---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 01/04/19: 30 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:30 AM - Re: Alternator/shunt question (supik) 2. 03:46 AM - Re: GPS Antennae (GTH) 3. 04:48 AM - Re: Re: Alternator/shunt question (Art Zemon) 4. 04:58 AM - Re: A brown-out alternative? (user9253) 5. 05:14 AM - Re: Re: Alternator/shunt question (Art Zemon) 6. 05:36 AM - Re: GPS Antennae (Robert L. Nuckolls, III) 7. 05:42 AM - Re: Re: Transponder Antenna (Robert L. Nuckolls, III) 8. 06:54 AM - Re: Re: A brown-out alternative? (Robert L. Nuckolls, III) 9. 07:34 AM - Re: Transponder Antenna (Tundra10) 10. 09:57 AM - Re: Re: Transponder Antenna (Robert L. Nuckolls, III) 11. 11:33 AM - Re: Alternator/shunt question (supik) 12. 01:28 PM - Re: Re: Alternator/shunt question (Robert L. Nuckolls, III) 13. 02:44 PM - Re: Relay sticking (Sebastien) 14. 03:35 PM - Re: Alternator/shunt question (supik) 15. 04:13 PM - Re: Re: Alternator/shunt question () 16. 04:18 PM - Re: Re: Alternator/shunt question (don van santen) 17. 04:40 PM - Re: Alternator/shunt question (supik) 18. 05:08 PM - Re: Re: Alternator/shunt question (Charlie England) 19. 06:01 PM - Re: Alternator/shunt question (supik) 20. 06:28 PM - Re: Re: Alternator/shunt question (don van santen) 21. 06:52 PM - Re: Re: Alternator/shunt question (Charlie England) 22. 07:03 PM - Re: Alternator/shunt question (supik) 23. 07:19 PM - Re: Alternator/shunt question (supik) 24. 07:47 PM - Re: Re: Alternator/shunt question (Charlie England) 25. 08:10 PM - Re: Re: Alternator/shunt question (Charlie England) 26. 08:21 PM - Re: Alternator/shunt question (supik) 27. 08:32 PM - Re: Alternator/shunt question (user9253) 28. 08:49 PM - Re: Alternator/shunt question (supik) 29. 09:10 PM - Re: Alternator/shunt question (supik) 30. 09:34 PM - Re: Re: Alternator/shunt question (Kelly McMullen) ________________________________ Message 1 _____________________________________ Time: 01:30:31 AM PST US Subject: AeroElectric-List: Re: Alternator/shunt question From: "supik" Art, at what voltage did you setup your Aux Alt? What is the max Voltage the Standby Regulator will allow? Thanks, -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486700#486700 ________________________________ Message 2 _____________________________________ Time: 03:46:01 AM PST US Subject: Re: AeroElectric-List: GPS Antennae From: GTH Le 04/01/2019 05:51, speedy11@aol.com a crit: > > But, if I mount a GPS antenna inside the airplane on a glare shield, > does the orientation matter? > Hi Stan, When installing our GPS antenna on the glareshield we did not pay any attention to the orientation. Everything has been woring great since then, even in the hangar. http://contrails.free.fr/gps_en.php Furthermore, if orientation did matter, reception would depend on the heading of the airplane, which is not desirable. Hope this helps, -- Best regards, Gilles http://contrails.free.fr http://lapierre.skunkworks.free.fr ________________________________ Message 3 _____________________________________ Time: 04:48:02 AM PST US From: Art Zemon Subject: Re: AeroElectric-List: Re: Alternator/shunt question Igor, The backup voltage regulator came preset to 13.0 volts. Per a discussion here, I am going to increase it to 13.5 volts. You might want to look at the manual for the regulator on B&C Aero's website. It is available here: http://www.bandc.aero/standbyalternatorcontroller14vhomebuilt.aspx Cheers, -- Art Z. On Fri, Jan 4, 2019 at 3:49 AM supik wrote: > > Art, at what voltage did you setup your Aux Alt? What is the max Voltage > the Standby Regulator will allow? > -- https://CheerfulCurmudgeon.com/ *"Be kind, for everyone you meet is fighting a hard battle."* ________________________________ Message 4 _____________________________________ Time: 04:58:13 AM PST US Subject: AeroElectric-List: Re: A brown-out alternative? From: "user9253" It would be an interesting experiment to see if the brownout-DC-DC converter would work without the relay. The purpose of the relay is to provide milliseconds of delay in opening the circuit after cranking the engine. When the engine starts, human reaction time for releasing the start button provides a delay. If the engine does not start, the need for a delay depends on the battery voltage. Doesn't the battery voltage start recovering within a few milliseconds after engine cranking begins? -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486703#486703 ________________________________ Message 5 _____________________________________ Time: 05:14:29 AM PST US From: Art Zemon Subject: Re: AeroElectric-List: Re: Alternator/shunt question Ernest, I used LibreOffice Draw. Here are the drawings: https://github.com/azemon/N114AC_wiring Cheers, -- Art Z. On Thu, Jan 3, 2019 at 4:12 PM Ernest Christley wrote: > How did you manage that with LibreOffice, Art? I've never been able to > get anything other than the most rudimentary drawings out of it. I'd > appreciate you sharing your source files. I would definitely use it to > improve my POH. > -- https://CheerfulCurmudgeon.com/ *"Be kind, for everyone you meet is fighting a hard battle."* ________________________________ Message 6 _____________________________________ Time: 05:36:38 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: GPS Antennae At 10:51 PM 1/3/2019, you wrote: >Do GPS antennae have an electronic front and rear? >When physically attaching an antenna to an airplane there is a >designed direction for strength and best aerodynamic airflow. >But, if I mount a GPS antenna inside the airplane on a glare shield, >does the orientation matter? > >Stan Sutterfield No . . . they are omni-directional Bob . . . ________________________________ Message 7 _____________________________________ Time: 05:42:09 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Transponder Antenna At 03:52 PM 1/3/2019, you wrote: > >One thing I find odd about the blade transponder antenna, is that >the entire body is a chunk of aluminum. There is a horizontal band >with a plastic? covering. So it seems the radiating element is >pretty shielded inside. > >It is a Dorne & Margolin DM NI 70-2 if anyone is familiar with it. That whole chunk of aluminum above the plastic insulator IS the antenna. Bob . . . ________________________________ Message 8 _____________________________________ Time: 06:54:38 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: A brown-out alternative? At 06:57 AM 1/4/2019, you wrote: > >It would be an interesting experiment to see if the brownout-DC-DC converter > would work without the relay. The purpose of the relay is to provide >milliseconds of delay in opening the circuit after cranking the engine. Yes, a delay greater than the dropout delay in the starter contactor. > When the >engine starts, human reaction time for releasing the start button provides a >delay. If the engine does not start, the need for a delay depends >on the battery >voltage. Doesn't the battery voltage start recovering within a few >milliseconds >after engine cranking begins? Usually . . . if the battery is relatively robust and in good condition. Try it without the relay. It can't do anything worse than not work. Bob . . . ________________________________ Message 9 _____________________________________ Time: 07:34:27 AM PST US Subject: AeroElectric-List: Re: Transponder Antenna From: "Tundra10" This would be easier for me to understand if the plastic insulator went all the way around. It only goes halfway, so the aluminum at the tip of the antenna is the same solid chunk of aluminum as at the base, which is connected to the shield of the cable and the aluminum skin of the aircraft. Jeff Page Dream Aircraft Tundra #10 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486708#486708 ________________________________ Message 10 ____________________________________ Time: 09:57:15 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Transponder Antenna At 09:33 AM 1/4/2019, you wrote: > >This would be easier for me to understand if the plastic insulator >went all the way around. > >It only goes halfway, so the aluminum at the tip of the antenna is >the same solid chunk of aluminum as at the base, which is connected >to the shield of the cable and the aluminum skin of the aircraft. If only one side of the blade is insulated then the antenna's feed-point is at the center of the insulated side with some form of matching not unlike a 'gamma match' on a 1/4 wave vertical. This allows the whole antenna to be formed from a single piece of metal for mechanical robustness, total ground at DC, yet presents a 50 ohm load to the transmission line. Antenna design and fabrication often seems like magic . . . looking through the myriad of patents can leave one in awe for those to have mastered the art! Just did a quick search on 'blade antennas' hoping that the antenna under discussion might pop up . . . https://tinyurl.com/ya24kfgu good luck with that! I think I've got some data on that design buried around here somewhere. If I run across the article, I'll post it. Bob . . . ________________________________ Message 11 ____________________________________ Time: 11:33:15 AM PST US Subject: AeroElectric-List: Re: Alternator/shunt question From: "supik" Art, that's my concern.. I think that's not enough Volts to charge the battery.. art(at)zemon.name wrote: > Igor, > > > The backup voltage regulator came preset to 13.0 volts. Per a discussion here, I am going to increase it to 13.5 volts. > You might want to look at the manual for the regulator on B&C Aero's website. It is available here:http://www.bandc.aero/standbyalternatorcontroller14vhomebuilt.aspx (http://www.bandc.aero/standbyalternatorcontroller14vhomebuilt.aspx) > > > Cheers, > -- Art Z. > > > On Fri, Jan 4, 2019 at 3:49 AM supik wrote: > > > > > > Art, at what voltage did you setup your Aux Alt? What is the max Voltage the Standby Regulator will allow? > > > > > > -- > https://CheerfulCurmudgeon.com/ (https://CheerfulCurmudgeon.com/)"Be kind, for everyone you meet is fighting a hard battle." -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486712#486712 ________________________________ Message 12 ____________________________________ Time: 01:28:25 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Alternator/shunt question At 01:32 PM 1/4/2019, you wrote: > >Art, that's my concern.. I think that's not enough Volts to charge >the battery.. > One does not CHARGE a battery with the standby alternator . . . you only support the bus at some level that prevents DISCHARGING the battery. The idea is to minimize loads to some level at or below what the standby alternator will deliver thus holding the battery in reserve for approach to landing Bob . . . ________________________________ Message 13 ____________________________________ Time: 02:44:48 PM PST US From: Sebastien Subject: Re: AeroElectric-List: Relay sticking Upon examination of the removed starter relay I see that it is a continuous duty relay. It has now been replaced with an intermittent duty relay of appropriate capacity. Thank you for the help everyone but looks like this one was obvious. On Thu, Dec 27, 2018 at 9:18 AM Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 07:14 PM 12/24/2018, you wrote: > > We had a strange event last week with our O-200 powered CH750. After > running the battery down during a fuel gauge calibration that lasted over > an hour, one of our pilots tried to start the engine to taxi back but with > the already depleted battery and a less than perfect start procedure they > gave up after a couple weak start attempts. I walked over to the aircraft > to brief them on a prop start and when I asked for the master on the > starter ran. > > > The vast majority of starter contactor > sticking events occur during an attempt > to crank the engine with a weak battery. > The fact that you got immediate starter > action on closure of the master switch > says your starter contactor was 'stuck' > shut. > > Shut the master off, cycled the start button rapidly a dozen times, > master on again and the starter ran again. I could hear the starter relay > clicking loudly each time power was applied so it does not seem like there > was a physical failure of the relay but more some electrical short > activating the relay each time power was applied. > > > Contacts are welded . . . > > > The build team inspected the relay and found a loose connection. > Tightening it took the problem from continuous to intermittent; in their > words "it's fixed but it did it again once". > > We have removed the relay for replacement, I still think the switch is > suspect but they've decided the problem is the relay. Does the aeroelectric > list think there would be value in cutting open the relay and examining it? > Any suggestions on how best to do so? > > > Go to a car parts store and pick > up a starter contactor that looks > like the one in the aircraft spruce > catalog . . . it will work just fine. > See if the contactor is marked "diode > suppressed" or has the word diode on it > anywhere or on the packaging. > > [image: Emacs!] > > > Bob . . . > ________________________________ Message 14 ____________________________________ Time: 03:35:04 PM PST US Subject: AeroElectric-List: Re: Alternator/shunt question From: "supik" nuckolls.bob(at)aeroelect wrote: > At 01:32 PM 1/4/2019, you wrote: > > > > > Art, that's my concern.. I think that's not enough Volts to charge the battery.. > > > > > > One does not CHARGE a battery with the standby > alternator . . . you only support the bus > at some level that prevents DISCHARGING > the battery. > > The idea is to minimize loads to some > level at or below what the standby > alternator will deliver thus holding > the battery in reserve for approach > to landing > > > > Bob . . . Bob, I don't get it. B&C says the standby alt can be configured with both the normal or the standby regulator. Therefore I assume that this 30A alt is able to charge a battery. Flipping 1 switch I am able to shed loads immediately to 19amps (that's what the e-bus typically consumes). Now I have approx. 11amps left depending on RPM -why not use that power to charge the battery? thanks, -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486716#486716 ________________________________ Message 15 ____________________________________ Time: 04:13:45 PM PST US From: Subject: RE: AeroElectric-List: Re: Alternator/shunt question OK - this may be my first "contribution" to the discussion, based on what I've learned here. Here goes: Igor, If I understand correctly, other than briefly after starting (when the 60-amp alternator would be handling the duties), the battery should already be fully charged, and operating strictly as a "backup" to the dual-alternator system. Thus, if the primary (60Amp) alternator were to fail, the backup (30Amp) alternator would take over powering the aircraft's electrical system. It is only if BOTH the primary (60Amp) and backup (30Amp) alternators were to fail that the battery would begin to be discharged. If both alternators were to fail while the battery was still being recharged, you'd likely still be on the ground taxiing, and I would think that would constitute enough of an 'emergency' to scrub the flight... Bob, et al, how'd I do? Jim Parker (Complete rookie at all things electrical, but hopefully beginning to have a clue...) -------- Original Message -------- Subject: AeroElectric-List: Re: Alternator/shunt question From: "supik" nuckolls.bob(at)aeroelect wrote: > At 01:32 PM 1/4/2019, you wrote: > > > > > Art, that's my concern.. I think that's not enough Volts to charge the battery.. > > > > > > One does not CHARGE a battery with the standby > alternator . . . you only support the bus > at some level that prevents DISCHARGING > the battery. > > The idea is to minimize loads to some > level at or below what the standby > alternator will deliver thus holding > the battery in reserve for approach > to landing > > > > Bob . . . Bob, I don't get it. B&C says the standby alt can be configured with both the normal or the standby regulator. Therefore I assume that this 30A alt is able to charge a battery. Flipping 1 switch I am able to shed loads immediately to 19amps (that's what the e-bus typically consumes). Now I have approx. 11amps left depending on RPM -why not use that power to charge the battery? thanks, -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486716#486716 ________________________________ Message 16 ____________________________________ Time: 04:18:59 PM PST US From: don van santen Subject: Re: AeroElectric-List: Re: Alternator/shunt question If your primary alt failed in the first ten minutes of flight your battery may not be fully charged. If this is true just return to the departure airport. If the battery was fully charged before take off and the alt failure was more than 10 to 15 minutes later your battery is fully recharged anyway. Either way you do not need to charge the battery with the secondary alt. On Fri, Jan 4, 2019, 15:39 supik > > nuckolls.bob(at)aeroelect wrote: > > At 01:32 PM 1/4/2019, you wrote: > > > > > > > > Art, that's my concern.. I think that's not enough Volts to charge > the battery.. > > > > > > > > > > One does not CHARGE a battery with the standby > > alternator . . . you only support the bus > > at some level that prevents DISCHARGING > > the battery. > > > > The idea is to minimize loads to some > > level at or below what the standby > > alternator will deliver thus holding > > the battery in reserve for approach > > to landing > > > > > > > > Bob . . . > > > Bob, > > I don't get it. B&C says the standby alt can be configured with both the > normal or the standby regulator. Therefore I assume that this 30A alt is > able to charge a battery. > > Flipping 1 switch I am able to shed loads immediately to 19amps (that's > what the e-bus typically consumes). Now I have approx. 11amps left > depending on RPM -why not use that power to charge the battery? > > thanks, > > -------- > Igor > > RV10 in progress > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=486716#486716 > > ________________________________ Message 17 ____________________________________ Time: 04:40:20 PM PST US Subject: AeroElectric-List: Re: Alternator/shunt question From: "supik" jim(at)PoogieBearRanch.co wrote: > OK - this may be my first "contribution" to the discussion, based on > what I've learned here. Here goes: > > Igor, > > If I understand correctly, other than briefly after starting (when the > 60-amp alternator would be handling the duties), the battery should > already be fully charged, and operating strictly as a "backup" to the > dual-alternator system. Thus, if the primary (60Amp) alternator were to > fail, the backup (30Amp) alternator would take over powering the > aircraft's electrical system. It is only if BOTH the primary (60Amp) > and backup (30Amp) alternators were to fail that the battery would begin > to be discharged. > > If both alternators were to fail while the battery was still being > recharged, you'd likely still be on the ground taxiing, and I would > think that would constitute enough of an 'emergency' to scrub the > flight... > > Bob, et al, how'd I do? > > Jim Parker (Complete rookie at all things electrical, but hopefully > beginning to have a clue...) > > > ------ Jim, That's exactly my idea. thanks! Normal flight starts with a healthy battery and 2 alternators. Main alternator fails: load shedding follows, Stby alternator takes over the reduced load & keeps the battery charged. I land, refuel and continue home in Day VFR with load shedded and battery maintained charged. I am not forced to replace or repair the Main alt after my first landing. In case the Stby alternator fails too (dual alt failure) -land ASAP (emergency) -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486719#486719 ________________________________ Message 18 ____________________________________ Time: 05:08:14 PM PST US Subject: Re: AeroElectric-List: Re: Alternator/shunt question From: Charlie England On 1/4/2019 6:39 PM, supik wrote: > > > jim(at)PoogieBearRanch.co wrote: >> OK - this may be my first "contribution" to the discussion, based on >> what I've learned here. Here goes: >> >> Igor, >> >> If I understand correctly, other than briefly after starting (when the >> 60-amp alternator would be handling the duties), the battery should >> already be fully charged, and operating strictly as a "backup" to the >> dual-alternator system. Thus, if the primary (60Amp) alternator were to >> fail, the backup (30Amp) alternator would take over powering the >> aircraft's electrical system. It is only if BOTH the primary (60Amp) >> and backup (30Amp) alternators were to fail that the battery would begin >> to be discharged. >> >> If both alternators were to fail while the battery was still being >> recharged, you'd likely still be on the ground taxiing, and I would >> think that would constitute enough of an 'emergency' to scrub the >> flight... >> >> Bob, et al, how'd I do? >> >> Jim Parker (Complete rookie at all things electrical, but hopefully >> beginning to have a clue...) >> >> >> ------ > > Jim, > > That's exactly my idea. thanks! > > Normal flight starts with a healthy battery and 2 alternators. > > Main alternator fails: load shedding follows, Stby alternator takes over the reduced load & keeps the battery charged. I land, refuel and continue home in Day VFR with load shedded and battery maintained charged. I am not forced to replace or repair the Main alt after my first landing. > > In case the Stby alternator fails too (dual alt failure) -land ASAP (emergency) > > -------- > Igor > > I think one tripping point for some, is that the lower setpoint for the standby alt is so that it will automatically come on line if the primary fails. (The lower setpoint means that the standby regulator sees no need to supply field current, since the system is already above its setpoint. A byproduct is that when the system voltage drops to the standby setpoint, the low voltage monitor will notify the pilot that he's now running on 'backup' alternator power. If the standby had the same setpoint, you'd never get a notification of the primary's failure. So, you get multiple uses from one adjustment, instead of extra hardware. Another tripping point is 'keeping the battery charged'. That's not what's happening on a typical flight. We crank up (slight discharge), then the alternator picks up all the a/c loads plus recharges the battery. Once the battery is fully charged (fairly quickly for a healthy battery and an uneventful start), the alternator isn't 'keeping the battery charged'; it's just supplying the electrical loads of the a/c. (Over the course of a typical flight, and for quite a while afterward, the battery doesn't need to be kept charged. I've had normal starts from a no-name generic SLA battery after it's been sitting in the plane for a month or more.) So.... once you've been flying for 10-15 minutes, in all probability your battery is fully charged. At any point in the flight after that, you have a fully charged battery on board if the primary alt fails. The standby then takes over at 13+ volts, running the a/c appliances, which will operate just fine on 12V. Since you're operating above the fully charged voltage level of the battery, it will not discharge during the flight. You always have the option to use the same regulator setpoints for both alternators, and set up some other monitoring system to notify you and/or switch to the backup. I'm running two identical alternators on my alternative engine and will be doing just that. Charlie --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 19 ____________________________________ Time: 06:01:45 PM PST US Subject: AeroElectric-List: Re: Alternator/shunt question From: "supik" [quote="ceengland7(at)gmail.com"]On 1/4/2019 6:39 PM, supik wrote: > > If the standby had the same > setpoint, you'd never get a notification of the primary's failure. > The Stby setpoint would be 14.1V (good enough for bat recharge and monitoring funciton of the Stby alt comming online) and the Main alt's setpoint 14.7V. Does that make sense? [quote="ceengland7(at)gmail.com"]On 1/4/2019 6:39 PM, supik wrote: > > Another tripping point is 'keeping the battery charged'. That's not > what's happening on a typical flight. We crank up (slight discharge), > then the alternator picks up all the a/c loads plus recharges the > battery. Once the battery is fully charged (fairly quickly for a healthy > battery and an uneventful start), the alternator isn't 'keeping the > battery charged'; it's just supplying the electrical loads of the a/c. > (Over the course of a typical flight, and for quite a while afterward, > the battery doesn't need to be kept charged. > That's correct, we are not talking about a typical flight. It's a 'get aircraft home mode' in good weather and day conditions (sorry for repeating myself again). The calculated typical e-bus draw is supposed to be at 19Amps. With intermittent loads (engine start, flaps extension/retraction etc) the loads will get above 30Amps for a short period of time where the battery's capacity will take over. After the peak draw is over, the Stby alternator would be able to recharge the battery again. This assures that I land with a fully charged battery -good for another engine start. Shall the Stby alt fail in flight (dual alt failure), this would leave me with a fully charged battery for 'emergency land ASAP mode' anytime except shortly after the battery took over to supply some peak draw, where I expect the peak draws to happen during take off and landing, not so much during cruise.. Am I missing something? Thanks, -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486721#486721 ________________________________ Message 20 ____________________________________ Time: 06:28:39 PM PST US From: don van santen Subject: Re: AeroElectric-List: Re: Alternator/shunt question It seems that you want to do something that a standby system was never meant to do. If you insist on being able to make multiple departures after the primary alt quits, maybe you should use 2 60 amp alternators with independant controls. a better plan would be to use tje secondary system as dezigned and continue your flight as far as the fuel on board allows, land and make repairs and then continue on. Irf your car breaks down do stop for repairs or try to drive it home? On Fri, Jan 4, 2019, 18:06 supik > [quote="ceengland7(at)gmail.com"]On 1/4/2019 6:39 PM, supik wrote: > > > > > If the standby had the same > > setpoint, you'd never get a notification of the primary's failure. > > > > > The Stby setpoint would be 14.1V (good enough for bat recharge and > monitoring funciton of the Stby alt comming online) and the Main alt's > setpoint 14.7V. Does that make sense? > > > [quote="ceengland7(at)gmail.com"]On 1/4/2019 6:39 PM, supik wrote: > > > > > Another tripping point is 'keeping the battery charged'. That's not > > what's happening on a typical flight. We crank up (slight discharge), > > then the alternator picks up all the a/c loads plus recharges the > > battery. Once the battery is fully charged (fairly quickly for a healthy > > battery and an uneventful start), the alternator isn't 'keeping the > > battery charged'; it's just supplying the electrical loads of the a/c. > > (Over the course of a typical flight, and for quite a while afterward, > > the battery doesn't need to be kept charged. > > > > > That's correct, we are not talking about a typical flight. It's a 'get > aircraft home mode' in good weather and day conditions (sorry for repeating > myself again). The calculated typical e-bus draw is supposed to be at > 19Amps. > > With intermittent loads (engine start, flaps extension/retraction etc) the > loads will get above 30Amps for a short period of time where the battery's > capacity will take over. After the peak draw is over, the Stby alternator > would be able to recharge the battery again. This assures that I land with > a fully charged battery -good for another engine start. > > Shall the Stby alt fail in flight (dual alt failure), this would leave me > with a fully charged battery for 'emergency land ASAP mode' anytime except > shortly after the battery took over to supply some peak draw, where I > expect the peak draws to happen during take off and landing, not so much > during cruise.. > > Am I missing something? > > Thanks, > > -------- > Igor > > RV10 in progress > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=486721#486721 > > ________________________________ Message 21 ____________________________________ Time: 06:52:35 PM PST US Subject: Re: AeroElectric-List: Re: Alternator/shunt question From: Charlie England On 1/4/2019 8:00 PM, supik wrote: > > [quote="ceengland7(at)gmail.com"]On 1/4/2019 6:39 PM, supik wrote: > >> >> If the standby had the same >> setpoint, you'd never get a notification of the primary's failure. >> > > > The Stby setpoint would be 14.1V (good enough for bat recharge and monitoring funciton of the Stby alt comming online) and the Main alt's setpoint 14.7V. Does that make sense? > > > [quote="ceengland7(at)gmail.com"]On 1/4/2019 6:39 PM, supik wrote: > >> >> Another tripping point is 'keeping the battery charged'. That's not >> what's happening on a typical flight. We crank up (slight discharge), >> then the alternator picks up all the a/c loads plus recharges the >> battery. Once the battery is fully charged (fairly quickly for a healthy >> battery and an uneventful start), the alternator isn't 'keeping the >> battery charged'; it's just supplying the electrical loads of the a/c. >> (Over the course of a typical flight, and for quite a while afterward, >> the battery doesn't need to be kept charged. >> > > That's correct, we are not talking about a typical flight. It's a 'get aircraft home mode' in good weather and day conditions (sorry for repeating myself again). The calculated typical e-bus draw is supposed to be at 19Amps. > > With intermittent loads (engine start, flaps extension/retraction etc) the loads will get above 30Amps for a short period of time where the battery's capacity will take over. After the peak draw is over, the Stby alternator would be able to recharge the battery again. This assures that I land with a fully charged battery -good for another engine start. > > Shall the Stby alt fail in flight (dual alt failure), this would leave me with a fully charged battery for 'emergency land ASAP mode' anytime except shortly after the battery took over to supply some peak draw, where I expect the peak draws to happen during take off and landing, not so much during cruise.. > > Am I missing something? > > Thanks, > > -------- > Igor > > Well, the designer is a pretty sharp dude. I suspect that if the system operation would be stable at those settings, he'd have used them. I suspect that you'll find that system voltage in an a/c isn't particularly stable, and setting the margin that close will give lots of 'nuisance trips'. But this is experimental aviation; give it a shot & let us know how it goes. Charlie --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 22 ____________________________________ Time: 07:03:19 PM PST US Subject: AeroElectric-List: Re: Alternator/shunt question From: "supik" donvansanten(at)gmail.com wrote: > It seems that you want to do something that a standby system was never meant to do. If you insist on being able to make multiple departures after the primary alt quits, maybe you should use 2 60 amp alternators with independant controls. a better plan would be to use tje secondary system as dezigned and continue your flight as far as the fuel on board allows, land and make repairs and then continue on. Irf your car breaks down do stop for repairs or try to drive it home? > I understand, the system wasn't designed with my plan in mind. The question is: Is it possible to apply my idea as requested or won't physics allow it? When I look at the gear driven main B&C 462H (60amp) alternator -it is supposed to deliver 41.3Amps at cruise RPM 2450. This is 11.3 Amps more than the 30Amps Stby Alt. This would not leave me with 2 identical alternators either. One can wait for a week or more before the replacement unit arrives in Europe. We have a completely different network here. Further, you will hardly find a service center willing to touch an experimental. It is quite common in airlines that items get on MEL (minimum equipment list) if they fail and the airplane can depart for another flight although limited by weather or any other restriction. It doesn't mean that you are grounded as soon as something fails, provided there is a backup system available and functional. Not to compare to cars.. -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486724#486724 ________________________________ Message 23 ____________________________________ Time: 07:19:27 PM PST US Subject: AeroElectric-List: Re: Alternator/shunt question From: "supik" ceengland7(at)gmail.com wrote: > : > > operation would be stable at those settings, he'd have used them. I > suspect that you'll find that system voltage in an a/c isn't > particularly stable, and setting the margin that close will give lots of > 'nuisance trips'. But this is experimental aviation; give it a shot & > let us know how it goes. > > Charlie > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus That's a good point Charlie, it might trigger the Stby Alt (online) warning light for example right after engine start, taxiing with all el. equipment on. The same might happen in an aircraft with single battery and single alternator setup when after engine start and on idle rpm a lot of el. equipment is turned on. Anything else to consider? -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486725#486725 ________________________________ Message 24 ____________________________________ Time: 07:47:25 PM PST US Subject: Re: AeroElectric-List: Re: Alternator/shunt question From: Charlie England On 1/4/2019 9:18 PM, supik wrote: > > > ceengland7(at)gmail.com wrote: >> : >> >> operation would be stable at those settings, he'd have used them. I >> suspect that you'll find that system voltage in an a/c isn't >> particularly stable, and setting the margin that close will give lots of >> 'nuisance trips'. But this is experimental aviation; give it a shot & >> let us know how it goes. >> >> Charlie >> >> --- >> This email has been checked for viruses by Avast antivirus software. >> https://www.avast.com/antivirus > > That's a good point Charlie, it might trigger the Stby Alt (online) warning light for example right after engine start, taxiing with all el. equipment on. The same might happen in an aircraft with single battery and single alternator setup when after engine start and on idle rpm a lot of el. equipment is turned on. > > Anything else to consider? > > -------- > Igor > With the exception of some of the really small alternators, like the small Permanent Magnet 'dynamos', That doesn't happen. (Empirical evidence, looking at virtually all planes flying (and cars driving) with modern alternators.) What I'm talking about is normal operation, as larger loads come & go in the system, if the two setpoints are only .5V apart. ________________________________ Message 25 ____________________________________ Time: 08:10:53 PM PST US Subject: Re: AeroElectric-List: Re: Alternator/shunt question From: Charlie England On 1/4/2019 9:02 PM, supik wrote: > > > donvansanten(at)gmail.com wrote: >> It seems that you want to do something that a standby system was never meant to do. If you insist on being able to make multiple departures after the primary alt quits, maybe you should use 2 60 amp alternators with independant controls. a better plan would be to use tje secondary system as dezigned and continue your flight as far as the fuel on board allows, land and make repairs and then continue on. Irf your car breaks down do stop for repairs or try to drive it home? >> > > I understand, the system wasn't designed with my plan in mind. The question is: Is it possible to apply my idea as requested or won't physics allow it? > > When I look at the gear driven main B&C 462H (60amp) alternator -it is supposed to deliver 41.3Amps at cruise RPM 2450. This is 11.3 Amps more than the 30Amps Stby Alt. This would not leave me with 2 identical alternators either. > > One can wait for a week or more before the replacement unit arrives in Europe. We have a completely different network here. Further, you will hardly find a service center willing to touch an experimental. > > It is quite common in airlines that items get on MEL (minimum equipment list) if they fail and the airplane can depart for another flight although limited by weather or any other restriction. It doesn't mean that you are grounded as soon as something fails, provided there is a backup system available and functional. Not to compare to cars.. > > -------- > Igor > To address the supply chain delay issue, I'd suggest a consult with B&C about whether their regulators are 'married' to their alternators. There are *many* off-the-shelf automotive alternators that will fit on the forward mount of a Lyc. And with proper hookup to an alternator made for external regulation a regulator is just a regulator. So with the right automotive part # in hand, you should be able to local source a temporary replacement for the belt driven model. To address the short term 'continue the mission' issue, I note that the 462H data sheet says that "may be used as either a Primary or a Standby Alternator, depending on your electrical system configuration." With that knowledge in hand, and care in the regulator mounting locations and harness design, if you have a primary *alternator* failure you'd have the option upon next landing to move the standby alternator control to the primary regulator. Now the only failure that keeps you at 13.5V would be failure of the primary *regulator*. If it's that important to have 100% dispatch, carry a spare regulator. Charlie --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 26 ____________________________________ Time: 08:21:23 PM PST US Subject: AeroElectric-List: Re: Alternator/shunt question From: "supik" ceengland7(at)gmail.com wrote: > On 1/4/2019 9:18 PM, supik wrote: > > > > > > > > > ceengland7(at)gmail.com wrote: > > > : > > > > > > operation would be stable at those settings, he'd have used them. I > > > suspect that you'll find that system voltage in an a/c isn't > > > particularly stable, and setting the margin that close will give lots of > > > 'nuisance trips'. But this is experimental aviation; give it a shot & > > > let us know how it goes. > > > > > > Charlie > > > > > > --- > > > This email has been checked for viruses by Avast antivirus software. > > > https://www.avast.com/antivirus > > > > That's a good point Charlie, it might trigger the Stby Alt (online) warning light for example right after engine start, taxiing with all el. equipment on. The same might happen in an aircraft with single battery and single alternator setup when after engine start and on idle rpm a lot of el. equipment is turned on. > > > > Anything else to consider? > > > > -------- > > Igor > > > > With the exception of some of the really small alternators, like the > > > > small Permanent Magnet 'dynamos', That doesn't happen. (Empirical > evidence, looking at virtually all planes flying (and cars driving) with > modern alternators.) > > What I'm talking about is normal operation, as larger loads come & go in > the system, if the two setpoints are only .5V apart. This might be indeed the limiting factor.. I'll check the battery's minimum charging voltage with the manufacturer. Thanks, -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486728#486728 ________________________________ Message 27 ____________________________________ Time: 08:32:42 PM PST US Subject: AeroElectric-List: Re: Alternator/shunt question From: "user9253" 14.7 volts is a little too much for continuous charging. You do not want to damage the battery. Odyssey recommends 13.6 for continuous float charge. There are hundreds of RV-12s flying whose Ducati regulators are set at 13.8 volts, enough to keep the battery charged. How about setting the main regulator at 14.3 or 14.4 and set the standby regulator at 13.7 or 13.8 which will keep the battery charged. And there will be enough voltage differential spread to warn of low voltage if the main alternator fails. > For this setup I need the Aux Alternator to be able to charge at min > 14.1V to recharge the battery -correct? No, 13.8 is enough. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486729#486729 ________________________________ Message 28 ____________________________________ Time: 08:49:29 PM PST US Subject: AeroElectric-List: Re: Alternator/shunt question From: "supik" user9253 wrote: > 14.7 volts is a little too much for continuous charging. You do not want to > damage the battery. Odyssey recommends 13.6 for continuous float charge. > There are hundreds of RV-12s flying whose Ducati regulators are set at 13.8 > volts, enough to keep the battery charged. How about setting the main > regulator at 14.3 or 14.4 and set the standby regulator at 13.7 or 13.8 which > will keep the battery charged. And there will be enough voltage differential > spread to warn of low voltage if the main alternator fails. > > > For this setup I need the Aux Alternator to be able to charge at min > > 14.1V to recharge the battery -correct? > No, 13.8 is enough. I am planing to go with the Concorde RG-25XC (12V, 24Ah) Thanks for mentioning this, but still, 14.4 - 13.8 gives a 0.6V difference. -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486730#486730 ________________________________ Message 29 ____________________________________ Time: 09:10:53 PM PST US Subject: AeroElectric-List: Re: Alternator/shunt question From: "supik" In one of the previous posts, Bob replies to OP: 'SB-1 is set too low. It only needs to be 0.7v or so below your main alternator set point. Bob . . .' So 0.6V difference might actually work.. ?? -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486731#486731 ________________________________ Message 30 ____________________________________ Time: 09:34:43 PM PST US Subject: Re: AeroElectric-List: Re: Alternator/shunt question From: Kelly McMullen No alternator should be run at greater than 80% of its rating for any length of time. So don't figure the backup at more than 24 amps. Even an AGM battery will charge (perhaps slowly) at any voltage over 13 volts. Almost all 14 V aircraft electrowhizzies will operate fine on 13V. If you intend to limp home on the back up alternator, know what you need electrically and assume you get only partial recharge of battery after starter draw. I don't know how high adjustable regulators will let you go, but there really isn't much reason to have the primary operate above 14.5, and you probably want the standby to be at something more like 13.5-13.8. Not sure what the mission is calling for two alternators with one battery. I've been flying 2.5 years in my RV-10 with one alternator, one Odyssey 925L battery, and a backup battery on each of two EFIS. The Odyssey is considerably cheaper than a Concorde or Gill, has very comparable capacity and better cranking. Also fits in the battery tray with room to spare. Of course if battery fails where only certified aircraft batteries are available, the Concorde will bolt right in. If you are trying to power two electronic ignitions, you may want to think about 2 batteries. Kelly On 1/4/2019 8:02 PM, supik wrote: > > > donvansanten(at)gmail.com wrote: >> It seems that you want to do something that a standby system was never meant to do. If you insist on being able to make multiple departures after the primary alt quits, maybe you should use 2 60 amp alternators with independant controls. a better plan would be to use tje secondary system as dezigned and continue your flight as far as the fuel on board allows, land and make repairs and then continue on. Irf your car breaks down do stop for repairs or try to drive it home? >> > > > I understand, the system wasn't designed with my plan in mind. The question is: Is it possible to apply my idea as requested or won't physics allow it? > > When I look at the gear driven main B&C 462H (60amp) alternator -it is supposed to deliver 41.3Amps at cruise RPM 2450. This is 11.3 Amps more than the 30Amps Stby Alt. This would not leave me with 2 identical alternators either. > > One can wait for a week or more before the replacement unit arrives in Europe. We have a completely different network here. Further, you will hardly find a service center willing to touch an experimental. > > It is quite common in airlines that items get on MEL (minimum equipment list) if they fail and the airplane can depart for another flight although limited by weather or any other restriction. It doesn't mean that you are grounded as soon as something fails, provided there is a backup system available and functional. Not to compare to cars.. > > -------- > Igor > > RV10 in progress > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=486724#486724 > > > > > > > > > ------------------------------------------------------------------------------------- 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.