---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 02/23/06: 45 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:04 AM - Topic with a little difference (Kingsley Hurst) 2. 04:33 AM - Re: Topic with a little difference (Robert L. Nuckolls, III) 3. 06:05 AM - EFIS Info (Bob C.) 4. 06:05 AM - Thermocouple wire connections (Gary Casey) 5. 06:29 AM - Re: Transponder/ RS-232 (Brian Lloyd) 6. 06:47 AM - Re: Topic with a little difference (Brian Lloyd) 7. 06:49 AM - Re: Thermocouple wire connections (Brian Lloyd) 8. 06:55 AM - Re: Temperature compensation, UMA CHT (Robert L. Nuckolls, III) 9. 07:12 AM - Re: Strange alternator behavior at Startup (Robert L. Nuckolls, III) 10. 07:17 AM - Re: Thermocouple wire connections (Robert L. Nuckolls, III) 11. 07:26 AM - Re: Re: Z-14 FADEC Version Question (Robert L. Nuckolls, III) 12. 07:34 AM - Re: Z-14 FADEC Version Question with P.S. (Robert L. Nuckolls, III) 13. 07:41 AM - Re: Topic with a little difference (Robert L. Nuckolls, III) 14. 07:42 AM - Re: Strange alternator behavior at Startup (Robert L. Nuckolls, III) 15. 08:14 AM - Re: SD8 Alternator Install - Z-12 vs. Manual (Robert L. Nuckolls, III) 16. 08:14 AM - Re: fluid level sensor needed (Robert L. Nuckolls, III) 17. 08:21 AM - Re: Z13-8 how to energize standby contactor? (Robert L. Nuckolls, III) 18. 08:21 AM - Re: Transponder/ RS-232 (Pat Hatch) 19. 08:29 AM - Re: Strange alternator behavior at Startup (Stewart, Michael (ISS Atlanta)) 20. 08:35 AM - Re: Odyssey % of charge (Correction) (Robert L. Nuckolls, III) 21. 08:40 AM - Re: ANL Current Limiter more than 6 inches from starter contactor (Robert L. Nuckolls, III) 22. 08:44 AM - Re: Strange alternator behavior at Startup (Robert L. Nuckolls, III) 23. 09:15 AM - Re: Strange alternator behavior at Startup (Stewart, Michael (ISS Atlanta)) 24. 09:21 AM - Re: Z-14 Question (Robert L. Nuckolls, III) 25. 09:44 AM - Re: Grab-bar FW penetration (John Burnaby) 26. 10:23 AM - Re: EFIS Info (D Wysong) 27. 10:23 AM - Re: Strange alternator behavior at Startup (Robert L. Nuckolls, III) 28. 10:48 AM - Re: EFIS Info (Pat Hatch) 29. 11:00 AM - Handy Battery Cpacity Calculator (was: Odyssey % of charge) (Bill Dube) 30. 11:26 AM - Re: EFIS Info (D Wysong) 31. 12:05 PM - Re: EFIS Info (Ed Anderson) 32. 12:10 PM - Re: Strange alternator behavior at Startup () 33. 12:11 PM - Re: Strange alternator behavior at Startup (Stewart, Michael (ISS Atlanta)) 34. 12:26 PM - Re: Topic with a little difference (Kingsley Hurst) 35. 12:26 PM - Avionics ground bus kit (Mickey Coggins) 36. 12:38 PM - Re: Re: Strange alternator behavior at Startup (Stewart, Michael (ISS Atlanta)) 37. 12:40 PM - Re: Re: Strange alternator behavior at Startup (Mickey Coggins) 38. 01:29 PM - Re: Re: Strange alternator behavior at Startup (Dave Morris \) 39. 01:46 PM - Re: Topic with a little difference () 40. 02:03 PM - Re: Re: Strange alternator behavior at Startup (Matt Prather) 41. 02:03 PM - Re: Re: Strange alternator behavior at Startup (Matt Prather) 42. 02:06 PM - Re: Re: Strange alternator behavior at Startup (Matt Prather) 43. 02:52 PM - Re: Avionics ground bus kit (Robert L. Nuckolls, III) 44. 03:08 PM - Re: Strange alternator behavior at Startup (Jon Goguen) 45. 11:18 PM - What happens if OV trips? (Scott) ________________________________ Message 1 _____________________________________ Time: 12:04:40 AM PST US From: "Kingsley Hurst" Subject: AeroElectric-List: Topic with a little difference --> AeroElectric-List message posted by: "Kingsley Hurst" All, We discussed a topic at work today which has baffled me for some time. Ok, I admit it is not hard to baffle me but I don't know the answer and I'm sure someone on this list will know so . . . . . I'm told that when welding on a vehicle that has an alternator, the diodes in the alternator can be damaged if the battery is not disconnected first. Fact or fiction ? If fact, explanations gratefully received thank you. Cheers Kingsley Europa builder in Oz. ________________________________ Message 2 _____________________________________ Time: 04:33:46 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Topic with a little difference --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 06:01 PM 2/23/2006 +1000, you wrote: >--> AeroElectric-List message posted by: "Kingsley Hurst" > > >All, > >We discussed a topic at work today which has baffled me for some time. >Ok, I admit it is not hard to baffle me but I don't know the answer and >I'm sure someone on this list will know so . . . . . > >I'm told that when welding on a vehicle that has an alternator, the >diodes in the alternator can be damaged if the battery is not >disconnected first. Fact or fiction ? > >If fact, explanations gratefully received thank you. Actually, the battery is the best filter in the vehicle for transients induced by an external source. This idea is further discredited by the notion that most system have multiple accessories that are less robust than the system's alternator. If the threat were serious, perhaps one would do well to remove all the fuses from the fuse block, disconnect all potentially vulnerable devices from the system, etc. etc. I can deduce no physics by which serious stresses might be induced into any of the system's components by welding equipment. Bob . . . < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ________________________________ Message 3 _____________________________________ Time: 06:05:50 AM PST US From: "Bob C. " Subject: AeroElectric-List: EFIS Info --> AeroElectric-List message posted by: "Bob C. " Now THIS is interesting! Press Release: Direct-To Avionics (RECALL ON ALL CROSSBOW 425EX AHRS) ...from Jeff Berlin (Publicity, D2Av) For Immediate Release Press Contact: Jeff Berlin 646.528.9696 Jeff@d2av.com DIRECT-TO AVIONICS ISSUES RECALL ON ALL CROSSBOW 425EX AHRS Bend, OR, February 21, 2006 Direct-To Avionics announced today a full recall of the Crossbow 425EX AHRS. Unresolved problems with Crossbow 420 Series AHRS preclude Direct-To Avionics (D2A) from incorporating Crossbow in future experimental Chelton Electronic Flight Instrumentation Systems (EFIS). "Direct-To Avionics is committed to providing the best, most reliable, and most accurate components for our Chelton EFIS systems. Our customers want to know that when they're flying with their families, they're flying with the highest quality, best performing equipment available," said Kirk Hammersmith, President of Direct-To Avionics. "Therefore, in our ongoing commitment to bring our customers the best in state-of-the-art EFIS systems, Direct-To Avionics will now supply the Pinpoint Inertial Inc. GADAHRS with our experimental Chelton EFIS systems." In side by side comparisons with certified systems by Rockwell Collins, Litef, and others, and after exhaustive, real-world flight testing, the Pinpoint Inertial GADAHRS (GPS / Air Data / Attitude and Heading Reference System) has proven to exceed all performance and reliability parameters established by D2A. Based on technology currently used in certified commercial and military applications, the Pinpoint Inertial unit is the first and only GADAHRS optimized for reliability while working within the dynamics of high-performance experimental aircraft. The shift to the Pinpoint Inertial system has been precipitated by performance and reliability problems plaguing the Crossbow 425EX. Copyright (c) 2006 Direct To Avionics Inc. All rights reserved. Specifications subject to change without notice. Direct-To Avionics requests that all Crossbow units be removed or henceforth limited to Day/VFR flight conditions until a control group has logged 100 hours each without any performance problems. For details regarding replacement of Crossbow units, please visit the Direct-To Avionics website at www.d2av.com. Direct-to-Avionics is the exclusive distributor of Chelton's experimental EFIS line. D2A also participates in the development and evaluation of future Chelton systems for both certified and experimental aircraft. Direct-to-Avionics is the preeminent source for the most reliable and affordable EFIS for experimental aircraft. ________________________________ Message 4 _____________________________________ Time: 06:05:50 AM PST US From: Gary Casey Subject: AeroElectric-List: Thermocouple wire connections --> AeroElectric-List message posted by: Gary Casey Now I'm second-guessing myself. I wired my thermocouples by connecting them to copper wire (twisted pairs) in the engine compartment. The firewall connections were prewired by my panel supplier to bulkhead connections with gold-plated terminals. I'm sure they used copper wires on the back side of the firewall. I'm trying to convince myself that the cold junction compensation is still good, but I'm worried that the transition to copper, being inside the engine compartment, effectively places the cold junction there and therefore I'll get an error in reading equal to the temperature difference between the engine compartment and the instrument on the panel. I'm tempted to pull all the wires and replace them with thermocouple wires that will penetrate the firewall and go directly to the instrument. That's a LOT of work , especially this late in the project. Tell me I don't have to do that. Gary Casey ________________________________ Message 5 _____________________________________ Time: 06:29:24 AM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Transponder/ RS-232 --> AeroElectric-List message posted by: Brian Lloyd DEAN PSIROPOULOS wrote: > --> AeroElectric-List message posted by: "DEAN PSIROPOULOS" > > Question on the Gray Code connection to the transponder. I have an Apollo > (UPS AT-now Garmin) SL70 transponder and it has a "D4" Gray code input. I > plan to use a Dynon EFIS D10 (not a D10-A) as my encoder but it does not > have a "D4" Gray code output. What should I do with this connection at the > Transponder end? Can I just leave it floating, do I need to ground it or > what? Don't see anything in the manual about this. The Apollo stuff uses a serial code to communicate altitude information to their radios (GPS, etc.). I don't remember if the SL-70 accepts serial data in instead of gray code. I *think* it does but I am not sure. If it does not you will need a serial-to-grey-code converter to get the data from the Dynon to the SL-70. (I like the SL-70. I have had one in three airplanes at this point.) > I also plan to connect my full UPS AT radio stack together at their > respective RS-232 Tx/Rx I/O interfaces. My GPS/COM manual says to use a > three conductor shielded cable for two way RS-232 communication (Tx and RX) > and two conductor shielded for one way communication (Tx only or Rx only). > What is confusing to me though is their wiring diagram, it shows two wires > PLUS a shield connection to the transponder (one way comm). One wire is > connected to RS-232 Rx, another wire to a specific ground pin at the > connector AND....a shield connection to the mounting frame of the GPS/COM. > First, I'm a little confused about what UPS AT is saying...since the > Transponder will only require one way communication then according to the > text, I only need a TWO conductor shielded cable! But from the wiring > diagram, it looks like I need two conductors PLUS A SHIELD!!! They are using one of the wires in the bundle as the common and they are using the shield separately as just a shield. This is the best way to prevent ground loops and other noise pick-up. (The special ground for mic input is isolated from the chassis.) I recommend you use the approach shown in the wiring diagram with both the shield AND the wire common/ground. It will greatly reduce the chance you might have a noise problem on your mic. > Does that mean I need something like a shielded twisted pair for this > connection, or triax....or what? Yes. In that case you will need two-conductor shielded (two center conductors plus shield). If you have more signal lines you will need one extra for common. BTW, this is needed for mic and possibly for RS-232. It will not be needed for headphone wiring. (In fact, you probably do not need even shielded wire for headphone except in very rare cases.) -- Brian Lloyd 361 Catterline Way brian-yak at lloyd dot com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . - Antoine de Saint-Exupery ________________________________ Message 6 _____________________________________ Time: 06:47:16 AM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Topic with a little difference --> AeroElectric-List message posted by: Brian Lloyd Kingsley Hurst wrote: > I'm told that when welding on a vehicle that has an alternator, the > diodes in the alternator can be damaged if the battery is not > disconnected first. Fact or fiction ? > > If fact, explanations gratefully received thank you. I see Bob has replied and I think that he is right in general but I can tell you what the rationale is about disconnecting the alternator. Arc welding uses relatively high voltage (compared to your DC system) and potentially high amperage (once the arc starts, voltage goes down but current goes way up). Imagine you connect the ground from the arc welder to one of the two pieces of metal to be welded. When you go to strike the arc you may touch the other piece of metal before you get the arc started. This impresses a rather large voltage between the two pieces of metal. (This assumes that they are not clamped together well or that there is something else, e.g. paint, preventing good contact between the pieces of metal.) Now imagine that the case of the alternator is somehow connected to the first piece of metal and the ground of the battery is connected to the other. (We are postulating a cracked frame in your car or some such.) Now what you have done is to put the output of the welder in series with the battery going to the alternator. Since the welder may be putting out 80V-100V open-circuit, this is more than enough to cause the diodes in the alternator to go into reverse breakdown. The battery and welder then can deliver more than enough current to destroy the diodes. Could it happen? Yes. Is this likely to happen? No. Is it something you need to worry about? Probably not. But the point is good: that arc welder can put out a LOT of voltage before the arc actually starts. And if your bonding fails, the other wiring in your airplane or car can become the return for the current in the arc welder. It is probably better safe than sorry to disconnect or remove things when arc welding on your airplane. -- Brian Lloyd 361 Catterline Way brian-yak at lloyd dot com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . - Antoine de Saint-Exupery ________________________________ Message 7 _____________________________________ Time: 06:49:53 AM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Thermocouple wire connections --> AeroElectric-List message posted by: Brian Lloyd Gary Casey wrote: > instrument on the panel. I'm tempted to pull all the wires and > replace them with thermocouple wires that will penetrate the firewall > and go directly to the instrument. That's a LOT of work , especially > this late in the project. Tell me I don't have to do that. You don't have to do that. The errors will be small, especially if all your junctions that have similar metal pairs along the wire are at the same temperature. -- Brian Lloyd 361 Catterline Way brian-yak at lloyd dot com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . - Antoine de Saint-Exupery ________________________________ Message 8 _____________________________________ Time: 06:55:46 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Temperature compensation, UMA CHT --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 02:11 PM 2/22/2006 -0600, you wrote: >--> AeroElectric-List message posted by: AI Nut > >Ok, maybe I'm being dense here, but here goes: >If the 594 is used, no further cold junction compensation is necessary >from the TC side is necessary. If the UMA instrument needs it, then I >suggest dropping it. Use a simple microprocessor (about $1) and an LED >display ($40?) instead. Some of the micros have an LED display driver >already built-in, IIRC. Check out Freescale's website. I don't think the UMA bothers to use dynamic cold-junction compensation. Their cold junction is at the back of the instrument and the calibration is optimized at a 20C cockpit. So ranges of temperatures that most pilots are willing to endure in the cockpit is assumed to introduce insignificant error. Possibly true for most enclosed cockpit/pilot combinations. This is an open cockpit a/c where the owner says his motivations to fly outweigh other pilot's inhibitions (maybe he has a heated flight-suit). In any case, the stated accuracy of the stock gage is found deficient for his needs. The idea is to apply EXTERNAL signal conditioning using the 594 and drive the instrument with whatever combination of constant current/voltage seems best. This allows us to provide offset/scale-factor pots that will permit calibration to number probably better than the off-the-shelf instrument. Dynamic cold-junction compensation comes with the package. >If he's married to the UMA, then enjoy the exercises 8-). That's the major rub. He has the instruments, they're both physically attractive for their size (tiny panel) and round dials but a tad short on performance. Just ONE of life's little challenges . . . Bob . . . ________________________________ Message 9 _____________________________________ Time: 07:12:58 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Strange alternator behavior at Startup --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 01:26 PM 2/22/2006 -0500, you wrote: >--> AeroElectric-List message posted by: Jon Goguen > >These modern IR regulators are are "intelligent", the IQ depending on >the particular model. LIke me, some need to warm up before it they >think well enough to work. Many have a ramp function to bring the >output current up slowly at low rpm to prevent sudden engine loading >when alternator torque would be high, so the slow ramp up of the output >isn't surprising. 35 degrees seems pretty warm to be seeing such a >long warm-up delay, and it's possible that the regulator IC is >defective for low temp operation. If you can trace the problem >directly to the regulator, say by warming it with a hair dryer before >starting on a cold day, you might consider replacing it, perhaps with >an external one that doesn't try to be quite so clever. Another >possibility is that the belt slips in the cold when it's a little bit >stiff, and the the alternator rpm drops below the minimum at which the >regulator will turn on the output. Many regulators keep the output off >below a minimum rpm, to prevent loading the engine during startup. You >might not be getting above this threshold until the belt warms up and >grabs better. Can you point us to any published literature on this? Please understand that I'm not attacking your assertions with any kind of "PROVE IT" attitude. My request is driven by the simple fact that many of my suggestions about the IR alternator have been driven by what I KNOW about them (admittedly not much . . . the automotive guys are not used to getting requests for such data . . . their gazillions of automotive customers don't care). A handful of idiots that want to put "automotive" stuff into airplanes are not to be taken seriously. When I've crafted architectures and design philosophies that assume NOTHING, I've had to field a barrage of cabbages and tomatoes from congregations of certain beliefs because I don't embrace their faith . . . when at the same time, the bibles upon which their faith is based appear not to be in print. My time to research such things is limited so I you (or anyone else on the list) can point me to any descriptive literature for any of the modern (or not so modern) products, I'd be grateful. Bob . . . ________________________________ Message 10 ____________________________________ Time: 07:17:27 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Thermocouple wire connections --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 06:03 AM 2/23/2006 -0800, you wrote: >--> AeroElectric-List message posted by: Gary Casey > >Now I'm second-guessing myself. I wired my thermocouples by >connecting them to copper wire (twisted pairs) in the engine >compartment. The firewall connections were prewired by my panel >supplier to bulkhead connections with gold-plated terminals. I'm >sure they used copper wires on the back side of the firewall. I'm >trying to convince myself that the cold junction compensation is >still good, but I'm worried that the transition to copper, being >inside the engine compartment, effectively places the cold junction >there and therefore I'll get an error in reading equal to the >temperature difference between the engine compartment and the >instrument on the panel. I'm tempted to pull all the wires and >replace them with thermocouple wires that will penetrate the firewall >and go directly to the instrument. That's a LOT of work , especially >this late in the project. Tell me I don't have to do that. What instruments? Do they feature dynamic cold junction compensation or static compensation. In either case, you're correct that splicing to copper wire at any location OTHER than proximity to where DYNAMIC cold junction compensation takes place, calibration of the instrument is a flag waving in the breeze. If it's static cold junction compensation (a la UMA) then you've got two flags waving in the breeze. I'm mystified as to why someone would take the time, effort and expense to PACKAGE such a device (the hard part) and then drop all their cookies on the floor by not putting $5 dynamic cold junction compensation in and educating their customers on the best we know how to do with thermocouples. Thermocouple temperature measurement technology goes back 100+ years when measuring the microvolt shifts in output was damned difficult. Now we can do it for peanuts and it seems to have been blown off by some purveyors of technology. Bob . . . < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ________________________________ Message 11 ____________________________________ Time: 07:26:04 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Z-14 FADEC Version Question --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:31 AM 2/22/2006 -0800, you wrote: >--> AeroElectric-List message posted by: "dannylsmith" > > > >nuckollsr(at)cox.net wrote: > > At 11:13 AM 2/21/2006 -0800, you wrote: > > > > > > > > > > > > > > > > Sorry I didn't give you enough info Bob. > > > > > > It's a Mattituck IOF-360 with B&C starter and 60A alternator - no vacumn > > > or mechanical gyros. It's all electric - all glass panel. It will be IFR > > > with Garmin GMA-340 Audio Panel, GNS-480 GPS/Nav/Com, GTX-330 Xpondr > > > (Traffic), SL-40 Com, TruTrak DigiFlight II VSGS, TruTrak ADI, GRT 4000 > > > EIS and two Horizon I EFISs with XM Weather. Much of this equipment > will > > > accept power from two sources. My backup to the Garmin equipment is the > > > TruTrak ADI and the EIS 4000 option of AS and Altitude. Plus the TruTrak > > > auto pilot. > > > > > > My plan is to use the Figure Z-14 FADEC and eliminate the aux alternator > > > and regulator. > > > > > > > > > > Then what you REALLY need is Z13/8 with a second battery. > > > > You have me confused Bob. I have a FADEC so why would I use the Z-13/8 > - all electric airplane on a budget with P-Mags instead of the Z-14 > FADEC? I just felt that with a FADEC engine with two PC-680s that I don't > need a second alternator. Your confusing the Z-figures as illustrations of ARCHITECTURE with recommended combinations of hardware to end up in the finished design. You don't HAVE to put p-mags in for Figure Z-13/8. Figure Z-19 suggests an architecture for an electrically dependent engine having one alternator and two batteries. But again, don't focus on individual equipment items illustrated but the plan-a/plan-b operational aspects offered by the architecture. Figure Z-14 with a cross-feed contactor is an architecture for totally isolated, independent, dual electrical systems. Since you plan only one alternator, Z-14 is not applicable. In simplest terms, Z-19 is an expanded version of Z-11 with a second battery added along with features to manage control and monitoring philosophies that you may find attractive. I suggested Z-13/8 because you'll have a vacuum pump pad with a cover plate over it. It seems a small cost and weight penalty to take advantage of that pad with a 4# alternator installation. But Z-11 with dual batts, or Z-19 is closer to what you're looking for. You can always add the /8 feature to either system at a later date. Bob . . . ________________________________ Message 12 ____________________________________ Time: 07:34:19 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Z-14 FADEC Version Question with P.S. --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:31 AM 2/22/2006 -0800, you wrote: >--> AeroElectric-List message posted by: "dannylsmith" > > > >nuckollsr(at)cox.net wrote: > > At 11:13 AM 2/21/2006 -0800, you wrote: > > > > > > > > > > > > > > > > Sorry I didn't give you enough info Bob. > > > > > > It's a Mattituck IOF-360 with B&C starter and 60A alternator - no vacumn > > > or mechanical gyros. It's all electric - all glass panel. It will be IFR > > > with Garmin GMA-340 Audio Panel, GNS-480 GPS/Nav/Com, GTX-330 Xpondr > > > (Traffic), SL-40 Com, TruTrak DigiFlight II VSGS, TruTrak ADI, GRT 4000 > > > EIS and two Horizon I EFISs with XM Weather. Much of this equipment > will > > > accept power from two sources. My backup to the Garmin equipment is the > > > TruTrak ADI and the EIS 4000 option of AS and Altitude. Plus the TruTrak > > > auto pilot. > > > > > > My plan is to use the Figure Z-14 FADEC and eliminate the aux alternator > > > and regulator. > > > > > > > > > > Then what you REALLY need is Z13/8 with a second battery. > > > > You have me confused Bob. I have a FADEC so why would I use the Z-13/8 > - all electric airplane on a budget with P-Mags instead of the Z-14 > FADEC? I just felt that with a FADEC engine with two PC-680s that I don't > need a second alternator. Your confusing the Z-figures as illustrations of ARCHITECTURE with recommended combinations of hardware to end up in the finished design. You don't HAVE to put p-mags in for Figure Z-13/8. Figure Z-19 suggests an architecture for an electrically dependent engine having one alternator and two batteries. But again, don't focus on individual equipment items illustrated but the plan-a/plan-b operational aspects offered by the architecture. Figure Z-14 with a cross-feed contactor is an architecture for totally isolated, independent, dual electrical systems. Since you plan only one alternator, Z-14 is not applicable. In simplest terms, Z-19 is an expanded version of Z-11 with a second battery added along with features to manage control and monitoring philosophies that you may find attractive. I suggested Z-13/8 because you'll have a vacuum pump pad with a cover plate over it. It seems a small cost and weight penalty to take advantage of that pad with a 4# alternator installation. But Z-11 with dual batts, or Z-19 is closer to what you're looking for. You can always add the /8 feature to either system at a later date. Bob . . . P.S. please note that the FADEC version of Z-14 simply eliminates the automatic paralleling of batteries for cranking so that the second battery can be held in isolated reserve to support FADEC systems not designed to live in the real world. Many designers of the new electronic support systems for engines have put some aspects of DO-160 in the "too hard" pile and choose not to live with starter current brown-outs . . . (See http://www.aeroelectric.com/Pictures/Curves/99_Saturn_SL1.jpg ) . . . common to every vehicle that cranks the engine from a battery. The result is that the system integrator (you) need to supply stand-alone power to keep you engine's electronics from wandering into the weeds during cranking. This is the prime driver for a second battery. Bob . . . ________________________________ Message 13 ____________________________________ Time: 07:41:42 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Topic with a little difference --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 06:45 AM 2/23/2006 -0800, you wrote: >--> AeroElectric-List message posted by: Brian Lloyd > >Kingsley Hurst wrote: > > > I'm told that when welding on a vehicle that has an alternator, the > > diodes in the alternator can be damaged if the battery is not > > disconnected first. Fact or fiction ? > > > > If fact, explanations gratefully received thank you. > >I see Bob has replied and I think that he is right in general but I can >tell you what the rationale is about disconnecting the alternator. > >Arc welding uses relatively high voltage (compared to your DC system) >and potentially high amperage (once the arc starts, voltage goes down >but current goes way up). Imagine you connect the ground from the arc >welder to one of the two pieces of metal to be welded. When you go to >strike the arc you may touch the other piece of metal before you get the >arc started. This impresses a rather large voltage between the two >pieces of metal. (This assumes that they are not clamped together well >or that there is something else, e.g. paint, preventing good contact >between the pieces of metal.) >Could it happen? Yes. Is this likely to happen? No. Is it something you >need to worry about? Probably not. But the point is good: that arc >welder can put out a LOT of voltage before the arc actually starts. And >if your bonding fails, the other wiring in your airplane or car can >become the return for the current in the arc welder. It is probably >better safe than sorry to disconnect or remove things when arc welding >on your airplane. Of course, this is a special case condition. I just worked a relay failure in an airplane where the failure caused a wire to become disconnected from the relay enclosure and drop down into other portions of the circuitry. The 115 vac 400 Hz power on this wire was conducted into other rather sensitive systems and caused a LOT of damage secondary to the relay's initial failure. I don't expect to see this again in my lifetime . . . especially after I keel-haul the relay guys for some really dumb design errors. The point to be made here is that if an alternator is at-risk for the secondary fallout of a failure (welder's inattention to proper grounding of his tool's electrical power) then components of the entire system are equally at risk. Protecting one's assets from this kind of event would call for disconnection of everything in the system, not just the alternator. Bob . . . ________________________________ Message 14 ____________________________________ Time: 07:42:29 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Strange alternator behavior at Startup --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:16 AM 2/22/2006 -0500, you wrote: >--> AeroElectric-List message posted by: "Stewart, Michael (ISS Atlanta)" > > >I have a 60amp internally regulated ND alternator with the alternator >contactor and crowbar protection on it. > >In cold weather, say below 35degreesF, on initial start, I have no >charge. If I let her sit for a few minutes at 800rpm and worm up a >little, then give her some rpm up above 1100rpm, voltage and amp charge >slowly come up to proper level. Takes about 4 seconds for it to come up. >If I don't raise the rmp and just let her idle at 800, then after about >10 minutes of warming up, the same behavior happens where the voltage >slowly comes up. I do not get this behavior when its above 40 degrees F, >nor do I get this behavior if it has been run already. > > >Killing the alt field wire will not kill the alternator once she is >making current. Which I believe is proper behavior with this alternator. If running this dog to ground involves swapping out the alternator, I'll offer core value and shipping to have the alternator for evaluation. Bob . . . < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ________________________________ Message 15 ____________________________________ Time: 08:14:15 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: SD8 Alternator Install - Z-12 vs. Manual --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 05:36 PM 2/19/2006 -0500, you wrote: >--> AeroElectric-List message posted by: "Steve & Denise" > > >I comparing the SD8 install manual to Z-12 and I'm a bit confused of why the >wiring difference. > >The install manual (Drawing 504-500 from B&C) details the following: > 1. Aux Alt field breaker connected to main power bus via 2A breaker >and aux alt switch then on to yellow OV crowbar module wire and onto 20 amp >relay. > 2. Install manual shows alt warning light coming off of relay > 3. Install manual shows a second power connection via 10A breaker to >main bus > > >Z-13 details > 1. Aux alt field connected breaker connected to 20Amp relay then onto >aux alt switch. Black wire of OV module is connected to relay. > 2. Z-13 does not show any aux alt warning light > 3. Z-13 shows 16Awg fuselink coming from Battery contactor > >There are more differences but can someone recommend which diagram to follow >and the reasoning for the differences. First, keep in mind that you're comparing two different architectures. You're trying to blend the difference between a pickup truck and a sedan. >When does the warning light come on for the aux alt? Some instructions say >the alt light comes on when the aux alt switch is off or it is OV. > >I plan on leaving the aux alt switch off all the time. Some have >recommended to leave it on but in this scenario how does one diagnose a >failed main alt if the backup alt has the ability to absorb all of the load? > >I'm also running a B&C 60 Amp alt with LR3 reg. > >Thanks for some clarification, Start with tossing out the B&C papers that show you how to wire up the SD-8 as the only power generating source for an airplane. Figure Z-13/8 does not have a warning light for the SD-8 because it's the standby alternator and you don't want a warning light starring you in the face for 99.9% of your flight where the SD-8 is never used. Yes, the SD-8 is left off all times the 60A machine is running. The LV warning in the LR-3 is to tell you when you need the SD-8. Under max endurance operations SD-8 only, there are no warnings . . . you already KNOW that your operating with limited capabilities so you'll have to watch a voltmeter -OR- install LV warning on the e-bus but this would be a bit of over kill. Bob . . . ________________________________ Message 16 ____________________________________ Time: 08:14:15 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: fluid level sensor needed --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:57 PM 2/19/2006 +0100, you wrote: >--> AeroElectric-List message posted by: Mickey Coggins > > > > I'm working on a one wire, no moving parts, thermally > > sensed low liquid level detection system that will be > > simpler to install and still more rugged but no schedule > > on that activity yet. If you need something tomorrow, > > consider the technology cited above. > >That sounds like a winner. Please keep us posted. > > > Some of these mount right through the sidewall of a > > container. You could install more than one and use > > simple indicator lamps to annunciate switch position. > >Looks like I need to modify the expansion tank drawing >I sent to Canton Racing to add a couple of 1/4" NPTs >onto the side. If that's for my product, it will use straight-threaded o-ring sealed fittings. Not sure what size yet . . . Bob . . . ________________________________ Message 17 ____________________________________ Time: 08:21:31 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Z13-8 how to energize standby contactor? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 03:46 PM 2/14/2006 -0800, you wrote: >--> AeroElectric-List message posted by: "Scott" > >I'm rebuilding the electrical system on my flying RV6a. Conventional Mags >but all electric panel, so leaning strongly toward the Z-13/8 configuration. >I have developed several questions, but I'll send them individually to try >to keep the list archive most useable. > >On the A13-8 diagram, it shows the Aux Alt "master" contractor energized >from the main battery side. Is there any reason not to energize it from the >SD-8 alternator side? My assumption is that the SD-8 will always generate a >voltage since it's got permanent magnets so it wouldn't need the battery to >energize the field before it was able to kick it's own relay on. It should >be a fine point that wouldn't usually matter, but if somehow the main >battery went flat (I don't know, flying with the Nav lights on durring the >day and not noticing a failed main alt because the low volts light bulb was >burned out?) it seems like it'd be nice to be able to bootstrap the system >from the SD-8. Last I heard, the SD-8 still needs a battery to come on line. If you want something better, hammer on B&C about this. There's no good reason for this not to be a feature of the SD-8. Z-13 is a two layer system that will function in the bare minimum SD-8/Single battery system common to hundreds of Long and VariEz aircraft flying the SD-8. Closing the battery master adds a second layer with a main-bus. Even if the SD-8 came up without a battery, hooking as shown is recommended . . . let it bring the battery up a bit and it will then close the battery contactor. You don't want to close the battery contactor under SD-8 only ops until you have airport in sight and your asking whatever is left in the battery + SD-8 support to let you run more goodies in the approach to landing phase. Bob . . . < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ________________________________ Message 18 ____________________________________ Time: 08:21:32 AM PST US From: "Pat Hatch" Subject: RE: AeroElectric-List: Transponder/ RS-232 --> AeroElectric-List message posted by: "Pat Hatch" Brian, you are correct, the SL70 can input either serial or gray code. The selection is made on the setup function during the post installation checkout. Pat --> AeroElectric-List message posted by: Brian Lloyd DEAN PSIROPOULOS wrote: > --> AeroElectric-List message posted by: "DEAN PSIROPOULOS" > > Question on the Gray Code connection to the transponder. I have an Apollo > (UPS AT-now Garmin) SL70 transponder and it has a "D4" Gray code input. I > plan to use a Dynon EFIS D10 (not a D10-A) as my encoder but it does not > have a "D4" Gray code output. What should I do with this connection at the > Transponder end? Can I just leave it floating, do I need to ground it or > what? Don't see anything in the manual about this. The Apollo stuff uses a serial code to communicate altitude information to their radios (GPS, etc.). I don't remember if the SL-70 accepts serial data in instead of gray code. I *think* it does but I am not sure. If it does not you will need a serial-to-grey-code converter to get the data from the Dynon to the SL-70. (I like the SL-70. I have had one in three airplanes at this point.) ________________________________ Message 19 ____________________________________ Time: 08:29:24 AM PST US Subject: RE: AeroElectric-List: Strange alternator behavior at Startup From: "Stewart, Michael (ISS Atlanta)" --> AeroElectric-List message posted by: "Stewart, Michael (ISS Atlanta)" Thanks Bob, Is the behavior of the alt continuing to charge after the field wire is killed, normal behavior? Means I have no way to stop the alternator once its alive, except for the crowbar protection on the alternator contactor, which I have not verified actually works. I don't have a way to kill it in a car driving down the road so I guess this should not bother me, somehow it does. Mike Do not archive -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Thursday, February 23, 2006 10:42 AM Subject: Re: AeroElectric-List: Strange alternator behavior at Startup --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:16 AM 2/22/2006 -0500, you wrote: >--> AeroElectric-List message posted by: "Stewart, Michael (ISS Atlanta)" > > >I have a 60amp internally regulated ND alternator with the alternator >contactor and crowbar protection on it. > >In cold weather, say below 35degreesF, on initial start, I have no >charge. If I let her sit for a few minutes at 800rpm and worm up a >little, then give her some rpm up above 1100rpm, voltage and amp charge >slowly come up to proper level. Takes about 4 seconds for it to come up. >If I don't raise the rmp and just let her idle at 800, then after about >10 minutes of warming up, the same behavior happens where the voltage >slowly comes up. I do not get this behavior when its above 40 degrees F, >nor do I get this behavior if it has been run already. > > >Killing the alt field wire will not kill the alternator once she is >making current. Which I believe is proper behavior with this alternator. If running this dog to ground involves swapping out the alternator, I'll offer core value and shipping to have the alternator for evaluation. Bob . . . < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ________________________________ Message 20 ____________________________________ Time: 08:35:18 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Odyssey % of charge (Correction) --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" I stubbed my toe in interpretation of the graphs in an earlier post. The revision is below: At 08:22 AM 2/14/2006 +0000, you wrote: >--> AeroElectric-List message posted by: > >If the charging system is not working does anyone have an approximate % of >remaining capacity versus voltage for a Odyssey PC680 or similar? > >What is a safe lower voltage limit one can discharge a PC680 to and not >cause permanent battery damage? Know that ALL lead-acid technologies are 95% used up at 11 volts for a 12-volt battery. See: http://www.aeroelectric.com/Pictures/Curves/Capacity_vs_Voltage.gif This is a curve for a big biz jet battery where we see that for "light" loads (1 to 2x of capacity), the discharge voltage has a sharp "knee" that increases the negative going slope as it crosses 11v/22v line. This particular battery is capacity rated at CC levels of discharge i.e., it's a 37 a.h. battery that will give 100% of rated capacity at 74 amps of discharge (typical for rating bizjet batteries that have a 30 minute emergency requirement). If one were to discharge this battery like most of the rest of the industry does (20 hour rate) then it would probably exhibit a capacity on the order of 50 ampere-hours. Check out this curve from the datasheet on a Panasonic 33 a.h. battery: http://www.aeroelectric.com/Pictures/Curves/LA1233_Panasonic.gif Again, note the shape knee in the curve as it dives through 11 volts . . . all used up. In this case, the battery is not specifically rated for emergency power service in airplanes - it couldn't be called a 33 a.h. device. If we run up the 30-minute line to 11 volts, we find that the battery would have to be rated as a 26 a.h. device if intended for that kind of service. HERE'S THE POT HOLE - THE 30 MINUTE DISCHARGE CURVE OF 26.4 AMPS SAYS THE CAPACITY IS 26.4A X 0.5 HOURS OR 13.2 A.H., NOT 26 A.H. I SHOULD HAVE CAUGHT THAT . . . A 33 TO 26 REDUCTION IN APPARENT CAPACITY FOR A 15X LARGER DISCHARGE RATE DIDN'T RAISE THE FLAGS. FOUND IT WHILE ARCHIVING THE POST. Bob . . . ________________________________ Message 21 ____________________________________ Time: 08:40:47 AM PST US From: "Robert L. Nuckolls, III" from starter contactor Subject: Re: AeroElectric-List: ANL Current Limiter more than 6 inches from starter contactor --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" from starter contactor At 07:44 PM 2/13/2006 -0500, you wrote: >--> AeroElectric-List message posted by: STEVE MASSARI > > >All of the Aeroelectric 'Z' diagrams show the ANL current limiter mounted >within 6 inches of the starter contactor. I would like to mount mine on >the right side of the battery on a RV9. What wire size would you use ? I >am using the B&C base with a 60A fuse. The 6" figure for acceptable runs of un-protected wire is a rule-of-thumb long practiced in certified aviation. Admittedly, it's most often applied to small wires . . . the kinds that come off the busses to supply varios accessories. The alternator b-lead is a major distribution feeder and is one of the biggest wires in the airplane. Major feeders are not generally "protected". This practice is supported by decades of service history and failure data. The goal is to put any form of circuit protection for a wire as close as practical to the source of the energy that will burn the wire. Likelihood that departures from the 6" 'rule' is going to cause you grief in the future is exceedingly small. My personal choice for all fat wires in closely located battery/bus/alternator installations is 4AWG. Bob . . . ________________________________ Message 22 ____________________________________ Time: 08:44:28 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Strange alternator behavior at Startup --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:28 AM 2/23/2006 -0500, you wrote: >--> AeroElectric-List message posted by: "Stewart, Michael (ISS Atlanta)" > > >Thanks Bob, >Is the behavior of the alt continuing to charge after the field wire is >killed, normal behavior? Probably . . . the "field" wire is really a command wire to the internal regulator and has no direct responsibility for carrying field current. >Means I have no way to stop the alternator once its alive, except for >the crowbar protection on the alternator contactor, which I have not >verified actually works. Yup, that's the nature of the beast. >I don't have a way to kill it in a car driving down the road so I guess >this should not bother me, somehow it does. You've apparently missed a few megabytes worth of discussion on this topic. For a review, see: http://aeroelectric.com/articles/Alternator_Failures.pdf I'm working on a one-size-fits-all solution adaption of Z-24. If you have Z-24 installed, drive on. The Band-Aid is coming. Bob . . . ________________________________ Message 23 ____________________________________ Time: 09:15:33 AM PST US Subject: RE: AeroElectric-List: Strange alternator behavior at Startup From: "Stewart, Michael (ISS Atlanta)" --> AeroElectric-List message posted by: "Stewart, Michael (ISS Atlanta)" Oh no I have not missed them. Read them all till I was blurry eyed, dazed and confused. I love this list. So many smart people helping each other. It continues to amaze me. Mike Even after all the alternator discussions, not sure anything really sank in. Too much of a good thing maybe Do not archive -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Thursday, February 23, 2006 11:44 AM Subject: RE: AeroElectric-List: Strange alternator behavior at Startup --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:28 AM 2/23/2006 -0500, you wrote: >--> AeroElectric-List message posted by: "Stewart, Michael (ISS Atlanta)" > > >Thanks Bob, >Is the behavior of the alt continuing to charge after the field wire is >killed, normal behavior? Probably . . . the "field" wire is really a command wire to the internal regulator and has no direct responsibility for carrying field current. >Means I have no way to stop the alternator once its alive, except for >the crowbar protection on the alternator contactor, which I have not >verified actually works. Yup, that's the nature of the beast. >I don't have a way to kill it in a car driving down the road so I guess >this should not bother me, somehow it does. You've apparently missed a few megabytes worth of discussion on this topic. For a review, see: http://aeroelectric.com/articles/Alternator_Failures.pdf I'm working on a one-size-fits-all solution adaption of Z-24. If you have Z-24 installed, drive on. The Band-Aid is coming. Bob . . . ________________________________ Message 24 ____________________________________ Time: 09:21:24 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Z-14 Question --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:17 PM 2/11/2006 -0500, you wrote: >--> AeroElectric-List message posted by: JOHNATHAN MACY > > >Bob, > >The primary small gage wiring on the design is 4 AWG. Between the cross >feed contactor and the main battery contactor you show a 2 AWG. This is >the only place on the design that is using a 2 AWG wire. Why does it need >to be 2 AWG? Will 4 AWG work? > >Thanks, >Johnathan Keep in mind these are architecture drawings. Details as to wire sizing, fuse/breaker sizing, etc are variables that need attention during the design of YOUR system. The Z-figures are not all combed for agreement of the variables. If 4AWG was adequate for the fat wires in the rest of your system, then 2AWG is not necessary to jumper contactors. Bob . . . < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ________________________________ Message 25 ____________________________________ Time: 09:44:02 AM PST US From: "John Burnaby" Subject: Re: AeroElectric-List: Grab-bar FW penetration --> AeroElectric-List message posted by: "John Burnaby" Mickey, Bruce, and Bob, Thanks all, for your help. John do not archive ________________________________ Message 26 ____________________________________ Time: 10:23:00 AM PST US From: "D Wysong" Subject: Re: AeroElectric-List: EFIS Info --> AeroElectric-List message posted by: "D Wysong" Anyone have a link for "Pinpoint Inertial, Inc." (the new supplier)? I've happily used XBow IMUs in the past but have never even heard of the other guys. D ------- On 2/23/06, Bob C. wrote: > > DIRECT-TO AVIONICS ISSUES RECALL ON ALL CROSSBOW 425EX AHRS > ________________________________ Message 27 ____________________________________ Time: 10:23:00 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Strange alternator behavior at Startup --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:11 PM 2/23/2006 -0500, you wrote: >--> AeroElectric-List message posted by: "Stewart, Michael (ISS Atlanta)" > > >Oh no I have not missed them. Read them all till I was blurry eyed, >dazed and confused. I love this list. So many smart people helping each >other. It continues to amaze me. Even after all the alternator >discussions, not sure anything really sank in. Too much of a good >thing maybe . . . (do not archive) Okay, in the simplest terms: Install any internally regulated alternator of your choice. Know that the reliability of whatever you choose (as long as it's not a junkyard dog) is as good or better than anything flying in certified ships . . . and we don't avoid flying that rental machine because of our perceptions of alternators and batteries they may carry. Probability of OV condition is very low but not zero. Given the current capability of the alternator, it's prudent to ASSUME an OV condition can happen and plan for it . . . just as we've done in certified ships for 70 years. Know that some alternators recommended to the OBAM aircraft community have control issues. Some if not most cannot be turned ON/OFF at will any time under any conditions. If this is a design goal you embrace, know that techniques are in development to meet that goal. If this is not a goal you embrace, then the system as recommended by Van's and others does what it says it will do . . . power your airplane with relatively low risk even if you cannot control it. 99% of the past year's discussion on this topic dragged a lot of peripheral and mostly irrelevant discourse that did not advance the state of our art and science. We'll endeavor to stay focused on simple-ideas and elegant solutions for the future. Not too much of a good thing my friend . . . too much of irrelevant things. I've been taking flack from some cool headed observers for letting "my List" get out of control. I've never wanted to consider this List as a personal possession. I did start it . . . but with the idea of planting seeds that would grow on their own. However, it's entirely appropriate to treat the List as a classroom where ALL teachers are invited to practice their art and craft. Seeds need water, sun, nutrients and protection from destructive forces. Folks who just dig up seedlings and throw dirt should be invited to modify their modus operandi or take their shovels someplace else. I'll invite other teachers who participate on this List to join me in maintaining the loftiest goals in classroom atmosphere and decorum. Keep in mind that anytime you have simple-ideas (obvious truths) to share that will assemble into elegant solutions, you too have an opportunity to be a teacher. Bob . . . ________________________________ Message 28 ____________________________________ Time: 10:48:37 AM PST US From: "Pat Hatch" Subject: RE: AeroElectric-List: EFIS Info --> AeroElectric-List message posted by: "Pat Hatch" www.pinpointinertial.com Interestingly, if you google them, you get nothing, not even on GADAHARS. Pat -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of D Wysong Sent: Thursday, February 23, 2006 1:19 PM Subject: Re: AeroElectric-List: EFIS Info --> AeroElectric-List message posted by: "D Wysong" Anyone have a link for "Pinpoint Inertial, Inc." (the new supplier)? I've happily used XBow IMUs in the past but have never even heard of the other guys. ________________________________ Message 29 ____________________________________ Time: 11:00:06 AM PST US From: Bill Dube Subject: AeroElectric-List: Handy Battery Cpacity Calculator (was: Odyssey % of charge) --> AeroElectric-List message posted by: Bill Dube The Peukert calculator at the bottom of this web page is very useful for determining the capacity of a particular battery under some load other than the rates given in the specifications. http://www.geocities.com/CapeCanaveral/Lab/8679/battery.html You plug in the 20 hr rate and the reserve capacity (or the capcity at some other rate) and the webpage calculates the Peukert exponent. You them move down a bit and plug in the load of interest and the web page will calculate the capacity at that load. Quite handy. Very useful. Keep in mind that the temperature of the battery has a big effect. The capacity goes down the toilet on a lead-acid battery when it gets cold. Bill Dube' ________________________________ Message 30 ____________________________________ Time: 11:26:02 AM PST US From: "D Wysong" Subject: Re: AeroElectric-List: EFIS Info --> AeroElectric-List message posted by: "D Wysong" Doh! Thanks Pat! I came up dry with Google and didn't even consider the brute force approach. First my spell checker eliminates my ability to spell.... and now Google has eliminated my ability to find websites manually. A true slave to teknowlogee... er... technology... :-) D do not archive -------- On 2/23/06, Pat Hatch wrote: > --> AeroElectric-List message posted by: "Pat Hatch" > > www.pinpointinertial.com > > Interestingly, if you google them, you get nothing, not even on GADAHARS. > > Pat ________________________________ Message 31 ____________________________________ Time: 12:05:49 PM PST US From: "Ed Anderson" Subject: Re: AeroElectric-List: EFIS Info --> AeroElectric-List message posted by: "Ed Anderson" If you noticed the comment at the bottom of their page We are currently accepting dealer and OEM inquiries only. Click here to e-mail us. Clearly not interested in talking to the individual builder, so appears they are looking for someone to use their unit in an EFIS in a production run. Too, bad, I'd like to get one to see what could be done with it. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com ----- Original Message ----- From: "Pat Hatch" Sent: Thursday, February 23, 2006 1:46 PM Subject: RE: AeroElectric-List: EFIS Info > --> AeroElectric-List message posted by: "Pat Hatch" > > www.pinpointinertial.com > > Interestingly, if you google them, you get nothing, not even on GADAHARS. > > Pat > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of D > Wysong > Sent: Thursday, February 23, 2006 1:19 PM > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: EFIS Info > > --> AeroElectric-List message posted by: "D Wysong" > > Anyone have a link for "Pinpoint Inertial, Inc." (the new supplier)? > I've happily used XBow IMUs in the past but have never even heard of > the other guys. > > > ________________________________ Message 32 ____________________________________ Time: 12:10:28 PM PST US From: Subject: AeroElectric-List: Re: Strange alternator behavior at Startup --> AeroElectric-List message posted by: Jon, Jon, excellent great reply to Michael. I agree and well stated. I would add two things to what Michael wrote: > Killing the alt field wire will not kill the alternator once she is > making current. Which I believe is proper behavior with this > alternator. -DO NOT (ever) switch IGN lead ON or OFF w/ engine running (possible damage) ( To nit pick *alt field wire* is an IGN wire not field & not intended for this use.) > "then give her some rpm up above 1100rpm, voltage and amp charge > slowly come up to proper level. Takes about 4 seconds for it to come > up." -Consider idling at 1100 RPM initially (as recommend by Sacramento Sky Ranch) (one of the best books around: http://www.sacskyranch.com/pubsem.htm ) I don't see any problem and concur with Jon it sounds like the SOFT START feature of the alternators regulator. Just stop messing with the IGN lead (you called alt field). George PS (IGN wire is a small signal to tell the regulator to go to work or go to sleep. It was not intended to control the regulator while running. The FIELD wire is internal to the alternator and you do not have direct access to the field. Turning the IGN wire ON and OFF while under load has been known to cause problems. In the original applications for this alternator the IGN wire is NEVER switched while the alternator is running. Whether it can control the alternator while running or not is not important. Also you know NOT to ever trip the crow bar intentionally while running. This WILL damage the alternator. ) From: Jon Goguen Subject: Re: Strange alternator behavior at Startup These modern IR regulators are are "intelligent", the IQ depending on the particular model. Like me, some need to warm up before it they think well enough to work. Many have a ramp function to bring the output current up slowly at low rpm to prevent sudden engine loading when alternator torque would be high, so the slow ramp up of the output isn't surprising. 35 degrees seems pretty warm to be seeing such a long warm-up delay, and it's possible that the regulator IC is defective for low temp operation. If you can trace the problem directly to the regulator, say by warming it with a hair dryer before starting on a cold day, you might consider replacing it, perhaps with an external one that doesn't try to be quite so clever. Another possibility is that the belt slips in the cold when it's a little bit stiff, and the the alternator rpm drops below the minimum at which the regulator will turn on the output. Many regulators keep the output off below a minimum rpm, to prevent loading the engine during startup. You might not be getting above this threshold until the belt warms up and grabs better. Jon Jon Goguen jon.goguen@umassmed.edu Central Massachusetts Kitfox Series V Rotax 912S / N456JG (reserved) Complete except for electrics and avionics From: Stewart, Michael (ISS Atlanta) wrote: > --> AeroElectric-List message posted by: "Stewart, Michael (ISS > Atlanta)" > > I have a 60amp internally regulated ND alternator with the alternator > contactor and crowbar protection on it. > > In cold weather, say below 35degreesF, on initial start, I have no > charge. If I let her sit for a few minutes at 800rpm and worm up a > little, then give her some rpm up above 1100rpm, voltage and amp charge > slowly come up to proper level. Takes about 4 seconds for it to come > up. > If I don't raise the rpm and just let her idle at 800, then after about > 10 minutes of warming up, the same behavior happens where the voltage > slowly comes up. I do not get this behavior when its above 40 degrees > F, > nor do I get this behavior if it has been run already. > > > Killing the alt field wire will not kill the alternator once she is > making current. Which I believe is proper behavior with this > alternator. > > > Thoughts? > > Thanks > > Mike > > RV-8 io-540 --------------------------------- ________________________________ Message 33 ____________________________________ Time: 12:11:07 PM PST US Subject: RE: AeroElectric-List: Strange alternator behavior at Startup From: "Stewart, Michael (ISS Atlanta)" --> AeroElectric-List message posted by: "Stewart, Michael (ISS Atlanta)" Thanks for that response. I turn it on, it works. I press on. Ill try and nail down the temperature issue while the temps are low. Not sure how to troubleshoot without just replacing it and seeing if it disappears. Not sure if replacing it is worth the hassle since it come on-line eventually. Thanks for the long note bob. I always enjoy reading them. Mike -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Thursday, February 23, 2006 1:21 PM Subject: RE: AeroElectric-List: Strange alternator behavior at Startup --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:11 PM 2/23/2006 -0500, you wrote: >--> AeroElectric-List message posted by: "Stewart, Michael (ISS Atlanta)" > > >Oh no I have not missed them. Read them all till I was blurry eyed, >dazed and confused. I love this list. So many smart people helping each >other. It continues to amaze me. Even after all the alternator >discussions, not sure anything really sank in. Too much of a good >thing maybe . . . (do not archive) Okay, in the simplest terms: Install any internally regulated alternator of your choice. Know that the reliability of whatever you choose (as long as it's not a junkyard dog) is as good or better than anything flying in certified ships . . . and we don't avoid flying that rental machine because of our perceptions of alternators and batteries they may carry. Probability of OV condition is very low but not zero. Given the current capability of the alternator, it's prudent to ASSUME an OV condition can happen and plan for it . . . just as we've done in certified ships for 70 years. Know that some alternators recommended to the OBAM aircraft community have control issues. Some if not most cannot be turned ON/OFF at will any time under any conditions. If this is a design goal you embrace, know that techniques are in development to meet that goal. If this is not a goal you embrace, then the system as recommended by Van's and others does what it says it will do . . . power your airplane with relatively low risk even if you cannot control it. 99% of the past year's discussion on this topic dragged a lot of peripheral and mostly irrelevant discourse that did not advance the state of our art and science. We'll endeavor to stay focused on simple-ideas and elegant solutions for the future. Not too much of a good thing my friend . . . too much of irrelevant things. I've been taking flack from some cool headed observers for letting "my List" get out of control. I've never wanted to consider this List as a personal possession. I did start it . . . but with the idea of planting seeds that would grow on their own. However, it's entirely appropriate to treat the List as a classroom where ALL teachers are invited to practice their art and craft. Seeds need water, sun, nutrients and protection from destructive forces. Folks who just dig up seedlings and throw dirt should be invited to modify their modus operandi or take their shovels someplace else. I'll invite other teachers who participate on this List to join me in maintaining the loftiest goals in classroom atmosphere and decorum. Keep in mind that anytime you have simple-ideas (obvious truths) to share that will assemble into elegant solutions, you too have an opportunity to be a teacher. Bob . . . ________________________________ Message 34 ____________________________________ Time: 12:26:46 PM PST US From: "Kingsley Hurst" Subject: RE: AeroElectric-List: Topic with a little difference --> AeroElectric-List message posted by: "Kingsley Hurst" >I'm told that when welding on a vehicle that has an alternator, the >diodes in the alternator can be damaged if the battery is not >disconnected first. Fact or fiction ? Bob and Brian, Thank you both for your considered opinions. I was not clever enough to deduce for myself the scenario you described Brian, but I am able to understand what you have said and agree the chances of this happening should be very low. BTW, people who have told me of this phenomenon were not welding cracked chassis so ??? I have always been very sceptical of the claim but as I said, I didn't know so I am heartened to learn my scepticism had some foundation. Once again, I sincerely appreciate your willingness to share your knowledge with us. Best regards Kingsley in Oz Do not archive ________________________________ Message 35 ____________________________________ Time: 12:26:46 PM PST US From: Mickey Coggins Subject: AeroElectric-List: Avionics ground bus kit --> AeroElectric-List message posted by: Mickey Coggins Hi, I vaguely recall hearing that someone was putting together a kit or perhaps a finished avionics ground bus like Bob shows in this photo: http://www.aeroelectric.com/Pictures/Grounding/Avionics_Bus_3.jpg Does anyone know where I can purchase either the kit or (preferably) the finished product? Thanks, Mickey -- Mickey Coggins http://www.rv8.ch/ #82007 finishing ________________________________ Message 36 ____________________________________ Time: 12:38:32 PM PST US Subject: RE: AeroElectric-List: Re: Strange alternator behavior at Startup From: "Stewart, Michael (ISS Atlanta)" --> AeroElectric-List message posted by: "Stewart, Michael (ISS Atlanta)" Copy All George. New rule. No need for an alt field switch. IGN lead should just be on the master buss and be done with it. Don't Kill master when its running. Thanks Mike -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of gmcjetpilot@yahoo.com Sent: Thursday, February 23, 2006 3:09 PM Subject: [ ] AeroElectric-List: Re: Strange alternator behavior at Startup --> AeroElectric-List message posted by: Jon, Jon, excellent great reply to Michael. I agree and well stated. I would add two things to what Michael wrote: > Killing the alt field wire will not kill the alternator once she is > making current. Which I believe is proper behavior with this > alternator. -DO NOT (ever) switch IGN lead ON or OFF w/ engine running (possible damage) ( To nit pick *alt field wire* is an IGN wire not field & not intended for this use.) > "then give her some rpm up above 1100rpm, voltage and amp charge > slowly come up to proper level. Takes about 4 seconds for it to come > up." -Consider idling at 1100 RPM initially (as recommend by Sacramento Sky Ranch) (one of the best books around: http://www.sacskyranch.com/pubsem.htm ) I don't see any problem and concur with Jon it sounds like the SOFT START feature of the alternators regulator. Just stop messing with the IGN lead (you called alt field). George PS (IGN wire is a small signal to tell the regulator to go to work or go to sleep. It was not intended to control the regulator while running. The FIELD wire is internal to the alternator and you do not have direct access to the field. Turning the IGN wire ON and OFF while under load has been known to cause problems. In the original applications for this alternator the IGN wire is NEVER switched while the alternator is running. Whether it can control the alternator while running or not is not important. Also you know NOT to ever trip the crow bar intentionally while running. This WILL damage the alternator. ) From: Jon Goguen Subject: Re: Strange alternator behavior at Startup These modern IR regulators are are "intelligent", the IQ depending on the particular model. Like me, some need to warm up before it they think well enough to work. Many have a ramp function to bring the output current up slowly at low rpm to prevent sudden engine loading when alternator torque would be high, so the slow ramp up of the output isn't surprising. 35 degrees seems pretty warm to be seeing such a long warm-up delay, and it's possible that the regulator IC is defective for low temp operation. If you can trace the problem directly to the regulator, say by warming it with a hair dryer before starting on a cold day, you might consider replacing it, perhaps with an external one that doesn't try to be quite so clever. Another possibility is that the belt slips in the cold when it's a little bit stiff, and the the alternator rpm drops below the minimum at which the regulator will turn on the output. Many regulators keep the output off below a minimum rpm, to prevent loading the engine during startup. You might not be getting above this threshold until the belt warms up and grabs better. Jon Jon Goguen jon.goguen@umassmed.edu Central Massachusetts Kitfox Series V Rotax 912S / N456JG (reserved) Complete except for electrics and avionics From: Stewart, Michael (ISS Atlanta) wrote: > --> AeroElectric-List message posted by: "Stewart, Michael (ISS > Atlanta)" > > I have a 60amp internally regulated ND alternator with the alternator > contactor and crowbar protection on it. > > In cold weather, say below 35degreesF, on initial start, I have no > charge. If I let her sit for a few minutes at 800rpm and worm up a > little, then give her some rpm up above 1100rpm, voltage and amp charge > slowly come up to proper level. Takes about 4 seconds for it to come > up. > If I don't raise the rpm and just let her idle at 800, then after about > 10 minutes of warming up, the same behavior happens where the voltage > slowly comes up. I do not get this behavior when its above 40 degrees > F, > nor do I get this behavior if it has been run already. > > > Killing the alt field wire will not kill the alternator once she is > making current. Which I believe is proper behavior with this > alternator. > > > Thoughts? > > Thanks > > Mike > > RV-8 io-540 --------------------------------- ________________________________ Message 37 ____________________________________ Time: 12:40:44 PM PST US From: Mickey Coggins Subject: Re: AeroElectric-List: Re: Strange alternator behavior at Startup --> AeroElectric-List message posted by: Mickey Coggins > (IGN wire is a small signal to tell the regulator to go to work or go to sleep. > It was not intended to control the regulator while running. The FIELD wire is > internal to the alternator and you do not have direct access to the field. > Turning the IGN wire ON and OFF while under load has been known to cause > problems. In the original applications for this alternator the IGN wire is NEVER > switched while the alternator is running. Quick question - what happens if you are driving down the highway at 100 mph, everything working fine, and you turn the key off? Will the alternator stop generating juice? Will all your stuff fry? I have not tried this in my car in a long time, probably since the 70s - back before the key locked the steering wheel. -- Mickey Coggins http://www.rv8.ch/ #82007 finishing do not archive ________________________________ Message 38 ____________________________________ Time: 01:29:11 PM PST US From: "Dave Morris \"BigD\"" Startup Subject: Re: AeroElectric-List: Re: Strange alternator behavior at Startup --> AeroElectric-List message posted by: "Dave Morris \"BigD\"" Startup You'll probably find out why the behemoth you're driving has power steering and power brakes! And then you'll wish you hadn't turned off the motor. :) Dave Morris At 02:39 PM 2/23/2006, you wrote: >--> AeroElectric-List message posted by: Mickey Coggins > > > >Quick question - what happens if you are driving down the highway >at 100 mph, everything working fine, and you turn the key off? >Will the alternator stop generating juice? Will all your stuff >fry? I have not tried this in my car in a long time, probably >since the 70s - back before the key locked the steering wheel. > >-- >Mickey Coggins >http://www.rv8.ch/ >#82007 finishing > > >do not archive > > ________________________________ Message 39 ____________________________________ Time: 01:46:51 PM PST US Subject: RE: AeroElectric-List: Topic with a little difference From: --> AeroElectric-List message posted by: "welding on a vehicle that has an alternator, the diodes in the alternator can be damaged if the battery is not disconnected first. Fact or fiction ?" For what it's worth, I have TIG welded on Automobiles here and there. Chassis, exhaust and motor). I never had a alternator failure, never disconnected battery. Did remove battery a few times when welding near it, precaution in case some hydrogen decided to follow my puddle round. That said, when welding with DC, many TIGs have a high frequency AC start to help easily establish an arc. Also when welding Aluminium you use AC all the time. Once in a great while when welding DC, especial in awkward positions, the torch electrode can hit the welding rod, instantly stopping the arc and insulating the rod from the grounded work area. Now for tacking purposes don't have gloves in rod hand (left), and somehow for balance purposes have right arm resting on grounded work area. Of course it all happens when high frequency is happening. OUCH!!!!! Do that just once and at least you will rest arm on something semi insulated. When this happens if you pull away and are less than immediate on stopping electron flow, if the now welded rod onto the electrode has a nice long extension of it. If you left a can of your favorite beverage on the welding table, if it was carbonated, closed and sticky it "Will" get punctured at this precise time. This holds true for your electronics project that is laid out at the far end of the welding table that could not possibly get hurt so far away (the only free table area in shop). Resting on work that you think is grounded to table will give you a jolt as well especial if some other part of yuor body is better grounded. When TIG welding, always consider just how far that rod can reach when you get zapped and jerk away. Use shorter rod, or cover stuff that is critical. It is good practice to always make a rounded bend with a needle nose pliers on end of rod that can get you or others when welding in tight awkward positions. I forget exact voltages, think 28 or 30 for both DC and AC, AC hurts a lot more. Ron Parigoris ________________________________ Message 40 ____________________________________ Time: 02:03:28 PM PST US Subject: Re: AeroElectric-List: Re: Strange alternator behavior at Startup From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" Actually, if you turn the key off, and the engine continues to turn, the power steering will probably continue to work. Except on vehicles with variable electric power assist (some Hondas and BMWs, and undoubtedly others too).. > --> AeroElectric-List message posted by: "Dave Morris \"BigD\"" > Startup > > You'll probably find out why the behemoth you're driving has power > steering and power brakes! And then you'll wish you hadn't turned off > the motor. :) > Dave Morris > > At 02:39 PM 2/23/2006, you wrote: >>--> AeroElectric-List message posted by: Mickey Coggins >> >> >> >>Quick question - what happens if you are driving down the highway at >> 100 mph, everything working fine, and you turn the key off? >>Will the alternator stop generating juice? Will all your stuff >>fry? I have not tried this in my car in a long time, probably >>since the 70s - back before the key locked the steering wheel. >> >>-- >>Mickey Coggins >>http://www.rv8.ch/ >>#82007 finishing >> >> >>do not archive >> >> >> >> >> >> >> >> >> > > ________________________________ Message 41 ____________________________________ Time: 02:03:29 PM PST US Subject: Re: AeroElectric-List: Re: Strange alternator behavior at Startup From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" Cars are not wired the way it has been sometimes proposed that we wire airplanes... If you turn the key off, the B-lead on the alternator remains connected to the battery - controlling any load dump condition... > --> AeroElectric-List message posted by: Mickey Coggins > > >> (IGN wire is a small signal to tell the regulator to go to work or go >> to sleep. It was not intended to control the regulator while running. >> The FIELD wire is internal to the alternator and you do not have >> direct access to the field. Turning the IGN wire ON and OFF while >> under load has been known to cause problems. In the original >> applications for this alternator the IGN wire is NEVER switched while >> the alternator is running. > > Quick question - what happens if you are driving down the highway > at 100 mph, everything working fine, and you turn the key off? > Will the alternator stop generating juice? Will all your stuff > fry? I have not tried this in my car in a long time, probably > since the 70s - back before the key locked the steering wheel. > > -- > Mickey Coggins > http://www.rv8.ch/ > #82007 finishing > > > do not archive > > ________________________________ Message 42 ____________________________________ Time: 02:06:38 PM PST US Subject: Re: AeroElectric-List: Re: Strange alternator behavior at Startup From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" Wait a minute George.. I think the only thing that we have possibly speculated that would cause alternator damage was disconnecting the B-lead (the output) from the main bus (including the battery) while the alternator was producing power. That's the whole "load-dump" scenario which the is introduced by the inclusion of the b-lead contactor. Do you know of another failure mode associated with toggling the control lead to the alternator? I must have missed something in the discussion. Regards, Matt- > --> AeroElectric-List message posted by: > > Jon, > > Jon, excellent great reply to Michael. > > I agree and well stated. I would add two things to what Michael wrote: > > > Killing the alt field wire will not kill the alternator once > she is > > making current. Which I believe is proper behavior with this > alternator. > > -DO NOT (ever) switch IGN lead ON or OFF w/ engine running (possible > damage) > ( To nit pick *alt field wire* is an IGN wire not field & not > intended for this use.) > > > "then give her some rpm up above 1100rpm, voltage and amp > charge > > slowly come up to proper level. Takes about 4 seconds for it to > come up." > > > -Consider idling at 1100 RPM initially (as recommend by Sacramento Sky > Ranch) (one of the best books around: > http://www.sacskyranch.com/pubsem.htm ) > > I don't see any problem and concur with Jon it sounds like the SOFT > START feature of the alternators regulator. Just stop messing with the > IGN lead (you called alt field). > > > George > > PS > (IGN wire is a small signal to tell the regulator to go to work or go to > sleep. It was not intended to control the regulator while running. The > FIELD wire is internal to the alternator and you do not have direct > access to the field. Turning the IGN wire ON and OFF while under load > has been known to cause problems. In the original applications for this > alternator the IGN wire is NEVER switched while the alternator is > running. Whether it can control the alternator while running or not is > not important. Also you know NOT to ever trip the crow bar > intentionally while running. This WILL damage the alternator. ) > > > From: Jon Goguen > Subject: Re: Strange alternator behavior at Startup > > > These modern IR regulators are are "intelligent", the IQ depending > on the particular model. Like me, some need to warm up before it > they think well enough to work. Many have a ramp function to > bring the output current up slowly at low rpm to prevent sudden > engine loading when alternator torque would be high, so the slow > ramp up of the output isn't surprising. 35 degrees seems pretty > warm to be seeing such a long warm-up delay, and it's possible > that the regulator IC is defective for low temp operation. If > you can trace the problem directly to the regulator, say by > warming it with a hair dryer before starting on a cold day, you > might consider replacing it, perhaps with an external one that > doesn't try to be quite so clever. Another possibility is that > the belt slips in the cold when it's a little bit stiff, and the > the alternator rpm drops below the minimum at which the regulator > will turn on the output. Many regulators keep the output off > below a minimum rpm, to prevent loading the engine during startup. > You might not be getting above this threshold until the belt > warms up and grabs better. > > Jon > > > Jon Goguen > jon.goguen@umassmed.edu > Central Massachusetts > Kitfox Series V Rotax 912S / N456JG (reserved) > Complete except for electrics and avionics > > > From: Stewart, Michael (ISS Atlanta) wrote: > > > --> AeroElectric-List message posted by: "Stewart, Michael (ISS > Atlanta)" > > > > I have a 60amp internally regulated ND alternator with the > alternator contactor and crowbar protection on it. > > > > In cold weather, say below 35degreesF, on initial start, I have > no charge. If I let her sit for a few minutes at 800rpm and worm > up a little, then give her some rpm up above 1100rpm, voltage > and amp charge slowly come up to proper level. Takes about 4 > seconds for it to come up. > > If I don't raise the rpm and just let her idle at 800, then > after about 10 minutes of warming up, the same behavior happens > where the voltage slowly comes up. I do not get this behavior > when its above 40 degrees F, > > nor do I get this behavior if it has been run already. > > > > > > Killing the alt field wire will not kill the alternator once she > is making current. Which I believe is proper behavior with this > alternator. > > > > > > Thoughts? > > > > Thanks > > > > Mike > > > > RV-8 io-540 > > > --------------------------------- > > ________________________________ Message 43 ____________________________________ Time: 02:52:40 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Avionics ground bus kit --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" I willed that product to Steinair at: http://steinair.com Bob . . . At 09:23 PM 2/23/2006 +0100, you wrote: >--> AeroElectric-List message posted by: Mickey Coggins > > >Hi, > >I vaguely recall hearing that someone was putting together >a kit or perhaps a finished avionics ground bus like Bob >shows in this photo: > >http://www.aeroelectric.com/Pictures/Grounding/Avionics_Bus_3.jpg > >Does anyone know where I can purchase either the kit or >(preferably) the finished product? > >Thanks, >Mickey >-- >Mickey Coggins >http://www.rv8.ch/ >#82007 finishing > > >-- > > Bob . . . < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ________________________________ Message 44 ____________________________________ Time: 03:08:22 PM PST US From: Jon Goguen Subject: Re: AeroElectric-List: Strange alternator behavior at Startup --> AeroElectric-List message posted by: Jon Goguen Bob, This comes from data sheets on modern alternator regulator ICs like http://www.freescale.com/files/analog/doc/data_sheet/MC33092A.pdf. The problem is that it's difficult to know how sophisticated the regulator is in any particular alternator, and exactly what features are implemented. For example, I suspect the small ND models intended for forklifts and similar uses have regulators with many fewer functions than the 70 amp versions intended for automotive use. The chip described in the attached data sheet does lots of things, not all of which are necessarily good things in an airplane. Have a good read! I think you'll find it revealing. Jon Jon Goguen jon.goguen@umassmed.edu Central Massachusetts Kitfox Series V Rotax 912S / N456JG (reserved) Complete except for electrics and avionics "Nothing worth knowing can be understood by the human mind" --Woody Allen On Feb 23, 2006, at 10:06 AM, Robert L. Nuckolls, III wrote: > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > At 01:26 PM 2/22/2006 -0500, you wrote: > >> --> AeroElectric-List message posted by: Jon Goguen >> >> >> These modern IR regulators are are "intelligent", the IQ depending on >> the particular model. LIke me, some need to warm up before it they >> think well enough to work. Many have a ramp function to bring the >> output current up slowly at low rpm to prevent sudden engine loading >> when alternator torque would be high, so the slow ramp up of the >> output >> isn't surprising. 35 degrees seems pretty warm to be seeing such a >> long warm-up delay, and it's possible that the regulator IC is >> defective for low temp operation. If you can trace the problem >> directly to the regulator, say by warming it with a hair dryer before >> starting on a cold day, you might consider replacing it, perhaps with >> an external one that doesn't try to be quite so clever. Another >> possibility is that the belt slips in the cold when it's a little bit >> stiff, and the the alternator rpm drops below the minimum at which the >> regulator will turn on the output. Many regulators keep the output off >> below a minimum rpm, to prevent loading the engine during startup. You >> might not be getting above this threshold until the belt warms up and >> grabs better. > > Can you point us to any published literature on this? Please > understand that I'm not attacking your assertions with any > kind of "PROVE IT" attitude. My request is driven by the simple > fact that many of my suggestions about the IR alternator have > been driven by what I KNOW about them (admittedly not much . . . > the automotive guys are not used to getting requests for such > data . . . their gazillions of automotive customers don't care). > A handful of idiots that want to put "automotive" stuff into > airplanes are not to be taken seriously. > > When I've crafted architectures and design philosophies that > assume NOTHING, I've had to field a barrage of cabbages and > tomatoes from congregations of certain beliefs because I don't > embrace their faith . . . when at the same time, the bibles > upon which their faith is based appear not to be in print. > My time to research such things is limited so I you (or anyone > else on the list) can point me to any descriptive literature > for any of the modern (or not so modern) products, I'd be > grateful. > > Bob . . . > > ________________________________ Message 45 ____________________________________ Time: 11:18:32 PM PST US From: "Scott" Subject: AeroElectric-List: What happens if OV trips? --> AeroElectric-List message posted by: "Scott" If the "crowbar" overvoltage protection trips, is it a permanent fault or something that can be reset on the fly? I'm interested in general in how it works, but specificly thinking now about the possibility of one alternator tripping both OV circuits if both alternators happen to be on (by design or switchology error). If that happened, would both alternators be permanently disabled or would turning off the faulty one allow the other to be brought back online? Thanks! Scott.