---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 06/12/18: 19 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:04 AM - Question on Z-14 System (Rocketman1988) 2. 09:28 AM - Re: Alternator Noise When Touching Metal Airframe Grounds (Eric M. Jones) 3. 11:19 AM - Re: Question on Z-14 System (Robert Reed) 4. 11:36 AM - Re: Question on Z-14 System (Robert L. Nuckolls, III) 5. 12:27 PM - Re: Alternator Noise When Touching Metal Airframe Grounds (Robert L. Nuckolls, III) 6. 01:02 PM - Re: Alternator Noise When Touching Metal Airframe Grounds (Jared Yates) 7. 01:57 PM - Ducati Regulator (too little load) (Ken Ryan) 8. 03:12 PM - Re: Alternator Noise When Touching Metal Airframe Grounds (Robert L. Nuckolls, III) 9. 03:13 PM - Re: Alternator Noise When Touching Metal Airframe Grounds (Robert L. Nuckolls, III) 10. 03:46 PM - Sequence for bringing alternators on line. (Sebastien) 11. 04:26 PM - Re: Ducati Regulator (too little load) (user9253) 12. 04:39 PM - Re: Re: Ducati Regulator (too little load) (Ernest Christley) 13. 05:18 PM - Re: Ducati Regulator (too little load) (user9253) 14. 05:34 PM - Re: Re: Ducati Regulator (too little load) (GTH) 15. 06:13 PM - Re: Re: Ducati Regulator (too little load) (Ken Ryan) 16. 06:28 PM - Re: Re: Ducati Regulator (too little load) (Lyle Peterson) 17. 07:08 PM - Re: Sequence for bringing alternators on line. (user9253) 18. 09:56 PM - Re: Re: Ducati Regulator (too little load) (Robert L. Nuckolls, III) 19. 09:59 PM - Re: Re: Ducati Regulator (too little load) (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 09:04:45 AM PST US Subject: AeroElectric-List: Question on Z-14 System From: "Rocketman1988" I am planning on the Z-14 system in my RV-10. I have dual alternators, dual batteries, electronic ignition, and electronic fuel injection (Dual EFII System). Looking at the schematic, it appears that ECU 1 / Fuel Pump 1 would be on the main battery bus and ECU 2 / Fuel Pump 2 would be on the aux battery bus. This arrangement means power is always available to those items, even when the battery masters are OFF. I am planning on fuel pump ON/OFF switches and could also switch the individual ECU power lines. Anyone (maybe Bob?) care to weigh in on this arrangement? Thanks! Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480820#480820 ________________________________ Message 2 _____________________________________ Time: 09:28:36 AM PST US Subject: AeroElectric-List: Re: Alternator Noise When Touching Metal Airframe Grounds From: "Eric M. Jones" Reposted from a few years ago, but this might help. EDN of 23NOV1995 had an article entitled: "Assume nothing. Test everything." which was a small guide to troubleshooting philosophy (although aimed more at computers and high falutin designs but applicable to life in general). He (Jack Ganssle) taught some critical elements of troubleshooting that have helped me over the years. Allow me to share some of them them with you: 1) EVERYTHING YOU KNOW IS WRONG. I.e. Assume nothing. Is it really connected like you think? Are your measuring instrument working? Etc. To facilitate this process--> 2) Keep a notebook of what you are doing, what you suspect, random suspicions, sketches, details, notes for later improvements, hard-to-read numbers, EVERYTHING. When you review your notebook the next day, important clues will often jump out. 3) Start with an organized workbench with all tools at the ready. What are you going to need to test assumptions? 4) Ask for help. Don't be shy! Anybody can help by listening to your explanation...where the obvious might jump out.... Asking experts is how you'll learn, even if they don't have the answer. 5) Use the Internet. Hardly a day goes by without someone asking me a question and I reply (or would like to reply) "Let me Google that for you". Google has developed the ability to understand plain language questions. The value of searching the 'net cannot be overstated. And it will only get better. 6) Remember, most problems have simple answers. Think "Connectors" not Integrated Circuits. Think "Horses" not Zebras. We can all add tips to this list. I ould also add my paper on Dabbling with Electricity. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480821#480821 Attachments: http://forums.matronics.com//files/dabbling_with_electricity_a_135.pdf ________________________________ Message 3 _____________________________________ Time: 11:19:46 AM PST US From: Robert Reed Subject: Re: AeroElectric-List: Question on Z-14 System I am using the same configuration with each of the two power buses on guard ed switches and powering only the ECI and Fuel Pumps.=C2- My original con figuration was using the FADEC system but have replaced with the Dual FlyEf ii system. Bob Reed From: Rocketman1988 To: aeroelectric-list@matronics.com Sent: Tuesday, June 12, 2018 11:05 AM Subject: AeroElectric-List: Question on Z-14 System .com> I am planning on the Z-14 system in my RV-10.=C2- I have dual alternators , dual batteries, electronic ignition, and electronic fuel injection (Dual EFII System). Looking at the schematic, it appears that ECU 1 / Fuel Pump 1 would be on t he main battery bus and ECU 2 / Fuel Pump 2 would be on the aux battery bus .. This arrangement means power is always available to those items, even when the battery masters are OFF. I am planning on fuel pump ON/OFF switches and could also switch the indivi dual ECU power lines.=C2- Anyone (maybe Bob?) care to weigh in on this arrangement? Thanks! Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480820#480820 - S - WIKI - - =C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin. ________________________________ Message 4 _____________________________________ Time: 11:36:31 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Question on Z-14 System At 11:04 AM 6/12/2018, you wrote: > > >I am planning on the Z-14 system in my RV-10. I have dual >alternators, dual batteries, electronic ignition, and electronic >fuel injection (Dual EFII System). > >Looking at the schematic, it appears that ECU 1 / Fuel Pump 1 would >be on the main battery bus and ECU 2 / Fuel Pump 2 would be on the >aux battery bus. > >This arrangement means power is always available to those items, >even when the battery masters are OFF. > >I am planning on fuel pump ON/OFF switches and could also switch the >individual ECU power lines. > >Anyone (maybe Bob?) care to weigh in on this arrangement? That's the idea. Electrically dependent engine accessories driven from battery busses are avaiable even when the electrical system(s) are shut down . . . as in case of smoke in the cockpit. The only operational concerns to explore are potential difficulties if BOTH primary and secondary accessories are energized at the same time. Had a Z-14 builder some years back with dual ECU's sthat would argue with each other if energized at the same time. We arranged for a little lockout mechanism that prevented a BOTH on at the same time. There was no hazard for having other dual accessories energized at the same time. We machined the lock out of a piece of 1/2" aluminum. It mounted between the two ECU switches on a single screw. Bob . . . ________________________________ Message 5 _____________________________________ Time: 12:27:46 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Alternator Noise When Touching Metal Airframe Grounds At 08:44 PM 6/11/2018, you wrote: >Thanks for your help Bob. It's a 4-place airplane with stereo >panel-powered Lemo jacks, parallel two-plug jacks (all isolated from >the airframe) and a PS Engineering PAR100EX audio panel/intercom. In >the past I've played with the volume controls but didn't think to >try it out on this most recent flight. In the past, the noise was >reduced when I turned down the intercom volume level, or the local >headset level on the Bose X. Okay, the fact that intercom volume has an effect suggests that the noise is getting in upstream of the intercom. The "touch sensitivity" is suggestive of a possible poor or even floating ground in the upstream wiring. Downloaded the manual . . . do you have the remotely controlled comm transceiver? Bob . . . ________________________________ Message 6 _____________________________________ Time: 01:02:20 PM PST US From: Jared Yates Subject: Re: AeroElectric-List: Alternator Noise When Touching Metal Airframe Grounds Yes, and also a gns430w and skyview system. On June 12, 2018 15:39:16 "Robert L. Nuckolls, III" wrote: > At 08:44 PM 6/11/2018, you wrote: > >> Thanks for your help Bob. It's a >> 4-place airplane with stereo panel-powered Lemo jacks, parallel two-plug >> jacks (all isolated from the airframe) and a PS Engineering PAR100EX >> audio panel/intercom. In the past I've played with the volume controls >> but didn't think to try it out on this most recent flight. In the past, >> the noise was reduced when I turned down the intercom volume level, or >> the local headset level on the Bose X. > > > Okay, the fact that intercom volume has > an effect suggests that the noise is getting > in upstream of the intercom. The "touch > sensitivity" is suggestive of a possible > poor or even floating ground in the > upstream wiring. > > Downloaded the manual . . . do you have > the remotely controlled comm transceiver? > > > Bob . . . ________________________________ Message 7 _____________________________________ Time: 01:57:20 PM PST US From: Ken Ryan Subject: AeroElectric-List: Ducati Regulator (too little load) There is a respected member of a popular Rotax list asserting that the Ducati regulator can be harmed by too little load. I don't believe this to be true, and it interests me directly because my wiring architecture has the regulator, under normal conditions, supplying only my primary fuel pump (it can be tied to the main bus if necessary). To those of you familiar with the Ducati regulator, is there any truth in the assertion that a light load is bad for it? Ken Ryan ________________________________ Message 8 _____________________________________ Time: 03:12:33 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Alternator Noise When Touching Metal Airframe Grounds At 03:01 PM 6/12/2018, you wrote: >Yes, and also a gns430w and skyview system. Just for grins . . . try unplugging the data cable between the intercom/controll panel and the remote transceiver . . . and see if the noise is affected. Bob . . . ________________________________ Message 9 _____________________________________ Time: 03:13:41 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Alternator Noise When Touching Metal Airframe Grounds At 03:01 PM 6/12/2018, you wrote: >Yes, and also a gns430w and skyview system. Just for grins . . . try unplugging the data cable between the intercom/controll panel and the remote transceiver . . . and see if the noise is affected. Oh yeah, are you sure it's alternator whine . . . pitch rises and falls with engine rpm? Bob . . . ________________________________ Message 10 ____________________________________ Time: 03:46:59 PM PST US From: Sebastien Subject: AeroElectric-List: Sequence for bringing alternators on line. I am writing checklists for a new homebuilt I will be doing the flight testing on. Aircraft has a 40A main alternator and an SD-8 backup alternator. The alternator switch allows either the main or backup alternator to be on and also has an off position. I'm thinking of leaving the switch on the main alternator all the time, except for a test of the SD-8 during the runup. Does anyone see a problem with this plan or should I wait until the load on the electrical system has come down to a certain point before switching to the SD-8? As far as I know the SD-8 will put out whatever it can and any load in excess will simply come from the battery. Is it reasonable to test the SD-8 every flight or is this something that can be done on a monthly or quarterly basis? Also I have run into a couple pilots recently who start their engines with the alternator off in order to "prevent damage to the alternator during start". I can't remember any mention of this in the AEC. Is there any basis for this? Should I turn the alternator off before shutdown and then on after startup? I have attached the main electrical system diagram for the aircraft in question. Thank you, Sebastien ________________________________ Message 11 ____________________________________ Time: 04:26:29 PM PST US Subject: AeroElectric-List: Re: Ducati Regulator (too little load) From: "user9253" I am on your side Ken. Roger should should reference the schematic and the laws of physics to explain why too little of a load can damage the rectifier/regulator. The greater the current, the greater the heat. A small load will result in less heat. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480834#480834 ________________________________ Message 12 ____________________________________ Time: 04:39:58 PM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Re: Ducati Regulator (too little load) Some regulators "regulate" by dumping the excess power generated by the gen erator.=C2- They dump the power by shorting it to ground.=C2- A direct short would be a weld, so the regulator stands in the middle and acts as a heater.=C2- If there is no load on the electrical system, the regulator i s being heated by everything the generator can put out. But, really, it is a poor engineer that could not have anticipated and and properly designed for that eventuality.=C2- Of course, the proper design may have been to install it in the exact position on the motorcycle that th ey designed it to be install in (with its accompanying blast air). On Tuesday, June 12, 2018 7:27 PM, user9253 wrote: I am on your side Ken.=C2- Roger should should reference the schematic an d the laws of physics to explain why too little of a load can damage the re ctifier/regulator.=C2- The greater the current, the greater the heat.=C2 - A small load will result in less heat. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480834#480834 - S - WIKI - - =C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin. ________________________________ Message 13 ____________________________________ Time: 05:18:53 PM PST US Subject: AeroElectric-List: Re: Ducati Regulator (too little load) From: "user9253" Agreed. Some regulators regulate by adding a parallel resistance to short out excess current. Some regulators regulate by adding a series resistance to limit the current. Some regulators regulate by turning the output on and off rapidly. The ratio between the on time and the off time controls the average current. The Ducati is the on-off type. It does not waste as much heat as the first two types. But it still gets very warm due to IR losses. The greater the load, the greater the heat. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480836#480836 ________________________________ Message 14 ____________________________________ Time: 05:34:41 PM PST US Subject: Re: AeroElectric-List: Re: Ducati Regulator (too little load) From: GTH Le 13/06/2018 01:25, user9253 a crit: > > I am on your side Ken. Roger should should reference the schematic and the laws of physics to explain why too little of a load can damage the rectifier/regulator. The greater the current, the greater the heat. A small load will result in less heat. > Hi all, I'll second that. In the 15-18 past years we have been seeing lots of opinions about the Rotax rectifier/regulator, but unfortunately very few hard data by people who actually conducted experiments. To date I am not aware of any data in addition to those we obtained during our build, a short report of which can be seen here on Contrails ! http://contrails.free.fr/elec_ducati_en.php More accurate versions of my schematics have been published since, but no further bench tests have been reported. FWIW ________________________________ Message 15 ____________________________________ Time: 06:13:34 PM PST US From: Ken Ryan Subject: Re: AeroElectric-List: Re: Ducati Regulator (too little load) Thank you Joe and Ernest. On Tue, Jun 12, 2018 at 3:32 PM user9253 wrote: > > I am on your side Ken. Roger should should reference the schematic and > the laws of physics to explain why too little of a load can damage the > rectifier/regulator. The greater the current, the greater the heat. A > small load will result in less heat. > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=480834#480834 > > ________________________________ Message 16 ____________________________________ Time: 06:28:15 PM PST US Subject: Re: AeroElectric-List: Re: Ducati Regulator (too little load) From: Lyle Peterson Thinking, and that for me is dangerous. The alternator in a Ducati or similar system is not controlled. It's output is dependent on its RPM. I have two Honda motorcycles that use the same type of system. To test the alternator one checks the output voltage from each of three windings. The expected voltage is in the range of 45 to 70 volts on each winding. When the vehicle system is not demanding any output from the rectifier/regulator the alternator output must go somewhere. It is converted to heat. Heat is the enemy of electronics. I may be way out in left field on this but it makes some sense to me. I have one failure of the charging system on my Hondas. It was the regulator. My wonderful wife brought the car so we could put a little charge in the battery. It took two or three charges to get home. I miss that lady so much. This would be hard to do with an airplane. Lyle On 6/12/2018 8:12 PM, Ken Ryan wrote: > Thank you Joe and Ernest. > > On Tue, Jun 12, 2018 at 3:32 PM user9253 > wrote: > > > > > I am on your side Ken. Roger should should reference the > schematic and the laws of physics to explain why too little of a > load can damage the rectifier/regulator. The greater the current, > the greater the heat. A small load will result in less heat. > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=480834#480834 > > > ========== > - > Electric-List" rel="noreferrer" > target="_blank">http://www.matronics.com/Navigator?AeroElectric-List > ========== > FORUMS - > eferrer" target="_blank">http://forums.matronics.com > ========== > WIKI - > errer" target="_blank">http://wiki.matronics.com > ========== > b Site - > -Matt Dralle, List Admin. > rel="noreferrer" target="_blank">http://www.matronics.com/contribution > ========== > > ________________________________ Message 17 ____________________________________ Time: 07:08:04 PM PST US Subject: AeroElectric-List: Re: Sequence for bringing alternators on line. From: "user9253" The two relays and starter contactor should all have diodes just like the battery contactor does. Connect banded end of diodes to positive. Can the start switch handle the start contactor coil current? Or is the E-123 Relay necessary? -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=480840#480840 ________________________________ Message 18 ____________________________________ Time: 09:56:03 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Ducati Regulator (too little load) At 07:18 PM 6/12/2018, you wrote: Agreed. Some regulators regulate by adding a parallel resistance to short out excess current. nobody does that any more . . . VERY inefficient. The silicon controlled bridge rectifier, series control rectifier=regulator is teh gold standard. Ducatti is but one example. https://goo.gl/yYYeM5 Some regulators regulate by adding a series resistance to limit the current. Not even sure how that would be done . . . ever see a schematic? Some regulators regulate by turning the output on and off rapidly. The ratio between the on time and the off time controls the average current. The Ducati is the on-off type. It does not waste as much heat as the first two types. But it still gets very warm due to IR losses. The greater the load, the greater the heat. This kind-of describes the full-wave bridge circuit cited above. The 'duty cycle' management is rather coarse. The SCR's are triggered on the UPswing of the AC waveform any time the bus is perceived to be below setpoint. But unlike series switches controlled by precision comparators, the silicon controlled rectifier or triac will not . . . indeed cannot be shut off until the AC waveform goes to zero. So while there is some discrimination for siwtch-on delay after zero crossing, the critter stays 'locked' on until the next zero crossing irrespective of instantaneous bus votlage. Since this can happen as rapidly as every few milliseconds, any raggedness in regulation value is small and insignificant. Here are some typical ripple profiles off an SD8 Dynamo under various conditions. https://goo.gl/tLDCSu Except for the more 'advanced' full wave bridge rectifier-regulators using MOS-Fets, I believe that any rectifier-regulator rated for more than 5A or so will be VERY similar to the Ducatti schematic cited. Bob . . . ________________________________ Message 19 ____________________________________ Time: 09:59:09 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Ducati Regulator (too little load) At 08:27 PM 6/12/2018, you wrote: >Thinking, and that for me is dangerous. > >The alternator in a Ducati or similar system is not controlled. Agreed . . . the alternator output is proportional to engine rpm but the rectifier-regulator is a 'gated' device that disconnects the alternator from the bus on a cycle-by-cycle basis, hence its output IS managed for the purpose of charging batteries and running electrowhizzies . . . 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