---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 05/06/07: 17 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:33 AM - Lightspeed electronic ignition (frequent flyer) 2. 09:04 AM - Re: Lightspeed electronic ignition (Matt Prather) 3. 10:16 AM - Re: ring terminals (Bill McMullen) 4. 10:26 AM - Re: Two Txrs on one antenna (Robert L. Nuckolls, III) 5. 10:54 AM - Re: Z-13/20 Questions (Aaron Gleixner) 6. 11:36 AM - Wiring for HID lights (Dr. Andrew Elliott) 7. 12:39 PM - Re: Re: ring terminals (Kevin Horton) 8. 12:47 PM - Broken Battery (Charles Brame) 9. 02:14 PM - Anyone know this connector ? (Gilles Thesee) 10. 02:40 PM - Re: BASIC DUAL INDEPENDENT POWER SUPPLY (Peter Harris) 11. 05:50 PM - Trim switchs (JimT) 12. 06:47 PM - Re: Trim switchs (Richard E. Tasker) 13. 10:03 PM - Re: BASIC DUAL INDEPENDENT POWER SUPPLY (Robert L. Nuckolls, III) 14. 10:04 PM - Re: Broken Battery (Robert L. Nuckolls, III) 15. 10:06 PM - Re: BASIC DUAL INDEPENDENT POWER SUPPLY (Robert L. Nuckolls, III) 16. 10:09 PM - Re: Broken Battery (Robert L. Nuckolls, III) 17. 11:20 PM - Re: BASIC DUAL INDEPENDENT POWER SUPPLY (Peter Harris) ________________________________ Message 1 _____________________________________ Time: 08:33:15 AM PST US From: frequent flyer Subject: AeroElectric-List: Lightspeed electronic ignition I posted this request once before but didn't get any response. I have an original version of the Lightspeed ignition which was discontinued in 1995 but don't have the manual. I'm looking for a copy of it. I've downloaded the new manual off the website and sent the flywheel off to be drilled and requested the manual. They sent the new one for $20 but I still don't have all the info I need. Can anyone help me out with a copy? Thanks, Jack in AZ --------------------------------- Don't be flakey. Get Yahoo! Mail for Mobile and always stay connected to friends. ________________________________ Message 2 _____________________________________ Time: 09:04:31 AM PST US Subject: Re: AeroElectric-List: Lightspeed electronic ignition From: "Matt Prather" I thought I had posted this before. Please check out the following link: http://www.webpak.net/~mprather/Share/LSE_manual.pdf Matt- > I posted this request once before but didn't get any response. I have an > original version of the Lightspeed ignition which was discontinued in 1995 > but don't have the manual. I'm looking for a copy of it. I've downloaded > the new manual off the website and sent the flywheel off to be drilled and > requested the manual. They sent the new one for $20 but I still don't have > all the info I need. Can anyone help me out with a copy? > > Thanks, Jack in AZ > > > --------------------------------- > Don't be flakey. Get Yahoo! Mail for Mobile and > always stay connected to friends. ________________________________ Message 3 _____________________________________ Time: 10:16:11 AM PST US Subject: AeroElectric-List: Re: ring terminals From: "Bill McMullen" If you're ordering terminals from Aircraft Spruce, I'd recommend that you double check the AMP part numbers on them. Hard to believe, but quite a while ago I ordered some butt splices from them and received the cheap vinyl ones without the extra sleeve ... they immediately went into the garbage can. I also notice that some of their ring terminals use the word "vinyl" in the description. I can vouch that B&C, Terminal Town and others know what "real" PIDG Mil-Spec terminals are. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=111175#111175 ________________________________ Message 4 _____________________________________ Time: 10:26:46 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Two Txrs on one antenna At 02:13 PM 5/4/2007 -0400, you wrote: > >I've been following the discussion regarding running two transceivers on >one coax line......... some very enlightening opinions! >Wouldn't a 12vDC coaxial relay do the job? >See any local ham over forty for details...... A relay (or switch) is useful for the selective connection of two devices to a single device. In this case, one could have a single antenna and two transceivers, or two antennas and one transceiver. We do the later on an agile military trainer where under certain flight conditions, the airframe masks the ability of a single antenna to provide omnidirectional performance. But in either instance only ONE of the TWO switched devices gets the benefit of the single at any given time. For dual transceivers to share a common antenna such that both may listen and either may transmit requires a device referred to as a diplexer. See: http://en.wikipedia.org/wiki/Diplexer An alternative product would consist of a pair of relays combined with an distribution amplifier that takes a single antenna and drives two receivers but senses when PTT for any one transceiver is active and captures the antenna for the exclusive use of the active transmitter. The amplifier/switch can be less expensive than a diplexer but it adds complexity to the system and new failure modes. A malfunction in the amplifier/switch might not only cripple ability of both transceivers to talk, it might couple transmitter energy into the other transceiver's input and damage the receiver. After the pilot tries one transceiver and finds that it doesn't work he tries the other and finds that it doesn't work either . . . now both receivers are hosed as well. Anecdotally, consider this. I work in a factory that produces a lot of $high$ aircraft ranging from 1/2 to 15 million dollars. If any group of owner-operators perceived a lower cost of ownership for having installed either a passive device like a diplexer or an active device such as an amplifier/switch, for the purpose of eliminating one antenna, they would have asked for it and we would no doubt have provided it. The reason for TWO systems is redundancy. Bringing two transceivers into a single antenna has not passed muster with the reasoning of a whole lot of folks. Let's not spend too much time wishing for 0.25K more IAS by the elimination of one antenna traded for a demonstrated risk to loss of redundancy and possibility of unhappy failure modes. Bob . . . ________________________________ Message 5 _____________________________________ Time: 10:54:02 AM PST US From: Aaron Gleixner Subject: Re: AeroElectric-List: Z-13/20 Questions Bob, Thanks for the response. After having alternators fail on 3 of my last 4 cars at relatively low time, I'm working on the assumption that the main alternator will fail at some point. Considering Murphy's Law, I know it will happen in heavy IFR with the entire family on board. Also, with the EFIS, I won't have a vacuum system to keep me straight and level, when the alternator fails, unlike some of the older planes you mention below. The minimum equipment list I developed is as follows: Garmin 430W - Having a hard time finding exact power usage, but most people seem to be using 3 Amps for the Nav and 1 Amp for the Comm (+6A more when transmitting) Garmin 330 Transponder - 2A Digiflight Autopilot - 0.5 A Base load + 2 Amps intermittent for Servos Grand Rapids EFIS - 2A (Two Screens) + 0.2 A for AHRS Interior Lights + Bose Headsets - 0.4 A Electric Trim - 0.3A + 1.2A intermittent for servos Backup ADI - 0.5A This gives a continuous load of 9.9A going intermittently to 13.1A. This loading seems to be in excess of what you would like for the SD-8, and even reducing the EFIS to 1 screen still seems like too much. So this drove me to look at the SD-20. When looking at the differential from the SD-8 to SD-20, I am estimating a $250 price difference (OV regulator included) and 2 pound weight increase. With the ability of the SD-20 to carry all the loads, even during landing, having a healthy battery becomes less critical. With my battery at $150, being able to extend replacements by even 1 year, rapidly pays off the $250 alternator difference, to the point where the larger alternator could have the lower life cycle cost. For me the two pounds is insignificant, and my lower stress levels when the main alternator fails would be a significant plus for the SD-20. So this brings me back to the desire to have the optimal single battery, dual alternator setup using the SD-20. The Z-12 diagram comes close, but failure of the master contactor would really ruin my day especially without a well maintained battery. It also only allows for 7A or less on the endurance buss. Z-14 seems like overkill, with plenty of extra components to maintain, along with the second battery. Z-13/8 seems like the optimal setup, assuming I could upsize to the SD-20, and enlarge the endurance buss and alternate feed to handle 20 Amps. The Z-13/20 setup adds the 2nd contactor, which now causes lots of wire run problems with the battery in the tail. Bob, what am I missing? Do you see any issues with using the Z-13/8 setup and replacing the 7A fuse on the battery bus with a 20A fuse, upsizing the wire to handle 20A, getting an e-bus diode that can handle 20A, and picking an e-bus switch good for 20A. The SD-20 Alt Field would be run off the e-bus to assure it continues to run if the master contactor fails. Could this be the replacement diagram when you pull Z-13/20 from the book? I guarantee there are other RV-10 builders that are looking for the optimal 1 battery, 2 alternator solution that has the power to run an EFIS/autopilot/transponder/GNS430 or equivalent package when the primary alternator fails. Aaron "Robert L. Nuckolls, III" wrote: At 01:46 PM 4/29/2007 -0700, you wrote: >I'm planning the electrical system for my RV-10, and really like the >layout of the Z-13/8 system, but want the extra power of the SD-20. I >originally was looking at the Z-12 layout, but didn't like 1) Single point >failure of battery contactor leaves you running endurance bus on battery >only, and 2) in the event of main alternator failure, I want to quickly >switch to a large endurance bus and not have to start turning off loads >individually on the main bus if I'm over 20 Amps. > >My question is why can't I use the Z-13/8 layout, and simply increase the >size of the e-bus fuse on the main battery bus to 20 amps, and us an e-bus >alternate feed switch that could handle 20 maps. The alternator field for >the backup alternator could be run from the e-bus. It eliminates the >S701-1 e-bus contactor which adds a lot of wire runs for the RV-10 with >battery in the tail. Seems like a simple solution, what am I missing? Under what conditions to you expect to exploit the capability of so robust a standby system? And what is the probability of experiencing such an event? There are hundreds of thousand of airplanes flying wired per Figure 17-1. If I were to choose to venture into IMC with a rented airplane, what I see is what I get. It's all "certified" and and not one pilot I know has ever opined that he/she would never file to go into the clouds because the airplane offered weak, if any options for plan-b. The airplane might still be fitted with a flooded battery that only gets replaced when it fails to crank and engine. The alternator is a descendant of the best-we-knew- how-to-do in 1965 and are technological junk by today's standards. Given the proven track record of modern alternators, RG batteries, and preventative maintenance philosophies that insure minimal battery capacity, if you were still wired per C-172, your electrical system offers a quantum jump in reliability. Now comes an opportunity to add still more capability for avoiding a bad day with the wife and kids aboard. Converting the avionics bus to a dual feed endurance bus along with a load shedding plan that may well offer battery only endurance that exceeds duration of fuel aboard. Then we have the prevalence of all electric panel hardware that offers a rational way to get rid of the weight and complexity of a vacuum system that leaves a vacuum pump pad open. This is an opportunity to support an 8A endurance bus indefinitely and save 100% of a well maintained battery for approach and landing. You've said you "want" the extra power of the SD-20 . . . under what conditions would you expect to "need" that much endurance power? Finally, given the demonstrated performance of modern alternators, batteries and e-bus structures, what is the perceived return on investment for adding weight and complexity to a system that is pretty close to "golden". What you propose to do can be done. There are many variations on a theme that can be considered and installed in your project. My advice is to first deduce circumstances and put numbers to the situation that makes Z-13/8 fall short of your reliability needs. I.e, do the failure mode effects analysis. Recall that 99.99% of all breakers installed on all aircraft are never called upon to do their job but they take up space and offer no small cost-of-ownership. If there's something "missing" in your proposal for a more robust endurance supply, it's for not expressing numbers and logic that offer a compelling argument for doing so. There are a gazillion things all those buttons do on my VCR, TV and cable remotes that I would just as happy with if they were not there. I'm always hitting the wrong button in the dark. What you need to do is properly convince yourself that the proposed change is a good thing. At the moment, I can perceive no conditions of operation that make the SD-20 attractive, perhaps you have some ideas that have not been considered here on the List. But take care lest you're simply jacking up cost-of-ownership for your project by adding "breakers that never need to work" and "buttons that are a pain-in-the- arse in the dark." In fact, I've convinced myself that Z-13/20 architecture needs to come out of the next revision. The next step up from Z-13/8 should be Z-14 and I'd judge that very few, perhaps 1% of OBAM aircraft projects would make good use of a Z-14 installation. Is there a better place to invest the cash and fuel? Bob . . . ________________________________ Message 6 _____________________________________ Time: 11:36:07 AM PST US From: "Dr. Andrew Elliott" Subject: AeroElectric-List: Wiring for HID lights Gang: I am planning on HID lights for my plane. The specs say that they draw about 10 amps for starting and then 3.5 amps while running steady state. Must I choose the wire size for the short duration load or can I size for the long duration load, or maybe split the difference? The runs are long, since the lights are in the tips and the ballasts are only a foot or so inboard. The "stock" automotive installation comes with 15 amp in-line fuses. Andy Elliott, Mesa, AZ N601GE (reserved) 601XL/TD/QB, Corvair, building... ________________________________ Message 7 _____________________________________ Time: 12:39:47 PM PST US From: Kevin Horton Subject: Re: AeroElectric-List: Re: ring terminals On 6 May 2007, at 13:14, Bill McMullen wrote: > > > If you're ordering terminals from Aircraft Spruce, I'd recommend > that you double check the AMP part numbers on them. Hard to > believe, but quite a while ago I ordered some butt splices from > them and received the cheap vinyl ones without the extra sleeve ... > they immediately went into the garbage can. I also notice that > some of their ring terminals use the word "vinyl" in the > description. I can vouch that B&C, Terminal Town and others know > what "real" PIDG Mil-Spec terminals are. > Other people have reported ordering plumbing fittings with MS part numbers, and receiving fittings without any markings on them. The Mil-Spec requires that hardware be marked, so these fittings clearly did not meet the Mil-Spec. Anyone ordering stuff from ACS should inspect what they get very carefully to ensure they have not substituted a lower quality item. http://www.vansairforce.com/community/showthread.php?t=15575 I won't speculate as to whether these problems are due to poor quality control or fraud. Kevin Horton RV-8 (finishing kit) Ottawa, Canada http://www.kilohotel.com/rv8 ________________________________ Message 8 _____________________________________ Time: 12:47:00 PM PST US Subject: AeroElectric-List: Broken Battery From: Charles Brame PC-680: $84.29 from Batteries 4 Everything. Website: https://www.batteries4everything.com/index.html Click on Products, Scroll down and click on: Odyssey, Hawker, Cyclon, Genesis Batteries, Next page click on: Odyssey, Next page click on: PC680. I'm sure shipping to Australia is expensive, but shouldn't be outrageous. Outfit is very responsive and ships quickly in the States. For the record, my PC-680 is approaching 5 years old, still holds a 12.8 volt charge indefinitely, spins the engine quickly and returns to a full charge within moments of turning on the alternator. It sat on a bench with no charger for nearly a year and still had over 12 volts charge. I do keep a quality charger on it now for extended down times. Charlie Brame RV-6A N11CB San Antonio -------------------------------------------------- > Time: 01:53:38 AM PST US > From: "Chris Byrne" > Subject: AeroElectric-List: Broken Battery > > > I have an Odyssey PC680. Its 18 months old and has been in the A/C > as power > whilst fitting wiring and instruments. > > Now after a full charge all I see is about 12 Volts and placing a > load of 2 > or 3 amps on it sees the Voltage drop to about 9.5 V in about 10 > mins after > which the EFIS and radio start to fall over. > > It has been run completely flat on at least on occasion, maybe > twice. I am > using a quality charger designed for AGM batteries. The local > battery supply > shop has tested it and gets the same result. > > I now have a new one. > > Did running it flat stuff it? > Can it be bought back to life? > > By the way I paid $240.00 US for the new one, what are you guys in the > States paying. I think the importer is ripping us off over here. > > Chris Byrne > SYDNEY > > ________________________________ Message 9 _____________________________________ Time: 02:14:39 PM PST US From: Gilles Thesee Subject: AeroElectric-List: Anyone know this connector ? Hi all, Does anyone know where to source such a connector (brand, p/n), or the crimp contacts to repair it ? http://contrails.free.fr/instruments_connector.php It was part of a UMA oil pressure sensor cable, and suffered from heat under the cowling, so I would like to reconstruct a more robust cable to match the male sensor. Thanks in advance, Best regards, Gilles http://contrails.free.fr ________________________________ Message 10 ____________________________________ Time: 02:40:46 PM PST US From: "Peter Harris" Subject: RE: AeroElectric-List: BASIC DUAL INDEPENDENT POWER SUPPLY Ken, The idea of a second regulator feed I like better than a second battery, a very good idea I think. The PM alternator itself is likely to be very reliable long term. What protection would you use for the second feed? Is this a case for a transorb and a CB which can be reset on the panel? I am already using the diodes as shown switched NC with a green LED to show each side active. Now Z-25 solves the problem of running the alternator without the battery. Peter -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ken Sent: Thursday, 3 May 2007 10:15 PM Subject: Re: AeroElectric-List: BASIC DUAL INDEPENDENT POWER SUPPLY Peter Much as I hate attachments (slow dial up connection), I took a quick look and I really think you are kidding yourself about this. Look at all the things that can fail your alternator and it's wiring. I suspect that a modern sealed battery is an order of magnitude more reliable for its first couple of years of life. Even in the unlikely event that the battery did fail, it is unlikely to do so in a manner that will bring down your system. I suspect that your proposal adds no reliability to your electrical supply. A separate small battery would be there if it were my system and I was concerned about supply reliability. Yes I'd keep a fuselink, C/B, or fuse near the battery so that a short in the alternator or all that wiring doesn't draw a lot of current out of the battery. Now for the sake of discussion... If you really want to do this - what about considering a separate alternator feed right from the alternator that would include a second rectifier/regulator operating with or without a separate battery ;) Separate wiring and no excess connections such as loadmeters. The last time I bought a battery, there was a well dressed guy trying to talk the price down a bit on a flooded cell motorcycle battery. When I asked for a small AGM battery by part number, the salesman said "so nice to have a customer that understands value". Both batteries were interchangeble but mine was over twice the money and should last many times longer than the cheap one. Ken Peter Harris wrote: > Bob, > > I have been guilty of asking a lot of questions before reading your > files and thanks to Gilles, Ken and yourself for the advice and patience. > > Your files are a gold mine of good engineering design. > > My project is for conversion of a Quickie Q-200 with Jab 3300 single > phase PM alternator and a regulator like the SD-8 setup to make a safe > dual independent power supply ready for an EFI conversion. > > The original Quickie circuit has no relays and protection is by fuses > to each connection and the DPST master switch which isolates battery > from alternator from bus. > > Z-25 covers everything I think I need except for the dual independent > source for the ebus. > > For this I have copied a practice I have seen here in Oz which I > understand is approved by CASA as a dual independent power supply by > taking the centre tap from two diodes back to back and I have shown > the setup at the bottom of Z-25 following. I have also included an > over current module "A" which I had from another installation. (Gilles > has pointed out that either the fusible link or the OCM is redundant). > > The ebus feed that I have shown here is I think similar to what you > have done in Z-19 note 24. > > I want to keep the thing as simple as possible and have left the SPDT > master switch but would use a relay if you advise. > > I would welcome your advice on the merits of fusible links vs CB which > reset or can be reset, and whether you think the OCM is worth keeping, > or if you see something wrong with the diagram. > > Thanks > > Peter. > ________________________________ Message 11 ____________________________________ Time: 05:50:21 PM PST US Subject: AeroElectric-List: Trim switchs From: "JimT" Hello folks Just exploring an option. Awhile before I started lurking here I bought an EXP bus. yes , yes I know, I wouldn't buy it today, but it seemed a good idea at the time. so I am setting up the trim motor with controls on the pilots joystick and the throttle, so the right guy can acess trim if desired. The usual drill is a rely to avoid direct shorts when opposite conditions are set on the two switches. Shouldn't happen often, will happen. Problem is I don't know much ( anything?) about the characteristics of the PTC breakers in the EXP Bus. Do they trip fast enough to protect 20 ga wire? The manual states they will reset in 10-15 seconds after load removal , and can be tripped thousands of times without damage. Solid state devices usually are quite reliable when used within the stated limits. Would depending on the breaker be more reliable then the DPDT relay? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=111236#111236 ________________________________ Message 12 ____________________________________ Time: 06:47:53 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: Trim switchs The PTC breaker will switch almost instantly and will easily protect the 20 ga. wire - that is its whole purpose in life. The way a PTC works is that under normal operating conditions it is a very low resistance device. As long as the current through the device is kept below the trip current nothing happens (except current is allowed to flow). As soon as the current gets too high, the device starts to heat up. When it heats up its resistance increases. Of course, when the resistance increases, it heats up faster and the resistance goes up more. This all happens in milliseconds if you have a significant overload. The resistance goes up orders of magnitude which then limits the current to a few milliamps through even a short circuit. As long as the short is there, the high resistance creates enough heat to keep it at a high resistance. As soon as the short is removed, the PTC cools down and the resistance goes very low again, allowing normal currents to flow. However, I might use the DPDT relay anyway. For two reasons: One reason is that, while the PTC easily protects the wire, it may not do such a good job protecting the switch contacts. Depending on what switch you use, you might be overloading the contacts for too long. I suppose it depends on what switch you use and how many times you expect to have a direct short between the stick and throttle controls whether it is a problem or not. The second reason is: As long as this is the only device on that particular PTC you would probably be okay as noted above. However, if you are sharing the PTC with other devices, tripping it by shorting the switches would shut everything else on the protected circuit down. Unfortunately, the PTC will now no longer automatically reset when the short is removed - the other devices are still trying to draw current and will keep the PTC set! You will have to shut off all other loads on that particular PTC so it can reset and them turn them all back on. Dick Tasker JimT wrote: > >Hello folks > >Just exploring an option. Awhile before I started lurking here I bought an EXP bus. yes , yes I know, I wouldn't buy it today, but it seemed a good idea at the time. >so I am setting up the trim motor with controls on the pilots joystick and the throttle, so the right guy can acess trim if desired. The usual drill is a rely to avoid direct shorts when opposite conditions are set on the two switches. Shouldn't happen often, will happen. > >Problem is I don't know much ( anything?) about the characteristics of the PTC breakers in the EXP Bus. Do they trip fast enough to protect 20 ga wire? The manual states they will reset in 10-15 seconds after load removal , and can be tripped thousands of times without damage. Solid state devices usually are quite reliable when used within the stated limits. Would depending on the breaker be more reliable then the DPDT relay? > > >Read this topic online here: > >http://forums.matronics.com/viewtopic.php?p=111236#111236 > > > > -- Please Note: No trees were destroyed in the sending of this message. We do concede, however, that a significant number of electrons may have been temporarily inconvenienced. -- ________________________________ Message 13 ____________________________________ Time: 10:03:50 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: BASIC DUAL INDEPENDENT POWER SUPPLY At 07:13 AM 5/5/2007 +1000, you wrote: > > >Bob, >The EFI including pump, ECU and injectors together with his main bus radio >and instruments is using 4A according to advice from the guy who engineered >this simple single body TBI system. (I don't have a figure for the separate >ebus draw for the EFI so you would need to discount for radio and >instruments)I could also run the electronic ignition module and ignition >coil for additional ebus current I guessed 4A but it would probably be less. >I am using a Bosch HE coil. >Alternative landing sites are up to 1hr apart. The endurance is 41/2HRS. >Thanks >Peter So how much batter-only endurance are you designing for? What plans are you making for preventative maintenance to make sure that design goals slip for lack of due diligence in maintenance? Assuming you're considering a battery capacity on the order of the popular 3 x 6 x 7 inch form-factor, a 4A load on a new battery will give you just over two hours of operation assuming that nothing in your system gives up above 10.5 volts. See: http://www.aeroelectric.com/Pictures/Curves/17AH_Capcity_vs_Load.gif Here we see that a 17 ah battery will carry 4A for about 3 hours. http://www.aeroelectric.com/Pictures/Curves/28AH_12V_Capacity_vs_Load.gif To go out for duration of fuel aboard, you'll need to upsize to the 28 ah critter for an increase to something on the order of 360 minutes or 6 hours. It's my recommendation that you consider z21 posted at: http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z21A.pdf Stuff needed to keep the engine running should run from the battery bus and be switched by their own power switches SEPARATE from DC power management for the rest of the airplane. You don't need the diodes. A battery does not fail in a manner that takes the rest of the system down. Tying the alternator directly to the battery al-la Z13/8 lets you load-shed the main bus plus contactor and run only battery bus + ebus loads. Even the e-bus can be shed if desired. I presume you're planning on carrying flight-bag backups for the panel mounted hardware like http://www.aeroelectric.com/Pictures/Misc/Failure_Tolerance.pdf This architecture meets the design goals of dual supplies for keeping the engine lit up. Bob . . . ________________________________ Message 14 ____________________________________ Time: 10:04:11 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Broken Battery At 06:52 PM 5/5/2007 +1000, you wrote: > > >I have an Odyssey PC680. Its 18 months old and has been in the A/C as power >whilst fitting wiring and instruments. > >Now after a full charge all I see is about 12 Volts and placing a load of 2 >or 3 amps on it sees the Voltage drop to about 9.5 V in about 10 mins after >which the EFIS and radio start to fall over. > >It has been run completely flat on at least on occasion, maybe twice. I am >using a quality charger designed for AGM batteries. The local battery supply >shop has tested it and gets the same result. > >I now have a new one. > >Did running it flat stuff it? Probably . . . >Can it be bought back to life? Probably not. >By the way I paid $240.00 US for the new one, what are you guys in the >States paying. I think the importer is ripping us off over here. Try a locally marketed brand in the same form factor. I think you'll get a lower cost of ownership and better reliability with less expensive batteries replaced more often. By the way, the battery you just replaced probably wouldn't have cap-checked at any really useful energy storage level. Bob . . . ---------------------------------------- ( IF one aspires to be "world class", ) ( what ever you do must be exercised ) ( EVERY day . . . ) ( R. L. Nuckolls III ) ---------------------------------------- ________________________________ Message 15 ____________________________________ Time: 10:06:00 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: BASIC DUAL INDEPENDENT POWER SUPPLY At 11:46 AM 5/5/2007 +1000, you wrote: > > >Bob, >Just to clarify I do not propose to use Z-19 , only the two diodes dual feed >as shown in Z-19 and note 24. What I have in mind is to use Z-25 just as I >have shown it in my post ie Z-25 plus the double diode feed from Z-19 >Peter Never thought you were proposing Z-19. That effort was produced for other builders. You don't need the diodes. See my earlier post on this topic and the new figure Z-21 Bob . . . ________________________________ Message 16 ____________________________________ Time: 10:09:06 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Broken Battery At 02:45 PM 5/6/2007 -0500, you wrote: >PC-680: $84.29 from Batteries 4 Everything. > >Website: >https://www.batteries4everything.com/index.html > >Click on Products, Scroll down and click on: Odyssey, Hawker, Cyclon, >Genesis Batteries, Next page click on: Odyssey, Next page click on: PC680. > >I'm sure shipping to Australia is expensive, but shouldn't be outrageous. >Outfit is very responsive and ships quickly in the States. > >For the record, my PC-680 is approaching 5 years old, still holds a 12.8 >volt charge indefinitely, spins the engine quickly and returns to a full >charge within moments of turning on the alternator. It sat on a bench with >no charger for nearly a year and still had over 12 volts charge. I do keep >a quality charger on it now for extended down times. Do you depend on this battery as a backup to the alternator? If so, have you cap-checked it recently? Bob . . . ________________________________ Message 17 ____________________________________ Time: 11:20:26 PM PST US From: "Peter Harris" Subject: RE: AeroElectric-List: BASIC DUAL INDEPENDENT POWER SUPPLY Bob, thanks I see now that battery capacity design and maintenance will do the job the simplest way. Yes I do have a Magellan 315 and it is loaded with bush air strips as well as regular airports. I am not sure if I understand what the self excitation feature is contributing, do we need it here? Peter -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Monday, 7 May 2007 4:02 PM Subject: RE: AeroElectric-List: BASIC DUAL INDEPENDENT POWER SUPPLY At 07:13 AM 5/5/2007 +1000, you wrote: > > >Bob, >The EFI including pump, ECU and injectors together with his main bus radio >and instruments is using 4A according to advice from the guy who engineered >this simple single body TBI system. (I don't have a figure for the separate >ebus draw for the EFI so you would need to discount for radio and >instruments)I could also run the electronic ignition module and ignition >coil for additional ebus current I guessed 4A but it would probably be less. >I am using a Bosch HE coil. >Alternative landing sites are up to 1hr apart. The endurance is 41/2HRS. >Thanks >Peter So how much batter-only endurance are you designing for? What plans are you making for preventative maintenance to make sure that design goals slip for lack of due diligence in maintenance? Assuming you're considering a battery capacity on the order of the popular 3 x 6 x 7 inch form-factor, a 4A load on a new battery will give you just over two hours of operation assuming that nothing in your system gives up above 10.5 volts. See: http://www.aeroelectric.com/Pictures/Curves/17AH_Capcity_vs_Load.gif Here we see that a 17 ah battery will carry 4A for about 3 hours. http://www.aeroelectric.com/Pictures/Curves/28AH_12V_Capacity_vs_Load.gif To go out for duration of fuel aboard, you'll need to upsize to the 28 ah critter for an increase to something on the order of 360 minutes or 6 hours. It's my recommendation that you consider z21 posted at: http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z21A.pdf Stuff needed to keep the engine running should run from the battery bus and be switched by their own power switches SEPARATE from DC power management for the rest of the airplane. You don't need the diodes. A battery does not fail in a manner that takes the rest of the system down. Tying the alternator directly to the battery al-la Z13/8 lets you load-shed the main bus plus contactor and run only battery bus + ebus loads. Even the e-bus can be shed if desired. I presume you're planning on carrying flight-bag backups for the panel mounted hardware like http://www.aeroelectric.com/Pictures/Misc/Failure_Tolerance.pdf This architecture meets the design goals of dual supplies for keeping the engine lit up. 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