---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 12/10/15: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:57 AM - Revisiting Ground Power Adapter: Modern Chargers (rampil) 2. 08:18 AM - Re: Circuit breaker question (Robert L. Nuckolls, III) 3. 08:36 AM - Re: Revisiting Ground Power Adapter: Modern Chargers (Robert L. Nuckolls, III) 4. 10:31 AM - Re: Circuit breaker question (Paul Millner) 5. 12:22 PM - Re: Circuit breaker question (Justin Jones) 6. 02:13 PM - Re: Circuit breaker question (Charlie England) 7. 04:19 PM - ADS-B antenna location (jrevens) 8. 06:39 PM - Re: Troubleshooting radio whine/noise on C essna 182P (sacha) 9. 06:50 PM - Re: Circuit breaker question (Robert L. Nuckolls, III) 10. 06:51 PM - Re: Circuit breaker question (Robert L. Nuckolls, III) 11. 06:57 PM - Re: ADS-B antenna location (David Lloyd) 12. 11:17 PM - Re: ADS-B antenna location (Rob Turk) ________________________________ Message 1 _____________________________________ Time: 06:57:39 AM PST US Subject: AeroElectric-List: Revisiting Ground Power Adapter: Modern Chargers From: "rampil" Greetings All! I recently updated my Europa/Rotax to move my batteries to the back of the airframe from the firewall. Since the batteries are now inaccessible, I decided to install a formal charging port on the fuselage. Starting with Bob's original design, I used the circuit design, changing only the receptacle to an Anderson Power Products 175 AH (I just couldn't justify the weight of the antique, massive Piper receptacle). The System works well when connected to an external 12V truck battery, or when connected to an old fashioned (20-30 year old) aircraft shop charger. However, when driving the airframe battery with a modern, computer- controlled charger, the charge port contactor relay chatters (oscillates open-closed) at 3-5 Hz. If I modify the Nuckoll's circuit to remove the kickback diode on the contactor (1N4001), the chatter stops and circuit performs as expected. I have yet to put a scope on the circuit, but the 12 Henries of reactance I estimated on the White-Rogers Type 71 coil seems to interact badly with the voltage sensing feature of "Smart" chargers. Any Thoughts? Ira -------- Ira N224XS Read this topic online here: http://forums.matronics.com/viewtopic.php?p=450860#450860 ________________________________ Message 2 _____________________________________ Time: 08:18:33 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Circuit breaker question At 06:02 PM 12/7/2015, you wrote: >Jones > >Hangar talk with a neighbor. He is designing a >circuit using 4awg wire for his alternator. He >asked me if he could use 2 - 50A circuit >breakers wired in Parallel for this purpose >instead of a single 100A breaker. Chapter 11 in >AC 43 says to use a 100A breaker or a 70A fuse >for 4AWG wire. I suggested the use of a 70A ANL >fuse, but wasn=99t sure what the answer is to the CB question he had. Few OEMs (if any) in the certified iron business use circuit breakers in the alternator b-lead. At Beech, current limiters on the firewall have protected the b-lead for 30 or more years. Check out the products on this webpage http://tinyurl.com/by5qnop These are miniature, high current fuses and matching holders widely available through automotive and mobile sound system dealers. You can find all sizes along with mounting bases on ebay. http://tinyurl.com/jn9k9nu One caveat . . . AVOID the fuse holders that grip the fat-wires with mash-screws. You want a holder with captive, male studs which are used to place the fuse-tab into intimate contact with the ring-terminal on the end of your b-lead wiring. A holder like this one http://tinyurl.com/54fk can be 'modified' to a satisfactory aviation fuse holder by discarding the mash-screws and dropping your ring terminals over the fuse attach screws. Consider making your own fuse holder . . . A block carved from phenolic, delrin, micarta or other high temp, machinable plastic. http://tinyurl.com/jdatd3e These parts combined with some 10-32 stainless steel screws, nuts and washers from a hardware store will produce a robust alternative to purchased/modified fuse holders. Pick a MIDI fuse rating at or just above the alternator rating. If the guy wants to use a breaker, the rating should be 20-50% LARGER than the alternator output. Finally, DO NOT parallel breakers. Bob . . . ________________________________ Message 3 _____________________________________ Time: 08:36:12 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Revisiting Ground Power Adapter: Modern Chargers However, when driving the airframe battery with a modern, computer- controlled charger, the charge port contactor relay chatters (oscillates open-closed) at 3-5 Hz. If I modify the Nuckoll's circuit to remove the kickback diode on the contactor (1N4001), the chatter stops and circuit performs as expected. I have yet to put a scope on the circuit, but the 12 Henries of reactance I estimated on the White-Rogers Type 71 coil seems to interact badly with the voltage sensing feature of "Smart" chargers. May very well be . . . the current bevy of 'smart chargers' seem to have many and varied minds of their own. I did some tests on a "carbon foam" SVLA battery for Beech a few years ago. This 100AH battery would not charge in a timely manner with any of my 'standard' chargers. I purchased a new Schumacher charger rated at 25A. Here's a voltage plot of the charger's output for recovering from a deep discharge Emacs! Batteries are probably the ultimate integrators of 'rough' charging profiles but as you've noted, 'foreign' devices in the circuit may produce unexpected behaviors. Bob . . . ________________________________ Message 4 _____________________________________ Time: 10:31:55 AM PST US Subject: Re: AeroElectric-List: Circuit breaker question From: Paul Millner On 12/10/2015 8:16 AM, Robert L. Nuckolls, III wrote: > Few OEMs (if any) in the certified iron business > use circuit breakers in the alternator b-lead. Hey Bob! You're overlooking our friends at Cessna, responsible for almost half the single engine land aircraft out there! From the first installation of alternators through, I believe, today, they put a breaker at the main bus where the alternator power enters... in my '76 Cardinal (12 volt) that's a 60 amp beast which is hard to come by, and subject of several service bulletins over the years (aluminum bus heating causing false tripping, etc.) Paul ________________________________ Message 5 _____________________________________ Time: 12:22:43 PM PST US From: Justin Jones Subject: Re: AeroElectric-List: Circuit breaker question Convinced him to go with ANL fuses. Where is the best place to locate them? C lose to the alternator or close to the battery? Bob's Z diagrams show them near the battery. If protecting against a short, w ouldn't the battery end of the b lead be best? Or are we simply protecting f rom an over amperage condition? Justin > On Dec 10, 2015, at 07:16, Robert L. Nuckolls, III wrote: > > At 06:02 PM 12/7/2015, you wrote: ring.com> >> >> Hangar talk with a neighbor. He is designing a circuit using 4awg wire fo r his alternator. He asked me if he could use 2 - 50A circuit breakers wire d in Parallel for this purpose instead of a single 100A breaker. Chapter 11 i n AC 43 says to use a 100A breaker or a 70A fuse for 4AWG wire. I suggested t he use of a 70A ANL fuse, but wasn=99t sure what the answer is to the C B question he had. > > Few OEMs (if any) in the certified iron business > use circuit breakers in the alternator b-lead. > At Beech, current limiters on the firewall have > protected the b-lead for 30 or more years. > > Check out the products on this webpage > > http://tinyurl.com/by5qnop > > These are miniature, high current fuses > and matching holders widely available through > automotive and mobile sound system dealers. > You can find all sizes along with mounting > bases on ebay. > > http://tinyurl.com/jn9k9nu > > One caveat . . . AVOID the fuse holders > that grip the fat-wires with mash-screws. > You want a holder with captive, male studs > which are used to place the fuse-tab into > intimate contact with the ring-terminal on > the end of your b-lead wiring. > > A holder like this one > > http://tinyurl.com/54fk > > can be 'modified' to a satisfactory aviation > fuse holder by discarding the mash-screws > and dropping your ring terminals over the > fuse attach screws. > > Consider making your own fuse holder . . . > A block carved from phenolic, delrin, micarta > or other high temp, machinable plastic. > > http://tinyurl.com/jdatd3e > > These parts combined with some 10-32 stainless > steel screws, nuts and washers from a hardware > store will produce a robust alternative > to purchased/modified fuse holders. > > Pick a MIDI fuse rating at or just above > the alternator rating. If the guy wants to > use a breaker, the rating should be 20-50% > LARGER than the alternator output. Finally, > DO NOT parallel breakers. > > > Bob . . . ________________________________ Message 6 _____________________________________ Time: 02:13:55 PM PST US Subject: Re: AeroElectric-List: Circuit breaker question From: Charlie England On December 10, 2015 3:21:06 PM EST, Justin Jones wrote: >Convinced him to go with ANL fuses. Where is the best place to locate >them? Close to the alternator or close to the battery? > >Bob's Z diagrams show them near the battery. If protecting against a >short, wouldn't the battery end of the b lead be best? Or are we simply >protecting from an over amperage condition? > >Justin > > > >> On Dec 10, 2015, at 07:16, Robert L. Nuckolls, III > wrote: >> >> At 06:02 PM 12/7/2015, you wrote: > >>> >>> Hangar talk with a neighbor. He is designing a circuit using 4awg >wire for his alternator. He asked me if he could use 2 - 50A circuit >breakers wired in Parallel for this purpose instead of a single 100A >breaker. Chapter 11 in AC 43 says to use a 100A breaker or a 70A fuse >for 4AWG wire. I suggested the use of a 70A ANL fuse, but wasnt sure >what the answer is to the CB question he had. >> >> Few OEMs (if any) in the certified iron business >> use circuit breakers in the alternator b-lead. >> At Beech, current limiters on the firewall have >> protected the b-lead for 30 or more years. >> >> Check out the products on this webpage >> >> http://tinyurl.com/by5qnop >> >> These are miniature, high current fuses >> and matching holders widely available through >> automotive and mobile sound system dealers. >> You can find all sizes along with mounting >> bases on ebay. >> >> http://tinyurl.com/jn9k9nu >> >> One caveat . . . AVOID the fuse holders >> that grip the fat-wires with mash-screws. >> You want a holder with captive, male studs >> which are used to place the fuse-tab into >> intimate contact with the ring-terminal on >> the end of your b-lead wiring. >> >> A holder like this one >> >> http://tinyurl.com/54fk >> >> can be 'modified' to a satisfactory aviation >> fuse holder by discarding the mash-screws >> and dropping your ring terminals over the >> fuse attach screws. >> >> Consider making your own fuse holder . . . >> A block carved from phenolic, delrin, micarta >> or other high temp, machinable plastic. >> >> http://tinyurl.com/jdatd3e >> >> These parts combined with some 10-32 stainless >> steel screws, nuts and washers from a hardware >> store will produce a robust alternative >> to purchased/modified fuse holders. >> >> Pick a MIDI fuse rating at or just above >> the alternator rating. If the guy wants to >> use a breaker, the rating should be 20-50% >> LARGER than the alternator output. Finally, >> DO NOT parallel breakers. >> >> >> Bob . . . Battery end. Battery can melt the wire; alt cannot. -- Sent from my Android device with K-9 Mail. Please excuse my brevity. ________________________________ Message 7 _____________________________________ Time: 04:19:02 PM PST US Subject: AeroElectric-List: ADS-B antenna location From: "jrevens" I stupidly did a very nice ADS-B UAT antenna installation on my new project before doing all of my homework. It is 45 inches from my transponder antenna. I just received my ADS600-EXP unit. NavWorx says that there must be a minimum of 5 feet of separation or the ADS-B unit will fail (their words). Has anyone broken this rule and had successful operation with less than 5 feet of separation? Can a closer distance actually cause damage to the unit? In this particular instance, moving the ADS-B antenna will be a difficult and messy change to have to make. Can't believe I did that. -------- John Evens Thorp T-18 N71JE (built & flying) Kitfox SS7 N27JE (building) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=450878#450878 ________________________________ Message 8 _____________________________________ Time: 06:39:55 PM PST US Subject: AeroElectric-List: Re: Troubleshooting radio whine/noise on C essna 182P From: "sacha" That's a good idea. I asked my A&P if he could do that but he said it would be a lot of work. I will see if I can devise a way. Seems like it would be a good test. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=450879#450879 ________________________________ Message 9 _____________________________________ Time: 06:50:19 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Circuit breaker question At 12:30 PM 12/10/2015, you wrote: > > >On 12/10/2015 8:16 AM, Robert L. Nuckolls, III wrote: >>Few OEMs (if any) in the certified iron business >> use circuit breakers in the alternator b-lead. > >Hey Bob! > >You're overlooking our friends at Cessna, responsible for almost >half the single engine land aircraft out there! From the first >installation of alternators through, I believe, today, they put a >breaker at the main bus where the alternator power enters... in my >'76 Cardinal (12 volt) that's a 60 amp beast which is hard to come >by, and subject of several service bulletins over the years >(aluminum bus heating causing false tripping, etc.) Yes, that's where they were when I worked there too . . . but I thought those were moved off the panel when the Lamar power distribution box went into production . . . and that's been some time ago. I'll have to check my G2 sources . . . Bob . . . ________________________________ Message 10 ____________________________________ Time: 06:51:17 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Circuit breaker question At 02:21 PM 12/10/2015, you wrote: >Convinced him to go with ANL fuses. Where is the best place to >locate them? Close to the alternator or close to the battery? > >Bob's Z diagrams show them near the battery. If protecting against a >short, wouldn't the battery end of the b lead be best? Or are we >simply protecting from an over amperage condition? Close to the battery. An alternator is physically incapable of burning its own b-lead . . . but the BATTERY is good for 1000+ amps in a fault condition. Bob . . . ________________________________ Message 11 ____________________________________ Time: 06:57:07 PM PST US From: "David Lloyd" Subject: Re: AeroElectric-List: ADS-B antenna location John, Others will answer with greater detail, but here is what you are up against. . . The transponder puts out high wattage pulse returns in answer to a radar inquiry. That pulse of power is going to hit your ADS antenna pretty hard. I don't have a clue what modern receiver solid state circuits can deal with these days but, that pulse is made up of a huge bandwidth of harmonics, etc. that typically make up/define a "pulse". My thinking is that 60" and more is needed to not cause problems. . . David ----- Original Message ----- From: "jrevens" Sent: Thursday, December 10, 2015 4:17 PM Subject: AeroElectric-List: ADS-B antenna location > > I stupidly did a very nice ADS-B UAT antenna installation on my new > project before doing all of my homework. It is 45 inches from my > transponder antenna. I just received my ADS600-EXP unit. NavWorx says > that there must be a minimum of 5 feet of separation or the ADS-B unit > will fail (their words). Has anyone broken this rule and had successful > operation with less than 5 feet of separation? Can a closer distance > actually cause damage to the unit? In this particular instance, moving the > ADS-B antenna will be a difficult and messy change to have to make. Can't > believe I did that. > > -------- > John Evens > Thorp T-18 N71JE (built & flying) > Kitfox SS7 N27JE (building) > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=450878#450878 > > > --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 12 ____________________________________ Time: 11:17:15 PM PST US Subject: Re: AeroElectric-List: ADS-B antenna location From: Rob Turk The transponder transmits a certain amount of energy. As you move away from the antenna, the energy spreads out. Only some of the transmitted energy will hit the receiving antenna and the further you move away, the less energy will be 'caught'. When too close, the amount of energy induced in the receiver antenna can overwhelm or even damage the sensitive ADS-B receiver. The attenuation between transmitter antenna and receiver antenna is called 'free space path loss'. There is a formula to calculate that loss, and here's a link that will let you play with it: https://www.pasternack.com/t-calculator-fspl.aspx Using that calculator, the difference between 45 inches and 5ft at 1GHz is less than 3dB. That is not a whole lot. A poor quality antenna cable will already give you that. That means for your situation that you can simulate the extra distance by adding a 3dB attenuator in your receiver antenna cable. The drawback is that you'll have slightly worse coverage (the signals that you want are also attenuated a bit), but should be safe. You may want to call NavWorx and ask them about this. Things also depend on the rest of your installation, such as type and output of your transponder, antenna cable type and lengths for both devices, etc. Rob On 12/11/2015 3:55 AM, David Lloyd wrote: > > > John, > > Others will answer with greater detail, but here is what you are up > against. . . > > The transponder puts out high wattage pulse returns in answer to a > radar inquiry. That pulse of power is going to hit your ADS antenna > pretty hard. I don't have a clue what modern receiver solid state > circuits can deal with these days but, that pulse is made up of a huge > bandwidth of harmonics, etc. that typically make up/define a "pulse". > My thinking is that 60" and more is needed to not cause problems. . . > David > > > ----- Original Message ----- From: "jrevens" > To: > Sent: Thursday, December 10, 2015 4:17 PM > Subject: AeroElectric-List: ADS-B antenna location > > >> >> I stupidly did a very nice ADS-B UAT antenna installation on my new >> project before doing all of my homework. It is 45 inches from my >> transponder antenna. I just received my ADS600-EXP unit. NavWorx >> says that there must be a minimum of 5 feet of separation or the >> ADS-B unit will fail (their words). Has anyone broken this rule and >> had successful operation with less than 5 feet of separation? Can a >> closer distance actually cause damage to the unit? In this particular >> instance, moving the ADS-B antenna will be a difficult and messy >> change to have to make. Can't believe I did that. >> >> -------- >> John Evens >> Thorp T-18 N71JE (built & flying) >> Kitfox SS7 N27JE (building) >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=450878#450878 >> >> >> >> >> >> >> >> >> >> > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.