---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 02/14/06: 17 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:27 AM - Odyssey % of charge () 2. 04:53 AM - Re: Odyssey % of charge (Alex Peterson) 3. 10:06 AM - Softcomm C300 ANR Headset (Hoffmann D- Remscheid) 4. 11:43 AM - Re: Over-voltage event w/ IR alternator () 5. 01:25 PM - Re: Re: Over-voltage event w/ IR alternator (Matt Prather) 6. 01:27 PM - Re: Strobe power supplies was Wiring issues (Randy & Linda Nelson) 7. 03:18 PM - Re: Re: Over-voltage event w/ IR alternator (Brian Lloyd) 8. 03:48 PM - Z13-8 how to energize standby contactor? (Scott) 9. 03:56 PM - Z31-B Ground power disconnect? (Scott) 10. 04:03 PM - Z-13/8 Bad if both alternators on at once? (Scott) 11. 04:03 PM - Low Voltage Warn on E-Bus instead of Main? (Scott) 12. 04:44 PM - Re: Re: Over-voltage event w/ IR alternator (Dan Brown) 13. 04:59 PM - Re: Re: Over-voltage event w/ IR alternator (Robert L. Nuckolls, III) 14. 05:28 PM - Re: Strobe power supplies was Wiring issues (Charlie Kuss) 15. 05:30 PM - Re: Re: Over-voltage event w/ IR alternator (Ken) 16. 10:46 PM - instrument wiring (Chris & Kellie Hand) 17. 10:50 PM - dimmer ckt from Van's (Chris & Kellie Hand) ________________________________ Message 1 _____________________________________ Time: 12:27:58 AM PST US Subject: AeroElectric-List: Odyssey % of charge From: --> 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? Thx. Ron Parigoris ________________________________ Message 2 _____________________________________ Time: 04:53:18 AM PST US From: "Alex Peterson" Subject: RE: AeroElectric-List: Odyssey % of charge --> AeroElectric-List message posted by: "Alex Peterson" > --> 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? > > Thx. > Ron Parigoris Go to their website, there is a complete pdf for downloading. Alex Peterson RV6-A N66AP 714 hours Maple Grove, MN ________________________________ Message 3 _____________________________________ Time: 10:06:54 AM PST US From: "Hoffmann D- Remscheid" Subject: AeroElectric-List: Softcomm C300 ANR Headset --> AeroElectric-List message posted by: "Hoffmann D- Remscheid" Softcomm seems to have a new ANR headset concept avoiding the trouble with all the cables dangling around in the cockpit with the C300 ANR. As far as I understand it they use the bias voltage for the electret microphone for power recruitment which is surely very elegant. However I wonder whether that can be sufficient, as power requirements for active compensation are not negligible in a noisy environment. Any differences in intercoms behaviour with this respect? Anybody who has experiences (good or bad)? Thanks in advance Richard Hoffmann MCR4S Germany ________________________________ Message 4 _____________________________________ Time: 11:43:57 AM PST US From: Subject: AeroElectric-List: Re: Over-voltage event w/ IR alternator --> AeroElectric-List message posted by: Mr. Bob Lee Congratulation you had an overvoltage. You saw that it limited the voltage to 18 volts max. I think your volt meter is off and it was likely more like 17 volts, but that is what the ND alternators do. Their secondary voltage control limit is either 16v or 17v on some models. Not sure about a Ford alternator, but all I-VR alternators (really the only ones made now a day) use similar IC chip control in the VR and OV limit of 17v max. Even though you had an overvoltage you had some control and never exceeded 18 volts (17 volts?). Thanks for an excellent factual description with out sensational emotional and prejudicial comments. Yes an I-VR can have an OV but not the wild runaway that gets spread around like brown stinky stuff. Although OV is rare in the first place, this is typical overvoltage when it does happen. Bob and some dislike the I-VR because there is one transistor that controls the field. If that transistor failed (single point failure) it could in THEORY cause a high uncontrolled OV condition. NO one has proved this has EVER happened as they say. By prove I mean took a claimed runaway VR and determined the cause was this single point failure. Its RARE indeed. In practice the field transistor is bullet proof. Cooling air adds to the reliability of that or any transistor. Don't install a I-VR like a E-VR they are differnt by design. That is my only point I have tried to make in a year of fighting the anecdotal comments Bob and other's make. NO OFFENSE TO BOB. I agree the E-VR has MORE control or should say more DIRECT control of the fundamental thing that controls output, the field wire. THAT IS AN ADVANTAGE. (SEE I SAID IT, BUT THAT does not make I-VR bad.) However let's be real. I-VR are super reliable as is. Failures are rare and tend to be LOW voltage or NO voltage events. When there is a spike above the normal set voltage its a controllable event by adding load. Example in point: F150 Ford truck, IF YOU HAVE a pull-able CB in your FORD truck for the alternator output (b-lead), you would just pull the CB if the voltage was too high. Done deal. No need for extra protection or crow bars. HOWEVER I KNOW BOB'S philosophy that he likes automatic control. OK that is cool. However that comes at the expense of weight, complexity and potential nuisance trips that can damage a good alternator. BOB contradicts himself, saying don't use an I-VR at all? OK great advice, but a problem? NO ONE makes cheap off the shelf E-VR alternators? Why spend++$600 for B&C or GUT a perfectly good I-VR? Bottom line, Lee's alternator not only indicated the OV failure, which shows the value of using the warning light, the voltage never exceeded 18v (I think you volt gauge is off by a volt). WHAT IS WRONG WITH THAT? Most avionics can take anywhere from 10-30 volts all day with out fail and even a spike up to 60v for very short durations. HERE HERE Mr. Lee!!!!! Well done. I am putting you in my email post HALL OF FAME. I agree with all you points except point 6, your conclusion, but than its not that point 6 is incorrect. I can't fault anything you said. I just don't think its necessarily a needed. Of your 6 points I summit the following comments: 1) The alternator defaults to 18v (17v?) by design and typical. It is also NOT indicative of the claim that the field has gone crazy. There is a fault and it has lost some control, but it is NOT out of control. 2) One event does not make a case, but your experience is typical. In the rare cases of OV (anything over 14.5v). 3) Check list are great 4) Z-13 would but so would reach over and pulling a CB on the B-lead. I am not sure turning the IGN "signal" to tell the VR to go to sleep will work every time. Bob says he does not recommend I-VR at all any more any way, so if you are a disciple of his doctrine the solution is obvious. I have no issue with that. 5) I think it is worth the risk of good debate. 6) I am glad for you all the best. What ever makes you sleep at night. By the way Ford alternators have a bad service history according to the NHTSA (Nits-a) (National Highway Traffic Safety Administration). ND alternators are as prolific and have a spotless record in regards to consumer complain, service bulletins and recalls. My points are: a) use the warning light; it is a fault light not just a no charge light. If you don't use the warning light, have something to indicate a charge fault (hi/lo volts). b) Do not turn the alternator on and off under load. c) Wire it (the ND alternator Van sells) just like I show below. Which is a copy of how it works in the Suzuki Samurai it was designed for with one addition for aircraft use, the 50-60 amp pull-able CB in the panel. d) If you want an I-VR and an OV relay and crow bar, that is fine but you would be better off going to an external VR if you can't live with the I-VR as is, which is Bob Lee's conclusion. I can't fault you for that. DO what makes you happy. http://img116.imageshack.us/my.php?image=altwiring5cm.jpg A modified Toyota diagram. http://img110.imageshack.us/my.php?image=toyota7gf.jpg Flame Suit on. BTW please actually read what I wrote first. I said external VR's are better in that you have direct access to the field wire. I also said I agree with Bob N and Bob L and understand the desire to either use an OV module/relay on an I-VR or use an E-VR. I AGREE. Back off. The only point I need to make is OV events with I- VR's are rare, which Bob Lee made for me. I also need to point out the SO CALLED overvoltage event was a NON EVENT. In a car or plane it does little to nothing since most devices can live on 17volts (or even 18 volts as Bob Lee said, which I think is a little high). AT LEAST this event was well document and valid case to evaluate and its impact on aircraft operations. Obviously Mr. Lee in his F150 could just pull over and CRASH LAND on the shoulder of the road. In a plane pulling over and parking on a cloud is not possible. However that is what a battery is for. Sincerely George Nomex flame suit on. From: Subject: Over-voltage event w/ IR alternator Message posted by: Yesterday morning on the way to church I noticed the alternator idiot Light come on. A quick check of the volt meter indicated 18 volts. I was Driving my son's 1990 Ford F-150 with an IR alternator. It took me about Thirty seconds to figure out what to do. There was not enough time left Before church to make a forced landing so I kept flying. I started turning on anything electrical to absorb the extra electrons that were smashing the battery. When I remembered the off road driving lights my son recently installed and turned them on I was down to 13 volts. The voltage would vary with RPM and as long as I kept everything on and the RPM below 1500 I could keep the voltage under 14 volts. As the truck accelerated away from a stop and the transmission was in lower gears the idiot light would come on each time the voltage was above 16 volts which happened around 2000 RPM. Once in high gear the RPM would settle around 1200 and the voltage would be around 13 volts. In thirty years of driving I would guess that I have had five or six alternator failures. This is the first time it has been a high voltage failure. All of the other times it has been low output failures. Conclusions: 1. some IR alternators out there will detect an overvoltage event (turn on the idiot light) and yet do nothing about it (continue to produce 18 volts). 2. one event does not make conclusive science 3. a check list for OV events would have solved this problem quicker. I need a plan for low frequency failures with simple solutions. 4. z-13 would have handled this problem in my airplane as the main alternator would have tripped the OV module; the low voltage tone in my earphones would alert me to turn on the standby alternator and flight would have continued to destination. 5. what I learned from conclusions 1, 3, and 4 is worth the risk of starting another IR alternator e-mail flood. 6. I'm glad I removed the IR regulator from my plane's alternator And replaced it with an external unit and OV module. Just remember, everything I say could be wrong - or right? Regards, Bob Lee KR2 N52BL 91% done only 63% to go! --------------------------------- Brings words and photos together (easily) with ________________________________ Message 5 _____________________________________ Time: 01:25:23 PM PST US Subject: Re: AeroElectric-List: Re: Over-voltage event w/ IR alternator From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" Hello George, A couple of questions: What causes the failed IR overvoltage event to max-out at 17V (or 18V)? Is it loads and battery? Or is the field current limited somehow. It seems that we discussed that a short between Vb and the field (through the main transistor, or otherwise) would cause cause an OV event similar to what was described - open loop output, controlled by RPM, and load - the battery being the primary load. Mr Lee didn't mention whether he experimented with eliminating loads, and revving the engine to a higher RPM (I wouldn't have tried that on my daily driver). But it seems that you are suggesting that even had he done that, 17V would have been the peak voltage seen on the bus. Am I reading you right? How long can we predict that we can leave a typical 17Ah AGM battery connected to 17V, and have it act as a system filter? Is there any risk of fire associated with long term (admittedly, unquantified) operation in such a manner? Asked another way, what's the charge rate on the battery when pumped to 17V? I suppose your suggestion to include a b-lead disconnect of some sort (breaker, in your case) addresses this issue. As long as the pilot registers that the bus voltage is significantly out of limits. Without intending to put words into Bob (Nuckolls)'s mouth, I believe he has said that he can't recommend IR alternators in the context of designing an electrical system with certificated-like behavior. Not an all-out condemnation of these alternators as a whole. I believe he has, on several occasions, recognized the advantages of these low-cost devices. Regards, Matt- > --> AeroElectric-List message posted by: > > Mr. Bob Lee > > Congratulation you had an overvoltage. You saw > that it limited the voltage to 18 volts max. I > think your volt meter is off and it was likely more > like 17 volts, but that is what the ND alternators > do. Their secondary voltage control limit is either > 16v or 17v on some models. Not sure about a > Ford alternator, but all I-VR alternators (really the > only ones made now a day) use similar IC chip > control in the VR and OV limit of 17v max. > > Even though you had an overvoltage you had some > control and never exceeded 18 volts (17 volts?). > > Thanks for an excellent factual description with > out sensational emotional and prejudicial > comments. Yes an I-VR can have an OV but not the > wild runaway that gets spread around like brown > stinky stuff. Although OV is rare in the first place, > this is typical overvoltage when it does happen. > > Bob and some dislike the I-VR because there is one > transistor that controls the field. If that transistor > failed (single point failure) it could in THEORY cause > a high uncontrolled OV condition. NO one has proved > this has EVER happened as they say. By prove I > mean took a claimed runaway VR and determined the > cause was this single point failure. Its RARE indeed. > > In practice the field transistor is bullet proof. > > Cooling air adds to the reliability of that or any transistor. > > Don't install a I-VR like a E-VR they are differnt by design. > > That is my only point I have tried to make in a > year of fighting the anecdotal comments Bob and > other's make. NO OFFENSE TO BOB. I agree the > E-VR has MORE control or should say more DIRECT > control of the fundamental thing that controls > output, the field wire. THAT IS AN ADVANTAGE. > > (SEE I SAID IT, BUT THAT does not make I-VR bad.) > > However let's be real. I-VR are super reliable as > is. Failures are rare and tend to be LOW voltage > or NO voltage events. When there is a spike above > the normal set voltage its a controllable event > by adding load. > > Example in point: F150 Ford truck, IF YOU HAVE a > pull-able CB in your FORD truck for the alternator > output (b-lead), you would just pull the CB if the > voltage was too high. Done deal. No need for extra > protection or crow bars. > > HOWEVER I KNOW BOB'S philosophy that he likes > automatic control. OK that is cool. However that > comes at the expense of weight, complexity and > potential nuisance trips that can damage a good > alternator. > > BOB contradicts himself, saying don't use an I-VR at all? > > OK great advice, but a problem? > > NO ONE makes cheap off the shelf E-VR alternators? > > Why spend++$600 for B&C or GUT a perfectly good I-VR? > > Bottom line, Lee's alternator not only indicated > the OV failure, which shows the value of using the > warning light, the voltage never exceeded 18v (I > think you volt gauge is off by a volt). WHAT IS > WRONG WITH THAT? Most avionics can take anywhere > from 10-30 volts all day with out fail and even a > spike up to 60v for very short durations. > > HERE HERE Mr. Lee!!!!! > > Well done. I am putting you in my email post HALL > OF FAME. I agree with all you points except point > 6, your conclusion, but than its not that point 6 > is incorrect. I can't fault anything you said. I > just don't think its necessarily a needed. > > Of your 6 points I summit the following comments: > > 1) The alternator defaults to 18v (17v?) by > design and typical. It is also NOT > indicative of the claim that the field has > gone crazy. There is a fault and it has lost > some control, but it is NOT out of control. > > 2) One event does not make a case, but your > experience is typical. In the rare cases of > OV (anything over 14.5v). > > > 3) Check list are great > > > 4) Z-13 would but so would reach over and > pulling a CB on the B-lead. I am not sure > turning the IGN "signal" to tell the VR to > go to sleep will work every time. Bob says > he does not recommend I-VR at all any more > any way, so if you are a disciple of his > doctrine the solution is obvious. I have no > issue with that. > > > 5) I think it is worth the risk of good debate. > > > 6) I am glad for you all the best. What ever > makes you sleep at night. By the way Ford > alternators have a bad service history > according to the NHTSA (Nits-a) (National > Highway Traffic Safety Administration). ND > alternators are as prolific and have a > spotless record in regards to consumer > complain, service bulletins and recalls. > > > My points are: > > > a) use the warning light; it is a fault light > not just a no charge light. If you don't use > the warning light, have something to > indicate a charge fault (hi/lo volts). > > > b) Do not turn the alternator on and off under > load. > > > c) Wire it (the ND alternator Van sells) just > like I show below. Which is a copy of how it > works in the Suzuki Samurai it was designed > for with one addition for aircraft use, the > 50-60 amp pull-able CB in the panel. > > d) If you want an I-VR and an OV relay and crow > bar, that is fine but you would be better > off going to an external VR if you can't > live with the I-VR as is, which is Bob Lee's > conclusion. I can't fault you for that. DO > what makes you happy. > > > http://img116.imageshack.us/my.php?image=altwiring5cm.jpg > > A modified Toyota diagram. > > http://img110.imageshack.us/my.php?image=toyota7gf.jpg > > > Flame Suit on. BTW please actually read what I > wrote first. I said external VR's are better in > that you have direct access to the field wire. I > also said I agree with Bob N and Bob L and > understand the desire to either use an OV > module/relay on an I-VR or use an E-VR. > > I AGREE. Back off. > > The only point I need to make is OV events with I- > VR's are rare, which Bob Lee made for me. I also need > to point out the SO CALLED overvoltage event was a > NON EVENT. In a car or plane it does little to > nothing since most devices can live on 17volts (or > even 18 volts as Bob Lee said, which I think is a > little high). AT LEAST this event was well > document and valid case to evaluate and its impact > on aircraft operations. Obviously Mr. Lee in his > F150 could just pull over and CRASH LAND on the > shoulder of the road. In a plane pulling over and > parking on a cloud is not possible. However that > is what a battery is for. > > Sincerely George Nomex flame suit on. > > > From: > Subject: Over-voltage event w/ IR alternator > Message posted by: > > Yesterday morning on the way to church I noticed > the alternator idiot Light come on. A quick check > of the volt meter indicated 18 volts. I was > Driving my son's 1990 Ford F-150 with an IR > alternator. It took me about Thirty seconds to > figure out what to do. There was not enough time > left Before church to make a forced landing so I > kept flying. I started turning on anything > electrical to absorb the extra electrons that were > smashing the battery. When I remembered the off > road driving lights my son recently installed and > turned them on I was down to 13 volts. The > voltage would vary with RPM and as long as I kept > everything on and the RPM below 1500 I could keep > the voltage under 14 volts. As the truck > accelerated away from a stop and the transmission > was in lower gears the idiot light would come on > each time the voltage was above 16 volts which > happened around 2000 RPM. Once in high gear the > RPM would settle around 1200 and the voltage would > be around 13 volts. > > In thirty years of driving I would guess that I > have had five or six alternator failures. This is > the first time it has been a high voltage failure. > All of the other times it has been low output > failures. > > Conclusions: > > > 1. some IR alternators out there will detect an > overvoltage event (turn on the idiot light) and > yet do nothing about it (continue to produce 18 > volts). > > 2. one event does not make conclusive science > > 3. a check list for OV events would have solved > this problem quicker. I need a plan for low > frequency failures with simple solutions. > > 4. z-13 would have handled this problem in my > airplane as the main alternator would have tripped > the OV module; the low voltage tone in my > earphones would alert me to turn on the standby > alternator and flight would have continued to > destination. > > 5. what I learned from conclusions 1, 3, and 4 > is worth the risk of starting another IR > alternator e-mail flood. > > 6. I'm glad I removed the IR regulator from my > plane's alternator And replaced it with an > external unit and OV module. > > Just remember, everything I say could be wrong - or right? > Regards, > Bob Lee > KR2 N52BL > 91% done only 63% to go! > > > --------------------------------- > Brings words and photos together (easily) with > > ________________________________ Message 6 _____________________________________ Time: 01:27:34 PM PST US From: "Randy & Linda Nelson" Subject: Re: AeroElectric-List: Strobe power supplies was Wiring issues --> AeroElectric-List message posted by: "Randy & Linda Nelson" Ok My power supply is Whelen A413a 7 amps Can use either 1,2,3,4 lights are 25 +25 joules or 12 joules or 25 +12 any combination depending if alternate or simultaneous. Any thoughts on the wiring? Or the dimmer stuff? I would like to start wiring my panel but am waiting on these 2 issues. Thanks -------Original Message------- From: Charlie Kuss Subject: Re: AeroElectric-List: Strobe power supplies was Wiring issues --> AeroElectric-List message posted by: Charlie Kuss You might want to consult your Whelen manual regarding using this power pack for 3 or 4 strobe heads. What is your power supply model? Most Whelen and Nova power supplies only supply rated power to HALF the number of heads. Most units only supply half power when using more than half the maximum number of strobe heads. My Nova 904 can run up to 6 heads. However, this means that each capacitor must power 2 heads rather than 1. This cuts the charging time (and therefore the power output) for each head, in half. This could become an issue when your DAR makes his/her inspection. Charlie Kuss >--> AeroElectric-List message posted by: "rlnelson5" > >Hello > Redoing my lower dash panel. > > 1 I have a Whalen strobe powerpack that can handle either 1,2,3 > or 4 strobes. It is 14v 7a unit . I have 2 wingtip , 1 tail and 1 > red strobe/ beacon. > > My question is if I could use a [ 2-10 ?] switch to control this > strobe power unit and have the red beacon turn on the middle switch > position and then add the other 3 strobes at the top switch position? > If that would not do it is there some other arrangment to do it? > >2 I have the B + C instrament lighting dimmer setup . > I have Inst. lights, couple of post lights Radio lights ,Lower > dash panel lights , and 2 over the shoulder lights. I have a cabin > ovhd light as well. > > I am using Fiber light units on most instraments and on the lower > dash. The lower dash units are a long fiber optic strip that has > lettering on them to label the lower dash panel items. > > How should I handle this whole setup? > I only have one dimmer pot . >Do I need some type of rotary switch? > Regular switches or wire the ovhd to a seperate switch? ? wire > them all together? > >Any ideas would be helfull > > thanks l > > >Read this topic online here: > >http://forums.matronics.com/viewtopic.php?p=3D11546#11546 > > ________________________________ Message 7 _____________________________________ Time: 03:18:02 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Re: Over-voltage event w/ IR alternator --> AeroElectric-List message posted by: Brian Lloyd gmcjetpilot@yahoo.com wrote: > Bob and some dislike the I-VR because there is one > transistor that controls the field. If that transistor > failed (single point failure) it could in THEORY cause > a high uncontrolled OV condition. NO one has proved > this has EVER happened as they say. By prove I > mean took a claimed runaway VR and determined the > cause was this single point failure. Its RARE indeed. Failure of the pass transistor in internally regulated or externally regulated alternators and generators is rare but it does happen. Bob is working on an OV protection circuit for the Nanchang CJ6A for just this reason. The pass transistor in the VR shorts and turns the generator on hard. (Late-model transistorized regulator, not the old electromechanical regulator.) In one case it caused the battery to catch fire. In another case the battery exploded causing substantial damage to the aircraft. This is a dangerous failure that can result in the destruction of the aircraft in flight if it happens. It deserves attention. > In practice the field transistor is bullet proof. Uh, no, that is not quite true. It is a transistor. It can fail. And when it fails, it can fail shorted leading to an OV situation. > 1) The alternator defaults to 18v (17v?) by > design and typical. It is also NOT > indicative of the claim that the field has > gone crazy. Crazy? Not a lot of useful information in that description. If you mean that the pass transistor has shorted and turned the field on hard leading to runaway high-voltage output, then, yes, that is the problem. > There is a fault and it has lost > some control, but it is NOT out of control. I happen to think you are wrong but humor me. This is easy enough to figure out if you can get to the field winding. Throw a 'scope (something we idiot technicians know how to use) on the field and look for the field being turned on and off rapidly (PWM control). If it is always on, the pass transistor in the VR is failed shorted. > 2) One event does not make a case, but your > experience is typical. In the rare cases of > OV (anything over 14.5v). If it happens once, it will happen again. They can fail and when they do, they will do serious damage to the battery and possibly the avionics. Transistors do fail. That they are inside or outside the body of the alternator does not change this fact. Brian Lloyd brian-yak@lloyd.com ________________________________ Message 8 _____________________________________ Time: 03:48:51 PM PST US From: "Scott" Subject: AeroElectric-List: Z13-8 how to energize standby contactor? --> 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. Thanks! Scott. ________________________________ Message 9 _____________________________________ Time: 03:56:37 PM PST US From: "Scott" Subject: AeroElectric-List: Z31-B Ground power disconnect? --> AeroElectric-List message posted by: "Scott" Reviewing the diagram of the "piper" style ground power plug in Z-31B it appears that once external power is applied, the contactor would stay energized forever (at least until the battery was killed) since the engergizing current would flow backward through the contactor and through the solenoid coil. Is there a key point I'm missing or is an interrupt switch of some kind called for? Thanks! ________________________________ Message 10 ____________________________________ Time: 04:03:40 PM PST US From: "Scott" Subject: AeroElectric-List: Z-13/8 Bad if both alternators on at once? --> AeroElectric-List message posted by: "Scott" Would it be "bad" if the main alternator was still running and the standby alternator were engaged? My assumption is that which ever alternator's regulator had the higher set point would max itself out (assuming a high enough load) and the other alternator would pick up the rest (or idle) with no ill effect on the system overall. Is this true, or are there issues I'm missing like dynamic circuit response causing some kind of feedback or the smaller SD8 burning itself up? A related question: If the load is greater than the SD-8 can support is there any consequence other than the battery supplying the extra required current? For instance if I flip on the battery master and run landing lights or pitot heat or something. Thanks again! Scott. ________________________________ Message 11 ____________________________________ Time: 04:03:41 PM PST US From: "Scott" Subject: AeroElectric-List: Low Voltage Warn on E-Bus instead of Main? --> AeroElectric-List message posted by: "Scott" The Z13-8 diagram shows the low voltage warning light connected to the main bus. It seems to me like connecting it to the E-bus would be slightly more useful. In that configuration, it should illuminate if the main alt drops offline UNTIL the standby alt is engaged. At that point it stop indicating unless/until the load exceeded the output capabiliy of the SD-8 standby alternator. In that way it would essentially act as a "battery discharge" warning (with the inference that if the voltage is below alternator operating range, then the battery is discharging -- if only through the low voltage warning circuit!) BTW, what is the current draw of the Low Voltage Warning circuit? I presume it's very small and driven mostly by the light/LED used. Does anyone see a problem with this configuration? Does it miss a design consideration that motivated it's original placement? ________________________________ Message 12 ____________________________________ Time: 04:44:51 PM PST US From: Dan Brown Subject: Re: AeroElectric-List: Re: Over-voltage event w/ IR alternator --> AeroElectric-List message posted by: Dan Brown -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 gmcjetpilot@yahoo.com wrote: > Congratulation you had an overvoltage. You saw > that it limited the voltage to 18 volts max. I Since the range of the voltmeter in question only extended to 18 volts, it doesn't seem that we can confidently say what the voltage was, only that it was at least 18 volts (or at least whatever voltage causes the instrument to register 18 volts). The accuracy of the gauge could be determined easily enough by cross-checking using a DVM of known accuracy, so long as it was connected to the same place that the panel meter uses--but that's really a side issue. As the scenario was described, the voltmeter was pegged at 18 volts--you can't say from that that the resulting voltage was 18 max; it's more like 18 min. - -- Dan Brown, KE6MKS, dan@familybrown.org "Since all the world is but a story, it were well for thee to buy the more enduring story rather than the story that is less enduring." -- The Judgment of St. Colum Cille -----BEGIN PGP SIGNATURE----- Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFD8noGyQGUivXxtkERAsXeAKCsDjTY7UcQLFkZPpAiKGuqebOlVwCgolaS 9/+GcqzX2TnagvYi+LL13vc=r/Qc -----END PGP SIGNATURE----- ________________________________ Message 13 ____________________________________ Time: 04:59:32 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Over-voltage event w/ IR alternator --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 02:20 PM 2/14/2006 -0700, you wrote: >--> AeroElectric-List message posted by: "Matt Prather" > >Hello George, > >A couple of questions: > >What causes the failed IR overvoltage event to max-out at 17V (or 18V)? >Is it loads and battery? Yes, recall the power system dynamics article I started last spring: http://www.aeroelectric.com/articles/Crowbar_OV_Protection/DC_Power_System_Dynamics_C.pdf Starting on page 6 we explore the battery's ability to stand of the output of a runaway alternator . . . > Or is the field current limited somehow. It >seems that we discussed that a short between Vb and the field (through the >main transistor, or otherwise) would cause cause an OV event similar to >what was described - open loop output, controlled by RPM, and load - the >battery being the primary load. Mr Lee didn't mention whether he >experimented with eliminating loads, and revving the engine to a higher >RPM (I wouldn't have tried that on my daily driver). But it seems that >you are suggesting that even had he done that, 17V would have been the >peak voltage seen on the bus. Am I reading you right? > >How long can we predict that we can leave a typical 17Ah AGM battery >connected to 17V, and have it act as a system filter? Depends on the size of the battery, its construction and it's station in service life. The newer the battery, and assuming it's an RG battery, it will hold a 60A alternator to something under 20 volts for some period of time. I'd guess maybe a minute or more. > Is there any risk >of fire associated with long term (admittedly, unquantified) operation in >such a manner? Yes but slight. Remember this Odyssey battery we got from a Lister who had suffered an ov condition? See pictures at: http://www.aeroelectric.com/Pictures/Battery/Odyssey_OV/Odyssey_OV_1.jpg But the risk is non-existent if you have some form of ov warning, if only a light. You have some period of time from onset of ov condition until things start coming unglued. >Asked another way, what's the charge rate on the battery >when pumped to 17V? I suppose your suggestion to include a b-lead >disconnect of some sort (breaker, in your case) addresses this issue. As >long as the pilot registers that the bus voltage is significantly out of >limits. > >Without intending to put words into Bob (Nuckolls)'s mouth, I believe he >has said that he can't recommend IR alternators in the context of >designing an electrical system with certificated-like behavior. Not an >all-out condemnation of these alternators as a whole. I believe he has, >on several occasions, recognized the advantages of these low-cost devices. Back in December, I posted this response: >Bob, > >Any recent updates on the "internally regulated alternator"? > >I know that you were not recommending it's use on an "all electric >airplane with dual electronic ignition", which is the configuration of the >plane I am building. Not at all. The modern internally regulated alternator is a great piece of hardware that offers excellent value over most 60's certified alternators flying today. Your choice of alternators has nothing to do with whether or not you have electronic ignition, EFIS, or any other modern feature. Depending on WHICH IR alternator you choose, you may not have 100%, absolute control over it's output which does not satisfy traditional design goals. Further, depending on WHICH IR alternator you choose, you may not be able to add a convenient form of OV protection which is also a traditional design goal. Finally, depending on WHICH IR alternator you choose, the act of turning it on and OFF at inopportune times may damage the alternator's regulator. Having offered this, there are thousands of OBAM aircraft flying wherein the builder has not included these points in satisfaction of his own design goals either because he has considered them insignificant or doesn't understand them well enough to make a well considered decision. None-the-less, a vast majority of these aircraft ARE flying trouble free. However, from time to time, we're made aware of installations where the builder wishes he had considered and adopted the traditional design goals. It's a small percentage to be sure . . . but then catastrophic runaway failures in the certified ships also constitutes a small percentage of all failures. Bottom line is that we will be able to offer a means by which any internally regulated alternator can be integrated into your airplane under the traditional design goals. In the mean time, drive on with whatever installation instructions come with your alternator of choice knowing that modifying the system will be easy and inexpensive at a later time. I've been trying to get the next few pages of "Understanding Alternators" http://www.aeroelectric.com/articles/alternators/UA/Alternators_1.html published but things are really busy around here this time of year. --------------------------------------- I've been working on the "Understanding Alternators" article and plan to combine it with the DC Power System Dynamics article. Bob . . . ________________________________ Message 14 ____________________________________ Time: 05:28:44 PM PST US From: Charlie Kuss Subject: Re: AeroElectric-List: Strobe power supplies was Wiring issues Cc: aeroelectric-list@matronics.com --> AeroElectric-List message posted by: Charlie Kuss Nelson, Did you get an installation manual with this power supply? I ask, because the A413A is an obsolete model. It has been superceded by the model HDACF. See http://www.whelen.com/aviation/catalog/Power%20Supply%20Replacement.pdf Whelen's installation manual can be found here http://www.whelen.com/aviation/Avserman.pdf This unit will not meet the current light requirements, as even in alternating mode, it only supplies 25 joules. Current requirement is for approximately 40 joules. Most newer Whelen or Nova units produce 42 joules of light energy. Running 3 or more strobe heads simultaneously will reduce the output to only 12.5 joules. Can you email me an electronic copy of your manual, if you have one? Charlie Kuss >--> AeroElectric-List message posted by: "Randy & Linda Nelson" > > >Ok My power supply is Whelen A413a 7 amps Can use either 1,2,3,4 lights >are 25 +25 joules or 12 joules or 25 +12 any combination depending if >alternate or simultaneous. Any thoughts on the wiring? Or the dimmer >stuff? I would like to start wiring my panel but am waiting on these 2 >issues. Thanks > >-------Original Message------- > >From: Charlie Kuss >Date: 02/13/06 08:05:16 >To: aeroelectric-list@matronics.com >Subject: Re: AeroElectric-List: Strobe power supplies was Wiring issues > >--> AeroElectric-List message posted by: Charlie Kuss net> > >You might want to consult your Whelen manual regarding using this >power pack for 3 or 4 strobe heads. What is your power supply model? >Most Whelen and Nova power supplies only supply rated power to HALF >the number of heads. Most units only supply half power when using >more than half the maximum number of strobe heads. My Nova 904 can >run up to 6 heads. However, this means that each capacitor must power >2 heads rather than 1. This cuts the charging time (and therefore the >power output) for each head, in half. > This could become an issue when your DAR makes his/her inspection. >Charlie Kuss > > >--> AeroElectric-List message posted by: "rlnelson5" com> > > > >Hello > > Redoing my lower dash panel. > > > > 1 I have a Whalen strobe powerpack that can handle either 1,2,3 > > or 4 strobes. It is 14v 7a unit . I have 2 wingtip , 1 tail and 1 > > red strobe/ beacon. > > > > My question is if I could use a [ 2-10 ?] switch to control this > > strobe power unit and have the red beacon turn on the middle switch > > position and then add the other 3 strobes at the top switch position? > > If that would not do it is there some other arrangment to do it? > > > >2 I have the B + C instrament lighting dimmer setup . > > I have Inst. lights, couple of post lights Radio lights ,Lower > > dash panel lights , and 2 over the shoulder lights. I have a cabin > > ovhd light as well. > > > > I am using Fiber light units on most instraments and on the lower > > dash. The lower dash units are a long fiber optic strip that has > > lettering on them to label the lower dash panel items. > > > > How should I handle this whole setup? > > I only have one dimmer pot . > >Do I need some type of rotary switch? > > Regular switches or wire the ovhd to a seperate switch? ? wire > > them all together? > > > >Any ideas would be helfull > > > > thanks l > > > > > > > > > >Read this topic online here: > > > >http://forums.matronics.com/viewtopic.php?p=3D11546#11546 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________ Message 15 ____________________________________ Time: 05:30:59 PM PST US From: Ken Subject: Re: AeroElectric-List: Re: Over-voltage event w/ IR alternator --> AeroElectric-List message posted by: Ken Exactly what I was thinking Dan. Even though the idiot light came on, without further info or testing of the alternator I see no reason to assume that there was secondary OV protection operating in this example. Maybe it was, maybe it wasn't. Ken Dan Brown wrote: >--> AeroElectric-List message posted by: Dan Brown > >-----BEGIN PGP SIGNED MESSAGE----- >Hash: SHA1 > >gmcjetpilot@yahoo.com wrote: > > > >>Congratulation you had an overvoltage. You saw >>that it limited the voltage to 18 volts max. I >> >> > > Since the range of the voltmeter in question only extended to 18 volts, >it doesn't seem that we can confidently say what the voltage was, only >that it was at least 18 volts (or at least whatever voltage causes the >instrument to register 18 volts). The accuracy of the gauge could be >determined easily enough by cross-checking using a DVM of known >accuracy, so long as it was connected to the same place that the panel >meter uses--but that's really a side issue. As the scenario was >described, the voltmeter was pegged at 18 volts--you can't say from that >that the resulting voltage was 18 max; it's more like 18 min. > >- -- >Dan Brown, KE6MKS, dan@familybrown.org > > ________________________________ Message 16 ____________________________________ Time: 10:46:54 PM PST US From: "Chris & Kellie Hand" Subject: AeroElectric-List: instrument wiring --> AeroElectric-List message posted by: "Chris & Kellie Hand" I'm working on installing wiring and panel stuff in my RV-6A. The Van's fuel gage and ammeter installation instructions say to use 18 AWG wire for the power, ground, and sensor wires on the fuel gages and for the power and ground wire on the ammeter. I didn't read that until after wiring up with 22 AWG as I didn't think the current draw was significant enough to warrant anything bigger - based this on an estimate of ~0.4 amps max per instrument from reference material I looked at (yes, I looked through several books but didn't read the instructions that came with the instruments....). Am I that far out on my load estimates? Anybody think 18 AWG is really necessary for powering these instruments? I'm wiring these independently, not daisy chaining them as shown in the Van's drawings. Thanks for any feedback, Chris Hand RV-6A, finishing stages ________________________________ Message 17 ____________________________________ Time: 10:50:48 PM PST US From: "Chris & Kellie Hand" Subject: AeroElectric-List: dimmer ckt from Van's --> AeroElectric-List message posted by: "Chris & Kellie Hand" I hooked up my instrument lights to the Van's dimmer ckt I installed and powered things up. Power distribution is working and I have battery voltage at the +12V terminal screw on the dimmer board. Also show good ground on the dimmer board's ground terminal screw. Potentiometer is working properly and connected to the right terminals on the board. Output I'm getting at the Load terminal on the dimmer board varies from 0 to about 6 mV rather than the expected 2.5 V up to battery voltage. The dimmer ckt is new out of the box, but I bought it well over a year ago and didn't test it prior to now. Has anybody experienced similar issues with the Van's board, and are there any suggestions on how to fix it without having to buy a new one? If I give up on the dimmer ckt from Van's, I need to find something else with a poteniometer/dimmer knob the same size or larger since I already have the current one installed in the panel. Thanks for any help or advice you can give me. Chris Hand RV-6A, finishing stages