---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 10/08/18: 15 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:12 AM - Re: Rear battery earthing structure (Neil Parkinson) 2. 06:39 AM - Re: Re: Question: can these wires be put in one wire bundle? (FLYaDIVE) 3. 09:04 AM - Re: Rear battery earthing structure (Robert L. Nuckolls, III) 4. 09:47 AM - Re: Re: Question: can these wires be put in one wire bundle? (Robert L. Nuckolls, III) 5. 10:20 AM - Re: Re: Question: can these wires be put in one wire bundle? (Robert L. Nuckolls, III) 6. 01:19 PM - Re: Rear battery earthing structure (Bill Watson) 7. 06:10 PM - A brown-out alternative? (Robert L. Nuckolls, III) 8. 06:19 PM - B lead circuit breaker (Ron Burnett) 9. 06:48 PM - Re: A brown-out alternative? (Art Zemon) 10. 06:50 PM - Re: A brown-out alternative? (Roger) 11. 06:51 PM - Re: B lead circuit breaker (Art Zemon) 12. 07:11 PM - Re: A brown-out alternative? (Charlie England) 13. 07:26 PM - Re: B lead circuit breaker (Ron Burnett) 14. 08:37 PM - Re: B lead circuit breaker (Robert L. Nuckolls, III) 15. 10:55 PM - Re: A brown-out alternative? (Eric Page) ________________________________ Message 1 _____________________________________ Time: 12:12:49 AM PST US From: Neil Parkinson Subject: Re: AeroElectric-List: Rear battery earthing structure Thanks Bob. Yes in the rear I was planning on installing the remote boxes for the transp onder , com , etc. So yes Audio and digital signals going back and forth ? How that effect the e arth situation ? Neil > On 8 Oct 2018, at 00:22, Robert L. Nuckolls, III wrote: > > At 05:46 PM 10/7/2018, you wrote: enworld.com> >> >> Hi Everybody. >> >> I=99m building an RV8 with a rear battery location. >> >> Can I please have some advice on the earthing structure . Can I just eart h the battery to the structure in the rear , then take it the common earth a t the panel ? Or is it worth running some asw2 cable to earth the panel , or the engine ?? > > Ground battery locally > > http://aeroelectric.com/Pictures/Batteries/Battery_Install_OBrien_3.jpg > http://aeroelectric.com/Pictures/Grounding/Local_Battery_Grounds_1.jpg > > Install ground bus on firewall. > > http://aeroelectric.com/Pictures/Grounding/Forest_of_Tabs_Ground_Kit.pdf > http://aeroelectric.com/Pictures/Grounding/gnd_bus.jpg > > > Run braided-flat-wire > from crankcase to firewall ground stud. > > http://aeroelectric.com/Pictures/Grounding/Braided%20Copper%20Bond%20Strap s.jpg > > > >> I will have some rear avionics equipment , should I run the earth from th e panel to these ? Or just tap of the structure locally ? > > What kind of avionics? Anything with audio or digital > signal leads? > > Bob . . . ________________________________ Message 2 _____________________________________ Time: 06:39:03 AM PST US From: FLYaDIVE Subject: Re: AeroElectric-List: Re: Question: can these wires be put in one wire bundle? Rick: You did right by mounting the Magnetometer in the tail. As I said I have installed four G5 systems. Of course I tried the wing as my first location on my first job. It was difficult to run the wires and there were other problems: a> If you go far out on the wing to get away from the noise of the engine compartment you become too close to the wing tip strobe. b> And just the opposite when you move the Magnetometer closer to the engine compartment to get away from the noise of the wing tip strobe, you get too close to the engine compartment noise. Ya can't win for loosing! On Sun, Oct 7, 2018 at 9:47 PM Rick Beebe wrote: > On 10/7/2018 2:41 PM, FLYaDIVE wrote: > > Is the G5 the victim or > >> the antagonist? >> > Barry - It is the VICTIM, as the G5 has a Noise Testing program built into > them. > The big issue of noise, is because it has a remote mounted Magnetometer. > > But I don't think it's fair to say the G5 is susceptible to noise. > Barry - You DON'T! It is totally fair to call a spade a spade. They are very susceptible to noise. So much so that Garmin installed a Noise Detecting Program. How can you not say they ARE susceptible? You even make that statement ;-p > By their nature, magnetometers are sensitive beasts. > > --Rick > Barry - So, you did Very Good mounting it in the tail. It was probably even easier to install and will be easier to access to work on - Well, I don't know your plane but it is in the planes I have installed them in. Rick, did you notice there is a wire length [sort of] limit for the Magnetometer? They want you to keep it 15 ft or less. That was a hard STRETCH of the wire situation. There is another issue that has snuck its head into our 'modern' aviation world. Things Change - Way Back in Bob N.'s day of King Air and simple bundles of wires with ALL cables bundled together is No Longer. We have new items entering the market place every day and many produce noise. We have to do what ever we can to reduce and eliminate all sorts of noise. Here on this list we spoke about the modern noise from LED's. It's not going away. Simple procedures like twisting power wires may help. And, if it does not, it ain't gaun-a hurt! I use Red and Black wires constantly to show the power wires, it just makes things easier. I also use Blue, Yellow, Green and White. :-D No Chartreuse! It clashes with my eyes. Barry ________________________________ Message 3 _____________________________________ Time: 09:04:32 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Rear battery earthing structure At 02:09 AM 10/8/2018, you wrote: >Thanks Bob. > >Yes in the rear I was planning on installing the remote boxes for >the transponder , com , etc. > >So yes Audio and digital signals going back and forth ? How that >effect the earth situation ? > >Neil Follow the wiring diagrams in the installation manuals. Remotely mounted black-boxes have been around for a VERY LONG TIME . . . WWII radios were almost always remotely mounted . . . that vacuum tube stuff just wouldn't fit into an already tight cockpit. Signal and power management for such installations were well understood and accounted for in the installation instructions. Having said that, it is not difficult to design such systems to be goof-proof . . . difficult to even deliberately cause a noise issue. The vast majority of noise problems I've encountered in light aircraft were in the audio system with improper management of grounds to microphones and headset jacks. Bob . . . ________________________________ Message 4 _____________________________________ Time: 09:47:41 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Question: can these wires be put in one wire bundle? > >There is another issue that has snuck its head >into our 'modern' aviation world.=C2 Things >Change - Way Back in Bob N.'s day of King Air >and simple bundles of wires with ALL cables >bundled together is No Longer.=C2 We have new >items entering the market place every day and >many produce noise.=C2 We have to do what ever we >can to reduce and eliminate all sorts of >noise.=C2 Here on this list we spoke about the >modern noise from LED's.=C2 It's not going away. Barry, your talking about hardware that would not be allowed onto a production airplane . . . twisting power wires never helped any noise issue. It has mitigated a magnetic interference situation with windshield mounted compasses . . . twisting the wires (or using a shielded wire for outbound and return) on the light bulb reduced heading errors from that source to zero. I have designed, built, qualified and integrated dozens of appliances onto type certificated airplanes with the notion that EVERY qualified device should live happily with all other qualified devices with NO special attention on the part of the installer/system integrator with respect to noise. Installation instructions were expected to include special considerations with respect to environment, orientation, mechanical mounting, etc. But special considerations with respect to noise would be hard to sell to the ACO. One of the last noise issues I worked at Beech was a newly qualified cabin HVAC system wherein the rear mounted blower hosed the ADF. Ran the blower in our lab and found it to be exceedingly noisy. This device was recently 'qualified' by a lab in Dallas. I drove down and visited the lab. Looked a their test set up and talked with the test technician. Looked at his test data plot. "Wow", says he, "this the the quietest motor I've ever tested". To be sure the plots didn't rise off the receiver's noise floor! We poked around the EMC test cell and found that the coax through the wall to their conducted noise transformer had been disconnected . . . Fortunately, there were only about a dozen products they had erroneously holy watered in that test cell . . easy to spot in the test data. The test technician wasn't experienced enough to know that the noise was never zero. It just had to be below a pass/fail line. We had a dozen systems in the field. Modifying the blower would call for re-qualification. Made a midnight run to Captor Corporation where a fellow gray-beard and I crafted a filter-connector to go on the end of the harness that mated with the blower. I had worked with this fellow for decades on a host of filter designs but this was the first time we met face to face and hammered out a solution together. He was semi-retired and I was getting close . . . it was a great experience. Emacs! Had to do this kind of thing on another airplane where vintage starter-generator controllers (never qualified to modern design philosophies) needed a bunch of capacitors installed under the connector back shell. Emacs! These noise problems were the result of poorly designed and/or qualified devices. The fact that they were fielded made it necessary to craft 'band aids' to bring them into compliance. But these are very rare circumstances. The noises from products you allude to would not be mitigated by line twisting or repositioning of wires. Adding some filtering might do the job . . . we've done that on several devices discussed here on the List. Yes, many of my anecdotes have some age on them . . . been doing this for a long time. But the SCIENCE hasn't materially changed in my lifetime. And by the way, production airplanes are generally wired with white wire. Bob . . . ________________________________ Message 5 _____________________________________ Time: 10:20:24 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Re: Question: can these wires be put in one wire bundle? At 11:01 PM 10/7/2018, you wrote: > >Noise problems are sometimes present no matter how careful the builder has >been. That is why I read this forum, just to get ideas how to chase them. >When a friend ask me for ideas on how to find an intermittent source of >noise in his GlassStar, I gave him some ideas based on what I had learned >here. He had no luck and was just ready to give up when he accidently >noticed his HOBBS meter was running intermittently. He had a standard >arrangement where a switch in the oil pressure line turned on the HOBBS >meter so it recorded actual engine run time. When he replaced the oil >pressure switch that activated the HOBBS meter, the intermittent noise went >away. That was a total accidental situation. I doubt anyone would have >suspected a bad set of points in an oil pressure switch of causing the >problem. > >You learn something new every day if you just pay attention to what you can >learn by other's experiences. Interesting anecdote! Thanks for sharing. Yes, MOST noise problems are vexing . . . often difficult to analyze and fix. This is because they are rare and seldom follow a historical script. Given that all qualified appliances are 99.99% guaranteed to live in one happy community, issues that do arise tend to be one-of, weird little thing that nobody has seen before and may never see again. This is why prophylactics beyond the legacy catalog of good practices are of no demonstrable value. I am reminded of a call I received from one of my seminar attendees about 25 years ago. He described a litany of techniques he had applied to his Long-Ez with the goal of mitigating noise issues. He had shielded all his wires, separated certain wires from others and had crafted a 'ground system' that was difficult to visualize from the conversation. I was somewhat astounded and asked, "What kind of noise problem do you have?" "Oh, no problem," says he, "I haven't flown the airplane yet. Just want to make sure I've got all the bases covered." I suggested that he speak with builders already flying who are happy with their installations. I further suggested that he would save some weight, bulk and complexity by pulling out all of what he'd already put in and start over. If he did encounter a noise problem, it would most likely be easy to fix. Had occasion to communicate with him years later and he was happily flying a lighter, simpler system. Bob . . . ________________________________ Message 6 _____________________________________ Time: 01:19:27 PM PST US Subject: Re: AeroElectric-List: Rear battery earthing structure From: Bill Watson On 10/7/2018 7:22 PM, Robert L. Nuckolls, III wrote: > At 05:46 PM 10/7/2018, you wrote: >> >> >> Hi Everybody. >> >> Im building an RV8 with a rear battery location. >> >> Can I please have some advice on the earthing structure . Can I just >> earth the battery to the structure in the rear , then take it the >> common earth at the panel ? Or is it worth running some asw2 cable to >> earth the panel , or the engine ?? > > Ground battery locally > > http://aeroelectric.com/Pictures/Batteries/Battery_Install_OBrien_3.jpg > http://aeroelectric.com/Pictures/Grounding/Local_Battery_Grounds_1.jpg > > Install ground bus on firewall. > > http://aeroelectric.com/Pictures/Grounding/Forest_of_Tabs_Ground_Kit.pdf > http://aeroelectric.com/Pictures/Grounding/gnd_bus.jpg > > > > Run braided-flat-wire > from crankcase to firewall ground stud. > > http://aeroelectric.com/Pictures/Grounding/Braided%20Copper%20Bond%20Straps.jpg > > >> I will have some rear avionics equipment , should I run the earth >> from the panel to these ? Or just tap of the structure locally ? > > What kind of avionics? Anything with audio or digital > signal leads? > > Bob . . . > To OP: I have an RV10 with a 2 rear batteries, a ground bus on firewall and a braided flat wire from crankcase to firewall ground stud. No problems (7 years flying) In addition I have a variety of boxes installed in rear including Navworx ADSB, strobe unit, Magnetometers (sic), and ELT. I followed the installation instructions as Bob suggested. No problems. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 7 _____________________________________ Time: 06:10:14 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: A brown-out alternative? I mentioned a few days ago that I thought I had yet another solution to the perennial brown-out gremlin. This discussion has been going on for quite some time and many hours have been expended on a search for the practical if not elegant solution. Background: It seems a number of entrepreneurial suppliers to the OBAM aircraft industry have introduced devices with desirable features at prices attractive to the community. With the advent of PM starters (gawd awful inrush currents) and a quest for smaller and lighter batteries, the initial current draw during cranking would depress the battery voltage to some value where these devices would reset. I think Greg's Blue Mountain EFIS system was one of the first victims of the dreaded CBOT(cranking brown out transient). Many of the first victims were candidates for simple energy storage networks comprised of super-capacitors. Seems their current draw was so small and the CBOT so short that the capacitors would fill in the energy gap. Over the years it seems that the desire for more energy over longer CBOTs made the capacitor-storage solution marginal if not impractical. Then came some battery based products that offered both heavier current support during CBOT but let you do some things like run some electro-whizzies for some time before cranking the engine. Only down-side being it adds a battery to the airplane. Batteries are like house plants . . . mis-treat them slightly and they will probably recover . . . mis-treat them badly and they're T.U. Some batteries were ensconced within an electronic protective shell to reduce probability of mis-treatment. Good. But it adds to cost. Then there's the issue of service life. ALL batteries of any type used for any task on the airplane eventually need replacement. This feature DEMANDS preventative maintenance attention from the operator for monitoring condition of the battery(ies) with go/no-go criteria for replacement. I've done dozens of FMEA and reliability studies where adding batteries to the system may have offered builders some warm-n-fuzzy feelings . . . even to the degree that they quit worrying about the ship's main battery. Given that a properly maintained battery is the single most reliable source of energy on the airplane, it did not make sense to me that adding more battery(ies) was more desirable than simply taking care of the battery you already have . . . and doing the energy studies to see that its capacity was adequate to all anticipated flight conditions. So, with the one-battery per airplane design goal in mind and CBOTs still lurking in the wings, I would offer the architecture below for the List's consideration: Emacs! DC to DC up-converters are jelly-bean parts. Dozens of candidates are available for less than $10 which will boost 10 or so volts, depressed battery to 14v . . . well above the roll-over voltage for potential CBOT victims. With the architecture shown above, the e-bus boost feature is available only while the e-bus alternate feed switch is in the NORMAL position . . . and only while power is being applied to the starter contactor via crew controlled push button. The DC/DC converter can be of any pedigree since (1) it's never active during normal ops (EMC issues disappear) (2) functionality is pre-flight tested every flight cycle. (3) It is not a safety of flight issue since it's only active for tens of milliseconds during cranking -AND- failure of the converter does not disable any accessory neeed for comfortable termination of flight. (4) Since it is active for perhaps a second each flight cycle and average utilization of the light aircraft is less than 100 fligh cycles per year, the service life of these devices should exceed lifetime of the airframe. If there is a 'downside' to this approach, I suppose that it causes the crew to 'load' the ship's battery for preflight ops such as ATIS and clearance collection. But recall that we're assuming that the ship's battery will be sized and maintained to meet design goals. In the normal world, cranking the engine takes perhaps 5% of battery capacity. Preflight ops of electro-whizzies should require no more than that. That energy will be replaced in the first few minutes of flight. I humbly suggest that the technique cited above will deal with 100% of CBOT issues at zero cost of ownership beyond initial purchase and installation of the system and zero impact on system reliability and performance. It also encourages the owner to conduct due diligence in the maintenance of the ship's battery since there are NO standby batteries tending to lull one into a false sense of system reliability. Cogent arguments pro and con are most welcome. Bob . . . ________________________________ Message 8 _____________________________________ Time: 06:19:18 PM PST US From: Ron Burnett Subject: AeroElectric-List: B lead circuit breaker I have a Plane Power Alternator on my RV-6A and lately with the Aero Flash strobes on at some point the B lead CB will pop. It does reset. Today I flew a 2 leg cross country for 4 hours total, all with the strobes off after the popping event 2 minutes into the flight. How would I determine if their is a problem with the strobes that might cause this problem? Thanks for any hints. Ron Burnett May you have the Lord's blessings today! Sent from my iPad ________________________________ Message 9 _____________________________________ Time: 06:48:35 PM PST US From: Art Zemon Subject: Re: AeroElectric-List: A brown-out alternative? Bob, That looks very clever. I think that it will work. Is my logic here correct? For my plane, which has two alternators and no endurance bus, I would create an "EFIS" bus, running only the EFIS, and fed via two diodes, one to the main bus and the second to the DC/DC upverter. For those of us who don't live and breathe this stuff, can you post a few typical part numbers for the upverter and the diodes? Or typical specs? Thank you for attending to this issue. -- Art Z. On Mon, Oct 8, 2018 at 8:28 PM Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > So, with the one-battery per airplane design goal in > mind and CBOTs still lurking in the wings, I would offer > the architecture below for the List's consideration: > > > [image: Emacs!] > > -- https://CheerfulCurmudgeon.com/ *"We do not see the world as it is. We see the world as we are."* ________________________________ Message 10 ____________________________________ Time: 06:50:25 PM PST US From: Roger Subject: RE: AeroElectric-List: A brown-out alternative? From: Robert L. Nuckolls, III Sent: Monday, October 8, 2018 9:12 PM Subject: AeroElectric-List: A brown-out alternative? I mentioned a few days ago that I thought I had yet another solution to the perennial brown-out gremlin. This discussion has been going on for quite some time and many hours have been expended on a search for the practical if not elegant solution. Background: It seems a number of entrepreneurial suppliers to the OBAM aircraft industry have introduced devices with desirable features at prices attractive to the community. With the advent of PM starters (gawd awful inrush currents) and a quest for smaller and lighter batteries, the initial current draw during cranking would depress the battery voltage to some value where these devices would reset. I think Greg's Blue Mountain EFIS system was one of the first victims of the dreaded CBOT(cranking brown out transient). Many of the first victims were candidates for simple energy storage networks comprised of super-capacitors. Seems their current draw was so small and the CBOT so short that the capacitors would fill in the energy gap. Over the years it seems that the desire for more energy over longer CBOTs made the capacitor-storage solution marginal if not impractical. Then came some battery based products that offered both heavier current support during CBOT but let you do some things like run some electro-whizzies for some time before cranking the engine. Only down-side being it adds a battery to the airplane. Batteries are like house plants . . . mis-treat them slightly and they will probably recover . . . mis-treat them badly and they're T.U. Some batteries were ensconced within an electronic protective shell to reduce probability of mis-treatment. Good. But it adds to cost. Then there's the issue of service life. ALL batteries of any type used for any task on the airplane eventually need replacement. This feature DEMANDS preventative maintenance attention from the operator for monitoring condition of the battery(ies) with go/no-go criteria for replacement. I've done dozens of FMEA and reliability studies where adding batteries to the system may have offered builders some warm-n-fuzzy feelings . . . even to the degree that they quit worrying about the ship's main battery. Given that a properly maintained battery is the single most reliable source of energy on the airplane, it did not make sense to me that adding more battery(ies) was more desirable than simply taking care of the battery you already have . . . and doing the energy studies to see that its capacity was adequate to all anticipated flight conditions. So, with the one-battery per airplane design goal in mind and CBOTs still lurking in the wings, I would offer the architecture below for the List's consideration: DC to DC up-converters are jelly-bean parts. Dozens of candidates are available for less than $10 which will boost 10 or so volts, depressed battery to 14v . . . well above the roll-over voltage for potential CBOT victims. With the architecture shown above, the e-bus boost feature is available only while the e-bus alternate feed switch is in the NORMAL position . . . and only while power is being applied to the starter contactor via crew controlled push button. The DC/DC converter can be of any pedigree since (1) it's never active during normal ops (EMC issues =C2-=C2-=C2- disappear) (2) functionality is pre-flight tested every flight =C2-=C2-=C2- cycle. (3) It is not a safety of flight issue since it's =C2-=C2-=C2- only active for tens of milliseconds during =C2-=C2-=C2- cranking -AND- failure of the converter does =C2-=C2-=C2- not disable any accessory neeed for comfortable =C2-=C2-=C2- termination of flight. (4) Since it is active for perhaps a second each =C2-=C2-=C2- flight cycle and average utilization of the =C2-=C2-=C2- light aircraft is less than 100 fligh cycles =C2-=C2-=C2- per year, the service life of these devices =C2-=C2-=C2- should exceed lifetime of the airframe. If there is a 'downside' to this approach, I suppose that it causes the crew to 'load' the ship's battery for preflight ops such as ATIS and clearance collection. But recall that we're assuming that the ship's battery will be sized and maintained to meet design goals. In the normal world, cranking the engine takes perhaps 5% of battery capacity. Preflight ops of electro-whizzies should require no more than that. That energy will be replaced in the first few minutes of flight. I humbly suggest that the technique cited above will deal with 100% of CBOT issues at zero cost of ownership beyond initial purchase and installation of the system and zero impact on system reliability and performance. It also encourages the owner to conduct due diligence in the maintenance of the ship's battery since there are NO standby batteries tending to lull one into a false sense of system reliability. Cogent arguments pro and con are most welcome. =C2- Bob . . . Am I correct in assuming that the right hand side of the start push button should be tied through a fuse to the main bus? Roger ________________________________ Message 11 ____________________________________ Time: 06:51:49 PM PST US From: Art Zemon Subject: Re: AeroElectric-List: B lead circuit breaker Ron, Do you have a voltmeter in the plane? I am guessing that the circuit breaker is popping because the voltage is going too high. Maybe a voltage regulator problem. -- Art Z. On Mon, Oct 8, 2018 at 8:34 PM Ron Burnett wrote: > ronburnett@charter.net> > > I have a Plane Power Alternator on my RV-6A and lately with the Aero Flash > strobes on at some point the B lead CB will pop. It does reset. Today I > flew a 2 leg cross country for 4 hours total, all with the strobes off > after the popping event 2 minutes into the flight. How would I determine if > their is a problem with the strobes that might cause this problem? -- https://CheerfulCurmudgeon.com/ *"We do not see the world as it is. We see the world as we are."* ________________________________ Message 12 ____________________________________ Time: 07:11:50 PM PST US Subject: Re: AeroElectric-List: A brown-out alternative? From: Charlie England On 10/8/2018 8:09 PM, Robert L. Nuckolls, III wrote: > I mentioned a few days ago that I thought I > had yet another solution to the perennial brown-out > gremlin. > > This discussion has been going on for quite some time > and many hours have been expended on a search for the > practical if not elegant solution. > > Background: > > It seems a number of entrepreneurial suppliers to the > OBAM aircraft industry have introduced devices with desirable > features at prices attractive to the community. > > With the advent of PM starters (gawd awful inrush currents) > and a quest for smaller and lighter batteries, the initial > current draw during cranking would depress the battery voltage > to some value where these devices would reset. I think Greg's > Blue Mountain EFIS system was one of the first victims of the > dreaded CBOT(cranking brown out transient). > > Many of the first victims were candidates for simple > energy storage networks comprised of super-capacitors. Seems > their current draw was so small and the CBOT so short that > the capacitors would fill in the energy gap. > > Over the years it seems that the desire for more energy > over longer CBOTs made the capacitor-storage solution > marginal if not impractical. > > Then came some battery based products that offered > both heavier current support during CBOT but let you > do some things like run some electro-whizzies for some time > before cranking the engine. > > Only down-side being it adds a battery to the airplane. > > Batteries are like house plants . . . mis-treat them slightly > and they will probably recover . . . mis-treat them badly > and they're T.U. Some batteries were ensconced within an > electronic protective shell to reduce probability of > mis-treatment. Good. But it adds to cost. > > Then there's the issue of service life. ALL batteries of > any type used for any task on the airplane eventually > need replacement. This feature DEMANDS preventative maintenance > attention from the operator for monitoring condition of > the battery(ies) with go/no-go criteria for replacement. > > I've done dozens of FMEA and reliability studies where > adding batteries to the system may have offered builders > some warm-n-fuzzy feelings . . . even to the degree that > they quit worrying about the ship's main battery. > > Given that a properly maintained battery is the single > most reliable source of energy on the airplane, it did > not make sense to me that adding more battery(ies) was > more desirable than simply taking care of the battery > you already have . . . and doing the energy studies > to see that its capacity was adequate to all anticipated > flight conditions. > > So, with the one-battery per airplane design goal in > mind and CBOTs still lurking in the wings, I would offer > the architecture below for the List's consideration: > > > Emacs! > > DC to DC up-converters are jelly-bean parts. Dozens > of candidates are available for less than $10 which > will boost 10 or so volts, depressed battery to 14v . . . > well above the roll-over voltage for potential CBOT > victims. > > With the architecture shown above, the e-bus boost > feature is available only while the e-bus alternate > feed switch is in the NORMAL position . . . and only > while power is being applied to the starter contactor > via crew controlled push button. > > The DC/DC converter can be of any pedigree since > > (1) it's never active during normal ops (EMC issues > disappear) > > (2) functionality is pre-flight tested every flight > cycle. > > (3) It is not a safety of flight issue since it's > only active for tens of milliseconds during > cranking -AND- failure of the converter does > not disable any accessory neeed for comfortable > termination of flight. > > (4) Since it is active for perhaps a second each > flight cycle and average utilization of the > light aircraft is less than 100 fligh cycles > per year, the service life of these devices > should exceed lifetime of the airframe. > > If there is a 'downside' to this approach, I suppose > that it causes the crew to 'load' the ship's battery > for preflight ops such as ATIS and clearance collection. > > But recall that we're assuming that the ship's battery > will be sized and maintained to meet design goals. In > the normal world, cranking the engine takes perhaps 5% > of battery capacity. Preflight ops of electro-whizzies > should require no more than that. That energy will be > replaced in the first few minutes of flight. > > I humbly suggest that the technique cited above > will deal with 100% of CBOT issues at zero cost of > ownership beyond initial purchase and installation > of the system and zero impact on system reliability > and performance. It also encourages the owner to > conduct due diligence in the maintenance of the > ship's battery since there are NO standby batteries > tending to lull one into a false sense of system > reliability. > > Cogent arguments pro and con are most welcome. > > Bob . . . > I like it; I might try it out on my old RV-4 electrical system. It's a pretty simple, crude system, but the Matronics fuel flow meter reboots on startup. Only potential downside I can see is that some avionics systems may well draw a total of 5 or 6 amps. If battery voltage drops down in the 8-9 volt range, you could see an additional 8 or 10 amps of load on the start PB. There are some planes out there that have the start PB feeding a starter with built-in solenoid/contactor; in those cases, the PB may be pretty heavily loaded. I toyed with the idea of using one of those 'switchers' to replace the isolation diode if I'd used a dual battery system (instead of the dual alternator system chosen) on my electronic injected engine installation. Charlie --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 13 ____________________________________ Time: 07:26:47 PM PST US Subject: Re: AeroElectric-List: B lead circuit breaker From: Ron Burnett Art, Yes, the volt meter shows 14.2 to 14.3 range in flight, unless it spikes I g uess? Ron Burnett May you have the Lord's blessings today! Sent from my iPad > On Oct 8, 2018, at 8:51 PM, Art Zemon wrote: > > Ron, > > Do you have a voltmeter in the plane? I am guessing that the circuit break er is popping because the voltage is going too high. Maybe a voltage regulat or problem. > > -- Art Z. > >> On Mon, Oct 8, 2018 at 8:34 PM Ron Burnett wrote : net> >> >> I have a Plane Power Alternator on my RV-6A and lately with the Aero Flas h strobes on at some point the B lead CB will pop. It does reset. Today I flew a 2 leg cross country for 4 hours total, all with the strobes off afte r the popping event 2 minutes into the flight. How would I determine if thei r is a problem with the strobes that might cause this problem? > -- > https://CheerfulCurmudgeon.com/ > > "We do not see the world as it is. We see the world as we are." ________________________________ Message 14 ____________________________________ Time: 08:37:35 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: B lead circuit breaker At 08:18 PM 10/8/2018, you wrote: > >I have a Plane Power Alternator on my RV-6A and lately with the Aero >Flash strobes on at some point the B lead CB will pop. It does >reset. Today I flew a 2 leg cross country for 4 hours total, all >with the strobes off after the popping event 2 minutes into the >flight. How would I determine if their is a problem with the strobes >that might cause this problem? > >Thanks for any hints. > >Ron Burnett What size is your alternator. What size is your B-lead breaker. Bob . . . ________________________________ Message 15 ____________________________________ Time: 10:55:50 PM PST US Subject: AeroElectric-List: Re: A brown-out alternative? From: "Eric Page" nuckolls.bob(at)aeroelect wrote: > I mentioned a few days ago that I thought I had yet another solution to the perennial brown-out gremlin. > > [SNIP] > > Cogent arguments pro and con are most welcome. Clever idea, Bob -- I like it! As Charlie mentioned, the current drawn by the DC-DC boost converter could be significant, and would of course increase with decreasing supply voltage. There's also the likelihood of substantial inrush current at start-up. Unless an adequately beefy start switch is specified, its contacts might suffer from making and breaking this load. This problem might be mitigated by powering the DC-DC boost converter either from the load side of the starter contactor (in parallel with the starter) or via a cube-type automotive relay. This would also simplify adding this design as a retrofit, since the start switch wiring/CB/fuse would not have to be upgraded to carry the boost converter's supply current. A bit of eBay searching resulted in several potential candidates for the boost converter. These first two are quite small and conveniently packaged; they appear to be the same unit in different enclosures. Power output might be marginal and their 11V max input might be an issue: https://www.ebay.com/itm/323360110037 https://www.ebay.com/itm/123391340337 These two are significantly more powerful and have a wider input voltage range: https://www.ebay.com/itm/321795754199 https://www.ebay.com/itm/263796566855 If one didn't want to use an eBay boost converter of unknown quality, Digi-Key offers this unit, which is specified for high vibration and extreme temperatures in railroad use, but doesn't cost a fortune. However, its minimum input is 9V, which might not be low enough in some cases. https://www.digikey.com/short/jnnh51 Eric Read this topic online here: http://forums.matronics.com/viewtopic.php?p=483720#483720 ------------------------------------------------------------------------------------- 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.