array (Bob Verwey) 19. 08:35 PM - Re: Mac's theory defies the laws a physics (Richard Girard) ________________________________ Message 1 _____________________________________ Time: 01:09:58 AM PST US From: Peter Pengilly Subject: Re: AeroElectric-List: Analyze This Jeff, I would like a little explanation of the basic operation. I'm assuming both master switches on all the time, both batteries are the same, throw one battery away each year. If alternator fails no simple load shedding is available, pilot must select items individually (or have a check-list of what to switch off). You're now wasting 2 amps (1 or each battery contactor). Think about the information you want the 2 shunts to provide, will the do that, is there a better (simpler) way? As you already have the power indicators, I would put the shunt in the alternator to bus feed. Agree with comment about fusing (or current limiting) feed to batt B. I thought a current limiter was better placed in the alternator output? I'm unsure what the 'K-...' means 2 batteries will provide way more than 45 minutes operation on battery power, even with a very full panel and no load shedding. Therefore system grossly exceeds design goal resulting in more cost/weight than required. Where does 45 minutes come from? FAR-23 requires 30 minutes, alternatively assume half or full fuel endurance. No simple load shedding appears available - meets goal 2 (but perhaps goal 1 & 2 are actually, survive any failure for 45 minutes with no pilot interaction) System seems more complex/costly than a 2 bus system would be. Seems that goals 1 & 2 are weighted much more highly than the others? Its your airplane, build the system that meets your needs. Regards, Peter On 02/02/2014 23:38, Jeff Luckey wrote: > Listers, > > Attached find a schematic (some people call them ladder diagrams) of a > design for the electrical system for my RV-7A. Below is a list of > design goals, pros and cons. Please take a look and provide > engineering feedback. > > TIA > > > Electrical Systems Design Goals: > 1. fault tolerant - able to tolerate failure of any single component > and fly for 45 min. > 2. easy to operate > 3. no avionics brown-out on engine start > 4. easy to repair > 5. comprised of standard, readily-available components > 6. cost effective > > > Pros: > 1. simplified operation - only 2 master switches > 2. simplified design - single buss > 3. no brown-out on engine start > 4. automatic fail-over - no pilot interaction required; avionics won't > reset > In the event a battery system suffers a failure, either an open > circuit or a ground fault, the faulty > system simply stops providing power to the buss and the remaining good > system continues to > provide electricity without interruption. > > Cons: > 1. buss-isolation power diodes may require heat sinks > 2. some energy wasted as heat thru power diodes > > ________________________________ Message 2 _____________________________________ Time: 04:14:32 AM PST US From: Bill Watson Subject: Re: AeroElectric-List: Essential Bus question I don't know if the TCW product was available when I was panel building in the 2008-2010 timeframe but I never saw or heard any recommendation from GRT about the TCW backup battery. They certainly were having "brown out issues" with the HXs because we found that they don't like to have their boot processes interrupted by loss of power incidents, which in my case became every single start in low temps. They should have bought TCW's unit and made it a recommended option but I think they were busy working on the newer EFISs. In fact, I recently added TCW's IPS (Power stabilizer) to my (3) units and the G430 and that did the trick without adding any additional batteries to maintain. Kelly, I apologize for jumping on your post and accept your statement that you are not a fan of dual bus, dual alternator, dual battery systems (though you don't exactly explain why). The simplicity and symmetry of the Z-14 is what attracted me in the first place. I still have trouble wrapping my mind around the essential bus and how I would apply it to my 'kitchen sink' panel without having to add switches so I could perform triage on my triad of GRT EFISs. Or adding a little Dynon or something as a backup. Just what I needed was another brand of EFIS to learn to operate. To me, those approaches add operational complexity and additional failure points but I could be wrong. But what got me is that you didn't express a distaste for the Z-14, which I accept. Instead your post inadvertently dismissed the very way I operate my aircraft by saying: Virtually all glass have their own light weight backup batteries so do not have startup brown out issues unless no backup battery is installed. (not GRT HXs) I see very little value in being able to turn on GPS prior to start. (I need the G430 prior to start, perhaps independent of the GPS. I need at least one EFIS to see my engine instruments. Having the Navworx ADSB up for weather is nice too so I can time my departure around those Gulf Coast thunder bumpers, but the G430 is the problem) While one needs engine instrumentation prior to and during start, one does not need avionics on. (I do unless I want to switch out 1 or all of my 3 EFISs - talk about a additional points of failure on a critical instrument) Of course newer avionics that allow faster input of flight plans than the 430 help, if that is the reason for turning on 430 before start. (It is but perhaps I should upgrade or at least get Siri (!!??) for my G430) I guess you can see my feathers remain ruffled. Sorry for continuing the 'argument' but as you said we make our own choices and can argue with anyone who does differently. Honestly Mr Nuckolls is the guy who puts my nose out of joint with the "kitchen sink" stuff. Just as Bob and this list has enabled me to design and build my dream traveling machine, I feel the need to defend all that has been enabled. Bob, I love you man! I value your advice, counsel and guidance above all others. This list and the people on it, especially folks like Kelly, are to die for. Just please stop calling my panel a "kitchen sink". I promise I'll upgrade it, pare it down and streamline it with some excess $$$$ the next time I see the opportunity to do it. But I'll probably keep the Z-14 so when someone runs across the ramp to tell me I left my master on, I can shrug my shoulders and say "no problem, I've got a Z-14 and enough juice to run it for another 20 minutes and still start it up and get out of here". Not a requirement but I enjoy it nonetheless. Thanks for letting me vent... feel free to return the favor. And thanks for taking the time to respond. Bill "I REALLY like my panel" Watson On 2/7/2014 9:32 PM, Kelly McMullen wrote: > > > Bill, > I don't know what was available when you designed your system. Grand > Rapids recommends http://www.tcwtech.com/IBBS.htm for backup battery, > and TCW says it is also suitable for backup of G430. > Dynon offers its own backup battery managed by the EFIS software to > takeover at 12.3 volts. > Garmin 650 and 750 know airways, unlike their older brethern. > I get the need for airways and not wanting to re-enter flight plan > after start, or wait to after start to do it with the price of gas. > There is also a voice activated add on for the 430 for data entry that > Knows airways. > What I "get" is the desire to keep electrical system as simple as > possible as the primary means to reduce failure points. If reboot > becomes a problem with my GTN 650, I will add a TCW unit. I'm just not > a fan of dual bus, dual alternator, dual battery systems, but we are > OBAM so we can make our own choices and argue with anyone who chooses > differently. ;-) > Kelly > On 2/7/2014 3:30 PM, Bill Watson wrote: >> >> >> Sorry about adding to this rather old discussion but I've been away >> for awhile. >> >> I finished my RV10 in 2011 which means that I designed my electrical >> system and panel around 2008 for a 2009-2010 build. >> >> I have 3 GRT HX EFISs - 2 aimed at the pilot, 1 at the passenger. >> They supply synthetic vision, moving map, weather, traffic and a >> complete suite of engine stats. No light weight backup batteries >> can be configured at the factory with these systems. These screens >> have no integral on/off switch. I chose not to add any switches or >> operable CBs. They come on with the master and will usually reboot >> when my IO540 cold starts with a single, fresh PC 680 battery. >> >> The GPS WAAS smarts for this system are supplied by a G430W. >> >> I am a serious traveler with this machine and practically all flight >> are on IFR plans. My normal routine for all flights is to file my >> plan using Foreflight on an iPad. Whenever at an airport with >> clearance delivery, or when departing into IMC conditions, I obtain >> my clearance on the ground, before engine start, and enter it into my >> iPad and then into my G430. Many times in congested areas, this >> entry is followed by no small amount of study. As my aging mind >> continues to fog over, I'm finding that the study time grows. >> >> Here's the challenge on G430 based panels; it loses any entered >> flight plan when powered off. An engine start that reboots my GRTs, >> reboots my G430. >> >> An acute challenge on 430 based panels when used for flights around >> the Wash DC area or for flights along Florida's Atlantic coast is >> that the G430 does not know what a Victor airway is. These are >> flights I make regularly and clearances in these areas typically >> still include Victor airways. So in the routine described above, >> entry into the iPad generates the necessary waypoints to any Victor >> airways. Accurate entry of these waypoints into the G430 is >> important and there's no way I want to redo the work. >> >> As Bob would put it, this is the 'kitchen sink' I choose to fly >> with. I think it's fantastic and works very very well for me. It's >> now a well grooved swing. The inability of some (e.g. Bob, not >> necessarily you Kelly but I did choose to respond to your post) to >> 'get' this requirement for this pilot, seems to me is just an >> inability to see past old school experience or perhaps your current >> pleasure flying routines. >> >> I have a Z-14 with 2 batts, 2 alts, and 2 buses and I REALLY like >> it. I bring up the 'kitchen sink' on one battery, get my clearances, >> enter them into my systems, study my departure plan when doing >> complicated airspace or low IMC departures and then bring up the 2nd >> battery bus, cross link them and start my engine. Everything stays >> up. Before takeoff I've learned, per Bob, to de-link the buses and >> off I go. >> >> Per Bob, I've eliminated any semblance of an avionics bus, extra >> switches or CBs. After a few operational adjustments and refinements >> (Thanks Bob!), the 'overkill' of a Z-14 has given me exactly what I >> think I need. >> >> I need my avionics on before start and I have a big kitchen sink that >> takes care of the dishes just like I want them done. So can we >> please stop dismissing this approach to equipping and traveling in >> our very fine OBAM aircraft within the user fee free ATC system we >> have? Some of us do it every day because that's the way we choose to >> roll. >> >> PS: I've been out of the loop island hopping the Bahamas. Recommend >> it highly. What an adjustment flying VFR from place to place! >> However, I still used the same procedures because that's what >> standard procedures are for. >> >> Bill "It's pretty darn good in the Bahamas" Watson >> N215TG >> On 2/2/2014 7:14 PM, Kelly McMullen wrote: >>> >>> >>> Virtually all glass have their own light weight backup batteries so >>> do not have startup brown out issues unless no backup battery is >>> installed. >>> I see very little value in being able to turn on GPS prior to start. >>> While one needs engine instrumentation prior to and during start, >>> one does not need avionics on. >>> Of course newer avionics that allow faster input of flight plans >>> than the 430 help, if that is the reason for turning on 430 before >>> start. >>> >> >> >> >> >> > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > > ________________________________ Message 3 _____________________________________ Time: 05:22:34 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Mac's theory defies the laws a physics At 05:44 PM 2/7/2014, you wrote: >Reminds me of an article that was in the Oct. 2013 (page 12) Sport >Aviation. Doesn't anyone review these articles? > > >Raymond Julian >Kettle River, MN. Yup, we discussed that article here on the List ----------------------------------------------------- Subject: Re: AeroElectric-List: Mac's theory defies the laws a physics At 04:55 PM 2/7/2014, you wrote: > >Gents, > >I like Mac most of the time, but here I believe he's all wet. Agreed. The physics of the 'dreaded downwind turn' are firmly rooted in the anecdotal but sad observation that so many accidents have occurred while trying to accomplish this maneuver. But if one studies the motion of a winged body during a maneuver intended to reverse direction quickly and return to the airport, acceleration of the airplane's mass in a new direction is a smooth, continuous activity promoted by the horizontal component of lift that MUST be present in the coordinated turn. We explored this line of reasoning last October during which I posted this response . . . Post Posted: Mon Oct 07, 2013 4:15 pm Post subject: The dreaded downwind turn . . . Reply with quote ---------- At 10:48 AM 10/7/2013, I wrote: Quote: When he started talking about the the wind accelerating to aircraft during the turn, he lost me. As soon as he says "a lighter aircraft will accelerate faster than a heavier aircraft" and bases the statement on an analysis of "square feet of sail" . . . he blew it. I sat next to a guy for several years who wrote heavy duty software for autopilots that flew UAV's of all stripe from 80Kts to 500 Kts. He tapped simple-ideas to from my high school physics to describe how the airplane flies. I've been meaning to do an article on the physics of this maneuver and have some drawings done . . . somewhere on the hard drive. I'll see if I can dig them up and perhaps finish the article. But while you read the words of folks wrestling with the 'dreaded downwind turn' go to the POH data for your airplane and get one number. Target IAS for best glide angle. This is the speed at which your distance over the ground versus altitude lost is at a maximum. When folks are talking about the physics of flight, they're talking about airplanes that are being 'flown' . . . in other being controlled to conditions that maximize performance. This generally calls for a speed well above best rate of climb combined with a 270 degree turn at 45 degrees of bank into the crosswind to get pointed back toward the runway. When the engine quits with a runway close behind you, its easy for those performance numbers get obscured by other things running around in your head. It takes a Bob Hoover like attitude to first get the nose down to achieve best glide angle whether you are turning or not; stack in a 45-degree banked turn on top of really adds pucker factor. At speeds below best glide, lift/drag ratios can go into the toilet in a hurry. On of my most cherished flight instructors was checking me out in a Beech Flying Club A36 one day. After three or four by-the-book touch and goes he said "let me show you something." "Stay at pattern altitude until you're on final." "Uh, okay . . ." As I turned final I reached for the throttle . . . "Nope, not yet . . ." The runway disappeared under the nose and I reached for the throttle . . . "Nope, not yet . . . " A few seconds later he said, "Okay. Close the throttle and give me 75 MPH." I set it up and was amazed. Sink rate went to something around 1200 ft/min. A few seconds later I acquired a better short-final view of the runway and he said, "Power up to arrest your descent, push the nose down and give me 90 MPH over the numbers." After that, the landing proceeded normally. The point being that maneuvering around at speeds below best glide is where the airplane sinks fast even if you're not turning . . . faster still if you turn. Best glide is well above those speeds at which perturbations in IAS due to gusting can begin to eat into your energy margins for maneuvering. Best rate and particularly best angle of climb speeds have the nose really high with a commensurate boat-load of drag. Whether the airplane remains controllable just before contact with the ground isn't a matter of winds, it's a matter of altitude and the pilot's willingness/ability to EXCHANGE energy stored on that altitude for controllable airspeeds. Airspeeds that will bring you to the ground with energy to flare and keep the wheels attached to the airplane. The alternative is a 1000+ feet per minute descent rate, no energy to flare and a probability of having to eat your wheels. There are two magic numbers that drive your decision to turn around best glide speed and ground clearance KNOWN to be sufficient to the airplane's demands as determined by experiment and practice. Barry Schiff tells us how in this article. http://tinyurl.com/mo8wux4 Note that Barry mentions nothing about controllability hazards for having made a downwind turn. That's because the target approach speed for greatest probability of success is well above that where perturbations in wind velocity make any difference at all. See: http://tinyurl.com/kzr95lk http://tinyurl.com/m29yg5y http://tinyurl.com/k9y3z4y http://tinyurl.com/mmgmojr It's all about lift/drag ratios and energy budgets. If your choice of pitch angle is poor (IAS) or your stored energy (altitude) is lacking then it's a bit specious to drag 'hazards of downwind turns' into the discussion . . . things were probably not going to go well anyhow. You become a passenger in your airplane doing experiments with the controls. Bottom line is that EAA, of ALL organizations, should have folks with talents on a par with the honorable Mr. Schiff to vet their articles. http://tinyurl.com/mtn32qf -------------------------------------------------------------- The stall-spin outcome for attempting this maneuver comes from the natural unwillingness to push the nose down immediately upon loss of power. If you don't do that, the airplane slows, the controls go sloppy, sinkrate jumps up and the pilot succumbs to a powerful desire to raise the nose some more. A marginal energy budget (altitude and present velocity) is quickly squandered and has nothing to do with wind. As Barry mentions in the first article cited above, "The difference between success and failure is not only having sufficient altitude, but knowing how and when the turnaround maneuver can be performed with relative safety." I would add to that thought with the notion that few people will read Barry's article and become magically prepared to deal with the situation in real life. Practice, practice and a bit more practice goes a long way toward proficiency. In my early days of flying I spent hours in a Beech Skipper doing landings at the various and many grass strips around ICT during periods of adverse winds and turbulence. This was based on a comment by my instructor who said, "Someday you're going to find yourself over the airport down to less than ideal reserves for fuel and the task will be to deal with the winds you're given. Through those hours of getting to know my limits and those of my airplane, I lost my irrational fear of less than graceful landings and became more attentive to the physics of the task. The "dreaded downwind turn" is no different than "15 knots across the runway gusting to 25 with the thermals pounding the wings." If you don't set out to learn it then you'll be poorly equipped when you need it. Bob . . . Bob . . . ________________________________ Message 4 _____________________________________ Time: 05:48:56 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Fuselage as ground conductor At 07:04 PM 2/7/2014, you wrote: > >Bob N., et al.: > >When one builds an airplane with the starter and the battery some >distance apart, using the fuselage as a ground conductor is usually >(?) done. What is the resistance of a typical fuselage used in this >way? Can it carry 200A or so for the starter? > >What are your thoughts? The fuselage of a metal airplane taken as a whole is entirely capable of carrying and/all electrical system ground loads. As a rule of thumb, we used to consider the tip-to-tail resistance of an airplane like the Beechjet to be on the order of 0.001 ohms. How about attaching a high current conductor to the airframe? Imagine a 1" diameter disk of .032 aluminum being approached radially from all directions by an array of 0.032" square aluminum wires (roughly 20AWG equivalent). You can attach 3.14/.032 numbers of these wires to the edge of the disc for a total of 100 such wires. What's the current carrying capacity/ resistance of 100 strands of 20AWG in either aluminum or copper? The point of this exercise is to support the notion that the sheet resistance of just about any part of an airframe is very low; assuming all the pieces are well attached to each other, point-to-point resistance between any two locations on the airframe is also very low. Airplanes that get into conductor troubles with grounding over time are instances where a particular contiguous piece of aluminum has experienced the effects of moisture and high density electron flow at the joints where gas-tightness is lost. You can ground batteries at the tail to about any mechanically robust feature that is protected from the weather and stays dry. http://tinyurl.com/mcv3c9j I would ground a crankcase to the firewall sheet at a centralize grounding location like the B&C ground bus and not depend on engine mount for ground. Other than that, the only caveats for airframe grounding are the potential for injecting electrical system noise into vulnerable appliances by injudicious choices for grounding the victim . . . ground loops. Bob . . . ________________________________ Message 5 _____________________________________ Time: 07:31:24 AM PST US From: "Vern Little" Subject: Re: AeroElectric-List: Mac's theory defies the laws a physics This article purports to be a discussion of the physics, but ends up being a hand-waving exercise full of hokum. It suffers from a problem with changing frames of reference... the air, then the ground and tries to rationalize the effects. The best way to analyze the aircraft dynamics is with a single point of reference, the ground. When this is done, one can see *three* types of total energy at play. Two of the three energy types are obvious: kinetic energy due to the speed of the aircraft (over ground), potential energy due to the height of the aircraft in the gravitational field of the earth. What=99s the third one, you ask.....? Well, the moving mass of air (wind) appears in the calculations sort of like a horizontal gravitational field. Flying into the wind increases =98wind potential=99 energy with respect to the ground, flying downwind then converts this =98wind potential=99 into kinetic energy, just like descending converts gravitational potential energy into kinetic energy. Vern From: rayj Sent: Friday, February 07, 2014 3:44 PM Subject: Re: AeroElectric-List: Mac's theory defies the laws a physics Reminds me of an article that was in the Oct. 2013 (page 12) Sport Aviation. Doesn't anyone review these articles? Raymond Julian Kettle River, MN. "And you know that I could have me a million more friends, and all I'd have to lose is my point of view." - John Prine On 02/07/2014 04:26 PM, user9253 wrote: mailto:fransew@gmail.com Mac McClellan's theory seems to defy the laws a physics: http://goo.gl/VaZ4MS I think that he is wrong. Of course an airplane will lose airspeed in a level turn unless power is added, because part of the lift that was used to maintain altitude must be used to "lift" the airplane around a turn, overcoming inertia. I think that the only force the earth exerts on an airplane is gravity, no matter its relative motion. This is not electrically related. But there are some pretty smart people who lurk on the AeroElectric List. It will be interesting to read their opinions. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=418301#418301 ------------------------------------------------------------------------- ------- No virus found in this message. Checked by AVG - www.avg.com 02/07/14 ________________________________ Message 6 _____________________________________ Time: 07:55:43 AM PST US Subject: Re: AeroElectric-List: Mac's theory defies the laws a physics From: Jared Yates Maybe the chief editor could review the articles. Oh, wait... > Reminds me of an article that was in the Oct. 2013 (page 12) Sport Aviatio n. Doesn't anyone review these articles? > ________________________________ Message 7 _____________________________________ Time: 08:33:27 AM PST US Subject: AeroElectric-List: Timer circuit for led array From: Bob Verwey I found a Samsung 4 led ultrabrite strip that allegedly consumes 800 ma continuous. sounds high. Anyway, does anyone have a really simple circuit for pulsing this device. I am thinking of an array of 4 pulsing at the same time. Best.... Bob Verwey -- Best... Bob Verwey ________________________________ Message 8 _____________________________________ Time: 09:03:50 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Timer circuit for led array At 10:32 AM 2/8/2014, you wrote: >I found a Samsung 4 led ultrabrite strip that allegedly consumes 800 >ma continuous. sounds high. Anyway, does anyone have a really simple >circuit for pulsing this device. I am thinking of an array of 4 >pulsing at the same time. Let's see if I've interpreted your description correctly. 4 leds (I preseume white) to simply be pulsed in unison. Are they wired in series? Is there a current limiting resistor on the assembly (doubtful at that current level). What's the application? Landing light with attention-getting feature? Bob . . . ________________________________ Message 9 _____________________________________ Time: 09:06:34 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Essential Bus question Honestly Mr Nuckolls is the guy who puts my nose out of joint with the "kitchen sink" stuff. Just as Bob and this list has enabled me to design and build my dream traveling machine, I feel the need to defend all that has been enabled. Bob, I love you man! I value your advice, counsel and guidance above all others. This list and the people on it, especially folks like Kelly, are to die for. Just please stop calling my panel a "kitchen sink". Did I use that term . . . can you cite the posting? I promise I'll upgrade it, pare it down and streamline it with some excess $$$$ the next time I see the opportunity to do it. I'm sorry if you've found my contributions trying . . . but my friend . . . it's my job. I'll tell you a story . . . About 30 years ago I was enjoying attendance at one of Wichita's signature community events every fall; the annual chili cook-off. These were (and I think still are) vigorously contested events. The winners are chosen by counting the chill beans in a jar on the table at their cook-site in the park. Everyone who buys a ticket for the event is given a little bowl, an official tasting spoon and access to all the crackers they want. They also receive 10 beans to be dropped in what ever combination they choose into the contestant's jars as a means of voting by the tasting public. The caveat was that the top three winners had to post their recipes. I think the idea was that whoever won the coveted slots next year were thus encouraged not to have an identical or even largely similar recipe. I recall one winner's posting having probably the most complex recipe for ingredients I had ever seen . . . particularly in the range and ratio of spices. I asked the chef how he arrived at the necessity/ value for the ingredients. I don't recall his answer except that it wasn't very satisfying. I then hypothesized about his perceived ability to sample his work from two pots except that one ingredient would be eliminated from one of the pots. Did he think he could separate the altered batch from the golden batch. He allowed as how he could. I wish I had copied down the recipe. Needless to say his assertion was the source of no small degree of skepticism. I think it was Thomas Paine who extolled the virtues of simplicity as being less likely to become disordered and more easily set right if it should become disordered. I view my best contribution to the List in the role not unlike that of my most cherished bosses over the years who were also fond of Mr. Paine's sentiments. The simplest, lightest, least expensive solution to meeting design goals was the watchword. I can't tell you how many design reviews presented my work in front of a half dozen or more of my peers who were well armed with questions that produced some combination of three answers (1) the feature doesn't work, (2) the feature is unnecessary or (3) there's too many parts that drive up cost of ownership and dilutes value. All of the critics were armed with the customer's specification document. Those were never an activity to be feared or distrusted. What ever came out of the meeting was either 'golden' or blessed with suggestions for useful change. So yes, I may well give you a 'bad time' asking for justification and foundation for use of a particular part or architecture . . . with the same spirit and intent which I enjoyed over the years . . . a spirit and intent that persists to this day. Woke up this morning at 5:30 with an epiphany on a design problem I've been stirring in my head for a couple of weeks. I'm pretty sure my colleagues will approve . . . kicked a bunch of parts off the bill of materials (and a few hundred lines of code off the DO178 barge). I'll go see if they can poke any holes in it next week. If getting you little bent is a risk, I'll accept that. In the final analysis, what ever you decide to do poses little risk. You could produce an architecture that's simply pleasing to look at and fun to talk about. Used to see lots of those systems at OSH every year. Jim Bede's electrical honcho on the BD10J tried to enlist my services on such a project. Everything that happens to your design based on input from myself or others probably moves toward minimizing disorder and maximizing utility. That's a good thing. Bob . . . ________________________________ Message 10 ____________________________________ Time: 09:30:42 AM PST US From: D L Josephson Subject: AeroElectric-List: Re: Connectors and factories On 2/7/14 11:58 PM, AeroElectric-List Digest Server wrote: > * > > There are some folks who make very rugged yet > tiny connectors suited to the task. One in > particular is LEMO Ha! Yes, we are at the moment wrestling with a LEMO for a multichannel audio application. Some air carrier headsets also use LEMO. Remember, those connectors are made in the same region of Switzerland where they make watches. Very pretty and clever, but overkill for this. > Is the airplane likely to be stuck in a condition > so far out of trim that it's un-manageable with > elevated risks to aluminum and bone? I don't know that yet. > > How many times over the lifetime of the airplane > do you expect to open this connection for maintenance > or replacement of the actuator? There will be some configuration changes in the tail that may require a few removal/install cycles, and the tail trim is not the only place where this is needed. > By what > percentage of total task would labor go up if > those wires were simply soldered together and > heat-shrinked? That's the default, of course. One other alternative, that I have used in certificated aircraft projects over the years, is to use a PIDG knife disconnect connector per wire, each one in a vinyl sleeve and laced together. > > How can we free up some hours for our readers > to go buck a few more rivets as opposed to > getting wrapped around the decision axle on > the particular harness connector? I asked for discussion about the more general case of the several few-conductor breakaways in a small OBAM plane, such as for wing and cowling removal. I don't think it's necessary to get wrapped around any axle as many solutions will work, but thought there might be a consensus or a better idea than the ones I've had. Never mind, dlj04 out. ________________________________ Message 11 ____________________________________ Time: 09:31:10 AM PST US Subject: Re: AeroElectric-List: Timer circuit for led array From: Bob Verwey Apologies for not properly defining the issue ....the unit consists of four superbright LEds in a unit and is 12 v ready. So i want to take more than one of these units and create a flashing beacon light. Best .... Bob verwey On Saturday, February 8, 2014, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > nuckolls.bob@aeroelectric.com> > > At 10:32 AM 2/8/2014, you wrote: > > I found a Samsung 4 led ultrabrite strip that allegedly consumes 800 ma >> continuous. sounds high. Anyway, does anyone have a really simple circuit >> for pulsing this device. I am thinking of an array of 4 pulsing at the same >> time. >> > > Let's see if I've interpreted your > description correctly. 4 leds (I preseume > white) to simply be pulsed in unison. > > Are they wired in series? Is there a current > limiting resistor on the assembly (doubtful > at that current level). What's the application? > Landing light with attention-getting feature? > > > Bob . . . > > -- Best... Bob Verwey ________________________________ Message 12 ____________________________________ Time: 10:52:23 AM PST US From: Jeff Luckey Subject: Re: AeroElectric-List: Analyze This Peter,=0A=0AThanks for taking the time to review the drawing.- I really a ppreciate the insightful comments.=0A=0AMy responses are mixed-in with you questions.=0A=0AThx again,=0A=0A-Jeff=0A=0A=0A=0A__________________________ ______=0A From: Peter Pengilly =0ATo: aeroelectric- list@matronics.com =0ASent: Saturday, February 8, 2014 1:08 AM=0ASubject: R e: AeroElectric-List: Analyze This=0A =0A=0A=0AJeff,=0A=0AI would like a li ttle explanation of the basic operation. I'm=0A assuming both master swi tches on all the time, both batteries are=0A the same, throw one battery away each year. =0A=0AYes - both masters on for normal ops.- In addition ,=0Aat start-up by turning-on each master individually and=0Awatching the p ower indicators & volt meter you can=0Aconfirm that isolation diodes are fu nctioning properly.=0A=0A=0AIf alternator fails no simple load shedding is available, pilot must=0A select items individually (or have a check-list of what to switch=0A off). You're now wasting 2 amps (1 or each battery contactor).=0A=0ASee comment re load shedding below. My master =0Arelays d raw 200 mA each.=0A=0A=0AThink about the information you want the 2 shunts to provide, will=0A the do that, is there a better (simpler) way? As you already have=0A the power indicators, I would put the shunt in the alte rnator to bus=0A feed. Agree with comment about fusing (or current limit ing) feed to=0A batt B. I thought a current limiter was better placed in the=0A alternator output?=0A=0AI'm using a zero-center ammeter. With th e shunt in =0Aits current location it providesinfo on the health of =0Athe battery charging system when everything is=0Aworking properly.=0A=0AWhen th e alternator fails, it automatically becomes=0Aa load meter to aid the pilo t in load-shedding.- Exactly=0Athe info you want, exactly when you need i t.=0A=0AThere are fuses in alternator output leads. =0AAn over-voltage prot ection module will prevent alternator=0Arun-away.=0A=0AWith the shunt in th e alternator output, in the case that the=0Aalternator fails, you get no in formation about system load and =0Athat's when you need it the most in orde r to do=0Aeffective load-shedding.=0A=0A=0AI'm unsure what the 'K-...' mean s=0A=0A'K' is an industry standard abbreviation for relay/contactor=0A=0A =0A2 batteries will provide way more than 45 minutes operation on=0A bat tery power, even with a very full panel and no load shedding.=0A Therefo re system grossly exceeds design goal resulting in more=0A cost/weight t han required. Where does 45 minutes come from? FAR-23=0A requires 30 min utes, alternatively assume half or full fuel=0A endurance.=0A=0AThat wou ld depend upon battery selection and system load.=0AI did not provide any i nfo on this for my airplane.=0A45 minutes is my personal preference.=0A=0A =0ANo simple load shedding appears available - meets goal 2 (but=0A perh aps goal 1 & 2 are actually, survive any failure for 45=0A minutes with no pilot interaction)=0A=0A=0AI prefer to be in control of load-shedding ba sed upon the=0Asituation. I don't like the idea of having it predetermined =0Aby what is wired to an E-buss.=0A=0AIf I'm day VFR I may want to turn-of f lots of things.- If=0AI'm preparing for an Instrument approach, I may d ecide=0Anot to turn-off anything.=0A=0A =0ASystem seems more complex/costly than a 2 bus system would be. Seems=0A that goals 1 & 2 are weighted mu ch more highly than the others?=0A=0APerhaps simplicity/complexity is in th e eye of the beholder.=0AI think a single buss is simpler than multiple bus ses with =0Ainter-connection/bypass relays.=0A=0AThe buss-isolation diode u nits cost ~$20 each.- I'm willing=0Ato spend the extra $40.=0A=0A=0AIts y our airplane, build the system that meets your needs.=0A=0ARegards, Peter =0A=0A=0A=0AOn 02/02/2014 23:38, Jeff Luckey wrote:=0A=0AListers,=0A>=0A>At tached find a schematic (some people call them ladder=0A dia grams) of a design for the electrical system for my=0A RV-7A .- Below is a list of design goals, pros and cons.=0A Plea se take a look and provide engineering feedback.=0A>=0A>TIA=0A>=0A>=0A>Elec trical Systems Design Goals:=0A>1. fault tolerant - able to tolerate failur e of any=0A single component and fly for 45 min.=0A>2. easy to operate=0A>3. no avionics brown-out on engine start=0A>4. easy to repair =0A>5. comprised of standard, readily-available components =0A>6. cost effe ctive=0A>=0A>=0A>Pros:=0A>1. simplified operation - only 2 master switches =0A>2. simplified design - single buss=0A>=0A>3. no brown-out on engine sta rt=0A>4. automatic fail-over - no pilot interaction required; avionics won' t reset=0A>=0A>--- In the event a battery system suffers a failure, e ither an open circuit or a ground fault, the faulty=0A>--- system sim ply stops providing power to the buss and the remaining good system continu es to =0A>=0A>--- provide electricity without interruption.=0A>=0A> =0A>=0A>Cons:=0A>1. buss-isolation power diodes may require heat sinks=0A>2 ================ ________________________________ Message 13 ____________________________________ Time: 11:09:52 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Fuselage as ground conductor Good Afternoon Bob, Obviously, I am getting into this a bit late, but what about airplanes like the newer Bonanzas where all skins and stringers were painted prior to assembly? No doubt that the rivets when driven would spread to contact each joined skin, but would that be sufficient area to carry the current? Happy Skies, Old Bob In a message dated 2/8/2014 8:17:22 A.M. Central Standard Time, nuckolls.bob@aeroelectric.com writes: --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:04 PM 2/7/2014, you wrote: > >Bob N., et al.: > >When one builds an airplane with the starter and the battery some >distance apart, using the fuselage as a ground conductor is usually >(?) done. What is the resistance of a typical fuselage used in this >way? Can it carry 200A or so for the starter? > >What are your thoughts? The fuselage of a metal airplane taken as a whole is entirely capable of carrying and/all electrical system ground loads. As a rule of thumb, we used to consider the tip-to-tail resistance of an airplane like the Beechjet to be on the order of 0.001 ohms. How about attaching a high current conductor to the airframe? Imagine a 1" diameter disk of .032 aluminum being approached radially from all directions by an array of 0.032" square aluminum wires (roughly 20AWG equivalent). You can attach 3.14/.032 numbers of these wires to the edge of the disc for a total of 100 such wires. What's the current carrying capacity/ resistance of 100 strands of 20AWG in either aluminum or copper? The point of this exercise is to support the notion that the sheet resistance of just about any part of an airframe is very low; assuming all the pieces are well attached to each other, point-to-point resistance between any two locations on the airframe is also very low. Airplanes that get into conductor troubles with grounding over time are instances where a particular contiguous piece of aluminum has experienced the effects of moisture and high density electron flow at the joints where gas-tightness is lost. You can ground batteries at the tail to about any mechanically robust feature that is protected from the weather and stays dry. http://tinyurl.com/mcv3c9j I would ground a crankcase to the firewall sheet at a centralize grounding location like the B&C ground bus and not depend on engine mount for ground. Other than that, the only caveats for airframe grounding are the potential for injecting electrical system noise into vulnerable appliances by injudicious choices for grounding the victim . . . ground loops. Bob . . . ________________________________ Message 14 ____________________________________ Time: 03:25:10 PM PST US From: Bill Watson Subject: Re: AeroElectric-List: Essential Bus question On 2/8/2014 12:05 PM, Robert L. Nuckolls, III wrote: > > > Honestly Mr Nuckolls is the guy who puts my nose out of joint with the > "kitchen sink" stuff. Just as Bob and this list has enabled me to > design and build my dream traveling machine, I feel the need to defend > all that has been enabled. Bob, I love you man! I value your advice, > counsel and guidance above all others. This list and the people on > it, especially folks like Kelly, are to die for. Just please stop > calling my panel a "kitchen sink". > > Did I use that term . . . can you cite the posting? Well here is the one I remember: * *Match:* */#6/* *Message:* */#58841/* *Date:* */Jul 08, 2013/* *From:* */"Robert L. Nuckolls, III" /* *Subject:* /*Re: Low voltage indicator with dual alternators */ *(snip) * > >However, I normally start with the buses separated because if I go >parallel, the voltage drop causes my 3 MDFs to re-boot. How much 'stuff' do you have to turn on before engine start? On the Beech products we used to offer a mini-ebus switch that would let you fire up a comm radio directly from the battery. Your comm radio probably needs 0.2A receive, and maybe 1.5A transmit. A long winded pre-flight activity might need 1000 watt-seconds. I'm thinking that the bus from which all your 'kitchen sink' accessories is powered also powers the comm radio and you have no way to power up the comm radio independently? You might want to consider moving a comm radio to a battery bus and adding . . . *I hesitate to point out that you use the term generally to describe electro-whiz intensive panels but no matter. > > I promise I'll upgrade it, pare it down and streamline it with some > excess $$$$ the next time I see the opportunity to do it. > > I'm sorry if you've found my contributions trying . . . > but my friend . . . it's my job. And I'm on this list because you do it so well. No harm, no foul Mr Nuckolls! ________________________________ Message 15 ____________________________________ Time: 03:28:42 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Mac's theory defies the laws a physics At 09:55 AM 2/8/2014, you wrote: >Maybe the chief editor could review the articles. Oh, wait... > >>Reminds me of an article that was in the Oct. 2013 (page 12) Sport >>Aviation. Doesn't anyone review these articles? It seems that Mr. McCellan has skipped across the wave-tops on an incident we discussed here on the List as I recall . . . http://tinyurl.com/o3j2bxh I've maintained that the incident and several others like it http://tinyurl.com/ky7szec were absolutely not electrical system failures but instead failures on the part of owner/operator to assemble and maintain the system components within the limits of their performance. A car that goes over the edge of a cliff after blowout of a bald tire did not suffer that end due to 'tire failure' . . . yes the tire demonstrated it's inability to meet design goals after being neglected/abused by its owner . . . but it was simply the inevitable icing on a cake that was baked hours, days even perhaps months earlier. Bob . . . ________________________________ Message 16 ____________________________________ Time: 04:52:45 PM PST US From: Kelly McMullen Subject: Re: AeroElectric-List: Essential Bus question I don't know about a GNS-430, but the GTN-650 I have uses around 2.8 amps for the nav side and maybe .8 for the com side when in receive mode. My Dynon Skyview screens use about 3 amps each. My SL-30 is under 2 amps in receive mode for com and nav together. So the governing draw will be how much current the EFIS needs and how much the certified GPS needs. It seems odd that a certified GPS doesn't let you program and save a flight plan in non-volatile memory as most portable GPS units allow. If it doesn't, then an isolated backup battery powering just the essential items would seem to be required. My antique Northstar M3 GPS allows storing flight plans as long as the soldered in keep alive battery is good. (no longer is). On 2/8/2014 4:23 PM, Bill Watson wrote: > On 2/8/2014 12:05 PM, Robert L. Nuckolls, III wrote: >> >> >> Honestly Mr Nuckolls is the guy who puts my nose out of joint with >> the "kitchen sink" stuff. Just as Bob and this list has enabled me >> to design and build my dream traveling machine, I feel the need to >> defend all that has been enabled. Bob, I love you man! I value your >> advice, counsel and guidance above all others. This list and the >> people on it, especially folks like Kelly, are to die for. Just >> please stop calling my panel a "kitchen sink". >> >> Did I use that term . . . can you cite the posting? > Well here is the one I remember: > * > *Match:* */#6/* > *Message:* */#58841/* > > *Date:* */Jul 08, 2013/* > > *From:* */"Robert L. Nuckolls, III" /* > > *Subject:* /*Re: Low voltage indicator with dual alternators > */ > > *(snip) > * > > > >However, I normally start with the buses separated because if I > go >parallel, the voltage drop causes my 3 MDFs to re-boot. How > much 'stuff' do you have to turn on before engine start? On the > Beech products we used to offer a mini-ebus switch that would let > you fire up a comm radio directly from the battery. Your comm > radio probably needs 0.2A receive, and maybe 1.5A transmit. A long > winded pre-flight activity might need 1000 watt-seconds. I'm > thinking that the bus from which all your 'kitchen sink' > accessories is powered also powers the comm radio and you have no > way to power up the comm radio independently? You might want to > consider moving a comm radio to a battery bus and adding . . . > *I hesitate to point out that you use the term generally to describe > electro-whiz intensive panels but no matter. >> >> I promise I'll upgrade it, pare it down and streamline it with some >> excess $$$$ the next time I see the opportunity to do it. >> >> I'm sorry if you've found my contributions trying . . . >> but my friend . . . it's my job. > And I'm on this list because you do it so well. No harm, no foul Mr > Nuckolls! > > * > > > * ________________________________ Message 17 ____________________________________ Time: 06:00:24 PM PST US Subject: Re: AeroElectric-List: Essential Bus question From: Tim Andres The 430w will allow storing a limited number of flight plans, IIRC 10, but if not using it again I hesitate to replace one of the ones I do use frequently with one I won't use again. Tim > On Feb 8, 2014, at 4:51 PM, Kelly McMullen wrote: > > > I don't know about a GNS-430, but the GTN-650 I have uses around 2.8 amps for the nav side and maybe .8 for the com side when in receive mode. > My Dynon Skyview screens use about 3 amps each. My SL-30 is under 2 amps in receive mode for com and nav together. So the governing draw will be how much current the EFIS needs and how much the certified GPS needs. > It seems odd that a certified GPS doesn't let you program and save a flight plan in non-volatile > memory as most portable GPS units allow. If it doesn't, then an isolated backup battery powering just the essential items would seem to be required. > My antique Northstar M3 GPS allows storing flight plans as long as the soldered in keep alive battery is good. (no longer is). > >> On 2/8/2014 4:23 PM, Bill Watson wrote: >>> On 2/8/2014 12:05 PM, Robert L. Nuckolls, III wrote: >>> >>> Honestly Mr Nuckolls is the guy who puts my nose out of joint with the "kitchen sink" stuff. Just as Bob and this list has enabled me to design and build my dream traveling machine, I feel the need to defend all that has been enabled. Bob, I love you man! I value your advice, counsel and guidance above all others. This list and the people on it, especially folks like Kelly, are to die for. Just please stop calling my panel a "kitchen sink". >>> >>> Did I use that term . . . can you cite the posting? >> Well here is the one I remember: >> * >> *Match:* */#6/* >> *Message:* */#58841/* >> >> *Date:* */Jul 08, 2013/* >> >> *From:* */"Robert L. Nuckolls, III" /* >> >> *Subject:* /*Re: Low voltage indicator with dual alternators */ >> >> *(snip) >> * >> >> > >However, I normally start with the buses separated because if I >> go >parallel, the voltage drop causes my 3 MDFs to re-boot. How >> much 'stuff' do you have to turn on before engine start? On the >> Beech products we used to offer a mini-ebus switch that would let >> you fire up a comm radio directly from the battery. Your comm >> radio probably needs 0.2A receive, and maybe 1.5A transmit. A long >> winded pre-flight activity might need 1000 watt-seconds. I'm >> thinking that the bus from which all your 'kitchen sink' >> accessories is powered also powers the comm radio and you have no >> way to power up the comm radio independently? You might want to >> consider moving a comm radio to a battery bus and adding . . . *I hesitate to point out that you use the term generally to describe electro-whiz intensive panels but no matter. >>> >>> I promise I'll upgrade it, pare it down and streamline it with some excess $$$$ the next time I see the opportunity to do it. >>> >>> I'm sorry if you've found my contributions trying . . . >>> but my friend . . . it's my job. >> And I'm on this list because you do it so well. No harm, no foul Mr Nuckolls! >> >> * >> >> >> * > > > > > ________________________________ Message 18 ____________________________________ Time: 08:35:36 PM PST US Subject: AeroElectric-List: Timer circuit for led array From: Bob Verwey I found a Samsung 4 led ultrabrite strip that allegedly consumes 800 ma continuous. sounds high. Anyway, does anyone have a really simple circuit for pulsing this device. I am thinking of an array of 4 pulsing at the same time. Best.... Bob Verwey -- Best... Bob Verwey ________________________________ Message 19 ____________________________________ Time: 08:35:37 PM PST US Subject: Re: AeroElectric-List: Mac's theory defies the laws a physics From: Richard Girard I honestly had to read Mac's blog a couple of times to overcome my disbelief inertia. With this blog and that idiotic "sail area" article, I have to seriously think about my relationship to EAA. That they claim to be an organization concerned about aviation safety and then allow such drivel to be published is just unbelievable. As I said in my comment to Mac's blog, it's embarrassing, simply embarrassing. Rick Girard do not archive On Fri, Feb 7, 2014 at 4:26 PM, user9253 wrote: > > Mac McClellan's theory seems to defy the laws a physics: > http://goo.gl/VaZ4MS > I think that he is wrong. Of course an airplane will lose airspeed in a > level turn unless power is added, because part of the lift that was used to > maintain altitude must be used to "lift" the airplane around a turn, > overcoming inertia. I think that the only force the earth exerts on an > airplane is gravity, no matter its relative motion. > This is not electrically related. But there are some pretty smart people > who lurk on the AeroElectric List. It will be interesting to read their > opinions. > Joe > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=418301#418301 > > -- Zulu Delta Mk IIIC Thanks, Homer GBYM It isn't necessary to have relatives in Kansas City in order to be unhappy. - Groucho Marx ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.