---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 03/27/16: 23 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:23 AM - Re: fused or not (Robert L. Nuckolls, III) 2. 05:35 AM - Re: fused or not (bob noffs) 3. 05:40 AM - Re: Re: fused or not (bob noffs) 4. 06:06 AM - Re: fused or not (user9253) 5. 06:06 AM - Re: Help with Link Trainer (Robert L. Nuckolls, III) 6. 06:41 AM - Re: Re: fused or not (C&K) 7. 07:44 AM - Re: Re: Charging circuit: Sanity check (Carlos Trigo) 8. 09:27 AM - Re: Re: fused or not (bob noffs) 9. 10:46 AM - Re: Charging circuit: Sanity check (user9253) 10. 10:59 AM - Re: Re: fused or not (Robert L. Nuckolls, III) 11. 11:34 AM - Re: fused or not (Robert L. Nuckolls, III) 12. 11:34 AM - Re: Re: Charging circuit: Sanity check (Robert L. Nuckolls, III) 13. 01:34 PM - Re: Charging circuit: Sanity check (Robert L. Nuckolls, III) 14. 02:40 PM - Re: Charging circuit: Sanity check (Charlie England) 15. 03:30 PM - Re: Charging circuit: Sanity check (Robert L. Nuckolls, III) 16. 04:23 PM - Re: Charging circuit: Sanity check (user9253) 17. 05:16 PM - Re: Re: Charging circuit: Sanity check (Robert L. Nuckolls, III) 18. 05:17 PM - Re: Charging circuit: Sanity check (Charles Kuss) 19. 06:35 PM - Re: Charging circuit: Sanity check (Robert L. Nuckolls, III) 20. 07:06 PM - Re: Charging circuit: Sanity check (Charlie England) 21. 07:55 PM - How do I stop audio hash noise generated by a new set of NavStrobes? (DeWitt Whittington) 22. 08:57 PM - Re: How do I stop audio hash noise generated by a new set of NavStrobes? (Daniel Hooper) 23. 10:40 PM - fused or not...now keeping noise out..do caps work? (Bob Verwey) ________________________________ Message 1 _____________________________________ Time: 05:23:30 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: fused or not At 07:20 PM 3/26/2016, you wrote: >i am mounting my capacitor about 3 inches from >the main bus.i planned on connecting straight to >the bus main lug with #12 wire and no fuse. should i fuse the cap. for 3'' run? >=C2 bob noffs No . . . that wire is not at-risk for generating any smoke or burning of other wires. No would a fuse prevent the very rare condition where the capacitor goes bad, swells up, smells bad and sometimes bursts . . . the things should be on your periodic replacement list . . . say every 5 years or so. Also consider experiments to see if the capacitor is necessary/useful. I've not been able to measure any operational utility beyond helping us get some PM alternator/rectifiers to self-excite. Bob . . . ________________________________ Message 2 _____________________________________ Time: 05:35:10 AM PST US Subject: Re: AeroElectric-List: fused or not From: bob noffs thanks guys for the info. i am told it is to keep noise out of the ecu. bob noffs On Sun, Mar 27, 2016 at 7:20 AM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 07:20 PM 3/26/2016, you wrote: > > i am mounting my capacitor about 3 inches from the main bus.i planned on > connecting straight to the bus main lug with #12 wire and no fuse. should i > fuse the cap. for 3'' run? > =C3=82 bob noffs > > > No . . . that wire is not at-risk for > generating any smoke or burning of > other wires. No would a fuse prevent > the very rare condition where the capacitor > goes bad, swells up, smells bad and sometimes > bursts . . . the things should be on your > periodic replacement list . . . say every > 5 years or so. > > Also consider experiments to see if the > capacitor is necessary/useful. I've not been > able to measure any operational utility beyond > helping us get some PM alternator/rectifiers > to self-excite. > > > Bob . . . > ________________________________ Message 3 _____________________________________ Time: 05:40:33 AM PST US Subject: Re: AeroElectric-List: Re: fused or not From: bob noffs i guess i don't really know how much a cap. pulls initially. i am sure somewhere i saw a schematic using 12 ga. if this is overkill what is recommended for a 10000uf? bob On Sat, Mar 26, 2016 at 9:59 PM, user9253 wrote: > > 12awg seems way too big. > There is not much danger for a 3" wire shorting out. But capacitors have > been known to short, not likely but possible. > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=454201#454201 > > ________________________________ Message 4 _____________________________________ Time: 06:06:44 AM PST US Subject: AeroElectric-List: Re: fused or not From: "user9253" I do know what wire size to use for a 10000uf capacitor. But a capacitor only draws lots of current when it is first energized. And that is for such a short time (less than a second) that the wire does not even begin to warm up. A wild guess would be to use 18 awg. Maybe someone more knowledgeable will answer. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=454211#454211 ________________________________ Message 5 _____________________________________ Time: 06:06:56 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Help with Link Trainer >[] > Larry, thanks for the picture. That is NOT a d-sub connector. That series of connectors started life in avionics back in the 60s as "Winchester" connectors and eventually picked up by AMP. Originally solder-only they morphed into their "M" series connectors with removable crimp pins. See http://tinyurl.com/hu5wdpj Those use the Series II pins and I think the extraction too looks like this [] http://media.digikey.com/photos/Tyco%20Amp%20Photos/305183.jpg I need to do some more catalog surfing to make sure we get you the right parts but I've got a living room full of grandkids who are going to want to search for Easter eggs when they wake up . . . this year's hunt will have to be inside I think . . . it SNOWED last night. Refresh my memory, do you need to replace one or more of these connectors or just de-pin them for re-installation? Bob . . . ________________________________ Message 6 _____________________________________ Time: 06:41:10 AM PST US Subject: Re: AeroElectric-List: Re: fused or not From: C&K FWIW I agree if there is no battery in the circuit. If there is a battery then my advice would be to forget the capacitor. I've run for many years without a capacitor with a 20 amp PM alternator and a small battery. I've run many different ecu based electronic devices (homemade and commercial) without a problem and without any evidence that a capacitor would add any value. Even running my ignition off that system makes no practical difference. Who needs extra parts and extra maintenance issues. Lots of urban legend involved with the use of this large capacitor from what I can tell. I'm not saying the battery replaces the capacitor, I'm just saying that I've no experience running without a battery. Ken On 27/03/2016 9:05 AM, user9253 wrote: > > I do know what wire size to use for a 10000uf capacitor. But a capacitor only draws lots of current when it is first energized. And that is for such a short time (less than a second) that the wire does not even begin to warm up. A wild guess would be to use 18 awg. Maybe someone more knowledgeable will answer. > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=454211#454211 > > ________________________________ Message 7 _____________________________________ Time: 07:44:37 AM PST US From: Carlos Trigo Subject: Re: AeroElectric-List: Re: Charging circuit: Sanity check Charlie I didn't get your revised drawing. Will you please re-post it? Thanks Carlos Enviado do meu iPhone No dia 26/03/2016, =C3-s 16:53, Charlie England esc reveu: > Thanks, Joe; responses inserted below. > >> On Sat, Mar 26, 2016 at 11:48 AM, user9253 wrote: >> >> If both alternators are online at the same time, >> over voltage on one alternator could cause both >> over-voltage modules to short and trip their breakers. > You're right, of course. Looks like the only option would be to diode isol ate the alts outputs from each other, and do OV detection behind the diodes. Unfortunately, that induces up to .45V drop, even with Schottky diodes. Mig ht be able to get away with that & still charge the battery properly; might n ot. Would be nice to be able to adjust an internally regulated alternator's o utput... >> >> Considering that many modern avionics can operate >> between 12 and 30 volts, automatic over-voltage >> protection might not be necessary. The battery might >> resist voltage rise for a minute until the pilot reacts to >> the EFIS high voltage warning and shuts off the alternator. > True, but I'd prefer not to depend on my reaction time if the event comes d uring at high workload time. Will keep that option in mind. >> >> There is no automatic switch over to alternator 2 because >> that bottom relay will never drop out while the main bus >> is hot unless alternator 1 breaker is pulled or tripped. > Correct. I've been focused entirely on OV events, and neglected the *under *voltage possibility. Perhaps I can live with that; with undervoltage alerts from the EFIS and battery capacity, I should have a longer safe response wi ndow. >> >> The bottom relay will have to be able to handle full main- >> switch #2 current because very little will flow through >> the diode. The relay contacts short out the diode. > Correct, and I noticed that as I was typing the 1st email. I think I menti oned an omitted 2nd diode. > I've attached a revised drawing with the additional diode, and the NC rela y in the correct position. I also added a fuse link to the feed line for th e auto-transfer supply, for wire protection. Consider the auto-transfer comp onents below the 'hash' line as optional, but desirable to me. > > As drawn, I should be able to pull alt1's CB, close alt2's main supply swi tch, and start the engine. (Start control not included in the drawing.) Afte r engine start, verify 14V from alt2, then close alt1's main supply switch, o pen alt2's supply switch, and close alt1's CB. Then verify 14V from alt1. > > As mentioned in a previous email, I'm not crazy about resetting the CB eve ry flight, but CB specs seem to indicate ~2500 cycle life for pullable CBs, s o it might get the same treatment as Bob's 'battery rotation' concept and be replaced at every 4th or 5th annual. (Even that would be overkill for me; I don't fly that often.) > > An OV fault should bring alt2 online automatically, and I'll add detection to the auto-transfer relay to get notification if it activates alt2. > I'll depend on the EFIS for under-voltage notification and bring alt2 onli ne manually by pulling alt1's CB (would also remove any potential load cause d by the defective alt1). > > Still not locked-in to using the 50A switches, but am still leaning that w ay. Should have drawn the fuse links in this revision, but forgot. Won't for get to install them, though. :-) > > Thanks again, Joe. Any more thoughts, anyone? > > Charlie ________________________________ Message 8 _____________________________________ Time: 09:27:45 AM PST US Subject: Re: AeroElectric-List: Re: fused or not From: bob noffs well........one failure mode of an engine with elec pumps etc. is alternator power only. whether or not i ever need the cap. is another issue but it was recommended i use one. this is for the honda/viking 110 installation. bob On Sun, Mar 27, 2016 at 8:39 AM, C&K wrote: > > FWIW I agree if there is no battery in the circuit. > > If there is a battery then my advice would be to forget the capacitor. > I've run for many years without a capacitor with a 20 amp PM alternator > and a small battery. I've run many different ecu based electronic devices > (homemade and commercial) without a problem and without any evidence that a > capacitor would add any value. Even running my ignition off that system > makes no practical difference. Who needs extra parts and extra maintenance > issues. Lots of urban legend involved with the use of this large capacitor > from what I can tell. I'm not saying the battery replaces the capacitor, > I'm just saying that I've no experience running without a battery. > > Ken > > > On 27/03/2016 9:05 AM, user9253 wrote: > >> >> I do know what wire size to use for a 10000uf capacitor. But a capacitor >> only draws lots of current when it is first energized. And that is for >> such a short time (less than a second) that the wire does not even begin to >> warm up. A wild guess would be to use 18 awg. Maybe someone more >> knowledgeable will answer. >> >> -------- >> Joe Gores >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=454211#454211 >> >> >> >> >> >> >> >> >> >> >> >> > > ________________________________ Message 9 _____________________________________ Time: 10:46:41 AM PST US Subject: AeroElectric-List: Re: Charging circuit: Sanity check From: "user9253" Here is a schematic for you Charlie -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=454223#454223 Attachments: http://forums.matronics.com//files/charlie_457.pdf http://forums.matronics.com//files/charlie_142.jpg ________________________________ Message 10 ____________________________________ Time: 10:59:41 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: fused or not At 08:05 AM 3/27/2016, you wrote: > >I do know what wire size to use for a 10000uf capacitor. But a >capacitor only draws lots of current when it is first >energized. And that is for such a short time (less than a second) >that the wire does not even begin to warm up. A wild guess would be >to use 18 awg. Maybe someone more knowledgeable will answer. that short of run would be fine with 22AWG but most of the TC world uses 20AWG minimum under the cowl just for mechanical robustness. Bob . . . ________________________________ Message 11 ____________________________________ Time: 11:34:10 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: fused or not At 07:33 AM 3/27/2016, you wrote: >thanks guys for the info. i am told it is to keep noise out of the ecu. >=C2 bob noffs That IS the legacy rationale for adding such things and it's a deeply rooted idea did a failure analysis on a modern, 100A alternator that came equipped from the factory with a 680uF electrolytic capacitor mounted right to the back of the alternator. Emacs! I am quite certain that noise from this alternator on EMC laboratory equipment would not be materially reduced for having added the capacitor. I'd LOVE to see an EMC test report that illuminates the 'benefit'. I just purchased a spectrum analyzer that sweeps down to 1Hz and up to 2.4 Ghz. When I begin development testing on the next generation of PM alternator rectifier/regulators for B&C I will quantify the value of adding this component to our airplanes. Bob . . . ________________________________ Message 12 ____________________________________ Time: 11:34:10 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Charging circuit: Sanity check If both alternators are online at the same time, over voltage on one alternator could cause both over-voltage modules to short and trip their breakers. The B&C LR/LS series regulators are fitted with circuits to identify WHICH of two regulators is causing the OV condition. If a regulator is working right, the OV condition drives the field output votlage to zero . . . and OV trip for THAT regulator is inhibited. Hence, only the regulator with a runaway field output is allowed to exercise its circuit breaker. Considering that many modern avionics can operate between 12 and 30 volts, automatic over-voltage protection might not be necessary.=C2 The battery might resist voltage rise for a minute until the pilot reacts to the EFIS high voltage warning and shuts off the alternator. We'd never be allowed to field such a system in TC aircraft. Given that it's so easy to deal with the dual alternator situation, there's no reason to loose much sleep over it. If you've installed two, bare-footed crowbar ov modules, then yes, you'd get a dual trip if both alternators are ON . . . then turn them back on one at a time . . . no big deal. If one alternator is a stand-by and OFF for normal ops, then only the operating alternator's ov protection would operate making diagnostics simpler yet. As drawn, I should be able to pull alt1's CB, close alt2's main supply switch, and start the engine. (Start control not included in the drawing.) After engine start, verify 14V from alt2, then close alt1's main supply switch, open alt2's supply switch, and close alt1's CB. Then verify 14V from alt1. Anytime somebody uses the word 'automatically', my little red head-flags go up. One should first identify the risk for allowing some otherwise automated condition to proceed while awaiting pilot notice and action. For example, suppose you had two, independently controlled alternators driving the same bus structure with one alternator held in reserve by keeping it's field supply open. When the first alternator craps, you get a low voltage warning light . . . if you've done due diligence with respect to your battery, you can finish your coffee, fold and stow a map and then bring the standby alternator on line while taxing your stored battery energy to perhaps 1% of total. In other words, what is the value of adding lots the bells, whistles, diodes, relays, etc. etc? System MTBF is inversely proportional to parts count . . . a part that is NOT installed will NOT be the part that caused you to drag out a toolbox. Do your FMEA study guys . . . and evaluate risk to comfortable completion of flight before you complicate the system. As a general rule, there is little or no value added to OBAM aircraft systems for having incorporated 'automatic' features so popular with the purveyors of push-button systems over the counters at OSH. Bob . . . ________________________________ Message 13 ____________________________________ Time: 01:34:41 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Charging circuit: Sanity check At 05:27 PM 3/25/2016, you wrote: >Greetings, > >I need a sanity check on my current thoughts for >the charging circuit in my RV-7. > >Please note that this is *not* a typical Lyc >installation, so many of the assumed requirements/limits do not apply.=C2 > >Engine: Mazda Renesis automotive conversion with total electrical dependency. > >Alternator(s): 2 ea identical ND internally >regulated alternators, each rated at 60 amps. >(This choice was driven by both budget >constraints and simplicity of installation) > >My goals/choices are: >1. 'Unlimited' availability of electrical power, >to avoid in-route diversion in the case of >alternator failure. I accept a single >battery,due to the very small likelihood of >battery failure. Fuel will easily outlast any >but very big/heavy batteries. A PC680 is good >for only ~45 minutes with only the engine >consuming electrons; much less time with avionics on line. > >2.Redundant paths of power to the buss, due to >the engine's total dependence on electricity.=C2 > >3. Ability to check both alternators for proper operation before flight. Take a peek at this drawing http://tinyurl.com/zpww8ag and see if it doesn't do what you want. All engine stuff runs off battery bus. E-bus has dual feeds one of which mitigates loss of battery contactor. S/B alternator feeds battery directly which also goes to mitigating loss of battery contactor. Simple controls with no hazard to system for having more than one alternator active. Bob . . . ________________________________ Message 14 ____________________________________ Time: 02:40:38 PM PST US Subject: Re: AeroElectric-List: Charging circuit: Sanity check From: Charlie England On 3/27/2016 3:30 PM, Robert L. Nuckolls, III wrote: > At 05:27 PM 3/25/2016, you wrote: >> Greetings, >> >> I need a sanity check on my current thoughts for the charging circuit >> in my RV-7. >> >> Please note that this is *not* a typical Lyc installation, so many of >> the assumed requirements/limits do not apply. >> >> Engine: Mazda Renesis automotive conversion with total electrical >> dependency. >> >> Alternator(s): 2 ea identical ND internally regulated alternators, >> each rated at 60 amps. >> (This choice was driven by both budget constraints and simplicity of >> installation) >> >> My goals/choices are: >> 1. 'Unlimited' availability of electrical power, to avoid in-route >> diversion in the case of alternator failure. I accept a single >> battery,due to the very small likelihood of battery failure. Fuel >> will easily outlast any but very big/heavy batteries. A PC680 is good >> for only ~45 minutes with only the engine consuming electrons; much >> less time with avionics on line. >> >> 2.Redundant paths of power to the buss, due to the engine's total >> dependence on electricity. >> >> 3. Ability to check both alternators for proper operation before flight. > > Take a peek at this drawing > > http://tinyurl.com/zpww8ag > > and see if it doesn't do what you want. > > All engine stuff runs off battery bus. E-bus has dual > feeds one of which mitigates loss of battery contactor. > S/B alternator feeds battery directly which also > goes to mitigating loss of battery contactor. Simple > controls with no hazard to system for having more than > one alternator active. > > > Bob . . . > Looks good, but do I need multiple busses, when I'll be running 2 identical alternators? The auto conversion engine has the advantage that I'm not restricted to a vacuum pad mount for the 2nd alt, like a Lyc would be. So the entire aircraft's electrical loads can be supported by either alternator. I'd prefer internally regulated alternators, as well. I've followed others' issues with them in the past, but I've used them on my RV-4's for years and I'm comfortable with them. I won't be 'load dumping' unless the alternator has already failed. My only real concern would be pre-flight testing of both alternators. My hope would be engine start with only the backup alternator on line, check for proper operation, then take the backup off line (while operating at low power) and bring the primary on line to verify its operation. Do you see any issues with this? Thanks, Charlie ________________________________ Message 15 ____________________________________ Time: 03:30:32 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Charging circuit: Sanity check Looks good, but do I need multiple busses, when I'll be running 2 identical alternators? Not sure what you mean . . . eliminate the e-bus? Sure, you can do that. The auto conversion engine has the advantage that I'm not restricted to a vacuum pad mount for the 2nd alt, like a Lyc would be. So the entire aircraft's electrical loads can be supported by either alternator. Understand. The drawing as submitted supports that requirement. I'd prefer internally regulated alternators, as well. I've followed others' issues with them in the past, but I've used them on my RV-4's for years and I'm comfortable with them. I won't be 'load dumping' unless the alternator has already failed. That's what I have illustrated . . . Load dumping damage is a will-o-the-whisp that arose from the smoke with alternators popular in the RV crowd many years ago. I think those were some product offered by Van's. Read the chapter on alternators for a description of how ANY alternator remanufactured by ANY reputable shop demonstrates MULTIPLE max rpm, max load, max temperature load dumps. My only real concern would be pre-flight testing of both alternators. You can do that. In fact, the airplane can be routinely flown on either alternator. My hope would be engine start with only the backup alternator on line, check for proper operation, then take the backup off line (while operating at low power) and bring the primary on line to verify its operation. That or any other combination of switch-flips are equally valid . . . I've revised the drawing to eliminate the e-bus. You still want to connect the s/b alternator directly to the battery so that shutting down the DC PWR MASTER gets the electrical system max-cold . . . for smoke in the cockpit events. See http://tinyurl.com/zm46jzm Bob . . . ________________________________ Message 16 ____________________________________ Time: 04:23:37 PM PST US Subject: AeroElectric-List: Re: Charging circuit: Sanity check From: "user9253" One bus is OK, but consider: Is it possible for that bus to lose power? If it does lose power, what are the symptoms? If loads critical to flight safety get power from that bus, what is the backup plan? Having two alternators does not necessarily mean that the main power bus will not lose power. It all depends on how the aircraft is wired. The ignition and fuel pump of an electrically dependent engine should be powered directly from the battery. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=454238#454238 ________________________________ Message 17 ____________________________________ Time: 05:16:47 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Charging circuit: Sanity check At 06:21 PM 3/27/2016, you wrote: > >One bus is OK, but consider: >Is it possible for that bus to lose power? >If it does lose power, what are the symptoms? >If loads critical to flight safety get power from >that bus, what is the backup plan? >Having two alternators does not necessarily mean that the >main power bus will not lose power. It all depends on how >the aircraft is wired. >The ignition and fuel pump of an electrically dependent >engine should be powered directly from the battery. As a general rule, the reliability of a well crafted bus structure is as robust as prop-bolts. The reason for multiple busses in the z-figures speaks efficient utilization of a limited resource . . . in the case of Z-11, batty only flight. In the case of Z-13/8, limits of output on an 8A PM alternator. In the case of electrically dependent engines, running all the engine stuff from the battery bus keeps the fan blowing with all other electrical system shut down. Z-12 is illustrative of bus structure on thousands of TC aircraft flying an SD-20 s/b alternator. One battery, two alternators, one bus . . . oh yeah, they DO have an avionics bus but those don't count . . . they serve no practical or necessary energy management purpose. In no instance was a bus added to 'back up' another bus. It's existence facilitates partitioning energy delivery onto narrowly defined tasks under specific circumstances. Bob . . . ________________________________ Message 18 ____________________________________ Time: 05:17:59 PM PST US From: Charles Kuss Subject: Re: AeroElectric-List: Charging circuit: Sanity check snipped The auto conversion engine has the advantage that I'm not restricted to a vacuum pad mount for the 2nd alt, like a Lyc would be. So the entire aircraft's electrical loads can be supported by either alternator. snipped Are both these alternators going to be belt driven? If so, when one belt breaks, it often fouls the belt for the second alternator and causes it to jump off it's pulleys. Thus, a single belt failure can disable BOTH alternators. Bob's been designing this stuff for over 30 years. How much time/thought did you put into your design? In a failure of all the power generating sources [alternators/dynamos/generators] it would behoove you to have an essential bus, to rapidly shed unneeded power. Also consider a smaller, secondary battery, to power this bus. Charlie ________________________________ Message 19 ____________________________________ Time: 06:35:18 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Charging circuit: Sanity check > >Are both these alternators going to be belt driven? If so, when one >belt breaks, it often fouls the belt for the second alternator and >causes it to jump off it's pulleys. Thus, a single belt failure can >disable BOTH alternators. Excellent question . . . if this is a high-risk event irrespective of probability, then replacing the belt every 100 hrs or so seems prudent. Also, use Gates belts if you can get 'em . . . Plan B might include a detailed load analysis after having shed all non-essential loads while maintaining battery capacity at useful endurance levels. Bob . . . ________________________________ Message 20 ____________________________________ Time: 07:06:48 PM PST US Subject: Re: AeroElectric-List: Charging circuit: Sanity check From: Charlie England CgotLS0tLS0tLSBPcmlnaW5hbCBtZXNzYWdlIC0tLS0tLS0tCkZyb206ICJSb2JlcnQgTC4gTnVj a29sbHMsIElJSSIKRGF0ZTowMy8yNy8yMDE2IDg6MzEgUE0gKEdNVC0wNjowMCkKVG86IGFlcm9l bGVjdHJpYy1saXN0QG1hdHJvbmljcy5jb20KU3ViamVjdDogUmU6IEFlcm9FbGVjdHJpYy1MaXN0 OiBDaGFyZ2luZyBjaXJjdWl0OiBTYW5pdHkgY2hlY2sKCgpBcmUgYm90aCB0aGVzZSBhbHRlcm5h dG9ycyBnb2luZyB0byBiZSBiZWx0IGRyaXZlbj8gSWYgc28sIHdoZW4gb25lIGJlbHQgYnJlYWtz LCBpdCBvZnRlbiBmb3VscyB0aGUgYmVsdCBmb3IgdGhlIHNlY29uZCBhbHRlcm5hdG9yIGFuZCBj YXVzZXMgaXQgdG8ganVtcCBvZmYgaXQncyBwdWxsZXlzLiBUaHVzLCBhIHNpbmdsZSBiZWx0IGZh aWx1cmUgY2FuIGRpc2FibGUgQk9USCBhbHRlcm5hdG9ycy4KCiAgRXhjZWxsZW50IHF1ZXN0aW9u IC4gLiAuIGlmIHRoaXMgaXMgYSBoaWdoLXJpc2sKICBldmVudCBpcnJlc3BlY3RpdmUgb2YgcHJv YmFiaWxpdHksIHRoZW4gcmVwbGFjaW5nCiAgdGhlIGJlbHQgZXZlcnkgMTAwIGhycyBvciBzbyBz ZWVtcyBwcnVkZW50LiBBbHNvLAogIHVzZSBHYXRlcyBiZWx0cyBpZiB5b3UgY2FuIGdldCAnZW0g LiAuIC4gCgogIFBsYW4gQiBtaWdodCBpbmNsdWRlIGEgZGV0YWlsZWQgbG9hZCBhbmFseXNpcyBh ZnRlcgogIGhhdmluZyBzaGVkIGFsbCBub24tZXNzZW50aWFsIGxvYWRzIHdoaWxlIG1haW50YWlu aW5nCiAgYmF0dGVyeSBjYXBhY2l0eSBhdCB1c2VmdWwgZW5kdXJhbmNlIGxldmVscy4gCgoKICBC b2IgLiAuIC4KClNvcnJ5IEkgaGF2ZW4ndCBiZWVuIG9uIG11Y2ggdG9kYXk7IGludGVybWl0dGVu dCBob3VzZSBwb3dlciBhbGwgZGF5LiAKClR5cGluZyBvbiBteSBwaG9uZS4gCgpCb3RoIHdpbGwg bGlrZWx5IGJlIGJlbHQgZHJpdmVuLCBidXQgSSBoYXZlbid0IGxvc3QgYSBiZWx0IG9uIGFueSBv ZiBteSB2ZWhpY2xlcyBpbiBhdCBsZWFzdCAzMCB5ZWFycyBvZiBuZWdsZWN0aW5nIHRoZW0uIE5v dCBpZ25vcmluZyB0aGUgcG9zc2liaWxpdHksIGJ1dCBJIGNhbid0IGNvbXBsYWluIGFib3V0IHRo ZSBvZGRzLiAgOi0pCgpJIGFtIGNvbnNpZGVyaW5nIGRpcmVjdCBkcml2ZSBmb3Igb25lLiBDcnVp c2UgcnBtIHdpbGwgYmUgNTUwMC02MDAwIHNvIHNob3VsZCBiZSBlbm91Z2ggdG8ga2VlcCBjaGFy Z2luZyBldmVuIGRpcmVjdCBkcml2ZS4gCgpDaGFybGll ________________________________ Message 21 ____________________________________ Time: 07:55:31 PM PST US From: DeWitt Whittington Subject: AeroElectric-List: How do I stop audio hash noise generated by a new set of NavStrobes? Hello, Bob, and all you AeroElectric forum participants. This is the first time Ive posted in years, but Ive got a problem I cant solve. At Oshkosh 2015 I bought a set of the NavStrob LED nav/position light units. They directly replace the red and green wingtip nave bulbs, and the white rear position light. I cleaned out the sockets for all three locations and sprayed them with CorrosionX. Then inserted the NavStrobe units. When you turn on the Nav light switch once, all three burn with a steady light. Flip them off, and turn on again, and they flash like strobes. Slick. But, in my 1975 172L, when we turn on the COM radios, then turn on the strobes, there is a very unpleasant hash noise when the VOX gate opens as when you speak or a transmission comes in from someone else. The designer of the NavStrobe unit suggests cleaning all the light sockets again. And if that doesnt get rid of the hash noise (and it didnt) install a choke coil. So, any suggestions? And what size or type of choke should I buy and where do I install it? All suggestions welcome. Dee Whittington ________________________________ Message 22 ____________________________________ Time: 08:57:59 PM PST US From: Daniel Hooper Subject: Re: AeroElectric-List: How do I stop audio hash noise generated by a new set of NavStrobes? It could possibly be ground noise. What is the wiring configuration for your nav lights and intercom? --Daniel > On Mar 27, 2016, at 9:52 PM, DeWitt Whittington wrote: > > > Hello, Bob, and all you AeroElectric forum participants. This is the first time Ive posted in years, but Ive got a problem I cant solve. At Oshkosh 2015 I bought a set of the NavStrob LED nav/position light units. They directly replace the red and green wingtip nave bulbs, and the white rear position light. I cleaned out the sockets for all three locations and sprayed them with CorrosionX. Then inserted the NavStrobe units. When you turn on the Nav light switch once, all three burn with a steady light. Flip them off, and turn on again, and they flash like strobes. Slick. But, in my 1975 172L, when we turn on the COM radios, then turn on the strobes, there is a very unpleasant hash noise when the VOX gate opens as when you speak or a transmission comes in from someone else. > > The designer of the NavStrobe unit suggests cleaning all the light sockets again. And if that doesnt get rid of the hash noise (and it didnt) install a choke coil. > > So, any suggestions? And what size or type of choke should I buy and where do I install it? All suggestions welcome. > > Dee Whittington > > > > > > > ________________________________ Message 23 ____________________________________ Time: 10:40:48 PM PST US From: Bob Verwey Subject: AeroElectric-List: fused or not...now keeping noise out..do caps work? Bob, In the same vein... After having a new intercom fitted in my radio stack, I have developed a serious amount of radio noise as soon as the rpm's hit the 2000 mark. The sq button has no effect on the severity of this noise. It is as if a source is transmitting to the radio! I am told that adding a 22000 microfarad cap across the power feed to the radios will solve this problem. What says the brains trust? On 27 March 2016 at 19:39, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 07:33 AM 3/27/2016, you wrote: > > thanks guys for the info. i am told it is to keep noise out of the ecu. > =C3=82 bob noffs > > > That IS the legacy rationale for adding such things > and it's a deeply rooted idea did > a failure analysis on a modern, 100A alternator > that came equipped from the factory with a 680uF > electrolytic capacitor mounted right to the back > of the alternator. > > > [image: Emacs!] > > I am quite certain that noise from this alternator on > EMC laboratory equipment would not be materially > reduced for having added the capacitor. I'd > LOVE to see an EMC test report that illuminates > the 'benefit'. > > I just purchased a spectrum analyzer that sweeps > down to 1Hz and up to 2.4 Ghz. When I begin > development testing on the next generation of > PM alternator rectifier/regulators for B&C I will > quantify the value of adding this component > to our airplanes. > > > Bob . . . > -- Best... 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